WorldWideScience

Sample records for extremely limited resources

  1. Limited Income and Resources

    Data.gov (United States)

    U.S. Department of Health & Human Services — Information for those with limited income and resources (those who may qualify for or already have the Low Income Subsidy to lower their prescription drug coverage...

  2. Extreme Physics and Informational/Computational Limits

    Energy Technology Data Exchange (ETDEWEB)

    Di Sia, Paolo, E-mail: paolo.disia@univr.it, E-mail: 10alla33@virgilio.it [Department of Computer Science, Faculty of Science, Verona University, Strada Le Grazie 15, I-37134 Verona (Italy) and Faculty of Computer Science, Free University of Bozen, Piazza Domenicani 3, I-39100 Bozen-Bolzano (Italy)

    2011-07-08

    A sector of the current theoretical physics, even called 'extreme physics', deals with topics concerning superstring theories, multiverse, quantum teleportation, negative energy, and more, that only few years ago were considered scientific imaginations or purely speculative physics. Present experimental lines of evidence and implications of cosmological observations seem on the contrary support such theories. These new physical developments lead to informational limits, as the quantity of information, that a physical system can record, and computational limits, resulting from considerations regarding black holes and space-time fluctuations. In this paper I consider important limits for information and computation resulting in particular from string theories and its foundations.

  3. Extremely Correlated Limit of the Hubbard Model

    OpenAIRE

    Perepelitsky, Edward

    2014-01-01

    In this work, we describe the simplifications to the Extremely Correlated Fermi Liquid Theory (ECFL) \\cite{ECFL, Monster} which occur in the limit of infinite spatial dimensions. In particular, we show that the single-particle electron Green's function G(k) can be written in terms of two momentum-independent self-energies. Moreover, we elucidate the nature of the ECFL \\lambda expansion in the limit of infinite dimensions and carry out this expansion explicitly to O(\\lambda^2). Additionally, w...

  4. Reconnectable Network with Limited Resources

    Institute of Scientific and Technical Information of China (English)

    史维更

    1991-01-01

    The reachability of a strongly connected network may be destroyed after link damage.Since many networks are directed or equivalent directed,connected by directed links with the potential for reversal.Therefore the reachability can be restored by reversing the direction of links.[1] has studied this matter under unlimited resources (transmitter and receiver) condition.In this paper the reconnectability of a network with limited number of receivers and transmitters is discussed.Also a linear time algorithm is given to find a reconnected reversal for limited receivers and transmitters.

  5. Prospective Optimization with Limited Resources.

    Science.gov (United States)

    Snider, Joseph; Lee, Dongpyo; Poizner, Howard; Gepshtein, Sergei

    2015-09-01

    The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation") and how often they attempted to incorporate new information about the future rewards (their "recalculation period"). We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation.

  6. Prospective Optimization with Limited Resources.

    Directory of Open Access Journals (Sweden)

    Joseph Snider

    2015-09-01

    Full Text Available The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation" and how often they attempted to incorporate new information about the future rewards (their "recalculation period". We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation.

  7. To the limit of extreme malnutrition

    DEFF Research Database (Denmark)

    Frølich, Jacob; Buskbjerg, Camilla Viola; Støving, Rene K

    2016-01-01

    Extreme malnutrition with body mass index (BMI) as low as 10 kg/m(2) is not uncommon in anorexia nervosa, with survival enabled through complex metabolic adaptations. In contrast, outcomes from hunger strikes and famines are usually fatal after weight loss to about 40% below expected body weight,...

  8. Limitations of Extreme Nonlinear Ultrafast Nanophotonics

    Directory of Open Access Journals (Sweden)

    Kern Christian

    2015-01-01

    Full Text Available High-harmonic generation (HHG has been established as an indispensable tool in optical spectroscopy. This effect arises for instance upon illumination of a noble gas with sub-picosecond laser pulses at focussed intensities significantly greater than 1012W/cm2. HHG provides a coherent light source in the extreme ultraviolet (XUV spectral region, which is of importance in inner shell photo ionization of many atoms and molecules. Additionally, it intrinsically features light fields with unique temporal properties. Even in its simplest realization, XUV bursts of sub-femtosecond pulse lengths are released. More sophisticated schemes open the path to attosecond physics by offering single pulses of less than 100 attoseconds duration.

  9. Extremal limits and Ba\\~nados-Silk-West effect

    CERN Document Server

    Pradhan, Parthapratim

    2016-01-01

    A fascinating property of extremal Kerr black hole (BH) is that it could be act as a particle accelerator with infinite high center-of-mass (CM) energy \\cite{bsw}. In this note, we would like to discuss about such fascinating result and to point out that this infinite energy at the event horizon comes solely due \\emph{to the singular nature of the extremal limit}. We also show that a non-extremal Kerr BH can \\emph{not} transform into extremal Kerr BH by the Ba\\~{n}ados-Silk-West mechanism. Moreover, we discuss about three possible geometries (near extremal, purely extremal and near horizon of extremal Kerr) of this mechanism. We further prove that near extremal geometry and near horizon geometry, precisely extremal geometry of extremal Kerr BHs are qualitatively different. Near extremal geometry and near horizon geometry gives the CM energy is finite, whereas precisely extremal geometry gives the diverging energy. Thus, we can argue that extremal Kerr BH and non-extremal Kerr BH are quite distinct objects. Fi...

  10. Limited resources in a driven diffusion process.

    Science.gov (United States)

    Brackley, Chris A; Romano, M Carmen; Grebogi, Celso; Thiel, Marco

    2010-08-13

    The advance of particles in many driven diffusion systems depends on the availability of resources in the surrounding environment. In the balance between supply and demand of such resources we are confronted with a regime in which, under limited resource availability, the flow is markedly reduced. In the context of mRNA translation this represents the finite availability of amino acid-tRNA molecules. In this limited resources regime a severe depletion of amino acid tRNAs is also observed. These dramatic effects are vital to our understanding of translation, and are likely to also be important for the many other applications of driven diffusion models.

  11. Extreme Risk In Resource Indices And The Generalized Logistic Distribution

    National Research Council Canada - National Science Library

    Chun-Kai Huang; Venelle Pather; Jahvaid Hammujuddy; Knowledge Chinhamu

    2017-01-01

    .... In this article, we compare performances of classical extreme value models against the recently suggested generalized logistic distribution, for estimating value-at-risk and expected shortfall in resource indices...

  12. On the Limit Distribution of Lower Extreme Generalized Order Statistics

    Indian Academy of Sciences (India)

    H M Barakat; Magdy E El-Adll

    2012-05-01

    In a wide subclass of generalized order statistics $(gOs)$, which contains most of the known and important models of ordered random variables, weak convergence of lower extremes are developed. A recent result of extreme value theory of $m-gOs$ (as well as the classical extreme value theory of ordinary order statistics) yields three types of limit distributions that are possible in case of linear normalization. In this paper a similar classification of limit distributions holds for extreme $gOs$, where the parameters $_j,j=1,\\ldots,n$, are assumed to be pairwise different. Two illustrative examples are given to demonstrate the practical importance for some of the obtained results.

  13. Food Cravings Consume Limited Cognitive Resources

    Science.gov (United States)

    Kemps, Eva; Tiggemann, Marika; Grigg, Megan

    2008-01-01

    Using Tiffany's (1990) cognitive model of drug use and craving as a theoretical basis, the present experiments investigated whether cravings for food expend limited cognitive resources. Cognitive performance was assessed by simple reaction time (Experiment 1) and an established measure of working memory capacity, the operation span task…

  14. Limitation of computational resource as physical principle

    CERN Document Server

    Ozhigov, Y I

    2003-01-01

    Limitation of computational resources is considered as a universal principle that for simulation is as fundamental as physical laws are. It claims that all experimentally verifiable implications of physical laws can be simulated by the effective classical algorithms. It is demonstrated through a completely deterministic approach proposed for the simulation of biopolymers assembly. A state of molecule during its assembly is described in terms of the reduced density matrix permitting only limited tunneling. An assembly is treated as a sequence of elementary scatterings of simple molecules from the environment on the point of assembly. A decoherence is treated as a forced measurement of quantum state resulted from the shortage of computational resource. All results of measurements are determined by a choice from the limited number of special options of the nonphysical nature which stay unchanged till the completion of assembly; we do not use the random numbers generators. Observations of equal states during the ...

  15. On the design of experiments to study extreme field limits

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S. S.; Chen, M.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J. K.; Zhidkov, A. G.; Chen, P.; Mur, V. D.; Narozhny, N. B.; Popov, V. S.; Thomas, A. G. R.; Korn, G. [University of California, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States) and University of California, Berkeley, California 94720 (United States); Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); Osaka University, Osaka 565-0871 (Japan); Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Moscow Engineering Physics Institute (State University), Moscow 115409 (Russian Federation); Institute of Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); University of Michigan, Ann Arbor, Michigan 48103 (United States); Max-Planck-Institut fur Quantenoptik, Garching 85748 (Germany) and ELI Beamline Facility, Institute of Physics, Czech Academy of Sciences, Prague 18221 (Czech Republic)

    2012-12-21

    We propose experiments on the collision of high intensity electromagnetic pulses with electron bunches and on the collision of multiple electromagnetic pulses for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The effects of nonlinear QED will be revealed in these laser plasma experiments.

  16. On the design of experiments to study extreme field limits

    CERN Document Server

    Bulanov, S S; Schroeder, C B; Esarey, E; Leemans, W P; Bulanov, S V; Esirkepov, T Zh; Kando, M; Koga, J K; Zhidkov, A G; Chen, P; Mur, V D; Narozhny, N B; Popov, V S; Thomas, A G R; Korn, G

    2012-01-01

    We propose experiments on the collision of high intensity electromagnetic pulses with electron bunches and on the collision of multiple electromagnetic pulses for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The effects of nonlinear QED will be revealed in these laser plasma experiments.

  17. Assignation of limited resources in pediatrics

    Directory of Open Access Journals (Sweden)

    Garduño Espinosa Armando

    2014-07-01

    Full Text Available Limited resources assignation is fundamental in the development of health services and since they will never be enough, justice is- sues arise. Many distributive justice theories are discussed: liberal, equilable and utilitarian, as well as ethic principles and cost-benefit relation, that is, the consequences. Palliative medicine is suggested as a strategy to reduce the cost of hospitable care and to enhance its designation.

  18. Indoor climate optimization with limited resources

    DEFF Research Database (Denmark)

    Santos, A.; Gunnarsen, Lars Bo

    This report presents experimental data and models for optimisation of the indoor climate parameters temperature, noise, draught and window opening. Results are based on experiments with human subjects performed in climate chambers at University of the Philippines. The report may assist building...... designers to balance attention and resources between the parameters of the indoor climate when resources are less than optimal....

  19. PRACE resources to study extreme natural events: the SCENE project

    Science.gov (United States)

    Fiori, Elisabetta; Galizia, Antonella; Danovaro, Emanuele; Clematis, Andrea; Bedrina, Tatiana; Parodi, Antonio

    2014-05-01

    Forecasting severe storms and floods is one of the main challenges of 21th century. Floods are the most dangerous meteorological hazard in the Mediterranean basins due to both the number of people affected and to the relatively high frequency by which human activities and goods suffer damages and losses. The numerical simulations of extreme events which happen over small basins as the Mediterranean ones are need a very fine-resolution in space and time and as a consequence considerable memory and computational power are required. Since the resources provided by the PRACE project represent the solution for satisfying such requirements, the Super Computing of Extreme Natural Events (SCENE) project has been proposed. SCENE aims to provide an advanced understanding of the intrinsic predictability of severe precipitation processes and the associated predictive ability of high-resolution meteorological models with a special focus on flash flood-producing storms in regions of complex orography (e.g. Mediterranean area) through the assessment of the role of both the convective and microphysical processes. The meteorological model considered in the project is the Weather Research and Forecasting (WRF) model, a state of the art mesoscale numerical weather prediction system designed to serve both operational forecasting and atmospheric research needs. Thus, among all the parameterizations available in the WRF model, the WRF Single-Moment 6-Class Scheme and the Thompson microphysics scheme will be adopted for the numerical simulations in combination with three different approaches for the treatment of the convective processes, that is the use of explicit method, Betts-Miller-Janjic Scheme and Kain-Fritsch. As for flash-flood producing storms, the project considers the recent sequence of extreme events occurred in the north-western portion of the Mediterranean sea; some of these events are the so-called critical cases of the DRIHM project (www.drihm.eu), i.e. selected severe

  20. Addition of multiple limiting resources reduces grassland diversity

    NARCIS (Netherlands)

    Harpole, W Stanley; Sullivan, Lauren L; Lind, Eric M; Firn, Jennifer; Adler, Peter B; Borer, Elizabeth T; Chase, Jonathan; Fay, Philip A; Hautier, Yann; Hillebrand, Helmut; MacDougall, Andrew S; Seabloom, Eric W; Williams, Ryan; Bakker, Jonathan D; Cadotte, Marc W; Chaneton, Enrique J; Chu, Chengjin; Cleland, Elsa E; D'Antonio, Carla; Davies, Kendi F; Gruner, Daniel S; Hagenah, Nicole; Kirkman, Kevin; Knops, Johannes M H; La Pierre, Kimberly J; McCulley, Rebecca L; Moore, Joslin L; Morgan, John W; Prober, Suzanne M; Risch, Anita C; Schuetz, Martin; Stevens, Carly J; Wragg, Peter D

    2016-01-01

    Niche dimensionality provides a general theoretical explanation for biodiversity-more niches, defined by more limiting factors, allow for more ways that species can coexist. Because plant species compete for the same set of limiting resources, theory predicts that addition of a limiting resource eli

  1. Extremely correlated Fermi liquids in the limit of infinite dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Perepelitsky, Edward, E-mail: eperepel@ucsc.edu; Sriram Shastry, B.

    2013-11-15

    We study the infinite spatial dimensionality limit (d→∞) of the recently developed Extremely Correlated Fermi Liquid (ECFL) theory (Shastry 2011, 2013) [17,18] for the t–J model at J=0. We directly analyze the Schwinger equations of motion for the Gutzwiller projected (i.e. U=∞) electron Green’s function G. From simplifications arising in this limit d→∞, we are able to make several exact statements about the theory. The ECFL Green’s function is shown to have a momentum independent Dyson (Mori) self energy. For practical calculations we introduce a partial projection parameter λ, and obtain the complete set of ECFL integral equations to O(λ{sup 2}). In a related publication (Zitko et al. 2013) [23], these equations are compared in detail with the dynamical mean field theory for the large U Hubbard model. Paralleling the well known mapping for the Hubbard model, we find that the infinite dimensional t–J model (with J=0) can be mapped to the infinite-U Anderson impurity model with a self-consistently determined set of parameters. This mapping extends individually to the auxiliary Green’s function g and the caparison factor μ. Additionally, the optical conductivity is shown to be obtainable from G with negligibly small vertex corrections. These results are shown to hold to each order in λ. -- Highlights: •Infinite-dimensional t–J model (J=0) studied within new ECFL theory. •Mapping to the infinite U Anderson model with self consistent hybridization. •Single particle Green’s function determined by two local self energies. •Partial projection through control variable λ. •Expansion carried out to O(λ{sup 2}) explicitly.

  2. Central-line-associated bloodstream infections in a resource-limited ...

    African Journals Online (AJOL)

    weight (<2 500 g), 13% were very-low-birth-weight (<1 500 g) and 6% were extremely ... resource-limited South African neonatal intensive care unit. C Geldenhuys,1 MB .... s[11] wound classification was used to classify the wounds of all the ...

  3. Life at extreme limits: the anaerobic halophilic alkalithermophiles.

    Science.gov (United States)

    Mesbah, Noha M; Wiegel, Juergen

    2008-03-01

    The ability of anaerobic microorganisms to proliferate under extreme conditions is of widespread importance for microbial physiology, remediation, industry, and evolution. The halophilic alkalithermophiles are a novel group of polyextremophiles. Tolerance to alkaline pH, elevated NaCl concentrations, and high temperatures necessitates mechanisms for cytoplasmic pH acidification; permeability control of the cell membrane; and stability of proteins, the cell wall, and other cellular constituents to multiple extreme conditions. Although it is generally assumed that extremophiles growing at more than one extreme combine adaptive mechanisms for each individual extreme, adaptations for individual extremes often counteract each other. However, in alkaline, hypersaline niches heated via intense solar irradiation, culture-independent analyses have revealed the presence of an extensive diversity of aerobic and anaerobic microorganisms belonging to Bacteria and Archaea that survive and grow under multiple harsh conditions. Thus, polyextremophiles must have developed novel adaptive strategies enabling them to grow and proliferate under multiple extreme conditions. The recent isolation of two novel anaerobic, halophilic alkalithermophiles, Natranaerobius thermophilus and Halonatronum saccharophilum, will provide a platform for detailed biochemical, genomic, and proteomic experiments, allowing a greater understanding of the novel adaptive mechanisms undoubtedly employed by polyextremophiles. In this review, we highlight growth characteristics, ecology, and phylogeny of the anaerobic halophilic alkalithermophiles isolated. We also describe the bioenergetic and physiological problems posed by growth at the multiple extreme conditions of alkaline pH, high NaCl concentration, and elevated temperature under anoxic conditions and highlight recent findings and unresolved problems regarding adaptation to multiple extreme conditions.

  4. Extremal Black holes and the limits of the third law

    CERN Document Server

    Liberati, S; Sonego, S; Liberati, Stefano; Rothman, Tony; Sonego, Sebastiano

    2001-01-01

    Recent results of quantum field theory on a curved spacetime suggest that extremal black holes are not thermal objects and that the notion of zero temperature is ill-defined for them. If this is correct, one may have to go to a full semiclassical theory of gravity, including backreaction, in order to make sense of the third law of black hole thermodynamics. Alternatively, it is possible that we shall have to drastically revise the status of extremality in black hole thermodynamics.

  5. Selection by pairwise comparisons with limited resources

    Science.gov (United States)

    Laureti, Paolo; Mathiesen, Joachim; Zhang, Yi-Cheng

    2004-07-01

    We analyze different methods of sorting and selecting a set of objects by their intrinsic value, via pairwise comparisons whose outcome is uncertain. After discussing the limits of repeated Round Robins, two new methods are presented: The ran-fil requires no previous knowledge on the set under consideration, yet displaying good performances even in the least favorable case. The min-ent method sets a benchmark for optimal dynamic tournaments design.

  6. The limiting distribution of extremal exchange rate yields

    NARCIS (Netherlands)

    M.C.A.B. Hols (Martien); C.G. de Vries (Casper)

    1991-01-01

    textabstractSeveral nonnested fat-tailed distributions have been advocated for modelling exchange rate returns. Instead of directly estimating these nonnested distributions we investigate the extremal distribution of the returns. The advantage is that the parameter which characterizes the amount of

  7. Brownian limits, local limits, extreme value and variance asymptotics for convex hulls in the ball

    CERN Document Server

    Calka, Pierre; Yukich, J E

    2009-01-01

    The paper of Schreiber and Yukich [40] establishes an asymptotic representation for random convex polytope geometry in the unit ball $\\B_d, d \\geq 2,$ in terms of the general theory of stabilizing functionals of Poisson point processes as well as in terms of the so-called generalized paraboloid growth process. This paper further exploits this connection, introducing also a dual object termed the paraboloid hull process. Via these growth processes we establish local functional and measure-level limit theorems for the properly scaled radius-vector and support functions as well as for curvature measures and $k$-face empirical measures of convex polytopes generated by high density Poisson samples. We use general techniques of stabilization theory to establish Brownian sheet limits for the defect volume and mean width functionals, and we provide explicit variance asymptotics and central limit theorems for the $k$-face and intrinsic volume functionals. We establish extreme value theorems for radius-vector and suppo...

  8. Success stories in genomic medicine from resource-limited countries.

    Science.gov (United States)

    Mitropoulos, Konstantinos; Al Jaibeji, Hayat; Forero, Diego A; Laissue, Paul; Wonkam, Ambroise; Lopez-Correa, Catalina; Mohamed, Zahurin; Chantratita, Wasun; Lee, Ming Ta Michael; Llerena, Adrian; Brand, Angela; Ali, Bassam R; Patrinos, George P

    2015-06-18

    In recent years, the translation of genomic discoveries into mainstream medical practice and public health has gained momentum, facilitated by the advent of new technologies. However, there are often major discrepancies in the pace of implementation of genomic medicine between developed and developing/resource-limited countries. The main reason does not only lie in the limitation of resources but also in the slow pace of adoption of the new findings and the poor understanding of the potential that this new discipline offers to rationalize medical diagnosis and treatment. Here, we present and critically discuss examples from the successful implementation of genomic medicine in resource-limited countries, focusing on pharmacogenomics, genome informatics, and public health genomics, emphasizing in the latter case genomic education, stakeholder analysis, and economics in pharmacogenomics. These examples can be considered as model cases and be readily replicated for the wide implementation of pharmacogenomics and genomic medicine in other resource-limited environments.

  9. Tuberculosis diagnosis in resource-limited settings: Clinical use of ...

    African Journals Online (AJOL)

    EB

    In resource-limited settings, GeneXpert has been used ... had several visits to various lower level health centres and two admissions in a tertiary care hospital; however, the diagnosis .... point of view, implementation of GeneXpert testing.

  10. Student-Centered Teaching in Large Classes with Limited Resources

    Science.gov (United States)

    Renaud, Susan; Tannenbaum, Elizabeth; Stantial, Phillip

    2007-01-01

    The authors shares suggestions for instructors who teach large classes (from 50-80 students) with minimal resources. The challenges of managing the classroom, using pair and group work effectively, and working with limited resources are addressed. The authors suggests ways to take attendance quickly, to reduce written work to grade, to start and…

  11. Diagnostics in Ebola Virus Disease in Resource-Rich and Resource-Limited Settings.

    Directory of Open Access Journals (Sweden)

    Robert J Shorten

    2016-10-01

    Full Text Available The Ebola virus disease (EVD outbreak in West Africa was unprecedented in scale and location. Limited access to both diagnostic and supportive pathology assays in both resource-rich and resource-limited settings had a detrimental effect on the identification and isolation of cases as well as individual patient management. Limited access to such assays in resource-rich settings resulted in delays in differentiating EVD from other illnesses in returning travellers, in turn utilising valuable resources until a diagnosis could be made. This had a much greater impact in West Africa, where it contributed to the initial failure to contain the outbreak. This review explores diagnostic assays of use in EVD in both resource-rich and resource-limited settings, including their respective limitations, and some novel assays and approaches that may be of use in future outbreaks.

  12. Mental training affects distribution of limited brain resources.

    Directory of Open Access Journals (Sweden)

    Heleen A Slagter

    2007-06-01

    Full Text Available The information processing capacity of the human mind is limited, as is evidenced by the so-called "attentional-blink" deficit: When two targets (T1 and T2 embedded in a rapid stream of events are presented in close temporal proximity, the second target is often not seen. This deficit is believed to result from competition between the two targets for limited attentional resources. Here we show, using performance in an attentional-blink task and scalp-recorded brain potentials, that meditation, or mental training, affects the distribution of limited brain resources. Three months of intensive mental training resulted in a smaller attentional blink and reduced brain-resource allocation to the first target, as reflected by a smaller T1-elicited P3b, a brain-potential index of resource allocation. Furthermore, those individuals that showed the largest decrease in brain-resource allocation to T1 generally showed the greatest reduction in attentional-blink size. These observations provide novel support for the view that the ability to accurately identify T2 depends upon the efficient deployment of resources to T1. The results also demonstrate that mental training can result in increased control over the distribution of limited brain resources. Our study supports the idea that plasticity in brain and mental function exists throughout life and illustrates the usefulness of systematic mental training in the study of the human mind.

  13. Mental training affects distribution of limited brain resources.

    Science.gov (United States)

    Slagter, Heleen A; Lutz, Antoine; Greischar, Lawrence L; Francis, Andrew D; Nieuwenhuis, Sander; Davis, James M; Davidson, Richard J

    2007-06-01

    The information processing capacity of the human mind is limited, as is evidenced by the so-called "attentional-blink" deficit: When two targets (T1 and T2) embedded in a rapid stream of events are presented in close temporal proximity, the second target is often not seen. This deficit is believed to result from competition between the two targets for limited attentional resources. Here we show, using performance in an attentional-blink task and scalp-recorded brain potentials, that meditation, or mental training, affects the distribution of limited brain resources. Three months of intensive mental training resulted in a smaller attentional blink and reduced brain-resource allocation to the first target, as reflected by a smaller T1-elicited P3b, a brain-potential index of resource allocation. Furthermore, those individuals that showed the largest decrease in brain-resource allocation to T1 generally showed the greatest reduction in attentional-blink size. These observations provide novel support for the view that the ability to accurately identify T2 depends upon the efficient deployment of resources to T1. The results also demonstrate that mental training can result in increased control over the distribution of limited brain resources. Our study supports the idea that plasticity in brain and mental function exists throughout life and illustrates the usefulness of systematic mental training in the study of the human mind.

  14. Experimental evidence for extreme dispersal limitation in tropical forest birds.

    Science.gov (United States)

    Moore, R P; Robinson, W D; Lovette, I J; Robinson, T R

    2008-09-01

    Movements of organisms between habitat remnants can affect metapopulation structure, community assembly dynamics, gene flow and conservation strategy. In the tropical landscapes that support the majority of global biodiversity and where forest fragmentation is accelerating, there is particular urgency to understand how dispersal across habitats mediates the demography, distribution and differentiation of organisms. By employing unique dispersal challenge experiments coupled with exhaustive inventories of birds in a Panamanian lacustrine archipelago, we show that the ability to fly even short distances (birds, and that this variation correlates strongly with species' extinction histories and current distributions across the archipelago. This extreme variation in flight capability indicates that species' persistence in isolated forest remnants will be differentially mediated by their respective dispersal abilities, and that corridors connecting such fragments will be essential for the maintenance of avian diversity in fragmented tropical landscapes.

  15. Crossing the quality chasm in resource-limited settings.

    Science.gov (United States)

    Maru, Duncan Smith-Rohrberg; Andrews, Jason; Schwarz, Dan; Schwarz, Ryan; Acharya, Bibhav; Ramaiya, Astha; Karelas, Gregory; Rajbhandari, Ruma; Mate, Kedar; Shilpakar, Sona

    2012-11-30

    Over the last decade, extensive scientific and policy innovations have begun to reduce the "quality chasm"--the gulf between best practices and actual implementation that exists in resource-rich medical settings. While limited data exist, this chasm is likely to be equally acute and deadly in resource-limited areas. While health systems have begun to be scaled up in impoverished areas, scale-up is just the foundation necessary to deliver effective healthcare to the poor. This perspective piece describes a vision for a global quality improvement movement in resource-limited areas. The following action items are a first step toward achieving this vision: 1) revise global health investment mechanisms to value quality; 2) enhance human resources for improving health systems quality; 3) scale up data capacity; 4) deepen community accountability and engagement initiatives; 5) implement evidence-based quality improvement programs; 6) develop an implementation science research agenda.

  16. Crossing the quality chasm in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Maru Duncan

    2012-11-01

    Full Text Available Abstract Over the last decade, extensive scientific and policy innovations have begun to reduce the “quality chasm” - the gulf between best practices and actual implementation that exists in resource-rich medical settings. While limited data exist, this chasm is likely to be equally acute and deadly in resource-limited areas. While health systems have begun to be scaled up in impoverished areas, scale-up is just the foundation necessary to deliver effective healthcare to the poor. This perspective piece describes a vision for a global quality improvement movement in resource-limited areas. The following action items are a first step toward achieving this vision: 1 revise global health investment mechanisms to value quality; 2 enhance human resources for improving health systems quality; 3 scale up data capacity; 4 deepen community accountability and engagement initiatives; 5 implement evidence-based quality improvement programs; 6 develop an implementation science research agenda.

  17. Optimal vaccination policies for an SIR model with limited resources.

    Science.gov (United States)

    Zhou, Yinggao; Yang, Kuan; Zhou, Kai; Liang, Yiting

    2014-06-01

    The purpose of the paper is to use analytical method and optimization tool to suggest a vaccination program intensity for a basic SIR epidemic model with limited resources for vaccination. We show that there are two different scenarios for optimal vaccination strategies, and obtain analytical solutions for the optimal control problem that minimizes the total cost of disease under the assumption of daily vaccine supply being limited. These solutions and their corresponding optimal control policies are derived explicitly in terms of initial conditions, model parameters and resources for vaccination. With sufficient resources, the optimal control strategy is the normal Bang-Bang control. However, with limited resources, the optimal control strategy requires to switch to time-variant vaccination.

  18. Extreme diffusion limited electropolishing of niobium radiofrequency cavities

    CERN Document Server

    Crawford, Anthony C

    2016-01-01

    Deeply modulated, continuous, diffusion-limited current waveforms for electropolishing niobium single-cell elliptical radiofrequency cavities are reliably and repeatedly achieved at Fermilab. Details of the technique and cavity test results are reported here. The method is applicable for cavity frequencies in the range 500MHz to 3.9 GHz and can be extended to multicell structures.

  19. Studies on Actinomycetal Resources under Extreme Environments in the West of China

    Science.gov (United States)

    Li, W.

    2005-12-01

    s: Actinomycetes play a quite important role in natural ecological system and they are also profile producers of antibiotics, antitumor agents, enzymes, enzyme inhibitors and immunomodifiers. which have been widely applied in industry, agriculture, forestry and pharmaceutical industry. In the past, the research work on actinomycetes was mainly concentrated on that of common habitats. Actinomycetes resources under extreme environments (including extreme high and low temperature, extreme high or low pH, high salt concentration etc.) have received comparatively little attention from microbiologists. Actinomycetes are regarded as one kind of sideline microorganisms and those under extreme environments are better materials for biological evolution and phylogenetic development in research. There are much more unknown species and much more worth researching for actinomycetes under extreme environments. There are many extreme environmental resources in the west of China. For example, wide range snow-mountains, basified soil and lakes, widely distributed acid and alkaline hot-springs in Yunnan provinces; more than 73.3 million hektares basified soil and salt lakes in Xinjiang Province and many unusual environments in Qinghai Province and other western Provinces. They were mostly precious natural resources and were destroyed, relatively fewer can provided us with unique conditions for study on actinomycetal resources under extreme environments. In recent years, our main work was focusing on study of extremophilic actinomycetal resources in the west of China by using conventional cultivation-methods and culture-independent methods (PCR-clone and DGGE/TGGE, etc), Results showed that large amount of unknown microbial resources (including actinomycetal resources) existed in natural extreme environments. Additionally, lots of new taxa were isolated and characterized using a polyphasic approach. Further, we got some new compounds with different bioactivities from these

  20. Unified limiting form of graviton radiation at extreme energies

    CERN Document Server

    Ciafaloni, Marcello; Coradeschi, Francesco; Veneziano, Gabriele

    2016-01-01

    We derive the limiting form of graviton radiation in gravitational scattering at transplanckian energies ($E\\gg M_P$) and small deflection angles. We show that --- owing to the graviton's spin 2 --- such limiting form unifies the soft- and Regge- regimes of emission, by covering a broad angular range, from forward fragmentation to deeply central region. The single-exchange emission amplitudes have a nice expression in terms of the transformation phases of helicity amplitudes under rotations. As a result, the multiple-exchange emission amplitudes can be resummed via an impact parameter $b$-space factorization theorem that takes into account all coherence effects. We then see the emergence of an energy spectrum of the emitted radiation which, being tuned on $\\hbar/R \\sim M_P^2/E \\ll M_P$, is reminiscent of Hawking's radiation. Such a spectrum is much softer than the one na\\"ively expected for increasing input energies and neatly solves a potential energy crisis. Furthermore, by including rescattering correction...

  1. Weak limits for exploratory plots in the analysis of extremes

    CERN Document Server

    Das, Bikramjit

    2010-01-01

    Exploratory plotting tools have been devised aplenty in order to diagnose the goodness-of-fit of data sets to a hypothesized distribution. Some of them have found extensive use in diverse areas of finance, telecommunication, environmental science, etc. in order to detect sub-exponential or heavy-tailed behavior in observed data. In this paper we concentrate on two such plotting methodologies: the Quantile-Quantile plots for heavy-tails and the Mean Excess plots. Under the assumption of heavy-tailed behavior of the underlying sample the convergence in probability of these plots to a fixed set in a suitable topology of closed sets of $\\R^2$ has been studied in \\cite{das:resnick:2008} and \\cite{ghosh:resnick:2009}. These results give theoretical justifications for using the plots to test the null hypothesis that the underlying distribution is heavy-tailed by checking if the observed plot is ``close'' to the limit under the null hypothesis. In practice though one set of observations would lead to only one plot of...

  2. Resources, environment, and population: the nature of future limits.

    Science.gov (United States)

    Ridker, R G; Cecelski, E W

    1979-08-01

    The balance between world supplies of resources and the demands presented by population growth in the recent past, during the period to 2025, and for the long term is examined. Focus is on the issues, the past in terms of socioeconomic indicators, past trends in market places, and specific evidence of depletion; future demands in terms of population projections and growth in per capita demand; resource supplies to 2025; ultimate resource production possibilities; environmental constraints and risks (problems capable of control at reasonable cost, other domestic environmental problems, and potentially severe global problems); and implications. Improvement in socioeconomic indicators, relatively stable resource market prices, along with evidence of resource and environmental changes suggest that thus far the world as a whole has been able to win the race between demand and supply. For the next 50 years, during which a slowdown is projected in population growth rates and resource consumption, the most important problems to be faced are associated with the unequal distribution of resources and the transition problems of moving from 1 resource regime to another in an orderly fashion. For the long term, a projected equilibrium population of 10-12 billion can probably be sustained at a decent standard of living by more equitable distribution of food and shifts from less to more abundant resources. Ultimately, environmental and security problems associated with growing energy production and use such as increasing atmospheric levels of carbon dioxide and nuclear proliferation may be the most difficult to resolve. Although cessation of population growth would help, it does not by itself constitute a solution to the world's resource problems. Both the causes and the symptoms need to be worked on simultaneously. Understanding the true nature of the world's resource and environmental limitations is a 1st step in that direction.

  3. Soliciting Feedback from Resource Managers to Inform Response to Extreme Event Impact

    Science.gov (United States)

    Bedsworth, L. W.

    2014-12-01

    To date, extreme events have been defined by scientists through a top-down approach, relying on observations for current extremes and climate model projections based on future scenarios for their expected changes. These abstract definitions of extreme events are based on a corresponding characterization of what is "normal" and perhaps the choice of a threshold (e.g., a percentile of a historical distribution for a given climate variable), beyond which would represent an extreme event. However, there are not necessarily direct connections between these definitions and what is considered "extreme" in terms of impacts that challenge resource management. Several researchers have suggested that extreme event definitions would also be informed by input from on-the-ground resource managers who are familiar with the systems being impacted, the climate conditions that pose risks to those systems, and their resilience and adaptive capacity. This research will present preliminary survey work designed to solicit input from air and water quality managers in terms of what is considered an extreme event, how these events have been weathered in the past, and planned for in the future. The survey is based on literature review, interviews with air and water quality managers in California, and outreach to the scientific community. This work is the first step of a multistage research effort to link input from resource managers with scientific information to better inform air and water quality management and impacts of extreme events under a changing climate.

  4. Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development.

    Directory of Open Access Journals (Sweden)

    Raylea Rowbottom

    Full Text Available Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level. To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission.

  5. Therapeutic drug monitoring of nevirapine in resource-limited settings.

    NARCIS (Netherlands)

    L'homme, R.F.A.; Muro, E.P.; Droste, J.A.H.; Wolters, L.R.; Kolmer, NW van Ewijk-Benek; Schimana, W.; Burger, D.M.

    2008-01-01

    BACKGROUND: We developed a simple and inexpensive thin-layer chromatography (TLC) assay for semiquantitative detection of saliva concentrations of nevirapine in resource-limited settings. The method was validated in an African target population. METHODS: Paired plasma and saliva nevirapine concentra

  6. Therapeutic drug monitoring of nevirapine in resource-limited settings.

    NARCIS (Netherlands)

    L'homme, R.F.A.; Muro, E.P.; Droste, J.A.H.; Wolters, L.R.; Kolmer, NW van Ewijk-Benek; Schimana, W.; Burger, D.M.

    2008-01-01

    BACKGROUND: We developed a simple and inexpensive thin-layer chromatography (TLC) assay for semiquantitative detection of saliva concentrations of nevirapine in resource-limited settings. The method was validated in an African target population. METHODS: Paired plasma and saliva nevirapine concentra

  7. Food insecurity: limitations of emergency food resources for our patients.

    Science.gov (United States)

    Gany, Francesca; Bari, Sehrish; Crist, Michael; Moran, Alyssa; Rastogi, Natasha; Leng, Jennifer

    2013-06-01

    Rates of food insecurity are high among medically underserved patients. We analyzed food pantry responsiveness to the needs of medically ill cancer patients in New York City with the intent ofidentifying barriers to available food resources. Our data, collected from 60 pantries, suggest that the emergency food system is currently unable to accommodate patient needs. Accessibility issues include restricted service hours and documentation requirements. Food services were limited in quantity of food provided and the number of nutritious, palatable options. Additional emergency food resources and long-term approaches that provide ongoing food support to patients throughout their treatment period are needed.

  8. Antibiotic use and emerging resistance—how can resource-limited countries turn the tide?

    Science.gov (United States)

    Bebell, LM; Muiru, AN

    2015-01-01

    Antibiotic resistance is a global crisis driven by appropriate and inappropriate antibiotic use to treat human illness and promote animal growth. The antimicrobial resistance epidemic continues to spread due to the triple threat of unfettered access, minimal product regulation and oversight of antibiotic prescription, and lack of clinical diagnostic tools to support antibiotic de-escalation in low-resource settings. In high-resource settings, evidence-based strategies have improved appropriateness of antibiotic use, limiting the spread of drug-resistant organisms and reducing hospital-associated infections, which may also be effective to stop the spread of resistance in resource-poor countries. Current research and surveillance efforts on antimicrobial resistance and hospital-associated infections in low-resource settings are extremely limited, largely focused intensive care units. Many challenges exist to improving antibiotic use and infection control in resource-limited settings, and turning the tide requires intensifying research and surveillance, antimicrobial stewardship, and developing new bedside diagnostic tools for bacterial infections and antimicrobial susceptibility. PMID:25667187

  9. Antibiotic use and emerging resistance: how can resource-limited countries turn the tide?

    Science.gov (United States)

    Bebell, Lisa M; Muiru, Anthony N

    2014-09-01

    Antibiotic resistance is a global crisis driven by appropriate and inappropriate antibiotic use to treat human illness and promote animal growth. The antimicrobial resistance epidemic continues to spread due to the triple threat of unfettered access, minimal product regulation and oversight of antibiotic prescription, and lack of clinical diagnostic tools to support antibiotic de-escalation in low-resource settings. In high-resource settings, evidence-based strategies have improved the appropriateness of antibiotic use, limiting the spread of drug-resistant organisms and reducing hospital-associated infections, strategies which may also be effective to stop the spread of resistance in resource-poor countries. Current research and surveillance efforts on antimicrobial resistance and hospital-associated infections in low-resource settings are extremely limited and largely focused on intensive care units. Many challenges exist to improving antibiotic use and infection control in resource-limited settings, and turning the tide requires intensifying research and surveillance, antimicrobial stewardship, and developing new bedside diagnostic tools for bacterial infections and antimicrobial susceptibility.

  10. Food Insecurity: Limitations of Emergency Food Resources for Our Patients

    OpenAIRE

    Gany, Francesca; Bari, Sehrish; Crist, Michael; Moran, Alyssa; Rastogi, Natasha; Leng, Jennifer

    2012-01-01

    Rates of food insecurity are high among medically underserved patients. We analyzed food pantry responsiveness to the needs of medically ill cancer patients in New York City with the intent ofidentifying barriers to available food resources. Our data, collected from 60 pantries, suggest that the emergency food system is currently unable to accommodate patient needs. Accessibility issues include restricted service hours and documentation requirements. Food services were limited in quantity of ...

  11. Climate Change Extreme Events: Meeting the Information Needs of Water Resource Managers

    Science.gov (United States)

    Quay, R.; Garfin, G. M.; Dominguez, F.; Hirschboeck, K. K.; Woodhouse, C. A.; Guido, Z.; White, D. D.

    2013-12-01

    Information about climate has long been used by water managers to develop short term and long term plans and strategies for regional and local water resources. Inherent within longer term forecasts is an element of uncertainty, which is particularly evident in Global Climate model results for precipitation. For example in the southwest estimates in the flow of the Colorado River based on GCM results indicate changes from 120% or current flow to 60%. Many water resource managers are now using global climate model down scaled estimates results as indications of potential climate change as part of that planning. They are addressing the uncertainty within these estimates by using an anticipatory planning approach looking at a range of possible futures. One aspect of climate that is important for such planning are estimates of future extreme storm (short term) and drought (long term) events. However, the climate science of future possible changes in extreme events is less mature than general climate change science. At a recent workshop among climate scientists and water managers in the southwest, it was concluded the science of climate change extreme events is at least a decade away from being robust enough to be useful for water managers in their water resource management activities. However, it was proposed that there are existing estimates and records of past flooding and drought events that could be combined with general climate change science to create possible future events. These derived events could be of sufficient detail to be used by water resource managers until such time that the science of extreme events is able to provide more detailed estimates. Based on the results of this workshop and other work being done by the Decision Center for a Desert City at Arizona State University and the Climate Assessment for the Southwest center at University of Arizona., this article will 1) review what are the extreme event data needs of Water Resource Managers in the

  12. Ensuring Resilience of Natural Resources under Exposure to Extreme Climate Events

    OpenAIRE

    Brent Jacobs; Louise Boronyak-Vasco; Kristy Moyle; Peat Leith

    2016-01-01

    Natural resources directly support rural livelihoods and underpin much of the wealth of rural and regional Australia. Climate change manifesting as increasing frequency and or severity of extreme weather events poses a threat to sustainable management of natural resources because the recurrence of events may exceed the resilience of natural systems or the coping capacity of social systems. We report the findings of a series of participatory workshops with communities in eight discrete landsca...

  13. DETERMINATION OF THE TIME LIMITS OF ELIGIBILITY IN A STATE OF EXTREME NECESSITY

    Directory of Open Access Journals (Sweden)

    Vyacheslav Victorovich Naumov

    2015-12-01

    Full Text Available Up to now the limits of eligibility of extreme necessity were not the subject of independent research.The problems of definition of the time limits of p eligibility are considered in this article based on the scientific and monographic literature analysis. Relevance of the considered matter is defined by the fact that the correct establishment of time limits of eligibility of act is of great importance in the law enforcement activity in order to establish the non-delinquency of act in state of extreme necessity. The purpose of this research is the analysis of definition of time limits of extreme necessity eligibility and drawing proposals on this basis for improvement of legislative regulations and existing laws enforcement efficiency with regards to extreme necessity. Research methods: dialectic, formal-logical, system. The author empha-sizes the eligibility limits of admissible harm and the temporary limits. When determining the time limits the author emphasizes the following criteria: the value of danger, intensity of actions, and also identifies an "initial" and "final" moments in the defense of legally protected interests. The improvement of the existing legisla-tion was proposed based on the carried-out analysis.

  14. Habitat, not resource availability, limits consumer production in lake ecosystems

    Science.gov (United States)

    Craig, Nicola; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

    2015-01-01

    Food web productivity in lakes can be limited by dissolved organic carbon (DOC), which reduces fish production by limiting the abundance of their zoobenthic prey. We demonstrate that in a set of 10 small, north temperate lakes spanning a wide DOC gradient, these negative effects of high DOC concentrations on zoobenthos production are driven primarily by availability of warm, well-oxygenated habitat, rather than by light limitation of benthic primary production as previously proposed. There was no significant effect of benthic primary production on zoobenthos production after controlling for oxygen, even though stable isotope analysis indicated that zoobenthos do use this resource. Mean whole-lake zoobenthos production was lower in high-DOC lakes with reduced availability of oxygenated habitat, as was fish biomass. These insights improve understanding of lake food webs and inform management in the face of spatial variability and ongoing temporal change in lake DOC concentrations.

  15. Molecular oncology testing in resource-limited settings.

    Science.gov (United States)

    Gulley, Margaret L; Morgan, Douglas R

    2014-11-01

    Cancer prevalence and mortality are high in developing nations, where resources for cancer control are inadequate. Nearly one-quarter of cancers in resource-limited nations are infection related, and molecular assays can capitalize on this relationship by detecting pertinent pathogen genomes and human gene variants to identify those at highest risk for progression to cancer, to classify lesions, to predict effective therapy, and to monitor tumor burden over time. Prime examples are human papillomavirus in cervical neoplasia, Helicobacter pylori and Epstein-Barr virus in gastric adenocarcinoma and lymphoma, and hepatitis B or C virus in hepatocellular cancer. Research is underway to engineer devices that overcome social, economic, and technical barriers limiting effective laboratory support. Additional challenges include an educated workforce, infrastructure for quality metrics and record keeping, and funds to sustain molecular test services. The combination of well-designed interfaces, novel and robust electrochemical technology, and telemedicine tools will promote adoption by frontline providers. Fast turnaround is crucial for surmounting loss to follow-up, although increased use of cell phones, even in rural areas, enhances options for patient education and engagement. Links to a broadband network facilitate consultation and centralized storage of medical data. Molecular technology shows promise to address gaps in health care through rapid, user-friendly, and cost-effective devices reflecting clinical priorities in resource-poor areas.

  16. Modeling multiple resource limitation in tropical dry forests

    Science.gov (United States)

    Medvigy, D.; Xu, X.; Zarakas, C.

    2015-12-01

    Tropical dry forests (TDFs) are characterized by a long dry season when little rain falls. At the same time, many neotropical soils are highly weathered and relatively nutrient poor. Because TDFs are often subject to both water and nutrient constraints, the question of how they will respond to environmental perturbations is both complex and highly interesting. Models, our basic tools for projecting ecosystem responses to global change, can be used to address this question. However, few models have been specifically parameterized for TDFs. Here, we present a new version of the Ecosystem Demography 2 (ED2) model that includes a new parameterization of TDFs. In particular, we focus on the model's framework for representing limitation by multiple resources (carbon, water, nitrogen, and phosphorus). Plant functional types are represented in terms of a dichotomy between "acquisitive" and "conservative" resource acquisition strategies. Depending on their resource acquisition strategy and basic stoichiometry, plants can dynamically adjust their allocation to organs (leaves, stem, roots), symbionts (e.g. N2-fixing bacteria), and mycorrhizal fungi. Several case studies are used to investigate how resource acquisition strategies affect ecosystem responses to environmental perturbations. Results are described in terms of the basic setting (e.g., rich vs. poor soils; longer vs. shorter dry season), and well as the type and magnitude of environmental perturbation (e.g., changes in precipitation or temperature; changes in nitrogen deposition). Implications for ecosystem structure and functioning are discussed.

  17. Perinatal pathology: practice suggestions for limited-resource settings.

    Science.gov (United States)

    Roberts, Drucilla J

    2013-06-01

    The practice of perinatal pathology in much of the world suffers, as do all subspecialties of anatomic pathology, from inadequate resources (equipment, consumables, and both professional and technical personnel), from lack of education (not only of the pathologist but also of the clinicians responsible for sending the specimens, and the technicians processing the specimens), and from lack of appropriate government sector support. Perinatal pathology has significant public health-related utility and should be championing its service by providing maternal and fetal/infant mortality and morbidity data to governmental health ministries. It is with this pathologic data that informed decisions can be made on health-related courses of action and allocation of resources. These perinatal pathology data are needed to develop appropriate public health initiatives, specifically toward achieving the Millennium Developmental Goals as the best way to effectively decrease infant and maternal deaths and to determine causes of perinatal mortality and morbidity. The following overview will focus on the utility of perinatal pathology specifically as related to its public health function and will suggest methods to improve its service in resource-poor settings. This article is offered not as a critique of the current practice that most pathologists find themselves working in globally, but to provide suggestions for improving perinatal pathology services, which could be implemented with the limited available resources and manpower most pathology departments currently have. In addition, we offer suggestions for graded improvements ("ramping up") over time.

  18. Potential contributions of extremophiles to hydrocarbon resources in marine extreme environments:A review

    Institute of Scientific and Technical Information of China (English)

    WANG Jiasheng; WANG Yongbiao; LI Qing

    2007-01-01

    To understand the potential mechanism of marine extremophiles participating in the formation and the evolution of hydrocarbon resources in marine extreme environments,some typical kinds of extremophiles and their distributions in marine hydrothermal and cold vents are discussed and evaluated respectively.The potential relationship between extremophile activities and hydrocarbon resources in marine extreme environments are then discussed in details.It could be now preliminary concluded that archaea and bacteria are the two main kinds of extremophiles in marine extreme environments.The dominating microbe communities in hydrothermal vents are heterotrophic zymogens,sulfate reducers and methanogens,while the ANME-2 group(Methanosarcinales) surrounded by sulfate-reducing bacteria and ANME-1 group dominate in cold vents.Marine extremophiles would be able to use CH,and H2S to synthesize energy for metabolism and to support food chains for other unique macrobiota nearby,which together present a high abundance but a low diversity with distinct characteristics of horizontal and vertical distributions.Marine extremophiles might play an important role either directly or indirectly in the processes of hydrocarbon formation and subsequent alteration,and could indicate the evolution of hydrocarbon resources in marine extreme environments.Our research thus has a great significance both in theoretical approach of potential hydrocarbon resources formed by marine extremophile activities and in practical exploration of the potential hydrocarbonsource sedimentary layers formed in the Earth history or the potential strata in southern China.

  19. Physiological and life history strategies of a fossil large mammal in a resource-limited environment.

    Science.gov (United States)

    Köhler, Meike; Moyà-Solà, Salvador

    2009-12-01

    Because of their physiological and life history characteristics, mammals exploit adaptive zones unavailable to ectothermic reptiles. Yet, they perform best in energy-rich environments because their high and constant growth rates and their sustained levels of resting metabolism require continuous resource supply. In resource-limited ecosystems such as islands, therefore, reptiles frequently displace mammals because their slow and flexible growth rates and low metabolic rates permit them to operate effectively with low energy flow. An apparent contradiction of this general principle is the long-term persistence of certain fossil large mammals on energy-poor Mediterranean islands. The purpose of the present study is to uncover the developmental and physiological strategies that allowed fossil large mammals to cope with the low levels of resource supply that characterize insular ecosystems. Long-bone histology of Myotragus, a Plio-Pleistocene bovid from the Balearic Islands, reveals lamellar-zonal tissue throughout the cortex, a trait exclusive to ectothermic reptiles. The bone microstructure indicates that Myotragus grew unlike any other mammal but similar to crocodiles at slow and flexible rates, ceased growth periodically, and attained somatic maturity extremely late by approximately 12 years. This developmental pattern denotes that Myotragus, much like extant reptiles, synchronized its metabolic requirements with fluctuating resource levels. Our results suggest that developmental and physiological plasticity was crucial to the survival of this and, perhaps, other large mammals on resource-limited Mediterranean Islands, yet it eventually led to their extinction through a major predator, Homo sapiens.

  20. Central limit theorems for smoothed extreme value estimates of Poisson point processes boundaries

    CERN Document Server

    Girard, Stéphane

    2011-01-01

    In this paper, we give sufficient conditions to establish central limit theorems for boundary estimates of Poisson point processes. The considered estimates are obtained by smoothing some bias corrected extreme values of the point process. We show how the smoothing leads Gaussian asymptotic distributions and therefore pointwise confidence intervals. Some new unidimensional and multidimensional examples are provided.

  1. Ensuring Resilience of Natural Resources under Exposure to Extreme Climate Events

    Directory of Open Access Journals (Sweden)

    Brent Jacobs

    2016-06-01

    Full Text Available Natural resources directly support rural livelihoods and underpin much of the wealth of rural and regional Australia. Climate change manifesting as increasing frequency and or severity of extreme weather events poses a threat to sustainable management of natural resources because the recurrence of events may exceed the resilience of natural systems or the coping capacity of social systems. We report the findings of a series of participatory workshops with communities in eight discrete landscapes in South East New South Wales, Australia. The workshops focused on how natural resource management (NRM is considered in the Prevent-Prepare-Respond-Recover emergency management cycle. We found that NRM is generally considered only in relation to the protection of life and property and not for the intrinsic value of ecosystem services that support communities. We make three recommendations to improve NRM under extreme climate events. Firstly, the support to communities offered by emergency management agencies could be bolstered by guidance material co-produced with government NR agencies. Secondly, financial assistance from government should specifically target the restoration and maintenance of green infrastructure to avoid loss of social-ecological resilience. Thirdly, action by natural resource dependent communities should be encouraged and supported to better protect ecosystem services in preparation for future extreme events.

  2. Memory and self-induced shocks in an evolutionary population competing for limited resources.

    Science.gov (United States)

    Kay, Roland; Johnson, Neil F

    2004-11-01

    We present a detailed discussion of the role played by memory, and the nature of self-induced shocks, in an evolutionary population competing for limited resources. Our study builds on a previously introduced multiagent system [Phys. Rev. Lett. 82, 3360 (1999)] which has attracted significant attention in the literature. This system exhibits self-segregation of the population based on the "gene" value p (where 0resource level, and self-induced large changes which spontaneously arise as the dynamical system evolves. We find that the large, macroscopic self-induced shocks that arise are controlled by microscopic changes within extreme subgroups of the population (i.e., subgroups with "gene" values p approximately 0 and p approximately 1).

  3. Integrated Yard Space Allocation and Yard Crane Deployment Problem in Resource-Limited Container Terminals

    Directory of Open Access Journals (Sweden)

    Caimao Tan

    2016-01-01

    Full Text Available Yard storage space and yard crane equipment are the core resources in the container terminal yard area. This paper studies the integrated yard space allocation (outbound container space and yard crane deployment problem in resource-limited container terminals where yard space and yard cranes are extremely scarce. Two corresponding counterstrategies are introduced, respectively, and the integrated problem is solved as mixed integer programming. The model this paper formulated considers the container volume fluctuation of the service line, and the objective is a trade-off between yard sharing space and terminal operation cost. In numerical experiments, this paper tries to reveal the management meaning in practical operation of container terminal and provides decision support for terminal managers; therefore a series of scenarios are presented to analyze the relations among the yard sharing space, the number of yard cranes, the size of yard subblock, and the cost of terminal operation.

  4. Extreme field limits in the interaction of laser light with ultrarelativistic electrons

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S. V.; Esirkepov, T. Zh.; Hayashi, Y.; Kando, M.; Kiriyama, H.; Koga, J.; Kondo, K.; Kotaki, H.; Pirozhkov, A.; Bulanov, S. S.; Zhidkov, A.; Chen, P.; Neely, D.; Kato, Y.; Narozhny, N. B.; Korn, G. [Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); University of California, Berkeley, CA 94720 (United States); Osaka University, Osaka 565-0871 (Japan); National Taiwan University, Taipei 10617, Taiwan (China); Central Laser Facility, STFC, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka 431-1202 (Japan); Moscow Engineering Physics Institute (State University), Moscow 115409 (Russian Federation); Max-Planck-Institut fuer Quantenoptik, Garching 85748 (Germany) and ELI Beamline Facility, Institute of Physics, CAS, Prague 18221 (Czech Republic)

    2012-07-11

    The critical electric field of quantum electrodynamics is so strong that it produces electron-positron pairs from vacuum, converting the energy of light into matter. This field has become feasible through the construction of extremely high power lasers or/and with the sophisticated use of nonlinear processes in relativistic plasmas. A feasibility of the experiments on the collision of laser light and high intensity electromagnetic pulses, generated by relativistic flying mirrors, with relativistic electrons for the studying of extreme field limits in the nonlinear interaction of electromagnetic waves is discussed.

  5. Dismounted complex blast injuries: patterns of injuries and resource utilization associated with the multiple extremity amputee.

    Science.gov (United States)

    Fleming, Mark; Waterman, Scott; Dunne, James; D'Alleyrand, Jean-Claude; Andersen, Romney C

    2012-01-01

    The objective of this report is to analyze the resource utilization and injury patterns of complex dismounted blast injuries. A retrospective review of U.S. service members injured in combat between 2007 and 2010 was conducted. Data analyzed included age, injury mechanism, amputated limbs, number and type of associated injuries, blood products utilized, intensive care unit length of stay (ILOS), hospital length of stay (HLOS) and the Injury Severity Score (ISS). Patients were stratified based on the number of amputations. Sixty-three patients comprised the multiple extremity amputation (MEA) group. Ninety-eight percent sustained injuries from an improvised explosive device (IED) and 96% were dismounted. The ISS, number of surgical encounters, blood products utilized and ILOS were all clinically significantly different than controls. Care of multiple extremity amputees involves the utilization of significant resources. This knowledge may better help surgeons and administrators allocate assets at hospitals, both military and civilian, who care for this complex and challenging patient population.

  6. Exploring knowledge about microbes living in the extreme environments – the resources review

    Directory of Open Access Journals (Sweden)

    Urszula K. Czyżewska

    2011-06-01

    Full Text Available Extremophiles are organisms that tolerate or require to live the extreme ranges of variation ofthe environmental factors such as temperature, pH, salinity, concentrations of heavy metals, highhydrostatic pressure, ionizing radiation, ultraviolet, availability of water, light, oxygen, and nutritionallylimited environments, etc. Exposure to such diverse factors caused, in the light of evolutionary changes,the appearence of many biochemical adaptations. In most cases, extremophiles are unicellular organismsbelonging to the Archaea domain, but there are also representatives of other domains (Bacteria,Eucaryota and multicellular organisms. The diversity of the Internet resources and printed materials(scientific publications reflect areas of this interest. Special characteristics of extremophiles are ofinterest to researchers in various fields of biological sciences (astrobiology, ecology, biotechnology,biospeleology. The purpose of this article is to review the most representative resources aboutmicroorganisms living in extreme environments and indicate the directions of the future research.

  7. Caring for the injured child in settings of limited resource.

    Science.gov (United States)

    Stephenson, Jacob

    2016-02-01

    Children represent the most vulnerable members of our global society, a truth that is magnified when they are physically wounded. In much of the developed world, society has responded by offering protection in the form of law, injury prevention guidelines, and effective trauma systems to provide care for the injured child. Much of our world, though, remains afflicted by poverty and a lack of protective measures. As the globe becomes smaller by way of ease of travel and technology, surgeons are increasingly able to meet these children where they live and in doing so offer their hands and voices to care and protect these young ones. This article is intended as an overview of current issues in pediatric trauma care in the developing world as well as to offer some tips for the volunteer surgeon who may be involved in the care of the injured child in a setting of limited resource availability. Published by Elsevier Inc.

  8. Optimal Watermark Embedding and Detection Strategies Under Limited Detection Resources

    CERN Document Server

    Merhav, Neri

    2007-01-01

    An information-theoretic approach is proposed to watermark embedding and detection under limited detector resources. First, we consider the attack-free scenario under which asymptotically optimal decision regions in the Neyman-Pearson sense are proposed, along with the optimal embedding rule. Later, we explore the case of zero-mean i.i.d. Gaussian covertext distribution with unknown variance under the attack-free scenario. For this case, we propose a lower bound on the exponential decay rate of the false-negative probability and prove that the optimal embedding and detecting strategy is superior to the customary linear, additive embedding strategy in the exponential sense. Finally, these results are extended to the case of memoryless attacks and general worst case attacks. Optimal decision regions and embedding rules are offered, and the worst attack channel is identified.

  9. Resource Limitation, Tolerance, and the Future of Ecological Plant Classification

    Directory of Open Access Journals (Sweden)

    Joseph M Craine

    2012-10-01

    Full Text Available Throughout the evolutionary history of plants, drought, shade, and scarcity of nutrients have structured ecosystems and communities globally. Humans have begun to drastically alter the prevalence of these environmental factors with untold consequences for plant communities and ecosystems worldwide. Given limitations in using organ-level traits to predict ecological performance of species, recent advances using tolerances of low resource availability as plant functional traits are revealing the often hidden roles these factors have in structuring communities and are becoming central to classifying plants ecologically. For example, measuring the physiological drought tolerance of plants has increased the predictability of differences among species in their ability to survive drought as well as the distribution of species within and among ecosystems. Quantifying the shade tolerance of species has improved our understanding of local and regional species diversity and how species have sorted within and among regions. As the stresses on ecosystems continue to shift, coordinated studies of whole-plant growth centered on tolerance of low resource availability will be central in predicting future ecosystem functioning and biodiversity. This will require efforts that quantify tolerances for large numbers of species and develop bioinformatic and other techniques for comparing large number of species.

  10. Resource limitation, tolerance, and the future of ecological plant classification.

    Science.gov (United States)

    Craine, Joseph M; Engelbrecht, Bettina M J; Lusk, Christopher H; McDowell, Nate G; Poorter, Hendrik

    2012-01-01

    Throughout the evolutionary history of plants, drought, shade, and scarcity of nutrients have structured ecosystems and communities globally. Humans have begun to drastically alter the prevalence of these environmental factors with untold consequences for plant communities and ecosystems worldwide. Given limitations in using organ-level traits to predict ecological performance of species, recent advances using tolerances of low resource availability as plant functional traits are revealing the often hidden roles these factors have in structuring communities and are becoming central to classifying plants ecologically. For example, measuring the physiological drought tolerance of plants has increased the predictability of differences among species in their ability to survive drought as well as the distribution of species within and among ecosystems. Quantifying the shade tolerance of species has improved our understanding of local and regional species diversity and how species have sorted within and among regions. As the stresses on ecosystems continue to shift, coordinated studies of whole-plant growth centered on tolerance of low resource availability will be central in predicting future ecosystem functioning and biodiversity. This will require efforts that quantify tolerances for large numbers of species and develop bioinformatic and other techniques for comparing large number of species.

  11. Thermodynamic Properties of Gaseous Plasmas in the Limit of Extremely Low Temperature

    CERN Document Server

    Iosilevskiy, Igor

    2010-01-01

    Limiting structure of thermodynamic functions of gaseous plasmas is under consideration in the limit of zero temperature and density. Remarkable tendency, which was claimed previously (Iosilevskiy and Gryaznov, 1985) is carried to extreme. Both equations of state, thermal and caloric ones obtain in this limit identical stepped structure ("ionization stairs") for plasma of any single element when this limit (T -> 0, n -> 0) is carried out at fixed value of chemical potential for electrons (or atoms). The same stepped structure is valid for plasma of mixtures or compounds. This structure appears within a fixed (negative) range of chemical potential of electrons bounded below by value of major ionization potential of element and above by the value depending on sublimation energy of substance. Binding energies of all possible bound complexes (atomic, molecular, ionic and clusters) in its ground state are the only quantities that manifest itself in meaningful details of this limiting picture as location and value ...

  12. Effective one-dimensionality of universal ac hopping conduction in the extreme disorder limit

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Schrøder, Thomas

    1996-01-01

    A phenomenological picture of ac hopping in the symmetric hopping model (regular lattice, equal site energies, random energy barriers) is proposed according to which conduction in the extreme disorder limit is dominated by essentially one-dimensional "percolation paths." Modeling a percolation path...... as strictly one dimensional with a sharp jump rate cutoff leads to an expression for the universal ac conductivity that fits computer simulations in two and three dimensions better than the effective medium approximation....

  13. Limited Resources, Limited Opportunities, and the Accumulation of Disadvantage: Evidence from the Global Survey of Physicists

    Science.gov (United States)

    Ivie, Rachel

    2012-03-01

    Using the results of the Global Survey of Physicists, which we conducted in collaboration with the International Union of Pure and Applied Physics Working Group on Women, we document the effect of limited resources and opportunities on women physicists' careers. We find that women respondents are less likely than men to report access to a variety of resources and opportunities that would be helpful in advancing a scientific career. These include access to funding, travel money, lab and office space, equipment, clerical support, and availability of employees or students to help with research. When asked about specific opportunities, women report fewer invited talks and overseas research opportunities. Women who responded are less likely to have been journal editors, acted as bosses or managers, advised graduate students, served on thesis or dissertation committees, and served on committees for grant agencies. We also show the disproportionate effects of children on women physicists' careers. Women who responded are more likely than men to have changed their work situations upon becoming parents. Mothers are more likely than men and women without children to report that their careers have progressed more slowly than colleagues who finished their degrees at the same time. Furthermore, women are more likely than men to report that their careers affected the decisions they made about marriage and children. The results of this survey draw attention to the need to focus on factors other than representation when discussing the situation of women in physics. 15,000 physicists in 130 countries answered this survey, and across all these countries, women have fewer resources and opportunities and are more affected by cultural expectations concerning child care. Cultural expectations about home and family are difficult to change. However, for women to have successful outcomes and advance in physics, they must have equal access to resources and opportunities.

  14. Know your limits? Climate extremes impact the range of Scots pine in unexpected places.

    Science.gov (United States)

    Julio Camarero, J; Gazol, Antonio; Sancho-Benages, Santiago; Sangüesa-Barreda, Gabriel

    2015-11-01

    Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin ('rear edge') of species distributional ranges, has received little attention. The aim of this study was to examine the impact of one such extreme cold event on a population of Scots pine (Pinus sylvestris) along the species' European southern rear-edge range limit and to determine how such events can be incorporated into species distribution models (SDMs). A combination of dendrochronology and field observation was used to quantify how an extreme cold event in 2001 in eastern Spain affected growth, needle loss and mortality of Scots pine. Long-term European climatic data sets were used to contextualize the severity of the 2001 event, and an SDM for Scots pine in Europe was used to predict climatic range limits. The 2001 winter reached record minimum temperatures (equivalent to the maximum European-wide diurnal ranges) and, for trees already stressed by a preceding dry summer and autumn, this caused dieback and large-scale mortality. Needle loss and mortality were particularly evident in south-facing sites, where post-event recovery was greatly reduced. The SDM predicted European Scots pine distribution mainly on the basis of responses to maximum and minimum monthly temperatures, but in comparison with this the observed effects of the 2001 cold event at the southerly edge of the range limit were unforeseen. The results suggest that in order to better forecast how anthropogenic climate change might affect future forest distributions, distribution modelling techniques such as SDMs must incorporate climatic extremes. For Scots pine, this study shows that the effects of cold extremes should be included across the entire distribution margin, including the southern 'rear edge', in order to avoid biased predictions based solely on warmer climatic scenarios. © The Author 2015. Published by

  15. Direct competition results from strong competiton for limited resource

    CERN Document Server

    Mirrahimi, Sepideh; Wakano, Joe Yuichiro

    2012-01-01

    We study a model of competition for resource through a chemostat-type model where species consume the common resource that is constantly supplied. We assume that the species and resources are characterized by a continuous trait. As already proved, this model, although more complicated than the usual Lotka-Volterra direct competition model, describes competitive interactions leading to concentrated distributions of species in continuous trait space. Here we assume a very fast dynamics for the supply of the resource and a fast dynamics for death and uptake rates. In this regime we show that factors that are independent of the resource competition become as important as the competition efficiency and that the direct competition model is a good approximation of the chemostat. This is performed through asymptotic analysis, introducing different scales for the resource renewal rate and the uptake rate. The mathematical difficulty relies in a possible initial layer for the resource dynamics. The chemostat model come...

  16. Risk-based water resources planning: Coupling water allocation and water quality management under extreme droughts

    Science.gov (United States)

    Mortazavi-Naeini, M.; Bussi, G.; Hall, J. W.; Whitehead, P. G.

    2016-12-01

    The main aim of water companies is to have a reliable and safe water supply system. To fulfil their duty the water companies have to consider both water quality and quantity issues and challenges. Climate change and population growth will have an impact on water resources both in terms of available water and river water quality. Traditionally, a distinct separation between water quality and abstraction has existed. However, water quality can be a bottleneck in a system since water treatment works can only treat water if it meets certain standards. For instance, high turbidity and large phytoplankton content can increase sharply the cost of treatment or even make river water unfit for human consumption purposes. It is vital for water companies to be able to characterise the quantity and quality of water under extreme weather events and to consider the occurrence of eventual periods when water abstraction has to cease due to water quality constraints. This will give them opportunity to decide on water resource planning and potential changes to reduce the system failure risk. We present a risk-based approach for incorporating extreme events, based on future climate change scenarios from a large ensemble of climate model realisations, into integrated water resources model through combined use of water allocation (WATHNET) and water quality (INCA) models. The annual frequency of imposed restrictions on demand is considered as measure of reliability. We tested our approach on Thames region, in the UK, with 100 extreme events. The results show increase in frequency of imposed restrictions when water quality constraints were considered. This indicates importance of considering water quality issues in drought management plans.

  17. Lethal combat over limited resources: testing the importance of competitors and kin.

    Science.gov (United States)

    Innocent, Tabitha M; West, Stuart A; Sanderson, Jennifer L; Hyrkkanen, Nita; Reece, Sarah E

    2011-09-01

    Although most animals employ strategies to avoid costly escalation of conflict, the limitation of critical resources may lead to extreme contests and fatal fighting. Evolutionary theories predict that the occurrence and intensity of fights can be explained by resource value and the density and relatedness of competitors. However, the interaction between these factors and their relative importance often remains unclear; moreover, few systems allow all variables to be experimentally investigated, making tests of these theoretical predictions rare. Here, we use the parasitoid wasp Melittobia to test the importance of all these factors. In contrast to predictions, variation in contested resource value (female mates) and the relatedness of competitors do not influence levels of aggression. However, as predicted, fight intensity increased with competitor density and was not influenced by the greater cost of fighting at high density. Our results suggest that in the absence of kin recognition, indirectly altruistic behavior (spite) is unlikely to evolve, and in such circumstances, the scale of competition will strongly influence the amount of kin discrimination in the form of level of aggression as observed in Melittobia species.

