Gene conversion as a secondary mechanism of short interspersed element (SINE) evolution

Energy Technology Data Exchange (ETDEWEB)

Kass, D.H. [Louisiana State Univ. Medical Center, New Orleans, LA (United States). Dept. of Biochemistry and Molecular Biology; Batzer, M.A. [Lawrence Livermore National Lab., CA (United States); Deininger, P.L. [Louisiana State Univ. Medical Center, New Orleans, LA (United States). Dept. of Biochemistry and Molecular Biology]|[Alton Ochsner Medical Foundation, New Orleans, LA (United States). Lab. of Molecular Genetics

1995-01-01

The Alu repetitive family of short interspersed elements (SINEs) in primates can be subdivided into distinct subfamilies by specific diagnostic nucleotide changes. The older subfamilies are generally very abundant, while the younger subfamilies have fewer copies. Some of the youngest Alu elements are absent in the orthologous loci of nonhuman primates, indicative of recent retroposition events, the primary mode of SINE evolutions. PCR analysis of one young Alu subfamily (Sb2) member found in the low-density lipoprotein receptor gene apparently revealed the presence of this element in the green monkey, orangutan, gorilla, and chimpanzee genomes, as well as the human genome. However, sequence analysis of these genomes revealed a highly mutated, older, primate-specific Alu element was present at this position in the nonhuman primates. Comparison of the flanking DNA sequences upstream of this Alu insertion corresponded to evolution expected for standard primate phylogeny, but comparison of the Alu repeat sequences revealed that the human element departed from this phylogeny. The change in the human sequence apparently occurred by a gene conversion event only within the Alu element itself, converting it from one of the oldest to one of the youngest Alu subfamilies. Although gene conversions of Alu elements are clearly very rare, this finding shows that such events can occur and contribute to specific cases of SINE subfamily evolution.

Short notes and reviews Carrying metazoan phylogenetics forward in the 21st century

NARCIS (Netherlands)

Jenner, Ronald A.

2001-01-01

Review of and commentary on: Animal Evolution. Interrelationships of the Living Phyla, by Claus Nielsen. Oxford University Press, 2001, x + 563 pp., ISBN 0-19-850682-1 (Pbk). My initial browsing of the new edition of Claus Nielsen’s Animal Evolution could scarcely have produced a bigger surprise.

Deviation Among Technology Reviews: An Informative Enrichment of Technology Evolution Theory for Marketing

OpenAIRE

Sood, Ashish; Stremersch, Stefan

2010-01-01

textabstractUnderstanding technological change is of critical importance to marketers, as it bears new markets, new brands, new customers, and new market leaders. This paper examines the deviation among reviews of a technology’s performance and its consequences for inferences on technology evolution patterns. The basic premise of the current paper is that technology evolution literature, while highly relevant, is misguided in that it ignores potential deviation among technology reviews. Using...

Creation of point defects in superconductors. A short review

International Nuclear Information System (INIS)

Quere, Yves; Rullier-Albenque, Florence.

1981-11-01

Many experiments have been published concerning the radiation damage in superconductors, but relatively few about the mechanisms of defect creation. A short review is presented of what is known on point defect creation in superconductors either by cold-work or by irradiation

Short wavelength striations on expanding plasma clouds

International Nuclear Information System (INIS)

Winske, D.; Gary, S.P.

1989-01-01

The growth and evolution of short wavelength (< ion gyroradius) flute modes on a plasma expanding across an ambient magnetic field have been actively studied in recent years, both by means of experiments in the laboratory as well as in space and through numerical simulations. We review the relevant observations and simulations results, discuss the instability mechanism and related linear theory, and describe recent work to bring experiments and theory into better agreement. 30 refs., 6 figs

Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America.

Science.gov (United States)

Mitchell, Kieren J; Bray, Sarah C; Bover, Pere; Soibelzon, Leopoldo; Schubert, Blaine W; Prevosti, Francisco; Prieto, Alfredo; Martin, Fabiana; Austin, Jeremy J; Cooper, Alan

2016-04-01

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear (Tremarctos ornatus), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears (Tremarctos), South American short-faced bears (Arctotherium) and North American short-faced bears (Arctodus) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears (Arctodus and Arctotherium), potentially as an adaptation to dominate competition for megafaunal carcasses. © 2016 The Author(s).

A Short Review on Cardiotonic Steroids and Their Aminoguanidine Analogues

Directory of Open Access Journals (Sweden)

Arturo San Feliciano

2000-01-01

Full Text Available A short review on cardiotonic steroids and their analogues is presented. The natural, semisynthetic and synthetic derivatives, as well as their mechanism of action and structure-activity relationships are shown, with a special reference to aminoguanidine derivatives.

Evolution of atherectomy devices.

Science.gov (United States)

Al Khoury, G; Chaer, R

2011-08-01

Percutaneous atherectomy provides an alternative approach to the endovascular treatment of peripheral atherosclerotic occlusive disease beyond angioplasty and stenting, and has the theoretical advantage of lesion debulking and minimizing barotrauma to the vessel wall. Atherectomy has evolved greatly during the last decade, with currently four FDA approved devices for the treatment of peripheral arterial disease. Several reports have focused on the initial technical success rates, and demonstrated the safety and short as well as mid-term efficacy of atherectomy devices. This article will review the evolution of current atherectomy devices and the associated literature.

Priority effects are weakened by a short, but not long, history of sympatric evolution.

Science.gov (United States)

Zee, Peter C; Fukami, Tadashi

2018-01-31

Priority effects, or the effects of species arrival history on local species abundances, have been documented in a range of taxa. However, factors determining the extent to which priority effects affect community assembly remain unclear. Using laboratory populations of the bacterium Pseudomonas fluorescens , we examined whether shared evolutionary history affected the strength of priority effects. We hypothesized that sympatric evolution of populations belonging to the same guild would lead to niche differentiation, resulting in phenotypic complementarity that weakens priority effects. Consistent with this hypothesis, we found that priority effects tended to be weaker in sympatrically evolved pairs of immigrating populations than in allopatrically evolved pairs. Furthermore, priority effects were weaker under higher phenotypic complementarity. However, these patterns were observed only in populations with a relatively short history of sympatric evolution, and disappeared when populations had evolved together for a long time. Together, our results suggest that the evolutionary history of organismal traits may dictate the strength of priority effects and, consequently, the extent of historical contingency in the assembly of ecological communities. © 2018 The Author(s).

Short versus long term benefits and the evolution of cooperation in the prisoner's dilemma game.

Directory of Open Access Journals (Sweden)

Markus Brede

Full Text Available In this paper I investigate the evolution of cooperation in the prisoner's dilemma when individuals change their strategies subject to performance evaluation of their neighbours over variable time horizons. In the monochrome setting, in which all agents per default share the same performance evaluation rule, weighing past events strongly dramatically enhances the prevalence of cooperators. For co-evolutionary models, in which evaluation time horizons and strategies can co-evolve, I demonstrate that cooperation naturally associates with long-term evaluation of others while defection is typically paired with very short time horizons. Moreover, considering the continuous spectrum in between enhanced and discounted weights of past performance, cooperation is optimally supported when cooperators neither give enhanced weight to past nor more recent events, but simply average payoffs. Payoff averaging is also found to emerge as the dominant strategy for cooperators in co-evolutionary models, thus proposing a natural route to the evolution of cooperation in viscous populations.

The Evolution from Traditional to Online Professional Development: A Review

Science.gov (United States)

Elliott, Joshua C.

2017-01-01

Online professional development offers opportunities for growth to teachers who may not be able to participate otherwise due to constraints. These constraints include, but are not limited to, time and travel distance. This document is a narrative review of relevant literature as it relates to the evolution of teacher professional development. This…

The role of short messaging service in supporting the delivery of healthcare: An umbrella systematic review.

Science.gov (United States)

Househ, Mowafa

2016-06-01

Short messaging service (SMS) messages may present a convenient and cost-effective method to support healthcare interventions. This work assesses the effects of short messaging service on various healthcare interventions found in systematic reviews. The search strategy was based on two key concepts: short messaging service and healthcare delivery. The initial search was conducted in December 2012 and was updated in June 2013. Of the 550 identified references, 13 systematic reviews met the inclusion criteria, of which 8 were published in peer-reviewed journals and 5 were retrieved from the Cochrane library. Data analysis shows that low to moderate research evidence exists on the benefits of short messaging service interventions for appointment reminders, promoting health in developing countries and preventive healthcare. In many interventions, however, there were a few studies that were of high quality, and most of the studies were rated from low to moderate quality or had no rating at all. Healthcare organizations, policy makers, or clinicians using short messaging service messages to support healthcare interventions should (1) implement interventions that have been found to work in healthcare settings, (2) continue evaluating short messaging service interventions that have not been adequately assessed, and (3) improve collaboration between various healthcare entities to develop studies targeted at specific populations to evaluate the long-term impact of short messaging service on healthcare outcomes. © The Author(s) 2014.

Short-term genome evolution of Listeria monocytogenes in a non-controlled environment

Directory of Open Access Journals (Sweden)

Ivy Reid A

2008-11-01

outbreak was caused by a L. monocytogenes strain that persisted in a food processing facility over 12 years and show that genome sequencing is a valuable and feasible tool for retrospective epidemiological analyses. Short-term evolution of L. monocytogenes in non-controlled environments appears to involve limited diversification beyond plasmid gain or loss and prophage diversification, highlighting the importance of phages in bacterial evolution.

The evolution of robotic general surgery.

Science.gov (United States)

Wilson, E B

2009-01-01

Surgical robotics in general surgery has a relatively short but very interesting evolution. Just as minimally invasive and laparoscopic techniques have radically changed general surgery and fractionated it into subspecialization, robotic technology is likely to repeat the process of fractionation even further. Though it appears that robotics is growing more quickly in other specialties, the changes digital platforms are causing in the general surgical arena are likely to permanently alter general surgery. This review examines the evolution of robotics in minimally invasive general surgery looking forward to a time where robotics platforms will be fundamental to elective general surgery. Learning curves and adoption techniques are explored. Foregut, hepatobiliary, endocrine, colorectal, and bariatric surgery will be examined as growth areas for robotics, as well as revealing the current uses of this technology.