  18. Special Needs of Young Women with Breast Cancer in Limited Resource Settings.

    Science.gov (United States)

    Gálvez-Hernández, Carmen Lizette; González-Robledo, María Cecilia; Barragán-Carrillo, Regina; Villarreal-Garza, Cynthia

    2017-01-01

    Young women with breast cancer (YWBC) comprise a group of patients with unique biopsychosocial characteristics with a special perception of needs throughout their disease and survivorship. Contexts marked by restricted allocations and economic constraints might further aggravate the struggle of these patients living within limited resource settings and can demand added requirements for them and their families. To analytically explore the existing knowledge regarding the needs of YWBC in low- and middle- income countries (LMICs). We conducted a thorough literature review of scientific journal databases available in Spanish and English containing information on YWBC in LMICs. We did not find any publications exclusively assessing this topic in resource-limited settings. We looked for data on the different types of YW need from studies in the region that assessed the needs of breast cancer (BC) patients in general and described in their findings the particularities of young patients. Young BC patients described within the literature present a variety of needs. Those reported most frequently as unmet were related to information needs and psychological counseling, practical and physical assistance, and social and spiritual support. Published literature on the subject - particularly in Latin America - is extremely scarce. This offers an area of opportunity for conducting further research in this topic that would help improve health professional training and establish health policies in favor of YWBC.

  19. Perturbative effects of spinning black holes in the extreme mass-ratio limit

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Hiroyuki; Campanelli, Manuela; Lousto, Carlos O; Zlochower, Yosef, E-mail: nakano@astro.rit.edu, E-mail: manuela@astro.rit.edu, E-mail: lousto@astro.rit.edu, E-mail: yosef@astro.rit.edu [Center for Computational Relativity and Gravitation, School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY 14623 (United States)

    2011-07-07

    Recently, we proposed an enhancement of the Regge-Wheeler-Zerilli formalism for first-order perturbations about a Schwarzschild background that includes first-order corrections due to the background black-hole spin in the black-hole perturbation approach. Using this formalism, we analytically investigate gravitational wave emission and linear momentum flux from a head-on collision of two spinning black holes in the extreme mass-ratio limit. The result derived in the lowest slow-motion and weak-field approximations here is consistent with the post-Newtonian calculation.

  20. Limits of UK Counterterrorism Policy and its Implications for Islamophobia and Far Right Extremism

    Directory of Open Access Journals (Sweden)

    Tahir Abbas

    2015-10-01

    Full Text Available The UK Government has recently announced a new Counter-Terrorism and Security Act 2015 to facilitate tackling the threat of violent extremism. In light of this and previous initiatives, this paper provides a critical assessment of UK counterterrorism policy. This policy has created a notion of ‘suspect communities’ such that it has alienated young Muslims at the community engagement level, conceivably and empirically, potentially further exacerbating concerns government and communities have over questions of radicalisation, extremism, and the associated political and criminal violence. This paper argues that such policies can lead to the institutionalisation of Islamophobia, acting as an echo chamber for far right extremism to flourish. Significant gaps in government policy in this area can only be addressed by fostering effective relations between communities and policy makers, with enablers such as police officers, youth workers, activists and faith leaders empowered to formulate nuanced approaches in various local area settings. Given the social, cultural and political situation regarding British Muslim youth, including those presently thought to be fighting in parts of Iraq and Syria, as well as ongoing threats on UK soil presented as imminent and dangerous by UK government, there remain acute challenges with limited opportunities.

  1. Guidance on the diagnosis and management of asthma among adults in resource limited settings

    NARCIS (Netherlands)

    Kirenga, Bruce J.; Schwartz, Jeremy I.; de Jong, Corina; van der Molen, Thys; Okot-Nwang, Martin

    2015-01-01

    BACKGROUND: Optimal management of asthma in resource limited settings is hindered by lack of resources, making it difficult for health providers to adhere to international guidelines. The purpose of this review is to identify steps for asthma diagnosis and management in resource limited settings. ME

  2. Venous Ultrasound (Extremities)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Venous (Extremities) Venous ultrasound uses sound waves to ... limitations of Venous Ultrasound Imaging? What is Venous Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  3. Frequency of Painful Shoulder Limitation of Motion after Long Casting of Upper Extremity

    Directory of Open Access Journals (Sweden)

    A.R. Yavarikia

    2004-01-01

    Full Text Available The aim of this study was determination of frequency of painful reduced shoulder motion after long casting of upper extremity and its relation with age , sex and education . The present work was a descriptive analytic prospective study and included 388 patients who referred to Mobasher hospital of Hamadan during 2001. The selected patients in recurrent referring to orthopedic department were classified to 10 age groups and were examined by researcher in 1 , 1.5 and 3 months after treatment and data was collected in check list. The primary data were analyzed with 2 & Anova by employing EPI 6. Out of 388 studied patients 73.5% after 3 months had no mobility limitation and 26.5% had some limitation. There was significant statistical difference in limitation of abduction shoulder joint movement after 1 , 1.5 and 3 months after treatment among 10 different age groups (P<0.05. Mobility limitation of internal rotation after 3 months in 74 cases (19.1%(P=0.0001. Final mobility limitation in 59.5% of female patients and 40.5% of male patients(P=0.001. Mobility limitation in 54.1% of illiterate people , 24.5% under high school diploma and 21.4% high school diploma and higher. Painful limitation of motion in 50-80 year aged is most frequent, then early mobility and physiotherapy in this age range is indicated. There is significant relation between sex and frozen shoulder and it is more common in females also in illiterate people.

  4. Quasinormal modes in the extreme Kerr limit and asymptotic behavior of the Sasaki-Nakamura transformation

    CERN Document Server

    Nakano, Hiroyuki; Tanaka, Takahiro; Nakamura, Takashi

    2016-01-01

    The Sasaki-Nakamura transformation gives a short-ranged potential and a convergent source term for the master equation of perturbations in the Kerr space-time. In this paper, we study the asymptotic behavior of the transformation, and present a new relaxed necessary and sufficient condition of the transformation to obtain the short-ranged potential in the assumption that the transformation converges in the far distance. Also, we discuss quasinormal mode frequencies which are determined by the information around the peak of the potential in the WKB analysis. Finally, in the extreme Kerr limit, $a/M \\to 1$, where $M$ and $a$ denote the mass and spin parameter of a Kerr black hole, respectively, we find the peak location of the potential, $r_p/M \\lesssim 1 + 1.8 \\,(1-a/M)^{1/2}$ by using the new transformation. The uncertainty of the location is as large as that expected from the equivalence principle.

  5. Spatially inhomogeneous electron state deep in the extreme quantum limit of strontium titanate.

    Science.gov (United States)

    Bhattacharya, Anand; Skinner, Brian; Khalsa, Guru; Suslov, Alexey V

    2016-09-29

    When an electronic system is subjected to a sufficiently strong magnetic field that the cyclotron energy is much larger than the Fermi energy, the system enters the extreme quantum limit (EQL) and becomes susceptible to a number of instabilities. Bringing a three-dimensional electronic system deeply into the EQL can be difficult however, since it requires a small Fermi energy, large magnetic field, and low disorder. Here we present an experimental study of the EQL in lightly-doped single crystals of strontium titanate. Our experiments probe deeply into the regime where theory has long predicted an interaction-driven charge density wave or Wigner crystal state. A number of interesting features arise in the transport in this regime, including a striking re-entrant nonlinearity in the current-voltage characteristics. We discuss these features in the context of possible correlated electron states, and present an alternative picture based on magnetic-field induced puddling of electrons.

  6. Limitations and pitfalls of climate change impact analysis on urban rainfall extremes

    DEFF Research Database (Denmark)

    Willems, P.; Olsson, J.; Arnbjerg-Nielsen, Karsten

    to anthropogenic climate change. Current practices have several limitations and pitfalls, which are important to be considered by trend or climate change impact modellers and users of trend/impact results. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified...... and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing with other objectives will become ever more important to keep our cities liveable into the future.......Under the umbrella of the IWA/IAHR Joint Committee on Urban Drainage, the International Working Group on Urban Rainfall (IGUR) has reviewed existing methodologies for the analysis of long-term historical and future trends in urban rainfall extremes and their effects on urban drainage systems, due...

  7. Limitations of web-based rubric resources: Addressing the challenges

    Directory of Open Access Journals (Sweden)

    Michele M. Dornisch

    2006-03-01

    Full Text Available As a wider variety of meaningful assessment strategies come into more prominent classroom use, teachers are called upon to craft scoring rubrics which validly and reliably assess students' knowledge and abilities. The creation of instructionally sound rubrics can be time consuming, and many teachers feeling the pinch of time pressures are turning to rubric resources from the World Wide Web for assistance. The purposes of this paper are to review the issues surrounding the creation of instructionally sound rubrics, to examine how those issues apply to online rubric banks and rubric generators, and to offer guidelines for how educators can use online resources to best support the creation of meaningful and effective rubrics.

  8. Adaptive Resource and Job Management for Limited Power Consumption

    OpenAIRE

    2015-01-01

    International audience; The last decades have been characterized by anever growing requirement in terms of computing and storage resources.This tendency has recently put the pressure on the abilityto efficiently manage the power required to operate the hugeamount of electrical components associated with state-of-the-arthigh performance computing systems. The power consumption ofa supercomputer needs to be adjusted based on varying powerbudget or electricity availabilities. As a consequence, R...

  9. Dependencies of Europe's economy on water resources outside its borders and its vulnerability to weather extremes

    Science.gov (United States)

    Chico Zamanillo, Daniel; Chapagain, Ashok; Ercin, Ertug

    2017-04-01

    Europe's economy is dependent on water resources elsewhere in the world since many of the goods consumed in the EU are not produced domestically, but abroad. Reliance on food, energy and goods produced in regions outside of the EU may impose water related risks on different economic sectors within the EU due to vulnerability of water resources used in their production to hydrological extremes and climate change. IMPREX project addresses this economic dependency and water resources vulnerability to hydrological extremes and climate change under WP12 "Water Economy". This study presents the results of the first task of WP12, mapping current dependencies of European economy on water resources outside its borders and their vulnerability to drought and water scarcity. In our assessment, we have used water footprint, which is a measure of the appropriation of freshwater resources for human activities, and is comprised of three components - green (consumption of rainfall), blue (consumption of surface and groundwater) and grey (refers to water pollution). We first calculated virtual water import, the amount of water consumed in producing products imported to the EU, and we identified key products - those making up the largest virtual water inflows to the EU. After mapping the dependencies, we assessed water scarcity and drought severity in producing locations. Coupling this with the water footprint enabled us to map the EU's external water dependencies and to identify when and where vulnerabilities may lie, in terms of blue water scarcity and drought. Overall, external green water resources account for 41% of the total green water footprint of the EU's economy. Soybean, cocoa, coffee, oil palm, sunflower, maize and olives are identified as key products from the perspective of green virtual water import to the EU. Soybean is the crop with the largest virtual water import volume to the EU with imports coming from Argentina, Brazil and USA. Europe relies on soybean import to

  10. Resources

    Science.gov (United States)

    ... resources Alzheimer's - resources Anorexia nervosa - resources Arthritis - resources Asthma and allergy - resources Autism - resources Blindness - resources BPH - resources Breastfeeding - resources Bulimia - resources Burns - resources Cancer - resources Cerebral ...

  11. 28 CFR 16.92 - Exemption of Environment and Natural Resources Division Systems-limited access.

    Science.gov (United States)

    2010-07-01

    ....92 Exemption of Environment and Natural Resources Division Systems—limited access. (a)(1) The...) Environment and Natural Resources Division Case and Related Files System, JUSTICE/ENRD-003. (ii) (2) These..., the applicable exemption may be waived by the Environment and Natural Resources Division. (b)...

  12. Landau spectrum and twin boundaries of bismuth in the extreme quantum limit.

    Science.gov (United States)

    Zhu, Zengwei; Fauqué, Benoît; Malone, Liam; Antunes, Arlei Borba; Fuseya, Yuki; Behnia, Kamran

    2012-09-11

    The Landau spectrum of bismuth is complex and includes many angle-dependent lines in the extreme quantum limit. The adequacy of single-particle theory to describe this spectrum in detail has been an open issue. Here, we present a study of angle-resolved Nernst effect in bismuth, which maps the angle-resolved Landau spectrum for the entire solid angle up to 28 T. The experimental map is in good agreement with the results of a theoretical model with parabolic dispersion for holes and an extended Dirac Hamiltonian for electrons. The angular dependence of additional lines in the Landau spectrum allows us to uncover the mystery of their origin. They correspond to the lines expected for the hole Landau levels in a secondary crystal tilted by 108°, the angle between twinned crystals in bismuth. According to our results, the electron reservoirs of the two identical tilted crystals have different chemical potentials, and carriers across the twin boundary have different concentrations. An exceptional feature of this junction is that it separates two electron-hole compensated reservoirs. The link between this edge singularity and the states wrapping a three-dimensional electron gas in the quantum limit emerges as an outstanding open question.

  13. Online Nutrition Education: Enhancing Opportunities for Limited-Resource Learners

    Science.gov (United States)

    Case, Patty; Cluskey, Mary; Hino, Jeff

    2011-01-01

    Delivering nutrition education using the Internet could allow educators to reach larger audiences at lower cost. Low-income adults living in a rural community participated in focus groups to examine their interest in, experience with, and motivators to accessing nutrition education online. This audience described limited motivation in seeking…

  14. Online Nutrition Education: Enhancing Opportunities for Limited-Resource Learners

    Science.gov (United States)

    Case, Patty; Cluskey, Mary; Hino, Jeff

    2011-01-01

    Delivering nutrition education using the Internet could allow educators to reach larger audiences at lower cost. Low-income adults living in a rural community participated in focus groups to examine their interest in, experience with, and motivators to accessing nutrition education online. This audience described limited motivation in seeking…

  15. Acute rheumatic fever and rheumatic heart disease in resource-limited settings.

    Science.gov (United States)

    Watson, Gabriella; Jallow, Bintou; Le Doare, Kirsty; Pushparajah, Kuberan; Anderson, Suzanne T

    2015-04-01

    Poststreptococcal complications, such as acute rheumatic fever (ARF) and rheumatic heart disease (RHD), are common in resource-limited settings, with RHD recognised as the most common cause of paediatric heart disease worldwide. Managing these conditions in resource-limited settings can be challenging. We review the investigation and treatment options for ARF and RHD and, most importantly, prevention methods in an African setting.

  16. Combined Approach to the Analysis of Rainfall Super-Extremes in Locations with Limited Observational Records.

    Science.gov (United States)

    Lakshmi, V.; Libertino, A.; Sharma, A.; Claps, P.

    2015-12-01

    The prospect of climatic change and its impacts have brought spatial statistics of extreme events into sharper focus. The so-called "water bombs" are predicted to become more frequent in the extra-tropical regions, and, actually, they raise serious concerns in some regions of the Mediterranean area. However, quantitative statistical methods to properly account for the probability of occurrence of these super-extreme events are still lacking, due to their rare occurrence and to the limited spatial scale at which these events occur. In order to overcome the lack of data, we propose at first to exploit the information derived from remote sensed datasets. Despite the coarser resolution, these databases are able to provide information continuous in space and time, overcoming the problems related to the discontinuous nature of rainfall measurements. We propose to apply such a kind of approach with the adoption of a Bayesian framework, aimed at combining local measurements with climatic regional information, conditioning the exceedance probability on the large and mesoscale characteristics of the system. The case study refers to an area located in the North-West of Italy, historically affected by extraordinary precipitation events. We use a dataset of daily at-gauge rainfall measurements extracted from the NOAA GHCN-Daily dataset, combined with the ones provided by some local Environmental Agencies. Daily estimations from the TRMM are adopted too. First, we identify the most intense events occurred in the area, combining the information from the different datasets. Analysing the related synoptic conditions with the reanalysis of the ECMWF, we then define the conditional variables and the hierarchical relationships between the events and their type. Different climatic configurations that combined with the local morphology and the seasonal condition of the Mediterranean Sea can triggers very intense precipitation events are identified. The results, compared with those

  17. Bush animal attacks: management of complex injuries in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    Mitchell Katrina B

    2011-12-01

    Full Text Available Abstract Introduction Though animal-related injuries and fatalities have been documented throughout the world, the variety of attacks by wild animals native to rural East Africa are less commonly described. Given the proximity of our northwestern Tanzania hospital to Lake Victoria, Lake Tanganyika, and the Serengeti National Park, and presentation of several patients attacked by bush animals and suffering a variety of complex injuries, we sought to report the pattern of attacks and surgical management in a resource-limited setting. Materials and methods Four patients who were admitted to the northwestern Tanzania tertiary referral hospital, Bugando Medical Centre (BMC, in 2010-2011 suffered attacks by different bush animals: hyena, elephant, crocodile, and vervet monkey. These patients were triaged as trauma patients in the Casualty Ward, then admitted for inpatient monitoring and treatment. Their outcomes were followed to discharge. Results The age and gender of the patients attacked was variable, though all but the pediatric patient were participating in food gathering or guarding activities in rural locations at the time of the attacks. All patients required surgical management of their injuries, which included debridement and closure of wounds, chest tube insertion, amputation, and external fixation of an extremity fracture. All patients survived and were discharged home. Discussion Though human injuries secondary to encounters with undomesticated animals such as cows, moose, and camel are reported, they often are indirect traumas resulting from road traffic collisions. Snake attacks are well documented and common. However, this series of unique bush animal attacks describes the initial and surgical management of human injuries in the resource-limited setting of the developing world. Conclusion Animal attacks are common throughout the world, but their pattern may vary in Africa throughout jungle and bush environmental settings. It is

  18. A Semi-Preemptive Computational Service System with Limited Resources and Dynamic Resource Ranking

    Directory of Open Access Journals (Sweden)

    Fang-Yie Leu

    2012-03-01

    Full Text Available In this paper, we integrate a grid system and a wireless network to present a convenient computational service system, called the Semi-Preemptive Computational Service system (SePCS for short, which provides users with a wireless access environment and through which a user can share his/her resources with others. In the SePCS, each node is dynamically given a score based on its CPU level, available memory size, current length of waiting queue, CPU utilization and bandwidth. With the scores, resource nodes are classified into three levels. User requests based on their time constraints are also classified into three types. Resources of higher levels are allocated to more tightly constrained requests so as to increase the total performance of the system. To achieve this, a resource broker with the Semi-Preemptive Algorithm (SPA is also proposed. When the resource broker cannot find suitable resources for the requests of higher type, it preempts the resource that is now executing a lower type request so that the request of higher type can be executed immediately. The SePCS can be applied to a Vehicular Ad Hoc Network (VANET, users of which can then exploit the convenient mobile network services and the wireless distributed computing. As a result, the performance of the system is higher than that of the tested schemes.

  19. High Resolution Modeling in Mountainous Terrain for Water Resource Management: AN Extreme Precipitation Event Case Study

    Science.gov (United States)

    Masarik, M. T.; Watson, K. A.; Flores, A. N.; Anderson, K.; Tangen, S.

    2016-12-01

    The water resources infrastructure of the Western US is designed to deliver reliable water supply to users and provide recreational opportunities for the public, as well as afford flood control for communities by buffering variability in precipitation and snow storage. Thus water resource management is a balancing act of meeting multiple objectives while trying to anticipate and mitigate natural variability of water supply. Currently, the forecast guidance available to personnel managing resources in mountainous terrain is lacking in two ways: the spatial resolution is too coarse, and there is a gap in the intermediate time range (10-30 days). To address this need we examine the effectiveness of using the Weather Research and Forecasting (WRF) model, a state of the art, regional, numerical weather prediction model, as a means to generate high-resolution weather guidance in the intermediate time range. This presentation will focus on a reanalysis and hindcasting case study of the extreme precipitation and flooding event in the Payette River Basin of Idaho during the period of June 2nd-4th, 2010. For the reanalysis exercise we use NCEP's Climate Forecast System Reanalysis (CFSR) and the North American Regional Reanalysis (NARR) data sets as input boundary conditions to WRF. The model configuration includes a horizontal spatial resolution of 3km in the outer nest, and 1 km in the inner nest, with output temporal resolution of 3 hrs and 1 hr, respectively. The hindcast simulations, which are currently underway, will make use of the NCEP Climate Forecast System Reforecast (CFSRR) data. The current state of these runs will be discussed. Preparations for the second of two components in this project, weekly WRF forecasts during the intense portion of the water year, will be briefly described. These forecasts will use the NCEP Climate Forecast System version 2 (CFSv2) operational forecast data as boundary conditions to provide forecast guidance geared towards water resource

  20. Welfare and Economy on a Planet with Limited Resources

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    1997-01-01

    The environmental problems we are facing are only symptoms of a too high throughput of materials and energy. The basic causes of this are 1)population, 2)material affluence, and 3)environmental efficiency of the technology used. The paper deals with the possibilities for adapting these three...... factors in order to reach a sustainable development. Especially discussed are the issues around growth and saturation in the economy. Also the substantial but after all limited option for improving the technology is outlined and discussed. A study of the option for reducing electricity consumption...... in Western Europe is used as a case....

  1. Efficient medical image access in diagnostic environments with limited resources

    Directory of Open Access Journals (Sweden)

    José Eduardo Venson

    Full Text Available Abstract Introduction A medical application running outside the workstation environment has to deal with several constraints, such as reduced available memory and low network bandwidth. The aim of this paper is to present an approach to optimize the data flow for fast image transfer and visualization on mobile devices and remote stationary devices. Methods We use a combination of client- and server-side procedures to reduce the amount of information transferred by the application. Our approach was implemented on top of a commercial PACS and evaluated through user experiments with specialists in typical diagnosis tasks. The quality of the system outcome was measured in relation to the accumulated amount of network data transference and the amount of memory used in the host device. Besides, the system's quality of use (usability was measured through participants’ feedback. Results Contrarily to previous approaches, ours keeps the application within the memory constraints, minimizing data transferring whenever possible, allowing the application to run on a variety of devices. Moreover, it does that without sacrificing the user experience. Experimental data point that over 90% of the users did not notice any delays or degraded image quality, and when they did, they did not impact on the clinical decisions. Conclusion The combined activities and orchestration of our methods allow the image viewer to run on resource-constrained environments, such as those with low network bandwidth or little available memory. These results demonstrate the ability to explore the use of mobile devices as a support tool in the medical workflow.

  2. Are gas exchange responses to resource limitation and defoliation linked to source:sink relationships?

    Science.gov (United States)

    Pinkard, E A; Eyles, A; O'Grady, A P

    2011-10-01

    Productivity of trees can be affected by limitations in resources such as water and nutrients, and herbivory. However, there is little understanding of their interactive effects on carbon uptake and growth. We hypothesized that: (1) in the absence of defoliation, photosynthetic rate and leaf respiration would be governed by limiting resource(s) and their impact on sink limitation; (2) photosynthetic responses to defoliation would be a consequence of changing source:sink relationships and increased availability of limiting resources; and (3) photosynthesis and leaf respiration would be adjusted in response to limiting resources and defoliation so that growth could be maintained. We tested these hypotheses by examining how leaf photosynthetic processes, respiration, carbohydrate concentrations and growth rates of Eucalyptus globulus were influenced by high or low water and nitrogen (N) availability, and/or defoliation. Photosynthesis of saplings grown with low water was primarily sink limited, whereas photosynthetic responses of saplings grown with low N were suggestive of source limitation. Defoliation resulted in source limitation. Net photosynthetic responses to defoliation were linked to the degree of resource availability, with the largest responses measured in treatments where saplings were ultimately source rather than sink limited. There was good evidence of acclimation to stress, enabling higher rates of C uptake than might otherwise have occurred. © 2011 Blackwell Publishing Ltd.

  3. Present limits to heat-adaptability in corals and population-level responses to climate extremes.

    Directory of Open Access Journals (Sweden)

    Bernhard M Riegl

    Full Text Available Climate change scenarios suggest an increase in tropical ocean temperature by 1-3°C by 2099, potentially killing many coral reefs. But Arabian/Persian Gulf corals already exist in this future thermal environment predicted for most tropical reefs and survived severe bleaching in 2010, one of the hottest years on record. Exposure to 33-35°C was on average twice as long as in non-bleaching years. Gulf corals bleached after exposure to temperatures above 34°C for a total of 8 weeks of which 3 weeks were above 35°C. This is more heat than any other corals can survive, providing an insight into the present limits of holobiont adaptation. We show that average temperatures as well as heat-waves in the Gulf have been increasing, that coral population levels will fluctuate strongly, and reef-building capability will be compromised. This, in combination with ocean acidification and significant local threats posed by rampant coastal development puts even these most heat-adapted corals at risk. WWF considers the Gulf ecoregion as "critically endangered". We argue here that Gulf corals should be considered for assisted migration to the tropical Indo-Pacific. This would have the double benefit of avoiding local extinction of the world's most heat-adapted holobionts while at the same time introducing their genetic information to populations naïve to such extremes, potentially assisting their survival. Thus, the heat-adaptation acquired by Gulf corals over 6 k, could benefit tropical Indo-Pacific corals who have <100 y until they will experience a similarly harsh climate. Population models suggest that the heat-adapted corals could become dominant on tropical reefs within ∼20 years.

  4. Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates.

    Science.gov (United States)

    Caldeira, Maria C; Lecomte, Xavier; David, Teresa S; Pinto, Joaquim G; Bugalho, Miguel N; Werner, Christiane

    2015-01-01

    Extreme drought events and plant invasions are major drivers of global change that can critically affect ecosystem functioning and alter ecosystem-atmosphere exchange. Invaders are expanding worldwide and extreme drought events are projected to increase in frequency and intensity. However, very little is known on how these drivers may interact to affect the functioning and resilience of ecosystems to extreme events. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that native shrub invasion and extreme drought synergistically reduced ecosystem transpiration and the resilience of key-stone oak tree species. Ecosystem transpiration was dominated by the water use of the invasive shrub Cistus ladanifer, which further increased after the extreme drought event. Meanwhile, the transpiration of key-stone tree species decreased, indicating a competitive advantage in favour of the invader. Our results suggest that in Mediterranean-type climates the invasion of water spending species and projected recurrent extreme drought events may synergistically cause critical drought tolerance thresholds of key-stone tree species to be surpassed, corroborating observed higher tree mortality in the invaded ecosystems. Ultimately, this may shift seasonally water limited ecosystems into less desirable alternative states dominated by water spending invasive shrubs.

  5. Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates

    Science.gov (United States)

    Caldeira, Maria C.; Lecomte, Xavier; David, Teresa S.; Pinto, Joaquim G.; Bugalho, Miguel N.; Werner, Christiane

    2015-10-01

    Extreme drought events and plant invasions are major drivers of global change that can critically affect ecosystem functioning and alter ecosystem-atmosphere exchange. Invaders are expanding worldwide and extreme drought events are projected to increase in frequency and intensity. However, very little is known on how these drivers may interact to affect the functioning and resilience of ecosystems to extreme events. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that native shrub invasion and extreme drought synergistically reduced ecosystem transpiration and the resilience of key-stone oak tree species. Ecosystem transpiration was dominated by the water use of the invasive shrub Cistus ladanifer, which further increased after the extreme drought event. Meanwhile, the transpiration of key-stone tree species decreased, indicating a competitive advantage in favour of the invader. Our results suggest that in Mediterranean-type climates the invasion of water spending species and projected recurrent extreme drought events may synergistically cause critical drought tolerance thresholds of key-stone tree species to be surpassed, corroborating observed higher tree mortality in the invaded ecosystems. Ultimately, this may shift seasonally water limited ecosystems into less desirable alternative states dominated by water spending invasive shrubs.

  6. Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

    Science.gov (United States)

    Vishniac, H. S.

    1985-01-01

    The high, dry valleys of the Ross Desert of Antarctic, characterized by extremely low temperatures, aridity and a depauperate biota, are used as an analog of the postulated extreme climates of other planetary bodies of the Solar System to test the hypothesis that if life could be supported by Ross, it might be possible where similar conditions prevail. The previously considered sterility of the Ross Desert soil ecosystem has yielded up an indigenous yeast, Cryptoccus vishniacci, which is able to resist the extremes of cold, wet and dry freezing, and long arid periods, while making minimal nutritional demands on the soil.

  7. Analytical models for well-mixed populations of cooperators and defectors under limiting resources

    CERN Document Server

    Requejo, Rubén J; 10.1103/PhysRevE.85.066112

    2012-01-01

    In the study of the evolution of cooperation, resource limitations are usually assumed just to provide a finite population size. Recently, however, agent-based models have pointed out that resource limitation may modify the original structure of the interactions and allow for the survival of unconditional cooperators in well-mixed populations. Here, we present analytical simplified versions of two types of agent-based models recently published: one in which the limiting resource constrains the ability of reproduction of individuals but not their survival, and a second one where the limiting resource is necessary for both reproduction and survival. One finds that the analytical models display, with a few differences, the same qualitative behavior of the more complex agent-based models. In addition, the analytical models allow us to expand the study and identify the dimensionless parameters governing the final fate of the system, such as coexistence of cooperators and defectors, or dominance of defectors or of ...

  8. Justification of Filter Selection for Robot Balancing in Conditions of Limited Computational Resources

    Science.gov (United States)

    Momot, M. V.; Politsinskaia, E. V.; Sushko, A. V.; Semerenko, I. A.

    2016-08-01

    The paper considers the problem of mathematical filter selection, used for balancing of wheeled robot in conditions of limited computational resources. The solution based on complementary filter is proposed.

  9. Influenza transmission during extreme indoor conditions in a low-resource tropical setting

    Science.gov (United States)

    Tamerius, James; Ojeda, Sergio; Uejio, Christopher K.; Shaman, Jeffrey; Lopez, Brenda; Sanchez, Nery; Gordon, Aubree

    2017-04-01

    Influenza transmission occurs throughout the planet across wide-ranging environmental conditions. However, our understanding of the environmental factors mediating transmission is evaluated using outdoor environmental measurements, which may not be representative of the indoor conditions where influenza is transmitted. In this study, we examined the relationship between indoor environment and influenza transmission in a low-resource tropical population. We used a case-based ascertainment design to enroll 34 households with a suspected influenza case and then monitored households for influenza, while recording indoor temperature and humidity data in each household. We show that the indoor environment is not commensurate with outdoor conditions and that the relationship between indoor and outdoor conditions varies significantly across homes. We also show evidence of influenza transmission in extreme indoor environments. Specifically, our data suggests that indoor environments averaged 29 °C, 18 g/kg specific humidity, and 68 % relative humidity across 15 transmission events observed. These indoor settings also exhibited significant temporal variability with temperatures as high as 39 °C and specific and relative humidity increasing to 22 g/kg and 85 %, respectively, during some transmission events. However, we were unable to detect differences in the transmission efficiency by indoor temperature or humidity conditions. Overall, these results indicate that laboratory studies investigating influenza transmission and virus survival should increase the range of environmental conditions that they assess and that observational studies investigating the relationship between environment and influenza activity should use caution using outdoor environmental measurements since they can be imprecise estimates of the conditions that mediate transmission indoors.

  10. Influenza transmission during extreme indoor conditions in a low-resource tropical setting

    Science.gov (United States)

    Tamerius, James; Ojeda, Sergio; Uejio, Christopher K.; Shaman, Jeffrey; Lopez, Brenda; Sanchez, Nery; Gordon, Aubree

    2016-08-01

    Influenza transmission occurs throughout the planet across wide-ranging environmental conditions. However, our understanding of the environmental factors mediating transmission is evaluated using outdoor environmental measurements, which may not be representative of the indoor conditions where influenza is transmitted. In this study, we examined the relationship between indoor environment and influenza transmission in a low-resource tropical population. We used a case-based ascertainment design to enroll 34 households with a suspected influenza case and then monitored households for influenza, while recording indoor temperature and humidity data in each household. We show that the indoor environment is not commensurate with outdoor conditions and that the relationship between indoor and outdoor conditions varies significantly across homes. We also show evidence of influenza transmission in extreme indoor environments. Specifically, our data suggests that indoor environments averaged 29 °C, 18 g/kg specific humidity, and 68 % relative humidity across 15 transmission events observed. These indoor settings also exhibited significant temporal variability with temperatures as high as 39 °C and specific and relative humidity increasing to 22 g/kg and 85 %, respectively, during some transmission events. However, we were unable to detect differences in the transmission efficiency by indoor temperature or humidity conditions. Overall, these results indicate that laboratory studies investigating influenza transmission and virus survival should increase the range of environmental conditions that they assess and that observational studies investigating the relationship between environment and influenza activity should use caution using outdoor environmental measurements since they can be imprecise estimates of the conditions that mediate transmission indoors.

  11. Coexistence and limiting similarity of consumer species competing for a linear array of resources.

    Science.gov (United States)

    Abrams, Peter A; Rueffler, Claus

    2009-03-01

    Consumer-resource systems with linear arrays of substitutable resources form the conceptual basis of much of present-day competition theory. However, most analyses of the limiting similarity of competitors have only employed consumer-resource models as a justification for using the Lotka-Volterra competition equations to represent the interaction. Unfortunately, Lotka-Volterra models cannot reflect resource exclusion via apparent competition and are poor approximations of systems with nonlogistic resource growth. We use consumer-resource models to examine the impact of exclusion of biotic resources or depletion of abiotic resources on the ability of three consumer species to coexist along a one-dimensional resource axis. For a wide range of consumer-resource models, coexistence conditions can become more restrictive with increasing niche separation of the two outer species. This occurs when the outer species are highly efficient; in this case they cause extinction or severe depletion of intermediate resources when their own niches have an intermediate level of separation. In many cases coexistence of an intermediate consumer species is prohibited when niche separation of the two outer species is moderately large, but not when it is small. Coexistence may be most likely when the intermediate species is closer to one of the two outer species, contrary to previous theory. These results suggest that competition may lead to uneven spacing of utilization curves. The implications and range of applicability of the models are discussed.

  12. Estimation of fatigue and extreme load distributions from limited data with application to wind energy systems.

    Energy Technology Data Exchange (ETDEWEB)

    Fitzwater, LeRoy M. (Stanford University, Stanford, CA)

    2004-01-01

    An estimate of the distribution of fatigue ranges or extreme loads for wind turbines may be obtained by separating the problem into two uncoupled parts, (1) a turbine specific portion, independent of the site and (2) a site-specific description of environmental variables. We consider contextually appropriate probability models to describe the turbine specific response for extreme loads or fatigue. The site-specific portion is described by a joint probability distribution of a vector of environmental variables, which characterize the wind process at the hub-height of the wind turbine. Several approaches are considered for combining the two portions to obtain an estimate of the extreme load, e.g., 50-year loads or fatigue damage. We assess the efficacy of these models to obtain accurate estimates, including various levels of epistemic uncertainty, of the turbine response.

  13. Limit theory for the sample autocorrelations and extremes of a GARCH (1,1) process

    NARCIS (Netherlands)

    Mikosch, T; Starica, C

    2000-01-01

    The asymptotic theory for the sample autocorrelations and extremes of a GARCH(I, 1) process is provided. Special attention is given to the case when the sum of the ARCH and GARCH parameters is close to 1, that is, when one is close to an infinite Variance marginal distribution. This situation has be

  14. A neuroscience approach to optimizing brain resources for human performance in extreme environments.

    Science.gov (United States)

    Paulus, Martin P; Potterat, Eric G; Taylor, Marcus K; Van Orden, Karl F; Bauman, James; Momen, Nausheen; Padilla, Genieleah A; Swain, Judith L

    2009-07-01

    Extreme environments requiring optimal cognitive and behavioral performance occur in a wide variety of situations ranging from complex combat operations to elite athletic competitions. Although a large literature characterizes psychological and other aspects of individual differences in performances in extreme environments, virtually nothing is known about the underlying neural basis for these differences. This review summarizes the cognitive, emotional, and behavioral consequences of exposure to extreme environments, discusses predictors of performance, and builds a case for the use of neuroscience approaches to quantify and understand optimal cognitive and behavioral performance. Extreme environments are defined as an external context that exposes individuals to demanding psychological and/or physical conditions, and which may have profound effects on cognitive and behavioral performance. Examples of these types of environments include combat situations, Olympic-level competition, and expeditions in extreme cold, at high altitudes, or in space. Optimal performance is defined as the degree to which individuals achieve a desired outcome when completing goal-oriented tasks. It is hypothesized that individual variability with respect to optimal performance in extreme environments depends on a well "contextualized" internal body state that is associated with an appropriate potential to act. This hypothesis can be translated into an experimental approach that may be useful for quantifying the degree to which individuals are particularly suited to performing optimally in demanding environments.

  15. Extreme drought event and shrub invasion combine to reduce ecosystem functioning and resilience in water-limited climates

    Science.gov (United States)

    Caldeira, Maria; Lecomte, Xavier; David, Teresa; Pinto, Joaquim; Bugalho, Miguel; Werner, Christiane

    2016-04-01

    ). Caldeira M.C., Lecomte X., David T.S., Pinto J.G., Bugalho M.N. & Werner C. (2015). Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates. Scientific Reports, 5, 15110.

  16. The limits of the adaptation of life to extreme conditions (in connection with problems of exobiology)

    Science.gov (United States)

    Aksenov, S. I.

    1973-01-01

    Accommodation is discussed as a universal evolutionary principle which essentially will apply to all life forms, regardless of chemical base (carbon, silicon, etc.). Life forms must either adapt to extreme conditions or perish, and for any life form an extremum factor is any significant deviation in environmental parameters. The possibility of life forms existing in specific extraterrestrial environments is discussed, and a conclusion is drawn which unequivocally states that through many forms of accommodation life is possible in many different environments.

  17. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  18. Near-horizon circular orbits and extremal limit for dirty rotating black holes

    CERN Document Server

    Zaslavskii, O B

    2015-01-01

    We consider generic rotating axially symmetric "dirty" (surrounded by matter) black holes. Near-horizon circular equatorial orbits are examined in two different cases of near-extremal (small surface gravity $\\kappa $) and exactly extremal black holes. This has a number of qualitative distinctions. In the first case, it is shown that such orbits can lie as close to the horizon as one wishes on suitably chosen slices of space-time when $\\kappa \\rightarrow 0$. This generalizes observation of T.\\ Jacobson Class. Quantum Grav. 28 187001 (2011) made for the Kerr metric. If a black hole is extremal ($\\kappa =0$), circular on-horizon orbits are impossible for massive particles but, in general, are possible in its vicinity. The corresponding black hole parameters determine also the rate with which a fine-tuned particle on the noncircular near-horizon orbit asymptotically approaches the horizon. Properties of orbits under discussion are also related to the Ba% \\~{n}ados-Silk-West effect of high energy collisions near b...

  19. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-12-02

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  20. Effects of irrigation water supply variations on limited resource farming in Conejos County, Colorado

    Science.gov (United States)

    Eckert, Jerry B.; Wang, Erda

    1993-02-01

    Farms in NE Conejos County, Colorado, are characterized by limited resources, uncertain surface flow irrigation systems, and mixed crop-livestock enterprise combinations which are dependent on public grazing resources. To model decision making on these farms, a linear program is developed stressing enterprise choices under conditions of multiple resource constraints. Differential access to grazing resources and irrigation water is emphasized in this research. Regarding the water resource, the model reflects farms situated alternatively on high-, medium-, and low-priority irrigation ditches within the Alamosa-La Jara river system, each with and without supplemental pumping. Differences are found in optimum enterprise mixes, net returns, choice of cropping technology, level of marketings, and other characteristics in response to variations in the availability of irrigation water. Implications are presented for alternative improvement strategies.

  1. Establishing a pediatric cardiac intensive care unit - Special considerations in a limited resources environment

    Directory of Open Access Journals (Sweden)

    Nair Suresh

    2010-01-01

    Full Text Available Pediatric cardiac intensive care has evolved as a distinct discipline in well-established pediatric cardiac programs in developed nations. With increasing demand for pediatric heart surgery in emerging economies, a number of new programs are being established. The development of robust pediatric cardiac intensive care units (PCICU is critical to the success of these programs. Because of substantial resource limitations existing models of PCICU care cannot be applied in their existing forms and structure. A number of challenges need to be addressed to deliver pediatric cardiac intensive care in the developing world. Limitations in infrastructure, human, and material resources call for a number of innovations and adaptations. Additionally, a variety of strategies are required to minimize costs of care to the individual patient. This review provides a framework for the establishment of a new PCICU program in face of resource limitations typically encountered in the developing world and emerging economies.

  2. ASSASYING THE NEED OF COMMERCIAL PLASMA VIRAL LOAD TESTING IN RESOURCE LIMITED SETTINGS

    Directory of Open Access Journals (Sweden)

    Arnaw

    2015-09-01

    Full Text Available Around nine million Human Immunodeficiency Virus (HIV infected individuals are on antiretroviral therapy (ART. People living with HIV/AIDS in resource - limited settings where HIV burden is usually high, there is an urgent need of affordable, accessible and inexpensive tests to monitor response to treatment. Quite a few commercially available assay has been introduced to measure Plasma Viral Load (PVL as testing can increase adherence to ART and facilitate timely switching of failing regimens and thus minimizing the development of resistance. We analyzed Nucleic Acid Test (NAT based assay and Non Nucleic Acid Test based assay for PVL testing. Though both the assay has its own advantage and disadvantages, but the use of Non Nucleic Acid Test has an upper hand in resource limited settings. It is the duty of administration, clinicians, microbiologist and health care personnel to introduce appropriate laboratory monitoring assays in resource - limited settings.

  3. The Near-Horizon Limit of the Extreme Rotating d=5 Black Hole as a Homogenous Spacetime

    CERN Document Server

    Alonso-Alberca, N; Ortín, Tomas; Alonso-Alberca, Natxo; Lozano-Tellechea, Ernesto; Ortin, Tomas

    2003-01-01

    We show that the spacetime of the near-horizon limit of the extreme rotating d=5 black hole, which is maximally supersymmetric in N=2,d=5 supergravity for any value of the rotation parameter j\\in [-1,1], is a homogeneous non-symmetric spacetime corresponding to the coset [SO(2,1)xSO(3)]/SO(2) in which the subgroup SO(2) acts both on SO(2,1) and on SO(3).

  4. Maximum Growth Potential and Periods of Resource Limitation in Apple Tree.

    Science.gov (United States)

    Reyes, Francesco; DeJong, Theodore; Franceschi, Pietro; Tagliavini, Massimo; Gianelle, Damiano

    2016-01-01

    Knowledge of seasonal maximum potential growth rates are important for assessing periods of resource limitations in fruit tree species. In this study we assessed the periods of resource limitation for vegetative (current year stems, and woody biomass) and reproductive (fruit) organs of a major agricultural crop: the apple tree. This was done by comparing relative growth rates (RGRs) of individual organs in trees with reduced competition for resources to trees grown under standard field conditions. Special attention was dedicated to disentangling patterns and values of maximum potential growth for each organ type. The period of resource limitation for vegetative growth was much longer than in another fruit tree species (peach): from late May until harvest. Two periods of resource limitation were highlighted for fruit: from the beginning of the season until mid-June, and about 1 month prior to harvest. By investigating the variability in individual organs growth we identified substantial differences in RGRs among different shoot categories (proleptic and epicormic) and within each group of monitored organs. Qualitatively different and more accurate values of growth rates for vegetative organs, compared to the use of the simple compartmental means, were estimated. Detailed, source-sink based tree growth models, commonly in need of fine parameter tuning, are expected to benefit from the results produced by these analyses.

  5. Implementation of large kernel 2-D convolution in limited FPGA resource

    Science.gov (United States)

    Zhong, Sheng; Li, Yang; Yan, Luxin; Zhang, Tianxu; Cao, Zhiguo

    2007-12-01

    2-D Convolution is a simple mathematical operation which is fundamental to many common image processing operators. Using FPGA to implement the convolver can greatly reduce the DSP's heavy burden in signal processing. But with the limit resource the FPGA can implement a convolver with small 2-D kernel. In this paper, An FIFO type line delayer is presented to serve as the data buffer for convolution to reduce the data fetching operation. A finite state machine is applied to control the reuse of multipliers and adders arrays. With these two techniques, a resource limited FPGA can be used to implement a larger kernel convolver which is commonly used in image process systems.

  6. Expected climate change impacts on extreme flows in Vietnam: The limits of bias correction techniques

    Science.gov (United States)

    Laux, Patrick; Dang, Thinh; Kunstmann, Harald

    2016-04-01

    We investigate possible impacts of climate change on future floods in the VuGia-ThuBon river basin, central Vietnam using a multi-model climate ensemble. An ensemble of regional climate projections (SRES) derived from different combinations of global and regional climate models in combination with different emission scenarios are used. In order to correct for the biases between the modelled climate variables and the observations, different bias correction techniques such as linear scaling, local intensity scaling, and quantile mapping are applied to the RCM outputs. Bias-corrected and raw climate data are then used as input for the fully distributed hydrological water balance model WaSIM-ETH to reproduce discharge data at NongSon station. Annual maximum discharges are extracted from the modeled daily series from the control period (1980-1999) and the future periods 2011-2030, 2031-2050, and 2080-2099 for subsequent extreme frequency analyses. To derive flood frequency curves for the four time periods, the generalized extreme value probability distribution is fitted to the data. Our analysis shows that actually none of the bias correction approaches applied to the control runs of simulated precipitation data can satisfactorily correct their distributions towards those of the observations. Therefore, this study builds further on the delta change approach, which adjusts the observed extreme values by the derived signals from the hydrological simulations fed by raw future climate projections. Adjusted return periods of e.g. HQ100 values are calculated based on the delta change method. The results inhibit a remarkable variation among the different climate scenarios in representing extreme values. Results show that MRI-MRI, ECHAM3-REMO, HadCMQ10-HadRM3P and HadCMQ13-HadRM3P models always exhibit a positive signal for all considered time slices and climate change scenarios. On the other hand, CCSM-MM5 frequently shows a negative signal for all time slices. On average, an

  7. Extremal rotating black holes in the near-horizon limit: Phase space and symmetry algebra

    Directory of Open Access Journals (Sweden)

    G. Compère

    2015-10-01

    Full Text Available We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to d dimensional Einstein gravity. Each element in the phase space is a geometry with SL(2,R×U(1d−3 isometries which has vanishing SL(2,R and constant U(1 charges. We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries. In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in d>4 dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. The conserved charges are given by the Fourier decomposition of a Liouville-type stress-tensor which depends upon a single periodic function of d−3 angular variables associated with the U(1 isometries. This phase space and in particular its symmetries can serve as a basis for a semiclassical description of extremal rotating black hole microstates.

  8. Patient needs and point-of-care requirements for HIV load testing in resource-limited settings.

    Science.gov (United States)

    Usdin, Martine; Guillerm, Martine; Calmy, Alexandra

    2010-04-15

    Medecins Sans Frontieres (MSF) is an international, independent medical nongovernmental organization. One way in which MSF acts to improve patient care is to assist in the identification and development of adapted and appropriate tools for use in resource-limited settings. One strategy to achieve this goal is through active collaborations with scientists and developers, to make some of the field needs known and to help define the medical strategy behind the implementation of new diagnostic tests. Tests used in the field need to be effective in often extreme conditions and must also deliver high-quality, reliable results that can be used in the local context. In this article, we discuss some patient and health care provider needs for human immunodeficiency virus (HIV) load measurement in resource-limited settings. This is just one of the areas in which effective, quality tools are desperately needed, not only by MSF and other international nongovernmental organizations, but also by many other health service providers. We hope that, by clearly defining the needs of patients in MSF clinics-as well as we can assess this-and by explaining why these tools are needed, how they should perform, and how their results can be integrated into a program, we will encourage the development of such tools and hasten their implementation in areas where they are so urgently needed.

  9. Consequences of resource limitation for recovery from repeated defoliation in Eucalyptus globulus Labilladière.

    Science.gov (United States)

    Barry, Karen M; Quentin, Audrey; Eyles, Alieta; Pinkard, Elizabeth A

    2012-01-01

    Recovery following defoliation can be modified by co-occurring site resource limitations. The growth response of young Eucalyptus globulus saplings to two defoliation events was examined in an experimental plantation with combinations of low (-) or high (+) water (W) and nitrogen (N) resources. Artificial defoliation was applied at 3 and 9 months of age to remove ~40 and 55% of leaf area in the upper crown, respectively. At 18 months of age, height, stem diameter and leaf area were not significantly different between control and defoliated saplings, across all resource treatments. However, stem volume, bark volume and branch number were significantly increased in defoliated saplings, including a significant interaction with resource treatment. Total above-ground biomass of saplings in response to defoliation was significantly higher (almost double) than controls for the low water (N + W-) treatment only. Significantly increased foliar starch content (and a trend for increased soluble sugars) in the upper crown zone was found in the defoliated saplings of the N + W- treatment compared with the upper zone of control saplings. Foliar total non-structural carbohydrates were significantly correlated to stem biomass regardless of resource treatment or defoliation, and we suggest that foliar resources are most important for stem growth in E. globulus rather than stored carbon (C) from other tissues. After repeated defoliation and several months recovery, E. globulus saplings were generally not C limited in this study.

  10. GMLC Extreme Event Modeling -- Slow-Dynamics Models for Renewable Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Korkali, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Min, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-30

    The need for slow dynamics models of renewable resources in cascade modeling essentially arises from the challenges associated with the increased use of solar and wind electric power. Indeed, the main challenge is that the power produced by wind and sunlight is not consistent; thus, renewable energy resources tend to have variable output power on many different timescales, including the timescales that a cascade unfolds.

  11. Policy Recommendations for the Argentinean Water Resources National Plan Related to Extreme Events in Forested Mountain Basins.

    Science.gov (United States)

    Urciuolo, A. B.; Iturraspe, R. J.; Lofiego, R.

    2007-05-01

    In the framework of activities developed by COHIFE (Federal Water Resource Council), Argentina is preparing the Water Resources National Plan. To achieve an integrating project and considering that Argentina is a federal country, each province is working on the basis of its own Water Resources Provincial Plan. The first step of the plan consists in the identification of problems, with the purpose of further defining solutions based on structural and non structural actions. The general perception of the stakeholders involved in the plan development is the necessity of the analysis of strategies for the integrated water resource management Although a first document for water policy, named "Principios Rectores de Política Hídrica" is available, there are not specific strategies for integrated management of water and land use oriented to extreme events. In other way, there are a lack of policies oriented to Mountain basin with forest coverage, may be because of most of the population and the economical structure of the country is located on plain regions. This article proposes recommendations for policy to be integrated to the Water Resources National Plan, based on studies developed in a pilot basin representative of the Andean-Patagonia eco-region, in the framework of the EPIC FORCE proyect, financed by the European Union. Project methodology includes basin instrumentation, reconstruction and analysis of extreme events and land-water management practices revision. Climate, flow and sediment Data are available for simulation using the Shetran model on different land use scenarios, including changes in the basin forest coverage. On the basis of the first results of the project, policy guides oriented to fill mentioned policy lacks were defined.

  12. Revising an Extension Education Website for Limited Resource Audiences Using Social Marketing Theory

    Science.gov (United States)

    Francis, Sarah L.; Martin, Peggy; Taylor, Kristin

    2011-01-01

    Spend Smart Eat Smart (SSES), a unique website combining nutrition and food buying education for limited resource audiences (LRAs), was revised using social marketing theory to make it more appealing and relevant to LRAs (25-40 years). Focus groups and surveys identified the needs and preferences of LRAs. Needs were cooking, basic health, and…

  13. Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings

    DEFF Research Database (Denmark)

    Abdissa, Alemseged; Wiesner, Lubbe; McIlleron, Helen

    2014-01-01

    to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods: The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations...

  14. Revising an Extension Education Website for Limited Resource Audiences Using Social Marketing Theory

    Science.gov (United States)

    Francis, Sarah L.; Martin, Peggy; Taylor, Kristin

    2011-01-01

    Spend Smart Eat Smart (SSES), a unique website combining nutrition and food buying education for limited resource audiences (LRAs), was revised using social marketing theory to make it more appealing and relevant to LRAs (25-40 years). Focus groups and surveys identified the needs and preferences of LRAs. Needs were cooking, basic health, and…

  15. Analytical models for well-mixed populations of cooperators and defectors under limiting resources

    Science.gov (United States)

    Requejo, R. J.; Camacho, J.

    2012-06-01

    In the study of the evolution of cooperation, resource limitations are usually assumed just to provide a finite population size. Recently, however, agent-based models have pointed out that resource limitation may modify the original structure of the interactions and allow for the survival of unconditional cooperators in well-mixed populations. Here, we present analytical simplified versions of two types of agent-based models recently published: one in which the limiting resource constrains the ability of reproduction of individuals but not their survival, and a second one where the limiting resource is necessary for both reproduction and survival. One finds that the analytical models display, with a few differences, the same qualitative behavior of the more complex agent-based models. In addition, the analytical models allow us to expand the study and identify the dimensionless parameters governing the final fate of the system, such as coexistence of cooperators and defectors, or dominance of defectors or of cooperators. We provide a detailed analysis of the occurring phase transitions as these parameters are varied.

  16. Diagnostic point-of-care tests in resource-limited settings.

    Science.gov (United States)

    Drain, Paul K; Hyle, Emily P; Noubary, Farzad; Freedberg, Kenneth A; Wilson, Douglas; Bishai, William R; Rodriguez, William; Bassett, Ingrid V

    2014-03-01

    The aim of diagnostic point-of-care testing is to minimise the time to obtain a test result, thereby allowing clinicians and patients to make a quick clinical decision. Because point-of-care tests are used in resource-limited settings, the benefits need to outweigh the costs. To optimise point-of-care testing in resource-limited settings, diagnostic tests need rigorous assessments focused on relevant clinical outcomes and operational costs, which differ from assessments of conventional diagnostic tests. We reviewed published studies on point-of-care testing in resource-limited settings, and found no clearly defined metric for the clinical usefulness of point-of-care testing. Therefore, we propose a framework for the assessment of point-of-care tests, and suggest and define the term test efficacy to describe the ability of a diagnostic test to support a clinical decision within its operational context. We also propose revised criteria for an ideal diagnostic point-of-care test in resource-limited settings. Through systematic assessments, comparisons between centralised testing and novel point-of-care technologies can be more formalised, and health officials can better establish which point-of-care technologies represent valuable additions to their clinical programmes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The small and rural academic library leveraging resources and overcoming limitations

    CERN Document Server

    Davis Kendrick, Kaetrena

    2016-01-01

    Through the use of case studies, research, and practical interviews, The Small or Rural Academic Library: Leveraging Resources and Overcoming Limitations explores how academic librarians in such environments can keep pace with, create, and improve modern library practices and services, network with colleagues, and access continuing education and professional development opportunities.

  18. Nutrition Education Brings Behavior and Knowledge Change in Limited-Resource Older Adults

    Science.gov (United States)

    McClelland, Jacquelyn W.; Jayaratne, K.S.U.; Bird, Carolyn L.

    2013-01-01

    A prospective, controlled, randomized, crossover design was used to examine a nutrition education curriculum's effects on knowledge and behavior of 463 limited-resource older adults in 13 counties. Counties were randomized to begin with the treatment or control curriculum and then the remaining curriculum. Participants completed a pre-test…

  19. Control of molecular rotation in the limit of extreme rotational excitation

    CERN Document Server

    Milner, V

    2015-01-01

    Laser control of molecular rotation is an area of active research. A number of recent studies has aimed at expanding the reach of rotational control to extreme, previously inaccessible rotational states, as well as controlling the directionality of molecular rotation. Dense ensembles of molecules undergoing ultrafast uni-directional rotation, known as molecular superrotors, are anticipated to exhibit unique properties, from spatially anisotropic diffusion and vortex formation to the creation of powerful acoustic waves and tuneable THz radiation. Here we describe our recent progress in controlling molecular rotation in the regime of high rotational excitation. We review two experimental techniques of producing uni-directional rotational wave packets with a "chiral train" of femtosecond pulses and an "optical centrifuge". Three complementary detection methods, enabling the direct observation, characterization and control of the superrotor states, are outlined: the one based on coherent Raman scattering, and two...

  20. Antenatal management of the expectant mother and extreme preterm infant at the limits of viability.

    LENUS (Irish Health Repository)

    Khan, R

    2012-01-31

    We explored the opinions of healthcare providers on the antenatal management and outcome of preterm delivery at less than 28 weeks gestation. An anonymous postal questionnaire was sent to health care providers. The response rate was 55% (74% Obstetrician, 70% neonatologist). Twenty four weeks is the limit at which most would advocate intervention. At 23 weeks 67% of neonatologists advocate antenatal steroids. 50% of all health care providers advocate cardiotocographic monitoring at 24 weeks gestation. Written information on survival and long-term outcome is provided by 8% of the respondents. Neonatologists (50%) were more likely than obstetrician (40%) to advocate caesarean section at 25 weeks. We conclude that 24 weeks is the limit at which most would advocate intervention. Significant variation exists both between and within each health care group at less than 25 weeks. Establishment and provision of national outcome data may aid decision making at the limits of viability.

  1. Microbial ecology of extreme environments: Antarctic dry valley yeasts and growth in substrate-limited habitats

    Science.gov (United States)

    Vishniac, H. S.

    1982-01-01

    The success of the Antarctic Dry Valley yeasts presumeably results from adaptations to multiple stresses, to low temperatures and substrate-limitation as well as prolonged resting periods enforced by low water availability. Previous investigations have suggested that the crucial stress is substrate limitation. Specific adaptations may be pinpointed by comparing the physiology of the Cryptococcus vishniacii complex, the yeasts of the Tyrol Valley, with their congeners from other habitats. Progress was made in methods of isolation and definition of ecological niches, in the design of experiments in competition for limited substrate, and in establishing the relationships of the Cryptococcus vishniacii complex with other yeasts. In the course of investigating relationships, a new method for 25SrRNA homology was developed. For the first time it appears that 25SrRNA homology may reflect parallel or convergent evolution.

  2. Anaerobic metabolism at thermal extremes: a metabolomic test of the oxygen limitation hypothesis in an aquatic insect.

    Science.gov (United States)

    Verberk, W C E P; Sommer, U; Davidson, R L; Viant, M R

    2013-10-01

    Thermal limits in ectotherms may arise through a mismatch between supply and demand of oxygen. At higher temperatures, the ability of their cardiac and ventilatory activities to supply oxygen becomes insufficient to meet their elevated oxygen demand. Consequently, higher levels of oxygen in the environment are predicted to enhance tolerance of heat, whereas reductions in oxygen are expected to reduce thermal limits. Here, we extend previous research on thermal limits and oxygen limitation in aquatic insect larvae and directly test the hypothesis of increased anaerobic metabolism and lower energy status at thermal extremes. We quantified metabolite profiles in stonefly nymphs under varying temperatures and oxygen levels. Under normoxia, the concept of oxygen limitation applies to the insects studied. Shifts in the metabolome of heat-stressed stonefly nymphs clearly indicate the onset of anaerobic metabolism (e.g., accumulation of lactate, acetate, and alanine), a perturbation of the tricarboxylic acid cycle (e.g., accumulation of succinate and malate), and a decrease in energy status (e.g., ATP), with corresponding decreases in their ability to survive heat stress. These shifts were more pronounced under hypoxic conditions, and negated by hyperoxia, which also improved heat tolerance. Perturbations of metabolic pathways in response to either heat stress or hypoxia were found to be somewhat similar but not identical. Under hypoxia, energy status was greatly compromised at thermal extremes, but energy shortage and anaerobic metabolism could not be conclusively identified as the sole cause underlying thermal limits under hyperoxia. Metabolomics proved useful for suggesting a range of possible mechanisms to explore in future investigations, such as the involvement of leaking membranes or free radicals. In doing so, metabolomics provided a more complete picture of changes in metabolism under hypoxia and heat stress.

  3. National Laboratory Planning: Developing Sustainable Biocontainment Laboratories in Limited Resource Areas.

    Science.gov (United States)

    Yeh, Kenneth B; Adams, Martin; Stamper, Paul D; Dasgupta, Debanjana; Hewson, Roger; Buck, Charles D; Richards, Allen L; Hay, John

    2016-01-01

    Strategic laboratory planning in limited resource areas is essential for addressing global health security issues. Establishing a national reference laboratory, especially one with BSL-3 or -4 biocontainment facilities, requires a heavy investment of resources, a multisectoral approach, and commitments from multiple stakeholders. We make the case for donor organizations and recipient partners to develop a comprehensive laboratory operations roadmap that addresses factors such as mission and roles, engaging national and political support, securing financial support, defining stakeholder involvement, fostering partnerships, and building trust. Successful development occurred with projects in African countries and in Azerbaijan, where strong leadership and a clear management framework have been key to success. A clearly identified and agreed management framework facilitate identifying the responsibility for developing laboratory capabilities and support services, including biosafety and biosecurity, quality assurance, equipment maintenance, supply chain establishment, staff certification and training, retention of human resources, and sustainable operating revenue. These capabilities and support services pose rate-limiting yet necessary challenges. Laboratory capabilities depend on mission and role, as determined by all stakeholders, and demonstrate the need for relevant metrics to monitor the success of the laboratory, including support for internal and external audits. Our analysis concludes that alternative frameworks for success exist for developing and implementing capabilities at regional and national levels in limited resource areas. Thus, achieving a balance for standardizing practices between local procedures and accepted international standards is a prerequisite for integrating new facilities into a country's existing public health infrastructure and into the overall international scientific community.

  4. Setting the research agenda in a resource-limited setting--viewpoint.

    Science.gov (United States)

    Borok, Margaret Z; Busakhala, Naftali; Makadzange, Tariro; Hakim, James

    2014-01-01

    The phenomenon of disproportionately large allocations of global health research resources to relatively limited components of the global health burden is widely acknowledged. Factors contributing to this are explored. The development of a national or regional research agenda is a critical step toward attempting to redress this imbalance. Key areas to be considered are a broad vision, dialogue, and commitment from those stakeholders comprising the "health research triangle": national policy makers and decision makers, key personnel in both health research and health care, and community representatives. The interdependent roles of human, material, and community resources are further examined.

  5. Control limitations from distributed sensing: theory and Extremely Large Telescope application

    OpenAIRE

    Sarlette, Alain; Sepulchre, Rodolphe

    2013-01-01

    We investigate performance bounds for feedback control of distributed plants where the controller can be centralized (i.e. it has access to measurements from the whole plant), but sensors only measure differences between neighboring subsystem outputs. Such "distributed sensing" can be a technological necessity in applications where system size exceeds accuracy requirements by many orders of magnitude. We formulate how distributed sensing generally limits feedback performance robust to measure...

  6. Limitations and pitfalls of climate change impact analysis on urban rainfall extremes

    DEFF Research Database (Denmark)

    Willems, P.; Olsson, J.; Arnbjerg-Nielsen, Karsten;

    to anthropogenic climate change. Current practices have several limitations and pitfalls, which are important to be considered by trend or climate change impact modellers and users of trend/impact results. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified...... and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing with other objectives will become ever more important to keep our cities liveable into the future....

  7. Accuracy of the Tracy--Widom limits for the extreme eigenvalues in white Wishart matrices

    CERN Document Server

    Ma, Zongming

    2012-01-01

    The distributions of the largest and the smallest eigenvalues of a $p$-variate sample covariance matrix $S$ are of great importance in statistics. Focusing on the null case where $nS$ follows the standard Wishart distribution $W_p(I,n)$, we study the accuracy of their scaling limits under the setting: $n/p\\rightarrow \\gamma\\in(0,\\infty)$ as $n\\rightarrow \\infty$. The limits here are the orthogonal Tracy--Widom law and its reflection about the origin. With carefully chosen rescaling constants, the approximation to the rescaled largest eigenvalue distribution by the limit attains accuracy of order ${\\mathrm {O}({\\min(n,p)^{-2/3}})}$. If $\\gamma>1$, the same order of accuracy is obtained for the smallest eigenvalue after incorporating an additional log transform. Numerical results show that the relative error of approximation at conventional significance levels is reduced by over 50% in rectangular and over 75% in `thin' data matrix settings, even with $\\min(n,p)$ as small as 2.

  8. Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

    Science.gov (United States)

    Robertson, J. Gordon; Bland-Hawthorn, Joss

    2012-09-01

    As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably faster than for most spectrograph collimators, while maintaining diffraction-limited imaging quality. It is possible to obtain excellent performance despite these challenges. We also briefly consider the number of such spectrographs required, which can be reduced by full or partial adaptive optics correction, and/or moving towards longer wavelengths.

  9. Pollen and Resource Limitation in Veratrum nigrum L. (Liliaceae), an Andromonoecious Herb

    Institute of Scientific and Technical Information of China (English)

    Wan-Jin Liao; Qing-Fa Song; Da-Yong Zhang

    2006-01-01

    Pollen limitation and resource limitation were invoked to account for the pattern that flowering plants produce more flowers and ovules than fruits and seeds. This study aimed to determine their relative importance in Veratrum nigrum, a self-compatible, perennial, andromonoecious herb. In order to determine whether female production was limited by pollen grains on stigmas or by available resources, we performed supplemental hand pollination in three populations, male-flower-bud removal in three other populations, and emasculation of hermaphroditic flowers in still another population, resulting in a total of seven populations experimentally manipulated. Across the three populations, supplemental hand pollination did not significantly increase fruit set, seed number per fruit, and total seed production per individual,nor did emasculation of hermaphroditic flowers. Taken together, our results suggest that pollen grains deposited on stigmas were abundant enough to fertilize all the ovules. Male-flower-bud removal significantly increased the mean size of hermaphroditic flowers in all three populations. Female reproductive success was increased in one population, but not in the other two populations possibly due to heavy flower/seed predation. We concluded that the female reproductive success of V. nigrum was not limited by pollen grains but by available resources, which is consistent with Bateman's principle. Furthermore, the female reproduction increase of male-flower-bud removal individuals might suggest a trade-off between male and female sexual functions.

  10. Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

    CERN Document Server

    Robertson, J Gordon

    2012-01-01

    As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably ...

  11. Lung cancer management in limited resource settings: guidelines for appropriate good care.

    Science.gov (United States)

    Macbeth, Fergus R; Abratt, Raymond P; Cho, Kwan H; Stephens, Richard J; Jeremic, Branislav

    2007-02-01

    Lung cancer is a major cause of cancer death worldwide and is becoming an increasing problem in developing countries. It is important that, in countries where health care resources are limited, these resources are used most effectively and cost-effectively. The authors, with the support of the International Atomic Energy Agency, drew on existing evidence-based clinical guidelines, published systematic reviews and meta-analyses, as well as recent research publications, to summarise the current evidence and to make broad recommendations on the non-surgical treatment of patients with lung cancer. Tables were constructed which summarise the different treatment options for specific groups of patients, the increase in resource use for and the likely additional clinical benefit from each option. These tables can be used to assess the cost-effectiveness and appropriateness of different interventions in a particular health care system and to develop local clinical guidelines.

  12. Sub-diffraction-limited multilayer coatings for the 0.3-NA Micro-Exposure Tool for extreme ultraviolet lithography

    Energy Technology Data Exchange (ETDEWEB)

    Soufli, R; Hudyma, R M; Spiller, E; Gullikson, E M; Schmidt, M A; Robinson, J C; Baker, S L; Walton, C C; Taylor, J S

    2007-01-03

    This manuscript discusses the multilayer coating results for the primary and secondary mirrors of the Micro Exposure Tool (MET): a 0.30-numerical aperture (NA) lithographic imaging system with 200 x 600 {micro}m{sup 2} field of view at the wafer plane, operating in the extreme ultraviolet (EUV) wavelength region. Mo/Si multilayers were deposited by DC-magnetron sputtering on large-area, curved MET camera substrates, and a velocity modulation technique was implemented to consistently achieve multilayer thickness profiles with added figure errors below 0.1 nm rms to achieve sub-diffraction-limited performance. This work represents the first experimental demonstration of sub-diffraction-limited multilayer coatings for high-NA EUV imaging systems.

  13. Microbial ecology of extreme environments: Antarctic dry valley yeasts and growth in substrate limited habitats

    Science.gov (United States)

    Vishniac, H. S.

    1981-01-01

    The multiple stresses temperature, moisture, and for chemoheterotrophs, sources of carbon and energy of the Dry Valley Antarctica soils allow at best depauperate communities, low in species diversity and population density. The nature of community structure, the operation of biogeochemical cycles, the evolution and mechanisms of adaptation to this habitat are of interest in informing speculations upon life on other planets as well as in modeling the limits of gene life. Yeasts of the Cryptococcus vishniacil complex (Basidiobiastomycetes) are investigated, as the only known indigenes of the most hostile, lichen free, parts of the Dry Valleys. Methods were developed for isolating these yeasts (methods which do not exclude the recovery of other microbiota). The definition of the complex was refined and the importance of nitrogen sources was established as well as substrate competition in fitness to the Dry Valley habitats.

  14. Developments in CD4 and viral load monitoring in resource-limited settings.

    Science.gov (United States)

    Rowley, Christopher F

    2014-02-01

    CD4 counts and human immunodeficiency virus (HIV) load testing are essential components of HIV care, and making these tests available in resource-limited settings is critical to the roll-out of HIV treatment globally. Until recently, the evidence supporting the importance of laboratory monitoring in resource-limited settings was lacking, but there is now a consensus emerging that testing should become routine to ensure the longevity of treatment programs. Low-cost, point-of-care testing offers the potential to fill this role as it potentially improves all aspects of HIV care, ranging from the diagnosis and staging of HIV infection in both infants and adults to monitoring for treatment failure once antiretroviral therapy has been initiated. It is imperative for low-cost solutions to become a reality, but it is equally imperative that close scrutiny be given to each new device that hits the market to ensure they perform optimally in all settings.