Comparing Short Dental Implants to Standard Dental Implants: Protocol for a Systematic Review.

Science.gov (United States)

Rokn, Amir Reza; Keshtkar, Abbasali; Monzavi, Abbas; Hashemi, Kazem; Bitaraf, Tahereh

2018-01-18

Short dental implants have been proposed as a simpler, cheaper, and faster alternative for the rehabilitation of atrophic edentulous areas to avoid the disadvantages of surgical techniques for increasing bone volume. This review will compare short implants (4 to 8 mm) to standard implants (larger than 8 mm) in edentulous jaws, evaluating on the basis of marginal bone loss (MBL), survival rate, complications, and prosthesis failure. We will electronically search for randomized controlled trials comparing short dental implants to standard dental implants in the following databases: PubMed, Web of Science, EMBASE, Scopus, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov with English language restrictions. We will manually search the reference lists of relevant reviews and the included articles in this review. The following journals will also be searched: European Journal of Oral Implantology, Clinical Oral Implants Research, and Clinical Implant Dentistry and Related Research. Two reviewers will independently perform the study selection, data extraction and quality assessment (using the Cochrane Collaboration tool) of included studies. All meta-analysis procedures including appropriate effect size combination, sub-group analysis, meta-regression, assessing publication or reporting bias will be performed using Stata (Statacorp, TEXAS) version 12.1. Short implant effectiveness will be assessed using the mean difference of MBL in terms of weighted mean difference (WMD) and standardized mean difference (SMD) using Cohen's method. The combined effect size measures in addition to the related 95% confidence intervals will be estimated by a fixed effect model. The heterogeneity of the related effect size will be assessed using a Q Cochrane test and I2 measure. The MBL will be presented by a standardized mean difference with a 95% confidence interval. The survival rate of implants, prostheses failures, and complications will be reported using a risk

The Evolution of the Concept of Bureaucracy

Directory of Open Access Journals (Sweden)

Ţierean O.

2009-12-01

Full Text Available The first half of the paper defines the concept of bureaucracy, its evolution over the time and the current academic debates. A short review of the most debatable theories written by Lowi, Niskanen, Dunleavy and Choudhury is included. The second half focuses on the three concepts of power put forward by Russel and the non-paid goals bureaucratic offices pursue on a daily basis. The paper also analyses the issue of monitoring the output of bureaucratic offices.

Short fiber-reinforced composite restorations: A review of the current literature.

Science.gov (United States)

Garoushi, Sufyan; Gargoum, Ausama; Vallittu, Pekka K; Lassila, Lippo

2018-02-25

A newly-recommended method for restoring large cavities is the biomimetic approach of using short fiber-reinforced composite (SFRC) as dentine-replacing material. The aim of the current review was to present an overview of SFRC and to give the clinician a detailed understanding of this new material and treatment strategy based on available-literature review. A thorough literature search was done up to December 2017. The range of relevant publications was surveyed using PubMed and Google Scholar. From the search results, articles related to our search terms were only considered. The search terms used were "short fiber-reinforced composite", "everX posterior", and "fiber-reinforced composite restorations". Of the assessed articles selected (N = 70), most were laboratory-based research with various test specimen designs prepared according to the ISO standard or with extracted teeth; only four articles were clinical reports. A common finding was that by combining the SFRC as a bulk base with conventional composite, the load-bearing capacity and failure mode of the material combination were improved, as compared to plain conventional composite restoration. In the reviewed studies, the biomimetic restoration technique of using SFRC showed promising characteristics, and therefore, might be recommended as an alternative treatment option for large cavities. © 2018 John Wiley & Sons Australia, Ltd.

Review of short-lived radionuclide activities in the United States

International Nuclear Information System (INIS)

Sodd, V.J.

1985-01-01

A review is given of the accelerator-produced short-lived radionuclides which are used in radiopharmaceuticals available commercially in the US and of the accelerator facilities devoted primarily to their production. Reactions for the efficient production of 67 Ga, 81 Rb → /sup 81m/Kr, 111 In, 201 Tl, and 123 I are given. Methods for the production of higher purity 123 I are suggested

Short course review and the future

Energy Technology Data Exchange (ETDEWEB)

Corden, Pierce S. [Center for Science, Technology and Security Policy, American Association for the Advancement of Science, Washington, DC 20005 (United States)

2014-05-09

The presentations at the short course that were the basis of the present Proceedings covered many critical issues related to the objective of eliminating nuclear weapons as a means of ensuring global security and stability. This paper is based on the concluding talk, which briefly reviewed the course, offered a net assessment of where the project of elimination - a policy objective for nearly all the world's states - stands, and discussed some of the factors that need to be dealt with in achieving a nuclear weapon free world. These include understanding what 'proliferation' means and how it has changed over time, how the spread of nuclear weapons has proceeded over time, both 'vertical' in numbers and 'horizontal' to additional countries, what way the 'vector' of reversing proliferation is pointing, and the roles of nuclear energy and international governance.

DA Masolo A Short History of African Philosophy, a Review pp165-171

African Journals Online (AJOL)

DA Masolo

Review of Barry Hallen's A Short History of African Philosophy, Second ... 2006, by African Philosophy: The Analytic Approach (Africa World Press). .... handling of culpability in witchcraft accusations as overlooking the obvious logical inference.

Short dental implants: A scoping review of the literature for patients with head and neck cancer.

Science.gov (United States)

Edher, Faraj; Nguyen, Caroline T

2017-09-16

Dental implants can be essential in the rehabilitation of various cancer defects, but their ideal placement can be complicated by the limited dimensions of the available host bone. Surgical interventions developed to increase the amount of bone are not all predictable or successful and can sometimes be contraindicated. Short dental implants have been suggested as an alternative option in sites where longer implants are not possible. Whether they provide a successful treatment option is unclear. The purpose of this study was to review the literature on short dental implants and assess whether they are a viable definitive treatment option for rehabilitating cancer patients with deficient bone. A scoping review of the literature was performed, including a search of established periodontal textbooks for articles on short dental implants combined with a search of PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews. A search for all literature published before June 2016 was based on the following keywords: ['dental implants' OR 'dental implantation, endosseous' OR 'dental prosthesis, implant supported'] AND [short]. The minimum acceptable implant length has been considered to be 6 mm. The survival rates of short implants varied between 74% and 96% at 5 years, depending on factors such as the quality of the patient's bone, primary stability of the implant, clinician's learning curve, and implant surface. Short implants can achieve results similar to those of longer implants in augmented bone and offer a treatment alternative that could reduce the need for invasive surgery and associated morbidity and be safer and more economical. Short dental implants (6 mm to 8 mm) can be used successfully to support single or multiple fixed reconstructions or overdentures in atrophic maxillae and mandibles. The use of short dental implants lessens the need for advanced and complicated surgical bone augmentation procedures, which reduces complications

A review on the young history of the wind power short-term prediction

Energy Technology Data Exchange (ETDEWEB)

Costa, Alexandre; Navarro, Jorge [Wind Energy, Division of Renewable Energies, Department of Energy, CIEMAT, Av. Complutense, 22, Ed. 42, 28044 Madrid (Spain); Crespo, Antonio [Laboratorio de Mecanica de Fluidos, Departmento de Ingenieria Energetica y Fluidomecanica, ETSII, Universidad Politecnica de Madrid, C/Jose Gutierrez Abascal, 2-28006 Madrid (Spain); Lizcano, Gil [Oxford University Centre for the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY (United Kingdom); Madsen, Henrik [Informatics and Mathematical Modelling - IMM, Technical University of Denmark, Richard Petersens Plads, Building 321, Office 019, 2800 Kgs. Lyngby (Denmark); Feitosa, Everaldo [Brazilian Wind Energy Centre - CBEE, Centro de Tecnologia e Geociencias, UFPE-50.740-530 Recife, PE (Brazil)

2008-08-15

This paper makes a brief review on 30 years of history of the wind power short-term prediction, since the first ideas and sketches on the theme to the actual state of the art on models and tools, giving emphasis to the most significant proposals and developments. The two principal lines of thought on short-term prediction (mathematical and physical) are indistinctly treated here and comparisons between models and tools are avoided, mainly because, on the one hand, a standard for a measure of performance is still not adopted and, on the other hand, it is very important that the data are exactly the same in order to compare two models (this fact makes it almost impossible to carry out a quantitative comparison between a huge number of models and methods). In place of a quantitative description, a qualitative approach is preferred for this review, remarking the contribution (and innovative aspect) of each model. On the basis of the review, some topics for future research are pointed out. (author)

Alveolar pulmonary proteinosis: case report and literature review

International Nuclear Information System (INIS)

Vergara, Erika; Saenz, Alberto; Ojeda, Paulina

2009-01-01

We describe the case of a young women with primary alveolar proteinosis, with a short period of symptoms that are uncommon for this disease, without risk factors for this entity, the clinical evolution of the patient and some complications with the treatment. We review the literature for this entity.

Deviation Among Technology Reviews: An Informative Enrichment of Technology Evolution Theory for Marketing

NARCIS (Netherlands)

A. Sood (Ashish); S. Stremersch (Stefan)

2010-01-01

textabstractUnderstanding technological change is of critical importance to marketers, as it bears new markets, new brands, new customers, and new market leaders. This paper examines the deviation among reviews of a technology’s performance and its consequences for inferences on technology evolution

Fuel consumption: short term and long term price impacts per population type

International Nuclear Information System (INIS)

2011-01-01

This report presents assessments of the price sensitivity of household fuel consumption. After a literature review on price-elasticity assessments and the use of pseudo-panels, the investigation analyses the deciding factors of the household fuel expense and its evolution between 1985 and 2006. It proposes a short term price-elasticity assessment based on the most recent survey, and also proposes price-elasticity assessments for sub-populations, notably in terms of income level or location (rural or urban areas)

Short (

NARCIS (Netherlands)

Telleman, Gerdien; den Hartog, Laurens

2013-01-01

Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

The effects of short-lived radionuclides and porosity on the early thermo-mechanical evolution of planetesimals

Science.gov (United States)

Lichtenberg, Tim; Golabek, Gregor J.; Gerya, Taras V.; Meyer, Michael R.