  15. A Fuzzy-Oriented Solution for Automatic Distribution of Limited Resources According to Priority Lists

    CERN Document Server

    Pezzetti, M; Tovar-Gonzalez, A; Coppier, H; Almeida, M

    2014-01-01

    This project provides a solution for problems in which there is a limited cryogen resource that supplies several clients in parallel, which can cause the resource’s depletion. This study emerged from the need to solve a specific problem of the Cryogenics Group of the European Organization for Nuclear Research (CERN). A generic solution is proposed for the application in a larger number of situations. The solution is based on the Fuzzy algorithm model, which bases itself on the human reasoning as a problem-solving technique. The Fuzzy approach is presented as well as the limited resource distribution problem, via a cryogenic simulation tools. The paper describes also the comparison of the fuzzy solutions with a former one that has been previously adopted by CERN’s Cryogenic Group.

  16. Novel techniques and future directions in molecular diagnosis of malaria in resource-limited settings.

    Science.gov (United States)

    Oriero, Eniyou Cheryll; Van Geertruyden, Jean-Pierre; Nwakanma, Davis C; D'Alessandro, Umberto; Jacobs, Jan

    2015-01-01

    Despite being preventable and treatable, malaria remains a global health concern with approximately 1.2 billion people at high risk of being infected, 90% of whom are in the resource-limited settings of sub-Saharan Africa. The continued decline in malaria cases globally has rekindled the possibility of elimination in certain regions. As humans constitute the main reservoir of malaria, prompt and accurate diagnosis by microscopy or rapid diagnostic tests is part not only of effective disease management but also of control measures. However, for malaria elimination, more sensitive diagnostic tools are needed to detect asymptomatic and sub-microscopic infections that contribute to transmission. Molecular techniques, which involve amplification of nucleic acids, are being developed and modified to suit this purpose. This report provides a summary of the nucleic acid amplification tests that are currently available for diagnosis of malaria, with current improvements and adaptations for use in resource-limited settings.

  17. Modelling inter-supply chain competition with resource limitation and demand disruption

    Science.gov (United States)

    Chen, Zhaobo; Teng, Chunxian; Zhang, Ding; Sun, Jiayi

    2016-05-01

    This paper proposes a comprehensive model for studying supply chain versus supply chain competition with resource limitation and demand disruption. We assume that there are supply chains with heterogeneous supply network structures that compete at multiple demand markets. Each supply chain is comprised of internal and external firms. The internal firms are coordinated in production and distribution and share some common but limited resources within the supply chain, whereas the external firms are independent and do not share the internal resources. The supply chain managers strive to develop optimal strategies in terms of production level and resource allocation in maximising their profit while facing competition at the end market. The Cournot-Nash equilibrium of this inter-supply chain competition is formulated as a variational inequality problem. We further study the case when there is demand disruption in the plan-execution phase. In such a case, the managers need to revise their planned strategy in order to maximise their profit with the new demand under disruption and minimise the cost of change. We present a bi-criteria decision-making model for supply chain managers and develop the optimal conditions in equilibrium, which again can be formulated by another variational inequality problem. Numerical examples are presented for illustrative purpose.

  18. Management of a posterior mediastinal Gardner fibroma causing critical airway stenosis in a resource limited setting

    Directory of Open Access Journals (Sweden)

    Katie Clouthier, DO

    2017-05-01

    Full Text Available In developed countries, surgeons and anesthesiologists approach the mediastinal mass causing airway compression with prudence and trepidation. Resource-limited settings provide unique challenges in the diagnosis and management of patients with critical airway compression. We report the successful treatment of a patient in Port-au-Prince, Haiti with a posterior mediastinal mass that filled the left chest cavity and caused critical airway stenosis. The pathology revealed a Gardner Fibroma, which is rarely associated with mediastinal airway obstruction.

  19. Disclosure of HIV status to children in resource-limited settings: a systematic review

    Directory of Open Access Journals (Sweden)

    Rachel C Vreeman

    2013-05-01

    Full Text Available Introduction: Informing children of their own HIV status is an important aspect of long-term disease management, yet there is little evidence of how and when this type of disclosure takes place in resource-limited settings and its impact. Methods: MEDLINE, EMBASE and Cochrane Databases were searched for the terms hiv AND disclos* AND (child* OR adolesc*. We reviewed 934 article citations and the references of relevant articles to find articles describing disclosure to children and adolescents in resource-limited settings. Data were extracted regarding prevalence of disclosure, factors influencing disclosure, process of disclosure and impact of disclosure on children and caregivers. Results: Thirty-two articles met the inclusion criteria, with 16 reporting prevalence of disclosure. Of these 16 studies, proportions of disclosed children ranged from 0 to 69.2%. Important factors influencing disclosure included the child's age and perceived ability to understand the meaning of HIV infection and factors related to caregivers, such as education level, openness about their own HIV status and beliefs about children's capacities. Common barriers to disclosure were fear that the child would disclose HIV status to others, fear of stigma and concerns for children's emotional or physical health. Disclosure was mostly led by caregivers and conceptualized as a one-time event, while others described it as a gradual process. Few studies measured the impact of disclosure on children. Findings suggested adherence to antiretroviral therapy (ART improved post-disclosure but the emotional and psychological effects of disclosure were variable. Conclusions: Most studies show that a minority of HIV-infected children in resource-limited settings know his/her HIV status. While caregivers identify many factors that influence disclosure, studies suggest both positive and negative effects for children. More research is needed to implement age- and culture

  20. On state-dependant sampling for nonlinear controlled systems sharing limited computational resources

    OpenAIRE

    Alamir, Mazen

    2007-01-01

    21 pages. soumis à la revue "IEEE Transactions on Automatic Control"; International audience; In this paper, a framework for dynamic monitoring of sampling periods for nonlinear controlled systems is proposed. This framework is particularly adapted to the context of controlled systems sharing limited computational resources. The proposed scheme can be used in a cascaded structure with any feedback scheduling design. Illustrative examples are given to assess the efficiency of the proposed fram...

  1. Revegetation in China’s Loess Plateau is approaching sustainable water resource limits

    Science.gov (United States)

    Feng, Xiaoming; Fu, Bojie; Piao, Shilong; Wang, Shuai; Ciais, Philippe; Zeng, Zhenzhong; Lü, Yihe; Zeng, Yuan; Li, Yue; Jiang, Xiaohui; Wu, Bingfang

    2016-11-01

    Revegetation of degraded ecosystems provides opportunities for carbon sequestration and bioenergy production. However, vegetation expansion in water-limited areas creates potentially conflicting demands for water between the ecosystem and humans. Current understanding of these competing demands is still limited. Here, we study the semi-arid Loess Plateau in China, where the `Grain to Green’ large-scale revegetation programme has been in operation since 1999. As expected, we found that the new planting has caused both net primary productivity (NPP) and evapotranspiration (ET) to increase. Also the increase of ET has induced a significant (p ecological and socio-economic resource demands in a coupled anthropogenic-biological system.

  2. Cultural Health Capital on the margins: Cultural resources for navigating healthcare in communities with limited access.

    Science.gov (United States)

    Madden, Erin Fanning

    2015-05-01

    Communities struggling with access to healthcare in the U.S. are often considered to be disadvantaged and lacking in resources. Yet, these communities develop and nurture valuable strategies for healthcare access that are underrecognized by health scholars. Combining medical sociology and critical race theory perspectives on cultural capital, this paper examines the health-relevant cultural resources, or Cultural Health Capital, in South Texas Mexican American border communities. Ethnographic data collected during 2011-2013 in Cameron and Hidalgo counties on the U.S.-Mexico border provide empirical evidence for expanding existing notions of health-relevant cultural capital. These Mexican American communities use a range of cultural resources to manage healthcare exclusion and negotiate care in alternative healthcare spaces like community clinics, flea markets and Mexican pharmacies. Navigational, social, familial, and linguistic skills and knowledge are used to access doctors and prescription drugs in these spaces despite social barriers to mainstream healthcare (e.g. cost, English language skills, etc.). Cultural capital used in marginalized communities to navigate limited healthcare options may not always fully counteract healthcare exclusion. Nevertheless, recognizing the cultural resources used in Mexican American communities to facilitate healthcare challenges deficit views and yields important findings for policymakers, healthcare providers, and advocates seeking to capitalize on community resources to improve healthcare access. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Withered on the stem: is bamboo a seasonally limiting resource for giant pandas?

    Science.gov (United States)

    Li, Youxu; Swaisgood, Ronald R; Wei, Wei; Nie, Yonggang; Hu, Yibo; Yang, Xuyu; Gu, Xiaodong; Zhang, Zejun

    2017-04-01

    In response to seasonal variation in quality and quantity of available plant biomass, herbivorous foragers may alternate among different plant resources to meet nutritional requirements. Giant pandas (Ailuropoda melanoleuca) are reliant almost exclusively on bamboo which appears omnipresent in most occupied habitat, but subtle temporal variation in bamboo quality may still govern foraging strategies, with population-level effects. In this paper, we investigated the possibility that temporal variation in the quality of this resource is involved in population regulation and examined pandas' adaptive foraging strategies in response to temporal variation in bamboo quality. Giant pandas in late winter and early spring consumed a less optimal diet in Foping Nature Reserve, as the availability of the most nutritious and preferred components and age classes of Bashania fargesii declined, suggesting that bamboo may be a seasonally limiting resource. Most panda mortalities and rescues occurred during the same period of seasonal food limitation. Our findings raised the possibility that while total bamboo biomass may not be a limiting factor, carrying capacity may be influenced by subtle seasonal variation in bamboo quality. We recommend that managers and policy-makers should consider more than just the quantity of bamboo in the understory and that carrying capacity estimates should be revised downward to reflect the fact that all bamboos are not equal.

  4. Dealing with salinity extremes and nitrogen limitation - an unexpected strategy of the marine bacterium Dinoroseobacter shibae.

    Science.gov (United States)

    Kleist, Sarah; Ulbrich, Marcus; Bill, Nelli; Schmidt-Hohagen, Kerstin; Geffers, Robert; Schomburg, Dietmar

    2017-03-01

    Having the right coping strategy for changes in osmolarity or desiccation is essential for the survival of every cell. So far, nothing is known about compatible solutes and the salt adaptation of the marine Rhodobacteraceae. The family member Dinoroseobacter shibae DFL12(T) is shown here to form the compatible solutes α-glucosylglycerol (GG) and α-glucosylglycerate (GGA). To our knowledge, this is the first experimental evidence for GGA formation within the α-proteobacteria. Together with glutamate and putrescine, these substances enable good growth in salinity ranging from 0.3% to 5%. A salinity of 5% leads to a biomass share of 7.6% of compatible solutes and the very low salt level of 0.3% results in an 18-fold increased putrescine concentration compared with environmental conditions. Additionally, the substitution of glutamate by GGA has been shown during exposure to nitrogen limitation and in the stationary growth phase of the organism. Salt shock transcriptome analysis of D. shibae has revealed the essential role of its 153 kb chromid, which carries the genes for GG biosynthesis and several transport and exchange systems. Within the family of Rhodobacteraceae, the genomic capability of forming GG and GGA is strictly restricted to marine family members.

  5. Unexpected high genetic diversity at the extreme northern geographic limit of Taurulus bubalis (Euphrasen, 1786.

    Directory of Open Access Journals (Sweden)

    Vítor C Almada

    Full Text Available The longspined bullhead (Taurulus bubalis, Euphrasen 1786 belongs to the family Cottidae and is a rocky shore species that inhabits the intertidal zones of the Eastern Atlantic since Iceland, southward to Portugal and also the North Sea and Baltic, northward to the Gulf of Finland, with some occurrences in the northern Mediterranean coasts eastward to the Gulf of Genoa. We analysed the phylogeographic patterns of this species using mitochondrial and nuclear markers in populations throughout most of its distributional range in west Europe. We found that T. bubalis has a relatively shallow genealogy with some differentiation between Atlantic and North Sea. Genetic diversity was homogeneous across all populations studied. The possibility of a glacial refugium near the North Sea is discussed. In many, but not all, marine temperate organisms, patterns of diversity are similar across the species range. If this phenomenon proves to be most common in cold adapted species, it may reflect the availability of glacial refugia not far from their present-day northern limits.

  6. Voice-Activated Lightweight Reacher to Assist with Upper Extremity Movement Limitations: A Case Study.

    Science.gov (United States)

    Khalid, Umer; Conti, Gerry E; Erlandson, Robert F; Ellis, Richard D; Brown, Vince; Pandya, Abhilash K

    2015-01-01

    The focus of this research was to design a functional and user-friendly reacher for people with spinal cord injuries (SCIs). Engineering advancements have taken assistive robotics to new dimensions. Technologies such as wheelchair robotics and myo-electronically controlled systems have opened up a wide range of new applications to assist people with physical disabilities. Similarly, exo-skeletal limbs and body suits have provided new foundations from which technologies can aid function. Unfortunately, these devices have issues of usability, weight, and discomfort with donning. The Smart Assistive Reacher Arm (SARA) system, developed in this research, is a voice-activated, lightweight, mobile device that can be used when needed. SARA was built to help overcome daily reach challenges faced by individuals with limited arm and hand movement capability, such as people with cervical level 5-6 (C5-6) SCI. This article shows that a functional reacher arm with voice control can be beneficial for this population. Comparison study with healthy participants and an SCI participant shows that, when using SARA, a person with SCI can perform simple reach and grasp tasks independently, without someone else's help. This suggests that the interface is intuitive and can be easily used to a high level of proficiency by a SCI individual.

  7. Current strategies for improving access and adherence to antiretroviral therapies in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Scanlon ML

    2013-01-01

    Full Text Available Michael L Scanlon,1,2 Rachel C Vreeman1,21Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA; 2USAID, Academic Model Providing Access to Healthcare (AMPATH Partnership, Eldoret, KenyaAbstract: The rollout of antiretroviral therapy (ART significantly reduced human immunodeficiency virus (HIV-related morbidity and mortality, but good clinical outcomes depend on access and adherence to treatment. In resource-limited settings, where over 90% of the world’s HIV-infected population resides, data on barriers to treatment are emerging that contribute to low rates of uptake in HIV testing, linkage to and retention in HIV care systems, and suboptimal adherence rates to therapy. A review of the literature reveals limited evidence to inform strategies to improve access and adherence with the majority of studies from sub-Saharan Africa. Data from observational studies and randomized controlled trials support home-based, mobile and antenatal care HIV testing, task-shifting from doctor-based to nurse-based and lower level provider care, and adherence support through education, counseling and mobile phone messaging services. Strategies with more limited evidence include targeted HIV testing for couples and family members of ART patients, decentralization of HIV care, including through home- and community-based ART programs, and adherence promotion through peer health workers, treatment supporters, and directly observed therapy. There is little evidence for improving access and adherence among vulnerable groups such as women, children and adolescents, and other high-risk populations and for addressing major barriers. Overall, studies are few in number and suffer from methodological issues. Recommendations for further research include health information technology, social-level factors like HIV stigma, and new research directions in cost-effectiveness, operations, and implementation. Findings from this review make a

  8. Binary black hole coalescence in the extreme-mass-ratio limit: testing and improving the effective-one-body multipolar waveform

    CERN Document Server

    Bernuzzi, Sebastiano; Zenginoglu, Anil

    2010-01-01

    We discuss the properties of the effective-one-body (EOB) multipolar gravitational waveform emitted by nonspinning black-hole binaries of masses $\\mu$ and $M$ in the extreme-mass-ratio limit, $\\mu/M=\

  9. Intelligent self-organization methods for wireless ad hoc sensor networks based on limited resources

    Science.gov (United States)

    Hortos, William S.

    2006-05-01

    A wireless ad hoc sensor network (WSN) is a configuration for area surveillance that affords rapid, flexible deployment in arbitrary threat environments. There is no infrastructure support and sensor nodes communicate with each other only when they are in transmission range. To a greater degree than the terminals found in mobile ad hoc networks (MANETs) for communications, sensor nodes are resource-constrained, with limited computational processing, bandwidth, memory, and power, and are typically unattended once in operation. Consequently, the level of information exchange among nodes, to support any complex adaptive algorithms to establish network connectivity and optimize throughput, not only deplete those limited resources and creates high overhead in narrowband communications, but also increase network vulnerability to eavesdropping by malicious nodes. Cooperation among nodes, critical to the mission of sensor networks, can thus be disrupted by the inappropriate choice of the method for self-organization. Recent published contributions to the self-configuration of ad hoc sensor networks, e.g., self-organizing mapping and swarm intelligence techniques, have been based on the adaptive control of the cross-layer interactions found in MANET protocols to achieve one or more performance objectives: connectivity, intrusion resistance, power control, throughput, and delay. However, few studies have examined the performance of these algorithms when implemented with the limited resources of WSNs. In this paper, self-organization algorithms for the initiation, operation and maintenance of a network topology from a collection of wireless sensor nodes are proposed that improve the performance metrics significant to WSNs. The intelligent algorithm approach emphasizes low computational complexity, energy efficiency and robust adaptation to change, allowing distributed implementation with the actual limited resources of the cooperative nodes of the network. Extensions of the

  10. The functioning of oxygen concentrators in resource-limited settings: a situation assessment in two countries.

    Science.gov (United States)

    La Vincente, S F; Peel, D; Carai, S; Weber, M W; Enarson, P; Maganga, E; Soyolgerel, G; Duke, T

    2011-05-01

    The paediatric wards of hospitals in Malawi and Mongolia. To describe oxygen concentrator functioning in two countries with widespread, long-term use of concentrators as a primary source of oxygen for treating children. A systematic assessment of concentrators in the paediatric wards of 15 hospitals in Malawi and nine hospitals in Mongolia. Oxygen concentrators had been installed for a median of 48 months (interquartile range [IQR] 6-60) and 36 months (IQR 12-96), respectively, prior to the evaluation in Malawi and Mongolia. Concentrators were the primary source of oxygen. Three quarters of the concentrators assessed in Malawi (28/36) and half those assessed in Mongolia (13/25) were functional. Concentrators were found to remain functional with up to 30 000 h of use. However, several concentrators were functioning very poorly despite limited use. Concentrators from a number of different manufacturers were evaluated, and there was marked variation in performance between brands. Inadequate resources for maintenance were reported in both countries. Years after installation of oxygen concentrators, many machines were still functioning, indicating that widespread use can be sustained in resource-limited settings. However, concentrator performance varied substantially. Procurement of high-quality and appropriate equipment is critical, and resources should be made available for ongoing maintenance.

  11. CERN Colloquium: The Effects of Limited Resources and Opportunities on Women’s Careers in Physics

    CERN Multimedia

    2012-01-01

    The Effects of Limited Resources and Opportunities on Women’s Careers in Physics: Results from the Global Survey of Physicists, by Rachel Ivie (American Institute of Physics).   Thursday, May 3, 2012 from 16:30 to 17:30 (Europe/Zurich) at CERN ( 503-1-001 - Council Chamber ) The results of the Global Survey of Physicists draw attention to the need to focus on factors other than representation when discussing the situation of women in physics. Previous studies of women in physics have mostly focused on the lack of women in the field. This study goes beyond the obvious shortage of women and shows that there are much deeper issues. For the first time, a multinational study was conducted with 15000 respondents from 130 countries, showing that problems for women in physics transcend national borders. Across all countries, women have fewer resources and opportunities and are more affected by cultural expectations concerning child care. We show that limited resources and opportunities hurt ca...

  12. An Upper Limit on the Ratio Between the Extreme Ultraviolet and the Bolometric Luminosities of Stars Hosting Habitable Planets

    Indian Academy of Sciences (India)

    Sujan Sengupta

    2016-06-01

    A large number of terrestrial planets in the classical habitable zone of stars of different spectral types have already been discovered and many are expected to be discovered in the near future. However, owing to the lack of knowledge on the atmospheric properties, the ambient environment of such planets are unknown. It is known that sufficient amount of Extreme Ultraviolet (EUV) radiation from the star can drive hydrodynamic outflow of hydrogen that may drag heavier species from the atmosphere of the planet. If the rate of mass loss is sufficiently high, then substantial amount of volatiles would escape causing the planet to become uninhabitable. Considering energy-limited hydrodynamical mass loss with an escape rate that causes oxygen to escape alongwith hydrogen, an upper limit for the ratio between the EUV and the bolometric luminosities of stars which constrains the habitability of planets around them is presented here. Application of the limit to planet-hosting stars with known EUV luminosities implies that many M-type of stars should not have habitable planets around them.

  13. The Oregon health insurance experiment: when limited policy resources provide research opportunities.

    Science.gov (United States)

    Allen, Heidi; Baicker, Katherine; Taubman, Sarah; Wright, Bill; Finkelstein, Amy

    2013-12-01

    In 2008 Oregon allocated access to its Medicaid expansion program, Oregon Health Plan Standard, by drawing names from a waiting list by lottery. The lottery was chosen by policy makers and stakeholders as the preferred way to allocate limited resources. At the same time, it also gave rise to the Oregon Health Insurance Experiment: an unprecedented opportunity to do a randomized evaluation - the gold standard in medical and scientific research - of the impact of expanding Medicaid. In this article we provide historical context for Oregon's decision to conduct a lottery, discuss the importance of randomized controlled designs for policy evaluation, and describe some of the practical challenges in successfully capitalizing on the research opportunity presented by the Oregon lottery through public-academic partnerships. Since policy makers will always face tough choices about how to distribute scarce resources, we urge thoughtful consideration of the opportunities to incorporate randomization that can substantially improve the evidence available to inform policy decisions without compromising policy goals.

  14. A LIMITED RESOURCE VECTOR LOAD-BALANCING ALGORITHM FOR SOFTSWITCH-BASED HETEROGENEOUS CLUSTERED MEDIA SERVER

    Institute of Scientific and Technical Information of China (English)

    Wu Naixing; Liao Jianxin; Zhu Xiaomin

    2006-01-01

    Based on the system feature of softswitch-based heterogeneous clustered media server, this paper proposed a limited resource vector load-balancing algorithm. The purpose of the algorithm was to balance the load of clusters by utilizing all system resources effectively and to avoid violent shaking of the system performance. A lot of simulations on the Petri net model of load balance system are conducted and the algorithm is compared with some traditional algorithms on balancing ability for heterogeneity, system throughput, request response time and performance stability. The results of simulations show that the algorithm achieves system higher performance and it has excellent ability to deal with the heterogeneity of clustered media server.

  15. Upper Extremity Injured Workers Stratified by Current Work Status: An Examination of Health Characteristics, Work Limitations and Work Instability

    Directory of Open Access Journals (Sweden)

    H Grant

    2010-06-01

    Full Text Available Background: Upper extremity injured workers are an under-studied population. A descriptive comparison of workers with shoulder, elbow and hand injuries reporting to a Canadian Workplace Safety and Insurance Board (WSIB clinic was undertaken.Objective: To determine if differences existed between injury groups stratified by current work status.Methods: All WSIB claimants reporting to our upper extremity clinic between 2003 and 2008 were approached to participate in this descriptive study. 314 working and 146 non-working WSIB claimants completed the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH; Short Form health survey (SF36; Worker’s Limitations Questionnaire and the Work Instability Scale. Various parametric and non-parametric analyses were used to assess significant differences between groups on demographic, work and health related variables.Results: Hand, followed by the shoulder and elbow were the most common site of injury. Most non-workers listed their current injury as the reason for being off work, and attempted to return to work once since their injury occurrence. Non-workers and a subset of workers at high risk for work loss showed significantly worse mental functioning. Workers identified physical demands as the most frequent injury-related on the job limitation. 60% of current workers were listed as low risk for work loss on the Work Instability Scale.Conclusions: Poorer mental functioning, being female and sustaining a shoulder injury were risk factors for work instability. Our cohort of injured non-workers were unable to return to work due to their current injury, reinforcing the need to advocate for modified duties, shorter hours and a work environment where stress and injury recurrence is reduced. Future studies examining pre-injury depression as a risk factor for prolonged work absences are warranted.

  16. Building local human resources to implement SLMTA with limited donor funding: The Ghana experience

    Science.gov (United States)

    Nkrumah, Bernard; van der Puije, Beatrice; Bekoe, Veronica; Adukpo, Rowland; Kotey, Nii A.; Yao, Katy; Fonjungo, Peter N.; Luman, Elizabeth T.; Duh, Samuel; Njukeng, Patrick A.; Addo, Nii A.; Khan, Fazle N.; Woodfill, Celia J.I.

    2016-01-01

    Background In 2009, Ghana adopted the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme in order to improve laboratory quality. The programme was implemented successfully with limited donor funding and local human resources. Objectives To demonstrate how Ghana, which received very limited PEPFAR funding, was able to achieve marked quality improvement using local human resources. Method Local partners led the SLMTA implementation and local mentors were embedded in each laboratory. An in-country training-of-trainers workshop was conducted in order to increase the pool of local SLMTA implementers. Three laboratory cohorts were enrolled in SLMTA in 2011, 2012 and 2013. Participants from each cohort attended in a series of three workshops interspersed with improvement projects and mentorship. Supplemental training on internal audit was provided. Baseline, exit and follow-up audits were conducted using the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA) checklist. In November 2013, four laboratories underwent official SLIPTA audits by the African Society for Laboratory Medicine (ASLM). Results The local SLMTA team successfully implemented three cohorts of SLMTA in 15 laboratories. Seven out of the nine laboratories that underwent follow-up audits have reached at least one star. Three out of the four laboratories that underwent official ASLM audits were awarded four stars. Patient satisfaction increased from 25% to 70% and sample rejection rates decreased from 32% to 10%. On average, $40 000 was spent per laboratory to cover mentors' salaries, SLMTA training and improvement project support. Conclusion Building in-country capacity through local partners is a sustainable model for improving service quality in resource-constrained countries such as Ghana. Such models promote country ownership, capacity building and the use of local human resources for the expansion of SLMTA. PMID:26937417

  17. Building local human resources to implement SLMTA with limited donor funding: The Ghana experience

    Directory of Open Access Journals (Sweden)

    Bernard Nkrumah

    2014-09-01

    Full Text Available Background: In 2009, Ghana adopted the Strengthening Laboratory Management Toward Accreditation (SLMTA programme in order to improve laboratory quality. The programme was implemented successfully with limited donor funding and local human resources.Objectives: To demonstrate how Ghana, which received very limited PEPFAR funding, was able to achieve marked quality improvement using local human resources.Method: Local partners led the SLMTA implementation and local mentors were embedded in each laboratory. An in-country training-of-trainers workshop was conducted in order to increase the pool of local SLMTA implementers. Three laboratory cohorts were enrolled in SLMTA in 2011, 2012 and 2013. Participants from each cohort attended in a series of three workshops interspersed with improvement projects and mentorship. Supplemental trainingon internal audit was provided. Baseline, exit and follow-up audits were conducted using the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA checklist. In November 2013, four laboratories underwent official SLIPTA audits by the African Society for Laboratory Medicine (ASLM.Results: The local SLMTA team successfully implemented three cohorts of SLMTA in 15 laboratories. Seven out of the nine laboratories that underwent follow-up audits have reached at least one star. Three out of the four laboratories that underwent official ASLM audits were awarded four stars. Patient satisfaction increased from 25% to 70% and sample rejection rates decreased from 32% to 10%. On average, $40 000 was spent per laboratory to cover mentors’salaries, SLMTA training and improvement project support.Conclusion: Building in-country capacity through local partners is a sustainable model for improving service quality in resource-constrained countries such as Ghana. Such modelspromote country ownership, capacity building and the use of local human resources for the expansion of SLMTA.

  18. Estimating health workforce needs for antiretroviral therapy in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Fullem Andrew

    2006-01-01

    Full Text Available Abstract Background Efforts to increase access to life-saving treatment, including antiretroviral therapy (ART, for people living with HIV/AIDS in resource-limited settings has been the growing focus of international efforts. One of the greatest challenges to scaling up will be the limited supply of adequately trained human resources for health, including doctors, nurses, pharmacists and other skilled providers. As national treatment programmes are planned, better estimates of human resource needs and improved approaches to assessing the impact of different staffing models are critically needed. However there have been few systematic assessments of staffing patterns in existing programmes or of the estimates being used in planning larger programmes. Methods We reviewed the published literature and selected plans and scaling-up proposals, interviewed experts and collected data on staffing patterns at existing treatment sites through a structured survey and site visits. Results We found a wide range of staffing patterns and patient-provider ratios in existing and planned treatment programmes. Many factors influenced health workforce needs, including task assignments, delivery models, other staff responsibilities and programme size. Overall, the number of health care workers required to provide ART to 1000 patients included 1–2 physicians, 2–7 nurses, Discussion These data are consistent with other estimates of human resource requirements for antiretroviral therapy, but highlight the considerable variability of current staffing models and the importance of a broad range of factors in determining personnel needs. Few outcome or cost data are currently available to assess the effectiveness and efficiency of different staffing models, and it will be important to develop improved methods for gathering this information as treatment programmes are scaled up.

  19. Natural Conception May Be an Acceptable Option in HIV-Serodiscordant Couples in Resource Limited Settings.

    Directory of Open Access Journals (Sweden)

    Lijun Sun

    Full Text Available Many HIV serodiscordant couples have a strong desire to have their own biological children. Natural conception may be the only choice in some resource limited settings but data about natural conception is limited. Here, we reported our findings of natural conception in HIV serodiscordant couples. Between January 2008 and June 2014, we retrospectively collected data on 91 HIV serodiscordant couples presenting to Beijing Youan Hospital with childbearing desires. HIV counseling, effective ART on HIV infected partners, pre-exposure prophylaxis (PrEP and post-exposure prophylaxis (PEP in negative female partners and timed intercourse were used to maximally reduce the risk of HIV transmission. Of the 91 HIV serodiscordant couples, 43 were positive in male partners and 48 were positive in female partners. There were 196 unprotected vaginal intercourses, 100 natural conception and 97 newborns. There were no cases of HIV seroconversion in uninfected sexual partners. Natural conception may be an acceptable option in HIV-serodiscordant couples in resource limited settings if HIV-positive individuals have undetectable viremia on HAART, combined with HIV counseling, PrEP, PEP and timed intercourse.

  20. Management of Epilepsy in Resource-Limited Areas: Establishing an Epilepsy Surgery Program in Iran

    Science.gov (United States)

    Asadi-Pooya, Ali A; Ashjazadeh, Nahid; Kamgarpour, Ahmad; Taghipour, Mousa; Rakei, Seyed Mohamad; Farazdaghi, Mohsen; Inaloo, Soroor; Bagheri, Mohammad Hadi; Razmkon, Ali; Zare, Zahra

    2014-01-01

    Background Of about 40 million people with epilepsy, who live in developing countries, the majority do not receive appropriate treatment. Nonetheless, there are striking disparities among the so-called developing countries, however generally speaking, access to and availability of epilepsy management programs in developing countries are very limited and therefore, the issue of developing epilepsy centers in resource-limited settings in a large scale is very essential. The surgery for epilepsy, including temporal lobotomy, lesionectomy and corpus colostomy, for patients with medically-refractory seizures, defined as failure of adequate trials of two tolerated, appropriately chosen and using antiepileptic drug to achieve sustained freedom, from seizure has been proved to be feasible and cost-effective in developing countries. However, the success of epilepsy surgery depends upon the accurate identification of good surgical candidates based on the available resources and technologies without jeopardizing safety. In the current paper, we will share our experiences of establishing an epilepsy surgery program in Iran, despite all short-comings and limitations and try to provide some answers to those challenges, which helped us establish our program. PMID:25250284

  1. Natural Conception May Be an Acceptable Option in HIV-Serodiscordant Couples in Resource Limited Settings.

    Science.gov (United States)

    Sun, Lijun; Wang, Fang; Liu, An; Xin, Ruolei; Zhu, Yunxia; Li, Jianwei; Shao, Ying; Ye, Jiangzhu; Chen, Danqing; Li, Zaicun

    2015-01-01

    Many HIV serodiscordant couples have a strong desire to have their own biological children. Natural conception may be the only choice in some resource limited settings but data about natural conception is limited. Here, we reported our findings of natural conception in HIV serodiscordant couples. Between January 2008 and June 2014, we retrospectively collected data on 91 HIV serodiscordant couples presenting to Beijing Youan Hospital with childbearing desires. HIV counseling, effective ART on HIV infected partners, pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) in negative female partners and timed intercourse were used to maximally reduce the risk of HIV transmission. Of the 91 HIV serodiscordant couples, 43 were positive in male partners and 48 were positive in female partners. There were 196 unprotected vaginal intercourses, 100 natural conception and 97 newborns. There were no cases of HIV seroconversion in uninfected sexual partners. Natural conception may be an acceptable option in HIV-serodiscordant couples in resource limited settings if HIV-positive individuals have undetectable viremia on HAART, combined with HIV counseling, PrEP, PEP and timed intercourse.

  2. Resource Discovery for Extreme Scale Collaboration (RDESC) Final Report - RPI/TWC - Year 3

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Peter [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2015-05-30

    The amount of data produced in the practice of science is growing rapidly. Despite the accumulation and demand for scientific data, relatively little is actually made available for the broader scientific community. We surmise that the root of the problem is the perceived difficulty to electronically publish scientific data and associated metadata in a way that makes it discoverable. We propose to exploit Semantic Web technologies and practices to make (meta)data discoverable and easy to publish. We share our experiences in curating metadata to illustrate both the flexibility of our approach and the pain of discovering data in the current research environment. We also make recommendations by concrete example of how data publishers can provide their (meta)data by adding some limited, additional markup to HTML pages on the Web. With little additional effort from data publishers, the difficulty of data discovery/access/sharing can be greatly reduced and the impact of research data greatly enhanced.

  3. Nest-site limitation and nesting resources of ants (Hymenoptera: Formicidae) in urban green spaces.

    Science.gov (United States)

    Friedrich, Russell; Philpott, Stacy M

    2009-06-01

    Urbanization impacts biodiversity, yet few studies examine general impacts of urbanization on insects. Furthermore, few studies examine availability and limitation of potential cavity nesting sites for ants, an important regulating factor in ant communities that may vary in different urban habitats. We compared three urban habitat types (gardens, vacant lots, and forests) in Toledo, OH, to examine availability and ant preferences for different cavity nesting resources (small and large hollow twigs and cavities). We added 72 artificial large hollow twigs (83 by 6 mm), small hollow twigs (140 by 2 mm), and spherical hollow cavities (6.52-31.1 cm(3) in volume, 1-mm opening) to six sites from May to August 2007 to determine whether nest-site limitation impacts ant communities. We collected natural nests to compare natural abundance and occupancy of cavity nests in different urban habitats. We opened artificial and natural nests to calculate the percentage occupied by cavity-nesting ants. Across all habitats, small twigs represented 81.1% of natural nests, spherical nests represented 10.1%, and large twigs 8.2%. Ants occupied 8.1% of natural large twigs, 14.6% of cavities, and 4.1% of small twigs. For artificial nests, 21.5% of large twigs, 1% of small twigs, and 1% of spheres were occupied. The high percentage of occupied artificial large twigs could imply this is a preferred and limiting resource in urban habitats. The results show that certain types of nesting resources may be an important factor mediating ant communities in urban green spaces.

  4. Hopf Bifurcation of a Delayed Epidemic Model with Information Variable and Limited Medical Resources

    Directory of Open Access Journals (Sweden)

    Caijuan Yan

    2014-01-01

    Full Text Available We consider SIR epidemic model in which population growth is subject to logistic growth in absence of disease. We get the condition for Hopf bifurcation of a delayed epidemic model with information variable and limited medical resources. By analyzing the corresponding characteristic equations, the local stability of an endemic equilibrium and a disease-free equilibrium is discussed. If the basic reproduction ratio ℛ01, we obtain sufficient conditions under which the endemic equilibrium E* of system is locally asymptotically stable. And we also have discussed the stability and direction of Hopf bifurcations. Numerical simulations are carried out to explain the mathematical conclusions.

  5. Visuo-spatialWorking Memory as a Limited Resource of Cognitive Processing

    Science.gov (United States)

    Zimmer, Hubert D.; Münzer, Stefan; Umla-Runge, Katja

    Working memory is considered a cognitive component that mainly serves two functions. It temporarily maintains information that was either perceived but is no longer present in the environment, or that was internally generated, and it supplies a work space for transforming and manipulating elements of perception and thinking. Both functions are relevant for a successful interaction with the environment and it is therefore not surprising that WM is a central topic of research in the field of general psychology. This interest is further increased by the fact that WM is seen as a limited resource that constrains cognitive performances.

  6. Overcoming limits set by scarce resources - role of local food production and food imports

    Science.gov (United States)

    Porkka, Miina; Guillaume, Joseph H. A.; Schaphoff, Sibyll; Siebert, Stefan; Gerten, Dieter; Kummu, Matti

    2017-04-01

    There is a fundamental tension between population growth and carrying capacity, i.e. the population that could potentially be supported using the resources and technologies available at a given time. This makes the assessments of resource use and agricultural productivity central to the debate on future food security. Local carrying capacity can be increased by expanding (e.g. through land conversion and irrigation infrastructure) or intensifying (e.g. through technologies and practices that increase efficiency) the resource use in agriculture. Food imports can be considered another way of overcoming current local limits and continuing growth beyond the local human-carrying capacity. Focusing on water as the key limiting resource, we performed a global assessment of the capacity for food self-sufficiency at sub-national and national scale for 1961-2009, taking into account the availability of both green and blue water as well as technology and management practices affecting water productivity at a given time, and using the hydrology and agriculture model LPJmL as our primary tool. Furthermore, we examined the use of food imports as a strategy to increase carrying capacity in regions where the potential for food self-sufficiency was limited by water availability and productivity. We found that the capacity for food self-sufficiency reduced notably during the study period due to the rapid population growth that outpaced the substantial improvements in water productivity. In 2009 more than a third (2.2 billion people) of the world's population lived in areas where sufficient food production to meet the needs of the population was not possible, and some 800 million people more were approaching this threshold. Food imports have nearly universally been used to overcome these local limits to growth, though the success of this strategy has been highly dependent on economic purchasing power. In the unsuccessful cases, increases in imports and local productivity have not

  7. Spontaneous oesophageal rupture: a diagnostic challenge in resource-limited setting.

    Science.gov (United States)

    Shao, Elichilia R; Joseph, Pantaleo M; Slootweg, Piet; Mkwizu, Elifuraha W; Kilonzo, Kajiru G; Mwasamwaja, Amos O

    2015-08-01

    Spontaneous oesophageal rupture after swallowing a bolus of food is a very rare condition. In resource-limited settings, it is very challenging to diagnose this condition especially when its presentation is atypical. Its prognosis is very poor when diagnosis is delayed due to risk of mediastinitis. We report a case of 37-year-old man who was admitted to our hospital complaining of sudden onset of chest tightness and pain after a meal 8 h prior to admission. Urgent chest radiograph revealed right hydropneumothorax with collapsed lung. Water-seal drainage was established gushing 1200 ml of food materials. Definitive diagnosis of oesophageal rupture was reached after post-mortem.

  8. Diagnostic challenges of sexually transmitted infections in resource-limited settings.

    Science.gov (United States)

    Peeling, Rosanna W; Ronald, Allan

    2009-12-01

    The global burden of sexually transmitted infections (STIs) is highest in the developing world where access to laboratory services is limited. Sophisticated laboratory diagnostic tests using noninvasive specimens have enabled developed countries to screen and diagnose curable STIs in a variety of settings, but control programs in resource-limited settings continue to struggle to find simple rapid tests that can provide adequate performance in the absence of laboratory services. While recent technological advances and investments in research and development may soon yield improved STI tests that can make an impact, these tests will need to be deployed within a health system that includes: regulatory oversight, quality assurance, good supply-chain management, effective training, information systems and a sound surveillance system to monitor disease trends, inform policy decisions and assess the impact of interventions.

  9. Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

    Science.gov (United States)

    Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

    2016-01-01

    Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

  10. The maintenance of cooperation in multiplex networks with limited and partible resources of agents

    Science.gov (United States)

    Li, Zhaofeng; Shen, Bi; Jiang, Yichuan

    2017-02-01

    In this paper, we try to explain the maintenance of cooperation in multiplex networks with limited and partible resources of agents: defection brings larger short-term benefit and cooperative agents may become defective because of the unaffordable costs of cooperative behaviors that are performed in multiple layers simultaneously. Recent studies have identified the positive effects of multiple layers on evolutionary cooperation but generally overlook the maximum costs of agents in these synchronous games. By utilizing network effects and designing evolutionary mechanisms, cooperative behaviors become prevailing in public goods games, and agents can allocate personal resources across multiple layers. First, we generalize degree diversity into multiplex networks to improve the prospect for cooperation. Second, to prevent agents allocating all the resources into one layer, a greedy-first mechanism is proposed, in which agents prefer to add additional investments in the higher-payoff layer. It is found that greedy-first agents can perform cooperative behaviors in multiplex networks when one layer is scale-free network and degree differences between conjoint nodes increase. Our work may help to explain the emergence of cooperation in the absence of individual reputation and punishment mechanisms.

  11. Multi sensor fusion framework for indoor-outdoor localization of limited resource mobile robots.

    Science.gov (United States)

    Marín, Leonardo; Vallés, Marina; Soriano, Ángel; Valera, Ángel; Albertos, Pedro

    2013-10-21

    This paper presents a sensor fusion framework that improves the localization of mobile robots with limited computational resources. It employs an event based Kalman Filter to combine the measurements of a global sensor and an inertial measurement unit (IMU) on an event based schedule, using fewer resources (execution time and bandwidth) but with similar performance when compared to the traditional methods. The event is defined to reflect the necessity of the global information, when the estimation error covariance exceeds a predefined limit. The proposed experimental platforms are based on the LEGO Mindstorm NXT, and consist of a differential wheel mobile robot navigating indoors with a zenithal camera as global sensor, and an Ackermann steering mobile robot navigating outdoors with a SBG Systems GPS accessed through an IGEP board that also serves as datalogger. The IMU in both robots is built using the NXT motor encoders along with one gyroscope, one compass and two accelerometers from Hitecnic, placed according to a particle based dynamic model of the robots. The tests performed reflect the correct performance and low execution time of the proposed framework. The robustness and stability is observed during a long walk test in both indoors and outdoors environments.

  12. Enhanced recovery protocol: implementation at a county institution with limited resources.

    Science.gov (United States)

    Rona, Kais; Choi, J; Sigle, G; Kidd, S; Ault, G; Senagore, A J

    2012-10-01

    The benefits of an enhanced recovery protocol (ERP) in colorectal surgery have been well described; however, data on the implementation process is minimal, especially in a resource-limited institution. The purpose of this study was to evaluate outcomes during implementation of a physician-driven ERP at a public-funded institution. We retrospectively reviewed all elective colorectal surgery during a transition from standard care to an ERP (implemented via a standard order sheet). Data regarding use of care plan, length of stay (LOS), and rates of postoperative complications and readmission were recorded. One hundred eleven patients were included in the study; however, complete use of the ERP after its introduction occurred in a total of 50 patients for a compliance rate of 60 per cent (95% confidence interval [CI], 49 to 70). Late implementation of ERP diet, analgesics, and activity were the most common process errors. Full application of the ERP reduced mean LOS by 3 days (P=0.002), and there was a trend toward decreased postoperative morbidity without an increase in readmission rate (P=0.61). Full implementation of an ERP for colorectal surgery faces many challenges in a resource-limited county institution; however, when fully applied, the ERP safely reduced overall LOS, which is important in cost containment.

  13. Evaluating Diagnostic Point-of-Care Tests in Resource-Limited Settings

    Science.gov (United States)

    Drain, Paul K; Hyle, Emily P; Noubary, Farzad; Freedberg, Kenneth A; Wilson, Douglas; Bishai, William; Rodriguez, William; Bassett, Ingrid V

    2014-01-01

    Diagnostic point-of-care (POC) testing is intended to minimize the time to obtain a test result, thereby allowing clinicians and patients to make an expeditious clinical decision. As POC tests expand into resource-limited settings (RLS), the benefits must outweigh the costs. To optimize POC testing in RLS, diagnostic POC tests need rigorous evaluations focused on relevant clinical outcomes and operational costs, which differ from evaluations of conventional diagnostic tests. Here, we reviewed published studies on POC testing in RLS, and found no clearly defined metric for the clinical utility of POC testing. Therefore, we propose a framework for evaluating POC tests, and suggest and define the term “test efficacy” to describe a diagnostic test’s capacity to support a clinical decision within its operational context. We also proposed revised criteria for an ideal diagnostic POC test in resource-limited settings. Through systematic evaluations, comparisons between centralized diagnostic testing and novel POC technologies can be more formalized, and health officials can better determine which POC technologies represent valuable additions to their clinical programs. PMID:24332389

  14. A point-of-care PCR test for HIV-1 detection in resource-limited settings.

    Science.gov (United States)

    Jangam, Sujit R; Agarwal, Abhishek K; Sur, Kunal; Kelso, David M

    2013-04-15

    A low-cost, fully integrated sample-to-answer, quantitative PCR (qPCR) system that can be used for detection of HIV-1 proviral DNA in infants at the point-of-care in resource-limited settings has been developed and tested. The system is based on a novel DNA extraction method, which uses a glass fiber membrane, a disposable assay card that includes on-board reagent storage, provisions for thermal cycling and fluorescence detection, and a battery-operated portable analyzer. The system is capable of automated PCR mix assembly using a novel reagent delivery system and performing qPCR. HIV-1 and internal control targets are detected using two spectrally separated fluorophores, FAM and Quasar 670. In this report, a proof-of-concept of the platform is demonstrated. Initial results with whole blood demonstrate that the test is capable of detecting HIV-1 in blood samples containing greater than 5000 copies of HIV-1. In resource-limited settings, a point-of-care HIV-1 qPCR test would greatly increase the number of test results that reach the infants caregivers, allowing them to pursue anti-retroviral therapy.

  15. Multi Sensor Fusion Framework for Indoor-Outdoor Localization of Limited Resource Mobile Robots

    Directory of Open Access Journals (Sweden)

    Pedro Albertos

    2013-10-01

    Full Text Available This paper presents a sensor fusion framework that improves the localization of mobile robots with limited computational resources. It employs an event based Kalman Filter to combine the measurements of a global sensor and an inertial measurement unit (IMU on an event based schedule, using fewer resources (execution time and bandwidth but with similar performance when compared to the traditional methods. The event is defined to reflect the necessity of the global information, when the estimation error covariance exceeds a predefined limit. The proposed experimental platforms are based on the LEGO Mindstorm NXT, and consist of a differential wheel mobile robot navigating indoors with a zenithal camera as global sensor, and an Ackermann steering mobile robot navigating outdoors with a SBG Systems GPS accessed through an IGEP board that also serves as datalogger. The IMU in both robots is built using the NXT motor encoders along with one gyroscope, one compass and two accelerometers from Hitecnic, placed according to a particle based dynamic model of the robots. The tests performed reflect the correct performance and low execution time of the proposed framework. The robustness and stability is observed during a long walk test in both indoors and outdoors environments.

  16. Diagnostic and Treatment Difficulties of Pyelonephritis in Pregnancy in Resource-Limited Settings

    Science.gov (United States)

    McGready, Rose; Wuthiekanun, Vanaporn; Ashley, Elizabeth A.; Tan, Saw Oo; Pimanpanarak, Mupawjay; Viladpai-nguen, Samuel Jacher; Jesadapanpong, Wilarat; Blacksell, Stuart D.; Proux, Stephane; Day, Nicholas P.; Singhasivanon, Pratap; White, Nicholas J.; Nosten, François; Peacock, Sharon J.

    2010-01-01

    Limited microbiology services impede adequate diagnosis and treatment of common infections such as pyelonephritis in resource-limited settings. Febrile pregnant women attending antenatal clinics at Shoklo Malaria Research Unit were offered urine dipstick, sediment microscopy, urine culture, and a 5-mL blood culture. The incidence of pyelonephritis was 11/1,000 deliveries (N = 53 in 4,819 pregnancies) between January 7, 2004 and May 17, 2006. Pyelonephritis accounted for 20.2% (41/203) of fever cases in pregnancy. Escherichia coli was the most commonly isolated pathogen: 87.5% (28/32) of organisms cultured. Susceptibility of E. coli to ampicillin (14%), cotrimoxazole (21%), and amoxicillin-clavulanic acid (48%) was very low. E. coli was susceptible to ceftriaxone and ciprofloxacin. The rate of extended spectrum β-lactamase (4.2%; 95% confidence interval = 0.7–19.5) was low. The rate and causes of pyelonephritis in pregnant refugee and migrant women were comparable with those described in developed countries. Diagnostic innovation in microbiology that permits affordable access is a high priority for resource-poor settings. PMID:21118943

  17. The benefits of international rotations to resource-limited settings for U.S. surgery residents.

    Science.gov (United States)

    Henry, Jaymie A; Groen, Reinou S; Price, Raymond R; Nwomeh, Benedict C; Kingham, T Peter; Hardy, Mark A; Kushner, Adam L

    2013-04-01

    U.S. surgery residents increasingly are interested in international experiences. Recently, the Residency Review Committee approved international surgery rotations for credit toward graduation. Despite this growing interest, few U.S. surgery residency programs offer formal international rotations. We aimed to present the benefits of international surgery rotations and how these rotations contribute to the attainment of the 6 Accreditation Council for Graduate Medical Education (ACGME) competencies. An e-mail-based survey was sent in November 2011 to the 188 members of Surgeons OverSeas, a group of surgeons, residents, fellows, and medical students with experience working in resource-limited settings. They were asked to list 5 benefits of international rotations for surgery residents. The frequency of benefits was qualitatively grouped into 4 major categories: educational, personal, benefits to the foreign institution/Global Surgery, and benefits to the home institution. The themes were correlated with the 6 ACGME competencies. The 58 respondents (31% response rate) provided a total of 295 responses. Fifty themes were identified. Top benefits included learning to optimally function with limited resources, exposure to a wide variety of operative pathology, exposure to a foreign culture, and forming relationships with local counterparts. All ACGME competencies were covered by the themes. International surgery rotations to locations in which resources are constrained, operative diseases vary, and patient diversity abound provide unique opportunities for surgery residents to attain the 6 ACGME competencies. General surgery residency programs should be encouraged to establish formal international rotations as part of surgery training to promote resident education and assist with necessary oversight. Copyright © 2013 Mosby, Inc. All rights reserved.

  18. FORMATION A STRATEGY OF SOCIOECONOMIC SYSTEM’S DEVELOPMENT IN THE RESOURCE-LIMITED CONDITIONS

    Directory of Open Access Journals (Sweden)

    Lukyanenko T. V.

    2015-06-01

    Full Text Available In the article the structural model of the socio-economic system is presented as a management object. We have described the levels of creation of mathematical estimation model of the socio-economic system’s state, which on the basis of the aggregated estimation of management factors array allows selecting the primary purposes of socio-economic system’s development. The main socio-economic system’s processes in the production of goods and services are presented as complex activities. Determining methods for the modern market share occupied by socio-economic system, socio-economic system’s actual share offers on the region market, the demand for goods and services in the region, the amount of income from the activity by mathematical estimation model of the socio-economic system’s state are offered. The amount of the budget is defined as the sum of the socio-economic system profits from commercial activities and the size of public funding on the orders. Evaluation of resource support for activities described in the article is proposed. The way to solve the actual problem management - determining the socio-economic system’s priorities with limited material and financial resources is offered. We have also presented an algorithm of determination of aims of the development on the basis of estimation model of the socio-economic system’s state, foreseeing determination of external and internal factors on directions activity and forming of their aggregated estimations. The operative management in a socio-economic system allows us to react immediately to changing of key indexes of the systems and also allows using the limited resources rationally, which is very actual in modern economic conditions

  19. Limited resources of genome sequencing in developing countries: Challenges and solutions

    Directory of Open Access Journals (Sweden)

    Mohamed Helmy

    2016-06-01

    Full Text Available The differences between countries in national income, growth, human development and many other factors are used to classify countries into developed and developing countries. There are several classification systems that use different sets of measures and criteria. The most common classifications are the United Nations (UN and the World Bank (WB systems. The UN classification system uses the UN Human Development Index (HDI, an indicator that uses statistic of life expectancy, education, and income per capita for countries' classification. While the WB system uses gross national income (GNI per capita that is calculated using the World Bank Atlas method. According to the UN and WB classification systems, there are 151 and 134 developing countries, respectively, with 89% overlap between the two systems. Developing countries have limited human development, and limited expenditure in education and research, among several other limitations. The biggest challenge facing genomic researchers and clinicians is limited resources. As a result, genomic tools, specifically genome sequencing technologies, which are rapidly becoming indispensable, are not widely available. In this report, we explore the current status of sequencing technologies in developing countries, describe the associated challenges and emphasize potential solutions.

  20. Limited resources of genome sequencing in developing countries: Challenges and solutions.

    Science.gov (United States)

    Helmy, Mohamed; Awad, Mohamed; Mosa, Kareem A

    2016-06-01

    The differences between countries in national income, growth, human development and many other factors are used to classify countries into developed and developing countries. There are several classification systems that use different sets of measures and criteria. The most common classifications are the United Nations (UN) and the World Bank (WB) systems. The UN classification system uses the UN Human Development Index (HDI), an indicator that uses statistic of life expectancy, education, and income per capita for countries' classification. While the WB system uses gross national income (GNI) per capita that is calculated using the World Bank Atlas method. According to the UN and WB classification systems, there are 151 and 134 developing countries, respectively, with 89% overlap between the two systems. Developing countries have limited human development, and limited expenditure in education and research, among several other limitations. The biggest challenge facing genomic researchers and clinicians is limited resources. As a result, genomic tools, specifically genome sequencing technologies, which are rapidly becoming indispensable, are not widely available. In this report, we explore the current status of sequencing technologies in developing countries, describe the associated challenges and emphasize potential solutions.

  1. HIV/AIDS and lipodystrophy: Implications for clinical management in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Julia L Finkelstein

    2015-01-01

    Full Text Available Introduction: Lipodystrophy is a term used to describe a metabolic complication of fat loss, fat gain, or a combination of fat loss and gain, which is associated with some antiretroviral (ARV therapies given to HIV-infected individuals. There is limited research on lipodystrophy in low- and middle-income countries, despite accounting for more than 95% of the burden of HIV/AIDS. The objective of this review was to evaluate the prevalence, pathogenesis and prognosis of HIV-related lipoatrophy, lipohypertrophy and mixed syndrome, to inform clinical management in resource-limited settings. Methods: We conducted a structured literature search using MEDLINE electronic databases. Relevant MeSH terms were used to identify published human studies on HIV and lipoatrophy, lipohypertrophy, or mixed syndrome in low-, low-middle- and upper-middle-income countries through 31 March 2014. The search resulted in 5296 articles; after 1599 studies were excluded (958 reviews, 641 non-human, 3697 studies were extracted for further review. After excluding studies conducted in high-income settings (n=2808, and studies that did not meet inclusion criteria (n=799, 90 studies were included in this review. Results and Discussion: Of the 90 studies included in this review, only six were from low-income countries and eight were from lower middle-income economies. These studies focused on lipodystrophy prevalence, risk factors and side effects of antiretroviral therapy (ART. In most studies, lipodystrophy developed after the first six months of therapy, particularly with the use of stavudine. Lipodystrophy is associated with increased risk of cardiometabolic complications. This is disconcerting and anticipated to increase, given the rapid scale-up of ART worldwide, the increasing number and lifespan of HIV-infected patients on long-term therapy, and the emergence of obesity and non-communicable diseases in settings with extensive HIV burden. Conclusions: Lipodystrophy is

  2. Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Alemseged Abdissa

    2014-06-01

    Full Text Available Introduction: Therapeutic drug monitoring (TDM may improve antiretroviral efficacy through adjustment of individual drug administration. This could result in reduced toxicity, prevent drug resistance, and aid management of drug–drug interactions. However, most measurement methods are too costly to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods: The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations measured by the immunoassay with liquid chromatography tandem mass spectrometry (LC-MS/MS (reference method in 315 plasma samples collected from HIV patients on treatment. Concentrations were categorized as suboptimal4 µg/ml. Agreement between results of the methods was assessed via Bland-Altman plot and κ statistic values. Results: The median Interquartile range (IQR efavirenz concentration was 2.8 (1.9; 4.5 µg/ml measured by the LC–MS/MS method and 2.5 (1.8; 3.9 µg/ml by the immunoassay and the results were well correlated (ρ=0.94. The limits of agreement assessed by Bland–Altman plots were −2.54; 1.70 µg/ml. Although immunoassay underestimated high concentrations, it had good agreement for classification into low, normal or high concentrations (K=0.74. Conclusions: The immunoassay is a feasible alternative to determine efavirenz in areas with limited resources. The assay provides a reasonable approximation of efavirenz concentration in the majority of samples with a tendency to underestimate high concentrations. Agreement between tests evaluated in this study was clinically satisfactory for identification of low, normal and high efavirenz concentrations.

  3. Risk factors for mortality during antiretroviral therapy in older populations in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Daniel O’Brien

    2016-01-01

    Full Text Available Introduction: An increasing proportion of adult patients initiating antiretroviral therapy (ART in resource-limited settings are aged >50 years. Older populations on ART appear to have heightened risk of death, but little is known about factors influencing mortality in this population. Methods: We performed a retrospective observational multisite cohort study including all adult patients (≥15 years initiating ART between 2003 and 2013 in programmes supported by Médecins Sans Frontières across 12 countries in Asia, Africa and Europe. Patients were stratified into two age groups, >50 years and 15 to 50 years. A Cox proportional hazards model was used to explore factors associated with mortality. Results: The study included 41,088 patients: 2591 (6.3% were aged >50 years and 38,497 (93.7% were aged 15 to 50 years. The mortality rate was significantly higher in the age group >50 years [367 (14.2% deaths; mortality rate 7.67 deaths per 100 person-years (95% confidence interval, CI: 6.93 to 8.50] compared to the age group 15 to 50 years [3788 (9.8% deaths; mortality rate 4.18 deaths per 100 person-years (95% CI: 4.05 to 4.31], p50 age group. WHO Stage 4 conditions were more strongly associated with increased mortality rates in the 15 to 50 age group compared to populations >50 years. WHO Stage 3 conditions were associated with an increased mortality rate in the 15 to 50 age group but not in the >50 age group. Programme region did not affect mortality rates in the >50 age group; however being in an Asian programme was associated with a 36% reduced mortality rate in populations aged 15 to 50 years compared to being in an African programme. There was a higher overall incidence of Stage 3 WHO conditions in people >50 years (12.8/100 person-years compared to those 15 to 50 years (8.1/100 person-years (p50 age groups. Conclusions: Older patients on ART in resource-limited settings have increased mortality rates, but compared to younger populations this

  4. Emergency vaccination of rabies under limited resources – combating or containing?

    Directory of Open Access Journals (Sweden)

    Selhorst Thomas

    2005-03-01

    Full Text Available Abstract Background Rabies is the most important viral zoonosis from a global perspective. Worldwide efforts to combat the disease by oral vaccination of reservoirs have managed to eradicate wildlife rabies in large areas of central Europe and North-America. Thus, repeated vaccination has been discontinued recently on a geographical scale. However, as rabies has not yet been eradicated globally, a serious risk of re-introduction remains. What is the best spatial design for an emergency vaccination program – particularly if resources are limited? Either, we treat a circular area around the detected case and run the risk of infected hosts leaving the limited control area, because a sufficient immunisation level has not yet been built up. Or, initially concentrate the SAME resources in order to establish a protective ring which is more distant from the infected local area, and which then holds out against the challenge of the approaching epidemic. Methods We developed a simulation model to contrast the two strategies for emergency vaccination. The spatial-explicit model is based on fox group home-ranges, which facilitates the simulation of rabies spread to larger areas relevant to management. We used individual-based fox groups to follow up the effects of vaccination in a detailed manner. Thus, regionally – bait distribution orientates itself to standard schemes of oral immunisation programs and locally – baits are assigned to individual foxes. Results Surprisingly, putting the controlled area ring-like around the outbreak does not outperform the circular area of the same size centred on the outbreak. Only during the very first baitings, does the ring area result in fewer breakouts. But then as rabies is eliminated within the circle area, the respective ring area fails, due to the non-controlled inner part. We attempt to take advantage of the initially fewer breakouts beyond the ring when applying a mixed strategy. Therefore, after a certain

  5. Equity of access to reproductive health services among youths in resource-limited suburban communities of Mandalay City, Myanmar

    National Research Council Canada - National Science Library

    Thin Zaw, Phyu Phyu; Liabsuetrakul, Tippawan; Htay, Thien Thien; McNeil, Edward

    2012-01-01

    .... This study aimed to assess baseline information on access to and utilization of RH services and unmet needs among youths living in resource-limited, suburban communities of Mandalay City, Myanmar...

  6. Identification of Barriers to Pediatric Care in Limited-Resource Settings: A Simulation Study.

    Science.gov (United States)

    Shilkofski, Nicole; Hunt, Elizabeth A

    2015-12-01

    Eighty percent of the 10 million annual deaths in children aged education for pediatric emergency management being a key factor. Education must take into account cultural considerations to be effective. Study objectives were: (1) to use simulation to identify factors posing barriers to patient care in limited resource settings (LRS); and (2) to understand how simulations in LRS can affect communication and decision-making processes. A qualitative study was conducted at 17 different sites in 12 developing countries in Asia, Latin America, and Africa. Data from observations of 68 in situ simulated pediatric emergencies were coded for thematic analysis. Sixty-two different "key informants" were interviewed regarding perceived benefit of simulations. Coding of observations and interviews yielded common themes: impact of culture on team hierarchy, impact of communication and language barriers on situational awareness, systematic emergency procedures, role delineation, shared cognition and resource awareness through simulation, logistic barriers to patient care, and use of recognition-primed decision-making by experienced clinicians. Changes in clinical environments were implemented as a result of simulations. Ad hoc teams in LRS face challenges in caring safely for patients; these include language and cultural barriers, as well as environmental and resource constraints. Engaging teams in simulations may promote improved communication, identification of systems issues and latent threats to target for remediation. There may be a role for training novices in use of recognition-primed or algorithmic decision-making strategies to improve rapidity and efficiency of decisions in LRS. Copyright © 2015 by the American Academy of Pediatrics.

  7. The accountability for reasonableness approach to guide priority setting in health systems within limited resources

    DEFF Research Database (Denmark)

    Byskov, Jens; Marchal, Bruno; Maluka, Stephen

    2014-01-01

    researchers was formed to implement, and continually assess and improve the application of the four conditions. Researchers evaluated the intervention using qualitative and quantitative data collection and analysis methods. RESULTS: The values underlying the AFR approach were in all three districts well...... to a broadened engagement of health team members and other stakeholders in priority setting and other decision-making processes. CONCLUSIONS: District stakeholders were able to take greater charge of closing the gap between nationally set planning on one hand and the local realities and demands of the served...... communities on the other within the limited resources at hand. This study thus indicates that the operationalization of the four broadly defined and linked conditions is both possible and seems to be responding to an actual demand. This provides arguments for the continued application and further assessment...

  8. Generalized Kuhn-Tucker Conditions for N-Firm Stochastic Irreversible Investment under Limited Resources

    CERN Document Server

    Chiarolla, Maria B; Riedel, Frank

    2012-01-01

    In this paper we study a continuous time, optimal stochastic investment problem under limited resources in a market with N firms. The investment processes are subject to a time-dependent stochastic constraint. Rather than using a dynamic programming approach, we exploit the concavity of the profit functional to derive some necessary and sufficient first order conditions for the corresponding Social Planner optimal policy. Our conditions are a stochastic infinite-dimensional generalization of the Kuhn-Tucker Theorem. As a subproduct we obtain an enlightening interpretation of the first order conditions for a single firm in Bank [5]. In the infinite-horizon case, with operating profit functions of Cobb-Douglas type, our method allows the explicit calculation of the optimal policy in terms of the base capacity process, i.e. the unique solution of the Bank and El Karoui representation problem [4].

  9. Supporting research sites in resource-limited settings: challenges in implementing information technology infrastructure.

    Science.gov (United States)

    Whalen, Christopher J; Donnell, Deborah; Tartakovsky, Michael

    2014-01-01

    As information and communication technology infrastructure becomes more reliable, new methods of electronic data capture, data marts/data warehouses, and mobile computing provide platforms for rapid coordination of international research projects and multisite studies. However, despite the increasing availability of Internet connectivity and communication systems in remote regions of the world, there are still significant obstacles. Sites with poor infrastructure face serious challenges participating in modern clinical and basic research, particularly that relying on electronic data capture and Internet communication technologies. This report discusses our experiences in supporting research in resource-limited settings. We describe examples of the practical and ethical/regulatory challenges raised by the use of these newer technologies for data collection in multisite clinical studies.

  10. Emerging technologies in point-of-care molecular diagnostics for resource-limited settings.

    Science.gov (United States)

    Peeling, Rosanna W; McNerney, Ruth

    2014-06-01

    Emerging molecular technologies to diagnose infectious diseases at the point at which care is delivered have the potential to save many lives in developing countries where access to laboratories is poor. Molecular tests are needed to improve the specificity of syndromic management, monitor progress towards disease elimination and screen for asymptomatic infections with the goal of interrupting disease transmission and preventing long-term sequelae. In simplifying laboratory-based molecular assays for use at point-of-care, there are inevitable compromises between cost, ease of use and test performance. Despite significant technological advances, many challenges remain for the development of molecular diagnostics for resource-limited settings. There needs to be more advocacy for these technologies to be applied to infectious diseases, increased efforts to lower the barriers to market entry through streamlined and harmonized regulatory approaches, faster policy development for adoption of new technologies and novel financing mechanisms to enable countries to scale up implementation.

  11. Commencing open heart surgery in resource limited countries: lessons from the LASUTH experience.

    Science.gov (United States)

    Oludara, Mobolaji Adewale; Nwiloh, Jonathan; Fabamwo, Adetokunbo; Adebola, Phillip

    2014-01-01

    The challenge of commencing cardiac surgery in developing countries of Africa is onerous. We present a model from the experience of carrying out open cardiac surgical procedures at the Lagos State University Teaching Hospital (LASUTH) with three separate missions between 2004 and 2006. This paper details the challenges of starting open heart surgery in a resource limited environment. We propose that owing to the huge financial investment needed, government sponsorship as well as collaboration with overseas based and local non-governmental agencies may be required to jump start the process of open cardiac surgery. Local staff training opportunities are also provided by such missions and this can further be complemented by overseas exposure in areas of need for capacity building. In our centre, the initial investment has led to the recruitment of additional trained staff including 2 cardiothoracic surgeons. Further benefits of training of 2 perfusionists and a nurse has improved capacity in cardiac surgery service at our center.

  12. Feasibility of HIV point-of-care tests for resource-limited settings: challenges and solutions.

    Science.gov (United States)

    Stevens, Wendy; Gous, Natasha; Ford, Nathan; Scott, Lesley E

    2014-09-08

    Improved access to anti-retroviral therapy increases the need for affordable monitoring using assays such as CD4 and/or viral load in resource-limited settings. Barriers to accessing treatment, high rates of loss to initiation and poor retention in care are prompting the need to find alternatives to conventional centralized laboratory testing in certain countries. Strong advocacy has led to a rapidly expanding repertoire of point-of-care tests for HIV. point-of-care testing is not without its challenges: poor regulatory control, lack of guidelines, absence of quality monitoring and lack of industry standards for connectivity, to name a few. The management of HIV increasingly requires a multidisciplinary testing approach involving hematology, chemistry, and tests associated with the management of non-communicable diseases, thus added expertise is needed. This is further complicated by additional human resource requirements and the need for continuous training, a sustainable supply chain, and reimbursement strategies. It is clear that to ensure appropriate national implementation either in a tiered laboratory model or a total decentralized model, clear country-specific assessments need to be conducted.

  13. Critical Minerals and Energy–Impacts and Limitations of Moving to Unconventional Resources

    Directory of Open Access Journals (Sweden)

    Benjamin C. McLellan

    2016-05-01

    Full Text Available The nexus of minerals and energy becomes ever more important as the economic growth and development of countries in the global South accelerates and the needs of new energy technologies expand, while at the same time various important minerals are declining in grade and available reserves from conventional mining. Unconventional resources in the form of deep ocean deposits and urban ores are being widely examined, although exploitation is still limited. This paper examines some of the implications of the transition towards cleaner energy futures in parallel with the shifts through conventional ore decline and the uptake of unconventional mineral resources. Three energy scenarios, each with three levels of uptake of renewable energy, are assessed for the potential of critical minerals to restrict growth under 12 alternative mineral supply patterns. Under steady material intensities per unit of capacity, the study indicates that selenium, indium and tellurium could be barriers in the expansion of thin-film photovoltaics, while neodymium and dysprosium may delay the propagation of wind power. For fuel cells, no restrictions are observed.

  14. Diagnosis of primary ciliary dyskinesia: potential options for resource-limited countries

    Directory of Open Access Journals (Sweden)

    Nisreen Rumman

    2017-01-01

    Full Text Available Primary ciliary dyskinesia is a genetic disease of ciliary function leading to chronic upper and lower respiratory tract symptoms. The diagnosis is frequently overlooked because the symptoms are nonspecific and the knowledge about the disease in the primary care setting is poor. Additionally, none of the available tests is accurate enough to be used in isolation. These tests are expensive, and need sophisticated equipment and expertise to analyse and interpret results; diagnosis is therefore only available at highly specialised centres. The diagnosis is particularly challenging in countries with limited resources due to the lack of such costly equipment and expertise. In this review, we discuss the importance of early and accurate diagnosis especially for countries where the disease is clinically prevalent but diagnostic tests are lacking. We review the diagnostic tests available in specialised centres (nasal nitric oxide, high-speed video microscopy, transmission electron microscopy, immunofluorescence and genetics. We then consider modifications that might be considered in less well-resourced countries whilst maintaining acceptable accuracy.