2016-08-01

The thermal history and internal structure of chondritic planetesimals, assembled before the giant impact phase of chaotic growth, potentially yield important implications for the final composition and evolution of terrestrial planets. These parameters critically depend on the internal balance of heating versus cooling, which is mostly determined by the presence of short-lived radionuclides (SLRs), such as 26Al and 60Fe, as well as the heat conductivity of the material. The heating by SLRs depends on their initial abundances, the formation time of the planetesimal and its size. It has been argued that the cooling history is determined by the porosity of the granular material, which undergoes dramatic changes via compaction processes and tends to decrease with time. In this study we assess the influence of these parameters on the thermo-mechanical evolution of young planetesimals with both 2D and 3D simulations. Using the code family I2ELVIS/I3ELVIS we have run numerous 2D and 3D numerical finite-difference fluid dynamic models with varying planetesimal radius, formation time and initial porosity. Our results indicate that powdery materials lowered the threshold for melting and convection in planetesimals, depending on the amount of SLRs present. A subset of planetesimals retained a powdery surface layer which lowered the thermal conductivity and hindered cooling. The effect of initial porosity was small, however, compared to those of planetesimal size and formation time, which dominated the thermo-mechanical evolution and were the primary factors for the onset of melting and differentiation. We comment on the implications of this work concerning the structure and evolution of these planetesimals, as well as their behavior as possible building blocks of terrestrial planets.

Short message service (SMS) as an educational tool during pregnancy : A literature review

NARCIS (Netherlands)

Lamont, Kim; Sliwa, Karen; Stewart, Simon; Carrington, Melinda; Pretorius, Sandra; Libhaber, Elena; Wiysonge, Charles S.; Adebayo, Esther F.; Klipstein-Grobusch, Kerstin

2016-01-01

Background: In many low- and middle-income countries, access to health information during pregnancy is poor. The rapid adoption of mobile phones in these countries has created new opportunities for disseminating such information. Objective: This paper reviews existing information on the use of short

Barley yellow dwarf disease as a target of breeding for resistance (short review

Directory of Open Access Journals (Sweden)

Katarzyna Golnik

2012-12-01

Full Text Available The aim of this work was to give a brief review of some points of wide knowledge of barley yellow dwarf (BYD disease and its breeding for resistance program.Yd2 gene has been shortly characterised. Current situation in Poland has been underlined.

A review on the young history of the wind power short-term prediction

DEFF Research Database (Denmark)

Costa, A.; Crespo, A.; Navarro, J.

2008-01-01

This paper makes a brief review on 30 years of history of the wind power short-term prediction, since the first ideas and sketches on the theme to the actual state of the art oil models and tools, giving emphasis to the most significant proposals and developments. The two principal lines of thought...... on short-term prediction (mathematical and physical) are indistinctly treated here and comparisons between models and tools are avoided, mainly because, on the one hand, a standard for a measure of performance is still not adopted and, on the other hand, it is very important that the data are exactly...

Modeling evolution and immune system by cellular automata

International Nuclear Information System (INIS)

Bezzi, M.

2001-01-01

In this review the behavior of two different biological systems is investigated using cellular automata. Starting from this spatially extended approach it is also tried, in some cases, to reduce the complexity of the system introducing mean-field approximation, and solving (or trying to solve) these simplified systems. It is discussed the biological meaning of the results, the comparison with experimental data (if available) and the different features between spatially extended and mean-field versions. The biological systems considered in this review are the following: Darwinian evolution in simple ecosystems and immune system response. In the first section the main features of molecular evolution are introduced, giving a short survey of genetics for physicists and discussing some models for prebiotic systems and simple ecosystems. It is also introduced a cellular automaton model for studying a set of evolving individuals in a general fitness landscape, considering also the effects of co-evolution. In particular the process of species formation (speciation) is described in sect. 5. The second part deals with immune system modeling. The biological features of immune response are discussed, as well as it is introduced the concept of shape space and of idiotypic network. More detailed reviews which deal with immune system models (mainly focused on idiotypic network models) can be found. Other themes here discussed: the applications of CA to immune system modeling, two complex cellular automata for humoral and cellular immune response. Finally, it is discussed the biological data and the general conclusions are drawn in the last section

DMPD: Function of lipopolysaccharide (LPS)-binding protein (LBP) and CD14, thereceptor for LPS/LBP complexes: a short review. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available eptor for LPS/LBP complexes: a short review. Schumann RR. Res Immunol. 1992 Jan;143(1):11-5. (.png) (.svg) (...ride (LPS)-binding protein (LBP) and CD14, thereceptor for LPS/LBP complexes: a short review. Authors Schuma.../LBP complexes: a short review. PubmedID 1373512 Title Function of lipopolysaccha....html) (.csml) Show Function of lipopolysaccharide (LPS)-binding protein (LBP) and CD14, thereceptor for LPS

The role of second phases for controlling microstructural evolution in polymineralic rocks: A review

DEFF Research Database (Denmark)

Herwegh, Marco; Linckens, Jolien; Ebert, Andreas

2011-01-01

We present a state-of-the-art review of the microstructural evolution in rocks under static and deformational conditions. First, the general concepts and processes are introduced using monomineralic aggregates. Then, they are expanded into the more complex context of polymineralic rocks...... with a dominant matrix phase. The first part of this contribution delivers information on sample strategies to quantify polymineralic microfabrics. Based on comparisons between microfabrics of monomineralic and polymineralic rocks, we use the common knowledge collected over the past decades for monomineralic......, and deformation mechanisms. We speculate on the effect of mineral reactions during the evolution of microstructures and rheology in polymineralic aggregates at different metamorphic conditions. At the end of the article, we demonstrate the great potential of grain-size evolution maps as microstructural tool...

Short- and long-term impact of critical illness on relatives: literature review.

Science.gov (United States)

Paul, Fiona; Rattray, Janice

2008-05-01

This paper is a report of a literature review undertaken to identify the short- and long-term impact of critical illness on relatives. Patients in intensive care can experience physical and psychological consequences, and their relatives may also experience such effects. Although it is recognized that relatives have specific needs, it is not clear whether these needs are always met and whether further support is required, particularly after intensive care. The following databases were searched for the period 1950-2007: Medline, British Nursing Index and Archive, EMBASE, CINAHL, PsycINFO and EMB Reviews--Cochrane Central Register of Clinical Trials. Search terms focused on adult relatives of critically ill adult patients during and after intensive care. Recurrent topics were categorized to structure the review, i.e. 'relatives needs', 'meeting relatives' needs', 'interventions', 'satisfaction', 'psychological outcomes' and 'coping'. Studies have mainly identified relatives' immediate needs using the Critical Care Family Needs Inventory. There are few studies of interventions to meet relatives' needs and the short- and long-term effects of critical illness on relatives. Despite widespread use of the Critical Care Family Needs Inventory, factors such as local or cultural differences may influence relatives' needs. Relatives may also have unidentified needs, and these needs should be explored. Limited research has been carried out into interventions to meet relatives' needs and the effects of critical illness on their well-being, yet some relatives may experience negative psychological consequences far beyond the acute phase of the illness.

Short Message Service (SMS) as an Educational Tool during Pregnancy: A Literature Review

Science.gov (United States)

Lamont, Kim; Sliwa, Karen; Stewart, Simon; Carrington, Melinda; Pretorius, Sandra; Libhaber, Elena; Wiysonge, Charles S.; Adebayo, Esther F.; Klipstein-Grobusch, Kerstin

2016-01-01

Background: In many low- and middle-income countries, access to health information during pregnancy is poor. The rapid adoption of mobile phones in these countries has created new opportunities for disseminating such information. Objective: This paper reviews existing information on the use of short message services (SMSs) as a feasible tool to…

Short-wavelength free-electron laser sources and science: a review

Science.gov (United States)

Seddon, E. A.; Clarke, J. A.; Dunning, D. J.; Masciovecchio, C.; Milne, C. J.; Parmigiani, F.; Rugg, D.; Spence, J. C. H.; Thompson, N. R.; Ueda, K.; Vinko, S. M.; Wark, J. S.; Wurth, W.

2017-11-01

This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime. The aim is to provide newcomers to the area with insights into: the basic physics of FELs, the qualities of the radiation they produce, the challenges of transmitting that radiation to end users and the diversity of current scientific applications. Initial consideration is given to FEL theory in order to provide the foundation for discussion of FEL output properties and the technical challenges of short-wavelength FELs. This is followed by an overview of existing x-ray FEL facilities, future facilities and FEL frontiers. To provide a context for information in the above sections, a detailed comparison of the photon pulse characteristics of FEL sources with those of other sources of high brightness x-rays is made. A brief summary of FEL beamline design and photon diagnostics then precedes an overview of FEL scientific applications. Recent highlights are covered in sections on structural biology, atomic and molecular physics, photochemistry, non-linear spectroscopy, shock physics, solid density plasmas. A short industrial perspective is also included to emphasise potential in this area. Dedicated to John M J Madey (1943-2016) and Rodolfo Bonifacio (1940-2016) whose perception, drive and perseverance paved the way for the realisation and development of short-wavelength free-electron lasers.

Embodied Evolution in Collective Robotics: A Review

Directory of Open Access Journals (Sweden)

Nicolas Bredeche

2018-02-01

Full Text Available This article provides an overview of evolutionary robotics techniques applied to online distributed evolution for robot collectives, namely, embodied evolution. It provides a definition of embodied evolution as well as a thorough description of the underlying concepts and mechanisms. This article also presents a comprehensive summary of research published in the field since its inception around the year 2000, providing various perspectives to identify the major trends. In particular, we identify a shift from considering embodied evolution as a parallel search method within small robot collectives (fewer than 10 robots to embodied evolution as an online distributed learning method for designing collective behaviors in swarm-like collectives. This article concludes with a discussion of applications and open questions, providing a milestone for past and an inspiration for future research.

Effects of external focus of attention on balance: a short review.

Science.gov (United States)

Park, Sun Hee; Yi, Chae Woo; Shin, Ju Yong; Ryu, Young Uk

2015-12-01

[Purpose] The present study reviewed studies that examined the effects of attentional focus on balance. [Methods] Keywords such as "attentional", "focus", and "balance" were used to find relevant research papers in PubMed (www.ncbi.nlm.nih.gov/pubmed). Forty-five papers were found, and 18 of them were used for this study, excluding review papers and papers irrelevant to the topic of this study. [Results] Among the papers used for the review, the number of papers in which external focus produced effective outcomes was 15 (83.3%). The number of papers in which both external and internal focus produced effective outcomes was 2 (11.1%). The number of paper in which no instruction about attentional focus was effective was 1 (5.5%), and the number of papers in which internal focus was effective was zero. [Conclusion] This short review suggests clinical implications about how physical therapists can use attentional focus for balance rehabilitation of patients. Instructions about external focus of attention can generally be useful as a method to improve posture and balance control. Furthermore, the present reviews indicates that external focus of attention would be more useful in a rehabilitation stage in which the difficulty level of balance performance is gradually increased.

The structure and formation of functional hard coatings: a short review

Directory of Open Access Journals (Sweden)

Diciuc Vlad

2017-01-01

Full Text Available Turning tools come in different shapes and sizes, geometry, base material and coating, according to their destination. They are widely used both for obtaining parts and for machinability tests. In this paper a short review about high-speed steel (HSS turning tools and their coatings is presented. Hard coatings formed on the tool material should be functional depending on the tool final application. Requirements for hard coatings and technological problems for layer formation on the real cutting tool are discussed.

A brief description about the evolution of the masticatory complex, its causes and future effects: A review

Directory of Open Access Journals (Sweden)

Imon Pal

2017-01-01

Full Text Available The diversity of mammalian teeth remains a major attraction both scientifically and aesthetically. Bizarre-shaped teeth are a good reminder of both evolutionary flexibility and the precision of the developmental control mechanism. With time and adaptation to changing environments, several changes have occurred over a span of million years. These adaptations resulted in both positive and negative changes. The review article was written after an initial thorough search of both online and offline databases regarding articles related to evolution and craniofacial evolution. All available information related to the field of dentistry was compiled together. Ethical clearance was not necessary due to the nature of the study. This article provides a brief review on the changes in the teeth and jaw over the course of evolution and the factors that triggered it. A question arises whether, keeping the past in mind and seeing the present, we can predict the future changes that might occur in the human dentition.

Evolution of short range order in Ar: Liquid to glass and solid transitions-A computational study

Science.gov (United States)

Shor, Stanislav; Yahel, Eyal; Makov, Guy

2018-04-01

The evolution of the short range order (SRO) as a function of temperature in a Lennard-Jones model liquid with Ar parameters was determined and juxtaposed with thermodynamic and kinetic properties obtained as the liquid was cooled (heated) and transformed between crystalline solid or glassy states and an undercooled liquid. The Lennard-Jones system was studied by non-equilibrium molecular dynamics simulations of large supercells (approximately 20000 atoms) rapidly cooled or heated at selected quenching rates and at constant pressure. The liquid to solid transition was identified by discontinuities in the atomic volume and molar enthalpy; the glass transition temperature range was identified from the temperature dependence of the self-diffusion. The SRO was studied within the quasi-crystalline model (QCM) framework and compared with the Steinhardt bond order parameters. Within the QCM it was found that the SRO evolves from a bcc-like order in the liquid through a bct-like short range order (c/a=1.2) in the supercooled liquid which persists into the glass and finally to a fcc-like ordering in the crystalline solid. The variation of the SRO that results from the QCM compares well with that obtained with Steinhardt's bond order parameters. The hypothesis of icosahedral order in liquids and glasses is not supported by our results.

Short dental implants versus standard dental implants placed in the posterior jaws: A systematic review and meta-analysis.

Science.gov (United States)

Lemos, Cleidiel Aparecido Araujo; Ferro-Alves, Marcio Luiz; Okamoto, Roberta; Mendonça, Marcos Rogério; Pellizzer, Eduardo Piza

2016-04-01

The purpose of the present systematic review and meta-analysis was to compare short implants (equal or less than 8mm) versus standard implants (larger than 8mm) placed in posterior regions of maxilla and mandible, evaluating survival rates of implants, marginal bone loss, complications and prosthesis failures. This review has been registered at PROSPERO under the number CRD42015016588. Main search terms were used in combination: dental implant, short implant, short dental implants, short dental implants posterior, short dental implants maxilla, and short dental implants mandible. An electronic search for data published up until September/2015 was undertaken using the PubMed/Medline, Embase and The Cochrane Library databases. Eligibility criteria included clinical human studies, randomized controlled trials and/or prospective studies, which evaluated short implants in comparison to standard implants in the same study. The search identified 1460 references, after inclusion criteria 13 studies were assessed for eligibility. A total of 1269 patients, who had received a total of 2631 dental implants. The results showed that there was no significant difference of implants survival (P=.24; RR:1.35; CI: 0.82-2.22), marginal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00), complications (P=.08; RR:0.54; CI: 0.27-1.09) and prosthesis failures (P=.92; RR:0.96; CI: 0.44-2.09). Short implants are considered a predictable treatment for posterior jaws. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks to failures compared to standard implants. Short implants are frequently placed in the posterior area in order to avoid complementary surgical procedures. However, clinicians need to be aware that short implants with length less than 8mm present greater risk of failures. Copyright © 2016. Published by Elsevier Ltd.

Applications of Electrical Impedance Tomography (EIT): A Short Review

Science.gov (United States)

Kanti Bera, Tushar

2018-03-01

Electrical Impedance Tomography (EIT) is a tomographic imaging method which solves an ill posed inverse problem using the boundary voltage-current data collected from the surface of the object under test. Though the spatial resolution is comparatively low compared to conventional tomographic imaging modalities, due to several advantages EIT has been studied for a number of applications such as medical imaging, material engineering, civil engineering, biotechnology, chemical engineering, MEMS and other fields of engineering and applied sciences. In this paper, the applications of EIT have been reviewed and presented as a short summary. The working principal, instrumentation and advantages are briefly discussed followed by a detail discussion on the applications of EIT technology in different areas of engineering, technology and applied sciences.

Animal evolution

DEFF Research Database (Denmark)

Nielsen, Claus

This book provides a comprehensive analysis of evolution in the animal kingdom. It reviews the classical, morphological information from structure and embryology, as well as the new data gained from studies using immune stainings of nerves and muscles and blastomere markings, which makes it possi......This book provides a comprehensive analysis of evolution in the animal kingdom. It reviews the classical, morphological information from structure and embryology, as well as the new data gained from studies using immune stainings of nerves and muscles and blastomere markings, which makes...

Evolution of microstructure in face centered cubic metals during irradiation: A review

International Nuclear Information System (INIS)

Garner, F.A.

1993-06-01

When fcc metals and alloys are irradiated at elevated temperatures, they tend to evolve toward saturation microstructures that are independent of the starting state of the metal and the early details of irradiation history. This leads to property changes and rates of dimensional change that also eventually become independent of the starting state. The evolution of microstructure in complex alloys, especially during the transient regime, is usually determined by the complex interaction of many microstructural and microchemical processes. The more complex the alloy, the more difficult it is to-identify and define the separate influence of each participating mechanism. The use of irradiation studies conducted on simple metals or model alloys assists in understanding the behavior of alloys of engineering relevance. A review of such studies shows that a number of prevailing perceptions of radiation-induced microstructural evolution are not universally correct

The evolution of automation and robotics in manned spaceflight

Science.gov (United States)

Moser, T. L.; Erickson, J. D.

1986-01-01

The evolution of automation on all manned spacecraft including the Space Shuttle is reviewed, and a concept for increasing automation and robotics from the current Shuttle Remote Manipulator System (RMS) to an autonomous system is presented. The requirements for robotic elements are identified for various functions on the Space Station, including extravehicular functions and functions within laboratory and habitation modules which expand man's capacity in space and allow selected teleoperation from the ground. The initial Space Station will employ a telerobot and necessary knowledge based systems as an advisory to the crew on monitoring, fault diagnosis, and short term planning and scheduling.

Catapults fall short

Science.gov (United States)

Gibson, Marcus

2018-01-01

In reply to the news story "UK Catapults fall short, claims review of technology centres", which describes an independent review that criticized the management of the UK's network of technology innovation centres.

Short-Range Noncontact Sensors for Healthcare and Other Emerging Applications: A Review

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Changzhan Gu

2016-07-01

Full Text Available Short-range noncontact sensors are capable of remotely detecting the precise movements of the subjects or wirelessly estimating the distance from the sensor to the subject. They find wide applications in our day lives such as noncontact vital sign detection of heart beat and respiration, sleep monitoring, occupancy sensing, and gesture sensing. In recent years, short-range noncontact sensors are attracting more and more efforts from both academia and industry due to their vast applications. Compared to other radar architectures such as pulse radar and frequency-modulated continuous-wave (FMCW radar, Doppler radar is gaining more popularity in terms of system integration and low-power operation. This paper reviews the recent technical advances in Doppler radars for healthcare applications, including system hardware improvement, digital signal processing, and chip integration. This paper also discusses the hybrid FMCW-interferometry radars and the emerging applications and the future trends.

SHORT LITERATURE REVIEW ON THE KINEMATICS AND DYNAMICS OF THE INDUSTRIAL ROBOTS

OpenAIRE

RATIU Mariana

2016-01-01

This paper is the result of a short literature review on the kinematics and dynamics of the industrial robots, a first study conducted in a wider research that will be further developed in the field of the trajectory generating mechanisms of the industrial robots. After an introduction about the importance of the robots in the industrial processes and about the necessity to streamline and optimize the robot`s motion, are presented some recent approaches related to the kinematic and dynamic an...

The evolutive aspect of the short jat substituents following the sonant r - a comparison between the Serbian literary language and the dialect of Vuk’s ancestors

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Ostojić Vladimir B.

2015-01-01

Full Text Available The paper discusses the evolutive aspects of short “jat” following the sonant r usage during the formation of the modern Serbian literary language and its treatment in the Serbo-Croatistic and the Serbistic descriptive and normative literature. In addition to the basic issue of the distribution of the short “jat’s” substituent following the sonant r in dialects of Montenegro, particularly in the native dialect of Vuk Karadžić’s ancestors, the author also addresses the question related to the mechanisms that cause short “jat” following the sonant r in ijekavian dialects to be reduced sometimes to e, and sometimes to je. Substitution of short “jat” following the sonant r in Jezera-Šarani dialect had important evolution from the times of “classical Vukovian ijekavism”. In this dialect, forms with rje do not occur, except in the word starješina. Here, r and j remained in the same syllable, which set the stage for iotization and depalatalization. The analysis of the paper describes the situation in Jezera-Šarani dialect as well as the situation in other Montenegrian dialects of the older and newer Eastern-Herzegovian type. The author as well takes into consideration that our Pravopis has already disregarded the Vukovian tradition with omitting j that follows sonant r in the examples pogreška and greška. In order to eliminate the disunity, the author concludes that the status of the group re should not be questioned from the aspect of literary language standards.