  15. Leapfrog diagnostics: Demonstration of a broad spectrum pathogen identification platform in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    Leski Tomasz A

    2012-07-01

    Full Text Available Abstract Background Resource-limited tropical countries are home to numerous infectious pathogens of both human and zoonotic origin. A capability for early detection to allow rapid outbreak containment and prevent spread to non-endemic regions is severely impaired by inadequate diagnostic laboratory capacity, the absence of a “cold chain” and the lack of highly trained personnel. Building up detection capacity in these countries by direct replication of the systems existing in developed countries is not a feasible approach and instead requires “leapfrogging” to the deployment of the newest diagnostic systems that do not have the infrastructure requirements of systems used in developed countries. Methods A laboratory for molecular diagnostics of infectious agents was established in Bo, Sierra Leone with a hybrid solar/diesel/battery system to ensure stable power supply and a satellite modem to enable efficient communication. An array of room temperature stabilization and refrigeration technologies for reliable transport and storage of reagents and biological samples were also tested to ensure sustainable laboratory supplies for diagnostic assays. Results The laboratory demonstrated its operational proficiency by conducting an investigation of a suspected avian influenza outbreak at a commercial poultry farm at Bo using broad range resequencing microarrays and real time RT-PCR. The results of the investigation excluded influenza viruses as a possible cause of the outbreak and indicated a link between the outbreak and the presence of Klebsiella pneumoniae. Conclusions This study demonstrated that by application of a carefully selected set of technologies and sufficient personnel training, it is feasible to deploy and effectively use a broad-range infectious pathogen detection technology in a severely resource-limited setting.

  16. Ethical considerations in HIV prevention and vaccine research in resource-limited settings.

    Science.gov (United States)

    Garner, Samual A; Anude, Chuka J; Adams, Elizabeth; Dawson, Liza

    2014-09-01

    HIV prevention research has been facing increasing ethical and operational challenges. Factors influencing the design and conduct of HIV prevention trials include a rapidly changing evidence base, new biomedical prevention methods and modalities being tested, a large diversity of countries, sites and populations affected by HIV and participating in trials, and challenges of developing and making available products that will be feasible and affordable for at-risk populations. To discuss these challenges, a meeting, Ethical considerations around novel combination prevention modalities in HIV prevention and vaccine trials in resource-limited settings, was convened by NIH/NIAID/Division of AIDS on April 22-23, 2013. Several themes emerged from the meeting: (1) because of both trial design and ethical complexities, choosing prevention packages and designing combination prevention research trials will need to be evaluated on a case by case basis in different clinical trials, countries, and health systems; (2) multilevel stakeholder engagement from the beginning is vital to a fair and transparent process and also to designing ethical and relevant trials; (3) research should generally be responsive to a host country's needs, and sponsors and stakeholders should work together to address potential barriers to future access; and finally, (4) another meeting including a broader group of stakeholders is needed to address many of the outstanding ethical issues raised by this meeting. We offer an overview of the meeting and the key discussion points and recommendations to help guide the design and conduct of future HIV prevention and vaccine research in resource-limited settings.

  17. Floral resource limitation severely reduces butterfly survival, condition and flight activity in simplified agricultural landscapes.

    Science.gov (United States)

    Lebeau, Julie; Wesselingh, Renate A; Van Dyck, Hans

    2016-02-01

    Agricultural intensification has a strong negative impact on farmland biodiversity (including flower-visiting insects), but understanding the mechanisms involved in this requires experimental work. We document the impact of nectar limitation on the performance of a flower-visiting insect, the meadow brown butterfly Maniola jurtina. We conducted two types of experiments: a field experiment in agricultural landscapes with grasslands of different management intensity and an experiment in outdoor flight cages in which the nectar supply was simulated. For the field experiment, we introduced an array of nectar resources in intensively managed, nectar-poor meadows and in extensively managed, flower-rich grasslands and counted flower visitors. Despite higher butterfly abundance in the extensive meadows, our introduced nectar sources were more frequently visited in intensive meadows, indicating the lack of floral resources. The 48-h confinement under nectar-poor conditions in the flight cages had a strong negative effect on body condition, flight activity and lifetime survival compared to butterflies under nectar-rich conditions. Female lifespan was reduced by 22% and male lifespan even by 43%. Agricultural landscapes that provide limited amounts of floral nectar, and no high-quality, preferred nectar sources relative to the needs of the flower-visiting species, may create ecological sinks. Regards an insect's performance, the simple presence of nectar is not necessarily functionally adequate. The effectiveness of agri-environmental schemes for flower-visiting insects (e.g. flower strips) could be improved based on ecological and evolutionary insights on the effects of specific nectar quantities and qualities.

  18. Feeding strategy of wild herbivores in habitats of limited food resources

    Directory of Open Access Journals (Sweden)

    Jiří Kamler

    2011-06-01

    Full Text Available In mountain environment of the Jeseníky Mts., we studied the botanical composition and quality of diets of red deer, roe deer and chamois as well as utilization of their food supply. The data were collected from two localities of different altitudes and food supply. The locality on summits was covered mostly with grasses in herb layer and inhabited by chamois and red deer, while in the lower locations raspberry, forbs and broadleaved tree was abundant and red and roe deer were presented. The aim of the study was to analyze a feeding strategy of three ungulate species in mountain habitats with limited food supply and to deduce implications to management of their populations. (1 Botanic composition of the ungulate food was influenced not only by their foraging specialisation but also food supply was very important. Red deer consumed grasses (more than 90 percent of volume on the summit in growing season while forbs and browse were presented in substantial amount in its diet in lower altitudes. (2 The food quality based on nitrogen content was higher in general in roe deer than in the others ungulates but during late winter the roe deer consumed the diet based on spruce needles of very low quality. The quality of red deer diet was lower in the summit area (grassy habitats than at foot hills where the food supply was more various. (3 The roe deer distribution can be restricted by absence of high quality food resources in ground vegetation while red deer and chamois can use food of lower quality (grasses. (5 Winter is a critical period for all study species when the food supply is a worst quality and the ungulate diets were similar and the possibility of competition for limited resources increase.

  19. Safety, efficacy, and pharmacokinetics of rilpivirine: systematic review with an emphasis on resource-limited settings

    Directory of Open Access Journals (Sweden)

    Ford N

    2011-04-01

    Full Text Available Nathan Ford1,2, Janice Lee1, Isabelle Andrieux-Meyer1, Alexandra Calmy1,31Médecins Sans Frontières, Geneva, Switzerland; 2Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa; 3Service of Infectious Diseases, Geneva University Hospital, Geneva, SwitzerlandAbstract: The vast majority of people living with human immunodeficiency virus (HIV/acquired immune deficiency syndrome reside in the developing world, in settings characterized by limited health budgets, critical shortages of doctors, limited laboratory monitoring, a substantial burden of HIV in children, and high rates of coinfection, in particular tuberculosis. Therefore, the extent to which new antiretrovirals will contribute to improvements in the management of HIV globally will depend to a large extent on their affordability, ease of use, low toxicity profile, availability as pediatric formulations, and compatibility with tuberculosis and other common drugs. We undertook a systematic review of the available evidence regarding drug interactions, and the efficacy and safety of rilpivirine (also known as TMC-278, and assessed our findings in view of the needs and constraints of resource-limited settings. The main pharmacokinetic interactions relevant to HIV management reported to date include reduced bioavailability of rilpivirine when coadministered with rifampicin, rifabutin or acid suppressing agents, and reduced bioavailability of ketoconazole. Potential recommendations for dose adjustment to compensate for these interactions have not been elaborated. Trials comparing rilpivirine and efavirenz found similar outcomes up to 96 weeks in intent-to-treat analysis; failure of rilpivirine was mainly virological, whereas failure among those exposed to efavirenz was mainly related to the occurrence of adverse events. Around half of the patients who fail rilpivirine develop non-nucleoside reverse transcriptase inhibitor resistance mutations

  20. When to start antiretroviral therapy in resource-limited settings: a human rights analysis

    Directory of Open Access Journals (Sweden)

    Calmy Alexandra

    2010-03-01

    Full Text Available Abstract Background Recent evidence from developed and developing countries shows clear clinical and public health benefit to starting antiretroviral therapy (ART earlier. While discussions about when to start ART have often focused on the clinical risks and benefits, the main issue is one of fair limit-setting. We applied a human rights framework to assess a policy of early treatment initiation according to the following criteria: public-health purpose; likely effectiveness; specificity; human rights burdens and benefits; potential for less restrictive approaches; and fair administration. Discussion According to our analysis, a policy of earlier ART initiation would better serve both public health and human rights objectives. We highlight a number of policy approaches that could be taken to help meet this aim, including increased international financial support, alternative models of care, and policies to secure the most affordable sources of appropriate antiretroviral drugs. Summary Widespread implementation of earlier ART initiation is challenging in resource-limited settings. Nevertheless, rationing of essential medicines is a restriction of human rights, and the principle of least restriction serves to focus attention on alternative measures such as adapting health service models to increase capacity, decreasing costs, and seeking additional international funding. Progressive realisation using well-defined steps will be necessary to allow for a phased implementation as part of a framework of short-term targets towards nationwide policy adoption, and will require international technical and financial support.

  1. Ranking CCR-efficient units based on the indicator with limited resources

    Directory of Open Access Journals (Sweden)

    Amir Reza Khaki

    2012-10-01

    Full Text Available Data Envelopment Analysis (DEA is one of the most popular techniques for measuring the relative efficiencies of a set of decision making units (DMUs, which use different inputs producing various outputs. Ranking of efficient DMUs is one of the most interesting DEA perspectives. However, there are cases where we see some limitations on available resources and the proposed model of this paper is associated with Indicator with Limited Sources (ILS, which affects ranking methods. The ILS exists as fixed amount in a community and the DMUs can own it with their abilities. When a DMU loses the same amount of the indicator, the rest of the DMUs are able to own some without even changing their capacities of other indicators and or vice versa. If a DMU looks for more of the same amount of the indicator, the rest of the DMUs have to supply it without even changing their capacity of other indicators. This paper develops a ranking method based on the ILS for the efficient DMUs, when there is changes either in inputs/ outputs ILS. The implementation of the proposed model is applied for a case study of banking system.

  2. SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

    Directory of Open Access Journals (Sweden)

    Sheri L Lewis

    Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

  3. Beyond CO2: Changes in Limiting Resources in California Oak Woodland

    Science.gov (United States)

    Hasselquist, N.; Allen, M.

    2007-12-01

    As atmospheric CO2 continues to increase, other resources become even more limiting to plants and the wildland ecosystems they support. Traditionally, California Mediterranean-type ecosystems are limited by water, then N. In these ecosystems, CO2 enrichment causes a minor increase in production associated with enhanced water-use efficiency, but N rapidly becomes the limiting factor to both production and to soil organism dynamics. In urbanizing areas, such as southern California, strong gradients in NOx deposition are also created by vehicular pollution. We have studied the regulation of N uptake by mycorrhizae in Coast Live Oak (Quercus agrifolia) using information with natural abundance from the early 1900s, current plants and fungi, and modeling change. Contrasts were made from a high NOx deposition site, a low deposition site, and a site where NOx deposition is rapidly increasing. We examined natural abundance δ15 N of current and past plant material (leaves, wood), mycorrhizal and saprobic fungal fruiting bodies, and soil. We modeled relative N uptake, fractionation, and transport between soil, fungus and plant. Our data show complex interactions between increasing NOx deposition and increasing atmospheric CO2 on mycorrhizal-plant interactions. There is a significant shift in N sources and reduction upon mycorrhizae with NOx deposition. However, the elevated CO2 appears to also have created a greater N demand on the trees, increasing dependence on mycorrhizae and the ability of the fungi to acquire organic N and NH4. The individual fungal species differ among sites, but complex trends between fungal genera and trees can be seen. Projections of increasing atmospheric CO2 and regional NOx deposition suggest strong but complex gradients in fungal-oak interactions with decreasing dependence on mycorrhizae near urbanizing areas, mediated by the rate of increasing CO2 and inorganic NOx deposition, and paradoxically, increasing dependency on mycorrhizae and organic

  4. Trends in Overall Mortality, and Timing and Cause of Death among Extremely Preterm Infants near the Limit of Viability

    Science.gov (United States)

    Sung, Sein; Ahn, So Yoon; Park, Won Soon

    2017-01-01

    Objective To investigate the trends in mortality, as well as in the timing and cause of death, among extremely preterm infants at the limit of viability, and thus to identify the clinical factors that contribute to decreased mortality. Methods We retrospectively reviewed the medical records of 382 infants born at 23–26 weeks’ gestation; 124 of the infants were born between 2001 and 2005 (period I) and 258 were born between 2006 and 2011 (period II). We stratified the infants into two subgroups–“23–24 weeks” and “25–26 weeks”–and retrospectively analyzed the clinical characteristics and mortality in each group, as well as the timing and cause of death. Univariate and multivariate logistic regression analyses were done to identify the clinical factors associated with mortality. Results The overall mortality rate in period II was 16.7% (43/258), which was significantly lower than that in period I (30.6%; 38/124). For overall cause of death, there were significantly fewer deaths due to sepsis (2.4% [6/258] vs. 8.1% [10/124], respectively) and air-leak syndrome (0.8% [2/258] vs. 4.8% (6/124), respectively) during period II than during period I. Among the clinical factors of time period, 1-and 5-min Apgar score, antenatal steroid identified significant by univariate analyses. 5-min Apgar score and antenatal steroid use were significantly associated with mortality in multivariate analyses. Conclusion Improved mortality rate attributable to fewer deaths due to sepsis and air leak syndrome in the infants with 23–26 weeks’ gestation was associated with higher 5-minute Apgar score and more antenatal steroid use. PMID:28114330

  5. New nucleic acid testing devices to diagnose infectious diseases in resource-limited settings.

    Science.gov (United States)

    Maffert, P; Reverchon, S; Nasser, W; Rozand, C; Abaibou, H

    2017-06-01

    Point-of-care diagnosis based on nucleic acid testing aims to incorporate all the analytical steps, from sample preparation to nucleic acid amplification and detection, in a single device. This device needs to provide a low-cost, robust, sensitive, specific, and easily readable analysis. Microfluidics has great potential for handling small volumes of fluids on a single platform. Microfluidic technology has recently been applied to paper, which is already used in low-cost lateral flow tests. Nucleic acid extraction from a biological specimen usually requires cell filtration and lysis on specific membranes, while affinity matrices, such as chitosan or polydiacetylene, are well suited to concentrating nucleic acids for subsequent amplification. Access to electricity is often difficult in resource-limited areas, so the amplification step needs to be equipment-free. Consequently, the reaction has to be isothermal to alleviate the need for a thermocycler. LAMP, NASBA, HDA, and RPA are examples of the technologies available. Nucleic acid detection techniques are currently based on fluorescence, colorimetry, or chemiluminescence. For point-of-care diagnostics, the results should be readable with the naked eye. Nowadays, interpretation and communication of results to health professionals could rely on a smartphone, used as a telemedicine device. The major challenge of creating an "all-in-one" diagnostic test involves the design of an optimal solution and a sequence for each analytical step, as well as combining the execution of all these steps on a single device. This review provides an overview of available materials and technologies which seem to be adapted to point-of-care nucleic acid-based diagnosis, in low-resource areas.

  6. Satellite SAR applied in offhore wind resource mapping: possibilities and limitations

    Science.gov (United States)

    Hasager, C. B.

    Satellite remote sensing of ocean wind fields from Synthetic Aperture Radar (SAR) observations is presented. The study is based on a series of more than 60 ERS-2 SAR satellite scenes from the Horns Rev in the North Sea. The wind climate from the coastline and 80 km offshore is mapped in detail with a resolution of 400 m by 400 m grid cells. Spatial variations in wind speed as a function of wind direction and fetch are observed and discussed. The satellite wind fields are compared to in-situ observations from a tall offshore meteorological mast at which wind speed at 4 levels are analysed. The mast is located 14 km offshore and the wind climate is observed continously since May 1999. For offshore wind resource mapping the SAR-based wind field maps can constitute an alternative to in-situ observations and a practical method is developed for applied use in WAsP (Wind Atlas Analysis and Application Program). The software is the de facto world standard tool used for prediction of wind climate and power production from wind turbines and wind farms. The possibilities and limitations on achieving offshore wind resource estimates using SAR-based wind fields in lieu of in-situ data are discussed. It includes a presentation of the footprint area-averaging techniques tailored for SAR-based wind field maps. Averaging techniques are relevant for the reduction of noise apparent in SAR wind speed maps. Acknowledgments: Danish Research Agency (SAT-WIND Sagsnr. 2058-03-0006) for funding, ESA (EO-1356, AO-153) for ERS-2 SAR scenes, and Elsam Engineering A/S for in-situ met-data.

  7. Enhancing HIV Treatment Access and Outcomes Amongst HIV Infected Children and Adolescents in Resource Limited Settings.

    Science.gov (United States)

    Goga, Ameena Ebrahim; Singh, Yagespari; Singh, Michelle; Noveve, Nobuntu; Magasana, Vuyolwethu; Ramraj, Trisha; Abdullah, Fareed; Coovadia, Ashraf H; Bhardwaj, Sanjana; Sherman, Gayle G

    2017-01-01

    Introduction Increasing access to HIV-related care and treatment for children aged 0-18 years in resource-limited settings is an urgent global priority. In 2011-2012 the percentage increase in children accessing antiretroviral therapy was approximately half that of adults (11 vs. 21 %). We propose a model for increasing access to, and retention in, paediatric HIV care and treatment in resource-limited settings. Methods Following a rapid appraisal of recent literature seven main challenges in paediatric HIV-related care and treatment were identified: (1) lack of regular, integrated, ongoing HIV-related diagnosis; (2) weak facility-based systems for tracking and retention in care; (3) interrupted availability of dried blood spot cards (expiration/stock outs); (4) poor quality control of rapid HIV testing; (5) supply-related gaps at health facility-laboratory interface; (6) poor uptake of HIV testing, possibly relating to a fatalistic belief about HIV infection; (7) community-associated reasons e.g. non-disclosure and weak systems for social support, resulting in poor retention in care. Results To increase sustained access to paediatric HIV-related care and treatment, regular updating of Policies, review of inter-sectoral Plans (at facility and community levels) and evaluation of Programme implementation and impact (at national, subnational, facility and community levels) are non-negotiable critical elements. Additionally we recommend the intensified implementation of seven main interventions: (1) update or refresher messaging for health care staff and simple messaging for key staff at early childhood development centres and schools; (2) contact tracing, disclosure and retention monitoring; (3) paying particular attention to infant dried blood spot (DBS) stock control; (4) regular quality assurance of rapid HIV testing procedures; (5) workshops/meetings/dialogues between health facilities and laboratories to resolve transport-related gaps and to facilitate return of

  8. Extreme Drought Event and Shrub Invasion Reduce Oak Trees Functioning and Resilience on Water-Limited Ecosystems

    Science.gov (United States)

    Caldeira, M. C.; Lobo-do-Vale, R.; Lecomte, X.; David, T. S.; Pinto, J. G.; Bugalho, M. N.; Werner, C.

    2016-12-01

    Extreme droughts and plant invasions are major drivers of global change that can critically affect ecosystem functioning. Shrub encroachment is increasing in many regions worldwide and extreme events are projected to increase in frequency and intensity, namely in the Mediterranean region. Nevertheless, little is known about how these drivers may interact and affect ecosystem functioning and resilience Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event in a Mediterranean oak woodland, we show that the combination of native shrub invasion and extreme drought reduced ecosystem transpiration and the resilience of the key-stone oak tree species. We established six 25 x 25 m paired plots in a shrub (Cistus ladanifer L.) encroached Mediterranean cork-oak (Quercus suber L.) woodland. We measured sapflow and pre-dawn leaf water potential of trees and shrubs and soil water content in all plots during four years. We determined the resilience of tree transpiration to evaluate to what extent trees recovered from the extreme drought event. From February to November 2011 we conducted baseline measurements for plot comparison. In November 2011 all the shrubs from one of all the paired plots were cut and removed. Ecosystem transpiration was dominated by the water use of the invasive shrub, which further increased after the extreme drought. Simultaneously, tree transpiration in invaded plots declined more sharply (67 ± 13 %) than in plots cleared from shrubs (31 ± 11%) relative to the pre-drought year (2011). Trees in invaded plots were not able to recover in the following wetter year showing lower resilience to the extreme drought event. Our results imply that in Mediterranean-type of climates invasion by water spending species coupled with the projected recurrent extreme droughts will cause critical drought tolerance thresholds of trees to be overcome, thus increasing the probability of tree mortality.

  9. Clinical care for severe influenza and other severe illness in resource-limited settings: the need for evidence and guidelines.

    Science.gov (United States)

    Ortiz, Justin R; Jacob, Shevin T; West, T Eoin

    2013-09-01

    The 2009 influenza A (H1N1) pandemic highlighted the importance of quality hospital care of the severely ill, yet there is evidence that the impact of the 2009 pandemic was highest in low- and middle-income countries with fewer resources. Recent data indicate that death and suffering from seasonal influenza and severe illness in general are increased in resource-limited settings. However, there are limited clinical data and guidelines for the management of influenza and other severe illness in these settings. Life-saving supportive care through syndromic case management is used successfully in high-resource intensive care units and in global programs such as the Integrated Management of Childhood Illness (IMCI). While there are a variety of challenges to the management of the severely ill in resource-limited settings, several new international initiatives have begun to develop syndromic management strategies for these environments, including the World Health Organization's Integrated Management of Adult and Adolescent Illness Program. These standardized clinical guidelines emphasize syndromic case management and do not require high-resource intensive care units. These efforts must be enhanced by quality clinical research to provide missing evidence and to refine recommendations, which must be carefully integrated into existing healthcare systems. Realizing a sustainable, global impact on death and suffering due to severe influenza and other severe illness necessitates an ongoing and concerted international effort to iteratively generate, implement, and evaluate best-practice management guidelines for use in resource-limited settings.

  10. A LITHOTROPHIC CLOSTRIDIUM STRAIN WITH EXTREMELY THERMORESISTANT SPORES ISOLATED FROM A PECTIN-LIMITED CONTINUOUS CULTURE OF CLOSTRIDIUM-THERMOSACCHAROLYTICUM STRAIN HAREN

    NARCIS (Netherlands)

    VANRIJSSEL, M; VANDERVEEN, [No Value; HANSEN, TA

    1992-01-01

    A thermophilic Clostridium sp. with extremely thermoresistant spores was isolated from a pectin-limited continuous culture of Clostridium thermosaccharolyticum. The decimal reduction time of the spores was 70 min at 121-degrees-C. Because of the ability of the bacterium to grow both heterotrophicall

  11. Longitudinal decline of lower extremity muscle power in healthy and mobility-limited older adults: influence of muscle mass, strength, composition, neuromuscular activation and single fiber contractile properties

    Science.gov (United States)

    This longitudinal study examined the major physiological mechanisms that determine the age related loss of lower extremity muscle power in two distinct groups of older humans. We hypothesized that after ~3 years of follow-up, mobility-limited older adults (mean age: 77.2 +/- 4, n = 22, 12 females) w...

  12. Improvement of a questionnaire measuring activity limitations in rising and sitting down in patients with lower-extremity disorders living at home

    NARCIS (Netherlands)

    Roorda, LD; Molenaar, IW; Lankhorst, GJ; Bouter, LM

    2005-01-01

    Objective: To improve a self-administered questionnaire that includes 42 dichotomous items and measures activity limitations in rising and sitting down (R&S) in patients with lower-extremity disorders who live at home. Design: Cross-sectional study. Setting: Outpatient clinics of secondary and

  13. Measuring activity limitations in walking : Development of a hierarchical scale for patients with lower-extremity disorders who live at home

    NARCIS (Netherlands)

    Roorda, LD; Roebroeck, ME; van Tilburg, T; Molenaar, IW; Lankhorst, GJ; Bouter, LM

    2005-01-01

    Objective: To develop a hierarchical scale that measures activity limitations in walking in patients with lower-extremity disorders who live at home. Design: Cross-sectional study. Setting: Orthopedic workshops and outpatient clinics of secondary and tertiary care centers. Participants: Patients (N=

  14. Mobile learning for HIV/AIDS healthcare worker training in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Zolfo Maria

    2010-09-01

    Full Text Available Abstract Background We present an innovative approach to healthcare worker (HCW training using mobile phones as a personal learning environment. Twenty physicians used individual Smartphones (Nokia N95 and iPhone, each equipped with a portable solar charger. Doctors worked in urban and peri-urban HIV/AIDS clinics in Peru, where almost 70% of the nation's HIV patients in need are on treatment. A set of 3D learning scenarios simulating interactive clinical cases was developed and adapted to the Smartphones for a continuing medical education program lasting 3 months. A mobile educational platform supporting learning events tracked participant learning progress. A discussion forum accessible via mobile connected participants to a group of HIV specialists available for back-up of the medical information. Learning outcomes were verified through mobile quizzes using multiple choice questions at the end of each module. Methods In December 2009, a mid-term evaluation was conducted, targeting both technical feasibility and user satisfaction. It also highlighted user perception of the program and the technical challenges encountered using mobile devices for lifelong learning. Results With a response rate of 90% (18/20 questionnaires returned, the overall satisfaction of using mobile tools was generally greater for the iPhone. Access to Skype and Facebook, screen/keyboard size, and image quality were cited as more troublesome for the Nokia N95 compared to the iPhone. Conclusions Training, supervision and clinical mentoring of health workers are the cornerstone of the scaling up process of HIV/AIDS care in resource-limited settings (RLSs. Educational modules on mobile phones can give flexibility to HCWs for accessing learning content anywhere. However lack of softwares interoperability and the high investment cost for the Smartphones' purchase could represent a limitation to the wide spread use of such kind mLearning programs in RLSs.

  15. Mobile learning for HIV/AIDS healthcare worker training in resource-limited settings.

    Science.gov (United States)

    Zolfo, Maria; Iglesias, David; Kiyan, Carlos; Echevarria, Juan; Fucay, Luis; Llacsahuanga, Ellar; de Waard, Inge; Suàrez, Victor; Llaque, Walter Castillo; Lynen, Lutgarde

    2010-09-08

    We present an innovative approach to healthcare worker (HCW) training using mobile phones as a personal learning environment.Twenty physicians used individual Smartphones (Nokia N95 and iPhone), each equipped with a portable solar charger. Doctors worked in urban and peri-urban HIV/AIDS clinics in Peru, where almost 70% of the nation's HIV patients in need are on treatment. A set of 3D learning scenarios simulating interactive clinical cases was developed and adapted to the Smartphones for a continuing medical education program lasting 3 months. A mobile educational platform supporting learning events tracked participant learning progress. A discussion forum accessible via mobile connected participants to a group of HIV specialists available for back-up of the medical information. Learning outcomes were verified through mobile quizzes using multiple choice questions at the end of each module. In December 2009, a mid-term evaluation was conducted, targeting both technical feasibility and user satisfaction. It also highlighted user perception of the program and the technical challenges encountered using mobile devices for lifelong learning. With a response rate of 90% (18/20 questionnaires returned), the overall satisfaction of using mobile tools was generally greater for the iPhone. Access to Skype and Facebook, screen/keyboard size, and image quality were cited as more troublesome for the Nokia N95 compared to the iPhone. Training, supervision and clinical mentoring of health workers are the cornerstone of the scaling up process of HIV/AIDS care in resource-limited settings (RLSs). Educational modules on mobile phones can give flexibility to HCWs for accessing learning content anywhere. However lack of softwares interoperability and the high investment cost for the Smartphones' purchase could represent a limitation to the wide spread use of such kind mLearning programs in RLSs.

  16. Limiter

    Science.gov (United States)

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  17. How to introduce diagnostic ultrasound in medical institutions of limited resources.

    Science.gov (United States)

    Chaves, O E

    1983-01-01

    It is now generally accepted that diagnostic ultrasound may have a role in Medicine, independently of the technological level of a society, as well as of the geographical factors of influence on its pathology. This means that many countries require ultrasound equipment of low cost and a decision must be made as to what kind of ultrasound facilities to set up and how: a central ultrasound unit for general application or different specialized services in several hospital departments. Alternatively, it is suggested a combined action of the World Federation for Ultrasound in Medicine and Biology, the ultrasound departments of highly developed countries, dealers and medical institutions of limited resources for the setting up of an ultrasound unit. This should be preceded by previous scientific training of medical staff of those institutions on the main diagnostic ultrasound applications, a survey of the potential users, a selection of the staff for the new service and continuous information. An outline of a proposal for that program is presented.

  18. Refractive ocular conditions and reasons for spectacles renewal in a resource-limited economy

    Directory of Open Access Journals (Sweden)

    Folorunso Francisca N

    2010-05-01

    Full Text Available Abstract Background Although a leading cause of visual impairment and a treatable cause of blindness globally, the pattern of refractive errors in many populations is unknown. This study determined the pattern of refractive ocular conditions, reasons for spectacles renewal and the effect of correction on refractive errors in a resource-limited community. Methods A retrospective review of case records of 1,413 consecutive patients seen in a private optometry practice, Nigeria between January 2006 and July 2007. Results A total number of 1,216 (86.1% patients comprising of (486, 40% males and (730, 60% females with a mean age of 41.02 years SD 14.19 were analyzed. The age distribution peaked at peri-adolescent and the middle age years. The main ocular complaints were spectacles loss and discomfort (412, 33.9%, blurred near vision (399, 32.8% and asthenopia (255, 20.9%. The mean duration of ocular symptoms before consultation was 2.05 years SD 1.92. The most common refractive errors include presbyopia (431, 35.3%, hyperopic astigmatism (240, 19.7% and presbyopia with hyperopia (276, 22.7%. Only (59, 4.9% had myopia. Following correction, there were reductions in magnitudes of the blind (VA Conclusions Adequate correction of refractive errors reduces visual impairment and avoidable blindness and to achieve optimal control of refractive errors in the community, services should be targeted at individuals in the peri-adolescent and the middle age years.

  19. How the initial level of visibility and limited resource affect the evolution of cooperation

    Science.gov (United States)

    Han, Dun; Li, Dandan; Sun, Mei

    2016-06-01

    This work sheds important light on how the initial level of visibility and limited resource might affect the evolution of the players’ strategies under different network structure. We perform the prisoner’s dilemma game in the lattice network and the scale-free network, the simulation results indicate that the average density of death in lattice network decreases with the increases of the initial proportion of visibility. However, the contrary phenomenon is observed in the scale-free network. Further results reflect that the individuals’ payoff in lattice network is significantly larger than the one in the scale-free network. In the lattice network, the visibility individuals could earn much more than the invisibility one. However, the difference is not apparent in the scale-free network. We also find that a high Successful-Defection-Payoff (SDB) and a rich natural environment have relatively larger deleterious cooperation effects. A high SDB is beneficial to raising the level of visibility in the heterogeneous network, however, that has adverse visibility consequences in homogeneous network. Our result reveals that players are more likely to cooperate voluntarily under homogeneous network structure.

  20. Territorial resources, limits and strategies of local development processes and agri-food productions of quality

    Directory of Open Access Journals (Sweden)

    Severino Romano

    2011-02-01

    Full Text Available The aim of this work is to analyse the role that typical products can play in the local development process. Territorial resources involved, limits and strategies for their enhancement are analysed; this analysis will permit both to define the results that have been achieved since nowadays in the local development process and to point out future themes for the research in the field of agricultural economics. The typicality of an agri-food product regards qualitative characteristics that derive from its tie with the territory, this tie becomes a relevant element for the differentiation of the typical product from the others. In this context, the typical product maintains all the specificities associated to its origin, involving also aspects related to the traditions and the culture of the territories, to the collective dimension and to the local knowledge. Consumers tent to look for good which are differentiated and to connect authenticity and local specificity of food with healthiness. Due to the strong socio-economic ties that typical products have with the territory, they play a crucial role in the economy of the local systems and can promote development in lagging areas.

  1. Increasing demands on limited water resources: Consequences for two endangered plants in Amargosa Valley, USA.

    Science.gov (United States)

    Hasselquist, Niles J; Allen, Michael F

    2009-03-01

    Recent population expansion throughout the Southwest United States has created an unprecedented demand for already limited water resources, which may have severe consequences on the persistence of some species. Two such species are the federally protected Nitrophila mohavensis (Chenopodiaceae) and Grindelia fraxino-pratensis (Asteraceae) found in Amargosa Valley, one valley east of Death Valley, California. Because both species are federally protected, no plant material could be harvested for analysis. We therefore used a chamber system to collect transpired water for isotopic analysis. After a correction for isotopic enrichment during transpiration, δ(18)O values of plant xylem water were significantly different between N. mohavensis and G. fraxino-pratensis throughout the study. Using a multisource mixing model, we found that both N. mohavensis and G. fraxino-pratensis used soil moisture near the soil surface in early spring when surface water was present. However, during the dry summer months, G. fraxino-pratensis tracked soil moisture to deeper depths, whereas N. mohavensis continued to use soil moisture near the soil surface. These results indicate that pumping groundwater and subsequently lowering the water table may directly prevent G. fraxino-pratensis from accessing water, whereas these same conditions may indirectly affect N. mohavensis by reducing surface soil moisture and thus its ability to access water.

  2. Are nest sites actively chosen? Testing a common assumption for three non-resource limited birds

    Science.gov (United States)

    Goodenough, A. E.; Elliot, S. L.; Hart, A. G.

    2009-09-01

    Many widely-accepted ecological concepts are simplified assumptions about complex situations that remain largely untested. One example is the assumption that nest-building species choose nest sites actively when they are not resource limited. This assumption has seen little direct empirical testing: most studies on nest-site selection simply assume that sites are chosen actively (and seek explanations for such behaviour) without considering that sites may be selected randomly. We used 15 years of data from a nestbox scheme in the UK to test the assumption of active nest-site choice in three cavity-nesting bird species that differ in breeding and migratory strategy: blue tit ( Cyanistes caeruleus), great tit ( Parus major) and pied flycatcher ( Ficedula hypoleuca). Nest-site selection was non-random (implying active nest-site choice) for blue and great tits, but not for pied flycatchers. We also considered the relative importance of year-specific and site-specific factors in determining occupation of nest sites. Site-specific factors were more important than year-specific factors for the tit species, while the reverse was true for pied flycatchers. Our results show that nest-site selection, in birds at least, is not always the result of active choice, such that choice should not be assumed automatically in studies of nesting behaviour. We use this example to highlight the need to test key ecological assumptions empirically, and the importance of doing so across taxa rather than for single "model" species.

  3. Human Immunodeficiency Virus and Leprosy Coinfection: Challenges in Resource-Limited Setups

    Directory of Open Access Journals (Sweden)

    Charles M. Kwobah

    2012-01-01

    Full Text Available Mycobacteria leprae(leprosy and HIV coinfection are rare in Kenya. This is likely related to the low prevalence (1 per 10,000 of population of leprosy. Because leprosy is no longer a public health challenge there is generally a low index of suspicion amongst clinicians for its diagnosis. Management of a HIV-1-leprosy-coinfected individual in a resource-constrained setting is challenging. Some of these challenges include difficulties in establishing a diagnosis of leprosy; the high pill burden of cotreatment with both antileprosy and antiretroviral drugs (ARVs; medications’ side effects; drug interactions; scarcity of drug choices for both diseases. This challenge is more profound when managing a patient who requires second-line antiretroviral therapy (ART. We present an adult male patient coinfected with HIV and leprosy, who failed first-line antiretroviral therapy (ART and required second-line treatment. Due to limited choices in antileprosy drugs available, the patient received monthly rifampicin and daily lopinavir-/ritonavir-based antileprosy and ART regimens, respectively. Six months into his cotreatment, he seemed to have adequate virological control. This case report highlights the challenges of managing such a patient.

  4. Turning off the spigot: reducing drug-resistant tuberculosis transmission in resource-limited settings.

    Science.gov (United States)

    Nardell, E; Dharmadhikari, A

    2010-10-01

    Ongoing transmission and re-infection, primarily in congregate settings, is a key factor fueling the global multidrug-resistant/extensively drug-resistant tuberculosis (MDR/XDR-TB) epidemic, especially in association with the human immunodeficiency virus. Even as efforts to broadly implement conventional TB transmission control measures begin, current strategies may be incompletely effective under the overcrowded conditions extant in high-burden, resource-limited settings. Longstanding evidence suggesting that TB patients on effective therapy rapidly become non-infectious and that unsuspected, untreated TB cases account for the most transmission makes a strong case for the implementation of rapid point-of-care diagnostics coupled with fully supervised effective treatment. Among the most important decisions affecting transmission, the choice of an MDR-TB treatment model that includes community-based treatment may offer important advantages over hospital or clinic-based care, not only in cost and effectiveness, but also in transmission control. In the community, too, rapid identification of infectious cases, especially drug-resistant cases, followed by effective, fully supervised treatment, is critical to stopping transmission. Among the conventional interventions available, we present a simple triage and separation strategy, point out that separation is intimately linked to the design and engineering of clinical space and call attention to the pros and cons of natural ventilation, simple mechanical ventilation systems, germicidal ultraviolet air disinfection, fit-tested respirators on health care workers and short-term use of masks on patients before treatment is initiated.

  5. An innovative system for 3D clinical photography in the resource-limited settings

    Science.gov (United States)

    2014-01-01

    Background Kaposi’s sarcoma (KS) is the most frequently occurring cancer in Mozambique among men and the second most frequently occurring cancer among women. Effective therapeutic treatments for KS are poorly understood in this area. There is an unmet need to develop a simple but accurate tool for improved monitoring and diagnosis in a resource-limited setting. Standardized clinical photographs have been considered to be an essential part of the evaluation. Methods When a therapeutic response is achieved, nodular KS often exhibits a reduction of the thickness without a change in the base area of the lesion. To evaluate the vertical space along with other characters of a KS lesion, we have created an innovative imaging system with a consumer light-field camera attached to a miniature “photography studio” adaptor. The image file can be further processed by computational methods for quantification. Results With this novel imaging system, each high-quality 3D image was consistently obtained with a single camera shot at bedside by minimally trained personnel. After computational processing, all-focused photos and measurable 3D parameters were obtained. More than 80 KS image sets were processed in a semi-automated fashion. Conclusions In this proof-of-concept study, the feasibility to use a simple, low-cost and user-friendly system has been established for future clinical study to monitor KS therapeutic response. This 3D imaging system can be also applied to obtain standardized clinical photographs for other diseases. PMID:24929434

  6. Penetrating Orbital-Cranial Injuries Management in a Limited Resource Hospital in Latin America

    Science.gov (United States)

    Estebanez, Glyn; Garavito, Diana; López, Laura; Ortiz, Juan Carlos; Rubiano, Andrés M.

    2015-01-01

    Penetrating orbital-cranial injuries (POCIs) are difficult cases especially in hospitals in low-middle-income countries (LMIC) where resources are limited. We present a case series of POCI managed in a university hospital in such scenario. A retrospective case series was conducted including patients with POCI in 2011. Mechanism of injury, Glasgow Coma Scale score, imaging, medical and surgical management, complications, and Glasgow Outcome Scale (GOS) score were analyzed. A total of 30 patients with penetrating orbital injuries were admitted from March 2011 to December 2011. Of this group, only four patients were diagnosed with cranial penetration. Computed tomography (CT) angiography revealed orbital fractures and injury to frontal, temporal, or occipital lobes. Urgent craniotomy with isolation of ipsilateral carotid artery was performed. GOS score at discharge was 5 in three patients and 4 in one patient. POCIs are not uncommon in hospitals of LMIC. In such scenarios, a standard approach with CT angiography and early neurosurgical intervention results in good outcome. PMID:26576244

  7. Delivering pediatric HIV care in resource-limited settings: cost considerations in an expanded response.

    Science.gov (United States)

    Tolle, Michael A; Phelps, B Ryan; Desmond, Chris; Sugandhi, Nandita; Omeogu, Chinyere; Jamieson, David; Ahmed, Saeed; Reuben, Elan; Muhe, Lulu; Kellerman, Scott E

    2013-11-01

    If children are to be protected from HIV, the expansion of PMTCT programs must be complemented by increased provision of paediatric treatment. This is expensive, yet there are humanitarian, equity and children's rights arguments to justify the prioritization of treating HIV-infected children. In the context of limited budgets, inefficiencies cost lives, either through lower coverage or less effective services. With the goal of informing the design and expansion of efficient paediatric treatment programs able to utilize to greatest effect the available resources allocated to the treatment of HIV-infected children, this article reviews what is known about cost drivers in paediatric HIV interventions, and makes suggestions for improving efficiency in paediatric HIV programming. High-impact interventions known to deliver disproportional returns on investment are highlighted and targeted for immediate scale-up. Progress will carry a cost - increased funding, as well as additional data on intervention costs and outcomes, will be required if universal access of HIV-infected children to treatment is to be achieved and sustained.

  8. Intuitive ultrasonography for autonomous medical care in limited-resource environments

    Science.gov (United States)

    Dulchavsky, Scott A.; Sargsyan, Ashot E.; Garcia, Kathleen M.; Melton, Shannon L.; Ebert, Douglas; Hamilton, Douglas R.

    2011-05-01

    Management of health problems in limited resource environments, including spaceflight, faces challenges in both available equipment and personnel. The medical support for spaceflight outside Low Earth Orbit is still being defined; ultrasound (US) imaging is a candidate since trials on the International Space Station (ISS) prove that this highly informative modality performs very well in spaceflight. Considering existing estimates, authors find that US could be useful in most potential medical problems, as a powerful factor to mitigate risks and protect mission. Using outcome-oriented approach, an intuitive and adaptive US image catalog is being developed that can couple with just-in-time training methods already in use, to allow non-expert crew to autonomously acquire and interpret US data for research or diagnosis. The first objective of this work is to summarize the experience in providing imaging expertise from a central location in real time, enabling data collection by a minimally trained operator onsite. In previous investigations, just-in-time training was combined with real-time expert guidance to allow non-physician astronauts to perform over 80 h of complex US examinations on ISS, including abdominal, cardiovascular, ocular, musculoskeletal, dental/sinus, and thoracic exams. The analysis of these events shows that non-physician crew-members, after minimal training, can perform complex, quality US examinations. These training and guidance methods were also adapted for terrestrial use in professional sporting venues, the Olympic Games, and for austere locations including Mt. Everest. The second objective is to introduce a new imaging support system under development that is based on a digital catalog of existing sample images, complete with image recognition and acquisition logic and technique, and interactive multimedia reference tools, to guide and support autonomous acquisition, and possibly interpretation, of images without real-time link with a human

  9. Awareness and knowledge of ocular cancers in a resource-limited economy

    Directory of Open Access Journals (Sweden)

    Abdulkabir A Ayanniyi

    2010-01-01

    Full Text Available Aims: To determine awareness and knowledge of ocular cancers in a resource-limited setting. Material and Methods: A descriptive cross-sectional survey (2009 of 1,887 Nigerians using interviewer-administered questionnaire. Results: Respondents were 55.6% males, and mean age was 30 years, SD 9.5. Most respondents (77.8% had at least secondary education. Fewer respondents were aware of eye cancers (57.1% compared to cancers in general (73.7% (P<.001. Despite the male preponderance there were no associations between gender and awareness of ocular cancers (P=0.07 and cancers in general (P=0.85. However, education was associated with awareness of ocular cancers (P<.001 and cancers in general (P<.001. Ocular cancers were thought to be caused by corrosives 33.2%, trauma 21.4%, witchcraft 18.6%, genetic transmission 15.7%, sunlight 8.0%, radiations 2.5% and infections 0.6% (n = 883. Of 280 respondents, 41.1% based their knowledge of patients having ocular cancers on sources other than hospital diagnosis. Of 148 respondents, 16.2% were related to ′patients′ they knew had ocular cancers. There were 202 respondents who indicated challenges to accessing orthodox medical eye care services by ocular cancer patients as high cost 55.5%, long waiting period 23.3%, long distance 15.4% and poor attitude of health workers 5.9%. Conclusion: Awareness of ocular cancers compared to other cancers is low. Misconceptions on the causes of ocular cancers exist. Public ocular cancers health education can enhance awareness. The need to address barriers to accessing eye care is underscored.

  10. Prioritising prevention strategies for patients in Antiretroviral Treatment Programmes in Resource-Limited Settings

    Science.gov (United States)

    SPAAR, A.; GRABER, C.; DABIS, F.; COUTSOUDIS, A; BACHMANN, L.; MCINTYRE, J.; SCHECHTER, M.; PROZESKY, H.W.; TUBOI, S.; DICKINSON, D.; KUMARASAMY, N.; PUJDADES-RODRIQUEZ, M.; SPRINZ, E.; SCHILTHUIS, H.J.; CAHN, P.; LOW, N.; EGGER, M.

    2010-01-01

    Expanded access to antiretroviral therapy (ART) offers opportunities to strengthen HIV prevention in resource-limited settings. We invited 27 ART programmes from urban settings in Africa, Asia and South America to participate in a survey, with the aim to examine what preventive services had been integrated in ART programmes. Twenty-two programmes participated; 8 (36%) from South Africa, 2 from Brazil, 2 from Zambia and 1 each from Argentina, India, Thailand, Botswana, Ivory Coast, Malawi, Morocco, Uganda and Zimbabwe. Twenty-one sites (96%) provided health education and social support, and 18 (82%) provided HIV testing and counselling. All sites encouraged disclosure of HIV infection to spouses and partners, but only 11 (50%) had a protocol for partner notification. Twenty-one sites (96%) supplied male condoms, 7 (32%) female condoms and 20 (91%) provided prophylactic ART for the prevention of mother-to-child transmission. Seven sites (33%) regularly screened for sexually transmitted infections (STI). Twelve sites (55%) were involved in activities aimed at women or adolescents, and 10 sites (46%) in activities aimed at serodiscordant couples. Stigma and discrimination, gender roles and funding constraints were perceived as the main obstacles to effective prevention in ART programmes. We conclude that preventive services in ART programmes in lower income countries focus on health education and the provision of social support and male condoms. Strategies that might be equally or more important in this setting, including partner notification, prompt diagnosis and treatment of STI, and reduction of stigma in the community, have not been implemented widely. PMID:20473792

  11. A flexible, small positron emission tomography prototype for resource-limited laboratories

    Science.gov (United States)

    Miranda-Menchaca, A.; Martínez-Dávalos, A.; Murrieta-Rodríguez, T.; Alva-Sánchez, H.; Rodríguez-Villafuerte, M.

    2015-05-01

    Modern small-animal PET scanners typically consist of a large number of detectors along with complex electronics to provide tomographic images for research in the preclinical sciences that use animal models. These systems can be expensive, especially for resource-limited educational and academic institutions in developing countries. In this work we show that a small-animal PET scanner can be built with a relatively reduced budget while, at the same time, achieving relatively high performance. The prototype consists of four detector modules each composed of LYSO pixelated crystal arrays (individual crystal elements of dimensions 1 × 1 × 10 mm3) coupled to position-sensitive photomultiplier tubes. Tomographic images are obtained by rotating the subject to complete enough projections for image reconstruction. Image quality was evaluated for different reconstruction algorithms including filtered back-projection and iterative reconstruction with maximum likelihood-expectation maximization and maximum a posteriori methods. The system matrix was computed both with geometric considerations and by Monte Carlo simulations. Prior to image reconstruction, Fourier data rebinning was used to increase the number of lines of response used. The system was evaluated for energy resolution at 511 keV (best 18.2%), system sensitivity (0.24%), spatial resolution (best 0.87 mm), scatter fraction (4.8%) and noise equivalent count-rate. The system can be scaled-up to include up to 8 detector modules, increasing detection efficiency, and its price may be reduced as newer solid state detectors become available replacing the traditional photomultiplier tubes. Prototypes like this may prove to be very valuable for educational, training, preclinical and other biological research purposes.

  12. Evaluation of trans burr hole ultrasonography usefulness in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    V de P. Djientcheu

    2013-01-01

    Full Text Available Purpose: Transcranial ultrasound (US imaging of intracranial structures is a reliable technique that requires an opening in the skull. In young children the fontanelle serves this purpose, but in adults a postoperative skull defect or some other acquired skull bone defect could be used as potential windows for transcranial US imaging. This study is an audit on the usefulness of the trans burr hole US intracranial imaging technique in a neurosurgical unit in Cameroon (sub-Saharan Africa. Materials and Methods: From January 2001 through December 2004, all files of patients consecutively operated in the neurosurgical unit of the Central Hospital of Yaounde, who underwent an US exploration in the postoperative period through the acquired bone defect or through a skull fracture were reviewed. Transcranial US results were validated by a complementary CT scan or postoperative findings. Results: Seventeen patients were included. Trans burr hole US was effective in diagnosing or in excluding postoperative complications. Hydrocephalus was diagnosed (two cases or excluded (five cases after posterior a fossa surgery (five cases or in case of suspicion of drain dysfunction (two cases. Abscess (one case or chronic subdural hematoma (two cases were detected or excluded after cranial surgery for tumours (three cases, aneurysm (one case, compound depressed skull fracture (one case, or intracranial hematoma (three cases. In one case of posttraumatic swelling of the scalp, the US technique revealed an acquired meningoencephalocele. In one case, residual subdural empyema was detected through trans burr hole US. Conclusion: Trans burr hole US technique may be considered in the diagnosis of postoperative complications (abscesses or hematoma in adults after intracranial surgery or ventriculoperitoneal drain dysfunction especially in resource-limited setting as it is both cheap and widely available.

  13. Resource limits and conversion efficiency with implications for climate change and California's energy supply

    Science.gov (United States)

    Croft, Gregory Donald

    below 36 of the 40 carbon emission scenarios from the IPCC, and the global peak of coal production from existing coalfields is predicted to occur about the year 2011. The peak coal production rate calculated here is 160 EJ/y, and the associated peak carbon emissions from coal burning are 4.5 Gt C per year. After 2011, the production rates of coal and CO2 decline, reaching 1990 levels by the year 2037, and reaching 50% of the peak value in the year 2047. It is unlikely that future mines will reverse the trend predicted in the base case scenario here, and current efforts to sequester carbon or to convert coal into liquid fuels should be reexamined in light of resource limits. (Abstract shortened by UMI.)

  14. Advantages and Limitations of Usage of Open Educational Resources in Small Countries

    Science.gov (United States)

    Krelja Kurelovic, Elena

    2016-01-01

    Educational resources in the competitive world of higher education were often considered as key intellectual property, so access to those resources was restricted to privileged groups of students and professors, which is unacceptable in today's networked society. Today, an increasing number of institutions and individuals share such digital…

  15. Resource requirements for cancer registration in areas with limited resources: Analysis of cost data from four low- and middle-income countries.

    Science.gov (United States)

    Tangka, Florence K L; Subramanian, Sujha; Edwards, Patrick; Cole-Beebe, Maggie; Parkin, D Maxwell; Bray, Freddie; Joseph, Rachael; Mery, Les; Saraiya, Mona

    2016-12-01

    The key aims of this study were to identify sources of support for cancer registry activities, to quantify resource use and estimate costs to operate registries in low- and middle-income countries (LMIC) at different stages of development across three continents. Using the Centers for Disease Control and Prevention's (CDC's) International Registry Costing Tool (IntRegCosting Tool), cost and resource use data were collected from eight population-based cancer registries, including one in a low-income country (Uganda [Kampala)]), two in lower to middle-income countries (Kenya [Nairobi] and India [Mumbai]), and five in an upper to middle-income country (Colombia [Pasto, Barranquilla, Bucaramanga, Manizales and Cali cancer registries]). Host institution contributions accounted for 30%-70% of total investment in cancer registry activities. Cancer registration involves substantial fixed cost and labor. Labor accounts for more than 50% of all expenditures across all registries. The cost per cancer case registered in low-income and lower-middle-income countries ranged from US $3.77 to US $15.62 (United States dollars). In Colombia, an upper to middle-income country, the cost per case registered ranged from US $41.28 to US $113.39. Registries serving large populations (over 15 million inhabitants) had a lower cost per inhabitant (less than US $0.01 in Mumbai, India) than registries serving small populations (under 500,000 inhabitants) [US $0.22] in Pasto, Colombia. This study estimates the total cost and resources used for cancer registration across several countries in the limited-resource setting, and provides cancer registration stakeholders and registries with opportunities to identify cost savings and efficiency improvements. Our results suggest that cancer registration involve substantial fixed costs and labor, and that partnership with other institutions is critical for the operation and sustainability of cancer registries in limited resource settings. Although we

  16. Global observed long-term changes in temperature and precipitation extremes: A review of progress and limitations in IPCC assessments and beyond

    Directory of Open Access Journals (Sweden)

    Lisa V. Alexander

    2016-03-01

    Full Text Available The Intergovernmental Panel on Climate Change (IPCC first attempted a global assessment of long-term changes in temperature and precipitation extremes in its Third Assessment Report in 2001. While data quality and coverage were limited, the report still concluded that heavy precipitation events had increased and that there had been, very likely, a reduction in the frequency of extreme low temperatures and increases in the frequency of extreme high temperatures. That overall assessment had changed little by the time of the IPCC Special Report on Extremes (SREX in 2012 and the IPCC Fifth Assessment Report (AR5 in 2013, but firmer statements could be added and more regional detail was possible. Despite some substantial progress throughout the IPCC Assessments in terms of temperature and precipitation extremes analyses, there remain major gaps particularly regarding data quality and availability, our ability to monitor these events consistently and our ability to apply the complex statistical methods required. Therefore this article focuses on the substantial progress that has taken place in the last decade, in addition to reviewing the new progress since IPCC AR5 while also addressing the challenges that still lie ahead.

  17. Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system

    Science.gov (United States)

    Johnson, Christine K.; Tinker, M. Tim; Estes, James A.; Conrad, Patricia A.; Staedler, Michelle M.; Miller, Melissa A.; Jessup, David A.; Mazet, Jonna A.K.

    2014-01-01

    The processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. By combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (Enhydra lutris nereis) population growth: disease and resource limitation. This threatened population has struggled to recover despite protection, so we followed radio-tagged sea otters and evaluated infection with 2 disease-causing protozoal pathogens, Toxoplasma gondii and Sarcocystis neurona, to reveal risks that increased the likelihood of pathogen exposure. We identified patterns of pathogen infection that are linked to individual animal behavior, prey choice, and habitat use. We detected a high-risk spatial cluster of S. neurona infections in otters with home ranges in southern Monterey Bay and a coastal segment near San Simeon and Cambria where otters had high levels of infection with T. gondii. We found that otters feeding on abalone, which is the preferred prey in a resource-abundant marine ecosystem, had a very low risk of infection with either pathogen, whereas otters consuming small marine snails were more likely to be infected with T. gondii. Individual dietary specialization in sea otters is an adaptive mechanism for coping with limited food resources along central coastal California. High levels of infection with protozoal pathogens may be an adverse consequence of dietary specialization in this threatened species, with both depleted resources and disease working synergistically to limit recovery.

  18. Implementation of a competency-based residency curriculum : experiences from a resource-limited environment in the Caribbean

    NARCIS (Netherlands)

    Busari, Jamiu O.; Verhagen, Eduard A. A.; Muskiet, Fred D.; Duits, Ashley J.

    2008-01-01

    Background: The introduction of competency-based curricula in institutions situated in resource-limited environments is likely to pose new challenges for the implementation process. The St. Elisabeth Hospital (SEHOS) in Curacao, Dutch Caribbean, is affiliated to university teaching hospitals in the

  19. Qualitative Contrast between Knowledge-Limited Mixed-State and Variable-Resources Models of Visual Change Detection

    Science.gov (United States)

    Nosofsky, Robert M.; Donkin, Chris

    2016-01-01

    We report an experiment designed to provide a qualitative contrast between knowledge-limited versions of mixed-state and variable-resources (VR) models of visual change detection. The key data pattern is that observers often respond "same" on big-change trials, while simultaneously being able to discriminate between same and small-change…

  20. Implementation of a competency-based residency curriculum : experiences from a resource-limited environment in the Caribbean

    NARCIS (Netherlands)

    Busari, Jamiu O.; Verhagen, Eduard A. A.; Muskiet, Fred D.; Duits, Ashley J.

    2008-01-01

    Background: The introduction of competency-based curricula in institutions situated in resource-limited environments is likely to pose new challenges for the implementation process. The St. Elisabeth Hospital (SEHOS) in Curacao, Dutch Caribbean, is affiliated to university teaching hospitals in the

  1. The Effectiveness of Distance Education, Using Blended Method of Delivery for Limited-Resource Audiences in the Nutrition Education Program

    Science.gov (United States)

    Campbell, Casey; Koszewski, Wanda M.; Behrends, Donnia

    2013-01-01

    The study reported here sought to determine if the use of distance education lessons for teaching limited resource participants in a nutrition education program (NEP) is as effective as face-to-face methodology. One hundred and six participants were in the experimental group. Data was gathered at entry and examined behavior change, nutrient intake…

  2. Developing open source, self-contained disease surveillance software applications for use in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Campbell Timothy C

    2012-09-01

    Full Text Available Abstract Background Emerging public health threats often originate in resource-limited countries. In recognition of this fact, the World Health Organization issued revised International Health Regulations in 2005, which call for significantly increased reporting and response capabilities for all signatory nations. Electronic biosurveillance systems can improve the timeliness of public health data collection, aid in the early detection of and response to disease outbreaks, and enhance situational awareness. Methods As components of its Suite for Automated Global bioSurveillance (SAGES program, The Johns Hopkins University Applied Physics Laboratory developed two open-source, electronic biosurveillance systems for use in resource-limited settings. OpenESSENCE provides web-based data entry, analysis, and reporting. ESSENCE Desktop Edition provides similar capabilities for settings without internet access. Both systems may be configured to collect data using locally available cell phone technologies. Results ESSENCE Desktop Edition has been deployed for two years in the Republic of the Philippines. Local health clinics have rapidly adopted the new technology to provide daily reporting, thus eliminating the two-to-three week data lag of the previous paper-based system. Conclusions OpenESSENCE and ESSENCE Desktop Edition are two open-source software products with the capability of significantly improving disease surveillance in a wide range of resource-limited settings. These products, and other emerging surveillance technologies, can assist resource-limited countries compliance with the revised International Health Regulations.

  3. Sensing extremely limited H₂ contents by Pd nanogap connected to an amorphous InGaZnO thin-film transistor.

    Science.gov (United States)

    Lee, Young Tack; Jung, Hwaebong; Nam, Seung Hee; Jeon, Pyo Jin; Kim, Jin Sung; Jang, Byungjin; Lee, Wooyoung; Im, Seongil

    2013-10-07

    A palladium (Pd) nanogap-based thin-film has been connected to an electrically stable amorphous InGaZnO thin-film transistor, to form a hydrogen sensor demonstrating a dramatic sensing capability. As a result of the Pd connection to the transistor source, our sensor circuit greatly enhances the hydrogen-induced signal and sensing speed in the sense of output voltage, clearly resolving a minimum hydrogen content of 0.05%. When the nanogap-based Pd thin-film was connected to the transistor gate, an extremely limited hydrogen content of even less than 0.05% was visibly detected through gate voltage shifts. Our results exhibit the most promising and practical ways to sense extremely limited hydrogen contents, originating from two methods: transistor-to-Pd nanogap resistor and transistor-to-Pd nanogap capacitor coupling.

  4. Diarrhoea in a large prospective cohort of European travellers to resource-limited destinations

    Directory of Open Access Journals (Sweden)

    Pitzurra Raffaela

    2010-08-01

    Full Text Available Abstract Background Incidence rates of travellers' diarrhoea (TD need to be updated and risk factors are insufficiently known. Methods Between July 2006 and January 2008 adult customers of our Centre for Travel Health travelling to a resource-limited country for the duration of 1 to 8 weeks were invited to participate in a prospective cohort study. They received one questionnaire pre-travel and a second one immediately post-travel. First two-week incidence rates were calculated for TD episodes and a risk assessment was made including demographic and travel-related variables, medical history and behavioural factors. Results Among the 3100 persons recruited, 2800 could be investigated, resulting in a participation rate of 89.2%. The first two-weeks incidence for classic TD was 26.2% (95%CI 24.5-27.8. The highest rates were found for Central Africa (29.6%, 95% CI 12.4-46.8, the Indian subcontinent (26.3%, 95%CI 2.3-30.2 and West Africa (21.5%, 95%CI 14.9-28.1. Median TD duration was 2 days (range 1-90. The majority treated TD with loperamide (57.6%, while a small proportion used probiotics (23.0% and antibiotics (6.8%. Multiple logistic regression analysis on any TD to determine risk factors showed that a resolved diarrhoeal episode experienced in the 4 months pre-travel (OR 2.03, 95%CI 1.59-2.54, antidepressive comedication (OR 2.11, 95%CI 1.17-3.80, allergic asthma (OR 1.67, 95%CI 1.10-2.54, and reporting TD-independent fever (OR 6.56, 95%CI 3.06-14.04 were the most prominent risk factors of TD. Conclusions TD remains a frequent travel disease, but there is a decreasing trend in the incidence rate. Patients with a history of allergic asthma, pre-travel diarrhoea, or of TD-independent fever were more likely to develop TD while abroad.

  5. Antibiotic use and emerging resistance—how can resource-limited countries turn the tide?

    OpenAIRE

    Bebell, LM; Muiru, AN

    2014-01-01

    Antibiotic resistance is a global crisis driven by appropriate and inappropriate antibiotic use to treat human illness and promote animal growth. The antimicrobial resistance epidemic continues to spread due to the triple threat of unfettered access, minimal product regulation and oversight of antibiotic prescription, and lack of clinical diagnostic tools to support antibiotic de-escalation in low-resource settings. In high-resource settings, evidence-based strategies have improved appropriat...

  6. Human resources for health strategies adopted by providers in resource-limited settings to sustain long-term delivery of ART: a mixed-methods study from Uganda.

    Science.gov (United States)

    Zakumumpa, Henry; Taiwo, Modupe Oladunni; Muganzi, Alex; Ssengooba, Freddie

    2016-10-19

    Human resources for health (HRH) constraints are a major barrier to the sustainability of antiretroviral therapy (ART) scale-up programs in Sub-Saharan Africa. Many prior approaches to HRH constraints have taken a top-down trend of generalized global strategies and policy guidelines. The objective of the study was to examine the human resources for health strategies adopted by front-line providers in Uganda to sustain ART delivery beyond the initial ART scale-up phase between 2004 and 2009. A two-phase mixed-methods approach was adopted. In the first phase, a survey of a nationally representative sample of health facilities (n = 195) across Uganda was conducted. The second phase involved in-depth interviews (n = 36) with ART clinic managers and staff of 6 of the 195 health facilities purposively selected from the first study phase. Quantitative data was analysed based on descriptive statistics, and qualitative data was analysed by coding and thematic analysis. The identified strategies were categorized into five themes: (1) providing monetary and non-monetary incentives to health workers on busy ART clinic days; (2) workload reduction through spacing ART clinic appointments; (3) adopting training workshops in ART management as a motivation strategy for health workers; (4) adopting non-physician-centred staffing models; and (5) devising ART program leadership styles that enhanced health worker commitment. Facility-level strategies for responding to HRH constraints are feasible and can contribute to efforts to increase country ownership of HIV programs in resource-limited settings. Consideration of the human resources for health strategies identified in the study by ART program planners and managers could enhance the long-term sustainment of ART programs by providers in resource-limited settings.

  7. Mangrove expansion and contraction at a poleward range limit: Climate extremes and land-ocean temperature gradients

    Science.gov (United States)

    Osland, Michael J.; Day, Richard H.; Hall, Courtney T.; Brumfield, Marisa D; Dugas, Jason; Jones, William R.

    2017-01-01

    Within the context of climate change, there is a pressing need to better understand the ecological implications of changes in the frequency and intensity of climate extremes. Along subtropical coasts, less frequent and warmer freeze events are expected to permit freeze-sensitive mangrove forests to expand poleward and displace freeze-tolerant salt marshes. Here, our aim was to better understand the drivers of poleward mangrove migration by quantifying spatiotemporal patterns in mangrove range expansion and contraction across land-ocean temperature gradients. Our work was conducted in a freeze-sensitive mangrove-marsh transition zone that spans a land-ocean temperature gradient in one of the world's most wetland-rich regions (Mississippi River Deltaic Plain; Louisiana, USA). We used historical air temperature data (1893-2014), alternative future climate scenarios, and coastal wetland coverage data (1978-2011) to investigate spatiotemporal fluctuations and climate-wetland linkages. Our analyses indicate that changes in mangrove coverage have been controlled primarily by extreme freeze events (i.e., air temperatures below a threshold zone of -6.3 to -7.6 °C). We expect that in the past 121 years, mangrove range expansion and contraction has occurred across land-ocean temperature gradients. Mangrove resistance, resilience, and dominance were all highest in areas closer to the ocean where temperature extremes were buffered by large expanses of water and saturated soil. Under climate change, these areas will likely serve as local hotspots for mangrove dispersal, growth, range expansion, and displacement of salt marsh. Collectively, our results show that the frequency and intensity of freeze events across land-ocean temperature gradients greatly influences spatiotemporal patterns of range expansion and contraction of freeze-sensitive mangroves. We expect that, along subtropical coasts, similar processes govern the distribution and abundance of other freeze

  8. Modelling Management Practices in Viticulture while Considering Resource Limitations: The Dhivine Model.

    Science.gov (United States)

    Martin-Clouaire, Roger; Rellier, Jean-Pierre; Paré, Nakié; Voltz, Marc; Biarnès, Anne

    2016-01-01

    Many farming-system studies have investigated the design and evaluation of crop-management practices with respect to economic performance and reduction in environmental impacts. In contrast, little research has been devoted to analysing these practices in terms of matching the recurrent context-dependent demand for resources (labour in particular) with those available on the farm. This paper presents Dhivine, a simulation model of operational management of grape production at the vineyard scale. Particular attention focuses on representing a flexible plan, which organises activities temporally, the resources available to the vineyard manager and the process of scheduling and executing the activities. The model relies on a generic production-system ontology used in several agricultural production domains. The types of investigations that the model supports are briefly illustrated. The enhanced realism of the production-management situations simulated makes it possible to examine and understand properties of resource-constrained work-organisation strategies and possibilities for improving them.

  9. Critical determinants of the epilepsy treatment gap: a cross-national analysis in resource-limited settings

    Science.gov (United States)

    Meyer, Ana-Claire L.; Dua, Tarun; Boscardin, John; Escarce, José J.; Saxena, Shekhar; Birbeck, Gretchen L.

    2013-01-01

    Purpose Epilepsy is one of the most common serious neurological disorders worldwide. Our objective was to determine which economic, healthcare, neurology and epilepsy specific resources were associated with untreated epilepsy in resource-constrained settings. Methods A systematic review of the literature identified community-based studies in resource-constrained settings that calculated the epilepsy treatment gap, the proportion with untreated epilepsy, from prevalent active epilepsy cases. Economic, healthcare, neurology and epilepsy specific resources were taken from existing datasets. Poisson regression models with jackknifed standard errors were used to create bivariate and multivariate models comparing the association between treatment status and economic and health resource indicators. Relative risks were reported. Key Findings Forty-seven studies of 8285 individuals from 24 countries met inclusion criteria. Bivariate analysis demonstrated that individuals residing in rural locations had significantly higher risks of untreated epilepsy [Relative Risk(RR)=1.63; 95% confidence interval(CI):1.26,2.11]. Significantly lower risks of untreated epilepsy were observed for higher physician density [RR=0.65, 95% CI:0.55,0.78], presence of a lay [RR=0.74, 95%CI:0.60,0.91] or professional association for epilepsy [RR=0.73, 95%CI:0.59,0.91], or post-graduate neurology training program [RR=0.67, 95%CI:0.55, 0.82]. In multivariate models, higher physician density maintained significant effects [RR=0.67; 95%CI:0.52,0.88]. Significance Even among resource-limited regions, people with epilepsy in countries with fewer economic, healthcare, neurology and epilepsy specific resources are more likely to have untreated epilepsy. Community-based epilepsy care programs have improved access to treatment but in order to decrease the epilepsy treatment gap, poverty and inequalities of healthcare, neurological and epilepsy resources must be dealt with at the local, national, and global

  10. Assessment of the Adoption of Agroforestry Technologies by Limited-Resource Farmers in North Carolina

    Science.gov (United States)

    Faulkner, Paula E.; Owooh, Bismark; Idassi, Joshua

    2014-01-01

    Agroforestry is a natural resource management system that integrates trees, forages, and livestock. The study reported here was conducted to determine farmers' knowledge about and willingness to adopt agroforestry technologies in North Carolina. The study reported participants were primarily older, male farmers, suggesting the need to attract more…

  11. Measuring activity limitations in climbing stairs: development of a hierarchical scale for patients with lower-extremity disorders living at home.

    Science.gov (United States)

    Roorda, Leo D; Roebroeck, Marij E; van Tilburg, Theo; Lankhorst, Gustaaf J; Bouter, Lex M

    2004-06-01

    To develop a hierarchical scale that measures activity limitations in climbing stairs in patients with lower-extremity disorders living at home. Cross-sectional study with Mokken scale analysis of 15 dichotomous items. Outpatient clinics of secondary and tertiary care centers. Patients (N=759; mean age +/- standard deviation, 59.8+/-15.0y; 48% men) living at home, with different lower-extremity disorders: stroke, poliomyelitis, osteoarthritis, amputation, complex regional pain syndrome type I, and diabetic foot problems. Not applicable. (1) Fit of the monotone homogeneity model, indicating whether items can be used for measuring patients; (2) fit of the double monotonicity model, indicating invariant (hierarchical) item ordering; (3) intratest reliability, indicating repeatability of the sum score; and (4) differential item functioning, addressing the validity of comparisons between subgroups of patients. There was (1) good fit of the monotone homogeneity model (coefficient H=.50) for all items for all patients, and for subgroups defined by age, gender, and diagnosis; (2) good fit of the double monotonicity model (coefficient H(T)=.58); (3) good intratest reliability (coefficient rho=.90); and (4) no differential item functioning with respect to age and gender, but differential item functioning for 4 items in amputees compared with nonamputees. A hierarchical scale, with excellent scaling characteristics, has been developed for measuring activity limitations in climbing stairs in patients with lower-extremity disorders who live at home. However, measurements should be interpreted with caution when comparisons are made between patients with and without amputation.