Musical emotions: Functions, origins, evolution

Science.gov (United States)

Perlovsky, Leonid

2010-03-01

Theories of music origins and the role of musical emotions in the mind are reviewed. Most existing theories contradict each other, and cannot explain mechanisms or roles of musical emotions in workings of the mind, nor evolutionary reasons for music origins. Music seems to be an enigma. Nevertheless, a synthesis of cognitive science and mathematical models of the mind has been proposed describing a fundamental role of music in the functioning and evolution of the mind, consciousness, and cultures. The review considers ancient theories of music as well as contemporary theories advanced by leading authors in this field. It addresses one hypothesis that promises to unify the field and proposes a theory of musical origin based on a fundamental role of music in cognition and evolution of consciousness and culture. We consider a split in the vocalizations of proto-humans into two types: one less emotional and more concretely-semantic, evolving into language, and the other preserving emotional connections along with semantic ambiguity, evolving into music. The proposed hypothesis departs from other theories in considering specific mechanisms of the mind-brain, which required the evolution of music parallel with the evolution of cultures and languages. Arguments are reviewed that the evolution of language toward becoming the semantically powerful tool of today required emancipation from emotional encumbrances. The opposite, no less powerful mechanisms required a compensatory evolution of music toward more differentiated and refined emotionality. The need for refined music in the process of cultural evolution is grounded in fundamental mechanisms of the mind. This is why today's human mind and cultures cannot exist without today's music. The reviewed hypothesis gives a basis for future analysis of why different evolutionary paths of languages were paralleled by different evolutionary paths of music. Approaches toward experimental verification of this hypothesis in

Review of short-term screening tests for mutagens, toxigens, and carcinogens

Energy Technology Data Exchange (ETDEWEB)

Carney, H.J.; Hass, B.S.

1979-07-01

In order to test the thousands of man-made chemicals in the environment for carcinogenic and genetic hazards, a multitude of short-term screening tests has been developed to complement long-term mammalian bioassays and epidemiological studies. These tests cover a broad spectrum of organisms, and include the use of naked and viral nucleic acids, bacteria, fungi, higher plants, insects in vitro mammalian cell cultures (cell transformation, cell-mediated mutagenesis, DNA repair, and chromosome aberration tests) and live mammals. Assay end points include effects on nucleic acids, DNA repair synthesis, point or gene mutation, structural and numerical chromosome aberrations, cytological alterations, and in vitro cell transformation. The present review describes and compares these assays. In addition, it discusses their historical development, the problems and limitations associated with their use, and their implementation in comprehensive testing programs. It is intended to provide overview and specific information to the laboratory that is in the process of establishing genetic toxicological systems. (The literature is reviewed to January 1978.)

Evolution of learning strategies in temporally and spatially variable environments: a review of theory.

Science.gov (United States)

Aoki, Kenichi; Feldman, Marcus W

2014-02-01

The theoretical literature from 1985 to the present on the evolution of learning strategies in variable environments is reviewed, with the focus on deterministic dynamical models that are amenable to local stability analysis, and on deterministic models yielding evolutionarily stable strategies. Individual learning, unbiased and biased social learning, mixed learning, and learning schedules are considered. A rapidly changing environment or frequent migration in a spatially heterogeneous environment favors individual learning over unbiased social learning. However, results are not so straightforward in the context of learning schedules or when biases in social learning are introduced. The three major methods of modeling temporal environmental change--coevolutionary, two-timescale, and information decay--are compared and shown to sometimes yield contradictory results. The so-called Rogers' paradox is inherent in the two-timescale method as originally applied to the evolution of pure strategies, but is often eliminated when the other methods are used. Moreover, Rogers' paradox is not observed for the mixed learning strategies and learning schedules that we review. We believe that further theoretical work is necessary on learning schedules and biased social learning, based on models that are logically consistent and empirically pertinent. Copyright © 2013 Elsevier Inc. All rights reserved.

Evolution of learning strategies in temporally and spatially variable environments: A review of theory

Science.gov (United States)

Aoki, Kenichi; Feldman, Marcus W.

2013-01-01

The theoretical literature from 1985 to the present on the evolution of learning strategies in variable environments is reviewed, with the focus on deterministic dynamical models that are amenable to local stability analysis, and on deterministic models yielding evolutionarily stable strategies. Individual learning, unbiased and biased social learning, mixed learning, and learning schedules are considered. A rapidly changing environment or frequent migration in a spatially heterogeneous environment favors individual learning over unbiased social learning. However, results are not so straightforward in the context of learning schedules or when biases in social learning are introduced. The three major methods of modeling temporal environmental change – coevolutionary, two-timescale, and information decay – are compared and shown to sometimes yield contradictory results. The so-called Rogers’ paradox is inherent in the two-timescale method as originally applied to the evolution of pure strategies, but is often eliminated when the other methods are used. Moreover, Rogers’ paradox is not observed for the mixed learning strategies and learning schedules that we review. We believe that further theoretical work is necessary on learning schedules and biased social learning, based on models that are logically consistent and empirically pertinent. PMID:24211681

Fostering Psychiatry in Ghana: The Impact of a Short Review Course through an International Collaboration

Science.gov (United States)

Laugharne, Jonathan; Appiah-Poku, John; Laugharne, Richard; Stanley, Susanne

2011-01-01

Objective: The aim of the current study was to evaluate a short review course in psychiatry conducted at the Kwame Nkrumah University of Science and Technology medical school and any change in student interest in a career in psychiatry. Method: Students were asked to complete a general psychiatric knowledge questionnaire before and immediately…

Mini-review: Strategies for Variation and Evolution of Bacterial Antigens

Science.gov (United States)

Foley, Janet

2015-01-01

Across the eubacteria, antigenic variation has emerged as a strategy to evade host immunity. However, phenotypic variation in some of these antigens also allows the bacteria to exploit variable host niches as well. The specific mechanisms are not shared-derived characters although there is considerable convergent evolution and numerous commonalities reflecting considerations of natural selection and biochemical restraints. Unlike in viruses, mechanisms of antigenic variation in most bacteria involve larger DNA movement such as gene conversion or DNA rearrangement, although some antigens vary due to point mutations or modified transcriptional regulation. The convergent evolution that promotes antigenic variation integrates various evolutionary forces: these include mutations underlying variant production; drift which could remove alleles especially early in infection or during life history phases in arthropod vectors (when the bacterial population size goes through a bottleneck); selection not only for any particular variant but also for the mechanism for the production of variants (i.e., selection for mutability); and overcoming negative selection against variant production. This review highlights the complexities of drivers of antigenic variation, in particular extending evaluation beyond the commonly cited theory of immune evasion. A deeper understanding of the diversity of purpose and mechanisms of antigenic variation in bacteria will contribute to greater insight into bacterial pathogenesis, ecology and coevolution with hosts. PMID:26288700

Chemical Evolution and the Evolutionary Definition of Life.

Science.gov (United States)

Higgs, Paul G

2017-06-01

Darwinian evolution requires a mechanism for generation of diversity in a population, and selective differences between individuals that influence reproduction. In biology, diversity is generated by mutations and selective differences arise because of the encoded functions of the sequences (e.g., ribozymes or proteins). Here, I draw attention to a process that I will call chemical evolution, in which the diversity is generated by random chemical synthesis instead of (or in addition to) mutation, and selection acts on physicochemical properties, such as hydrolysis, photolysis, solubility, or surface binding. Chemical evolution applies to short oligonucleotides that can be generated by random polymerization, as well as by template-directed replication, and which may be too short to encode a specific function. Chemical evolution is an important stage on the pathway to life, between the stage of "just chemistry" and the stage of full biological evolution. A mathematical model is presented here that illustrates the differences between these three stages. Chemical evolution leads to much larger differences in molecular concentrations than can be achieved by selection without replication. However, chemical evolution is not open-ended, unlike biological evolution. The ability to undergo Darwinian evolution is often considered to be a defining feature of life. Here, I argue that chemical evolution, although Darwinian, does not quite constitute life, and that a good place to put the conceptual boundary between non-life and life is between chemical and biological evolution.

Short Review on Predicting Fouling in RO Desalination

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Alejandro Ruiz-García

2017-10-01

Full Text Available Reverse Osmosis (RO membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered.

Differential diagnosis of CNS angiostrongyliasis: a short review.

Science.gov (United States)

Senthong, Vichai; Chindaprasirt, Jarin; Sawanyawisuth, Kittisak

2013-06-01

The diagnostic criterion for eosinophilic meningitis (EOM) is the identification of an absolute count of 10 eosinophils per ml or more than 10% of the total white blood cells in the cerebrospinal fluid (CSF) in the proper clinical context. The most common cause of EOM is Angiostrongylus cantonensis infection, termed meningitic angiostrongyliasis (MA). Neurognathostomiasis (NG) is the main parasitic disease in the differential diagnosis of meningitic angiostrongyliasis. This short review is based on articles published on Medline between 2000 and 2012 related to EOM. There are three main approaches that can be used to differentiate between MA and NG, involving clinical factors, history of larval exposure, and serological tests. MA patients presented with acute severe headache but without neurological deficit, combined with a history of eating uncooked snails or slugs. NG patients always presented with motor weakness, migratory swelling, radicular pain and had history of eating uncooked poultry or fish. Specific antigenic bands in immunoblot tests are helpful tools to differentiate the two diseases. Other causes of eosinophilic meningitis are neurocysticercosis, cerebral paragonimiasis, Toxoplasma canis, Baylisascaris, tuberculous meningitis, and cryptococcal meningitis.

Correlated evolution of short wavelength sensitive photoreceptor sensitivity and color pattern in Lake Malawi cichlids

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Michael J. Pauers

2016-02-01

Full Text Available For evolutionary ecologists, the holy grail of visual ecology is to establish an unambiguous link between photoreceptor sensitivity, the spectral environment, and the perception of specific visual stimuli (e.g., mates, food, predators, etc.. Due to the bright nuptial colors of the males, and the role female mate choice plays in their evolution, the haplochromine cichlid fishes of the African great lakes are favorite research subjects for such investigations. Despite this attention, current evidence is equivocal; while distinct correlations among photoreceptor sensitivity, photic environment, and male coloration exist in Lake Victorian haplochromines, attempts to find such correlations in Lake Malawian cichlids have failed. Lake Malawi haplochromines have a wide variability in their short-wavelength-sensitive photoreceptors, especially compared to their mid- and long-wavelength-sensitive photoreceptors; these cichlids also vary in the degree to which they express one of three basic color patterns (vertical bars, horizontal stripes, and solid patches of colors, each of which is likely used in a different form of communication. Thus, we hypothesize that, in these fishes, spectral sensitivity and color pattern have evolved in a correlated fashion to maximize visual communication; specifically, ultraviolet sensitivity should be found in vertically-barred species to promote ‘private’ communication, while striped species should be less likely to have ultraviolet sensitivity, since their color pattern carries ‘public’ information. Using phylogenetic independent contrasts, we found that barred species had strong sensitivity to ultraviolet wavelengths, but that striped species typically lacked sensitivity to ultraviolet light. Further, the only variable, even when environmental variables were simultaneously considered, that could predict ultraviolet sensitivity was color pattern. We also found that, using models of correlated evolution, color

Adaptability and evolution.

Science.gov (United States)

Bateson, Patrick

2017-10-06

The capacity of organisms to respond in their own lifetimes to new challenges in their environments probably appeared early in biological evolution. At present few studies have shown how such adaptability could influence the inherited characteristics of an organism's descendants. In part, this has been because organisms have been treated as passive in evolution. Nevertheless, their effects on biological evolution are likely to have been important and, when they occurred, accelerated the pace of evolution. Ways in which this might have happened have been suggested many times since the 1870s. I review these proposals and discuss their relevance to modern thought.

Multi-objective differential evolution with adaptive Cauchy mutation for short-term multi-objective optimal hydro-thermal scheduling

Energy Technology Data Exchange (ETDEWEB)

Qin Hui [College of Hydropower and Information Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhou Jianzhong, E-mail: jz.zhou@hust.edu.c [College of Hydropower and Information Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu Youlin; Wang Ying; Zhang Yongchuan [College of Hydropower and Information Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-04-15

A new multi-objective optimization method based on differential evolution with adaptive Cauchy mutation (MODE-ACM) is presented to solve short-term multi-objective optimal hydro-thermal scheduling (MOOHS) problem. Besides fuel cost, the pollutant gas emission is also optimized as an objective. The water transport delay between connected reservoirs and the effect of valve-point loading of thermal units are also taken into account in the presented problem formulation. The proposed algorithm adopts an elitist archive to retain non-dominated solutions obtained during the evolutionary process. It modifies the DE's operators to make it suit for multi-objective optimization (MOO) problems and improve its performance. Furthermore, to avoid premature convergence, an adaptive Cauchy mutation is proposed to preserve the diversity of population. An effective constraints handling method is utilized to handle the complex equality and inequality constraints. The effectiveness of the proposed algorithm is tested on a hydro-thermal system consisting of four cascaded hydro plants and three thermal units. The results obtained by MODE-ACM are compared with several previous studies. It is found that the results obtained by MODE-ACM are superior in terms of fuel cost as well as emission output, consuming a shorter time. Thus it can be a viable alternative to generate optimal trade-offs for short-term MOOHS problem.

When climate twitches, evolution takes great leaps

International Nuclear Information System (INIS)

Kerr, R.A.

1992-01-01

Earth's climate system has ridden a slow roller coaster for the past 60 million years. It warmed gradually until about 53 million years ago, reaching a peak that brought crocodiles to northern Canada; then it entered a long, undulating downgrade toward the ice-age world of the past few million years. Because the same span of time brought major evolutionary changes, including the rise of modern mammals, paleontologists have long assumed that these slow temperature changes helped spur the processes of evolution. But recent findings have suggested that another, more potent mechanisms was also at work: Abrupt climate excursions, superimposed on these long-term trends, have now been linked to rapid periods of mammal evolution. The evidence for short, sharp evolutionary shocks comes from studies of a pair of mirror-image climate shifts at opposite ends of the Eocene epoch, 55 million and 33.5 million years ago. In both cases, researchers studying the record of climate preserved in sea-floor sediments have found that a gradual climate change-warming in the first case, cooling in the second - suddenly steepened into a short-lived pulse of extreme warming or cooling. The short time scale of these events and their clear coincidence with turning points in the evolution of mammals are providing the tightest links yet between global climate change and evolution on land

Short Review: Cu Catalyst for Autothermal Reforming Methanol for Hydrogen Production

Directory of Open Access Journals (Sweden)

Ho-Shing Wu

2012-06-01

Full Text Available Hydrogen is a promising alternative energy sources, hydrogen can be used in fuel cell applications to pro-ducing electrical energy and water as byproduct. Therefore, fuel cell is a simple application and environ-mentally friendly oriented technology. Recent years various methods have been conducted to produce hy-drogen. Those methods are derived from various sources such as methanol, ethanol, gasoline, hydrocarbons. This article presents a brief review a parameter process of that affects in autothermal reforming methanol use Cu-based catalysts for production of hydrogen. Copyright © 2012 BCREC UNDIP. All rights reserved.Received: 3rd January 2012; Revised: 23rd February 2012; Accepted: 28th February 2012[How to Cite: H.S. Wu, and D. Lesmana. (2012. Short Review: Cu Catalyst for Autothermal Reforming Methanol for Hydrogen Production. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 27-42. doi:10.9767/bcrec.7.1.1284.27-42][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1284.27-42 ] | View in 

International short-term medical missions: a systematic review of recommended practices.

Science.gov (United States)

Roche, Stephanie D; Ketheeswaran, Pavinarmatha; Wirtz, Veronika J

2017-01-01

To identify practices for conducting international short-term medical missions (STMMs) recommended in the literature and examine how these link STMMs to recipient countries' existing health systems. Systematic review of PubMed-indexed articles on STMMs and their bibliographies using preferred reporting items for systematic reviews and meta-analyses guidelines. Recommendations were organized using the World Health Organization Health Systems Framework. In 92 publications, 67 % offered at least one recommendation that would link STMMs to the recipient country's health system. Among these recommendations, most focused on service delivery and few on health financing and governance. There is a lack of consensus around a proper standard of care, patient selection, and trip duration. Comprehensive global standards are needed for STMM work to ensure that services are beneficial both to patients and to the broader healthcare systems of recipient countries. By providing an overview of the current recommendations and important gaps where practice recommendations are needed, this study can provide relevant input into the development of global standards for STMMs.

A numerical study of lowest-order short-crested water wave instabilities

DEFF Research Database (Denmark)

Fuhrman, David R.; Madsen, Per A.

2005-01-01

This work presents the first numerical simulations of the long-term evolution of doubly-periodic short-crested wave instabilities, which are the simplest cases involving the three-dimensional instability of genuinely three-dimensional progressive water waves. The simulated evolutions reveal quali...

The evolution of headache from childhood to adulthood: a review of the literature

Science.gov (United States)

2014-01-01

Headache is one of the most common disorders in childhood, with an estimated 75% of children reporting significant headache by the age of 15 years. Pediatric migraine is the most frequent recurrent headache disorder, occurring in up to 28% of older teenagers. Headaches rank third among the illness-related causes of school absenteeism and result in substantial psychosocial impairment among pediatric patients. The aim of this study was to clarify the evolution of the clinical features of primary headache in the transition from childhood to adulthood through a review of relevant data available in the PubMed and Google Scholar databases for the period 1988 to July 2013. The search strategy identified 15 published articles which were considered eligible for inclusion in the analysis (i.e. relevant to the investigation of pediatric headache outcome). All were carried out after the publication of the first version of the International Classification of Headache Disorders (ICHD-I). The availability of data on the evolution of primary headaches over a period of time is important from both a clinical and a public health perspective. The identification of prognostic factors of the evolution of headache (remission or evolution into another headache form) over time should be an objective of future headache research for the development of prevention strategies. Given that headache is a major factor contributing to school absenteeism and poorer quality of life not only in childhood but also in adolescence, understanding the natural history and the management of the different headache forms is vital for our future. PMID:24641507

The evolution of headache from childhood to adulthood: a review of the literature.

Science.gov (United States)

Antonaci, Fabio; Voiticovschi-Iosob, Cristina; Di Stefano, Anna Luisia; Galli, Federica; Ozge, Aynur; Balottin, Umberto

2014-03-18

Headache is one of the most common disorders in childhood, with an estimated 75% of children reporting significant headache by the age of 15 years. Pediatric migraine is the most frequent recurrent headache disorder, occurring in up to 28% of older teenagers. Headaches rank third among the illness-related causes of school absenteeism and result in substantial psychosocial impairment among pediatric patients. The aim of this study was to clarify the evolution of the clinical features of primary headache in the transition from childhood to adulthood through a review of relevant data available in the PubMed and Google Scholar databases for the period 1988 to July 2013.The search strategy identified 15 published articles which were considered eligible for inclusion in the analysis (i.e., relevant to the investigation of pediatric headache outcome). All were carried out after the publication of the first version of the International Classification of Headache Disorders (ICHD-I). The availability of data on the evolution of primary headaches over a period of time is important from both a clinical and a public health perspective. The identification of prognostic factors of the evolution of headache (remission or evolution into another headache form) over time should be an objective of future headache research for the development of prevention strategies. Given that headache is a major factor contributing to school absenteeism and poorer quality of life not only in childhood but also in adolescence, understanding the natural history and the management of the different headache forms is vital for our future.