  12. LIMITING POSSIBILITIES OF RESOURCE EXCHANGE PROCESS IN COMPLEX OPEN MICROECONOMIC SYSTEM

    Directory of Open Access Journals (Sweden)

    Serghey A. Amelkin

    2004-06-01

    Full Text Available A problem on extreme performance of microeconomic system with several firms is considered. Each firm aspires to increase the profit. Flows of the good between the firms determine the structure of the system. So, sequential structure corresponds to intermediaries (dealers operating in the market, parallel structure corresponds to competition in the market. The system at issue is an open economic system because of presence of external flows from the sources described by a distribution of the value of the good. The problem is solved for the basic structures: maximal profit and corresponding prices are found for each firm.

  13. Recursos hídricos e cidadania no Brasil: limites, alternativas e desafios Water resources and citizenship in Brazil: limitations, alternatives and challenges

    Directory of Open Access Journals (Sweden)

    Carlos José Saldanha Machado

    2003-12-01

    Full Text Available O artigo discute a relação entre a gestão de recursos hídricos e o exercício da cidadania no Brasil. Inicialmente, apresenta um quadro descritivo da distribuição da água e dos problemas associados com o crescimento populacional; em seguida, faz uma descrição das características da gestão da água e das inovações introduzidas com a Lei das Águas nº 9.433/97; na terceira parte, formula e defende argumentos em prol de uma gestão pública integrada e colegiada com negociação sociotécnica das águas ; finalmente, apresenta e discute algumas dificuldades e limites para a implantação e consolidação de uma política de recursos hídricos descentralizada, participativa e sustentável, bem como alguns mecanismos para que aquelas dificuldades e limites venham a ser superados, ou ao menos minimizados.The article discusses the relationship between water resources management and the exercise of citizenship in Brazil. At first, it presents a descriptive framework on water distribution and problems concerned to population growth. On the second part, it describes water management features and innovations introduced by the Water Law (nº 94.333/97. On the third part, it argues in favor of an integrated and collective public management of waterand a sociotechnical negotiation. Finally, it discusses some difficulties and limitations to implement and consolidate a decentralized, participative and sustainable water resources policy, as well as mechanisms to overcome or minimize such difficulties and limitations.

  14. Oxygen and pulse oximetry in childhood pneumonia: a survey of healthcare providers in resource-limited settings.

    Science.gov (United States)

    Ginsburg, Amy Sarah; Van Cleve, William C; Thompson, Mary I W; English, Mike

    2012-10-01

    Globally, pneumonia is the leading cause of death in children provider perceptions and practices regarding their role in childhood pneumonia, we conducted a survey using a convenience sampling strategy targeting clinicians working in resource-limited countries. Most respondents were physicians from public district and provincial hospitals with access to oxygen and pulse oximetry; however, reported therapeutic use for childhood pneumonia was low. Common barriers included insufficient supply, competition for use, lack of policies, guidelines and training and perceived high cost. Despite the frequency of hypoxemia, the inaccuracy of clinical predictors, the poor outcome hypoxemia portends and the effectiveness of pulse oximetry and oxygen in childhood pneumonia, our data indicate that these tools may be underused in resource-limited settings.

  15. [Aviation and high-altitude medicine for anaesthetists. Part 4: human performance limitations and crew resource management].

    Science.gov (United States)

    Egerth, Martin; Pump, Stefan; Graf, Jürgen

    2013-06-01

    For pilots and doctors, as well as a variety of other professions the knowledge of human performance limitations is essential, especially in critical situations. Crew resource management was developed in the 1980s in the aviation industry in order to ensure systematic training and support in such instances. Just recently, the value is recognized not only in other high reliability organizations but also in medicine. © Georg Thieme Verlag Stuttgart · New York.

  16. Proposing evidence-based strategies to strengthen implementation of healthcare reform in resource-limited settings: a summative analysis

    Science.gov (United States)

    Manyazewal, Tsegahun; Oosthuizen, Martha J; Matlakala, Mokgadi C

    2016-01-01

    Objectives Many resource-limited countries have adopted and implemented healthcare reform to improve the quality of healthcare, but few have had much impact and strategies in support of these efforts remain limited. We aimed to explore and propose evidence-based strategies to strengthen implementation of healthcare reform in resource-limited settings. Design Descriptive and exploratory designs in two phases. Phase I involved assessing the effectiveness of the healthcare reform implemented in Ethiopia in the form of business process reengineering, with evidence compiled from healthcare professionals through a self-administered questionnaire; and phase II involved proposing strategies and seeking consensus from experts using Delphi method. Setting Public hospitals in central Ethiopia. Participants 406 healthcare professionals and 10 senior health policy experts. Findings The healthcare reform that we evaluated was able to restructure hospital departments into case teams, with the goal of adopting a ‘one-stop shopping’ approach. However, shortages of critical infrastructure, furniture and supplies and job dissatisfaction continued to hamper the system. The most important predictors that influenced implementation of the reform were financial resources, top management commitment and support, collaborative working environment and information technology (IT). Five strategies with 14 operational objectives and 67 potential interventions that could strengthen the reform are proposed based on their strategic priority, which are as follows: reinforce patient-centred quality of care services; foster a healthy and respectful workforce environment; efficient and accountable leadership and governance; efficient use of hospital financing and maximise innovations and the use of health technologies. Conclusions Effective implementation of healthcare reform remained a challenge for governments in resource-limited settings. Resilient operational, clinical and governance functions

  17. Shenzhen Comprehensive Transport System Planning:An Exploration of Sustainable Urban Transport Development on Condition of Limited Resources

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With "integration" as the direction,Shenzhen Comprehensive Transport Planning integrates the plan,construction and management of all kinds of transport mode in the transport system,and integrates the transport with the social,economic and environment development.The planning specifies the strategic targets,key indicators,development strategies as well as major policies of the comprehensive transport system,which explores an alternative way for the sustainable urban transport development under the condition of limited resources in Shenzhen.

  18. Long Standing Esophageal Perforation due to Foreign Body Impaction in Children: A Therapeutic Challenge in a Resource Limited Setting

    Directory of Open Access Journals (Sweden)

    Ngo Nonga Bernadette

    2017-01-01

    Full Text Available Late presentation of foreign body impaction in the esophagus, complicated by perforation in children, has rarely been reported in the literature. Esophageal surgery is very difficult and challenging in Cameroon (a resource limited setting. We are reporting herein 2 cases of esophageal perforation in children seen very late (12 days and 40 days after foreign body impaction, complicated with severe sepsis, who were successfully operated upon with very good results.

  19. Identifying highly connected counties compensates for resource limitations when evaluating national spread of an invasive pathogen.

    Science.gov (United States)

    Sutrave, Sweta; Scoglio, Caterina; Isard, Scott A; Hutchinson, J M Shawn; Garrett, Karen A

    2012-01-01

    Surveying invasive species can be highly resource intensive, yet near-real-time evaluations of invasion progress are important resources for management planning. In the case of the soybean rust invasion of the United States, a linked monitoring, prediction, and communication network saved U.S. soybean growers approximately $200 M/yr. Modeling of future movement of the pathogen (Phakopsora pachyrhizi) was based on data about current disease locations from an extensive network of sentinel plots. We developed a dynamic network model for U.S. soybean rust epidemics, with counties as nodes and link weights a function of host hectarage and wind speed and direction. We used the network model to compare four strategies for selecting an optimal subset of sentinel plots, listed here in order of increasing performance: random selection, zonal selection (based on more heavily weighting regions nearer the south, where the pathogen overwinters), frequency-based selection (based on how frequently the county had been infected in the past), and frequency-based selection weighted by the node strength of the sentinel plot in the network model. When dynamic network properties such as node strength are characterized for invasive species, this information can be used to reduce the resources necessary to survey and predict invasion progress.

  20. Identifying highly connected counties compensates for resource limitations when evaluating national spread of an invasive pathogen.

    Directory of Open Access Journals (Sweden)

    Sweta Sutrave

    Full Text Available Surveying invasive species can be highly resource intensive, yet near-real-time evaluations of invasion progress are important resources for management planning. In the case of the soybean rust invasion of the United States, a linked monitoring, prediction, and communication network saved U.S. soybean growers approximately $200 M/yr. Modeling of future movement of the pathogen (Phakopsora pachyrhizi was based on data about current disease locations from an extensive network of sentinel plots. We developed a dynamic network model for U.S. soybean rust epidemics, with counties as nodes and link weights a function of host hectarage and wind speed and direction. We used the network model to compare four strategies for selecting an optimal subset of sentinel plots, listed here in order of increasing performance: random selection, zonal selection (based on more heavily weighting regions nearer the south, where the pathogen overwinters, frequency-based selection (based on how frequently the county had been infected in the past, and frequency-based selection weighted by the node strength of the sentinel plot in the network model. When dynamic network properties such as node strength are characterized for invasive species, this information can be used to reduce the resources necessary to survey and predict invasion progress.

  1. Modelling Management Practices in Viticulture while Considering Resource Limitations: The Dhivine Model.

    Directory of Open Access Journals (Sweden)

    Roger Martin-Clouaire

    Full Text Available Many farming-system studies have investigated the design and evaluation of crop-management practices with respect to economic performance and reduction in environmental impacts. In contrast, little research has been devoted to analysing these practices in terms of matching the recurrent context-dependent demand for resources (labour in particular with those available on the farm. This paper presents Dhivine, a simulation model of operational management of grape production at the vineyard scale. Particular attention focuses on representing a flexible plan, which organises activities temporally, the resources available to the vineyard manager and the process of scheduling and executing the activities. The model relies on a generic production-system ontology used in several agricultural production domains. The types of investigations that the model supports are briefly illustrated. The enhanced realism of the production-management situations simulated makes it possible to examine and understand properties of resource-constrained work-organisation strategies and possibilities for improving them.

  2. Car windshield fragments as cheap alternative glass beads for homogenization of Mycobacterium tuberculosis cultures in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    Ernest Afu Ochang

    2014-01-01

    Full Text Available Tuberculosis is a global health problem which has been compounded by the emergence and rapid spread of drug resistant strains. Phenotypic drug susceptibility testing of Mycobacterium tuberculosis usually requires homogenization of cultures using 3–5 mm glass beads. In resource limited settings, these important material may either not be readily available in the country as in our case requiring that one orders them from abroad or they may be too expensive. In both situations, this would impact on the usually lean budget. In our centre were we recently introduced tuberculosis culture and drug susceptibility testing using the Microscopic Observation Drug Susceptibility (MODS technique, we successfully used glass fragments from a broken car windshield obtained from a mechanic workshop to homogenize solid cultures to prepare positive controls. All cultures homogenized with these local beads gave consistent MODS results. The challenge of the limited availability of resources for research in resource limited settings can be met by adapting available materials to achieve results.

  3. Regional resources buffer the impact of functional limitations on perceived autonomy in older adults with multiple illnesses.

    Science.gov (United States)

    Schüz, Benjamin; Westland, Josh N; Wurm, Susanne; Tesch-Römer, Clemens; Wolff, Julia K; Warner, Lisa M; Schwarzer, Ralf

    2016-03-01

    Retaining perceptions of autonomy is a key component of successful aging. Perceived autonomy refers to the capacity to make and enact self-directed decisions. These perceptions are often threatened in older adults with multiple illnesses, when functional limitations resulting from these illnesses impede the enactment of self-directed decisions. Regional resources (in Germany specifically at the level of administrative districts) might counteract these impediments of autonomy. Economically stronger districts can provide more-concrete support resources for older adults, buffering the negative effect of functional limitations on self-perceived autonomy. This study assessed participants aged over 65 with 2 or more chronic conditions. In total, N = 287 provided data (Mage = 73.3, SD = 5.07), and n = 97 were women. Gross domestic product (GDP) per capita was used as a proxy measure of administrative district wealth in Germany. Hierarchical multilevel regression analyses with cross-level interactions were conducted. Results suggest that the detrimental effect of functional limitations on perceived autonomy is less pronounced for participants residing in higher GDP districts. Conversely, for participants in lower GDP districts, the effect is exacerbated. This finding suggests that districts with greater financial resources might be better able to invest in supports that promote and facilitate autonomy and, thus, provide a buffer against threats to individual perceived autonomy.

  4. Central-line-associated bloodstream infections in a resource-limited ...

    African Journals Online (AJOL)

    public sector NICU in South Africa (SA) and aims to identify risk factors for CLABSI ..... Predominantly antibiotic-resistant Gram-negative pathogens were isolated. ... Conclusion. Despite these limitations, to our knowledge, this study is the first.

  5. On the design of experiments for the study of extreme field limits in the ultra-relativistic interaction of electromagnetic waves with plasmas

    Science.gov (United States)

    Bulanov, Sergei V.; Esirkepov, Timur Z.; Hayashi, Yukio; Kando, Masaki; Kiriyama, Hiromitsu; Koga, James K.; Kondo, Kiminori; Kotaki, Hideyuki; Pirozhkov, Alexander S.; Bulanov, Stepan S.; Zhidkov, Alexei G.; Chen, Pisin; Neely, David; Kato, Yoshiaki; Narozhny, Nikolay B.; Korn, Georg

    2011-06-01

    The critical electric field of quantum electrodynamics, called also the Schwinger field, is so strong that it produces electron-positron pairs from vacuum, converting the energy of light into matter. Since the dawn of quantum electrodynamics, there has been a dream on how to reach it on Earth. With the rise of laser technology this field has become feasible through the construction of extremely high power lasers or/and with the sophisticated use of nonlinear processes in relativistic plasmas. This is one of the most attractive motivations for extremely high power laser development, i.e. producing matter from vacuum by pure light in fundamental process of quantum electrodynamics in the nonperturbative regime. Recently it has been realized that a laser with intensity well below the Schwinger limit can create an avalanche of electron-positron pairs similar to a discharge before attaining the Schwinger field. It has also been realized that the Schwinger limit can be reached using an appropriate configuration of laser beams. In experiments on the collision of laser light and high intensity electromagnetic pulses generated by relativistic flying mirrors, with electron bunches produced by a conventional accelerator and with laser wake field accelerated electrons the studying of extreme field limits in the nonlinear interaction of electromagnetic waves is proposed. The regimes of dominant radiation reaction, which completely changes the electromagnetic wave-matter interaction, will be revealed. This will result in a new powerful source of high brightness gamma-rays. A possibility of the demonstration of the electronpositron pair creation in vacuum via multi-photon processes can be realized. This will allow modeling under terrestrial laboratory conditions neutron star magnetospheres, cosmological gamma ray bursts and the Leptonic Era of the Universe.

  6. Field limit and nano-scale surface topography of superconducting radio-frequency cavity made of extreme type II superconductor

    CERN Document Server

    Kubo, Takayuki

    2014-01-01

    The field limit of superconducting radio-frequency cavity made of type II superconductor with a large Ginzburg-Landau parameter is studied with taking effects of nano-scale surface topography into account. If the surface is ideally flat, the field limit is imposed by the superheating field. On the surface of cavity, however, nano-defects almost continuously distribute and suppress the superheating field everywhere. The field limit is imposed by an effective superheating field given by the product of the superheating field for ideal flat surface and a suppression factor that contains effects of nano-defects. A nano-defect is modeled by a triangular groove with a depth smaller than the penetration depth. An analytical formula for the suppression factor of bulk and multilayer superconductors are derived in the framework of the London theory. As an immediate application, the suppression factor of the dirty Nb processed by the electropolishing is evaluated by using results of surface topographic study. The estimat...

  7. Scheduling sampling to maximize information about time dependence in experiments with limited resources

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Christiansen, Lasse Engbo

    2013-01-01

    Looking for periodicity in sampled data requires that periods (lags) of different length are represented in the sampling plan. We here present a method to assist in planning of temporal studies with sparse resources, which optimizes the number of observed time lags for a fixed amount of samples...... within a fixed time window given a maximum time lag of interest. The method can also optimize the temporal sampling specifically for situations where samples are at risk of being rescheduled due to otherwise unpredictable events such as weather, faulty equipment, etc. The method is based on the framework...

  8. Biotechnological production of enantiomeric pure lactic acid from renewable resources: recent achievements, perspectives, and limits.

    Science.gov (United States)

    Okano, Kenji; Tanaka, Tsutomu; Ogino, Chiaki; Fukuda, Hideki; Kondo, Akihiko

    2010-01-01

    Lactic acid (LA) is an important and versatile chemical that can be produced from renewable resources such as biomass. LA is used in the food, pharmaceutical, and polymers industries and is produced by microorganism fermentation; however, most microorganisms cannot directly utilize biomass such as starchy materials and cellulose. Here, we summarize LA production using several kinds of genetically modified microorganisms, such as LA bacteria, Escherichia coli, Corynebacterium glutamicum, and yeast. Using gene manipulation and metabolic engineering, the yield and optical purity of LA produced from biomass has been significantly improved. In this review, the drawbacks as well as improvements of LA production by fermentation is discussed.

  9. The model of localized business community economic development under limited financial resources: computer model and experiment

    Directory of Open Access Journals (Sweden)

    Berg Dmitry

    2016-01-01

    Full Text Available Globalization processes now affect and are affected by most of organizations, different type resources, and the natural environment. One of the main restrictions initiated by these processes is the financial one: money turnover in global markets leads to its concentration in the certain financial centers, and local business communities suffer from the money lack. This work discusses the advantages of complementary currency introduction into a local economics. By the computer simulation with the engineered program model and the real economic experiment it was proved that the complementary currency does not compete with the traditional currency, furthermore, it acts in compliance with it, providing conditions for the sustainable business community development.

  10. Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

    Directory of Open Access Journals (Sweden)

    Soto Giselle

    2008-11-01

    Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

  11. Effect of limiting ankle-dorsiflexion range of motion on lower extremity kinematics and muscle-activation patterns during a squat.

    Science.gov (United States)

    Macrum, Elisabeth; Bell, David Robert; Boling, Michelle; Lewek, Michael; Padua, Darin

    2012-05-01

    Limitations in gastrocnemius/soleus flexibility that restrict ankle dorsiflexion during dynamic tasks have been reported in individuals with patellofemoral pain (PFP) and are theorized to play a role in its development. To determine the effect of restricted ankle-dorsiflexion range of motion (ROM) on lower extremity kinematics and muscle activity (EMG) during a squat. The authors hypothesized that restricted ankle-dorsiflexion ROM would alter knee kinematics and lower extremity EMG during a squat. Cross-sectional. 30 healthy, recreationally active individuals without a history of lower extremity injury. Each participant performed 7 trials of a double-leg squat under 2 conditions: a no-wedge condition (NW) with the foot flat on the floor and a wedge condition (W) with a 12° forefoot angle to simulate reduced plantar-flexor flexibility. 3-dimensional hip and knee kinematics, medial knee displacement (MKD), and ankle-dorsiflexion angle. EMG of vastus medialis oblique (VMO), vastus lateralis (VL), lateral gastrocnemius (LG), and soleus (SOL). One-way repeated-measures ANOVAs were performed to determine differences between the W and NW conditions. Compared with the NW condition, the wedge produced decreased peak knee flexion (P .05). Altering ankle-dorsiflexion starting position during a double-leg squat resulted in increased knee valgus and MKD, as well as decreased quadriceps activation and increased soleus activation. These changes are similar to those seen in people with PFP.

  12. Packaging health services when resources are limited: the example of a cervical cancer screening visit.

    Directory of Open Access Journals (Sweden)

    Jane J Kim

    2006-11-01

    Full Text Available BACKGROUND: Increasing evidence supporting the value of screening women for cervical cancer once in their lifetime, coupled with mounting interest in scaling up successful screening demonstration projects, present challenges to public health decision makers seeking to take full advantage of the single-visit opportunity to provide additional services. We present an analytic framework for packaging multiple interventions during a single point of contact, explicitly taking into account a budget and scarce human resources, constraints acknowledged as significant obstacles for provision of health services in poor countries. METHODS AND FINDINGS: We developed a binary integer programming (IP model capable of identifying an optimal package of health services to be provided during a single visit for a particular target population. Inputs to the IP model are derived using state-transition models, which compute lifetime costs and health benefits associated with each intervention. In a simplified example of a single lifetime cervical cancer screening visit, we identified packages of interventions among six diseases that maximized disability-adjusted life years (DALYs averted subject to budget and human resource constraints in four resource-poor regions. Data were obtained from regional reports and surveys from the World Health Organization, international databases, the published literature, and expert opinion. With only a budget constraint, interventions for depression and iron deficiency anemia were packaged with cervical cancer screening, while the more costly breast cancer and cardiovascular disease interventions were not. Including personnel constraints resulted in shifting of interventions included in the package, not only across diseases but also between low- and high-intensity intervention options within diseases. CONCLUSIONS: The results of our example suggest several key themes: Packaging other interventions during a one-time visit has the

  13. Maternal health interventions in resource limited countries: a systematic review of packages, impacts and factors for change

    Science.gov (United States)

    2011-01-01

    Background The burden of maternal mortality in resource limited countries is still huge despite being at the top of the global public health agenda for over the last 20 years. We systematically reviewed the impacts of interventions on maternal health and factors for change in these countries. Methods A systematic review was carried out using the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Articles published in the English language reporting on implementation of interventions, their impacts and underlying factors for maternal health in resource limited countries in the past 23 years were searched from PubMed, Popline, African Index Medicus, internet sources including reproductive health gateway and Google, hand-searching, reference lists and grey literature. Results Out of a total of 5084 articles resulting from the search only 58 qualified for systematic review. Programs integrating multiple interventions were more likely to have significant positive impacts on maternal outcomes. Training in emergency obstetric care (EmOC), placement of care providers, refurbishment of existing health facility infrastructure and improved supply of drugs, consumables and equipment for obstetric care were the most frequent interventions integrated in 52% - 65% of all 54 reviewed programs. Statistically significant reduction of maternal mortality ratio and case fatality rate were reported in 55% and 40% of the programs respectively. Births in EmOC facilities and caesarean section rates increased significantly in 71% - 75% of programs using these indicators. Insufficient implementation of evidence-based interventions in resources limited countries was closely linked to a lack of national resources, leadership skills and end-users factors. Conclusions This article presents a list of evidenced-based packages of interventions for maternal health, their impacts and factors for change in resource limited countries. It indicates that no single

  14. Maternal health interventions in resource limited countries: a systematic review of packages, impacts and factors for change.

    Science.gov (United States)

    Nyamtema, Angelo S; Urassa, David P; van Roosmalen, Jos

    2011-04-17

    The burden of maternal mortality in resource limited countries is still huge despite being at the top of the global public health agenda for over the last 20 years. We systematically reviewed the impacts of interventions on maternal health and factors for change in these countries. A systematic review was carried out using the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Articles published in the English language reporting on implementation of interventions, their impacts and underlying factors for maternal health in resource limited countries in the past 23 years were searched from PubMed, Popline, African Index Medicus, internet sources including reproductive health gateway and Google, hand-searching, reference lists and grey literature. Out of a total of 5084 articles resulting from the search only 58 qualified for systematic review. Programs integrating multiple interventions were more likely to have significant positive impacts on maternal outcomes. Training in emergency obstetric care (EmOC), placement of care providers, refurbishment of existing health facility infrastructure and improved supply of drugs, consumables and equipment for obstetric care were the most frequent interventions integrated in 52%-65% of all 54 reviewed programs. Statistically significant reduction of maternal mortality ratio and case fatality rate were reported in 55% and 40% of the programs respectively. Births in EmOC facilities and caesarean section rates increased significantly in 71%-75% of programs using these indicators. Insufficient implementation of evidence-based interventions in resources limited countries was closely linked to a lack of national resources, leadership skills and end-users factors. This article presents a list of evidenced-based packages of interventions for maternal health, their impacts and factors for change in resource limited countries. It indicates that no single magic bullet intervention exists for

  15. Maternal health interventions in resource limited countries: a systematic review of packages, impacts and factors for change

    Directory of Open Access Journals (Sweden)

    Urassa David P

    2011-04-01

    Full Text Available Abstract Background The burden of maternal mortality in resource limited countries is still huge despite being at the top of the global public health agenda for over the last 20 years. We systematically reviewed the impacts of interventions on maternal health and factors for change in these countries. Methods A systematic review was carried out using the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA. Articles published in the English language reporting on implementation of interventions, their impacts and underlying factors for maternal health in resource limited countries in the past 23 years were searched from PubMed, Popline, African Index Medicus, internet sources including reproductive health gateway and Google, hand-searching, reference lists and grey literature. Results Out of a total of 5084 articles resulting from the search only 58 qualified for systematic review. Programs integrating multiple interventions were more likely to have significant positive impacts on maternal outcomes. Training in emergency obstetric care (EmOC, placement of care providers, refurbishment of existing health facility infrastructure and improved supply of drugs, consumables and equipment for obstetric care were the most frequent interventions integrated in 52% - 65% of all 54 reviewed programs. Statistically significant reduction of maternal mortality ratio and case fatality rate were reported in 55% and 40% of the programs respectively. Births in EmOC facilities and caesarean section rates increased significantly in 71% - 75% of programs using these indicators. Insufficient implementation of evidence-based interventions in resources limited countries was closely linked to a lack of national resources, leadership skills and end-users factors. Conclusions This article presents a list of evidenced-based packages of interventions for maternal health, their impacts and factors for change in resource limited countries

  16. A Life-cycle Approach to Improve the Sustainability of Rural Water Systems in Resource-Limited Countries

    Directory of Open Access Journals (Sweden)

    Nicholas Stacey

    2012-11-01

    Full Text Available A WHO and UNICEF joint report states that in 2008, 884 million people lacked access to potable drinking water. A life-cycle approach to develop potable water systems may improve the sustainability for such systems, however, a review of the literature shows that such an approach has primarily been used for urban systems located in resourced countries. Although urbanization is increasing globally, over 40 percent of the world’s population is currently rural with many considered poor. In this paper, we present a first step towards using life-cycle assessment to develop sustainable rural water systems in resource-limited countries while pointing out the needs. For example, while there are few differences in costs and environmental impacts for many improved rural water system options, a system that uses groundwater with community standpipes is substantially lower in cost that other alternatives with a somewhat lower environmental inventory. However, a LCA approach shows that from institutional as well as community and managerial perspectives, sustainability includes many other factors besides cost and environment that are a function of the interdependent decision process used across the life cycle of a water system by aid organizations, water user committees, and household users. These factors often present the biggest challenge to designing sustainable rural water systems for resource-limited countries.

  17. Solution electrostatic levitator for measuring surface properties and bulk structures of an extremely supersaturated solution drop above metastable zone width limit

    Science.gov (United States)

    Lee, Sooheyong; Jo, Wonhyuk; Cho, Yong chan; Lee, Hyun Hwi; Lee, Geun Woo

    2017-05-01

    We report on the first integrated apparatus for measuring surface and thermophysical properties and bulk structures of a highly supersaturated solution by combining electrostatic levitation with real-time laser/x-ray scattering. Even today, a proper characterization of supersaturated solutions far above their solubility limits is extremely challenging because heterogeneous nucleation sites such as container walls or impurities readily initiate crystallization before the measurements can be performed. In this work, we demonstrate simultaneous measurements of drying kinetics and surface tension of a potassium dihydrogen phosphate (KH2PO4) aqueous solution droplet and its bulk structural evolution beyond the metastable zone width limit. Our experimental finding shows that the noticeable changes of the surface properties are accompanied by polymerizations of hydrated monomer clusters. The novel electrostatic levitation apparatus presented here provides an effective means for studying a wide range of highly concentrated solutions and liquids in deep metastable states.

  18. The antikick strikes back: recoil velocities for nearly-extremal binary black hole mergers in the test-mass limit

    CERN Document Server

    Nagar, Alessandro; Bernuzzi, Sebastiano; Zenginoğlu, Anıl

    2014-01-01

    Gravitational waves emitted from a generic binary black-hole merger carry away linear momentum anisotropically, resulting in a gravitational recoil, or "kick", of the center of mass. For certain merger configurations the time evolution of the magnitude of the kick velocity has a local maximum followed by a sudden drop. Perturbative studies of this "antikick" in a limited range of black hole spins have found that the antikick decreases for retrograde orbits as a function of negative spin. We analyze this problem using a recently developed code to evolve gravitational perturbations from a point-particle in Kerr spacetime driven by an effective-one-body resummed radiation reaction force at linear order in the mass ratio $\

  19. Time as a limited resource: Communication Strategy in Mobile Phone Networks

    CERN Document Server

    Miritello, Giovanna; Lara, Rubén; Martínez-López, Rocío; Roberts, Sam G B; Dunbar, Robin I M

    2013-01-01

    We used a large database of 9 billion calls from 20 million mobile users to examine the relationships between aggregated time spent on the phone, personal network size, tie strength and the way in which users distributed their limited time across their network (disparity). Compared to those with smaller networks, those with large networks did not devote proportionally more time to communication and had on average weaker ties (as measured by time spent communicating). Further, there were not substantially different levels of disparity between individuals, in that mobile users tend to distribute their time very unevenly across their network, with a large proportion of calls going to a small number of individuals. Together, these results suggest that there are time constraints which limit tie strength in large personal networks, and that even high levels of mobile communication do not fundamentally alter the disparity of time allocation across networks.

  20. Proposing evidence-based strategies to strengthen implementation of healthcare reform in resource-limited settings: a summative analysis.

    Science.gov (United States)

    Manyazewal, Tsegahun; Oosthuizen, Martha J; Matlakala, Mokgadi C

    2016-09-20

    Many resource-limited countries have adopted and implemented healthcare reform to improve the quality of healthcare, but few have had much impact and strategies in support of these efforts remain limited. We aimed to explore and propose evidence-based strategies to strengthen implementation of healthcare reform in resource-limited settings. Descriptive and exploratory designs in two phases. Phase I involved assessing the effectiveness of the healthcare reform implemented in Ethiopia in the form of business process reengineering, with evidence compiled from healthcare professionals through a self-administered questionnaire; and phase II involved proposing strategies and seeking consensus from experts using Delphi method. Public hospitals in central Ethiopia. 406 healthcare professionals and 10 senior health policy experts. The healthcare reform that we evaluated was able to restructure hospital departments into case teams, with the goal of adopting a 'one-stop shopping' approach. However, shortages of critical infrastructure, furniture and supplies and job dissatisfaction continued to hamper the system. The most important predictors that influenced implementation of the reform were financial resources, top management commitment and support, collaborative working environment and information technology (IT). Five strategies with 14 operational objectives and 67 potential interventions that could strengthen the reform are proposed based on their strategic priority, which are as follows: reinforce patient-centred quality of care services; foster a healthy and respectful workforce environment; efficient and accountable leadership and governance; efficient use of hospital financing and maximise innovations and the use of health technologies. Effective implementation of healthcare reform remained a challenge for governments in resource-limited settings. Resilient operational, clinical and governance functions of health systems, as well as a motivated and committed health

  1. Limited and time-delayed internal resource allocation generates oscillations and chaos in the dynamics of citrus crops

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Xujun, E-mail: yexujun@cc.hirosaki-u.ac.jp [College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058 (China); Faculty of Agriculture and Life Sciences, Hirosaki University, Aomori 036-8561 (Japan); Sakai, Kenshi, E-mail: ken@cc.tuat.ac.jp [Environmental and Agricultural Engineering Department, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan)

    2013-12-15

    Alternate bearing or masting is a yield variability phenomenon in perennial crops. The complex dynamics in this phenomenon have stimulated much ecological research. Motivated by data from an eight-year experiment with forty-eight individual trees, we explored the mechanism inherent to these dynamics in Satsuma mandarin (Citrus unshiu Marc.). By integrating high-resolution imaging technology, we found that the canopy structure and reproduction output of individual citrus crops are mutually dependent on each other. Furthermore, it was revealed that the mature leaves in early season contribute their energy to the fruiting of the current growing season, whereas the younger leaves show a delayed contribution to the next growing season. We thus hypothesized that the annual yield variability might be caused by the limited and time-delayed resource allocation in individual plants. A novel lattice model based on this hypothesis demonstrates that this pattern of resource allocation will generate oscillations and chaos in citrus yield.

  2. The role of atmospheric diagnosis and Big Data science in improving hydroclimatic extreme prediction and the merits of climate informed prediction for future water resources management

    Science.gov (United States)

    Lu, Mengqian; Lall, Upmanu

    2017-04-01

    extreme rainfall events in the mid-latitudes, tropical moisture sources related to strong convection from equatorial oceans were identified together with atmospheric circulation conditions that in favor of consistent transport and convergence of moisture [Lu et al., 2013; Lu and Lall, 2016]. Further, [Lu et al., 2016a] linked the influence of the slowly changing oceanic boundary conditions with the development of the global atmospheric circulation and showed that (1) strong convection over the oceans and the atmospheric moisture transport and flow convergence indicated by atmospheric pressure fields can determine where and when extreme precipitation occurs; and (2) the time-lagged spatial relationship between teleconnected oceanic signals and synoptic atmospheric circulations can improve the predictability of extreme precipitation globally over the next 30 days; such a forecast would be potentially very useful for flood preparation at a lead time that is well beyond the lead time of meteorological forecasts, and it corresponds to a gap in the predictability between quantitative precipitation forecasts and seasonal-to-interannual climate prediction. Lastly, we will demonstrate our most recent results showing the merits of utilizing climate informed forecasts for water resources management, considering irrigation supply, hydropower and flood control, with marked-based financial instruments [Lu et al., 2016b].

  3. Review of the safety, efficacy, and pharmacokinetics of elvitegravir with an emphasis on resource-limited settings

    Directory of Open Access Journals (Sweden)

    Lee JSF

    2012-01-01

    Full Text Available Janice Soo Fern Lee1, Alexandra Calmy1,2, Isabelle Andrieux-Meyer1, Nathan Ford1,31Médecins Sans Frontières, 2HIV/AIDS Unit, Infectious Disease Service, Geneva University Hospital, Geneva, Switzerland; 3Centre for Infectious Disease Epidemiology and Research, University of Cape Town, South AfricaAbstract: Integrase inhibitors represent an important new class of antiretroviral drugs. Elvitegravir, the second available integrase inhibitor to be submitted for regulatory approval appears to be a promising once-daily agent when combined with other antiretroviral drugs. Elvitegravir has demonstrated good efficacy and safety, with minimal side effects and no specific requirements in terms of laboratory monitoring. In addition, elvitegravir is available as a fixed-dose combination. However, the drug requires boosting and this leads to a number of drug–drug interactions and necessary dose adjustment when dosing with certain drugs, including dose reduction in the presence of atazanavir, lopinavir, rifabutin, and ketoconazole, and dose increase for ethinyl estradiol when co-administered with boosted elvitegravir. The main advantage of elvitegravir lies in its potential to be administered as a once-daily, single pill. Limitations include dose adjustment requirements, a relatively low genetic barrier to resistance, high price, and lack of data for use in children. Clinical trials addressing specific challenges encountered in resources-limited settings should be encouraged.Keywords: elvitegravir, efficacy, safety, resistance, resource-limited settings

  4. Study on the Strategies for the Soil and Water Resource Con-servation of Slopeland in Taiwan in Response to the Extreme Climate

    Science.gov (United States)

    Huang, Wen-Cheng

    2014-05-01

    Global climate change results in extreme weather, especially ex-treme precipitation in Taiwan. Though the total amount of precipi-tation remains unchanged, the frequency of rainfall return period increases which affects slopeland and causes sediment disaster. In Taiwan, slopeland occupies about 73% of national territory. Under harsh environmental stress, soil and water conservation of slope-land becomes more important. In response to the trends of global-ization impacts of climate change, long term strategic planning be-comes more necessary. This study reviewed international practices and decision making process about soil and water conservation of slopeland; and conducted the compilation and analysis of water and soil conservation related research projects in Taiwan within the past five years. It is necessary for Taiwan to design timely adaptive strategies about conducting the all-inclusive conservation of na-tional territory, management and business operation of watershed based on the existing regulation with the effects of extreme weather induced by climate change and the changes of social-economic en-vironments. In order to realize the policy vision of "Under the premise of multiple uses, operating the sustainable business and management of the water and soil resources in the watershed through territorial planning in response to the climate and so-cial-economic environment change". This study concluded the future tasks for soil and water con-servation: 1.Design and timely amend strategies for soil and wand water conservation in response to extreme weather. 2. Strengthen the planning and operating of the land management and integrated conservation of the water and soil resources of key watershed. 3. Manage and operate the prevention of debris flow disaster and large-scale landslide. 4. Formulate polices, related regulations and assessment indicators of soil and water conservation. 5. Maintain the biodiversity of the slopeland and reduce the ecological footprint

  5. Biomedical laboratory science education: standardising teaching content in resource-limited countries

    Directory of Open Access Journals (Sweden)

    Wendy Arneson

    2013-03-01

    Full Text Available Background: There is a worldwide shortage of qualified laboratory personnel to provide adequate testing for the detection and monitoring of diseases. In an effort to increase laboratory capacity in developing countries, new skills have been introduced into laboratory services. Curriculum revision with a focus on good laboratory practice is an important aspect of supplying entry-level graduates with the competencies needed to meet the current needs.Objectives: Gaps in application and problem-solving competencies of newly graduated laboratory personnel were discovered in Ethiopia, Tanzania and Kenya. New medical laboratory teaching content was developed in Ethiopia, Tanzania and Kenya using national instructors, tutors, and experts and consulting medical laboratory educators from the United States of America (USA.Method: Workshops were held in Ethiopia to create standardised biomedical laboratory science (BMLS lessons based on recently-revised course objectives with an emphasis on application of skills. In Tanzania, course-module teaching guides with objectives were developed based on established competency outcomes and tasks. In Kenya, example interactive presentations and lesson plans were developed by the USA medical laboratory educators prior to the workshop to serve as resources and templates for the development of lessons within the country itself.Results: The new teaching materials were implemented and faculty, students and other stakeholders reported successful outcomes.Conclusions: These approaches to updating curricula may be helpful as biomedical laboratory schools in other countries address gaps in the competencies of entry-level graduates.

  6. The impact of antiretroviral therapy in resource-limited settings and current HIV therapeutics.

    Science.gov (United States)

    Kumarasamy, N

    2016-04-01

    Four million people of the global total of 35 million with HIV infection are from South-East Asia. ART is currently utilized by 15 million people and has led to a dramatic decline in the mortality rate, including those in low- and middle-income countries. A reduction in sexually transmitted HIV and in comorbidities including tuberculosis has also followed. Current recommendations for the initiation of antiretroviral therapy in people who are HIV+ are essentially to initiate ART irrespective of CD4 cell count and clinical stage. The frequency of HIV testing should be culturally specific and based on the HIV incidence in different key populations but phasing in viral load technology in LMIC is an urgent priority and this needs resources and capacity. With the availability of simplified potent ART regimens, persons with HIV now live longer. The recent WHO treatment guidelines recommending routine HIV testing and earlier initiation of treatment should be the stepping stone for ending the AIDS epidemic and to meet the UNAIDS mission of 90*90*90.

  7. The limits of human development and the use of energy and natural resources

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Rubens A.; Mattos, Cristiano R.; Balestieri, Jose A. [Energy Department, UNESP - Campus de Guaratingueta, Avenida Doutor Ariberto Pereira da Cunha, 333, P.O. Box 205, 12516-410, Guaratingueta, SP (Brazil)

    2006-06-15

    The development of nations is an unquestionable requirement. A lot of challenges concerning health, education and economy are present. A discussion on these development models has occupied the minds of decision makers in recent years. When energy supply and demand is considered, the situation becomes critical and the crucial question is: how to improve the quality of life of developing countries based on available models of development that are related to the life style of developed countries, for which the necessary use and waste of energy are present? How much energy is essential to humanity for not so as to endangering the survival conditions of future generations? The human development index (HDI) establishes the relationship among energy use, economic growth and social growth. Here it can be seen that 75% of the world population has a significant energy consumption potential. This is a strong reason to consider that the sustainable development concepts on energy policies are strategic to the future of the planet. This paper deals with the importance of seeking alternative development models for human development balance, natural resources conservation and environment through rational energy use concepts. (author)

  8. Separating limits on preparation versus online processing in multitasking paradigms: Evidence for resource models.

    Science.gov (United States)

    Mittelstädt, Victor; Miller, Jeff

    2017-01-01

    We conducted 2 multitasking experiments to examine the finding that first-task reaction times (RTs) are slower in the psychological refractory period (PRP) paradigm than in the prioritized processing (PP) paradigm. To see whether this difference between the 2 paradigms could be explained entirely by differences in first-task preparation, which would be consistent with the standard response selection bottleneck (RSB) model for multitasking interference, we compared the size of this difference for trials in which a second-task stimulus actually occurred against the size of the difference for trials without any second-task stimulus. The slowing of first-task RTs in the PRP paradigm relative to the PP paradigm was larger when the second-task stimulus appeared than when it did not, indicating that the difference cannot be explained entirely by between-paradigm differences in first-task preparation. Instead, the results suggest that the slowing of first-task RTs in the PRP paradigm relative to the PP paradigm is partly because of differences between paradigms in the online reallocation of processing capacity to tasks. Thus, the present results provide new evidence supporting resource models over the RSB model. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. The International Society of Nephrology (ISN). Roles & challenges in Africa and other resource-limited communities.

    Science.gov (United States)

    Feehally, John

    ISN (the International Society of Nephrology) is a global organization with more than 9,000 members in 130 countries. The ISN's mission is to "advance the diagnosis, treatment, and prevention of kidney diseases in the developing and developed world". ISN delivers this mission in low-resource settings through its five education and training programs available exclusively to low- and middle-income countries. These programs are designed to enable sustainable growth in capacity in nephrology and related disciplines to provide the basis for the improvement of care for kidney patients worldwide. ISN also directs its efforts towards advocacy for kidney health and kidney care, seeking to increase understanding of kidney disease among the general population, health professionals, and health policy makers. Such advocacy is challenging because of the complexity of kidney health messages; there is a need to emphasize affordable healthcare solutions for prevention and treatment of acute kidney injury (AKI), as well as the prevention and management of chronic kidney disease (CKD), and the provision of renal replacement therapy (both chronic dialysis and kidney transplantation) that is both affordable and ethically acceptable.

  10. Can we predict neuropathy risk before stavudine prescription in a resource-limited setting?

    Science.gov (United States)

    Affandi, Jacquita S; Price, Patricia; Imran, Darma; Yunihastuti, Evy; Djauzi, Samsuridjal; Cherry, Catherine L

    2008-10-01

    A toxic sensory neuropathy associated with exposure to inexpensive nucleoside analogue reverse transcriptase inhibitors (NRTIs) [particularly stavudine (d4T)] causes dilemmas in the management of patients with HIV, especially in resource-poor settings. Here patients (n = 96) attending Pokdisus AIDS Clinic at the Cipto Mangunkusumo Hospital, Jakarta who had been treated with d4T were screened for symptomatic neuropathy. Clinical, demographic, and genetic factors were considered as possible neuropathy risk factors. DNA from saliva was used to examine alleles of TNFA-308, BAT1 (intron 10), TNFA-1031, IL1A+4845, and IL12B (3' UTR). The prevalence of neuropathy (symptoms and signs) was 34%. On multivariate analysis, neuropathy following d4T exposure was associated with increasing age, increasing height, and TNFA-1031*2 (model p = 0.0009). Isoniazid exposure (present in 56% of patients) was not associated with neuropathy in this cohort, where all patients had received pyridoxine coadministration. These data suggest that a simple algorithm based on patient age, height, and TNF genotype could be used to predict the individual's risk of symptomatic neuropathy prior to prescription of d4T.

  11. Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity

    Directory of Open Access Journals (Sweden)

    Porté Annabel J

    2011-11-01

    Full Text Available Abstract Background To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Results Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. Conclusions The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree

  12. Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity.

    Science.gov (United States)

    Porté, Annabel J; Lamarque, Laurent J; Lortie, Christopher J; Michalet, Richard; Delzon, Sylvain

    2011-11-24

    To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree species, contributes to its spread in European resource

  13. A multi-scale distribution model for non-equilibrium populations suggests resource limitation in an endangered rodent.

    Directory of Open Access Journals (Sweden)

    William T Bean

    Full Text Available Species distributions are known to be limited by biotic and abiotic factors at multiple temporal and spatial scales. Species distribution models, however, frequently assume a population at equilibrium in both time and space. Studies of habitat selection have repeatedly shown the difficulty of estimating resource selection if the scale or extent of analysis is incorrect. Here, we present a multi-step approach to estimate the realized and potential distribution of the endangered giant kangaroo rat. First, we estimate the potential distribution by modeling suitability at a range-wide scale using static bioclimatic variables. We then examine annual changes in extent at a population-level. We define "available" habitat based on the total suitable potential distribution at the range-wide scale. Then, within the available habitat, model changes in population extent driven by multiple measures of resource availability. By modeling distributions for a population with robust estimates of population extent through time, and ecologically relevant predictor variables, we improved the predictive ability of SDMs, as well as revealed an unanticipated relationship between population extent and precipitation at multiple scales. At a range-wide scale, the best model indicated the giant kangaroo rat was limited to areas that received little to no precipitation in the summer months. In contrast, the best model for shorter time scales showed a positive relation with resource abundance, driven by precipitation, in the current and previous year. These results suggest that the distribution of the giant kangaroo rat was limited to the wettest parts of the drier areas within the study region. This multi-step approach reinforces the differing relationship species may have with environmental variables at different scales, provides a novel method for defining "available" habitat in habitat selection studies, and suggests a way to create distribution models at spatial and

  14. Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity

    Science.gov (United States)

    2011-01-01

    Background To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Results Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. Conclusions The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree species, contributes to its spread

  15. Sankofa pediatric HIV disclosure intervention cyber data management: building capacity in a resource-limited setting and ensuring data quality.

    Science.gov (United States)

    Catlin, Ann Christine; Fernando, Sumudinie; Gamage, Ruwan; Renner, Lorna; Antwi, Sampson; Tettey, Jonas Kusah; Amisah, Kofi Aikins; Kyriakides, Tassos; Cong, Xiangyu; Reynolds, Nancy R; Paintsil, Elijah

    2015-01-01

    Prevalence of pediatric HIV disclosure is low in resource-limited settings. Innovative, culturally sensitive, and patient-centered disclosure approaches are needed. Conducting such studies in resource-limited settings is not trivial considering the challenges of capturing, cleaning, and storing clinical research data. To overcome some of these challenges, the Sankofa pediatric disclosure intervention adopted an interactive cyber infrastructure for data capture and analysis. The Sankofa Project database system is built on the HUBzero cyber infrastructure ( https://hubzero.org ), an open source software platform. The hub database components support: (1) data management - the "databases" component creates, configures, and manages database access, backup, repositories, applications, and access control; (2) data collection - the "forms" component is used to build customized web case report forms that incorporate common data elements and include tailored form submit processing to handle error checking, data validation, and data linkage as the data are stored to the database; and (3) data exploration - the "dataviewer" component provides powerful methods for users to view, search, sort, navigate, explore, map, graph, visualize, aggregate, drill-down, compute, and export data from the database. The Sankofa cyber data management tool supports a user-friendly, secure, and systematic collection of all data. We have screened more than 400 child-caregiver dyads and enrolled nearly 300 dyads, with tens of thousands of data elements. The dataviews have successfully supported all data exploration and analysis needs of the Sankofa Project. Moreover, the ability of the sites to query and view data summaries has proven to be an incentive for collecting complete and accurate data. The data system has all the desirable attributes of an electronic data capture tool. It also provides an added advantage of building data management capacity in resource-limited settings due to its

  16. Probing the limitations of isotropic pair potentials to produce ground-state structural extremes via inverse statistical mechanics.

    Science.gov (United States)

    Zhang, G; Stillinger, F H; Torquato, S

    2013-10-01

    Inverse statistical-mechanical methods have recently been employed to design optimized short-range radial (isotropic) pair potentials that robustly produce novel targeted classical ground-state many-particle configurations. The target structures considered in those studies were low-coordinated crystals with a high degree of symmetry. In this paper, we further test the fundamental limitations of radial pair potentials by targeting crystal structures with appreciably less symmetry, including those in which the particles have different local structural environments. These challenging target configurations demanded that we modify previous inverse optimization techniques. In particular, we first find local minima of a candidate enthalpy surface and determine the enthalpy difference ΔH between such inherent structures and the target structure. Then we determine the lowest positive eigenvalue λ(0) of the Hessian matrix of the enthalpy surface at the target configuration. Finally, we maximize λ(0)ΔH so that the target structure is both locally stable and globally stable with respect to the inherent structures. Using this modified optimization technique, we have designed short-range radial pair potentials that stabilize the two-dimensional kagome crystal, the rectangular kagome crystal, and rectangular lattices, as well as the three-dimensional structure of the CaF(2) crystal inhabited by a single-particle species. We verify our results by cooling liquid configurations to absolute zero temperature via simulated annealing and ensuring that such states have stable phonon spectra. Except for the rectangular kagome structure, all of the target structures can be stabilized with monotonic repulsive potentials. Our work demonstrates that single-component systems with short-range radial pair potentials can counterintuitively self-assemble into crystal ground states with low symmetry and different local structural environments. Finally, we present general principles that offer

  17. When Big Data Fails! Relative success of adaptive agents using coarse-grained information to compete for limited resources

    CERN Document Server

    Sasidevan, V; Sinha, Sitabhra

    2016-01-01

    The recent trend for acquiring big data assumes that possessing quantitatively more and qualitatively finer data necessarily provides an advantage that may be critical in competitive situations. Using a model complex adaptive system where agents compete for a limited resource using information coarse-grained to different levels, we show that agents having access to more and better data can perform worse than others in certain situations. The relation between information asymmetry and individual payoffs is seen to be complex, depending on the composition of the population of competing agents.

  18. Single incision cholecystectomy using a clipless technique with LigaSure in a resource limited environment: The Bahamas experience

    Directory of Open Access Journals (Sweden)

    Ross O. Downes

    2015-01-01

    Conclusions: SILC is a safe and feasible technique for operating with scarless outcomes and reducing perioperative discomfort at the same time. The GelPOINTTM is a safe and feasible platform to be used. The procedure can be accomplished using regular instruments and laparoscope. Curved instruments and a bariatric length laparoscope may make the procedure easier and result in greater time saving. The addition of LigaSure™ decreases the complexity of the operation, decreases operative time and blood loss. The technique is economical in a resource-limited environment.

  19. Improving antiretroviral therapy adherence in resource-limited settings at scale: a discussion of interventions and recommendations.

    Science.gov (United States)

    Haberer, Jessica E; Sabin, Lora; Amico, K Rivet; Orrell, Catherine; Galárraga, Omar; Tsai, Alexander C; Vreeman, Rachel C; Wilson, Ira; Sam-Agudu, Nadia A; Blaschke, Terrence F; Vrijens, Bernard; Mellins, Claude A; Remien, Robert H; Weiser, Sheri D; Lowenthal, Elizabeth; Stirratt, Michael J; Sow, Papa Salif; Thomas, Bruce; Ford, Nathan; Mills, Edward; Lester, Richard; Nachega, Jean B; Bwana, Bosco Mwebesa; Ssewamala, Fred; Mbuagbaw, Lawrence; Munderi, Paula; Geng, Elvin; Bangsberg, David R

    2017-01-01

    Introduction: Successful population-level antiretroviral therapy (ART) adherence will be necessary to realize both the clinical and prevention benefits of antiretroviral scale-up and, ultimately, the end of AIDS. Although many people living with HIV are adhering well, others struggle and most are likely to experience challenges in adherence that may threaten virologic suppression at some point during lifelong therapy. Despite the importance of ART adherence, supportive interventions have generally not been implemented at scale. The objective of this review is to summarize the recommendations of clinical, research, and public health experts for scalable ART adherence interventions in resource-limited settings. Methods: In July 2015, the Bill and Melinda Gates Foundation convened a meeting to discuss the most promising ART adherence interventions for use at scale in resource-limited settings. This article summarizes that discussion with recent updates. It is not a systematic review, but rather provides practical considerations for programme implementation based on evidence from individual studies, systematic reviews, meta-analyses, and the World Health Organization Consolidated Guidelines for HIV, which include evidence from randomized controlled trials in low- and middle-income countries. Interventions are categorized broadly as education and counselling; information and communication technology-enhanced solutions; healthcare delivery restructuring; and economic incentives and social protection interventions. Each category is discussed, including descriptions of interventions, current evidence for effectiveness, and what appears promising for the near future. Approaches to intervention implementation and impact assessment are then described. Results and discussion: The evidence base is promising for currently available, effective, and scalable ART adherence interventions for resource-limited settings. Numerous interventions build on existing health care

  20. Newborn Resuscitation Training in Resource-Limited Settings: A Systematic Literature Review.

    Science.gov (United States)

    Reisman, Jonathan; Arlington, Lauren; Jensen, Lloyd; Louis, Henry; Suarez-Rebling, Daniela; Nelson, Brett D

    2016-08-01

    Birth asphyxia contributes substantially to neonatal mortality in low- and middle-income countries (LMICs). The effects of training birth attendants in neonatal resuscitation (NR) on mortality are limited by falloff of skills and knowledge over time and transference of learned skills into clinical practice. This review examined acquisition and retention of NR knowledge and skills by birth attendants in LMICs and the effectiveness of interventions to improve them. Medline, Cochrane, Embase, CINAHL, Bireme, and African Index Medicus databases were searched. We reviewed Web pages and reports from non-peer-reviewed (or "gray") literature sources addressing NR training in LMICs. Articles on acquisition and retention of NR knowledge and skills, and interventions to improve them, were limited to LMICs. The initial search identified 767 articles, of which 45 met all inclusion criteria. Of these, 31 articles analyzed acquisition of knowledge and skills, and 19 analyzed retention. Most studies found high acquisition rates, although birth attendants struggled to learn bag-mask ventilation. Although significant falloff of knowledge and skills occurred after training, refresher training seemed to improve retention. Results of the gray literature analysis suggest that formal, structured practice sessions improve retention. This review did not analyze training's direct impact on mortality. Knowledge and skills falloff is a significant barrier to the success of NR training programs and possibly to reducing newborn mortality in LMICs. Refresher training and structured practice show significant promise. Additional research is needed to implement and assess retention improvement strategies in classroom and clinical settings. Copyright © 2016 by the American Academy of Pediatrics.

  1. Elevated ability to compete for limited food resources by 'all-fish' growth hormone transgenic common carp Cyprinus carpio.

    Science.gov (United States)

    Duan, M; Zhang, T; Hu, W; Sundström, L F; Wang, Y; Li, Z; Zhu, Z

    2009-10-01

    Food consumption, number of movements and feeding hierarchy of juvenile transgenic common carp Cyprinus carpio and their size-matched non-transgenic conspecifics were measured under conditions of limited food supply. Transgenic fish exhibited 73.3% more movements as well as a higher feeding order, and consumed 1.86 times as many food pellets as their non-transgenic counterparts. After the 10 day experiment, transgenic C. carpio had still not realized their higher growth potential, which may be partly explained by the higher frequency of movements of transgenics and the 'sneaky' feeding strategy used by the non-transgenics. The results indicate that these transgenic fish possess an elevated ability to compete for limited food resources, which could be advantageous after an escape into the wild. It may be that other factors in the natural environment (i.e. predation risk and food distribution), however, would offset this advantage. Thus, these results need to be assessed with caution.

  2. Generic and low dose antiretroviral therapy in adults and children: implication for scaling up treatment in resource limited settings

    Directory of Open Access Journals (Sweden)

    Ramautarsing Reshmie

    2010-06-01

    Full Text Available Abstract Although access to antiretroviral therapy (ART for the treatment of HIV has increased during the last decade, many patients are still in need of treatment. With limited funds to provide ART to millions of patients worldwide, there is a need for alternative ways to scale up ART in resource limited settings. This review provides an overview of pharmacokinetic, safety and efficacy studies of generic and reduced dose ART. The production of generic ART has greatly influenced the decline in drug prices and the increased in ART access. Generic ART has good pharmacokinetic profile, safety and efficacy. Toxicity is however the main cause for ART discontinuation. Several dose reduction studies have shown adequate pharmacokinetic parameters and short term efficacy with reduced dose ART. Ethnicity may affect drug metabolism; several pharmacokinetic studies have confirmed higher plasma ART concentration in Asians. Randomized efficacy trial of reduced versus standard ART is warranted.

  3. Epidemiology, Diagnosis, and Treatment of HIV-Associated Non-Hodgkin Lymphoma in Resource-Limited Settings

    Directory of Open Access Journals (Sweden)

    Matthew Ulrickson

    2012-01-01

    Full Text Available Lymphoma was a common complication of HIV infection in the pre-antiretroviral era, and the incidence of HIV-associated lymphoma has dropped dramatically since the introduction of combination antiretroviral therapy (cART in resource-rich regions. Conversely, lymphoma is an increasingly common complication of HIV infection in resource-limited settings where the prevalence of HIV infection is high. Relatively little is known, however, about the true incidence and optimal treatment regimens for HIV-associated lymphoma in resource-poor regions. We review the epidemiology, diagnosis, and treatment of HIV-associated non-Hodgkin lymphoma in developing nations and highlight areas for further research that may benefit care in both settings. Examples include risk modification and dose modification of chemotherapy based on HIV risk factors, improving our understanding of the current burden of disease through national cancer registries, and developing cost-effective hematopathological diagnostic strategies to optimize care delivery and maximize use of available chemotherapy.

  4. Wind pollination and propagule formation in Rhizophora mangle L. (Rhizophoraceae): resource or pollination limitation?

    Science.gov (United States)

    Nadia, Tarcila L; Machado, Isabel C

    2014-03-01

    Rhizophora mangle is considered as a self-compatible mangrove, and is pollinated by wind and insects. However, there is no information about fruit production by autogamy and agamospermy and on the foraging behavior of its flower visitors. Hence, the present study analyzed the pollination and reproductive systems of R. mangle in a mangrove community in northern Pernambuco, Brazil. Floral morphology, sequence of anthesis, and behavior of flower visitors were described; the proportion of flowers that resulted in mature propagules was also recorded. Autogamy, agamospermy, and wind pollination tests were performed, and a new anemophily index is proposed. The flowers of R. mangle are hermaphrodite, protandric, and have high P/O rate. Flies were observed on flowers only during the male phase, probably feeding on mites that consume pollen. Rhizophora mangle is not agamospermic and its fruit production rate by spontaneous self-pollination is low (2.56%) compared to wind pollination (19.44%). The anemophily index was high 0.98, and thus it was considered as a good indicator. Only 13.79% of the flowers formed mature propagules. The early stages of fruit development are the most critical and susceptible to predation. Rhizophora mangle is, therefore, exclusively anemophilous in the study area and the propagule dispersal seems to be limited by herbivory.

  5. Finishing genomes with limited resources: lessons from an ensemble of microbial genomes

    Directory of Open Access Journals (Sweden)

    Bishop-Lilly Kimberly A

    2010-04-01

    Full Text Available Abstract While new sequencing technologies have ushered in an era where microbial genomes can be easily sequenced, the goal of routinely producing high-quality draft and finished genomes in a cost-effective fashion has still remained elusive. Due to shorter read lengths and limitations in library construction protocols, shotgun sequencing and assembly based on these technologies often results in fragmented assemblies. Correspondingly, while draft assemblies can be obtained in days, finishing can take many months and hence the time and effort can only be justified for high-priority genomes and in large sequencing centers. In this work, we revisit this issue in light of our own experience in producing finished and nearly-finished genomes for a range of microbial species in a small-lab setting. These genomes were finished with surprisingly little investments in terms of time, computational effort and lab work, suggesting that the increased access to sequencing might also eventually lead to a greater proportion of finished genomes from small labs and genomics cores.

  6. The Effects of Resource Limitation on a Predator-Prey Model with Control Measures as Nonlinear Pulses

    Directory of Open Access Journals (Sweden)

    Wenjie Qin

    2014-01-01

    Full Text Available The dynamical behavior of a Holling II predator-prey model with control measures as nonlinear pulses is proposed and analyzed theoretically and numerically to understand how resource limitation affects pest population outbreaks. The threshold conditions for the stability of the pest-free periodic solution are given. Latin hypercube sampling/partial rank correlation coefficients are used to perform sensitivity analysis for the threshold concerning pest extinction to determine the significance of each parameter. Comparing this threshold value with that without resource limitation, our results indicate that it is essential to increase the pesticide’s efficacy against the pest and reduce its effectiveness against the natural enemy, while enhancing the efficiency of the natural enemies. Once the threshold value exceeds a critical level, both pest and its natural enemies populations can oscillate periodically. Further-more, when the pulse period and constant stocking number as a bifurcation parameter, the predator-prey model reveals complex dynamics. In addition, numerical results are presented to illustrate the feasibility of our main results.

  7. International neurocognitive normative study: neurocognitive comparison data in diverse resource-limited settings: AIDS Clinical Trials Group A5271.

    Science.gov (United States)

    Robertson, K; Jiang, H; Evans, S R; Marra, C M; Berzins, B; Hakim, J; Sacktor, N; Silva, M Tulius; Campbell, T B; Nair, A; Schouten, J; Kumwenda, J; Supparatpinyo, K; Tripathy, S; Kumarasamy, N; la Rosa, A; Montano, S; Mwafongo, A; Firnhaber, C; Sanne, I; Naini, L; Amod, F; Walawander, A

    2016-08-01

    Infrastructure for conducting neurological research in resource-limited settings (RLS) is limited. The lack of neurological and neuropsychological (NP) assessment and normative data needed for clinical interpretation impedes research and clinical care. Here, we report on ACTG 5271, which provided neurological training of clinical site personnel and collected neurocognitive normative comparison data in diverse settings. At ten sites in seven RLS countries, we provided training for NP assessments. We collected normative comparison data on HIV- participants from Brazil (n = 240), India (n = 480), Malawi (n = 481), Peru (n = 239), South Africa (480), Thailand (n = 240), and Zimbabwe (n = 240). Participants had a negative HIV test within 30 days before standardized NP exams were administered at baseline and 770 at 6 months. Participants were enrolled in eight strata, gender (female and male), education (normative data needed to build infrastructure for future neurological and neurocognitive studies in diverse RLS. These normative data are a much-needed resource for both clinicians and researchers.

  8. Prolonging life and delaying death: The role of physicians in the context of limited intensive care resources

    Directory of Open Access Journals (Sweden)

    Bagshaw Sean M

    2009-02-01

    Full Text Available Abstract Critical care is in an emerging crisis of conflict between what individuals expect and the economic burden society and government are prepared to provide. The goal of critical care support is to prevent suffering and premature death by intensive therapy of reversible illnesses within a reasonable timeframe. Recently, it has become apparent that early support in an intensive care environment can improve patient outcomes. However, life support technology has advanced, allowing physicians to prolong life (and postpone death in circumstances that were not possible in the recent past. This has been recognized by not only the medical community, but also by society at large. One corollary may be that expectations for recovery from critical illness have also become extremely high. In addition, greater numbers of patients are dying in intensive care units after having receiving prolonged durations of life-sustaining therapy. Herein lies the emerging crisis – critical care therapy must be available in a timely fashion for those who require it urgently, yet its provision is largely dependent on a finite availability of both capital and human resources. Physicians are often placed in a troubling conflict of interest by pressures to use health resources prudently while also promoting the equitable and timely access to critical care therapy. In this commentary, these issues are broadly discussed from the perspective of the individual clinician as well as that of society as a whole. The intent is to generate dialogue on the dynamic between individual clinicians navigating the complexities of how and when to use critical care support in the context of end-of-life issues, the increasing demands placed on finite critical care capacity, and the reasonable expectations of society.

  9. Does Predator Go for Size Selection or Preferential Toxic-Nontoxic Species Under Limited Resource?

    Directory of Open Access Journals (Sweden)

    Joydeep Pal

    2010-01-01

    terminating with a positive growth. To evaluate the bias in the result of experiment we have estimated the variance levels of sample biomasses for each of the experimental time points for each of the three species. Conclusion: The observed stable nature of the zooplankton biomass may be due to initial NTP uptakes but a sudden decline suggests that they are forced to feed on the TPP for survival. In absence of grazing pressure, TPP initially showed a mild positive growth but when the predator switch to TPP for food it shows a negative growth and finally due to rapid mortality of zooplankton and excretal nutrient input the growth rate again kicks up. In summary we conclude that the zooplankter (Artemia salina can discriminate toxic and nontoxic food species and more inclined toward the non-toxic species if the resource available. But shortage of nontoxic species, force them to feed on toxic one, in spite of drastic adverse effect on its survival.

  10. EPA's Safe and Sustainable Water Resources Research Program: Water Systems Research

    Science.gov (United States)

    Water systems challenged by limited resources, aging infrastructure, shifting demographics, climate change, and extreme weather events need transformative approaches to meet public health and environmental goals, while optimizing water treatment and maximizing resource recovery a...

  11. Analysis of Reach-to-Grasp by School-Aged Children with Down Syndrome Elucidates Limitations in Upper Extremity Motor Control.

    Science.gov (United States)

    Valvano, Joanne; Hogy, Sara; Worster, Kate; Ma, Julie; Denniston, Nancy; Winders, Patricia; Rapport, Mary Jane; Pan, Zhaoxing; Carollo, James J

    2017-11-01

    To identify limitations in preparatory planning (PP) and movement execution that constrain performance of reach-to-grasp (RTG) movements in school-aged children with Down syndrome (DS) and examine the effect of chronological age (CA) on performance. Nine children with DS ages 6 to 12 years and nine with typical development (TD) participated in this pilot descriptive study. Three-dimensional kinematic analysis was applied to RTG movements performed in the context of two functional tasks. PP variables focused on the coordination of reach and grasp. Compared to the group with TD, the group with DS demonstrated significant limitations in anticipatory slowing down of hand transport and orientation of the hand in preparation for object contact. There was also relatively late onset of preparatory grip formation in the group with DS. In regard to movement execution, reach trajectories of the group with DS showed significantly greater deviation from the straight path. Correlations of study variables with CA were low and insignificant in both groups. Motor control mechanisms that mediate both PP and execution of the fundamental RTG movement are potential factors limiting upper extremity activity in school-aged children with DS. They should be addressed in future intervention-based research.

  12. On the design of experiments for the study of extreme field limits in the interaction of laser with ultrarelativistic electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S.V., E-mail: svbulanov@gmail.com [Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); Esirkepov, T.Zh.; Hayashi, Y.; Kando, M.; Kiriyama, H.; Koga, J.K.; Kondo, K.; Kotaki, H.; Pirozhkov, A.S. [Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); Bulanov, S.S. [University of California, Berkeley, CA 94720 (United States); Zhidkov, A.G. [Osaka University, Osaka 565-0871 (Japan); Chen, P. [Leung Center for Cosmology and Particle Astrophysics of the National Taiwan University, Taipei 10617, Taiwan (China); Neely, D. [Central Laser Facility, STFC, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Kato, Y. [The Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka 431-1202 (Japan); Narozhny, N.B. [Moscow Engineering Physics Institute (State University), Moscow 115409 (Russian Federation); Korn, G. [Max-Planck-Institut fuer Quantenoptik, Garching 85748 (Germany); ELI Beamline Facility, Institute of Physics, Czech Academy of Sciences, Prague 18221 (Czech Republic)

    2011-12-21

    We propose the experiments on the collision of laser light and high intensity electromagnetic pulses generated by relativistic flying mirrors, with electron bunches produced by a conventional accelerator and with laser wake field accelerated electrons for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The regimes of dominant radiation reaction, which completely changes the electromagnetic wave-matter interaction, will be revealed in the laser plasma experiments. This will result in a new powerful source of ultra short high brightness gamma-ray pulses. A possibility of the demonstration of the electron-positron pair creation in vacuum in a multi-photon processes can be realized. This will allow modeling under terrestrial laboratory conditions neutron star magnetospheres, cosmological gamma ray bursts and the Leptonic Era of the Universe.

  13. On the design of experiments for the study of extreme field limits in the interaction of laser with ultrarelativistic electron beam

    CERN Document Server

    Bulanov, S V; Hayashi, Y; Kando, M; Kiriyama, H; Koga, J K; Kondo, K; Kotaki, H; Pirozhkov, A S; Bulanov, S S; Zhidkov, A G; Chen, P; Neely, D; Kato, Y; Narozhny, N B; Korn, G

    2011-01-01

    We propose the experiments on the collision of laser light and high intensity electromagnetic pulses generated by relativistic flying mirrors, with electron bunches produced by a conventional accelerator and with laser wake field accelerated electrons for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The regimes of dominant radiation reaction, which completely changes the electromagnetic wave-matter interaction, will be revealed in the laser plasma experiments. This will result in a new powerful source of ultra short high brightness gamma-ray pulses. A possibility of the demonstration of the electron-positron pair creation in vacuum in a multi-photon processes can be realized. This will allow modeling under terrestrial laboratory conditions neutron star magnetospheres, cosmological gamma ray bursts and the Leptonic Era of the Universe.

  14. Rocky Worlds Limited to ˜1.8 Earth Radii by Atmospheric Escape during a Star’s Extreme UV Saturation

    Science.gov (United States)

    Lehmer, Owen R.; Catling, David C.

    2017-08-01

    Recent observations and analysis of low-mass (planets only have radii up to 1.5-2 R ⊕. Two general hypotheses exist for the cause of the dichotomy between rocky and gas-enveloped planets (or possible water worlds): either low-mass planets do not necessarily form thick atmospheres of a few wt.%, or the thick atmospheres on these planets easily escape, driven by X-ray and extreme ultraviolet (XUV) emissions from young parent stars. Here, we show that a cutoff between rocky and gas-enveloped planets due to hydrodynamic escape is most likely to occur at a mean radius of 1.76 ± 0.38 (2σ) R ⊕ around Sun-like stars. We examine the limit in rocky planet radii predicted by hydrodynamic escape across a wide range of possible model inputs, using 10,000 parameter combinations drawn randomly from plausible parameter ranges. We find a cutoff between rocky and gas-enveloped planets that agrees with the observed cutoff. The large cross-section available for XUV absorption in the extremely distended primitive atmospheres of low-mass planets results in complete loss of atmospheres during the ˜100 Myr phase of stellar XUV saturation. In contrast, more-massive planets have less-distended atmospheres and less escape, and so retain thick atmospheres through XUV saturation—and then indefinitely as the XUV and escape fluxes drop over time. The agreement between our model and exoplanet data leads us to conclude that hydrodynamic escape plausibly explains the observed upper limit on rocky planet size and few planets (a “valley”, or “radius gap”) in the 1.5-2 R ⊕ range.

  15. Postgraduate and research programmes in Medicine and Public Health in Rwanda: an exciting experience about training of human resources for health in a limited resources country.

    Science.gov (United States)

    Kakoma, Jean Baptiste

    2016-01-01

    The area of Human Resources for Health (HRH) is the most critical challenge for the achievement of health related development goals in countries with limited resources. This is even exacerbated in a post conflict environment like Rwanda. The aim of this commentary is to report and share the genesis and outcomes of an exciting experience about training of qualified health workers in medicine and public health as well as setting - up of a research culture for the last nine years (2006 - 2014) in Rwanda. Many initiatives have been taken and concerned among others training of qualified health workers in medicine and public health. From 2006 to 2014, achievements were as follows: launching and organization of 8 Master of Medicine programmes (anesthesiology, family and community medicine, internal medicine, obstetrics & gynecology, otorhinolaryngology, pediatrics, psychiatry and surgery) and 4 Master programmes in public health (MPH, MSc Epidemiology, MSc Field Epidemiology & Laboratory Management, and Master in Hospital and Healthcare Administration); training to completion of more than 120 specialists in medicine, and 200 MPH, MSc Epidemiology, and MSc Field Epidemiology holders; revival of the Rwanda Medical Journal; organization of graduate research training (MPhil and PhD); 3 Master programmes in the pipeline (Global Health, Health Financing, and Supply Chain Management); partnerships with research institutions of great renown, which contributed to the reinforcement of the institutional research capacity and visibility towards excellence in leadership, accountability, and self sustainability. Even though there is still more to be achieved, the Rwanda experience about postgraduate and research programmes is inspiring through close interactions between main stakeholders. This is a must and could allow Rwanda to become one of the rare examples to other more well-to-do Sub - Saharan countries, should Rwanda carry on doing that.

  16. Evaluation of a Smartphone Decision-Support Tool for Diarrheal Disease Management in a Resource-Limited Setting.

    Science.gov (United States)

    Haque, Farhana; Ball, Robyn L; Khatun, Selina; Ahmed, Mujaddeed; Kache, Saraswati; Chisti, Mohammod Jobayer; Sarker, Shafiqul Alam; Maples, Stace D; Pieri, Dane; Vardhan Korrapati, Teja; Sarnquist, Clea; Federspiel, Nancy; Rahman, Muhammad Waliur; Andrews, Jason R; Rahman, Mahmudur; Nelson, Eric Jorge

    2017-01-01

    The emergence of mobile technology offers new opportunities to improve clinical guideline adherence in resource-limited settings. We conducted a clinical pilot study in rural Bangladesh to evaluate the impact of a smartphone adaptation of the World Health Organization (WHO) diarrheal disease management guidelines, including a modality for age-based weight estimation. Software development was guided by end-user input and evaluated in a resource-limited district and sub-district hospital during the fall 2015 cholera season; both hospitals lacked scales which necessitated weight estimation. The study consisted of a 6 week pre-intervention and 6 week intervention period with a 10-day post-discharge follow-up. Standard of care was maintained throughout the study with the exception that admitting clinicians used the tool during the intervention. Inclusion criteria were patients two months of age and older with uncomplicated diarrheal disease. The primary outcome was adherence to guidelines for prescriptions of intravenous (IV) fluids, antibiotics and zinc. A total of 841 patients were enrolled (325 pre-intervention; 516 intervention). During the intervention, the proportion of prescriptions for IV fluids decreased at the district and sub-district hospitals (both p < 0.001) with risk ratios (RRs) of 0.5 and 0.2, respectively. However, when IV fluids were prescribed, the volume better adhered to recommendations. The proportion of prescriptions for the recommended antibiotic azithromycin increased (p < 0.001 district; p = 0.035 sub-district) with RRs of 6.9 (district) and 1.6 (sub-district) while prescriptions for other antibiotics decreased; zinc adherence increased. Limitations included an absence of a concurrent control group and no independent dehydration assessment during the pre-intervention. Despite limitations, opportunities were identified to improve clinical care, including better assessment, weight estimation, and fluid/ antibiotic selection. These findings

  17. Evaluation of a Smartphone Decision-Support Tool for Diarrheal Disease Management in a Resource-Limited Setting

    Science.gov (United States)

    Khatun, Selina; Ahmed, Mujaddeed; Kache, Saraswati; Chisti, Mohammod Jobayer; Sarker, Shafiqul Alam; Maples, Stace D.; Pieri, Dane; Vardhan Korrapati, Teja; Sarnquist, Clea; Federspiel, Nancy; Rahman, Muhammad Waliur; Andrews, Jason R.; Rahman, Mahmudur; Nelson, Eric Jorge

    2017-01-01

    The emergence of mobile technology offers new opportunities to improve clinical guideline adherence in resource-limited settings. We conducted a clinical pilot study in rural Bangladesh to evaluate the impact of a smartphone adaptation of the World Health Organization (WHO) diarrheal disease management guidelines, including a modality for age-based weight estimation. Software development was guided by end-user input and evaluated in a resource-limited district and sub-district hospital during the fall 2015 cholera season; both hospitals lacked scales which necessitated weight estimation. The study consisted of a 6 week pre-intervention and 6 week intervention period with a 10-day post-discharge follow-up. Standard of care was maintained throughout the study with the exception that admitting clinicians used the tool during the intervention. Inclusion criteria were patients two months of age and older with uncomplicated diarrheal disease. The primary outcome was adherence to guidelines for prescriptions of intravenous (IV) fluids, antibiotics and zinc. A total of 841 patients were enrolled (325 pre-intervention; 516 intervention). During the intervention, the proportion of prescriptions for IV fluids decreased at the district and sub-district hospitals (both p < 0.001) with risk ratios (RRs) of 0.5 and 0.2, respectively. However, when IV fluids were prescribed, the volume better adhered to recommendations. The proportion of prescriptions for the recommended antibiotic azithromycin increased (p < 0.001 district; p = 0.035 sub-district) with RRs of 6.9 (district) and 1.6 (sub-district) while prescriptions for other antibiotics decreased; zinc adherence increased. Limitations included an absence of a concurrent control group and no independent dehydration assessment during the pre-intervention. Despite limitations, opportunities were identified to improve clinical care, including better assessment, weight estimation, and fluid/ antibiotic selection. These findings

  18. International Neurocognitive Normative Study: Neurocognitive Comparison Data in Diverse Resource Limited Settings: AIDS Clinical Trials Group A5271

    Science.gov (United States)

    Robertson, K; Jiang, H; Evans, SR; Marra, CM; Berzins, B; Hakim, J; Sacktor, N; Silva, M Tulius; Campbell, TB; Nair, A; Schouten, J; Kumwenda, J; Supparatpinyo, K; Tripathy, S.; Kumarasamy, N; La Rosa, A; Montano, S; Mwafongo, A; Firnhaber, C; Sanne, I; Naini, L.; Amod, F; Walawander, A

    2016-01-01

    Summary ACTG A5271 collected neurocognitive normative comparison test data in 2400 at-risk HIV seronegative participants from Brazil, India, Malawi, Peru, South Africa, Thailand and Zimbabwe. The participants were enrolled in strata by site (10 levels), age (2 levels), education (2 levels), and gender (2 levels). These data provide necessary normative data infrastructure for future clinical research and care in these diverse resource limited settings. Infrastructure for conducting neurological research in resource limited settings (RLS) is limited. The lack of neurological and neuropsychological (NP) assessment, and normative data needed for clinical interpretation impede research and clinical care. Here we report on ACTG 5271, which provided neurological training of clinical site personnel, and collected neurocognitive normative comparison data in diverse settings. At 10 sites in seven RLS countries, we provided training for NP assessments. We collected normative comparison data on HIV- participants from Brazil (n=240), India (n=480), Malawi (n=481), Peru (n=239), South Africa (480), Thailand (n=240) and Zimbabwe (n=240). Participants had a negative HIV test within 30 days before standardized NP exams were administered at baseline, and 770 at six-months. Participants were enrolled in 8 strata, gender (female and male), education (<10 years and ≥ 10 years), and age (<35 years and ≥35 years). Of 2400 enrolled, 770 completed the six-month follow up. As expected, significant between-country differences were evident in all the neurocognitive test scores (p<.0001). There was variation between the age, gender and education strata on the neurocognitive tests. Age and education were important variables for all tests; older participants had poorer performance and those with higher education had better performance. Women had better performance on verbal learning/memory and speed of processing tests, while men performed better on motor tests. This study provides the

  19. Equity of access to reproductive health services among youths in resource-limited suburban communities of Mandalay City, Myanmar.

    Science.gov (United States)

    Thin Zaw, Phyu Phyu; Liabsuetrakul, Tippawan; Htay, Thien Thien; McNeil, Edward

    2012-12-15

    Inequity of accessibility to and utilization of reproductive health (RH) services among youths is a global concern, especially in resource-limited areas. The level of inequity also varies by cultural and socio-economic contexts. To tailor RH services to the needs of youths, relevant solutions are required. This study aimed to assess baseline information on access to and utilization of RH services and unmet needs among youths living in resource-limited, suburban communities of Mandalay City, Myanmar. A community-based, cross-sectional study was conducted in all resource-limited, suburban communities of Mandalay City, Myanmar. A total of 444 randomly selected youths aged between 15 and 24 years were interviewed for three main outcomes, namely accessibility to and utilization of RH services and youth's unmet needs for these services. Factors associated with these outcomes were determined using multivariate logistic regression. Although geographical accessibility was high (79.3%), financial accessibility was low (19.1%) resulting in a low overall accessibility (34.5%) to RH services. Two-thirds of youths used some kind of RH services at least once in the past. Levels of unmet needs for sexual RH information, family planning, maternal care and HIV testing were 62.6%, 31.9%, 38.7% and 56.2%, respectively. Youths living in the south or south-western suburbs, having a deceased parent, never being married or never exposed to mass media were less likely to access RH services. Being a young adult, current student, working as a waste recycler, having ever experienced a sexual relationship, ever being married, ever exposed to mass media, having a high knowledge of RH services and providers or a high level of accessibility to RH services significantly increased the likelihood of utilization of those services. In addition to youths' socio-demographic characteristics, exposure to mass media, norm of peer exposure and knowledge on types of providers and services significantly

  20. Equity of access to reproductive health services among youths in resource-limited suburban communities of Mandalay City, Myanmar

    Directory of Open Access Journals (Sweden)

    Thin Zaw Phyu Phyu

    2012-12-01

    Full Text Available Abstract Background Inequity of accessibility to and utilization of reproductive health (RH services among youths is a global concern, especially in resource-limited areas. The level of inequity also varies by cultural and socio-economic contexts. To tailor RH services to the needs of youths, relevant solutions are required. This study aimed to assess baseline information on access to and utilization of RH services and unmet needs among youths living in resource-limited, suburban communities of Mandalay City, Myanmar. Methods A community-based, cross-sectional study was conducted in all resource-limited, suburban communities of Mandalay City, Myanmar. A total of 444 randomly selected youths aged between 15 and 24 years were interviewed for three main outcomes, namely accessibility to and utilization of RH services and youth's unmet needs for these services. Factors associated with these outcomes were determined using multivariate logistic regression. Results Although geographical accessibility was high (79.3%, financial accessibility was low (19.1% resulting in a low overall accessibility (34.5% to RH services. Two-thirds of youths used some kind of RH services at least once in the past. Levels of unmet needs for sexual RH information, family planning, maternal care and HIV testing were 62.6%, 31.9%, 38.7% and 56.2%, respectively. Youths living in the south or south-western suburbs, having a deceased parent, never being married or never exposed to mass media were less likely to access RH services. Being a young adult, current student, working as a waste recycler, having ever experienced a sexual relationship, ever being married, ever exposed to mass media, having a high knowledge of RH services and providers or a high level of accessibility to RH services significantly increased the likelihood of utilization of those services. In addition to youths’ socio-demographic characteristics, exposure to mass media, norm of peer exposure and knowledge

  1. How extreme are extremes?

    Science.gov (United States)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  2. Maximizing the benefit of health workforce secondment in Botswana: an approach for strengthening health systems in resource-limited settings.

    Science.gov (United States)

    Grignon, Jessica S; Ledikwe, Jenny H; Makati, Ditsapelo; Nyangah, Robert; Sento, Baraedi W; Semo, Bazghina-Werq

    2014-01-01

    To address health systems challenges in limited-resource settings, global health initiatives, particularly the President's Emergency Plan for AIDS Relief, have seconded health workers to the public sector. Implementation considerations for secondment as a health workforce development strategy are not well documented. The purpose of this article is to present outcomes, best practices, and lessons learned from a President's Emergency Plan for AIDS Relief-funded secondment program in Botswana. Outcomes are documented across four World Health Organization health systems' building blocks. Best practices include documentation of joint stakeholder expectations, collaborative recruitment, and early identification of counterparts. Lessons learned include inadequate ownership, a two-tier employment system, and ill-defined position duration. These findings can inform program and policy development to maximize the benefit of health workforce secondment. Secondment requires substantial investment, and emphasis should be placed on high-level technical positions responsible for building systems, developing health workers, and strengthening government to translate policy into programs.

  3. Human olfactory consciousness and cognition: its unusual features may not result from unusual functions but from limited neocortical processing resources

    Science.gov (United States)

    Stevenson, Richard J.; Attuquayefio, Tuki

    2013-01-01

    Human and animal olfactory perception is shaped both by functional demands and by various environmental constraints seemingly peculiar to chemical stimuli. These demands and constraints may have generated a sensory system that is cognitively distinct from the major senses. In this article we identify these various functional demands and constraints, and examine whether they can be used to account for olfaction's unique cognitive features on a case-by-case basis. We then use this as grounds to argue that specific conscious processes do have functional value, a finding that naturally emerges when a comparative approach to consciousness across the senses is adopted. More generally, we conclude that certain peculiar features of olfactory cognition may owe more to limited neocortical processing resources, than they do to the challenges faced by perceiving chemical stimuli. PMID:24198808

  4. A Subgrid Parameterization for Wind Turbines in Weather Prediction Models with an Application to Wind Resource Limits

    Directory of Open Access Journals (Sweden)

    B. H. Fiedler

    2014-01-01

    Full Text Available A subgrid parameterization is offered for representing wind turbines in weather prediction models. The parameterization models the drag and mixing the turbines cause in the atmosphere, as well as the electrical power production the wind causes in the wind turbines. The documentation of the parameterization is complete; it does not require knowledge of proprietary data of wind turbine characteristics. The parameterization is applied to a study of wind resource limits in a hypothetical giant wind farm. The simulated production density was found not to exceed 1 W m−2, peaking at a deployed capacity density of 5 W m−2 and decreasing slightly as capacity density increased to 20 W m−2.

  5. Best practices in developing a national palliative care policy in resource limited settings: lessons from five African countries.

    Science.gov (United States)

    Luyirika, Emmanuel Bk; Namisango, Eve; Garanganga, Eunice; Monjane, Lidia; Ginindza, Ntombi; Madonsela, Gugulethu; Kiyange, Fatia

    2016-01-01

    Given the high unmet need for palliative care in Africa and other resource limited settings, it is important that countries embrace the public health approach to increasing access through its integration within existing healthcare systems. To give this approach a strong foundation that would ensure sustainability, the World Health Organisation urges member states to ensure that policy environments are suitable for this intervention. The development, strengthening, and implementation of national palliative care policies is a priority. Given the lack of a critical mass of palliative care professionals in the region and deficiency in documenting and sharing best practices as part of information critical for regional development, policy development becomes a complex process. This article shares experiences with regard to best practices when advocating the national palliative care policies. It also tells about policy development process, the important considerations, and cites examples of policy content outlines in Africa.

  6. Maximizing the benefit of health workforce secondment in Botswana: an approach for strengthening health systems in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Grignon JS

    2014-05-01

    Full Text Available Jessica S Grignon,1,2 Jenny H Ledikwe,1,2 Ditsapelo Makati,2 Robert Nyangah,2 Baraedi W Sento,2 Bazghina-werq Semo1,2 1Department of Global Health, University of Washington, Seattle, WA, USA; 2International Training and Education Center for Health, Gaborone, Botswana Abstract: To address health systems challenges in limited-resource settings, global health initiatives, particularly the President's Emergency Plan for AIDS Relief, have seconded health workers to the public sector. Implementation considerations for secondment as a health workforce development strategy are not well documented. The purpose of this article is to present outcomes, best practices, and lessons learned from a President's Emergency Plan for AIDS Relief-funded secondment program in Botswana. Outcomes are documented across four World Health Organization health systems' building blocks. Best practices include documentation of joint stakeholder expectations, collaborative recruitment, and early identification of counterparts. Lessons learned include inadequate ownership, a two-tier employment system, and ill-defined position duration. These findings can inform program and policy development to maximize the benefit of health workforce secondment. Secondment requires substantial investment, and emphasis should be placed on high-level technical positions responsible for building systems, developing health workers, and strengthening government to translate policy into programs. Keywords: human resources, health policy, health worker, HIV/AIDS, PEPFAR

  7. Patterns of fruit and seed set within inflorescences of Pancratium maritimum (Amaryllidaceae): nonuniform pollination, resource limitation, or architectural effects?

    Science.gov (United States)

    Medrano, M; Guitián, P; Guitián, J

    2000-04-01

    We investigated patterns of fruit and seed production on inflorescences of a population of Pancratium maritimum in northwest Spain over a 2-yr period. Initial findings showed that the earliest opening flowers on an inflorescence are more likely to set fruit and produce more seeds than later opening flowers and that this pattern is maintained throughout the flowering season. Supplementary pollination and flower-removal experiments were performed to investigate whether the observed pattern is attributable (a) to variation in pollen receipt, (b) to sequestration of resources by the earliest flowers on an inflorescence, and/or (c) to "architectural" limitations on the fruit/seed production of later flowers. Supplementary pollination did not improve fruit or seed production by late flowers in either of the 2 yr of study. In flower-removal experiments, the remaining flowers showed improved fruit set and mean number of seeds per flower, by comparison with flowers in the same position on control inflorescences. When all flowers except the latest third were removed, these showed fruit set and seed production similar to those of early flowers on control inflorescences. These results strongly suggest that the observed within-inflorescence patterns of fruit and seed production in P. maritimum are mainly attributable to competition for resources (i.e., explanation b), though other adaptive explanations cannot be ruled out.

  8. Quality assessment of an interferon-gamma release assay for tuberculosis infection in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    Hang Nguyen TL

    2009-05-01

    Full Text Available Abstract Background When a test for diagnosis of infectious diseases is introduced in a resource-limited setting, monitoring quality is a major concern. An optimized design of experiment and statistical models are required for this assessment. Methods Interferon-gamma release assay to detect tuberculosis (TB infection from whole blood was tested in Hanoi, Viet Nam. Balanced incomplete block design (BIBD was planned and fixed-effect models with heterogeneous error variance were used for analysis. In the first trial, the whole blood from 12 donors was incubated with nil, TB-specific antigens or mitogen. In 72 measurements, two laboratory members exchanged their roles in harvesting plasma and testing for interferon-gamma release using enzyme linked immunosorbent assay (ELISA technique. After intervention including checkup of all steps and standard operation procedures, the second trial was implemented in a similar manner. Results The lack of precision in the first trial was clearly demonstrated. Large within-individual error was significantly affected by both harvester and ELISA operator, indicating that both of the steps had problems. After the intervention, overall within-individual error was significantly reduced (P Conclusion BIBD and analysis of fixed-effect models with heterogeneous variance are suitable and useful for objective and individualized assessment of proficiency in a multistep diagnostic test for infectious diseases in a resource-constrained laboratory. The action plan based on our findings would be worth considering when monitoring for internal quality control is difficult on site.

  9. Situações limite decorrentes da violência de gênero Situações limite decorrentes da violência de gênero Extreme situations due to gender violence

    Directory of Open Access Journals (Sweden)

    Stela Meneghel

    2012-11-01

    Full Text Available

    Este texto apresenta uma síntese do Seminário Rotas Críticas III, realizado em Porto Alegre/Brasil, em 2011, cujo foco foi situações limite da violência de gênero. As situações limite são violações de direitos humanos que incluem os femicídios ou assassinatos motivados pela situação de gênero; assassinatos de pessoas LGBT, violações a direitos de minorias étnicas e raciais, exploração sexual, violências a mulheres em situação de vulnerabilidade e outras violências decorrentes de gênero. O objetivo do encontro foi oportunizar espaço para partilhar experiências, refletir criticamente e construir estratégias para o enfrentamento de violências e situações limite decorrentes de sistemas de gênero.

     

    Este texto apresenta uma síntese do Seminário Rotas Críticas III, realizado em Porto Alegre/Brasil, em 2011, cujo foco foi situações limite da violência de gênero. As situações limite são violações de direitos humanos que incluem os femicídios ou assassinatos motivados pela situação de gênero; assassinatos de pessoas LGBT, violações a direitos de minorias étnicas e raciais, exploração sexual, violências a mulheres em situação de vulnerabilidade e outras violências decorrentes de gênero. O objetivo do encontro foi oportunizar espaço para partilhar experiências, refletir criticamente e construir estratégias para o enfrentamento de violências e situações limite decorrentes de sistemas de gênero.

    This paper presents a synthesis of the third Critical Paths Seminar, held in Porto Alegre/Brazil in 2011, whose focus was extreme situations of gender violence. The extreme situations are human rights violations that include femicide or murder motivated by the situation of gender; LGBT murders, human rights violations of ethnic and racial minorities, sexual exploitation, violence to women in vulnerable situations

  10. Dry Blood Spots a Reliable Method for Measurement of Hepatitis B Viral Load in Resource-Limited Settings

    Science.gov (United States)

    Stene-Johansen, Kathrine; Yaqoob, Nadeem; Overbo, Joakim; Aberra, Hanna; Desalegn, Hailemichael; Berhe, Nega; Johannessen, Asgeir

    2016-01-01

    Background & Aims Hepatitis B virus (HBV) quantification is essential in the management of chronic hepatitis B, both to determine treatment eligibility and in the monitoring of treatment effect. This test, however, is rarely available in resource-limited settings due to high costs and stringent requirements for shipment and storage of plasma. Dried Blood Spots (DBS) can be a convenient alternative to plasma, but its use for HBV monitoring has not been investigated under real-life conditions in Africa. Methods The performance of DBS in HBV quantification was investigated using a modified commercial test (Abbott RealTime HBV assay). Paired DBS and plasma samples were collected from an HBV positive cohort in Addis Ababa, Ethiopia. DBS were stored at ambient temperature for 4–39 days before shipment to the laboratory. Results Twenty-six paired samples were selected covering the total range of quantification, from 2.14 log IU/ml to >7 log IU/ml. HBV was detected in 21 of 21 (100%) DBS from patients with a corresponding plasma viral load above 2.70 log IU/ml. The mean difference between plasma and DBS was 0.59 log IU/ml, and the correlation was strong (R2 = 0.92). In stability studies there was no significant change in DBS viral load after storage at room temperature for up to 12 weeks. Conclusions This study suggests that DBS can be a feasible and reliable alternative to plasma for quantification of HBV in resource-limited settings. DBS can expand access to antiviral treatment for patients in low- and middle-income countries. PMID:27820845

  11. Offering an American graduate medical HIV course to health care workers in resource-limited settings via the Internet.

    Science.gov (United States)

    Chung, Michael H; Severynen, Anneleen O; Hals, Matthew P; Harrington, Robert D; Spach, David H; Kim, H Nina

    2012-01-01

    Western accredited medical universities can offer graduate-level academic courses to health care workers (HCWs) in resource-limited settings through the Internet. It is not known whether HCWs are interested in these online courses, whether they can perform as well as matriculated students, or whether such courses are educationally or practically relevant. In 2011, the University of Washington (UW) Schools of Medicine and Nursing offered the graduate course, "Clinical Management of HIV", to HCWs that included a demographic survey, knowledge assessment, and course evaluation. UW faculty delivered HIV clinical topics through ten 2-hour weekly sessions from the perspectives of practicing HIV medicine in developed and developing settings. HCWs viewed lectures through Adobe Acrobat Connect Pro (Adobe Systems, San Jose, CA), and completed online homework on HIV Web Study (http://depts.washington.edu/hivaids/) and online quizzes. HCWs, who met the same passing requirements as UW students by attending 80% lectures, completing ≥90% homework, and achieving a cumulative ≥70% grade on quizzes, were awarded a certificate. 369 HCWs at 33 sites in 21 countries joined the course in 2011, a >15-fold increase since the course was first offered in 2007. The majority of HCWs came from Africa (72%), and most were physicians (41%), nurses (22%), or midlevel practitioners (20%). 298 HCWs (81%) passed all requirements and earned a certificate. In a paired analysis of pre- and post-course HIV knowledge assessments, 56% of HCWs improved their post-course score (p<0.0001) with 27% improving by at least 30%. In the course evaluation, most HCWs rated the course as excellent (53%) or very good (39%). This online HIV course demonstrated that opening a Western graduate medical and nursing curriculum to HCWs in resource-limited settings is feasible, popular, and valuable, and may address logistic and economic barriers to the provision of high quality education in these settings.

  12. e-Assessment in a Limited-Resources Dental School Using an Open-Source Learning Management System.

    Science.gov (United States)

    El Tantawi, Maha M A; Abdelsalam, Maha M; Mourady, Ahmed M; Elrifae, Ismail M B

    2015-05-01

    e-Assessment provides solutions to some problems encountered in dental students' evaluation. The aim of this study was to evaluate the experience of a limited-resources dental school with e-assessment provided through an open-source learning management system (LMS). Data about users' access and types of e-assessment activities at the Faculty of Dentistry, Alexandria University, Egypt, were obtained from the web-based LMS Moodle. A questionnaire developed to assess students' perceptions of the e-assessment was also sent to students registered in two courses (undergraduate and postgraduate) with the same instructor. The results showed that most e-courses at the school had one form of e-assessment (82%) and, of these, 16.7% had summative assessment activities. There were significant differences among departments in the number of e-courses with e-assessment. One-quarter of e-courses with e-assessment used Moodle quizzes. Of 285 students registered in the two courses that included the questionnaire, 170 responded (response rate=59.6%). The responding students positively perceived the impact of e-assessment on learning and its reliability and security, whereas technical issues and related stresses were negatively perceived. This study suggests that e-assessment can be used at minimal cost in dental schools with limited resources and large class sizes with the least demands on faculty members and teaching staff time. For these schools, an open-source LMS such as Moodle provides formative e-assessment not available otherwise and accommodates various question formats and varying levels of instructors' technical skills. These students seemed to have a positive impression of the e-assessment although technical problems and related stresses are issues that need to be addressed.

  13. The influence of gender on conflicts of interest in the allocation of limited critical care resources: justice versus care.

    Science.gov (United States)

    Self, D J; Olivarez, M

    1993-03-01

    After noting that the principle of autonomy has been inadequate for the resolution of many of the complex and difficult moral dilemmas involving conflicts of interest in the allocation of limited critical care resources, this paper analyzes the concepts of justice and care as alternative solutions to moral problems and applies them to the issue of repeat organ transplants to a single recipient. These concepts are found to be the basis of the notions of moral reasoning and moral orientation, respectively, which serve in moral development theory as two fundamentally different ways to approach moral problem solving. Following an elaboration of moral reasoning as found in Kohlberg's cognitive moral development theory, the influence of gender on moral reasoning is investigated. The empirical data show that women (mean Defining Issues Test score, 47.18) score significantly higher (P moral reasoning based on the concept of justice for resolving moral dilemmas. Following an elaboration of moral orientation as found in Gilligan's moral theory of the ethics of care, the influence of gender on moral orientation is investigated. The empirical data show that women use the concept of care significantly more often (P moral dilemmas. From these data it is concluded that men are more likely than women to use justice in the resolution of moral dilemmas, such as the conflicts of interest in the allocation of limited critical care resources, but that if women do use, or are required by the social system to use, justice in the resolution of moral dilemmas, they do a better job of it than men.

  14. Evaluating the Auto-MODS assay, a novel tool for tuberculosis diagnosis for use in resource-limited settings.

    Science.gov (United States)

    Wang, Linwei; Mohammad, Sohaib H; Chaiyasirinroje, Boonchai; Li, Qiaozhi; Rienthong, Somsak; Rienthong, Dhanida; Nedsuwan, Supalert; Mahasirimongkol, Surakameth; Yasui, Yutaka

    2015-01-01

    There is an urgent need for simple, rapid, and affordable diagnostic tests for tuberculosis (TB) to combat the great burden of the disease in developing countries. The microscopic observation drug susceptibility assay (MODS) is a promising tool to fill this need, but it is not widely used due to concerns regarding its biosafety and efficiency. This study evaluated the automated MODS (Auto-MODS), which operates on principles similar to those of MODS but with several key modifications, making it an appealing alternative to MODS in resource-limited settings. In the operational setting of Chiang Rai, Thailand, we compared the performance of Auto-MODS with the gold standard liquid culture method in Thailand, mycobacterial growth indicator tube (MGIT) 960 plus the SD Bioline TB Ag MPT64 test, in terms of accuracy and efficiency in differentiating TB and non-TB samples as well as distinguishing TB and multidrug-resistant (MDR) TB samples. Sputum samples from clinically diagnosed TB and non-TB subjects across 17 hospitals in Chiang Rai were consecutively collected from May 2011 to September 2012. A total of 360 samples were available for evaluation, of which 221 (61.4%) were positive and 139 (38.6%) were negative for mycobacterial cultures according to MGIT 960. Of the 221 true-positive samples, Auto-MODS identified 212 as positive and 9 as negative (sensitivity, 95.9%; 95% confidence interval [CI], 92.4% to 98.1%). Of the 139 true-negative samples, Auto-MODS identified 135 as negative and 4 as positive (specificity, 97.1%; 95% CI, 92.8% to 99.2%). The median time to culture positivity was 10 days, with an interquartile range of 8 to 13 days for Auto-MODS. Auto-MODS is an effective and cost-sensitive alternative diagnostic tool for TB diagnosis in resource-limited settings. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Postoperative Central Nervous System Infection After Neurosurgery in a Modernized, Resource-Limited Tertiary Neurosurgical Center in South Asia.

    Science.gov (United States)

    Chidambaram, Swathi; Nair, M Nathan; Krishnan, Shyam Sundar; Cai, Ling; Gu, Weiling; Vasudevan, Madabushi Chakravarthy

    2015-12-01

    Postoperative central nervous system infections (PCNSIs) are rare but serious complications after neurosurgery. The purpose of this study was to examine the prevalence and causative pathogens of PCNSIs at a modernized, resource-limited neurosurgical center in South Asia. A retrospective analysis was conducted of the medical records of all 363 neurosurgical cases performed between June 1, 2012, and June 30, 2013, at a neurosurgical center in South Asia. Data from all operative neurosurgical cases during the 13-month period were included. Cerebrospinal fluid (CSF) analysis indicated that 71 of the 363 surgical cases had low CSF glucose or CSF leukocytosis. These 71 cases were categorized as PCNSIs. The PCNSIs with positive CSF cultures (9.86%) all had gram-negative bacteria with Pseudomonas aeruginosa (n = 5), Escherichia coli (n = 1), or Klebsiella pneumoniae (n = 1). The data suggest a higher rate of death (P = 0.031), a higher rate of CSF leak (P < 0.001), and a higher rate of cranial procedures (P < 0.001) among the infected patients and a higher rate of CSF leak among the patients with culture-positive infections (P = 0.038). This study summarizes the prevalence, causative organism of PCNSI, and antibiotic usage for all of the neurosurgical cases over a 13-month period in a modernized yet resource-limited neurosurgical center located in South Asia. The results from this study highlight the PCNSI landscape in an area of the world that is often underreported in the neurosurgical literature because of the paucity of clinical neurosurgical research undertaken there. This study shows an increasing prevalence of gram-negative organisms in CSF cultures from PCNSIs, which supports a trend in the recent literature of increasing gram-negative bacillary meningitis. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Potential for Zika virus introduction and transmission in resource limited countries in Africa and Asia-Pacific: A modeling study

    Science.gov (United States)

    German, Matthew; Creatore, Maria I.; Brent, Shannon; Watts, Alexander G.; Hay, Simon I.; Kulkarni, Manisha A.; Brownstein, John S.; Khan, Kamran

    2016-01-01

    Summary Background As the epidemic of Zika virus expands in the Americas, countries across Africa and the Asia-Pacific region are becoming increasingly susceptible to the importation and possible local spread of the virus. To support public health readiness, we aim to identify regions and times where the potential health, economic, and social effects from Zika virus are greatest, focusing on resource-limited countries in Africa and the Asia-Pacific region. Methods Our model combined transportation network analysis, ecological modelling of mosquito occurrences, and vector competence for flavivirus transmission, using data from the International Air Transport Association, entomological observations from Zika’s primary vector species, and climate conditions using WorldClim. We overlaid monthly flows of airline travellers arriving to Africa and the Asia-Pacific region from areas of the Americas suitable for year-round transmission of Zika virus with monthly maps of climatic suitability for mosquito-borne transmission of Zika virus within Africa and the Asia-Pacific region. Findings An estimated 2·6 billion people live in areas of Africa and the Asia-Pacific region where the presence of competent mosquito vectors and suitable climatic conditions could support local transmission of Zika virus. Countries with large volumes of travellers arriving from Zika affected areas of the Americas and large populations at risk of mosquito-borne Zika virus infection include, India (67 422 travellers arriving per year; 1·2 billion residents in potential Zika transmission areas), China (238 415 travellers; 242 million residents), Indonesia (13 865 travellers; 197 million residents), Philippines (35 635 travellers; 70 million residents), and Thailand (29 241 travellers; 59 million residents). Interpretation Many countries across Africa and the Asia-Pacific region are vulnerable to Zika virus. Strategic use of available health and human resources is essential to prevent or mitigate

  17. Resource Limitations Influence Growth and Vigor of Idaho Fescue, a Common Understory Species in Pacific Northwest Ponderosa Pine Forests

    Directory of Open Access Journals (Sweden)

    Craig A. Carr

    2016-12-01

    Full Text Available Alterations in under-canopy resource availability associated with elevated ponderosa pine (Pinus ponderosa Dougl. abundance can negatively influence understory vegetation. Experimental evidence linking under-canopy resource availability and understory vegetation is scarce. Yet this information would be beneficial in developing management strategies to recover desired understory species. We tested the effects of varying nitrogen (N and light availability on Idaho fescue (Festuca idahoensis Elmer, the dominant understory species in ponderosa pine/Idaho fescue plant associations in eastern Oregon. In a greenhouse experiment, two levels of N (50 kg∙N∙ha−1 and 0 kg∙N∙ha−1 and shade (80% shade and 0% shade were applied in a split-plot design to individual potted plants grown in soil collected from high abundance pine stands. Plants grown in unshaded conditions produced greater root (p = 0.0027 and shoot (p = 0.0017 biomass and higher cover values (p = 0.0378 compared to those in the shaded treatments. The addition of N had little effect on plant growth (p = 0.1602, 0.5129, and 0.0853 for shoot biomass, root biomass, and cover, respectively, suggesting that soils in high-density ponderosa pine stands that lack understory vegetation were not N deficient and Idaho fescue plants grown in these soils were not N limited. Management activities that increase under-canopy light availability will promote the conditions necessary for Idaho fescue recovery. However, successful restoration may be constrained by a lack of residual fescue or the invasion of more competitive understory vegetation.

  18. Detection of bone metastasis in nasopharyngeal carcinoma by bone scintigraphy: A retrospective study in perspective of limited resource settings

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    Akhil Kapoor

    2015-01-01

    Full Text Available Background: Nasopharyngeal carcinoma (NPC is an aggressive tumor with a significant proportion of patients presenting with distant metastasis. The skeleton is one of the most common sites of distant failure. This retrospective study was performed to analyze the incidence and patterns of skeletal metastasis in NPC detected by bone scintigraphy in resource-poor settings. Materials and Methods: We analyzed records of 301 NPC patients attending our oncology outpatient department from January 2002 to December 2012. Of these, 33 patients who presented with bony pain underwent bone scan (BS for suspect of skeletal metastasis. In patients with positive scans, histological diagnosis to confirm metastasis was attempted. Results: Bone metastasis (BM was found in 19 patients (57.6% of patients undergoing BS, 6.3% of total NPC patients. About 36.8% and 15.8% of BM cases were in the age group 20-29 and 30-39 years, respectively (P = 0.27. 63.1% of metastatic cases were of World Health Organization type-II histology (P = 0.021. Of the patients diagnosed with BM, 52.6% belonged to stage IV at presentation (P = 0.022. Spine was involved in 56% of the positive cases, followed by the pelvis (32%, and ribs (24%. On univariate analysis, histology (P < 0.001, stage at diagnosis (P = 0.007 and age group (P = 0.001 were identified as significant factors affecting BM. However, on multivariate analysis, only stage (P = 0.001 was a significant factor. Conclusion: Bone scintigraphy can be considered in limited resource settings for the evaluation of distant metastasis in the patients of advanced NPC.

  19. Protein expression and genetic structure of the coral Porites lobata in an environmentally extreme Samoan back reef: Does host genotype limit phenotypic plasticity?

    Science.gov (United States)

    Barshis, D.J.; Stillman, J.H.; Gates, R.D.; Toonen, R.J.; Smith, L.W.; Birkeland, C.

    2010-01-01

    The degree to which coral reef ecosystems will be impacted by global climate change depends on regional and local differences in corals' susceptibility and resilience to environmental stressors. Here, we present data from a reciprocal transplant experiment using the common reef building coral Porites lobata between a highly fluctuating back reef environment that reaches stressful daily extremes, and a more stable, neighbouring forereef. Protein biomarker analyses assessing physiological contributions to stress resistance showed evidence for both fixed and environmental influence on biomarker response. Fixed influences were strongest for ubiquitin-conjugated proteins with consistently higher levels found in back reef source colonies both pre and post-transplant when compared with their forereef conspecifics. Additionally, genetic comparisons of back reef and forereef populations revealed significant population structure of both the nuclear ribosomal and mitochondrial genomes of the coral host (FST = 0.146 P < 0.0001, FST = 0.335 P < 0.0001 for rDNA and mtDNA, respectively), whereas algal endosymbiont populations were genetically indistinguishable between the two sites. We propose that the genotype of the coral host may drive limitations to the physiological responses of these corals when faced with new environmental conditions. This result is important in understanding genotypic and environmental interactions in the coral algal symbiosis and how corals may respond to future environmental changes. ?? 2010 Blackwell Publishing Ltd.

  20. "Pushing the Limits": Rethinking Motor and Cognitive Resources After a Highly Challenging Balance Training Program for Parkinson Disease.

    Science.gov (United States)

    Leavy, Breiffni; Roaldsen, Kirsti Skavberg; Nylund, Kamilla; Hagströmer, Maria; Franzén, Erika

    2016-08-11

    There is growing evidence for the positive effects of exercise training programs on balance control in Parkinson disease (PD). To be effective, balance training needs to be specific, progressive, and highly challenging. Little evidence exists, however, for how people with PD-related balance impairments perceive highly challenging and progressive balance training programs with dual-task components. The purpose of this study was to explore and describe perceptions of a highly challenging balance training program among people with mild to moderate PD. This study was qualitative in nature. In-depth interviews were conducted with 13 individuals with mild to moderate PD who had participated in a highly challenging balance training program. Interview transcripts were analyzed using qualitative content analysis, with an inductive approach. The analysis revealed 3 subthemes concerning participants' perceptions of highly challenging and progressive balance training: (1) movement to counter the disease, (2) dual-task training in contrast to everyday strategies, and (3) the struggle to maintain positive effects. The first subtheme reflects how physical activity was used as a short-term and long-term strategy for counteracting PD symptoms and their progression. The second subtheme incorporates the described experiences of being maximally challenged in a secure and supportive group environment, circumstances that stood in contrast to participants' everyday lives. The third subtheme describes participants' long-term struggle to maintain program effects on cognitive and physical function in the face of disease progression. Interpretation of the underlying patterns of these subthemes resulted in one overarching theme: training at the limits of balance capacity causes a rethinking motor and cognitive resources. The findings of this study cannot be considered to reflect the beliefs of those with weaker or negative beliefs concerning physical activity or be transferred to those at

  1. Allometric Scaling and Resource Limitations Model of Tree Heights: Part 3. Model Optimization and Testing over Continental China

    Directory of Open Access Journals (Sweden)

    Xiliang Ni

    2014-04-01

    Full Text Available The ultimate goal of our multi-article series is to demonstrate the Allometric Scaling and Resource Limitation (ASRL approach for mapping tree heights and biomass. This third article tests the feasibility of the optimized ASRL model over China at both site (14 meteorological stations and continental scales. Tree heights from the Geoscience Laser Altimeter System (GLAS waveform data are used for the model optimizations. Three selected ASRL parameters (area of single leaf, α; exponent for canopy radius, η; and root absorption efficiency, γ are iteratively adjusted to minimize differences between the references and predicted tree heights. Key climatic variables (e.g., temperature, precipitation, and solar radiation are needed for the model simulations. We also exploit the independent GLAS and in situ tree heights to examine the model performance. The predicted tree heights at the site scale are evaluated against the GLAS tree heights using a two-fold cross validation (RMSE = 1.72 m; R2 = 0.97 and bootstrapping (RMSE = 4.39 m; R2 = 0.81. The modeled tree heights at the continental scale (1 km spatial resolution are compared to both GLAS (RMSE = 6.63 m; R2 = 0.63 and in situ (RMSE = 6.70 m; R2 = 0.52 measurements. Further, inter-comparisons against the existing satellite-based forest height maps have resulted in a moderate degree of agreements. Our results show that the optimized ASRL model is capable of satisfactorily retrieving tree heights over continental China at both scales. Subsequent studies will focus on the estimation of woody biomass after alleviating the discussed limitations.

  2. Accuracy of Inferior Vena Cava Ultrasound for Predicting Dehydration in Children with Acute Diarrhea in Resource-Limited Settings.

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    Payal Modi

    Full Text Available Although dehydration from diarrhea is a leading cause of morbidity and mortality in children under five, existing methods of assessing dehydration status in children have limited accuracy.To assess the accuracy of point-of-care ultrasound measurement of the aorta-to-IVC ratio as a predictor of dehydration in children.A prospective cohort study of children under five years with acute diarrhea was conducted in the rehydration unit of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b. Ultrasound measurements of aorta-to-IVC ratio and dehydrated weight were obtained on patient arrival. Percent weight change was monitored during rehydration to classify children as having "some dehydration" with weight change 3-9% or "severe dehydration" with weight change > 9%. Logistic regression analysis and Receiver-Operator Characteristic (ROC curves were used to evaluate the accuracy of aorta-to-IVC ratio as a predictor of dehydration severity.850 children were enrolled, of which 771 were included in the final analysis. Aorta to IVC ratio was a significant predictor of the percent dehydration in children with acute diarrhea, with each 1-point increase in the aorta to IVC ratio predicting a 1.1% increase in the percent dehydration of the child. However, the area under the ROC curve (0.60, sensitivity (67%, and specificity (49%, for predicting severe dehydration were all poor.Point-of-care ultrasound of the aorta-to-IVC ratio was statistically associated with volume status, but was not accurate enough to be used as an independent screening tool for dehydration in children under five years presenting with acute diarrhea in a resource-limited setting.

  3. Characterization of HIV-1 antiretroviral drug resistance after second-line treatment failure in Mali, a limited-resources setting

    Science.gov (United States)

    Maiga, Almoustapha Issiaka; Fofana, Djeneba Bocar; Cisse, Mamadou; Diallo, Fodié; Maiga, Moussa Youssoufa; Traore, Hamar Alassane; Maiga, Issouf Alassane; Sylla, Aliou; Fofana, Dionke; Taiwo, Babafemi; Murphy, Robert; Katlama, Christine; Tounkara, Anatole; Calvez, Vincent; Marcelin, Anne-Geneviève

    2012-01-01

    Objectives We describe the outcomes of second-line drug resistance profiles and predict the efficacy of drugs for third-line therapy in patients monitored without the benefit of plasma HIV-1 RNA viral load (VL) or resistance testing. Methods We recruited 106 HIV-1-infected patients after second-line treatment failure in Mali. VL was determined by the Abbott RealTime system and the resistance by the ViroSeq HIV-1 genotyping system. The resistance testing was interpreted using the latest version of the Stanford algorithm. Results Among the 106 patients, 93 had isolates successfully sequenced. The median age, VL and CD4 cells were respectively 35 years, 72 000 copies/mL and 146 cells/mm3. Patients were exposed to a median of 4 years of treatment and to six antiretrovirals. We found 20% of wild-type viruses. Resistance to etravirine was noted in 38%, to lopinavir in 25% and to darunavir in 12%. The duration of prior nucleos(t)ide reverse transcriptase inhibitor exposure was associated with resistance to abacavir (P < 0.0001) and tenofovir (P = 0.0001), and duration of prior protease inhibitor treatment with resistance to lopinavir (P < 0.0001) and darunavir (P = 0.06). Conclusion Long duration of therapy prior to failure was associated with high levels of resistance and is directly related to limited access to VL monitoring and delayed switches to second-line treatment, precluding efficacy of drugs for third-line therapy. This study underlines the need for governments and public health organizations to recommend the use of VL monitoring and also the availability of darunavir and raltegravir for third-line therapies in the context of limited-resource settings. PMID:22888273

  4. Resource use: a summary of the assessments of geothermal resource use limitations of Bruneau KGRA, Castle Creek KGRA, Crane Creek KGRA, Mountain Home KGRA, Vulcan KGRA

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.; Savage, N.; Gladwell, J.S.; Warnick, C.C.

    1979-02-23

    A brief overview is given of the physical, socioeconomic, and heritage resources of each KGRA summarized from the draft reports submitted to EG and G by subcontractors for this project. Included under the subheading of Physical Environment are geology, topography, and ecology with brief mention of climate, hydrology, and soils. Under Socioeconomic and Heritage Resources are demographic and economic data, land use and ownership, and known prehistoric and historic features. The information gaps are listed.

  5. The 'My five moments for hand hygiene' concept for the overcrowded setting in resource-limited healthcare systems.

    Science.gov (United States)

    Salmon, S; Pittet, D; Sax, H; McLaws, M L

    2015-10-01

    Hand hygiene is a core activity of patient safety for the prevention of healthcare-associated infections (HCAIs). To standardize hand hygiene practices globally the World Health Organization (WHO) released Guidelines on Hand Hygiene in Health Care and introduced the 'My five moments for hand hygiene' concept to define indications for hand hygiene rooted in an evidence-based model for transmission of micro-organisms by healthcare workers' (HCWs) hands. Central to the concept is the division of the healthcare environment into two geographical care zones, the patient zone and the healthcare zone, that requires the HCW to comply with specific hand hygiene moments. In resource-limited, overcrowded healthcare settings inadequate or no spatial separation between beds occurs frequently. These conditions challenge the HCW's ability to visualize and delineate patient zones. The 'My five moments for hand hygiene' concept has been adapted for these conditions with the aim of assisting hand hygiene educators, auditors, and HCWs to minimize ambiguity regarding shared patient zones and achieve the ultimate goal set by the WHO Guidelines--the reduction of infectious risks.

  6. Point-of-care ultrasound education for non-physician clinicians in a resource-limited emergency department.

    Science.gov (United States)

    Stolz, Lori A; Muruganandan, Krithika M; Bisanzo, Mark C; Sebikali, Mugisha J; Dreifuss, Bradley A; Hammerstedt, Heather S; Nelson, Sara W; Nayabale, Irene; Adhikari, Srikar; Shah, Sachita P

    2015-08-01

    To describe the outcomes and curriculum components of an educational programme to train non-physician clinicians working in a rural, Ugandan emergency department in the use of POC ultrasound. The use of point-of-care ultrasound was taught to emergency care providers through lectures, bedsides teaching and hands-on practical sessions. Lectures were tailored to care providers' knowledge base and available therapeutic means. Every ultrasound examination performed by these providers was recorded over 4.5 years. Findings of these examinations were categorised as positive, negative, indeterminate or procedural. Other radiologic studies ordered over this same time period were also recorded. A total of 22,639 patients were evaluated in the emergency department by emergency care providers, and 2185 point-of-care ultrasound examinations were performed on 1886 patients. Most commonly used were the focused assessment with sonography in trauma examination (53.3%) and echocardiography (16.4%). Point-of-care ultrasound studies were performed more frequently than radiology department-performed studies. Positive findings were documented in 46% of all examinations. We describe a novel curriculum for point-of-care ultrasound education of non-physician emergency practitioners in a resource-limited setting. These non-physician clinicians integrated ultrasound into clinical practice and utilised this imaging modality more frequently than traditional radiology department imaging with a large proportion of positive findings. © 2015 John Wiley & Sons Ltd.

  7. Outcome of Late Presentation of Posterior Urethral Valves in a Resource-Limited Economy: Challenges in Management

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    Odutola Israel Odetunde

    2012-01-01

    Full Text Available Delayed presentation of patients with posterior urethral valve with complications like severe urosepsis, uremia, and anemia are seen in our setting. Renal replacement therapy which should have been offered to these patients is not readily available for children in our country. The aim of this study is to determine the pattern of late presentation and outcome of management of posterior urethral valve in a resource-limited setting. A descriptive retrospective study (1997–2009 was conducted. Data including pattern of presentation, duration of symptoms, complications, and outcome of initial management were analyzed. Twenty-one patients were seen. The median age was 3 years (2 days–13 years. The mean duration of symptoms before presentation was 2.6 years. Nineteen patients (91% presented with urosepsis while 8 patients (36% presented with significant renal insufficiency. Laboratory findings varied from-mild-to marked elevation in serum creatinine. Radiological findings confirmed the diagnosis of posterior urethral valve. We concluded that late presentation is common in our setting. This is associated with high morbidity and mortality rates. Efforts at improving awareness and early diagnosis among the health team should be made to stem the tide.

  8. Ultrasound-guided Breast Biopsy in the Resource-limited Setting: An Initial Experience in Rural Uganda

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    Christopher R. Stark

    2017-06-01

    Full Text Available Purpose: To describe the methodology and initial experience behind creation of an ultrasoundguided percutaneous breast core biopsy program in rural Uganda. Methods and Materials: Imaging the World Africa (ITWA is the registered non-governmental organization division of Imaging the World (ITW, a not-for-profit organization whose primary aim is the integration of affordable high-quality ultrasound into rural health centers. In 2013, ITWA began the pilot phase of an IRB-approved breast care protocol at a rural health center in Uganda. As part of the protocol’s diagnostic arm, an ultrasound-guided percutaneous breast core biopsy training curriculum was implemented in tandem with creation of regionally supplied biopsy kits. Results: A surgeon at a rural regional referral hospital was successfully trained and certified to perform ultrasound-guided percutaneous breast core biopsies. Affordable and safe biopsy kits were created using locally available medical supplies with the cost of each kit totaling $10.62 USD. Conclusion: Successful implementation of an ultrasound-guided percutaneous breast core biopsy program in the resource-limited setting is possible and can be made sustainable through incorporation of local health care personnel and regionally supplied biopsy materials. Our hope is that ITWA’s initial experience in rural Uganda can serve as a model for similar programs in the future.

  9. Dimensions of Poverty and Health Outcomes Among People Living with HIV Infection: Limited Resources and Competing Needs.

    Science.gov (United States)

    Kalichman, Seth C; Hernandez, Dominica; Kegler, Christopher; Cherry, Chauncey; Kalichman, Moira O; Grebler, Tamar

    2015-08-01

    HIV infection is concentrated in populations living in poverty. We examined the overlapping and independent effects of multiple poverty indicators on HIV-related health status. Because substance use can create competing survival needs when resources are limited, we also sought to objectively measure expenditures on food relative to alcohol and tobacco products. To achieve these aims, 459 men and 212 women living with HIV infection in Atlanta, GA completed measures of socio-demographic and heath characteristics as well as multiple indicators of poverty including housing stability, transportation, food insecurity, and substance use. Participants were given a $30 grocery gift card for their participation and we collected receipts which were coded for alcohol (beer, wine, liquors) and tobacco purchases. Results showed that participants with unsuppressed HIV replication were significantly more likely to experience multiple indicators of poverty. In addition, one in four participants purchased alcohol or tobacco products with their gift cards, with as much as one-fourth of money spent on these products. A multivariable logistic regression model showed that food insecurity was independently associated with unsuppressed HIV, and purchasing alcohol or tobacco products did not moderate this association. Results confirm previous research to show the primacy of food insecurity in relation to HIV-related health outcomes. Competing survival needs, including addictive substances, should be addressed in programs that aim to alleviate poverty to enhance the health and well-being of people with HIV infection.

  10. The number of limiting resources in the environment controls the temporal diversity patterns in the algal benthos.

    Science.gov (United States)

    Larson, Chad A; Adumatioge, Larry; Passy, Sophia I

    2016-07-01

    The role of the number of limiting resources (NLR) on species richness has been the subject of much theoretical and experimental work. However, how the NLR controls temporal beta diversity and the processes of community assembly is not well understood. To address this knowledge gap, we initiated a series of laboratory microcosm experiments, exposing periphyton communities to a gradient of NLR from 0 to 3, generated by supplementation with nitrogen, phosphorus, iron, and all their combinations. We hypothesized that similarly to alpha diversity, shown to decrease with the NLR in benthic algae, temporal beta diversity would also decline due to filtering. Additionally, we predicted that the NLR would also affect turnover and community nestedness, which would show opposing responses. Indeed, as the NLR increased, temporal beta diversity decreased; turnover, indicative of competition, decreased; and nestedness, suggestive of complementarity, increased. Finally, the NLR determined the role of deterministic versus stochastic processes in community assembly, showing respectively an increasing and a decreasing trend. These results imply that the NLR has a much greater, yet still unappreciated influence on producer communities, constraining not only alpha diversity but also temporal dynamics and community assembly.

  11. Prevalence and Risk Factors Associated with Precancerous Cervical Cancer Lesions among HIV-Infected Women in Resource-Limited Settings

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    Peter Memiah

    2012-01-01

    Full Text Available Objective. To assess the prevalence and identified associated risk factors for precancerous cervical cancer lesions among HIV-infected women in resource-limited settings in Kenya. Methods. HIV-infected women attending the ART clinic at the Nazareth Hospital ART clinic between June 2009 and September 2010. Multivariate logistic regression model with odds ratios and 95% confidence intervals (CI were estimated after controlling for important covariates. Result. A total of 715 women were screened for cervical cancer. The median age of the participants was 40 years (range 18–69 years. The prevalence of precancerous lesions (CINI, CINII, CIN III, ICC was 191 (26.7%. After controlling for other variables in logistic regression analysis, cervical precancerous lesions were associated with not being on ART therapy; whereby non-ART were 2.21 times more likely to have precancerous lesions than ART patients [(aOR=2.21, 95% CI (1.28–3.83]. Conclusion. The prevalence of precancerous cervical lesions was lower than other similar settings. It is recommended that cancer screening of HIV-infected women should be an established practice. Availability and accessibility of these services can be done through their integration into HIV. Prompt initiation of HAART through an early enrollment into care has an impact on reducing the prevalence and progression of cervical precancerous lesions.

  12. Suicide of Women: an Extreme Condition? Suicidio de mujeres: ¿un caso extremo? Suicídio de Mulheres: uma Situação Limite?

    Directory of Open Access Journals (Sweden)

    Stela Meneghel

    2013-07-01

    Full Text Available Suicide, understood as a social fact, can be considered an extreme situation that represents a way out of an intense and unbearable suffering. This text reflects on the fragility of gender present in the life stories of women who committed suicide in cities in southern Brazil. Qualitative study that is part of a larger study entitled "It's possible to prevent the advance of the end? elderly suicide in Brazil and possibilities of health sector". The data were constructed using the technique of psychosocial autopsy trying to understand the life histories and factors related to suicide. The main themes present in the life stories of suicide women were classified as gender vulnerability and suicide as an extreme situation. We believe that gender norms, interpersonal conflicts and economic problems arising from work and illness were present in the lives of these women.  El suicidio, entendido como un hecho social, puede considerarse una situación extrema, ya que representa una forma de salir de un sufrimiento intenso e insoportable. Este texto tiene como objetivo reflexionar sobre la fragilidad de género que se encuentra en las historias de vida de las mujeres que se suicidaron en los municipios del sur de Brasil. Este estudio cualitativo es parte de un proyecto de investigación titulado "¿Es posible prevenir el avance del final? El suicidio de adultos mayores en Brasil y posibilidades del Sector de Salud". Los datos fueron construidos mediante la técnica de la autopsia psicológica, tratando de entender las historias de vida y los factores de riesgo relacionados con el suicidio. Los principales temas presentes en las historias de vida de las mujeres que se suicidaron fueron clasificadas como debilidades de género y el suicidio como una situación límite. Creemos que las normas de género y los conflictos interpersonales, así como problemas económicos que surgen del trabajo y las enfermedades estaban presentes en la vida de estas mujeres

  13. Speciation analysis of arsenic by selective hydride generation-cryotrapping-atomic fluorescence spectrometry with flame-in-gas-shield atomizer: achieving extremely low detection limits with inexpensive instrumentation.

    Science.gov (United States)

    Musil, Stanislav; Matoušek, Tomáš; Currier, Jenna M; Stýblo, Miroslav; Dědina, Jiří

    2014-10-21

    This work describes the method of a selective hydride generation-cryotrapping (HG-CT) coupled to an extremely sensitive but simple in-house assembled and designed atomic fluorescence spectrometry (AFS) instrument for determination of toxicologically important As species. Here, an advanced flame-in-gas-shield atomizer (FIGS) was interfaced to HG-CT and its performance was compared to a standard miniature diffusion flame (MDF) atomizer. A significant improvement both in sensitivity and baseline noise was found that was reflected in improved (4 times) limits of detection (LODs). The yielded LODs with the FIGS atomizer were 0.44, 0.74, 0.15, 0.17 and 0.67 ng L(-1) for arsenite, total inorganic, mono-, dimethylated As and trimethylarsine oxide, respectively. Moreover, the sensitivities with FIGS and MDF were equal for all As species, allowing for the possibility of single species standardization with arsenate standard for accurate quantification of all other As species. The accuracy of HG-CT-AFS with FIGS was verified by speciation analysis in two samples of bottled drinking water and certified reference materials, NRC CASS-5 (nearshore seawater) and SLRS-5 (river water) that contain traces of methylated As species. As speciation was in agreement with results previously reported and sums of all quantified species corresponded with the certified total As. The feasibility of HG-CT-AFS with FIGS was also demonstrated by the speciation analysis in microsamples of exfoliated bladder epithelial cells isolated from human urine. The results for the sums of trivalent and pentavalent As species corresponded well with the reference results obtained by HG-CT-ICPMS (inductively coupled plasma mass spectrometry).

  14. The limits of drought-induced rapid cold-hardening: extremely brief, mild desiccation triggers enhanced freeze-tolerance in Eurosta solidaginis larvae.

    Science.gov (United States)

    Gantz, J D; Lee, Richard E

    2015-02-01

    Rapid cold-hardening (RCH) is a highly conserved response in insects that induces physiological changes within minutes to hours of exposure to low temperature and provides protection from chilling injury. Recently, a similar response, termed drought-induced RCH, was described following as little as 6h of desiccation, producing a loss of less than 10% of fresh mass. In this study, we investigated the limits and mechanisms of this response in larvae of the goldenrod gall fly Eurosta solidaginis (Diptera, Tephritidae). The cold-hardiness of larvae increased markedly after as few as 2h of desiccation and a loss of less than 1% fresh mass, as organismal survival increased from 8% to 41% following exposure to -18 °C. Tissue-level effects of desiccation were observed within 1h, as 87% of midgut cells from desiccated larvae remained viable following freezing compared to 57% of controls. We also demonstrated that drought-induced RCH occurs independently of neuroendocrine input, as midgut tissue desiccated ex vivo displayed improved freeze-tolerance relative to control tissue (78-11% survival, respectively). Finally, though there was an increase in hemolymph osmolality beyond the expected effects of the osmo-concentration of solutes during dehydration, we determined that this increase was not due to the synthesis of glycerol, glucose, sorbitol, or trehalose. Our results indicate that E. solidaginis larvae are extremely sensitive to desiccation, which is a triggering mechanism for one or more physiological pathways that confer enhanced freeze-tolerance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Esophageal atresia associated with anorectal malformation: Is the outcome better after surgery in two stages in a limited resources scenario?

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    Sunita Singh

    2012-01-01

    Full Text Available Aims: To analyze whether outcome of neonates having esophageal atresia with or without tracheoesophageal fistula (EA±TEF associated with anorectal malformation (ARM can be improved by doing surgery in 2 stages. Materials and Methods : A prospective study of neonates having both EA±TEF and ARM from 2004 to 2011. The patients with favorable parameters were operated in a single stage, whereas others underwent first-stage decompression surgery for ARM. Thereafter, once septicemia was under control and ventilator care available, second-stage surgery for EA±TEF was performed. Results: Total 70 neonates (single stage = 20, 2 stages = 30, expired after colostomy = 9, only EA±TEF repair needed = 11 were enrolled. The admission rate for this association was 1 per 290. Forty-one percent (24/70 neonates had VACTERL association and 8.6% (6/70 neonates had multiple gastrointestinal atresias. Sepsis screen was positive in 71.4% (50/70. The survival was 45% (9/20 in neonates operated in a single stage and 53.3% (16/30 when operated in 2 stages (P = 0.04. Data analysis of 50 patients revealed that the survived neonates had significantly better birth weight, better gestational age, negative sepsis screen, no cardiac diseases, no pneumonia, and 2-stage surgery (P value 0.002, 0.003, 0.02, 0.02, 0.04, and 0.04, respectively. The day of presentation and abdominal distension had no significant effect (P value 0.06 and 0.06, respectively. This was further supported by stepwise logistic regression analysis. Conclusions: In a limited resources scenario, the survival rate of babies with this association can be improved by treating ARM first and then for EA±TEF in second stage, once mechanical ventilator care became available and sepsis was under control.

  16. Level of data quality from Health Management Information Systems in a resources limited setting and its associated factors, eastern Ethiopia

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    Kidist Teklegiorgis

    2016-04-01

    Full Text Available Background: A Health Information System (HIS is a system that integrates data collection, processing, reporting, and use of the information necessary for improving health service effectiveness and efficiency through better management at all levels of health services. Despite the credible use of HIS for evidence-based decision-making, countries with the highest burden of ill health and the most in need of accurate and timely data have the weakest HIS in the vast majority of world’s poorest countries. Although a Health Management Information System (HMIS forms a backbone for strong health systems, most developing countries still face a challenge in strengthening routine HIS. The main focus of this study was to assess the current HIS performance and identify factors affecting data quality in a resource-limited setting, such as Ethiopian health facilities.Methods: A cross-sectional study was conducted by using structured questionnaires in Dire Dawa Administration health facilities. All unit and/or department heads from all government health facilities were selected. The data was analysed using STATA version 11. Frequency and percentages were computed to present the descriptive findings. Association between variables was computed using binary logistic regression.Results: Over all data quality was found to be 75.3% in unit and/or departments. Trained staff to fill format, decision based on supervisor directives and department heads seek feedback were significantly associated with data quality and their magnitudes were (AOR = 2.253, 95% CI [1.082, 4.692], (AOR = 2.131, 95% CI [1.073, 4.233] and (AOR = 2.481, 95% CI [1.262, 4.876], respectively.Conclusion: Overall data quality was found to be below the national expectation level. Low data quality was found at health posts compared to health centres and hospitals. There was also a shortage of assigned HIS personnel, separate HIS offices, and assigned budgets for HIS across all units and/or departments.

  17. Scaling-up the use of generic antiretrovirals in resource-limited countries: generic drugs for health.

    Science.gov (United States)

    Beck, Eduard J; Passarelli, Carlos; Lui, Iris; Guichard, Anne-Claire; Simao, Mariangela; De Lay, Paul; Loures, Luiz

    2014-01-01

    The number of people living with HIV (PLHIV) continues to increase around the world because of the increasing number on antiretroviral therapy (ART) and their associated increase of life expectancy, in addition to the number of people newly infected with HIV each year. Unless a 'cure' can be found for HIV infection, PLHIV can anticipate the need to take antiretroviral drugs (ARVs) for the rest of their lives. Because ARVs are now being used for HIV prevention, as well as for therapeutic purposes, the need for effective, affordable ARVs with few adverse effects will continue to rise. It is important to note that the dramatic growth in treatment coverage of PLHIV seen during the past decade has been primarily due to the increased use of generic ARVs. Thus, there will be a need to scale-up the research and development, production, distribution and access to generic ARVs and ART regimens. However, these processes must occur within national and international regulated free-market economic systems and must deal with increasingly multifaceted patent issues affecting the price while ensuring the quality of the ARVs. National and international regulatory mechanisms will have to evolve, which will affect broader national and international economic and trade issues. Because of the complexity of these issues, the Editors of this Supplement conceived of asking experts in their fields to describe the various steps from relevant research and development, to production of generic ARVs, their delivery to countries and subsequently to PLHIV in low- and middle-income countries. A main objective was to highlight how these steps are interrelated, how the production and delivery of these drugs to PLHIV in resource-limited countries can be made more effective and efficient, and what the lessons are for the production and delivery of a broader set of drugs to people in low- and middle-income countries.

  18. Micro-economic impact of congenital heart surgery: results of a prospective study from a limited-resource setting.

    Directory of Open Access Journals (Sweden)

    Manu Raj

    Full Text Available The microeconomic impact of surgery for congenital heart disease is unexplored, particularly in resource limited environments. We sought to understand the direct and indirect costs related to congenital heart surgery and its impact on Indian households from a family perspective.Baseline and first follow-up data of 644 consecutive children admitted for surgery for congenital heart disease (March 2013 - July 2014 in a tertiary referral hospital in Central Kerala, South India was collected prospectivelyfrom parents through questionnaires using a semi-structured interview schedule.The median age was 8.2 months (IQR: 3.0- 36.0 months. Most families belonged to upper middle (43.0% and lower middle (35.7% socioeconomic class. Only 3.9% of families had some form of health insurance. The median expense for the admission and surgery was INR 201898 (IQR: 163287-266139 [I$ 11989 (IQR: 9696-15804], which was 0.93 (IQR: 0.52-1.49 times the annual family income of affected patients. Median loss of man-days was 35 (IQR: 24-50 and job-days was 15 (IQR: 11-24. Surgical risk category and hospital stay duration significantly predicted higher costs. One in two families reported overwhelming to high financial stress during admission period for surgery. Approximately half of the families borrowed money during the follow up period after surgery.Surgery for congenital heart disease results in significant financial burden for majority of families studied. Efforts should be directed at further reductions in treatment costs without compromising the quality of care together with generating financial support for affected families.

  19. Applicability of first-trimester combined screening for fetal trisomy 21 in a resource-limited setting in mainland China.

    Science.gov (United States)

    Li, B; Sahota, D S; Lao, T T; Xu, J; Hu, S Q; Zhang, L; Liu, Q Y; Sun, Q; Tang, D; Ma, R M

    2016-09-01

    To assess the feasibility and performance of the first-trimester combined screening test for trisomy 21 in a resource-limited setting in mainland China. Prospective observational cohort study. First Affiliated Hospital of Kunming Medical University, China. Ten thousand four hundred and forty-two pregnant women requesting first-trimester screening. The combined screening test was performed from May 2012 to December 2014. Women with a high-risk result (≥1:600) were offered further confirmatory tests after counselling. The threshold for high risk was determined by Monte Carlo simulation to achieve a 5% false-positive rate according to the local age distribution. Pregnancy outcome and screening results were recorded for all women and monthly audits were conducted. Sensitivity, screen positive rate, cost per case of Down syndrome detected. Six hundred and ten women (5.8% of the total screened) had a high-risk screening test, of whom 274 (44.9%) underwent a diagnostic test and 169 (27.7%) opted for a noninvasive prenatal screening test (NIPT); 160 (26.2%) declined further testing after counselling. The pregnancy outcome was available for 10 174 (97.4%) of the women. The observed incidence of Down syndrome was 0.13% (1/750). All 14 women with a trisomy 21 pregnancy had a high-risk screening test result. The cost per Down syndrome detected was RMB596 686 compared with RMB1.79 million if all had been screened by NIPT. The combined screening test appears to be a more cost-effective strategy in mainland China. Screening performance in China would be improved by adopting Chinese-specific models, external quality control and assurance, and establishing risk thresholds appropriate for the age distribution of the population. Combined first-trimester Downs screening in China was improved by adopting Chinese-specific models and external QC. © 2016 Royal College of Obstetricians and Gynaecologists.