SHORT LITERATURE REVIEW ON THE KINEMATICS AND DYNAMICS OF THE INDUSTRIAL ROBOTS

Directory of Open Access Journals (Sweden)

RATIU Mariana

2016-09-01

Full Text Available This paper is the result of a short literature review on the kinematics and dynamics of the industrial robots, a first study conducted in a wider research that will be further developed in the field of the trajectory generating mechanisms of the industrial robots. After an introduction about the importance of the robots in the industrial processes and about the necessity to streamline and optimize the robot`s motion, are presented some recent approaches related to the kinematic and dynamic analysis, the optimization of the robot`s motion, and modeling of the trajectory generating mechanism of the industrial robots.

Language and Verbal Short-Term Memory Skills in Children with Down Syndrome: A Meta-Analytic Review

Science.gov (United States)

Naess, Kari-Anne B.; Lyster, Solveig-Alma Halaas; Hulme, Charles; Melby-Lervag, Monica

2011-01-01

This study presents a meta-analytic review of language and verbal short-term memory skills in children with Down syndrome. The study examines the profile of strengths and weaknesses in children with Down syndrome compared to typically developing children matched for nonverbal mental age. The findings show that children with Down syndrome have…

Teaching genetics prior to teaching evolution improves evolution understanding but not acceptance

Science.gov (United States)

Mead, Rebecca; Hejmadi, Momna

2017-01-01

What is the best way to teach evolution? As microevolution may be configured as a branch of genetics, it being a short conceptual leap from understanding the concepts of mutation and alleles (i.e., genetics) to allele frequency change (i.e., evolution), we hypothesised that learning genetics prior to evolution might improve student understanding of evolution. In the UK, genetics and evolution are typically taught to 14- to 16-y-old secondary school students as separate topics with few links, in no particular order and sometimes with a large time span between. Here, then, we report the results of a large trial into teaching order of evolution and genetics. We modified extant questionnaires to ascertain students’ understanding of evolution and genetics along with acceptance of evolution. Students were assessed prior to teaching, immediately post teaching and again after several months. Teachers were not instructed what to teach, just to teach in a given order. Regardless of order, teaching increased understanding and acceptance, with robust signs of longer-term retention. Importantly, teaching genetics before teaching evolution has a significant (p Teaching genetics first additionally had positive effects on genetics understanding, by increasing knowledge. These results suggest a simple, minimally disruptive, zero-cost intervention to improve evolution understanding: teach genetics first. This same alteration does not, however, result in a significantly increased acceptance of evolution, which reflects a weak correlation between knowledge and acceptance of evolution. Qualitative focus group data highlights the role of authority figures in determination of acceptance. PMID:28542179

Teaching genetics prior to teaching evolution improves evolution understanding but not acceptance.

Science.gov (United States)

Mead, Rebecca; Hejmadi, Momna; Hurst, Laurence D

2017-05-01

What is the best way to teach evolution? As microevolution may be configured as a branch of genetics, it being a short conceptual leap from understanding the concepts of mutation and alleles (i.e., genetics) to allele frequency change (i.e., evolution), we hypothesised that learning genetics prior to evolution might improve student understanding of evolution. In the UK, genetics and evolution are typically taught to 14- to 16-y-old secondary school students as separate topics with few links, in no particular order and sometimes with a large time span between. Here, then, we report the results of a large trial into teaching order of evolution and genetics. We modified extant questionnaires to ascertain students' understanding of evolution and genetics along with acceptance of evolution. Students were assessed prior to teaching, immediately post teaching and again after several months. Teachers were not instructed what to teach, just to teach in a given order. Regardless of order, teaching increased understanding and acceptance, with robust signs of longer-term retention. Importantly, teaching genetics before teaching evolution has a significant (p genetics was taught first. Teaching genetics first additionally had positive effects on genetics understanding, by increasing knowledge. These results suggest a simple, minimally disruptive, zero-cost intervention to improve evolution understanding: teach genetics first. This same alteration does not, however, result in a significantly increased acceptance of evolution, which reflects a weak correlation between knowledge and acceptance of evolution. Qualitative focus group data highlights the role of authority figures in determination of acceptance.

[Human origin and evolution. A review of advances in paleoanthropology, comparative genetics, and evolutionary psychology].

Science.gov (United States)

Markov, A V

2009-01-01

In his main work, "On the origin of species", Darwin has refrained from discusion of the origin of man; be only mentioned that his theory would "throw light" on this problem. This famous Darwin's phrase turned out to be one of the most succesful scientific predictions. In the present paper some of the most important recent adavnces in paleoanthroplogy, comparative genetics and evolutionary psychology are reviewed. These three disciplines currently contribute most to our knowledge of anthropogenesis. The review demonstrates that Darwin's ideas not only "threw light" on human origin and evolution; they provided a comprehensive framework for a great variety of studies concerning different aspects of anthropogenesis.

The Evolution of Musicality: What Can Be Learned from Language Evolution Research?

Science.gov (United States)

Ravignani, Andrea; Thompson, Bill; Filippi, Piera

2018-01-01

Language and music share many commonalities, both as natural phenomena and as subjects of intellectual inquiry. Rather than exhaustively reviewing these connections, we focus on potential cross-pollination of methodological inquiries and attitudes. We highlight areas in which scholarship on the evolution of language may inform the evolution of music. We focus on the value of coupled empirical and formal methodologies, and on the futility of mysterianism , the declining view that the nature, origins and evolution of language cannot be addressed empirically. We identify key areas in which the evolution of language as a discipline has flourished historically, and suggest ways in which these advances can be integrated into the study of the evolution of music.

The Evolution of Musicality: What Can Be Learned from Language Evolution Research?

Directory of Open Access Journals (Sweden)

Andrea Ravignani

2018-02-01

Full Text Available Language and music share many commonalities, both as natural phenomena and as subjects of intellectual inquiry. Rather than exhaustively reviewing these connections, we focus on potential cross-pollination of methodological inquiries and attitudes. We highlight areas in which scholarship on the evolution of language may inform the evolution of music. We focus on the value of coupled empirical and formal methodologies, and on the futility of mysterianism, the declining view that the nature, origins and evolution of language cannot be addressed empirically. We identify key areas in which the evolution of language as a discipline has flourished historically, and suggest ways in which these advances can be integrated into the study of the evolution of music.

Global change and the evolution of phenotypic plasticity in plants.

Science.gov (United States)

Matesanz, Silvia; Gianoli, Ernesto; Valladares, Fernando

2010-09-01

Global change drivers create new environmental scenarios and selective pressures, affecting plant species in various interacting ways. Plants respond with changes in phenology, physiology, and reproduction, with consequences for biotic interactions and community composition. We review information on phenotypic plasticity, a primary means by which plants cope with global change scenarios, recommending promising approaches for investigating the evolution of plasticity and describing constraints to its evolution. We discuss the important but largely ignored role of phenotypic plasticity in range shifts and review the extensive literature on invasive species as models of evolutionary change in novel environments. Plasticity can play a role both in the short-term response of plant populations to global change as well as in their long-term fate through the maintenance of genetic variation. In new environmental conditions, plasticity of certain functional traits may be beneficial (i.e., the plastic response is accompanied by a fitness advantage) and thus selected for. Plasticity can also be relevant in the establishment and persistence of plants in novel environments that are crucial for populations at the colonizing edge in range shifts induced by climate change. Experimental studies show taxonomically widespread plastic responses to global change drivers in many functional traits, though there is a lack of empirical support for many theoretical models on the evolution of phenotypic plasticity. Future studies should assess the adaptive value and evolutionary potential of plasticity under complex, realistic global change scenarios. Promising tools include resurrection protocols and artificial selection experiments. © 2010 New York Academy of Sciences.

Nonlinear evolutions of an ultra-intense ultra-short laser pulse in a rarefied plasma through a new quasi-static theory

Science.gov (United States)

Yazdanpanah, J.

2018-02-01

In this paper, we present a new description of self-consistent wake excitation by an intense short laser pulse, based on applying the quasi-static approximation (slow variations of the pulse-envelope) in the instantaneous Lorentz-boosted pulse co-moving frame (PCMF), and best verify our results through comparison with particle-in-cell simulations. According to this theory, the plasma motion can be treated perturbatively in the PCMF due to its high initial-velocity and produces a quasi-static wakefield in this frame. The pulse envelope, on the other hand, is governed by a form of the Schrödinger equation in the PCMF, in which the wakefield acts as an effective potential. In this context, pulse evolutions are characterized by local conservation laws resulted from this equation and subjected to Lorentz transformation into the laboratory frame. Using these conservation laws, precise formulas are obtained for spatiotemporal pulse evolutions and related wakefield variations at initial stages, and new equations are derived for instantaneous group velocity and carrier frequency. In addition, based on properties of the Schrödinger equation, spectral-evolutions of the pulse are described and the emergence of an anomalous dispersion branch with linear relation ω ≈ ck (c is the light speed) is predicted. Our results are carefully discussed versus previous publications and the significance of our approach is described by showing almost all suggestive definitions of group-velocity based on energy arguments fail to reproduce our formula and correctly describe the instantaneous pulse-velocity.

Butterfly vertebra. A case report and a short review of the literature.

Science.gov (United States)

Kapetanakis, S; Giovannopoulou, E; Nastoulis, E; Demetriou, T

2016-01-01

A butterfly vertebra is a rare congenital anomaly, encountered as isolated finding or as part of syndromic diseases. We report a case of a 40-year- old female presenting with low back pain and sciatica due to 'butterfly' dysplasia of the first sacral vertebra. This novel case includes posterolateral displacement of the completely separated hemivertebrae, causing left lateral recess stenosis and compression of S1 nerve root. Additionally, we conducted a short review of the literature. Few cases are reported in literature. Only one refers to a sacral vertebra. There is no previous case of a butterfly vertebra that accounts for narrowing of the lateral recess and associated radiculopathy.

Using mobile phones and short message service to deliver self-management interventions for chronic conditions: a meta-review.