  20. Allometric Scaling and Resource Limitations Model of Tree Heights: Part 1. Model Optimization and Testing over Continental USA

    Directory of Open Access Journals (Sweden)

    Ramakrishna R. Nemani

    2013-01-01

    Full Text Available A methodology to generate spatially continuous fields of tree heights with an optimized Allometric Scaling and Resource Limitations (ASRL model is reported in this first of a multi-part series of articles. Model optimization is performed with the Geoscience Laser Altimeter System (GLAS waveform data. This methodology is demonstrated by mapping tree heights over forested lands in the continental USA (CONUS at 1 km spatial resolution. The study area is divided into 841 eco-climatic zones based on three forest types, annual total precipitation classes (30 mm intervals and annual average temperature classes (2 °C intervals. Three model parameters (area of single leaf, α, exponent for canopy radius, η, and root absorption efficiency, γ were selected for optimization, that is, to minimize the difference between actual and potential tree heights in each of the eco-climatic zones over the CONUS. Tree heights predicted by the optimized model were evaluated against GLAS heights using a two-fold cross validation approach (R2 = 0.59; RMSE = 3.31 m. Comparison at the pixel level between GLAS heights (mean = 30.6 m; standard deviation = 10.7 and model predictions (mean = 30.8 m; std. = 8.4 were also performed. Further, the model predictions were compared to existing satellite-based forest height maps. The optimized ASRL model satisfactorily reproduced the pattern of tree heights over the CONUS. Subsequent articles in this series will document further improvements with the ultimate goal of mapping tree heights and forest biomass globally.

  1. Baseline severe anaemia should not preclude use of zidovudine in antiretroviral-eligible patients in resource-limited settings

    Science.gov (United States)

    2010-01-01

    Background Stavudine is no longer recommended as part of first-line therapy for patients initiating antiretroviral therapy (ART) in Uganda. Most patients are currently initiated on zidovudine-containing regimens, which can induce anaemia. We investigated the risk factors for early severe anaemia in the first six months of ART initiation. Methods We defined baseline (ART initiation) anaemia as haemoglobin (Hb) ≤9.5 g/dL, baseline severe anaemia as Hb ≤8 g/dL, and early severe anaemia as Hb ≤8 g/dL within six months of ART initiation. Risk factors for the development of early severe anaemia were analyzed using a multivariable logistic regression model. Results In total, 5494 patients initiated ART, 821 (15%) had baseline anaemia, and 296 (5%) had baseline severe anaemia. Early severe anaemia occurred in 109 (4%) of 3105 patients who had at least one Hb measurement in the first six months on ART. Patients with baseline anaemia had a larger increase in Hb (median g/dL [IQR]) within the first six months compared with non-anaemic patients (2.9 [1.7, 4.6] vs. 0.7 [-0.2, 1.7], p anaemia OR 5.27 (95% CI 3.00 - 9.26) were associated with early severe anaemia. Initiation on a zidovudine-based regimen was not associated with an increased risk of early severe anaemia. Conclusions Among patients in an urban HIV clinic in Uganda, severe anaemia is modestly prevalent at ART initiation and improves with ART in the majority of patients. These data suggest that baseline severe anaemia should not be used as a criterion for avoiding the use of zidovudine in patients initiating ART in resource-limited settings. PMID:21047391

  2. Role of nutrition in HIV infection: review of evidence for more effective programming in resource-limited settings.

    Science.gov (United States)

    de Pee, Saskia; Semba, Richard D

    2010-12-01

    HIV infection and malnutrition negatively reinforce each other. For program guidance, to review evidence on the relationship of HIV infection and malnutrition in adults in resource-limited settings. Adequate nutritional status supports immunity and physical performance. Weight loss, caused by low dietary intake (loss of appetite, mouth ulcers, food insecurity), malabsorption, and altered metabolism, is common in HIV infection. Regaining weight, particularly muscle mass, requires antiretroviral therapy (ART), treatment of opportunistic infections, consumption of a balanced diet, physical activity, mitigation of side effects, and perhaps appetite stimulants and growth hormone. Correcting nutritional status becomes more difficult as infection progresses. Studies document widespread micronutrient deficiencies among HIV-infected people. However, supplement composition, patient characteristics, and treatments vary widely across intervention studies. Therefore, the World Health Organization (WHO) recommends ensuring intake of 1 Recommended Nutrient Intake (RNI) of each required micronutrient, which may require taking micronutrient supplements. Few studies have assessed the impact of food supplements. Because the mortality risk in patients receiving ART increases with lower body mass index (BMI), improving the BMI seems important. Whether this requires provision of food supplements depends on the patient's diet and food security. It appears that starting ART improves BMI and that ready-to-use fortified spreads and fortified-blended foods further increase BMI (the effect is somewhat less with fortified-blended foods). The studies are too small to assess effects on mortality. Once ART has been established and malnutrition treated, the nutritional quality of the diet remains important, also because of ART's long-term metabolic effects (dyslipidemia, insulin resistance, obesity). Food insecurity should also be addressed if it prevents adequate energy intake and reduces

  3. Micro-economic impact of congenital heart surgery: results of a prospective study from a limited-resource setting.

    Science.gov (United States)

    Raj, Manu; Paul, Mary; Sudhakar, Abish; Varghese, Anu Alphonse; Haridas, Aareesh Chittulliparamb; Kabali, Conrad; Kumar, Raman Krishna

    2015-01-01

    The microeconomic impact of surgery for congenital heart disease is unexplored, particularly in resource limited environments. We sought to understand the direct and indirect costs related to congenital heart surgery and its impact on Indian households from a family perspective. Baseline and first follow-up data of 644 consecutive children admitted for surgery for congenital heart disease (March 2013 - July 2014) in a tertiary referral hospital in Central Kerala, South India was collected prospectivelyfrom parents through questionnaires using a semi-structured interview schedule. The median age was 8.2 months (IQR: 3.0- 36.0 months). Most families belonged to upper middle (43.0%) and lower middle (35.7%) socioeconomic class. Only 3.9% of families had some form of health insurance. The median expense for the admission and surgery was INR 201898 (IQR: 163287-266139) [I$ 11989 (IQR: 9696-15804)], which was 0.93 (IQR: 0.52-1.49) times the annual family income of affected patients. Median loss of man-days was 35 (IQR: 24-50) and job-days was 15 (IQR: 11-24). Surgical risk category and hospital stay duration significantly predicted higher costs. One in two families reported overwhelming to high financial stress during admission period for surgery. Approximately half of the families borrowed money during the follow up period after surgery. Surgery for congenital heart disease results in significant financial burden for majority of families studied. Efforts should be directed at further reductions in treatment costs without compromising the quality of care together with generating financial support for affected families.

  4. Design of a Novel Low Cost Point of Care Tampon (POCkeT) Colposcope for Use in Resource Limited Settings.

    Science.gov (United States)

    Lam, Christopher T; Krieger, Marlee S; Gallagher, Jennifer E; Asma, Betsy; Muasher, Lisa C; Schmitt, John W; Ramanujam, Nimmi

    2015-01-01

    Current guidelines by WHO for cervical cancer screening in low- and middle-income countries involves visual inspection with acetic acid (VIA) of the cervix, followed by treatment during the same visit or a subsequent visit with cryotherapy if a suspicious lesion is found. Implementation of these guidelines is hampered by a lack of: trained health workers, reliable technology, and access to screening facilities. A low cost ultra-portable Point of Care Tampon based digital colposcope (POCkeT Colposcope) for use at the community level setting, which has the unique form factor of a tampon, can be inserted into the vagina to capture images of the cervix, which are on par with that of a state of the art colposcope, at a fraction of the cost. A repository of images to be compiled that can be used to empower front line workers to become more effective through virtual dynamic training. By task shifting to the community setting, this technology could potentially provide significantly greater cervical screening access to where the most vulnerable women live. The POCkeT Colposcope's concentric LED ring provides comparable white and green field illumination at a fraction of the electrical power required in commercial colposcopes. Evaluation with standard optical imaging targets to assess the POCkeT Colposcope against the state of the art digital colposcope and other VIAM technologies. Our POCkeT Colposcope has comparable resolving power, color reproduction accuracy, minimal lens distortion, and illumination when compared to commercially available colposcopes. In vitro and pilot in vivo imaging results are promising with our POCkeT Colposcope capturing comparable quality images to commercial systems. The POCkeT Colposcope is capable of capturing images suitable for cervical lesion analysis. Our portable low cost system could potentially increase access to cervical cancer screening in limited resource settings through task shifting to community health workers.

  5. Design of a Novel Low Cost Point of Care Tampon (POCkeT Colposcope for Use in Resource Limited Settings.

    Directory of Open Access Journals (Sweden)

    Christopher T Lam

    Full Text Available Current guidelines by WHO for cervical cancer screening in low- and middle-income countries involves visual inspection with acetic acid (VIA of the cervix, followed by treatment during the same visit or a subsequent visit with cryotherapy if a suspicious lesion is found. Implementation of these guidelines is hampered by a lack of: trained health workers, reliable technology, and access to screening facilities. A low cost ultra-portable Point of Care Tampon based digital colposcope (POCkeT Colposcope for use at the community level setting, which has the unique form factor of a tampon, can be inserted into the vagina to capture images of the cervix, which are on par with that of a state of the art colposcope, at a fraction of the cost. A repository of images to be compiled that can be used to empower front line workers to become more effective through virtual dynamic training. By task shifting to the community setting, this technology could potentially provide significantly greater cervical screening access to where the most vulnerable women live. The POCkeT Colposcope's concentric LED ring provides comparable white and green field illumination at a fraction of the electrical power required in commercial colposcopes. Evaluation with standard optical imaging targets to assess the POCkeT Colposcope against the state of the art digital colposcope and other VIAM technologies.Our POCkeT Colposcope has comparable resolving power, color reproduction accuracy, minimal lens distortion, and illumination when compared to commercially available colposcopes. In vitro and pilot in vivo imaging results are promising with our POCkeT Colposcope capturing comparable quality images to commercial systems.The POCkeT Colposcope is capable of capturing images suitable for cervical lesion analysis. Our portable low cost system could potentially increase access to cervical cancer screening in limited resource settings through task shifting to community health workers.

  6. Shrinking Sea Ice, Thawing Permafrost, Bigger Storms, and Extremely Limited Data - Addressing Information Needs of Stakeholders in Western Alaska Through Participatory Decisions and Collaborative Science.

    Science.gov (United States)

    Murphy, K. A.; Reynolds, J.

    2015-12-01

    Communities, Tribes, and decision makers in coastal western Alaska are being impacted by declining sea ice, sea level rise, changing storm patterns and intensities, and increased rates of coastal erosion. Relative to their counterparts in the contiguous USA, their ability to plan for and respond to these changes is constrained by the region's generally meager or non-existent information base. Further, the information needs and logistic challenges are of a scale that perhaps can be addressed only through strong, strategic collaboration. Landscape Conservation Cooperatives (LCCs) are fundamentally about applied science and collaboration, especially collaborative decision making. The Western Alaska LCC has established a process of participatory decision making that brings together researchers, agency managers, local experts from Tribes and field specialists to identify and prioritize shared information needs; develop a course of action to address them by using the LCC's limited resources to catalyze engagement, overcome barriers to progress, and build momentum; then ensure products are delivered in a manner that meets decision makers' needs. We briefly review the LCC's activities & outcomes from the stages of (i) collaborative needs assessment (joint with the Alaska Climate Science Center and the Alaska Ocean Observing System), (ii) strategic science activities, and (iii) product refinement and delivery. We discuss lessons learned, in the context of our recent program focused on 'Changes in Coastal Storms and Their Impacts' and current collaborative efforts focused on delivery of Coastal Resiliency planning tools and results from applied science projects. Emphasis is given to the various key interactions between scientists and decision makers / managers that have been promoted by this process to ensure alignment of final products to decision maker needs.

  7. Maximum-throughput scheduling with limited resources for iterative data-flow graphs by means of the scheduling-range chart

    NARCIS (Netherlands)

    Heemstra de Groot, S.M.; Herrmann, O.E.

    1990-01-01

    An algorithm based on an alternative scheduling approach for iterative acyclic and cyclid DFGs (data-flow graphs) with limited resources that exploits inter- and intra-iteration parallelism is presented. The method is based on guiding the scheduling algorithm with the information supplied by a

  8. Tenofovir-induced acute kidney injury in HIV-infected patients in western India: a resource limited setting perspective

    Directory of Open Access Journals (Sweden)

    A Sadre

    2012-11-01

    Full Text Available Background and objective Tenofovir use in HIV positive patients is associated with 0.5–2.5% risk of acute kidney injury (AKI. Data on AKI due to tenofovir use in resource limited settings like India is sparse. Objective of this study is to determine incidence, risk factors and outcome of tenofovir-induced acute kidney injury (serum creatinine>2 mg/dl or creatinine clearance decrease by 50% compared to baseline in HIV infected patients attending tertiary level HIV clinic in Western India. Methods All patients enrolled at the clinic from 2009 to 2012 who were initiated on tenofovir-based ART and had regular follow up creatinine clearance values available were included in this retrospective observational cohort analysis. Patients already on tenofovir-based ART during enrollment were also included. Summary of results 512 patients were enrolled in the study with 70% being males. Average age of the cohort was 41 years, average body weight 56 kilograms and median baseline CD4 count 164 cells/mm3. Mean baseline creatinine clearance was 90 ml/min. Median duration of follow up was 26 months. Tenofovir-induced AKI developed in 25 patients (incidence 4.88 %. Median time to developing AKI was 6 months. On stopping tenofovir, 15 patients had complete recovery of renal function, 5 had partial recovery while 5 patients died. Hemodialysis as a treatment option was used in 3 patients. Age>50 yrs (p=0.001, baseline creatinine clearance<50 ml/min (p=0.0001, diabetes mellitus (p=0.0001, use of tenofovir with protease inhibitors (p=0.001, presence of renal calculus disease (p =0.0001 and use of concomitant nephrotoxic medications (p=0.001 were significantly associated with risk of tenofovir AKI on applying Pearson's Chi square test. Conclusions Incidence of tenofovir-induced AKI in our cohort is higher than previously reported and could be attributed to lower body weight, lower baseline creatinine clearance, higher incidence of advanced HIV disease and higher

  9. Incidence of WHO stage 3 and 4 conditions following initiation of anti-retroviral therapy in resource limited settings.

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    Andrea J Curtis

    Full Text Available OBJECTIVES: To determine the incidence of WHO clinical stage 3 and 4 conditions during early anti-retroviral therapy (ART in resource limited settings (RLS. DESIGN/SETTING: A descriptive analysis of routine program data collected prospectively from 25 Médecins Sans Frontières supported HIV treatment programs in eight countries between 2002 and 2010. SUBJECTS/PARTICIPANTS: 35,349 study participants with median follow-up on ART of 1.33 years (IQR 0.51-2.41. OUTCOME MEASURES: Incidence in 100 person-years of WHO stage 3 or 4 conditions during 5 periods after ART initiation. Diagnoses of conditions were made according to WHO criteria and relied upon clinical assessments supported by basic laboratory investigations. RESULTS: The incidence of any WHO clinical stage 3 or 4 condition over 3 years was 40.02 per 100 person-years (31.77 for stage 3 and 8.25 for stage 4. The incidence of stage 3 and 4 conditions fell by over 97% between months 0-3 and months 25-36 (77.81 to 2.40 for stage 3 and 28.70 to 0.64 for stage 4. During months 0-3 pulmonary tuberculosis was the most common condition diagnosed in adults (incidence 22.24 per 100 person-years and children aged 5-14 years (25.76 and oral candidiasis was the most common in children <5 years (25.79. Overall incidences were higher in Africa compared with Asia (43.98 versus 12.97 for stage 3 and 8.98 versus 7.05 for stage 4 conditions, p<0.001. Pulmonary tuberculosis, weight loss, oral and oesophageal candidiasis, chronic diarrhoea, HIV wasting syndrome and severe bacterial infections were more common in Africa. Extra-pulmonary tuberculosis, non-tuberculous mycobacterial infection, cryptococcosis, penicilliosis and toxoplasmosis were more common in Asia. CONCLUSIONS: The incidence of WHO stage 3 and 4 conditions during the early period after ART initiation in RLS is high, but greatly reduces over time. This is likely due to both the benefits of ART and deaths of the sickest patients occurring shortly

  10. Scaling Up the 2010 World Health Organization HIV Treatment Guidelines in Resource-Limited Settings: A Model-Based Analysis

    Science.gov (United States)

    Walensky, Rochelle P.; Wood, Robin; Ciaranello, Andrea L.; Paltiel, A. David; Lorenzana, Sarah B.; Anglaret, Xavier; Stoler, Adam W.; Freedberg, Kenneth A.

    2010-01-01

    Background The new 2010 World Health Organization (WHO) HIV treatment guidelines recommend earlier antiretroviral therapy (ART) initiation (CD4<350 cells/µl instead of CD4<200 cells/µl), multiple sequential ART regimens, and replacement of first-line stavudine with tenofovir. This paper considers what to do first in resource-limited settings where immediate implementation of all of the WHO recommendations is not feasible. Methods and Findings We use a mathematical model and local input data to project clinical and economic outcomes in a South African HIV-infected cohort (mean age = 32.8 y, mean CD4 = 375/µl). For the reference strategy, we assume that all patients initiate stavudine-based ART with WHO stage III/IV disease and receive one line of ART (stavudine/WHO/one-line). We rank—in survival, cost-effectiveness, and equity terms—all 12 possible combinations of the following: (1) stavudine replacement with tenofovir, (2) ART initiation (by WHO stage, CD4<200 cells/µl, or CD4<350 cells/µl), and (3) one or two regimens, or lines, of available ART. Projected life expectancy for the reference strategy is 99.0 mo. Considering each of the guideline components separately, 5-y survival is maximized with ART initiation at CD4<350 cells/µl (stavudine/<350/µl/one-line, 87% survival) compared with stavudine/WHO/two-lines (66%) and tenofovir/WHO/one-line (66%). The greatest life expectancies are achieved via the following stepwise programmatic additions: stavudine/<350/µl/one-line (124.3 mo), stavudine/<350/µl/two-lines (177.6 mo), and tenofovir/<350/µl/two-lines (193.6 mo). Three program combinations are economically efficient: stavudine/<350/µl/one-line (cost-effectiveness ratio, US$610/years of life saved [YLS]), tenofovir/<350/µl/one-line (US$1,140/YLS), and tenofovir/<350/µl/two-lines (US$2,370/YLS). Conclusions In settings where immediate implementation of all of the new WHO treatment guidelines is not feasible, ART initiation at CD4<350 cells

  11. Scaling up the 2010 World Health Organization HIV Treatment Guidelines in resource-limited settings: a model-based analysis.

    Directory of Open Access Journals (Sweden)

    Rochelle P Walensky

    Full Text Available BACKGROUND: The new 2010 World Health Organization (WHO HIV treatment guidelines recommend earlier antiretroviral therapy (ART initiation (CD4<350 cells/µl instead of CD4<200 cells/µl, multiple sequential ART regimens, and replacement of first-line stavudine with tenofovir. This paper considers what to do first in resource-limited settings where immediate implementation of all of the WHO recommendations is not feasible. METHODS AND FINDINGS: We use a mathematical model and local input data to project clinical and economic outcomes in a South African HIV-infected cohort (mean age = 32.8 y, mean CD4 = 375/µl. For the reference strategy, we assume that all patients initiate stavudine-based ART with WHO stage III/IV disease and receive one line of ART (stavudine/WHO/one-line. We rank-in survival, cost-effectiveness, and equity terms-all 12 possible combinations of the following: (1 stavudine replacement with tenofovir, (2 ART initiation (by WHO stage, CD4<200 cells/µl, or CD4<350 cells/µl, and (3 one or two regimens, or lines, of available ART. Projected life expectancy for the reference strategy is 99.0 mo. Considering each of the guideline components separately, 5-y survival is maximized with ART initiation at CD4<350 cells/µl (stavudine/<350/µl/one-line, 87% survival compared with stavudine/WHO/two-lines (66% and tenofovir/WHO/one-line (66%. The greatest life expectancies are achieved via the following stepwise programmatic additions: stavudine/<350/µl/one-line (124.3 mo, stavudine/<350/µl/two-lines (177.6 mo, and tenofovir/<350/µl/two-lines (193.6 mo. Three program combinations are economically efficient: stavudine/<350/µl/one-line (cost-effectiveness ratio, US$610/years of life saved [YLS], tenofovir/<350/µl/one-line (US$1,140/YLS, and tenofovir/<350/µl/two-lines (US$2,370/YLS. CONCLUSIONS: In settings where immediate implementation of all of the new WHO treatment guidelines is not feasible, ART initiation at CD4<350 cells

  12. As reformas do Estado, da saúde e recursos humanos: limites e possibilidades The state reforms, health reforms and the human resources: limits and possibilities

    Directory of Open Access Journals (Sweden)

    Celia Regina Pierantoni

    2001-01-01

    Full Text Available As transformações observadas a partir da implementação da reforma do Estado brasileiro destacam antigos problemas e introduzem outros novos para a área de recursos humanos em saúde. Este trabalho examina o desenvolvimento da área de recursos humanos (RH nas políticas públicas, tendo como referencial as reformas da política nacional de saúde na década de 1990 no Brasil. Aponta para a necessidade de ampliação e aprofundamento do conhecimento sobre o trabalho desenvolvido na área de saúde que envolve a abordagem da administração geral, da sociologia do trabalho e das profissões e especialidades, do desenvolvimento tecnológico, das análises econômicas, dos processos de aprendizagem, entre outras. Identifica dimensões críticas para a abordagem de recursos humanos em saúde que necessitam ser analisadas e acompanhadas de mecanismos de intervenção específica e não excludentes: a dimensão gerencial, a dimensão estrutural e a dimensão regulatória. Destaca a necessidade de intervenções que reintroduzam os profissionais de saúde na centralidade do debate como participantes da implementação das políticas em seus aspectos político, administrativo, técnico e social.The transformations brought by the Brazilian State reforms detach old problems and present new ones to health human resources. This paper examines the development of human resources in public policy concerning the State reforms in the 90's. It points out the need of enlargement and improvement of the knowledge about the work developed in health which envolves general administration, professional sociology, technologic knowledge, economical analyses, learning processes, among others. It identifies three critical dimensions to the approach of health human resources that need to be analyzed and followed by special mechanisms of specific and not excluding intervention: the management, the structural and the regulatory dimensions. It emphasizes the need to

  13. Extreme Heat

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  14. Mandelbrot's Extremism

    NARCIS (Netherlands)

    Beirlant, J.; Schoutens, W.; Segers, J.J.J.

    2004-01-01

    In the sixties Mandelbrot already showed that extreme price swings are more likely than some of us think or incorporate in our models.A modern toolbox for analyzing such rare events can be found in the field of extreme value theory.At the core of extreme value theory lies the modelling of maxima

  15. Research on the feasibility and operability of human resources accounting and limited companies%人力资源会计与股份有限公司

    Institute of Scientific and Technical Information of China (English)

    刘祥颖

    2001-01-01

    人力资源会计与股份有限公司都是我国新兴的产物,二者的融合在实践中未曾尝试.本文从理论上初步探讨了我国建立人力资源会计和股份有限公司的特殊性,并阐明了人力资源会计应用于股份有限公司的可行性与操作性.%Both human resources accoungting and limited companies are thenew and developing products in China. However,no attempt has been made to combine them in practice. This article makes a preliminary theoretcal study of the basis on which human resources accounting is established in China and discusses the limitations of limited company system. As to the harmonization of the human factorsz,this article expounds the model of human resources accounting that it can be combined with limited company system in respect of feasibilit and operatability.

  16. Lessons learned developing a diagnostic tool for HIV-associated dementia feasible to implement in resource-limited settings: pilot testing in Kenya.

    Directory of Open Access Journals (Sweden)

    Judith Kwasa

    Full Text Available To conduct a preliminary evaluation of the utility and reliability of a diagnostic tool for HIV-associated dementia (HAD for use by primary health care workers (HCW which would be feasible to implement in resource-limited settings.In resource-limited settings, HAD is an indication for anti-retroviral therapy regardless of CD4 T-cell count. Anti-retroviral therapy, the treatment for HAD, is now increasingly available in resource-limited settings. Nonetheless, HAD remains under-diagnosed likely because of limited clinical expertise and availability of diagnostic tests. Thus, a simple diagnostic tool which is practical to implement in resource-limited settings is an urgent need.A convenience sample of 30 HIV-infected outpatients was enrolled in Western Kenya. We assessed the sensitivity and specificity of a diagnostic tool for HAD as administered by a primary HCW. This was compared to an expert clinical assessment which included examination by a physician, neuropsychological testing, and in selected cases, brain imaging. Agreement between HCW and an expert examiner on certain tool components was measured using Kappa statistic.The sample was 57% male, mean age was 38.6 years, mean CD4 T-cell count was 323 cells/µL, and 54% had less than a secondary school education. Six (20% of the subjects were diagnosed with HAD by expert clinical assessment. The diagnostic tool was 63% sensitive and 67% specific for HAD. Agreement between HCW and expert examiners was poor for many individual items of the diagnostic tool (K = .03-.65. This diagnostic tool had moderate sensitivity and specificity for HAD. However, reliability was poor, suggesting that substantial training and formal evaluations of training adequacy will be critical to enable HCW to reliably administer a brief diagnostic tool for HAD.

  17. Resources, Environment, and Population: The Nature of Future Limits. Population Bulletin, Vol. 34, No. 3, August 1979.

    Science.gov (United States)

    Ridker, Ronald G.; Cecelski, Elizabeth W.

    To determine the current status and possible trends in the balance between global population growth and natural resources, the bulletin examines demands presented by population and economic growth at various periods throughout history. Periods examined are the recent past, the present to the year 2025, and the long term. Factors focused upon…

  18. Extreme events in multilayer, interdependent complex networks and control

    Science.gov (United States)

    Chen, Yu-Zhong; Huang, Zi-Gang; Zhang, Hai-Feng; Eisenberg, Daniel; Seager, Thomas P.; Lai, Ying-Cheng

    2015-11-01

    We investigate the emergence of extreme events in interdependent networks. We introduce an inter-layer traffic resource competing mechanism to account for the limited capacity associated with distinct network layers. A striking finding is that, when the number of network layers and/or the overlap among the layers are increased, extreme events can emerge in a cascading manner on a global scale. Asymptotically, there are two stable absorption states: a state free of extreme events and a state of full of extreme events, and the transition between them is abrupt. Our results indicate that internal interactions in the multiplex system can yield qualitatively distinct phenomena associated with extreme events that do not occur for independent network layers. An implication is that, e.g., public resource competitions among different service providers can lead to a higher resource requirement than naively expected. We derive an analytical theory to understand the emergence of global-scale extreme events based on the concept of effective betweenness. We also articulate a cost-effective control scheme through increasing the capacity of very few hubs to suppress the cascading process of extreme events so as to protect the entire multi-layer infrastructure against global-scale breakdown.

  19. “The Effects of Limited Resources and Opportunities on Women’s Careers in Physics: Results from the Global Survey of Physicists

    CERN Document Server

    CERN. Geneva

    2012-01-01

    The results of the Global Survey of Physicists draw attention to the need to focus on factors other than representation when discussing the situation of women in physics. Previous studies of women in physics have mostly focused on the lack of women in the field. This study goes beyond the obvious shortage of women and shows that there are much deeper issues. For the first time, a multinational study was conducted with 15000 respondents from 130 countries, showing that problems for women in physics transcend national borders. Across all countries, women have fewer resources and opportunities and are more affected by cultural expectations concerning child care. We show that limited resources and opportunities hurt career progress, and because women have fewer opportunities and resources, their careers progress more slowly. We also show the disproportionate effects of children on women physicists' careers. Cultural expectations about home and family are difficult to change. However, for women to have successful ...

  20. Evidence-based medicine for all: what we can learn from a programme providing free access to an online clinical resource to health workers in resource-limited settings.

    Science.gov (United States)

    Valtis, Yannis K; Rosenberg, Julie; Bhandari, Sudip; Wachter, Keri; Teichman, Marie; Beauvais, Sophie; Weintraub, Rebecca

    2016-01-01

    The rapidly changing landscape of medical knowledge and guidelines requires health professionals to have immediate access to current, reliable clinical resources. Access to evidence is instrumental in reducing diagnostic errors and generating better health outcomes. UpToDate, a leading evidence-based clinical resource is used extensively in the USA and other regions of the world and has been linked to lower mortality and length of stay in US hospitals. In 2009, the Global Health Delivery Project collaborated with UpToDate to provide free subscriptions to qualifying health workers in resource-limited settings. We evaluated the provision of UpToDate access to health workers by analysing their usage patterns. Since 2009, ∼2000 individual physicians and healthcare institutions from 116 countries have received free access to UpToDate through our programme. During 2013-2014, users logged into UpToDate ∼150 000 times; 61% of users logged in at least weekly; users in Africa were responsible for 54% of the total usage. Search patterns reflected local epidemiology with 'clinical manifestations of malaria' as the top search in Africa, and 'management of hepatitis B' as the top search in Asia. Our programme demonstrates that there are barriers to evidence-based clinical knowledge in resource-limited settings we can help remove. Some assumed barriers to its expansion (poor internet connectivity, lack of training and infrastructure) might pose less of a burden than subscription fees.

  1. What are the minimum requirements for ketogenic diet services in resource-limited regions? Recommendations from the International League Against Epilepsy Task Force for Dietary Therapy.

    Science.gov (United States)

    Kossoff, Eric H; Al-Macki, Nabil; Cervenka, Mackenzie C; Kim, Heung D; Liao, Jianxiang; Megaw, Katherine; Nathan, Janak K; Raimann, Ximena; Rivera, Rocio; Wiemer-Kruel, Adelheid; Williams, Emma; Zupec-Kania, Beth A

    2015-09-01

    Despite the increasing use of dietary therapies for children and adults with refractory epilepsy, the availability of these treatments in developing countries with limited resources remains suboptimal. One possible contributory factor may be the costs. There is often reported a significant perceived need for a large ketogenic diet team, supplements, laboratory studies, and follow-up visits to provide this treatment. The 2009 Epilepsia Consensus Statement described ideal requirements for a ketogenic diet center, but in some situations this is not feasible. As a result, the International League Against Epilepsy (ILAE) Task Force on Dietary Therapy was asked to convene and provide practical, cost-effective recommendations for new ketogenic diet centers in resource-limited regions of the world.

  2. Bottom-up resource limitation: the ecosystem energy balance predicts the quality of nutrition in a herbivore prey population

    DEFF Research Database (Denmark)

    Fernandez, Nestor; Garcia, Monica; Gil, Esperanza;

    2014-01-01

    Vegetation greenness indices from remote sensing are increasingly used in population ecology studies assuming that land surface reflectance can reflect the availability of nutritional resources for primary consumers. However, the relationship between these indices and the characteristics of the h......Vegetation greenness indices from remote sensing are increasingly used in population ecology studies assuming that land surface reflectance can reflect the availability of nutritional resources for primary consumers. However, the relationship between these indices and the characteristics...... of the Enhanced Vegetation Index (EVI) and two remote sensing vegetation stress indicators: the Temperature Difference Vegetation Index (TVDI) and a latent heat flux index (Hr) calculated from the dynamics of surface temperature at each site. Generalized mixed models showed that temperature indices significantly...

  3. Seeing Beyond Service - Redefining the Problem of Water and Sanitation Service Delivery in Resource-Limited Settings to Enable Effective Solutions

    OpenAIRE

    Strock, Christopher Moore

    2010-01-01

    The purpose of this study was to examine the effectiveness of water and sanitation service delivery in resource-limited settings using two different social theories (modernization and world system). Understanding that barriers to effectiveness are rooted in global structures that tend to present at local levels helps redefine the problem leading to comprehensive policies and practices. The guiding research questions included an identification of an effectiveness gap in services delivered in d...

  4. Perceptions regarding menstruation and Practices during menstrual cycles among high school going adolescent girls in resource limited settings around Bangalore city, Karnataka, India

    OpenAIRE

    Shanbhag D; Shilpa R; D’Souza N; Josephine P; Singh J; Goud BR

    2012-01-01

    Introduction: Hygiene-related practices of adolescents during menstruation are of importance, as it has a health impact in terms of increased vulnerability to reproductive tract infections (RTI). Therefore, increased knowledge about menstruation right from childhood may escalate safe practices and may help in mitigating the suffering of women.Objectives: To assess the perceptions and practices regarding menstrual hygiene among selected high school girls in a resource limited settings in area ...

  5. Risk assessment of precipitation extremes in northern Xinjiang, China

    Science.gov (United States)

    Yang, Jun; Pei, Ying; Zhang, Yanwei; Ge, Quansheng

    2017-04-01

    This study was conducted using daily precipitation records gathered at 37 meteorological stations in northern Xinjiang, China, from 1961 to 2010. We used the extreme value theory model, generalized extreme value (GEV) and generalized Pareto distribution (GPD), statistical distribution function to fit outputs of precipitation extremes with different return periods to estimate risks of precipitation extremes and diagnose aridity-humidity environmental variation and corresponding spatial patterns in northern Xinjiang. Spatiotemporal patterns of daily maximum precipitation showed that aridity-humidity conditions of northern Xinjiang could be well represented by the return periods of the precipitation data. Indices of daily maximum precipitation were effective in the prediction of floods in the study area. By analyzing future projections of daily maximum precipitation (2, 5, 10, 30, 50, and 100 years), we conclude that the flood risk will gradually increase in northern Xinjiang. GEV extreme value modeling yielded the best results, proving to be extremely valuable. Through example analysis for extreme precipitation models, the GEV statistical model was superior in terms of favorable analog extreme precipitation. The GPD model calculation results reflect annual precipitation. For most of the estimated sites' 2 and 5-year T for precipitation levels, GPD results were slightly greater than GEV results. The study found that extreme precipitation reaching a certain limit value level will cause a flood disaster. Therefore, predicting future extreme precipitation may aid warnings of flood disaster. A suitable policy concerning effective water resource management is thus urgently required.

  6. Infection prevention and control strategies in the era of limited resources and quality improvement: a perspective paper.

    Science.gov (United States)

    Vandijck, Dominique; Cleemput, Irina; Hellings, Johan; Vogelaers, Dirk

    2013-11-01

    This paper aims to describe, using an evidence-based approach, the importance of and the resources necessary for implementing effective infection prevention and control (IPC) programmes. The intrinsic and explicit values of such strategies are presented from a clinical, health-economic and patient safety perspective. Policy makers and hospital managers are committed to providing comprehensive, accessible, and affordable healthcare of high quality. Changes in the healthcare system over time accompanied with variations in demographics and case-mix have considerably affected the availability, quality and ultimately the safety of healthcare. The main goal of an IPC programme is to prevent and control healthcare-associated infections (HAI). Many patient-, healthcare provider-, and organizational factors are associated with an increased risk for acquiring HAIs and may impact both the quality and outcome of patient care. Evidence has been published in support of having an effective IPC programme. It has been estimated that about one-third of HAIs could be prevented if key elements of the evidence-based recommendations for IPC are adequately introduced and followed. However, several healthcare agencies from over the world have reported deficits in the essential resources and components of current IPC programmes. To meet its main goal, staffing, training, and infrastructure requirements are needed. Nevertheless, and given the economic crisis, policy makers and hospital managers may be tempted to not increase or even to reduce the budget as it consumes resources and does not generate sufficient visible revenue. IPC is a critical issue in patient safety, as HAIs are by far the most common complication affecting admitted patients. The significant clinical and health-economic burden HAIs place on the healthcare system speak to the importance of getting introduced effective IPC programmes.

  7. Allocating limited resources in a time of fiscal constraints: a priority setting case study from Dalhousie University Faculty of Medicine.

    Science.gov (United States)

    Mitton, Craig; Levy, Adrian; Gorsky, Diane; MacNeil, Christina; Dionne, Francois; Marrie, Tom

    2013-07-01

    Facing a projected $1.4M deficit on a $35M operating budget for fiscal year 2011/2012, members of the Dalhousie University Faculty of Medicine developed and implemented an explicit, transparent, criteria-based priority setting process for resource reallocation. A task group that included representatives from across the Faculty of Medicine used a program budgeting and marginal analysis (PBMA) framework, which provided an alternative to the typical public-sector approaches to addressing a budget deficit of across-the-board spending cuts and political negotiation. Key steps to the PBMA process included training staff members and department heads on priority setting and resource reallocation, establishing process guidelines to meet immediate and longer-term fiscal needs, developing a reporting structure and forming key working groups, creating assessment criteria to guide resource reallocation decisions, assessing disinvestment proposals from all departments, and providing proposal implementation recommendations to the dean. All departments were required to submit proposals for consideration. The task group approved 27 service reduction proposals and 28 efficiency gains proposals, totaling approximately $2.7M in savings across two years. During this process, the task group faced a number of challenges, including a tight timeline for development and implementation (January to April 2011), a culture that historically supported decentralized planning, at times competing interests (e.g., research versus teaching objectives), and reductions in overall health care and postsecondary education government funding. Overall, faculty and staff preferred the PBMA approach to previous practices. Other institutions should use this example to set priorities in times of fiscal constraints.

  8. Multi-Agent Coordination and Cooperation in a Distributed Dynamic Environment with Limited Resources: Simulated Air Wars

    Science.gov (United States)

    1993-11-01

    of agents [Lo, 1988; Parunak, 1987; Smith , 1980; Smith & Davis, 1981]. 2.1.2 Coordination Closely related to cooperation, coordination involves the...even compete with one another. One of the earliest, and perhaps best known, DAI coordination techniques is the contract net [Davis & Smith , 1983; Smith ...Aircraft Resources A/C Combat Factor Maximum Engagements Z=x A-toA A-to-G Enurance SedrA A-toA A-to-G F-01 5 0 3 8 3 0 F-02 10 0 4 8 3 0 F-03 15 0 5 10

  9. Summary of resources available to small water systems for meeting the 10 ppb arsenic drinking water limit.

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James Lee; Thomson, Bruce M. (University of New Mexico, Albuquerque, NM); Ziegler, Matt (New Mexico Tech, Albuquerque, NM); Butler, Susan (New Mexico Tech, Albuquerque, NM); Himmelberger, Heather (New Mexico Tech, Albuquerque, NM); Holt, Kathleen Caroline

    2007-01-01

    With the lowering of the EPA maximum contaminant level of arsenic from 50 parts per billion (ppb) to 10 ppb, many public water systems in the country and in New Mexico in particular, are faced with making decisions about how to bring their system into compliance. This document provides detail on the options available to the water systems and the steps they need to take to achieve compliance with this regulation. Additionally, this document provides extensive resources and reference information for additional outreach support, financing options, vendors for treatment systems, and media pilot project results.

  10. Food composition tables in resource-poor settings: exploring current limitations and opportunities, with a focus on animal-source foods in sub-Saharan Africa.

    Science.gov (United States)

    de Bruyn, Julia; Ferguson, Elaine; Allman-Farinelli, Margaret; Darnton-Hill, Ian; Maulaga, Wende; Msuya, John; Alders, Robyn

    2016-11-08

    Animal-source foods (ASF) have the potential to enhance the nutritional adequacy of cereal-based diets in low- and middle-income countries, through the provision of high-quality protein and bioavailable micronutrients. The development of guidelines for including ASF in local diets requires an understanding of the nutrient content of available resources. This article reviews food composition tables (FCT) used in sub-Saharan Africa, examining the spectrum of ASF reported and exploring data sources for each reference. Compositional data are shown to be derived from a small number of existing data sets from analyses conducted largely in high-income nations, often many decades previously. There are limitations in using such values, which represent the products of intensively raised animals of commercial breeds, as a reference in resource-poor settings where indigenous breed livestock are commonly reared in low-input production systems, on mineral-deficient soils and not receiving nutritionally balanced feed. The FCT examined also revealed a lack of data on the full spectrum of ASF, including offal and wild foods, which correspond to local food preferences and represent valuable dietary resources in food-deficient settings. Using poultry products as an example, comparisons are made between compositional data from three high-income nations, and potential implications of differences in the published values for micronutrients of public health significance, including Fe, folate and vitamin A, are discussed. It is important that those working on nutritional interventions and on developing dietary recommendations for resource-poor settings understand the limitations of current food composition data and that opportunities to improve existing resources are more actively explored and supported.

  11. A Systematic Review of Economic Evaluation Methodologies Between Resource-Limited and Resource-Rich Countries: A Case of Rotavirus Vaccines.

    Science.gov (United States)

    Thiboonboon, Kittiphong; Santatiwongchai, Benjarin; Chantarastapornchit, Varit; Rattanavipapong, Waranya; Teerawattananon, Yot

    2016-12-01

    For more than three decades, the number and influence of economic evaluations of healthcare interventions have been increasing and gaining attention from a policy level. However, concerns about the credibility of these studies exist, particularly in studies from low- and middle- income countries (LMICs). This analysis was performed to explore economic evaluations conducted in LMICs in terms of methodological variations, quality of reporting and evidence used for the analyses. These results were compared with those studies conducted in high-income countries (HICs). Rotavirus vaccine was selected as a case study, as it is one of the interventions that many studies in both settings have explored. The search to identify individual studies on rotavirus vaccines was performed in March 2014 using MEDLINE and the National Health Service Economic Evaluation Database. Only full economic evaluations, comparing cost and outcomes of at least two alternatives, were included for review. Selected criteria were applied to assess methodological variation, quality of reporting and quality of evidence used. Eighty-five studies were included, consisting of 45 studies in HICs and 40 studies in LMICs. Seventy-five percent of the studies in LMICs were published by researchers from HICs. Compared with studies in HICs, the LMIC studies showed less methodological variety. In terms of the quality of reporting, LMICs had a high adherence to technical criteria, but HICs ultimately proved to be better. The same trend applied for the quality of evidence used. Although the quality of economic evaluations in LMICs was not as high as those from HICs, it is of an acceptable level given several limitations that exist in these settings. However, the results of this study may not reflect the fact that LMICs have developed a better research capacity in the domain of health economics, given that most of the studies were in theory led by researchers from HICs. Putting more effort into fostering the

  12. The limits of human endurance: what is the greatest endurance performance of all time? Which factors regulate performance at extreme altitude?

    Science.gov (United States)

    Noakes, Timothy David

    2007-01-01

    Humans evolved as an athletic species able to run in the midday heat, to throw with exquisite accuracy and to strike powerfully despite relatively weak upper arms compared to those of the great apes. The true extent to which humans could run long distances was first tested in a unique series of 6-day foot races contested between 1874 and 1888 by professional athletes from England and the United States. These athletes typically would have expended approximately 60,000 kcal (24.12 MJ) of energy during these races. The discovery of the bicycle soon caused the replacement of these races by 6-day cycling races which, in turn, led to the modern day Tour de France, the cycling race across America (RaAM) and two running races across the width of the United States in 1928 and 1929. The total energy expenditures during these different events can be estimated at approximately 168,000, 180,000 and 340,000 kcal respectively. But, in terms of the total energy expenditure, all these performances pale somewhat when compared to that of Robert Falcon Scott's Polar party during the 1911/12 British Antarctic Expedition. For most of 159 consecutive days, Scott's team man-hauled for 10 hours a day to the South Pole and back covering a distance of 2500 km. Their predicted total energy expenditure per individual would have been about 1 million kcal, making theirs, by some margin, the greatest sustained endurance athletic performance of all time. Interestingly, the dogs that provided the pulling power for Norwegian Roald Amundsen's team that was the first to reach the South Pole, 35 days before Scott's party, would have expended about 500,000 kcal in their 97 day trip, making theirs the greatest animal "sporting" performance on record. By contrast, mountain climbers expend only approximately 4000 kcal/day when climbing at extreme altitudes (above 4000 m). This relatively low rate of energy expenditure results from the low exercise intensities that can be sustained at extreme altitude. Here

  13. Rapid CD4 decline after interruption of non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    Watcharananan Siriorn

    2007-11-01

    Full Text Available Abstract Background Non-nucleoside reverse transcriptase inhibitor (NNRTI with stavudine and lamivudine is widely used as the first-line antiretroviral therapy (ART in resource-limited settings. Lipodystrophy is common and options for switching ART regimen are limited; this situation can lead to patients' poor adherence and antiretroviral resistance. Treatment interruption (TI in patients with high CD4 cell counts, lipodystrophy, and limited options may be an alternative in resource-limited settings. This study aimed to determine time to resume ART after TI and predictors for early resumption of ART in a resource-limited setting. Methods A prospective study was conducted in January 2005 to December 2006 and enrolled HIV-infected patients with HIV-1 RNA 350 cells/mm3, and willing to interrupt ART. CD4 cell count, HIV-1 RNA, lipid profile, and lipodystrophy were assessed at baseline and every 3 months. ART was resumed when CD4 declined to 3 or developed HIV-related symptoms. Patients were grouped based on ART regimens [NNRTI or protease inhibitor (PI] prior to TI. Results There were 99 patients, 85 in NNRTI group and 14 in PI group. Mean age was 40.6 years; 46% were males. Median duration of ART was 47 months. Median nadir CD4 and baseline CD4 were 151 and 535 cells/mm3, respectively. Median CD4 change at 3 months after TI were -259 (NNRTI and -105 (PI cells/mm3 (p = 0.038. At 13-month median follow-up, there was no AIDS-defining illness; 38% (NNRTI and 29% (PI of patients developed HIV-related symptoms. ART was resumed in 51% (NNRTI and 36% (PI of patients (p = 0.022. By Kaplan-Meier analysis, median time to resume ART was 5.5 (NNRTI and 14.2 (PI months (log rank test, p = 0.026. By Cox's regression analysis, NNRTI-based ART (HR 4.9; 95%CI, 1.5–16.3, nadir CD4 3 (HR 2.7; 95%CI 1.4–5.3 and baseline CD4 3 (HR 1.6; 95%CI, 1.2–3.1 were predictors for early ART resumption. Conclusion TI of NNRTI-based ART leads to rapid CD4 decline and high

  14. Integrative Review of the Literature on Adults with Limited Education and Skills and the Implications for Human Resource Development

    Science.gov (United States)

    Hamilton, David W.; Torraco, Richard J.

    2013-01-01

    Adults with limited education and skills--those who lack the education and skills needed for full participation in U.S. culture and economy--are increasing in numbers. However, the knowledge base addressing this population and their educational needs is fragmented across the literature of several disciplines. A comprehensive review and critique of…

  15. Integrative Review of the Literature on Adults with Limited Education and Skills and the Implications for Human Resource Development

    Science.gov (United States)

    Hamilton, David W.; Torraco, Richard J.

    2013-01-01

    Adults with limited education and skills--those who lack the education and skills needed for full participation in U.S. culture and economy--are increasing in numbers. However, the knowledge base addressing this population and their educational needs is fragmented across the literature of several disciplines. A comprehensive review and critique of…

  16. Exacerbations and health care resource utilization in patients with airflow limitation diseases attending a primary care setting: the PUMA study

    Science.gov (United States)

    Montes de Oca, Maria; Aguirre, Carlos; Lopez Varela, Maria Victorina; Laucho-Contreras, Maria E; Casas, Alejandro; Surmont, Filip

    2016-01-01

    Background COPD, asthma, and asthma–COPD overlap increase health care resource consumption, predominantly because of hospitalization for exacerbations and also increased visits to general practitioners (GPs) or specialists. Little information is available regarding this in the primary care setting. Objectives To describe the prevalence and number of GP and specialist visits for any cause or due to exacerbations in patients with COPD, asthma, and asthma–COPD overlap. Methods COPD was defined as post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio <0.70; asthma was defined as prior medical diagnosis, wheezing in the last 12 months, or wheezing plus reversibility (post-bronchodilator FEV1 or FVC increase ≥200 mL and ≥12%); asthma–COPD overlap was defined as post-bronchodilator FEV1/FVC <0.70 plus prior asthma diagnosis. Health care utilization was evaluated as GP and/or specialist visits in the previous year. Results Among the 1,743 individuals who completed the questionnaire, 1,540 performed acceptable spirometry. COPD patients had a higher prevalence of any medical visits to any physician versus those without COPD (37.2% vs 21.8%, respectively) and exacerbations doubled the number of visits. The prevalence of any medical visits to any physician was also higher in asthma patients versus those without asthma (wheezing: 47.2% vs 22.7%; medical diagnosis: 54.6% vs 21.6%; wheezing plus reversibility: 46.2% vs 23.8%, respectively). Asthma patients with exacerbations had twice the number of visits versus those without an exacerbation. The number of visits was higher (2.8 times) in asthma–COPD overlap, asthma (1.9 times), or COPD (1.4 times) patients versus those without these respiratory diseases; the number of visits due to exacerbation was also higher (4.9 times) in asthma–COPD overlap, asthma (3.5 times), and COPD (3.8 times) patients. Conclusion COPD, asthma, and asthma–COPD overlap increase the prevalence of

  17. Exacerbations and health care resource utilization in patients with airflow limitation diseases attending a primary care setting: the PUMA study

    Directory of Open Access Journals (Sweden)

    Montes de Oca M

    2016-12-01

    Full Text Available Maria Montes de Oca,1 Carlos Aguirre,2 Maria Victorina Lopez Varela,3 Maria E Laucho-Contreras,1 Alejandro Casas,2 Filip Surmont4 1Service of Pneumology, Hospital Universitario de Caracas, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela; 2Colombian Pneumological Foundation, Bogotá, Colombia; 3Universidad de la República, Facultad de Medicina, Hospital Maciel, Montevideo, Uruguay; 4Medical Affairs, AstraZeneca Latin America, Coral Gables, FL, USA Background: COPD, asthma, and asthma–COPD overlap increase health care resource consumption, predominantly because of hospitalization for exacerbations and also increased visits to general practitioners (GPs or specialists. Little information is available regarding this in the primary care setting. Objectives: To describe the prevalence and number of GP and specialist visits for any cause or due to exacerbations in patients with COPD, asthma, and asthma–COPD overlap. Methods: COPD was defined as post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC ratio <0.70; asthma was defined as prior medical diagnosis, wheezing in the last 12 months, or wheezing plus reversibility (post-bronchodilator FEV1 or FVC increase ≥200 mL and ≥12%; asthma–COPD overlap was defined as post-bronchodilator FEV1/FVC <0.70 plus prior asthma diagnosis. Health care utilization was evaluated as GP and/or specialist visits in the previous year. Results: Among the 1,743 individuals who completed the questionnaire, 1,540 performed acceptable spirometry. COPD patients had a higher prevalence of any medical visits to any physician versus those without COPD (37.2% vs 21.8%, respectively and exacerbations doubled the number of visits. The prevalence of any medical visits to any physician was also higher in asthma patients versus those without asthma (wheezing: 47.2% vs 22.7%; medical diagnosis: 54.6% vs 21.6%; wheezing plus reversibility: 46.2% vs 23.8%, respectively

  18. Evaluation of an educational program for essential newborn care in resource-limited settings: Essential Care for Every Baby.

    Science.gov (United States)

    Thukral, Anu; Lockyer, Jocelyn; Bucher, Sherri L; Berkelhamer, Sara; Bose, Carl; Deorari, Ashok; Esamai, Fabian; Faremo, Sonia; Keenan, William J; McMillan, Douglas; Niermeyer, Susan; Singhal, Nalini

    2015-06-24

    Essential Care for Every Baby (ECEB) is an evidence-based educational program designed to increase cognitive knowledge and develop skills of health care professionals in essential newborn care in low-resource areas. The course focuses on the immediate care of the newborn after birth and during the first day or until discharge from the health facility. This study assessed the overall design of the course; the ability of facilitators to teach the course; and the knowledge and skills acquired by the learners. Testing occurred at 2 global sites. Data from a facilitator evaluation survey, a learner satisfaction survey, a multiple choice question (MCQ) examination, performance on two objective structured clinical evaluations (OSCE), and pre- and post-course confidence assessments were analyzed using descriptive statistics. Pre-post course differences were examined. Comments on the evaluation form and post-course group discussions were analyzed to identify potential program improvements. Using ECEB course material, master trainers taught 12 facilitators in India and 11 in Kenya who subsequently taught 62 providers of newborn care in India and 64 in Kenya. Facilitators and learners were satisfied with their ability to teach and learn from the program. Confidence (3.5 to 5) and MCQ scores (India: pre 19.4, post 24.8; Kenya: pre 20.8, post 25.0) improved (p < 0.001). Most participants demonstrated satisfactory skills on the OSCEs. Qualitative data suggested the course was effective, but also identified areas for course improvement. These included additional time for hands-on practice, including practice in a clinical setting, the addition of video learning aids and the adaptation of content to conform to locally recommended practices. ECEB program was highly acceptable, demonstrated improved confidence, improved knowledge and developed skills. ECEB may improve newborn care in low resource settings if it is part of an overall implementation plan that addresses local needs and

  19. Nucleating the development of telemedicine to support healthcare workers in resource-limited settings: a new approach.

    Science.gov (United States)

    Wootton, Richard; Wu, Wei-I; Bonnardot, Laurent

    2013-10-01

    Collegium Telemedicus (CT) offers a new approach to the problem of starting a store-and-forward telemedicine network for use in low resource settings. The CT organization provides a no-cost template to allow groups to start a network without delay, together with a peer-support environment for those operating the networks. A new group needs only to supply a Guarantor (who accepts responsibility for the work of the network) and a Coordinator (who operates the telemedicine network, allocating cases and ensuring that they are responded to). Communication takes place via secure messaging, which has several advantages over plain email, e.g. all the data are stored centrally, which means that they can be read from a hand-held device such as a smart phone, but do not need to be stored on that device. Users can access the system with a standard web browser. In the first three months, seven networks were established on the CT system by university groups in the US, the UK, Australia and New Zealand, and by a large, multinational humanitarian organisation. In the most active network, there were 86 telemedicine cases in the first three months, i.e. an average submission rate of 7 cases/week. The CT system appears to fulfil its aim of assisting doctors who wish to help colleagues in other countries by improving their access to specialist opinions, while allowing them to maintain control over the new network's use and development. The long term aim of the CT organization is to provide a means of improving the quality of health care at the point of delivery in low resource settings.

  20. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W;

    2016-01-01

    This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing...... and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  1. Extremal surface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, Netta; Wall, Aron C. [Department of Physics, University of California,Santa Barbara, CA 93106 (United States)

    2014-03-13

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy.

  2. Approaches for scaling up human immunodeficiency virus testing and counseling in prevention of mother-to-child human immunodeficiency virus transmission settings in resource-limited countries.

    Science.gov (United States)

    Bolu, Omotayo O; Allread, Virginia; Creek, Tracy; Stringer, Elizabeth; Forna, Fatu; Bulterys, Marc; Shaffer, Nathan

    2007-09-01

    Prevention of mother-to-child human immunodeficiency virus (HIV) transmission (PMTCT) programs have nearly eliminated mother-to-child transmission of HIV in developed countries, but progress in resource-limited countries has been slow. A key factor limiting the scale-up of PMTCT programs is lack of knowledge of HIV serostatus. Increasing the availability and acceptability of HIV testing and counseling services will encourage more women to learn their status, providing a gateway to PMTCT interventions. Key factors contributing to the scale-up of testing and counseling include a policy of provider-initiated testing and counseling with right to refuse (opt-out); group pretest counseling; rapid HIV testing; innovative staffing strategies; and community and male involvement. Integration of testing and counseling within the community and all maternal and child health settings are critical for scaling-up and for linking women and their families to care and treatment services. This paper will review best practices needed for expansion of testing and counseling in PMTCT settings in resource-limited countries.

  3. A series of meta-analytic tests of the depletion effect: Self-control does not seem to rely on a limited resource.

    Science.gov (United States)

    Carter, Evan C; Kofler, Lilly M; Forster, Daniel E; McCullough, Michael E

    2015-08-01

    Failures of self-control are thought to underlie various important behaviors (e.g., addiction, violence, obesity, poor academic achievement). The modern conceptualization of self-control failure has been heavily influenced by the idea that self-control functions as if it relied upon a limited physiological or cognitive resource. This view of self-control has inspired hundreds of experiments designed to test the prediction that acts of self-control are more likely to fail when they follow previous acts of self-control (the depletion effect). Here, we evaluated the empirical evidence for this effect with a series of focused, meta-analytic tests that address the limitations in prior appraisals of the evidence. We find very little evidence that the depletion effect is a real phenomenon, at least when assessed with the methods most frequently used in the laboratory. Our results strongly challenge the idea that self-control functions as if it relies on a limited psychological or physical resource. (c) 2015 APA, all rights reserved).

  4. Simplification of antiretroviral therapy: a necessary step in the public health response to HIV/AIDS in resource-limited settings.

    Science.gov (United States)

    Vitoria, Marco; Ford, Nathan; Doherty, Meg; Flexner, Charles

    2014-01-01

    The global scale-up of antiretroviral therapy (ART) over the past decade represents one of the great public health and human rights achievements of recent times. Moving from an individualized treatment approach to a simplified and standardized public health approach has been critical to ART scale-up, simplifying both prescribing practices and supply chain management. In terms of the latter, the risk of stock-outs can be reduced and simplified prescribing practices support task shifting of care to nursing and other non-physician clinicians; this strategy is critical to increase access to ART care in settings where physicians are limited in number. In order to support such simplification, successive World Health Organization guidelines for ART in resource-limited settings have aimed to reduce the number of recommended options for first-line ART in such settings. Future drug and regimen choices for resource-limited settings will likely be guided by the same principles that have led to the recommendation of a single preferred regimen and will favour drugs that have the following characteristics: minimal risk of failure, efficacy and tolerability, robustness and forgiveness, no overlapping resistance in treatment sequencing, convenience, affordability, and compatibility with anti-TB and anti-hepatitis treatments.

  5. Development of a technical assistance framework for building organizational capacity of health programs in resource-limited settings.

    Science.gov (United States)

    Reyes, E Michael; Sharma, Anjali; Thomas, Kate K; Kuehn, Chuck; Morales, José Rafael

    2014-09-17

    Little information exists on the technical assistance needs of local indigenous organizations charged with managing HIV care and treatment programs funded by the US President's Emergency Plan for AIDS Relief (PEPFAR). This paper describes the methods used to adapt the Primary Care Assessment Tool (PCAT) framework, which has successfully strengthened HIV primary care services in the US, into one that could strengthen the capacity of local partners to deliver priority health programs in resource-constrained settings by identifying their specific technical assistance needs. Qualitative methods and inductive reasoning approaches were used to conceptualize and adapt the new Clinical Assessment for Systems Strengthening (ClASS) framework. Stakeholder interviews, comparisons of existing assessment tools, and a pilot test helped determine the overall ClASS framework for use in low-resource settings. The framework was further refined one year post-ClASS implementation. Stakeholder interviews, assessment of existing tools, a pilot process and the one-year post- implementation assessment informed the adaptation of the ClASS framework for assessing and strengthening technical and managerial capacities of health programs at three levels: international partner, local indigenous partner, and local partner treatment facility. The PCAT focus on organizational strengths and systems strengthening was retained and implemented in the ClASS framework and approach. A modular format was chosen to allow the use of administrative, fiscal and clinical modules in any combination and to insert new modules as needed by programs. The pilot led to refined pre-visit planning, informed review team composition, increased visit duration, and restructured modules. A web-based toolkit was developed to capture three years of experiential learning; this kit can also be used for independent implementation of the ClASS framework. A systematic adaptation process has produced a qualitative framework that can

  6. Extreme cosmos

    CERN Document Server

    Gaensler, Bryan

    2011-01-01

    The universe is all about extremes. Space has a temperature 270°C below freezing. Stars die in catastrophic supernova explosions a billion times brighter than the Sun. A black hole can generate 10 million trillion volts of electricity. And hypergiants are stars 2 billion kilometres across, larger than the orbit of Jupiter. Extreme Cosmos provides a stunning new view of the way the Universe works, seen through the lens of extremes: the fastest, hottest, heaviest, brightest, oldest, densest and even the loudest. This is an astronomy book that not only offers amazing facts and figures but also re

  7. Extreme patterns of variance in small populations: placing limits on human Y-chromosome diversity through time in the Vanuatu Archipelago.

    Science.gov (United States)

    Cox, M

    2007-05-01

    Small populations are dominated by unique patterns of variance, largely characterized by rapid drift of allele frequencies. Although the variance components of genetic datasets have long been recognized, most population genetic studies still treat all sampling locations equally despite differences in sampling and effective population sizes. Because excluding the effects of variance can lead to significant biases in historical reconstruction, variance components should be incorporated explicitly into population genetic analyses. The possible magnitude of variance effects in small populations is illustrated here via a case study of Y-chromosome haplogroup diversity in the Vanuatu Archipelago. Deme-based modelling is used to simulate allele frequencies through time, and conservative confidence bounds are placed on the accumulation of stochastic variance effects, including diachronic genetic drift and contemporary sampling error. When the information content of the dataset has been ascertained, demographic models with parameters falling outside the confidence bounds of the variance components can then be accepted with some statistical confidence. Here I emphasize how aspects of the demographic history of a population can be disentangled from stochastic variance effects, and I illustrate the extreme roles of genetic drift and sampling error for many small human population datasets.

  8. Quantification of print, radio and television exposure among previous blood donors in Kenya: an opportunity for encouraging repeat donation in a resource-limited setting?

    Science.gov (United States)

    Basavaraju, S V; Mwangi, J; Kellogg, T A; Odawo, L; Marum, L H

    2010-10-01

    Blood services in sub-Saharan Africa experience blood shortages and low retention of voluntary, non-remunerated donors. To boost collections by encouraging repeat donations, the Kenya National Blood Transfusion Service is exploring the likelihood of reaching previous donors through targeted print, radio and television advertising. We analysed data from a national AIDS Indicator Survey to determine whether previous donors have significant exposure to media. Respondents reporting history of blood donation had significantly higher exposure to print, radio and television media than those without history of blood donation. Targeted media campaigns encouraging repeat donation are likely to reach previous donors even in resource-limited settings.

  9. State and Civil Society in the search of resources for overcoming xenophobia, nationalism and extremism in Russia in the contemporary period

    Directory of Open Access Journals (Sweden)

    Pankratov Sergey Anatolievich

    2013-02-01

    Full Text Available This article analyzes the results of the work of the Research and Education Center “Modernization of multidimensional socio-political space of contemporary Russia”. Particular attention is paid to the realization of the first stage of the state contract on the topic “Innovative resources and models of political and legal resocialization of the youth cohorts representatives that are prone to xenophobia and nationalism, extremist forms of behavior in the context of modernization of contemporary Russia”.

  10. Inter-Firm Information Sharing in Enterprise Resource Planning Systems: a call for timely but limited access to customer information

    Directory of Open Access Journals (Sweden)

    Michael Busing

    2001-11-01

    Full Text Available Current trends in Enterprise Resource Planning (ERP suggest that supply chain management and tight control over scheduling jobs within the supply chain are key tactical planning issues. Modern ERP software packages, in conjunction with the World Wide Web, allow for automated exchange of information within a company and also between two or more companies (i.e., conveyance of customer information to suppliers of parts and components for the purposes of effective planning and control. While ease of information exchange between a customer and supplier is increasingly critical to the success of modern-day planning and control efforts, the issue of information security is also a very real concern. Suppliers can benefit from gaining access to a customer's dispatch list and material requirements plan (MRP in order to determine real-time priority of jobs in queue at various work centers within their own organization. Other customer information, however, should remain secure and unavailable to supplier firms for competitive reasons such as threat of forward integration. This paper presents a previously tested priority-sequencing rule that explicitly considers downstream shop conditions in determining which job to run next The rule proves to perform well on mean flow time and lateness as well as on variability of these measures. The rule is extended here to incorporate the case where a downstream work center is outside official corporate boundaries. With the call for free exchange of information comes the threat of other, perhaps proprietary, information being accessed by vendors or others outside the official corporate boundaries. The paper will propose information that should be freely exchanged between customers and suppliers and information that should remain secure. Finally, practical measures to manage access to web-enabled ERP information will be proposed.

  11. Utilization of health services in a resource-limited rural area in Kenya: Prevalence and associated household-level factors

    Science.gov (United States)

    Ngugi, Anthony K.; Agoi, Felix; Mahoney, Megan R.; Lakhani, Amyn; Mang’ong’o, David; Nderitu, Esther; Armstrong, Robert; Macfarlane, Sarah

    2017-01-01

    Background and methods Knowledge of utilization of health services and associated factors is important in planning and delivery of interventions to improve health services coverage. We determined the prevalence and factors associated with health services utilization in a rural area of Kenya. Our findings inform the local health management in development of appropriately targeted interventions. We used a cluster sample survey design and interviewed household key informants on history of illness for household members and health services utilization in the preceding month. We estimated prevalence and performed random effects logistic regression to determine the influence of individual and household level factors on decisions to utilize health services. Results and conclusions 1230/6,440 (19.1%, 95% CI: 18.3%-20.2%) household members reported an illness. Of these, 76.7% (95% CI: 74.2%-79.0%) sought healthcare in a health facility. The majority (94%) of the respondents visited dispensary-level facilities and only 60.1% attended facilities within the study sub-counties. Of those that did not seek health services, 43% self-medicated by buying non-prescription drugs, 20% thought health services were too costly, and 10% indicated that the sickness was not serious enough to necessitate visiting a health facility. In the multivariate analyses, relationship to head of household was associated with utilization of health services. Relatives other than the nuclear family of the head of household were five times less likely to seek medical help (Odds Ratio 0.21 (95% CI: 0.05–0.87)). Dispensary level health facilities are the most commonly used by members of this community, and relations at the level of the household influence utilization of health services during an illness. These data enrich the perspective of the local health management to better plan the allocation of healthcare resources according to need and demand. The findings will also contribute in the development of

  12. Thoracic ultrasound: An adjunctive and valuable imaging tool in emergency, resource-limited settings and for a sustainable monitoring of patients

    Science.gov (United States)

    Trovato, Francesca M; Catalano, Daniela; Trovato, Guglielmo M

    2016-01-01

    Imaging workup of patients referred for elective assessment of chest disease requires an articulated approach: Imaging is asked for achieving timely diagnosis. The concurrent or subsequent use of thoracic ultrasound (TUS) with conventional (chest X-rays-) and more advanced imaging procedures (computed tomography and magnetic resonance imaging) implies advantages, limitations and actual problems. Indeed, despite TUS may provide useful imaging of pleura, lung and heart disease, emergency scenarios are currently the most warranted field of application of TUS: Pleural effusion, pneumothorax, lung consolidation. This stems from its role in limited resources subsets; actually, ultrasound is an excellent risk reducing tool, which acts by: (1) increasing diagnostic certainty; (2) shortening time to definitive therapy; and (3) decreasing problems from blind procedures that carry an inherent level of complications. In addition, paediatric and newborn disease are particularly suitable for TUS investigation, aimed at the detection of congenital or acquired chest disease avoiding, limiting or postponing radiological exposure. TUS improves the effectiveness of elective medical practice, in resource-limited settings, in small point of care facilities and particularly in poorer countries. Quality and information provided by the procedure are increased avoiding whenever possible artefacts that can prevent or mislead the achievement of the correct diagnosis. Reliable monitoring of patients is possible, taking into consideration that appropriate expertise, knowledge, skills, training, and even adequate equipment’s suitability are not always and everywhere affordable or accessible. TUS is complementary imaging procedure for the radiologist and an excellent basic diagnostic tool suitable to be shared with pneumologists, cardiologists and emergency physicians.

  13. Qualitative analysis of programmatic initiatives to text patients with mobile devices in resource-limited health systems.

    Science.gov (United States)

    Garg, Sachin K; Lyles, Courtney R; Ackerman, Sara; Handley, Margaret A; Schillinger, Dean; Gourley, Gato; Aulakh, Veenu; Sarkar, Urmimala

    2016-02-06

    Text messaging is an affordable, ubiquitous, and expanding mobile communication technology. However, safety net health systems in the United States that provide more care to uninsured and low-income patients may face additional financial and infrastructural challenges in utilizing this technology. Formative evaluations of texting implementation experiences are limited. We interviewed safety net health systems piloting texting initiatives to study facilitators and barriers to real-world implementation. We conducted telephone interviews with various stakeholders who volunteered from each of the eight California-based safety net systems that received external funding to pilot a texting-based program of their choosing to serve a primary care need. We developed a semi-structured interview guide based partly on the Consolidated Framework for Implementation Research (CFIR), which encompasses several domains: the intervention, individuals involved, contextual factors, and implementation process. We inductively and deductively (using CFIR) coded transcripts, and categorized themes into facilitators and barriers. We performed eight interviews (one interview per pilot site). Five sites had no prior texting experience. Sites applied texting for programs related to medication adherence and monitoring, appointment reminders, care coordination, and health education and promotion. No site texted patient-identifying health information, and most sites manually obtained informed consent from each participating patient. Facilitators of implementation included perceived enthusiasm from patients, staff and management belief that texting is patient-centered, and the early identification of potential barriers through peer collaboration among grantees. Navigating government regulations that protect patient privacy and guide the handling of protected health information emerged as a crucial barrier. A related technical challenge in five sites was the labor-intensive tracking and documenting

  14. Smart cloud system with image processing server in diagnosing brain diseases dedicated for hospitals with limited resources.

    Science.gov (United States)

    Fahmi, Fahmi; Nasution, Tigor H

    2017-01-19

    The use of medical imaging in diagnosing brain disease is growing. The challenges are related to the big size of data and complexity of the image processing. High standard of hardware and software are demanded, which can only be provided in big hospitals. Our purpose was to provide a smart cloud system to help diagnosing brain diseases for hospital with limited infrastructure. The expertise of neurologists was first implanted in cloud server to conduct an automatic diagnosis in real time using image processing technique developed based on ITK library and web service. Users upload images through website and the result, in this case the size of tumor was sent back immediately. A specific image compression technique was developed for this purpose. The smart cloud system was able to measure the area and location of tumors, with average size of 19.91 ± 2.38 cm2 and an average response time 7.0 ± 0.3 s. The capability of the server decreased when multiple clients accessed the system simultaneously: 14 ± 0 s (5 parallel clients) and 27 ± 0.2 s (10 parallel clients). The cloud system was successfully developed to process and analyze medical images for diagnosing brain diseases in this case for tumor.

  15. Increasing access to kidney transplantation in countries with limited resources: the Indian experience with kidney paired donation.

    Science.gov (United States)

    Kute, Vivek B; Vanikar, Aruna V; Shah, Pankaj R; Gumber, Manoj R; Patel, Himanshu V; Engineer, Divyesh P; Modi, Pranjal R; Shah, Veena R; Trivedi, Hargovind L

    2014-10-01

    According to the Indian chronic kidney disease registry, in 2010 only 2% of end stage kidney disease patients were managed with kidney transplantation, 37% were managed with dialysis and 61% were treated conservatively without renal replacement therapy. In countries like India, where a well-organized deceased donor kidney transplantation program is not available, living donor kidney transplantation is the major source of organs for kidney transplantation. The most common reason to decline a donor for directed living donation is ABO incompatibility, which eliminates up to one third of the potential living donor pool. Because access to transplantation with human leukocyte antigen (HLA)-desensitization protocols and ABO incompatible transplantation is very limited due to high costs and increased risk of infections from more intense immunosuppression, kidney paired donation (KPD) promises hope to a growing number of end stage kidney disease patients. KPD is a rapidly growing and cost-effective living donor kidney transplantation strategy for patients who are incompatible with their healthy, willing living donor. In principle, KPD is feasible for any centre that performs living donor kidney transplantation. In transplant centres with a large living donor kidney transplantation program KPD does not require extra infrastructure, decreases waiting time, avoids transplant tourism and prevents commercial trafficking. Although KPD is still underutilized in India, it has been performed more frequently in recent times. To substantially increase donor pool and transplant rates, transplant centres should work together towards a national KPD program and frame a uniform acceptable allocation policy.

  16. Potential Impact of a Free Online HIV Treatment Response Prediction System for Reducing Virological Failures and Drug Costs after Antiretroviral Therapy Failure in a Resource-Limited Setting

    Directory of Open Access Journals (Sweden)

    Andrew D. Revell

    2013-01-01

    Full Text Available Objective. Antiretroviral drug selection in resource-limited settings is often dictated by strict protocols as part of a public health strategy. The objective of this retrospective study was to examine if the HIV-TRePS online treatment prediction tool could help reduce treatment failure and drug costs in such settings. Methods. The HIV-TRePS computational models were used to predict the probability of response to therapy for 206 cases of treatment change following failure in India. The models were used to identify alternative locally available 3-drug regimens, which were predicted to be effective. The costs of these regimens were compared to those actually used in the clinic. Results. The models predicted the responses to treatment of the cases with an accuracy of 0.64. The models identified alternative drug regimens that were predicted to result in improved virological response and lower costs than those used in the clinic in 85% of the cases. The average annual cost saving was $364 USD per year (41%. Conclusions. Computational models that do not require a genotype can predict and potentially avoid treatment failure and may reduce therapy costs. The use of such a system to guide therapeutic decision-making could confer health economic benefits in resource-limited settings.

  17. Translating vaccine policy into action: a report from the Bill & Melinda Gates Foundation Consultation on the prevention of maternal and early infant influenza in resource-limited settings.

    Science.gov (United States)

    Ortiz, Justin R; Neuzil, Kathleen M; Ahonkhai, Vincent I; Gellin, Bruce G; Salisbury, David M; Read, Jennifer S; Adegbola, Richard A; Abramson, Jon S

    2012-11-26

    Immunization of pregnant women against influenza is a promising strategy to protect the mother, fetus, and young infant from influenza-related diseases. The burden of influenza during pregnancy, the vaccine immunogenicity during this period, and the robust influenza vaccine safety database underpin recommendations that all pregnant women receive the vaccine to decrease complications of influenza disease during their pregnancies. Recent data also support maternal immunization for the additional purpose of preventing disease in the infant during the first six months of life. In April 2012, the WHO Strategic Advisory Group of Experts (SAGE) on Immunization recommended revisions to the WHO position paper on influenza vaccines. For the first time, SAGE recommended pregnant women should be made the highest priority for inactivated seasonal influenza vaccination. However, the variable maternal influenza vaccination coverage in countries with pre-existing maternal influenza vaccine recommendations underscores the need to understand and to address the discrepancy between recommendations and implementation success. We present the outcome of a multi-stakeholder expert consultation on inactivated influenza vaccination in pregnancy. The creation and implementation of vaccine policies and regulations require substantial resources and capacity. As with all public health interventions, the existence of perceived and real risks of vaccination will necessitate effective and transparent risk communication. Potential risk allocation and sharing mechanisms should be addressed by governments, vaccine manufacturers, and other stakeholders. In resource-limited settings, vaccine-related issues concerning supply, formulation, regulation, evidence evaluation, distribution, cost-utility, and post-marketing safety surveillance need to be addressed. Lessons can be learned from the Maternal and Neonatal Tetanus Elimination Initiative as well as efforts to increase vaccine coverage among pregnant

  18. Seasonal zooplankton dynamics in Lake Michigan: disentangling impacts of resource limitation, ecosystem engineering, and predation during a critical ecosystem transition

    Science.gov (United States)

    Vanderploeg, Henry A.; Pothoven, Steven A.; Fahnenstiel, Gary L.; Cavaletto, Joann F.; Liebig, James R.; Stow, Craig Stow; Nalepa, Thomas F.; Madenjian, Charles P.; Bunnell, David B.

    2012-01-01

    We examined seasonal dynamics of zooplankton at an offshore station in Lake Michigan from 1994 to 2003 and 2007 to 2008. This period saw variable weather, declines in planktivorous fish abundance, the introduction and expansion of dreissenid mussels, and a slow decline in total phosphorus concentrations. After the major expansion of mussels into deep water (2007–2008), chlorophyll in spring declined sharply, Secchi depth increased markedly in all seasons, and planktivorous fish biomass declined to record-low levels. Overlaying these dramatic ecosystem-level changes, the zooplankton community exhibited complex seasonal dynamics between 1994–2003 and 2007–2008. Phenology of the zooplankton maximum was affected by onset of thermal stratification, but there was no other discernable effect due to temperature. Interannual variability in zooplankton biomass during 1994 and 2003 was strongly driven by planktivorous fish abundance, particularly age-0 and age-1 alewives. In 2007–2008, there were large decreases in Diacyclops thomasi and Daphnia mendotae possibly caused by food limitation as well as increased predation and indirect negative effects from increases in Bythotrephes longimanus abundance and in foraging efficiency associated with increased light penetration. The Bythotrephes increase was likely driven in part by decreased predation from yearling and older alewife. While there was a major decrease in epilimnetic–metalimnetic herbivorous cladocerans in 2007–2008, there was an increase in large omnivorous and predacious calanoid copepods, especially those in the hypolimnion. Thus, changes to the zooplankton community are the result of cascading, synergistic interactions, including a shift from vertebrate to invertebrate planktivory and mussel ecosystem impacts on light climate and chlorophyll.

  19. Reducing Salinity by Flooding an Extremely Alkaline and Saline Soil Changes the Bacterial Community but Its Effect on the Archaeal Community Is Limited

    Science.gov (United States)

    de León-Lorenzana, Arit S.; Delgado-Balbuena, Laura; Domínguez-Mendoza, Cristina; Navarro-Noya, Yendi E.; Luna-Guido, Marco; Dendooven, Luc

    2017-01-01

    Regular flooding of the soil to reduce salinity will change soil characteristics, but also the microbial community structure. Soil of the former lake Texcoco with electrolytic conductivity (EC) 157.4 dS m-1 and pH 10.3 was flooded monthly in the laboratory under controlled conditions for 10 months while soil characteristics were determined and the archaeal and bacterial community structure monitored by means of 454 pyrosequencing of the 16S rRNA gene. The EC of the soil dropped from 157.8 to 1.7 dS m-1 and the clay content decreased from 430 to 270 g kg-1 after ten floodings, but the pH (10.3) did not change significantly over time. Flooding the soil had a limited effect on the archaeal community structure and only the relative abundance of Haloferax-like 16S rRNA phylotypes changed significantly. Differences in archaeal population structure were more defined by the initial physicochemical properties of the soil sample than by a reduction in salinity. Flooding, however, had a stronger effect on bacterial community structure than on the archaeal community structure. A wide range of bacterial taxa was affected significantly by changes in the soil characteristics, i.e., four phyla, nine classes, 17 orders, and 28 families. The most marked change occurred after only one flooding characterized by a sharp decrease in the relative abundance of bacterial groups belonging to the Gammaproteobacteria, e.g., Halomonadaceae (Oceanospirillales), Pseudomonadaceae, and Xanthomonadaceae and an increase in that of the [Rhodothermales] (Bacteroidetes), Nitriliruptorales (Actinobacteria), and unassigned Bacteria. It was found that flooding the soil sharply reduced the EC, but also the soil clay content. Flooding the soil had a limited effect on the archaeal community structure, but altered the bacterial community structure significantly. PMID:28396654

  20. Mentorship needs at academic institutions in resource-limited settings: a survey at makerere university college of health sciences

    Directory of Open Access Journals (Sweden)

    Nakwagala Fred

    2011-07-01

    Full Text Available Abstract Background Mentoring is a core component of medical education and career success. There is increasing global emphasis on mentorship of young scientists in order to train and develop the next leaders in global health. However, mentoring efforts are challenged by the high clinical, research and administrative demands. We evaluated the status and nature of mentoring practices at Makerere University College of Health Sciences (MAKCHS. Methods Pre-tested, self-administered questionnaires were sent by email to all Fogarty alumni at the MAKCHS (mentors and each of them was requested to complete and email back the questionnaire. In addition to training level and number of mentors, the questionnaires had open-ended questions covering themes such as; status of mentorship, challenges faced by mentors and strategies to improve and sustain mentorship within MAKCHS. Similarly, open-ended questionnaires were sent and received by email from all graduate students (mentees registered with the Uganda Society for Health Scientists (USHS. Qualitative data from mentors and mentees was analyzed manually according to the pre-determined themes. Results Twenty- two out of 100 mentors responded (14 email and 8 hard copy responses. Up to 77% (17/22 of mentors had Master's-level training and only 18% (4/22 had doctorate-level training. About 40% of the mentors had ≥ two mentees while 27% had none. Qualitative results showed that mentors needed support in terms of training in mentoring skills and logistical/financial support to carry out successful mentorship. Junior scientists and students reported that mentorship is not yet institutionalized and it is currently occurring in an adhoc manner. There was lack of awareness of roles of mentors and mentees. The mentors mentioned the limited number of practicing mentors at the college and thus the need for training courses and guidelines for faculty members in regard to mentorship at academic institutions. Conclusions

  1. On the influence of cell size in physically-based distributed hydrological modelling to assess extreme values in water resource planning

    Directory of Open Access Journals (Sweden)

    M. Egüen

    2012-05-01

    Full Text Available This paper studies the influence of changing spatial resolution on the implementation of distributed hydrological modelling for water resource planning in Mediterranean areas. Different cell sizes were used to investigate variations in the basin hydrologic response given by the model WiMMed, developed in Andalusia (Spain, in a selected watershed. The model was calibrated on a monthly basis from the available daily flow data at the reservoir that closes the watershed, for three different cell sizes, 30, 100, and 500 m, and the effects of this change on the hydrological response of the basin were analysed by means of the comparison of the hydrological variables at different time scales for a 3-yr-period, and the effective values for the calibration parameters obtained for each spatial resolution. The variation in the distribution of the input parameters due to using different spatial resolutions resulted in a change in the obtained hydrological networks and significant differences in other hydrological variables, both in mean basin-scale and values distributed in the cell level. Differences in the magnitude of annual and global runoff, together with other hydrological components of the water balance, became apparent. This study demonstrated the importance of choosing the appropriate spatial scale in the implementation of a distributed hydrological model to reach a balance between the quality of results and the computational cost; thus, 30 and 100-m could be chosen for water resource management, without significant decrease in the accuracy of the simulation, but the 500-m cell size resulted in significant overestimation of runoff and consequently, could involve uncertain decisions based on the expected availability of rainfall excess for storage in the reservoirs. Particular values of the effective calibration parameters are also provided for this hydrological model and the study area.

  2. Sustainability and long-term effectiveness of the WHO surgical safety checklist combined with pulse oximetry in a resource-limited setting: two-year update from Moldova.

    Science.gov (United States)

    Kim, Rebecca Y; Kwakye, Gifty; Kwok, Alvin C; Baltaga, Ruslan; Ciobanu, Gheorghe; Merry, Alan F; Funk, Luke M; Lipsitz, Stuart R; Gawande, Atul A; Berry, William R; Haynes, Alex B

    2015-05-01

    Little is known about the sustainability and long-term effect of surgical safety checklists when implemented in resource-limited settings. A previous study demonstrated the marked, short-term effect of a structured hospital-wide implementation of a surgical safety checklist in Moldova, a lower-middle-income country, as have studies in other low-resource settings. To assess the long-term reduction in perioperative harm following the introduction of a checklist-based surgical quality improvement program in a resource-limited setting and to understand the long-term effects of such programs. Twenty months after the initial implementation of a surgical safety checklist and the provision of pulse oximetry at a referral hospital in Moldova, a lower-middle-income, resource-limited country in Eastern Europe, we conducted a prospective study of perioperative care and outcomes of 637 consecutive patients undergoing noncardiac surgery (the long-term follow-up group), and we compared the findings with those from 2106 patients who underwent surgery shortly after implementation (the short-term follow-up group). Preintervention data were collected from March to July 2010. Data collection during the short-term follow-up period was performed from October 2010 to January 2011, beginning 1 month after the implementation of the launch period. Data collection during the long-term follow-up period took place from May 25 to July 6, 2012, beginning 20 months after the initial intervention. The primary end points of interest were surgical morbidity (ie, the complication rate), adherence to safety process measures, and frequency of hypoxemia. Between the short- and long-term follow-up groups, the complication rate decreased 30.7% (P = .03). Surgical site infections decreased 40.4% (P = .05). The mean (SD) rate of completion of the checklist items increased from 88% (14%) in the short-term follow-up group to 92% (11%) in the long-term follow-up group (P rate of hypoxemic events

  3. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W

    2016-01-01

    and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  4. Mathematical Modeling of Extreme Sports Injury Relief Logistics Resources Matching%对极限运动中损伤救助物流资源配比的数学建模

    Institute of Scientific and Technical Information of China (English)

    李凤; 陈婷婷

    2015-01-01

    极限运动发生的区域不同,一旦出现伤病,各地区采用的物流救援形式也不同.当前单一的救援方式很难满足多地区复杂性的要求.提出一种基于需求和供给均衡机制的极限运动损伤救助物流规划数学模型,采用二次加权平均方法构建极限运动损伤救助时效物流运输网络规划模型,模型不断调整已分配到路段上的损伤人员量,采用AGV控制救助物流堵塞评估问题,分析极限运动损伤救助人员物流设备需求的确定和供需平衡机制,面向人数、成本以及损伤程度三个因素明确极限运动人员损伤强度的评估指标体系,确定物资配送的时限要求和紧迫程度.实验结果说明,该种模型下的极限运动损伤救助效率、成本以及效用度都优于传统模型,具有较高的应用价值.%Extreme sports come from different areas, once appear, injuries, the logistics aid forms are also different among regions. The current single rescue way it is difficult to meet the requirements of the region more complexity. Put forward a kind of based on supply and demand equilibrium mechanism of extreme sports injury relief logistics planning model, qua-dratic weighted average method was used to construct limit movement damage relief aging logistics transportation network planning model, model of constantly adjust the amount of personnel assigned to the stretch of road damage, the AGV control relief logistics jams evaluation problems, analysis of extreme sports injury aid workers logistics equipment demand and sup-ply and demand balance mechanism, for the number of the degree of damage, costs, and three factors clearly extreme sports personnel damage strength evaluation index system, determine the time limits and pressing for distribution. Experimental results show that, under this kind of model of extreme sports injury salvage efficiency, cost and utility degree is superior to the traditional model, has higher application value.

  5. Making choices impairs subsequent self-control: a limited-resource account of decision making, self-regulation, and active initiative.

    Science.gov (United States)

    Vohs, Kathleen D; Baumeister, Roy F; Schmeichel, Brandon J; Twenge, Jean M; Nelson, Noelle M; Tice, Dianne M

    2008-05-01

    The current research tested the hypothesis that making many choices impairs subsequent self-control. Drawing from a limited-resource model of self-regulation and executive function, the authors hypothesized that decision making depletes the same resource used for self-control and active responding. In 4 laboratory studies, some participants made choices among consumer goods or college course options, whereas others thought about the same options without making choices. Making choices led to reduced self-control (i.e., less physical stamina, reduced persistence in the face of failure, more procrastination, and less quality and quantity of arithmetic calculations). A field study then found that reduced self-control was predicted by shoppers' self-reported degree of previous active decision making. Further studies suggested that choosing is more depleting than merely deliberating and forming preferences about options and more depleting than implementing choices made by someone else and that anticipating the choice task as enjoyable can reduce the depleting effect for the first choices but not for many choices.

  6. Dynamical Downscaling of Climate Change Impacts on Wind Energy Resources in the Contiguous United States by Using a Limited-Area Model with Scale-Selective Data Assimilation

    Directory of Open Access Journals (Sweden)

    Bin Liu

    2014-01-01

    Full Text Available By using a limited-area model (LAM in combination with the scale-selective data assimilation (SSDA approach, wind energy resources in the contiguous United States (CONUS were downscaled from IPCC CCSM3 global model projections for both current and future climate conditions. An assessment of climate change impacts on wind energy resources in the CONUS region was then conducted. Based on the downscaling results, when projecting into future climate under IPCC’s A1B scenario, the average annual wind speed experiences an overall shift across the CONUS region. From the current climate to the 2040s, the average annual wind speed is expected to increase from 0.1 to 0.2 m s−1 over the Great Plains, Northern Great Lakes Region, and Southwestern United States located southwest of the Rocky Mountains. When projecting into the 2090s from current climate, there is an overall increase in the Great Plains Region and Southwestern United States located southwest of the Rockies with a mean wind speed increase between 0 and 0.1 m s−1, while, the Northern Great Lakes Region experiences an even greater increase from current climate to 2090s than over the first few decades with an increase of mean wind speed from 0.1 to 0.4 m s−1.

  7. Improved Neuropsychological and Neurological Functioning Across Three Antiretroviral Regimens in Diverse Resource-Limited Settings: AIDS Clinical Trials Group Study A5199, the International Neurological Study

    Science.gov (United States)

    Robertson, K.; Jiang, H.; Kumwenda, J.; Supparatpinyo, K.; Evans, S.; Campbell, T. B.; Price, R.; Tripathy, S.; Kumarasamy, N.; La Rosa, A.; Santos, B.; Silva, M. T.; Montano, S.; Kanyama, C.; Faesen, S.; Murphy, R.; Hall, C.; Marra, C. M.; Marcus, C.; Berzins, B.; Allen, R.; Housseinipour, M.; Amod, F.; Sanne, I.; Hakim, J.; Walawander, A.; Nair, A.

    2012-01-01

    Background. AIDS Clinical Trials Group (ACTG) A5199 compared the neurological and neuropsychological (NP) effects of 3 antiretroviral regimens in participants infected with human immunodeficiency virus type 1 (HIV-1) in resource-limited settings. Methods. Participants from Brazil, India, Malawi, Peru, South Africa, Thailand, and Zimbabwe were randomized to 3 antiretroviral treatment arms: A (lamivudine-zidovudine plus efavirenz, n = 289), B (atazanavir, emtricitabine, and didanosine-EC, n = 293), and C (emtricitabine-tenofovir-disoproxil fumarate plus efavirenz, n = 278) as part of the ACTG PEARLS study (A5175). Standardized neurological and neuropsychological (NP) screening examinations (grooved pegboard, timed gait, semantic verbal fluency, and finger tapping) were administered every 24 weeks from February 2006 to May 2010. Associations with neurological and neuropsychological function were estimated from linear and logistic regression models using generalized estimating equations. Results. The median weeks on study was 168 (Q1 = 96, Q3 = 192) for the 860 participants. NP test scores improved (P  .10). Significant country effects were noted on all NP tests and neurological outcomes (P < .01). Conclusions. The study detected no significant differences in neuropsychological and neurological outcomes between randomized ART regimens. Significant improvement occurred in neurocognitive and neurological functioning over time after initiation of ARTs. The etiology of these improvements is likely multifactorial, reflecting reduced central nervous system HIV infection, better general health, and practice effects. This study suggests that treatment with either of the World Health Organization –recommended first-line antiretroviral regimens in resource-limited settings will improve neuropsychological functioning and reduce neurological dysfunction. Clinical trials registration.  NCT00096824. PMID:22661489

  8. Are Treponema pallidum specific rapid and point-of-care tests for syphilis accurate enough for screening in resource limited settings? Evidence from a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Yalda Jafari

    Full Text Available BACKGROUND: Rapid and point-of-care (POC tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP specific reference standards. METHODS: Five electronic databases (1980-2012 were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit. RESULTS: In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI for the sensitivities of popular tests were: i Determine, 90.04% (80.45, 95.21, ii SD Bioline, 87.06% (75.67, 94.50, iii VisiTect, 85.13% (72.83, 92.57, and iv Syphicheck, 74.48% (56.85, 88.44, while specificities were: i Syphicheck, 99.14% (96.37, 100, ii Visitect, 96.45% (91.92, 99.29, iii SD Bioline, 95.85% (89.89, 99.53, and iv Determine, 94.15% (89.26, 97.66. In whole blood samples, sensitivities were: i Determine, 86.32% (77.26, 91.70, ii SD Bioline, 84.50% (78.81, 92.61, iii Syphicheck, 74.47% (63.94, 82.13, and iv VisiTect, 74.26% (53.62, 83.68, while specificities were: i Syphicheck, 99.58% (98.91, 99.96, ii VisiTect, 99.43% (98.22, 99.98, iii SD Bioline, 97.95%(92.54, 99.33, and iv Determine, 95.85% (92.42, 97.74. CONCLUSIONS: Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource limited settings

  9. Are Treponema pallidum Specific Rapid and Point-of-Care Tests for Syphilis Accurate Enough for Screening in Resource Limited Settings? Evidence from a Meta-Analysis

    Science.gov (United States)

    Jafari, Yalda; Peeling, Rosanna W.; Shivkumar, Sushmita; Claessens, Christiane; Joseph, Lawrence; Pai, Nitika Pant

    2013-01-01

    Background Rapid and point-of-care (POC) tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP) specific reference standards. Methods Five electronic databases (1980–2012) were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit. Results In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI) for the sensitivities of popular tests were: i) Determine, 90.04% (80.45, 95.21), ii) SD Bioline, 87.06% (75.67, 94.50), iii) VisiTect, 85.13% (72.83, 92.57), and iv) Syphicheck, 74.48% (56.85, 88.44), while specificities were: i) Syphicheck, 99.14% (96.37, 100), ii) Visitect, 96.45% (91.92, 99.29), iii) SD Bioline, 95.85% (89.89, 99.53), and iv) Determine, 94.15% (89.26, 97.66). In whole blood samples, sensitivities were: i) Determine, 86.32% (77.26, 91.70), ii) SD Bioline, 84.50% (78.81, 92.61), iii) Syphicheck, 74.47% (63.94, 82.13), and iv) VisiTect, 74.26% (53.62, 83.68), while specificities were: i) Syphicheck, 99.58% (98.91, 99.96), ii) VisiTect, 99.43% (98.22, 99.98), iii) SD Bioline, 97.95%(92.54, 99.33), and iv) Determine, 95.85% (92.42, 97.74). Conclusions Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource

  10. Examining Geospatial Technology Tools to Compensate for Limited Exposures and Integrate Diverse Map and Data Resources in Geological Studies of the Southern Blue Ridge

    Science.gov (United States)

    Collins, N.; Ryan, J. G.

    2010-12-01

    Constraining the tectonic and metamorphic history of rock units in the southern Blue Ridge of western North Carolina is complicated by limited exposures and extensive vegetative cover, as well as burial by human development. Integrating varied data sources for field relations using cyberinformation tools may provide a means around such difficulties. We are examining several different Geographical Information Systems (GIS) tools as a means for effectively integrating available map data, both toward meeting research objectives as well as to facilitate classroom and field instruction. Commercial GIS platforms like ArcGIS and associated software can effectively integrate diverse geoscience information resources within a single platform. The Internet provides free access to databases ranging from geochemical datasets to topographical and structural data. Public domain geochemical databases like EarthChem provide spatially controlled elemental data on rock samples collected by many researchers over extended periods. Once incorporated within the ArcGIS template, this information can then be exported into free geospatial visualization applications such as Goggle Earth, as well as 3D manipulation programs like Fledermaus. Geospatially controlled USGS and NCGS geologic maps and geophysical datasets provide a useful base for examining mafic and ultramafic rock exposures in the Blue Ridge. One can resolve the exposures of specific rock types from these map resources within ArcGIS, as well as fault locations, and magnetics and gravity data. High-resolution DEMs permit data-intensive focusing on areas of interest, and Fledermaus manipulations permit 3D visualization. The output maps and visualizations are of publishable quality, and permit the manipulation of data across a region to infer contact trends and/or chemical or mineralogical, as well as to identify discontinuities that may be geologically relevant. “All-in-one” GIS applications like GeoMapApp have many of these

  11. Potential for Zika virus introduction and transmission in resource-limited countries in Africa and the Asia-Pacific region: a modelling study.

    Science.gov (United States)

    Bogoch, Isaac I; Brady, Oliver J; Kraemer, Moritz U G; German, Matthew; Creatore, Maria I; Brent, Shannon; Watts, Alexander G; Hay, Simon I; Kulkarni, Manisha A; Brownstein, John S; Khan, Kamran

    2016-11-01

    As the epidemic of Zika virus expands in the Americas, countries across Africa and the Asia-Pacific region are becoming increasingly susceptible to the importation and possible local spread of the virus. To support public health readiness, we aim to identify regions and times where the potential health, economic, and social effects from Zika virus are greatest, focusing on resource-limited countries in Africa and the Asia-Pacific region. Our model combined transportation network analysis, ecological modelling of mosquito occurrences, and vector competence for flavivirus transmission, using data from the International Air Transport Association, entomological observations from Zika's primary vector species, and climate conditions using WorldClim. We overlaid monthly flows of airline travellers arriving to Africa and the Asia-Pacific region from areas of the Americas suitable for year-round transmission of Zika virus with monthly maps of climatic suitability for mosquito-borne transmission of Zika virus within Africa and the Asia-Pacific region. An estimated 2·6 billion people live in areas of Africa and the Asia-Pacific region where the presence of competent mosquito vectors and suitable climatic conditions could support local transmission of Zika virus. Countries with large volumes of travellers arriving from Zika virus-affected areas of the Americas and large populations at risk of mosquito-borne Zika virus infection include India (67 422 travellers arriving per year; 1·2 billion residents in potential Zika transmission areas), China (238 415 travellers; 242 million residents), Indonesia (13 865 travellers; 197 million residents), Philippines (35 635 travellers; 70 million residents), and Thailand (29 241 travellers; 59 million residents). Many countries across Africa and the Asia-Pacific region are vulnerable to Zika virus. Strategic use of available health and human resources is essential to prevent or mitigate the health, economic, and social

  12. The clinical and economic impact of point-of-care CD4 testing in mozambique and other resource-limited settings: a cost-effectiveness analysis.

    Directory of Open Access Journals (Sweden)

    Emily P Hyle

    2014-09-01

    Full Text Available BACKGROUND: Point-of-care CD4 tests at HIV diagnosis could improve linkage to care in resource-limited settings. Our objective is to evaluate the clinical and economic impact of point-of-care CD4 tests compared to laboratory-based tests in Mozambique. METHODS AND FINDINGS: We use a validated model of HIV testing, linkage, and treatment (CEPAC-International to examine two strategies of immunological staging in Mozambique: (1 laboratory-based CD4 testing (LAB-CD4 and (2 point-of-care CD4 testing (POC-CD4. Model outcomes include 5-y survival, life expectancy, lifetime costs, and incremental cost-effectiveness ratios (ICERs. Input parameters include linkage to care (LAB-CD4, 34%; POC-CD4, 61%, probability of correctly detecting antiretroviral therapy (ART eligibility (sensitivity: LAB-CD4, 100%; POC-CD4, 90% or ART ineligibility (specificity: LAB-CD4, 100%; POC-CD4, 85%, and test cost (LAB-CD4, US$10; POC-CD4, US$24. In sensitivity analyses, we vary POC-CD4-specific parameters, as well as cohort and setting parameters to reflect a range of scenarios in sub-Saharan Africa. We consider ICERs less than three times the per capita gross domestic product in Mozambique (US$570 to be cost-effective, and ICERs less than one times the per capita gross domestic product in Mozambique to be very cost-effective. Projected 5-y survival in HIV-infected persons with LAB-CD4 is 60.9% (95% CI, 60.9%-61.0%, increasing to 65.0% (95% CI, 64.9%-65.1% with POC-CD4. Discounted life expectancy and per person lifetime costs with LAB-CD4 are 9.6 y (95% CI, 9.6-9.6 y and US$2,440 (95% CI, US$2,440-US$2,450 and increase with POC-CD4 to 10.3 y (95% CI, 10.3-10.3 y and US$2,800 (95% CI, US$2,790-US$2,800; the ICER of POC-CD4 compared to LAB-CD4 is US$500/year of life saved (YLS (95% CI, US$480-US$520/YLS. POC-CD4 improves clinical outcomes and remains near the very cost-effective threshold in sensitivity analyses, even if point-of-care CD4 tests have lower sensitivity

  13. Schwinger limit attainability with extreme power lasers.

    Science.gov (United States)

    Bulanov, Stepan S; Esirkepov, Timur Zh; Thomas, Alexander G R; Koga, James K; Bulanov, Sergei V

    2010-11-26

    High intensity colliding laser pulses can create abundant electron-positron pair plasma [A. R. Bell and J. G. Kirk, Phys. Rev. Lett. 101, 200403 (2008)], which can scatter the incoming electromagnetic waves. This process can prevent one from reaching the critical field of quantum electrodynamics at which vacuum breakdown and polarization occur. Considering the pairs are seeded by the Schwinger mechanism, it is shown that the effects of radiation friction and the electron-positron avalanche development in vacuum depend on the electromagnetic wave polarization. For circularly polarized colliding pulses, these effects dominate not only the particle motion but also the evolution of the pulses. For linearly polarized pulses, these effects are not as strong. There is an apparent analogy of these cases with circular and linear electron accelerators to the corresponding constraining and reduced roles of synchrotron radiation losses.

  14. From invasion to latency: intracellular noise and cell motility as key controls of the competition between resource-limited cellular populations

    KAUST Repository

    Guerrero, Pilar

    2015-04-02

    © 2015, Springer-Verlag Berlin Heidelberg. In this paper we analyse stochastic models of the competition between two resource-limited cell populations which differ in their response to nutrient availability: the resident population exhibits a switch-like response behaviour while the invading population exhibits a bistable response. We investigate how noise in the intracellular regulatory pathways and cell motility influence the fate of the incumbent and invading populations. We focus initially on a spatially homogeneous system and study in detail the role of intracellular noise. We show that in such well-mixed systems, two distinct regimes exist: In the low (intracellular) noise limit, the invader has the ability to invade the resident population, whereas in the high noise regime competition between the two populations is found to be neutral and, in accordance with neutral evolution theory, invasion is a random event. Careful examination of the system dynamics leads us to conclude that (i) even if the invader is unable to invade, the distribution of survival times, PS(t), has a fat-tail behaviour (PS(t)∼t-1) which implies that small colonies of mutants can coexist with the resident population for arbitrarily long times, and (ii) the bistable structure of the invading population increases the stability of the latent population, thus increasing their long-term likelihood of survival, by decreasing the intensity of the noise at the population level. We also examine the effects of spatial inhomogeneity. In the low noise limit we find that cell motility is positively correlated with the aggressiveness of the invader as defined by the time the invader takes to invade the resident population: the faster the invasion, the more aggressive the invader.

  15. Statistics of Extremes

    KAUST Repository

    Davison, Anthony C.

    2015-04-10

    Statistics of extremes concerns inference for rare events. Often the events have never yet been observed, and their probabilities must therefore be estimated by extrapolation of tail models fitted to available data. Because data concerning the event of interest may be very limited, efficient methods of inference play an important role. This article reviews this domain, emphasizing current research topics. We first sketch the classical theory of extremes for maxima and threshold exceedances of stationary series. We then review multivariate theory, distinguishing asymptotic independence and dependence models, followed by a description of models for spatial and spatiotemporal extreme events. Finally, we discuss inference and describe two applications. Animations illustrate some of the main ideas. © 2015 by Annual Reviews. All rights reserved.

  16. Utility of a limited panel of calretinin and Ber-EP4 immunocytochemistry on cytospin preparation of serous effusions: A cost-effective measure in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Raman Arora

    2011-01-01

    Full Text Available Background: Differentiation between reactive, but morphologically atypical, mesothelial cells and adenocarcinoma in effusions can be problematic. Elaborate immunohistochemical panels have been devised. Techniques like DNA analysis, flow/image cytometry, and K-ras mutation analysis are research oriented and difficult to perform in routine, especially in resource-poor centers. We evaluated the efficacy of a limited two-antibody panel comprising calretinin and Ber-EP4 on cytospin and cell block preparations, in 100 effusion samples. Materials and Methods: Fifty cases of reactive mesothelial hyperplasia and 50 cases of adenocarcinoma diagnosed by cytomorphology in ascitic/pleural fluid specimens over a 2-year period were assessed. The diagnoses were confirmed by clinical/histopathologic correlation. Cytospin smears were made in all. Cell blocks were prepared, wherever adequate fluid was available. Immunocytochemistry (ICC for calretinin and Ber-EP4 was performed. Results: Forty-five of the reactive effusion cases (90% were calretinin reactive and Ber-EP4 negative. Among the adenocarcinoma cases, 49 (98% were calretinin negative but Ber-EP4 positive. Thus, both calretinin and Ber-EP4 had a high sensitivity (90% and 98%, respectively, as well as a high specificity (100% and 86%, respectively. In the 21 reactive mesothelial cases, whose cell blocks were made, results were comparable to those on cytospin. However, of the 19 adenocarcinoma cases in which cell blocks were prepared, all were Ber-EP4 immunopositive except for three, which were positive on cytospin, implying false-negative results on cell blocks. Conclusions: A limited panel of two monoclonal antibodies, calretinin and Ber-EP4, may be useful in cytology, as a "primary antibody panel", for accurate diagnosis and patient management. Additionally, ICC can be performed easily on cytospin preparations, which gave results comparable to cell blocks in our study.

  17. How can we improve outcomes for patients and families under palliative care? implementing clinical audit for quality improvement in resource limited settings

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    Lucy Selman

    2010-01-01

    Full Text Available Palliative care in India has made enormous advances in providing better care for patients and families living with progressive disease, and many clinical services are well placed to begin quality improvement initiatives, including clinical audit. Clinical audit is recognized globally to be essential in all healthcare, as a way of monitoring and improving quality of care. However, it is not common in developing country settings, including India. Clinical audit is a cyclical activity involving: identification of areas of care in need of improvement, through data collection and analysis utilizing an appropriate questionnaire; setting measurable quality of care targets in specific areas; designing and implementing service improvement strategies; and then re-evaluating quality of care to assess progress towards meeting the targets. Outcome measurement is an important component of clinical audit that has additional advantages; for example, establishing an evidence base for the effectiveness of services. In resource limited contexts, outcome measurement in clinical audit is particularly important as it enables service development to be evidence-based and ensures resources are allocated effectively. Key success factors in conducting clinical audit are identified (shared ownership, training, managerial support, inclusion of all members of staff and a positive approach. The choice of outcome measurement tool is discussed, including the need for a culturally appropriate and validated measure which is brief and simple enough to incorporate into clinical practice and reflects the holistic nature of palliative care. Support for clinical audit is needed at a national level, and development and validation of an outcome measurement tool in the Indian context is a crucial next step.

  18. Characterizing breast conditions at an open-access breast clinic in South Africa: a model that is more than cancer care for a resource-limited setting.

    Science.gov (United States)

    Rayne, Sarah; Lince-Deroche, Naomi; Hendrickson, Cheryl; Shearer, Kate; Moyo, Faith; Michelow, Pam; Rubin, Grace; Benn, Carol; Firnhaber, Cynthia

    2017-01-21

    While most breast-related research focuses on cancer, presentation of symptomatic persons in non-screened environments requires understanding the spectrum of breast diseases so as to plan services in resource-constrained settings. This study presents the variety of breast disease managed at a government, open-access breast clinic in South Africa. We performed a retrospective file review using a systematic random sample of patients 18 years and above presenting for breast care over a 14-month period. We collected demographics, clinical characteristics, management and final diagnoses from the first visit and twelve subsequent months. The final sample contained 365 individuals (97 · 5% women). Most were black, unmarried and South African citizens with a median age of 43 years (IQR 31-55) . Of those reporting their status (24 · 1%) 38 · 6% were HIV-positive. A mass (57 · 0%) and/or pain (28 · 5%) were the most common symptoms. Imaging and breast biopsies were required in 78 and 25% of individuals, respectively. Nearly half of biopsies identified breast cancer (44 · 1% of women ≤40 and 57 · 3% for women >40). Benign conditions (47 · 7%) and no abnormality (18 · 2%) were common final classifications among women. There was no difference between the final classifications of patients who self-referred versus those who were formally referred from another health care provider. Nearly half of the participants (46 · 6%) travelled 20 km or more to attend the clinic. Benign breast conditions far outweighed cancer diagnoses. As breast cancer awareness increases in resource-limited countries, facilities offering breast care require administrative and clinical preparation to manage a range of non-cancer related conditions.

  19. Using dried blood spots collected under field condition to determine HIV-1 diversity and drug resistance mutations in resource limited Tanzania

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    James Kimaro

    2014-11-01

    Full Text Available Introduction: A dried blood spot (DBS on filter paper has been used for different tests globally and has gained popularities in resource limited settings especially during HIV/AIDS epidemic. We assessed the efficiency of molecular characterization of HIV-1 subtypes using DBS collected under field conditions in northern Tanzania. Materials and Methods: In 2011 and 2012, 60 DBS samples were collected under field conditions from exposed and newly diagnosed HIV-1 infected children from Kilimanjaro (n=20, Arusha (n=20, Tanga (n=10 and Manyara (n=10. Results and discussion: Of 60 DBS analyzed at both Protease (PR and Reverse Transcriptase (RT regions, 45 (75% were analyzed, including 17 (85% from Kilimanjaro, 15 (75% from Arusha, 8 (80% from Tanga, and 5 (50% from Manyara region. All 45 DBS characterized had viral load above 1000 copies/mL with mean log10 viral loads of 3.87 copies/mL (SD 0.995. The phylogenetic results indicated presence of subtype and circulating recombinant form (CRF. In which, 24 were subtype A1 (53.33%, 16 were subtype C (35.55%, 3 were subtype D (6.67% and 2 were CRF10_CD (4.35%. All major mutations were detected in the RT region, none from protease (PR region. The mutations detected were Y181C (n=8, K103 (n=4 and G190A (n=1, conferring resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs, and M184V (n=1, conferring resistance to lamivudine and emtricitabine. Conclusions: Our results indicate that DBS collected from field conditions in resource scarcity areas can be used to determine the phylogeny of the virus and drug resistance mutations in areas with diverse HIV-1 group M subtypes.

  20. Pollen and resource limitations to lifetime seed production in a wild population of the endangered plant Disanthus cercidifollus var.Iongipes H.T.Chang (Hamamelidaceae)

    Institute of Scientific and Technical Information of China (English)

    XIAO Yian; HE Ping; ZENG Jianjun; LI Xiaohong; HU Wenhai

    2007-01-01

    Disanthus cercidifolius Maxim.var.longipes H.T.Chang,a plant species that only occurs in a few counties in Hunan,Jiangxi and Zhejiang Provinces and with a relatively small number of individuals,is ranked as a second Class endangered species for conservation in China.We have studied the effect of pollen and resources available to female reproduction,and the reproductive mechanism of "excess flowers with low fruit set" in Disanthus cercidifolius Maxim.var.longipes H.T.Chang was discussed.Results are as follows:Pollen from different sources has significant effects on fruit set and seed set of Disanthus cercidifolius Maxim.var.longipes H.T.Chang.The pollen source rather than pollen numbers significantly affected reproduction of this species.In wild populations,producing one fruit needs about 54.8 flowers,and one satiation seed needs about 6.60 flowers or 83.19 ovules.After fertilizing,which was propitious to flower development,the abortion rate of flower buds was decreasing,but the flowering rate was increasing.The fruit set and seed set was also significantly increasing,while abortion rate of fruit was significantly decreasing.With the increasing percentages of cutting leaves,the fruit set decreased,but the abortion rate of fruit shows no significant differentiation among treatments.After cutting branches that were puny,broken and insectinfested branches,the flower number seemed to be decreasing,but the fruit set and seed set all increased significantly.After removing some flowers,the fruit set was calculated with respect to the number of flowers remaining after the treatment increased with increasing of percentages of flower removal,whereas fruit set calculated with respect to the initial number of flowers remained constant,and the mean weights of per fi'uit and per seed all decreased significantly.Sufficient spatial or temporal heterogeneities in nutrient levels might allow limitation of seed set by resources and pollen in a natural population,while supplying

  1. Surgery for Conditions of Infectious Etiology in Resource-Limited Countries Affected by Crisis: The Médecins Sans Frontières Operations Centre Brussels Experience

    Science.gov (United States)

    Sharma, Davina; Hayman, Kate; Dominguez, Lynette; Trelles, Miguel; Saqeb, Sanaulhaq; Kasonga, Cheride; Hangi, Theophile Kubuya; Mupenda, Jerome; Naseer, Aamer; Wong, Evan; Kushner, Adam L.

    2015-01-01

    Abstract Background: Surgery for infection represents a substantial, although undefined, disease burden in low- and middle-income countries (LMICs). Médecins Sans Frontières–Operations Centre Brussels (MSF-OCB) provides surgical care in LMICs and collects data useful for describing operative epidemiology of surgical need otherwise unmet by national health services. This study aimed to describe the experience of MSF-OCB operations for infections in LMICs. By doing so, the results might aid effective resource allocation and preparation of future humanitarian staff. Methods: Procedures performed in operating rooms at facilities run by MSF-OCB from July 2008 through June 2014 were reviewed. Projects providing specialty care only were excluded. Procedures for infection were described and related to demographics and reason for humanitarian response. Results: A total of 96,239 operations were performed at 27 MSF-OCB sites in 15 countries between 2008 and 2014. Of the 61,177 general operations, 7,762 (13%) were for infections. Operations for skin and soft tissue infections were the most common (64%), followed by intra-abdominal (26%), orthopedic (6%), and tropical infections (3%). The proportion of operations for skin and soft tissue infections was highest during natural disaster missions (p<0.001), intra-abdominal infections during hospital support missions (p<0.001) and orthopedic infections during conflict missions (p<0.001). Conclusion: Surgical infections are common causes for operation in LMICs, particularly during crisis. This study found that infections require greater than expected surgical input given frequent need for serial operations to overcome contextual challenges and those associated with limited resources in other areas (e.g., ward care). Furthermore, these results demonstrate that the pattern of operations for infections is related to nature of the crisis. Incorporating training into humanitarian preparation (e.g., surgical sepsis care, ultrasound

  2. Likelihood estimators for multivariate extremes

    KAUST Repository

    Huser, Raphaël

    2015-11-17

    The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model.

  3. Assessment of the impact of adherence and other predictors during HAART on various CD4 cell responses in resource-limited settings

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    Abrogoua DP

    2012-03-01

    Full Text Available Danho Pascal Abrogoua1,2, Brou Jerome Kablan1, Boua Alexis Thierry Kamenan1,3, Gilles Aulagner4, Konan N'Guessan1, Christian Zohoré11Laboratoire de Pharmacie Clinique, Pharmacologie et Therapeutique – UFR Sciences Pharmaceutiques et Biologiques, 2Laboratoire de Pharmacologie Clinique, CHU de Cocody, 3Service de Pharmacie, CHU de Cocody, Abidjan, Cote d'Ivoire, 4Service Pharmaceutique Hopital Louis Pradel, Lyon, FranceObjective: The aim of this study was to quantify, by modeling, the impact of significant predictors on CD4 cell response during antiretroviral therapy in a resource-limited setting.Methods: Modeling was used to determine which antiretroviral therapy response predictors (baseline CD4 cell count, clinical state, age, and adherence significantly influence immunological response in terms of CD4 cell gain compared to a reference value at different periods of monitoring.Results: At 6 months, CD4 cell response was significantly influenced by baseline CD4 count alone. The probability of no increase in CD4 cells was 2.6 higher in patients with a baseline CD4 cell count of ≥200/mm3. At 12 months, CD4 cell response was significantly influenced by both baseline CD4 cell count and adherence. The probability of no increase in CD4 cells was three times higher in patients with a baseline CD4 cell count of ≥200/mm3 and 0.15 times lower with adherent patients. At 18 months, CD4 cell response was also significantly influenced by both baseline CD4 cell count and adherence. The probability of no increase in CD4 cells was 5.1 times higher in patients with a baseline CD4 cell count of ≥200/mm3 and 0.28 times lower with adherent patients. At 24 months, optimal CD4 cell response was significantly influenced by adherence alone. Adherence increased the probability (by 5.8 of an optimal increase in CD4 cells. Age and baseline clinical state had no significant influence on immunological response.Conclusion: The relationship between adherence and CD4

  4. Mortality of patients lost to follow-up in antiretroviral treatment programmes in resource-limited settings: systematic review and meta-analysis.

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    Martin W G Brinkhof

    Full Text Available BACKGROUND: The retention of patients in antiretroviral therapy (ART programmes is an important issue in resource-limited settings. Loss to follow up can be substantial, but it is unclear what the outcomes are in patients who are lost to programmes. METHODS AND FINDINGS: We searched the PubMed, EMBASE, Latin American and Caribbean Health Sciences Literature (LILACS, Indian Medlars Centre (IndMed and African Index Medicus (AIM databases and the abstracts of three conferences for studies that traced patients lost to follow up to ascertain their vital status. Main outcomes were the proportion of patients traced, the proportion found to be alive and the proportion that had died. Where available, we also examined the reasons why some patients could not be traced, why patients found to be alive did not return to the clinic, and the causes of death. We combined mortality data from several studies using random-effects meta-analysis. Seventeen studies were eligible. All were from sub-Saharan Africa, except one study from India, and none were conducted in children. A total of 6420 patients (range 44 to 1343 patients were included. Patients were traced using telephone calls, home visits and through social networks. Overall the vital status of 4021 patients could be ascertained (63%, range across studies: 45% to 86%; 1602 patients had died. The combined mortality was 40% (95% confidence interval 33%-48%, with substantial heterogeneity between studies (P<0.0001. Mortality in African programmes ranged from 12% to 87% of patients lost to follow-up. Mortality was inversely associated with the rate of loss to follow up in the programme: it declined from around 60% to 20% as the percentage of patients lost to the programme increased from 5% to 50%. Among patients not found, telephone numbers and addresses were frequently incorrect or missing. Common reasons for not returning to the clinic were transfer to another programme, financial problems and improving or

  5. Diagnostic accuracy of two multiplex real-time polymerase chain reaction assays for the diagnosis of meningitis in children in a resource-limited setting

    Science.gov (United States)

    Khumalo, Jermaine; Nicol, Mark; Hardie, Diana; Muloiwa, Rudzani; Mteshana, Phindile

    2017-01-01

    Introduction Accurate etiological diagnosis of meningitis is important, but difficult in resource-limited settings due to prior administration of antibiotics and lack of viral diagnostics. We aimed to develop and validate 2 real-time multiplex PCR (RT-PCR) assays for the detection of common causes of community-acquired bacterial and viral meningitis in South African children. Methods We developed 2 multiplex RT- PCRs for detection of S. pneumoniae, N. meningitidis, H. influenzae, enteroviruses, mumps virus and herpes simplex virus. We tested residual CSF samples from children presenting to a local paediatric hospital over a one-year period, whose CSF showed an abnormal cell count. Results were compared with routine diagnostic tests and the final discharge diagnosis. We calculated accuracy of the bacterial RT-PCR assay compared to CSF culture and using World Health Organisation definitions of laboratory-confirmed bacterial meningitis. Results From 292 samples, bacterial DNA was detected in 12 (4.1%) and viral nucleic acids in 94 (32%). Compared to CSF culture, the sensitivity and specificity of the bacterial RT-PCR was 100% and 97.2% with complete agreement in organism identification. None of the cases positive by viral RT-PCR had a bacterial cause confirmed on CSF culture. Only 9/90 (10%) of patients diagnosed clinically as bacterial meningitis or partially treated bacterial meningitis tested positive with the bacterial RT-PCR. Discussion In this population the use of 2 multiplex RT-PCRs targeting 6 common pathogens gave promising results. If introduced into routine diagnostic testing, these multiplex RT-PCR assays would supplement other diagnostic tests, and have the potential to limit unnecessary antibiotic therapy and hospitalisation. PMID:28346504

  6. Development of rapid phenotypic system for the identification of Gram-negative oxidase-positive bacilli in resource-limited settings

    Indian Academy of Sciences (India)

    Mahmooda Kazmi; Adnan Khan; Shahana Urooj Kazmi

    2013-06-01

    Rapid and accurate identification of bacterial pathogens is a fundamental goal of clinical microbiology. The diagnosis and surveillance of diseases is dependent, to a great extent, on laboratory services, which cannot function without effective reliable reagents and diagnostics. Despite the advancement in microbiology diagnosis globally, resource-limited countries still struggle to provide an acceptable diagnosis quality which helps in clinical disease management and improve their mortality and morbidity data. During this study an indigenous product, Quick Test Strip (QTS) NE, was developed for the rapid identification of biochemically slower group of Gram-negative oxidase-positive bacilli that covers 19 different bacterial genera. Some of the members belonging to these groups are well-established human pathogens, e.g. various species of Vibrio, Pseudomonas, Burkholderia, Aeromonas, Achromobacter and Stenotrophomonas. This study also evaluates the performance of QTS-NE by comparing with genotypic characterization methods. A total of 232 clinical and reference bacterial isolates were tested by three different methods. QTS-NE provides 100% concordant results with other rapid identification and molecular characterization methods and confirms the potential to be used in clinical diagnosis.

  7. Retention of HIV-Infected Children in the First 12 Months of Anti-Retroviral Therapy and Predictors of Attrition in Resource Limited Settings: A Systematic Review.

    Science.gov (United States)

    Abuogi, Lisa L; Smith, Christiana; McFarland, Elizabeth J

    2016-01-01

    Current UNAIDS goals aimed to end the AIDS epidemic set out to ensure that 90% of all people living with HIV know their status, 90% initiate and continue life-long anti-retroviral therapy (ART), and 90% achieve viral load suppression. In 2014 there were an estimated 2.6 million children under 15 years of age living with HIV, of which only one-third were receiving ART. Little literature exists describing retention of HIV-infected children in the first year on ART. We conducted a systematic search for English language publications reporting on retention of children with median age at ART initiation less than ten years in resource limited settings. The proportion of children retained in care on ART and predictors of attrition were identified. Twelve studies documented retention at one year ranging from 71-95% amongst 31877 African children. Among the 5558 children not retained, 4082 (73%) were reported as lost to follow up (LFU) and 1476 (27%) were confirmed to have died. No studies confirmed the outcomes of children LFU. Predictors of attrition included younger age, shorter duration of time on ART, and severe immunosuppression. In conclusion, significant attrition occurs in children in the first 12 months after ART initiation, the majority attributed to LFU, although true outcomes of children labeled as LFU are unknown. Focused efforts to ensure retention and minimize early mortality are needed as universal ART for children is scaled up.

  8. Perceptions regarding menstruation and Practices during menstrual cycles among high school going adolescent girls in resource limited settings around Bangalore city, Karnataka, India

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    Shanbhag D

    2012-07-01

    Full Text Available Introduction: Hygiene-related practices of adolescents during menstruation are of importance, as it has a health impact in terms of increased vulnerability to reproductive tract infections (RTI. Therefore, increased knowledge about menstruation right from childhood may escalate safe practices and may help in mitigating the suffering of women.Objectives: To assess the perceptions and practices regarding menstrual hygiene among selected high school girls in a resource limited settings in area around Bangalore city. Methodology: This was a cross sectional study done in four selected Government High Schools in rural areas around Bangalore City. A pre-designed, pre-tested and structured questionnaire was administered. Results: A total of 506 girls were interviewed. The average age was 14.08 with Standard deviation of 1.06 and range between 12-16yrs. 99.6% of the students had heard of menstruation and 57.9% had acquired this even knowledge before attaining menarche. 73.7% knew that menstruation was a normal phenomenon but only 28.7% had knowledge regarding menstruation. 48.1% did not know that menstruation was related to pregnancy. Only 44.1% used sanitary pad during the menstrual cycles. Among those who used cloth, only 31.3% used soap and water to clean them. 56.8% used soap and water to clean their genital organs and 88.8% of the girls took bath daily during menstruation

  9. The role of point-of-care tests in antibiotic stewardship for urinary tract infections in a resource-limited setting on the Thailand-Myanmar border.

    Science.gov (United States)

    Chalmers, Lauren; Cross, Jessica; Chu, Cindy S; Phyo, Aung Pyae; Trip, Margreet; Ling, Clare; Carrara, Verena; Watthanaworawit, Wanitda; Keereecharoen, Lily; Hanboonkunupakarn, Borimas; Nosten, François; McGready, Rose

    2015-10-01

    Published literature from resource-limited settings is infrequent, although urinary tract infections (UTI) are a common cause of outpatient presentation and antibiotic use. Point-of-care test (POCT) interpretation relates to antibiotic use and antibiotic resistance. We aimed to assess the diagnostic accuracy of POCT and their role in UTI antibiotic stewardship. One-year retrospective analysis in three clinics on the Thailand-Myanmar border of non-pregnant adults presenting with urinary symptoms. POCT (urine dipstick and microscopy) were compared to culture with significant growth classified as pure growth of a single organism >10(5)  CFU/ml. In 247 patients, 82.6% female, the most common symptoms were dysuria (81.2%), suprapubic pain (67.8%) and urinary frequency (53.7%). After excluding contaminated samples, UTI was diagnosed in 52.4% (97/185); 71.1% (69/97) had a significant growth on culture, and >80% of these were Escherichia coli (20.9% produced extended-spectrum β-lactamase (ESBL)). Positive urine dipstick (leucocyte esterase ≥1 and/or nitrate positive) compared against positive microscopy (white blood cell >10/HPF, bacteria ≥1/HPF, epithelial cells setting. Appropriate prescribing is improved with concurrent use and concordant results of urine dipstick and microscopy. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  10. Impact of two interventions on timeliness and data quality of an electronic disease surveillance system in a resource limited setting (Peru: a prospective evaluation

    Directory of Open Access Journals (Sweden)

    Quispe Jose A

    2009-03-01

    Full Text Available Abstract Background A timely detection of outbreaks through surveillance is needed in order to prevent future pandemics. However, current surveillance systems may not be prepared to accomplish this goal, especially in resource limited settings. As data quality and timeliness are attributes that improve outbreak detection capacity, we assessed the effect of two interventions on such attributes in Alerta, an electronic disease surveillance system in the Peruvian Navy. Methods 40 Alerta reporting units (18 clinics and 22 ships were included in a 12-week prospective evaluation project. After a short refresher course on the notification process, units were randomly assigned to either a phone, visit or control group. Phone group sites were called three hours before the biweekly reporting deadline if they had not sent their report. Visit group sites received supervision visits on weeks 4 & 8, but no phone calls. The control group sites were not contacted by phone or visited. Timeliness and data quality were assessed by calculating the percentage of reports sent on time and percentage of errors per total number of reports, respectively. Results Timeliness improved in the phone group from 64.6% to 84% in clinics (+19.4 [95% CI, +10.3 to +28.6]; p Conclusion Regular phone reminders significantly improved timeliness of reports in clinics and ships, whereas supervision visits led to improved data quality only among clinics. Further investigations are needed to establish the cost-effectiveness and optimal use of each of these strategies.

  11. Excessive early mortality in the first year of treatment in HIV type 1-infected patients initiating antiretroviral therapy in resource-limited settings.

    Science.gov (United States)

    Marazzi, Maria Cristina; Liotta, Giuseppe; Germano, Paola; Guidotti, Giovanni; Altan, A Doro; Ceffa, Susanna; Lio, Massimo Magnano San; Nielsen-Saines, Karin; Palombi, Leonardo

    2008-04-01

    The response to treatment and risk factors for early mortality following initiation of combination antiretrovirals(ARVs) in a cohort of African patients are described in a retrospective cohort design. Medical history, laboratory parameters, and mortality data were reviewed for patients initiating ARVs in 12 clinical centers in Mozambique, Tanzania, and Malawi. Among 3456 HIV-1-infected patients who received ARVs for more than 6 months, at baseline 72% had WHO clinical stages 3/4, 7% had a viral load 400 copies/ml, and 38% had a CD4 cell count >200/microl. One year later, 78% had undetectable virus loads and 79% had CD4 cell counts >200 cells/mm3. In the first year of HAART 260 deaths occurred (97 per 1000 person/years) with mortality peaking in the first 3 months. The highest mortality was observed in patients with low BMI, low hemoglobin levels, and CD4 values <200 cells/microl at baseline. Mortality rates following initiation of HAART are higher in patients in resource-limited areas, particularly in the first 90 days following treatment initiation.HAART initiated at higher CD4 cell count levels, especially among malnourished and/or anemic patients, will carry significant public health impact.

  12. Cognitive-Behavioral Stress Management Interventions for Ethnic-Minority HIV-Positive Alcohol/Drug Abusers in Resource Limited and Culturally Diverse Communities

    Directory of Open Access Journals (Sweden)

    Robert M. Malow

    2009-01-01

    Full Text Available The article reports our intervention work with Alcohol and Other Drug Abusing (AOD People Living With HIV (PLWH. Present research has involved adapting Cognitive Behavioral Stress Management (CBSM and other strategies to improve quality of life and health outcomes for PLWH. Historically, CBSM has used relaxation and coping skills training to reduce negative mood and improve coping behaviors. The efficacy of CBSM interventions to improve functioning has been demonstrated in many disease groups and, more recently, in ethnic-minority HIV+ samples in the US CBSM HIV risk reduction interventions are similar to other cognitive-behavioral therapies in emphasizing skills training and stress reduction. Among the most precarious and challenging clinical populations are HIV infected individuals with a history of alcohol and/or drug abuse. Compared to their counterparts with no history of alcohol or drug abuse, not only are they more likely to transmit the virus to others, but they are also at risk for problems in adhering to antiretroviral regimens. A main focus of this article is to report on our intervention work with very resource-limited, ethnic-minority PLWH with substance abuse problems, particularly our NIH funded projects in Miami and Haiti and the opportunities presented by the emerging science of biological vulnerability and genomic factors.

  13. Impact of community-based support services on antiretroviral treatment programme delivery and outcomes in resource-limited countries: a synthetic review

    Directory of Open Access Journals (Sweden)

    Wouters Edwin

    2012-07-01

    Full Text Available Abstract Background Task-shifting to lay community health providers is increasingly suggested as a potential strategy to overcome the barriers to sustainable antiretroviral treatment (ART scale-up in high-HIV-prevalence, resource-limited settings. The dearth of systematic scientific evidence on the contributory role and function of these forms of community mobilisation has rendered a formal evaluation of the published results of existing community support programmes a research priority. Methods We reviewed the relevant published work for the period from November 2003 to December 2011 in accordance with the guidelines for a synthetic review. ISI Web of Knowledge, Science Direct, BioMed Central, OVID Medline, PubMed, Social Services Abstracts, and Sociological Abstracts and a number of relevant websites were searched. Results The reviewed literature reported an unambiguous positive impact of community support on a wide range of aspects, including access, coverage, adherence, virological and immunological outcomes, patient retention and survival. Looking at the mechanisms through which community support can impact ART programmes, the review indicates that community support initiatives are a promising strategy to address five often cited challenges to ART scale-up, namely (1 the lack of integration of ART services into the general health system; (2 the growing need for comprehensive care, (3 patient empowerment, (4 and defaulter tracing; and (5 the crippling shortage in human resources for health. The literature indicates that by linking HIV/AIDS-care to other primary health care programmes, by providing psychosocial care in addition to the technical-medical care from nurses and doctors, by empowering patients towards self-management and by tracing defaulters, well-organised community support initiatives are a vital part of any sustainable public-sector ART programme. Conclusions The review demonstrates that community support initiatives are a

  14. Feasibility of establishing a biosafety level 3 tuberculosis culture laboratory of acceptable quality standards in a resource-limited setting: an experience from Uganda.

    Science.gov (United States)

    Ssengooba, Willy; Gelderbloem, Sebastian J; Mboowa, Gerald; Wajja, Anne; Namaganda, Carolyn; Musoke, Philippa; Mayanja-Kizza, Harriet; Joloba, Moses Lutaakome

    2015-01-15

    Despite the recent innovations in tuberculosis (TB) and multi-drug resistant TB (MDR-TB) diagnosis, culture remains vital for difficult-to-diagnose patients, baseline and end-point determination for novel vaccines and drug trials. Herein, we share our experience of establishing a BSL-3 culture facility in Uganda as well as 3-years performance indicators and post-TB vaccine trials (pioneer) and funding experience of sustaining such a facility. Between September 2008 and April 2009, the laboratory was set-up with financial support from external partners. After an initial procedure validation phase in parallel with the National TB Reference Laboratory (NTRL) and legal approvals, the laboratory registered for external quality assessment (EQA) from the NTRL, WHO, National Health Laboratories Services (NHLS), and the College of American Pathologists (CAP). The laboratory also instituted a functional quality management system (QMS). Pioneer funding ended in 2012 and the laboratory remained in self-sustainability mode. The laboratory achieved internationally acceptable standards in both structural and biosafety requirements. Of the 14 patient samples analyzed in the procedural validation phase, agreement for all tests with NTRL was 90% (P culture, identification, and drug susceptibility testing (DST). The annual culture workload was 7,636, 10,242, and 2,712 inoculations for the years 2010, 2011, and 2012, respectively. Other performance indicators of TB culture laboratories were also monitored. Scores from EQA panels included smear microscopy >80% in all years from NTRL, CAP, and NHLS, and culture was 100% for CAP panels and above regional average scores for all years with NHLS. Quarterly DST scores from WHO-EQA ranged from 78% to 100% in 2010, 80% to 100% in 2011, and 90 to 100% in 2012. From our experience, it is feasible to set-up a BSL-3 TB culture laboratory with acceptable quality performance standards in resource-limited countries. With the demonstrated quality of

  15. Ten-year experience with testicular cancer at a tertiary care hospital in a resource-limited setting: a single centre experience in Tanzania.

    Science.gov (United States)

    Chalya, Phillipo L; Simbila, Samson; Rambau, Peter F

    2014-11-24

    Testicular cancers constitute major therapeutic challenges in resource-limited countries and still carry poor outcomes. There is a paucity of published data regarding testicular cancer in Tanzania, and Bugando Medical Centre in particular. This study describes the clinicopathological pattern, treatment outcome and challenges in the management of testicular cancer in our local setting. This was a retrospective study including all patients who had had histopathologically confirmed testicular cancer at Bugando Medical Centre between February 2004 and January 2014. A total of 56 testicular cancer patients were enrolled in the study, representing 0.9% of all malignancies. The median age of patients at presentation was 28 years, with a peak incidence in the 21-to-30-year age group. A family history of testicular cancer was reported in four (5.4%) patients. A history of cryptorchidism was reported in six (10.7%) patients. Most patients (57.1%) presented late with an advanced stage of cancer. Testicular swelling was the main complaint in 48 (85.7%) patients. The right testis was involved in 67.9% of cases. Lymph node and distant metastases were documented in 10 (17.9%) and 12 (21.4%) patients, respectively. Histologically, 80.4% of patients had germ cell cancers, with seminoma accounting for 62.2% of cases. The most common surgical procedure was inguinal orchidectomy (77.4%). Adjuvant chemotherapy and radiotherapy were used in six (11.1%) and four (7.4%) patients, respectively. Eight (14.3%) patients died. The main predictors of mortality (P65 years), late presentation (>6 months), stage of disease, and presence of metastasis at time of diagnosis. The mean follow-up period was 22 months. At the end of five years, only 18 (37.5%) patients were available for follow-up and the overall 5-year survival rate was 22.2%. The main predictors of 5-year survival rate (PTesticular cancers, though rare in our setting, still carries a poor prognosis. Late presentation, poverty, paucity

  16. Rethinking resources

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, W.L. [Univ. of Texas, Austin, TX (United States)

    1994-09-01

    We class energy and mineral resources as finite because we are reasonably certain that they do not form at a rate remotely approaching man`s rate of use. We have certain environments of the earth that have limits in carrying capacity, and we presume that the global environment does as well. These facts and presumptions, coupled with anxieties over growth in population and consumption, have posed pictures of impending catastrophe from Malthus through the Club of Rome and currently, among certain advocates of what is called sustainable development. To avoid future calamity, command and control management of resource use is urged by many. But, quite simply, such management would presume a wisdom that historical experience suggests does not exist. As a recent example, consider natural gas resources. A decade and a half ago, the resource base of natural gas in the United States was judged to be near exhaustion. Estimates of remaining resources by governmental agencies, academicians, and several major energy companies indicated the ultimate resource would be at about 100 tcf today, with essential depletion by the end of the century. Such was the near universal wisdom that compelled Congress to enact legislation to outright prohibit certain use of natural gas. Today, after nearly eight years of gas supply in excess of demand and with entirely new appreciation of the impact of technology, estimates of the remaining gas resource by industry, government, and others are an order of magnitude greater than those made just 15 yr ago, and the same government that then sought to husband a resource presumed to be near depletion now aggressively promotes its use and consumption. Limits to resources and limits to environmental carrying capacity do indeed exist, but we have yet to define those limits and the paths thereto.

  17. Cost effectiveness of option B plus for prevention of mother-to-child transmission of HIV in resource-limited countries: evidence from Kumasi, Ghana.

    Science.gov (United States)

    VanDeusen, Adam; Paintsil, Elijah; Agyarko-Poku, Thomas; Long, Elisa F

    2015-03-18

    Achieving the goal of eliminating mother-to-child HIV transmission (MTCT) necessitates increased access to antiretroviral therapy (ART) for HIV-infected pregnant women. Option B provides ART through pregnancy and breastfeeding, whereas Option B+ recommends continuous ART regardless of CD4 count, thus potentially reducing MTCT during future pregnancies. Our objective was to compare maternal and pediatric health outcomes and cost-effectiveness of Option B+ versus Option B in Ghana. A decision-analytic model was developed to simulate HIV progression in mothers and transmission (in utero, during birth, or through breastfeeding) to current and all future children. Clinical parameters, including antenatal care access and fertility rates, were estimated from a retrospective review of 817 medical records at two hospitals in Ghana. Additional parameters were obtained from published literature. Modeled outcomes include HIV infections averted among newborn children, quality-adjusted life-years (QALYs), and cost-effectiveness ratios. HIV-infected women in Ghana have a lifetime average of 2.3 children (SD 1.3). Projected maternal life expectancy under Option B+ is 16.1 years, versus 16.0 years with Option B, yielding a gain of 0.1 maternal QALYs and 3.2 additional QALYs per child. Despite higher initial ART costs, Option B+ costs $785/QALY gained, a value considered very cost-effective by World Health Organization benchmarks. Widespread implementation of Option B+ in Ghana could theoretically prevent up to 668 HIV infections among children annually. Cost-effectiveness estimates remained favorable over robust sensitivity analyses. Although more expensive than Option B, Option B+ substantially reduces MTCT in future pregnancies, increases both maternal and pediatric QALYs, and is a cost-effective use of limited resources in Ghana.

  18. Using formative assessment despite the constraints of high stakes testing and limited resources: A case study of chemistry teachers in Anglophone Cameroon

    Science.gov (United States)

    Akom, George Viche

    Formative assessment, as a strategy used to improve student learning, encounters several obstacles in its implementation. This study explores changes in teachers' views and practices as they are introduced to formative assessment in a high stakes testing and limited resource environment. The study examines the extent to which teachers use the technique of formative assessment to engage students in authentic learning even while not sacrificing high test scores on summative assessments. A case study methodology was employed to address the research topic. Science teachers in the West African country of Cameroon were engaged in a process of lesson planning and implementation to collaboratively build lessons with large amounts of formative assessment. Qualitative data from written surveys, group discussions, classroom and workshop observations, and from teacher reflections reveal the extent to which lesson fidelity is preserved from views to planning to implementation. The findings revealed that though the teachers possess knowledge of a variety of assessment methods they do not systematically use these methods to collect information which could help in improving student learning. Oral questioning remained the dominant method of student assessment. The study also showed that the teachers made minimal to big changes depending on the particular aspect of formative assessment being considered. For aspects which needed just behavioral adaptations, the changes were significant but for those which needed acquisition of more pedagogic knowledge and skills the changes were minimal. In terms of constraints in the practice of formative assessment, the teachers cited large class size and lack of teaching materials as common ones. When provided with the opportunity to acquire teaching materials, however, they did not effectively utilize the opportunity. The study revealed a need for the acquisition of inquiry skills by the teachers which can serve as a platform for the