Science.gov (United States)

Jones, Katherine R; Lekhak, Nirmala; Kaewluang, Napatsawan

2014-04-01

The worldwide burden of chronic disease is widespread and growing. This shift from acute to chronic care requires rethinking how resources are invested in managing these conditions. One response has been to create programs and interventions that have the goal of helping patients better manage their own conditions. Over time, these self-management interventions and strategies have increasingly relied on various technologies for their implementation, with the newest technology being mobile phones and short message service (SMS). The objective of this meta-review was to evaluate the current evidence on the use of mobile phones and SMS to deliver self-management interventions for chronic conditions. A meta-review was conducted of the 11 systematic reviews (SRs) that were identified and retrieved after an extensive search of electronic databases covering the years 2000-2012. Relevant information was abstracted from each systematic review and a quality assessment carried out using the AMSTAR ("A Measurement Tool to Assess Systematic Reviews") criteria. The number and types of included studies and total number of subjects varied significantly across the systematic reviews. Mobile phone text messaging was reported to significantly improve adherence to appointments and antiretroviral therapy, short-term smoking quit rates, and selected clinical and behavioral outcomes. AMSTAR scores ranged from 11 to 3, reflecting substantial variation in SR quality. Mobile phones and SMS show promise as a technology to deliver self-management interventions to improve outcomes of chronic care management. However, the quality of future studies and systematic reviews needs to be improved. There also are unresolved issues about the technology itself. © 2014 Sigma Theta Tau International.

Observations of short gamma-ray bursts.

Science.gov (United States)

Fox, Derek B; Roming, Peter W A

2007-05-15

We review recent observations of short-hard gamma-ray bursts and their afterglows. The launch and successful ongoing operations of the Swift satellite, along with several localizations from the High-Energy Transient Explorer mission, have provoked a revolution in short-burst studies: first, by quickly providing high-quality positions to observers; and second, via rapid and sustained observations from the Swift satellite itself. We make a complete accounting of Swift-era short-burst localizations and proposed host galaxies, and discuss the implications of these observations for the distances, energetics and environments of short bursts, and the nature of their progenitors. We then review the physical modelling of short-burst afterglows: while the simplest afterglow models are inadequate to explain the observations, there have been several notable successes. Finally, we address the case of an unusual burst that threatens to upset the simple picture in which long bursts are due to the deaths of massive stars, and short bursts to compact-object merger events.

A comparison of biological and cultural evolution.

Science.gov (United States)

Portin, Petter

2015-03-01

This review begins with a definition of biological evolution and a description of its general principles. This is followed by a presentation of the biological basis of culture, specifically the concept of social selection. Further, conditions for cultural evolution are proposed, including a suggestion for language being the cultural replicator corresponding to the concept of the gene in biological evolution. Principles of cultural evolution are put forward and compared to the principles of biological evolution. Special emphasis is laid on the principle of selection in cultural evolution, including presentation of the concept of cultural fitness. The importance of language as a necessary condition for cultural evolution is stressed. Subsequently, prime differences between biological and cultural evolution are presented, followed by a discussion on interaction of our genome and our culture. The review aims at contributing to the present discussion concerning the modern development of the general theory of evolution, for example by giving a tentative formulation of the necessary and sufficient conditions for cultural evolution, and proposing that human creativity and mind reading or theory of mind are motors specific for it. The paper ends with the notion of the still ongoing coevolution of genes and culture.

SWS2 visual pigment evolution as a test of historically contingent patterns of plumage color evolution in warblers.

Science.gov (United States)

Bloch, Natasha I; Morrow, James M; Chang, Belinda S W; Price, Trevor D

2015-02-01

Distantly related clades that occupy similar environments may differ due to the lasting imprint of their ancestors-historical contingency. The New World warblers (Parulidae) and Old World warblers (Phylloscopidae) are ecologically similar clades that differ strikingly in plumage coloration. We studied genetic and functional evolution of the short-wavelength-sensitive visual pigments (SWS2 and SWS1) to ask if altered color perception could contribute to the plumage color differences between clades. We show SWS2 is short-wavelength shifted in birds that occupy open environments, such as finches, compared to those in closed environments, including warblers. Phylogenetic reconstructions indicate New World warblers were derived from a finch-like form that colonized from the Old World 15-20 Ma. During this process, the SWS2 gene accumulated six substitutions in branches leading to New World warblers, inviting the hypothesis that passage through a finch-like ancestor resulted in SWS2 evolution. In fact, we show spectral tuning remained similar across warblers as well as the finch ancestor. Results reject the hypothesis of historical contingency based on opsin spectral tuning, but point to evolution of other aspects of visual pigment function. Using the approach outlined here, historical contingency becomes a generally testable theory in systems where genotype and phenotype can be connected. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

The dynamics of short envelope solitons in media with controlled dispersion

International Nuclear Information System (INIS)

Aseeva, N.V.; Gromov, E.M.; Tyutin, V.V.

2007-01-01

The dynamics of short envelope solitons in media with controlled dispersion is investigated in the framework of the third-order nonlinear Schroedinger equation. Evolution of the solitons amplitude is analyzed in the adiabatic approximation. The existence of short envelope solitons independent from linear dispersion inhomogeneity is shown

Short-Term Memory and Aphasia: From Theory to Treatment.

Science.gov (United States)

Minkina, Irene; Rosenberg, Samantha; Kalinyak-Fliszar, Michelene; Martin, Nadine

2017-02-01

This article reviews existing research on the interactions between verbal short-term memory and language processing impairments in aphasia. Theoretical models of short-term memory are reviewed, starting with a model assuming a separation between short-term memory and language, and progressing to models that view verbal short-term memory as a cognitive requirement of language processing. The review highlights a verbal short-term memory model derived from an interactive activation model of word retrieval. This model holds that verbal short-term memory encompasses the temporary activation of linguistic knowledge (e.g., semantic, lexical, and phonological features) during language production and comprehension tasks. Empirical evidence supporting this model, which views short-term memory in the context of the processes it subserves, is outlined. Studies that use a classic measure of verbal short-term memory (i.e., number of words/digits correctly recalled in immediate serial recall) as well as those that use more intricate measures (e.g., serial position effects in immediate serial recall) are discussed. Treatment research that uses verbal short-term memory tasks in an attempt to improve language processing is then summarized, with a particular focus on word retrieval. A discussion of the limitations of current research and possible future directions concludes the review. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Gradient decent based multi-objective cultural differential evolution for short-term hydrothermal optimal scheduling of economic emission with integrating wind power and photovoltaic power

International Nuclear Information System (INIS)

Zhang, Huifeng; Yue, Dong; Xie, Xiangpeng; Dou, Chunxia; Sun, Feng

2017-01-01

With the integration of wind power and photovoltaic power, optimal operation of hydrothermal power system becomes great challenge due to its non-convex, stochastic and complex-coupled constrained characteristics. This paper extends short-term hydrothermal system optimal model into short-term hydrothermal optimal scheduling of economic emission while considering integrated intermittent energy resources (SHOSEE-IIER). For properly solving SHOSEE-IIER problem, a gradient decent based multi-objective cultural differential evolution (GD-MOCDE) is proposed to improve the optimal efficiency of SHOSEE-IIER combined with three designed knowledge structures, which mainly enhances search ability of differential evolution in the shortest way. With considering those complex-coupled and stochastic constraints, a heuristic constraint-handling measurement is utilized to tackle with them both in coarse and fine tuning way, and probability constraint-handling procedures are taken to properly handle those stochastic constraints combined with their probability density functions. Ultimately, those approaches are implemented on five test systems, which testify the optimization efficiency of proposed GD-MOCDE and constraint-handling efficiency for system load balance, water balance and stochastic constraint-handling measurements, those obtained results reveal that the proposed GD-MOCDE can properly solve the SHOSEE-IIER problem combined with those constraint-handling approaches. - Highlights: • Gradient decent method is proposed to improve mutation operator. • Hydrothermal system is extended to hybrid energy system. • The uncertainty constraint is converted into deterministic constraint. • The results show the viability and efficiency of proposed algorithm.

Methylome evolution in plants.

Science.gov (United States)

Vidalis, Amaryllis; Živković, Daniel; Wardenaar, René; Roquis, David; Tellier, Aurélien; Johannes, Frank

2016-12-20

Despite major progress in dissecting the molecular pathways that control DNA methylation patterns in plants, little is known about the mechanisms that shape plant methylomes over evolutionary time. Drawing on recent intra- and interspecific epigenomic studies, we show that methylome evolution over long timescales is largely a byproduct of genomic changes. By contrast, methylome evolution over short timescales appears to be driven mainly by spontaneous epimutational events. We argue that novel methods based on analyses of the methylation site frequency spectrum (mSFS) of natural populations can provide deeper insights into the evolutionary forces that act at each timescale.

Quantitative and qualitative temporal evolution of gadolinium enhancement of spinal lesion

International Nuclear Information System (INIS)

Sze, G.; Krol, G.

1988-01-01

Seventy gadolinium-enhanced studies of spinal lesions were reviewed, and 34 were selected for analysis of the temporal quantitative and qualitative aspects of enhancement. Thirteen patients had intradural extramedullary lesions, eight had intramedullary lesions, and 13 had extradural lesions. Data analysis was conducted by measuring intensities of normal and pathologic tissues on short repetition-time (TR) scans. The evolution of enhancement of spinal tumors was found to differ, depending on which compartment the tumor was located. Intradural extramedullary nodules showed their most prominent enhancement on immediate postcontrast scans. Extradural lesions varied in behavior. Some demonstrated an increase in enhancement, while others showed a decrease. Intramedullary tumors usually showed an increase in enhancement on delayed scans. In most cases, however, the quantitative increase was minor. The exception occurred in a case of necrotic cord glioma. Immediate postcontrast short-TR scans will nearly always be sufficient for the evaluation of suspected spinal lesions. Only the very occasional case may benefit from delayed scans

Diversity, evolution, and therapeutic applications of small RNAs in prokaryotic and eukaryotic immune systems

Science.gov (United States)

Cooper, Edwin L.; Overstreet, Nicola

2014-03-01

Recent evidence supports that prokaryotes exhibit adaptive immunity in the form of CRISPR (Clustered Regularly Interspersed Short Palindromic Repeats) and Cas (CRISPR associated proteins). The CRISPR-Cas system confers resistance to exogenous genetic elements such as phages and plasmids by allowing for the recognition and silencing of these genetic elements. Moreover, CRISPR-Cas serves as a memory of past exposures. This suggests that the evolution of the immune system has counterparts among the prokaryotes, not exclusively among eukaryotes. Mathematical models have been proposed which simulate the evolutionary patterns of CRISPR, however large gaps in our understanding of CRISPR-Cas function and evolution still exist. The CRISPR-Cas system is analogous to small RNAs involved in resistance mechanisms throughout the tree of life, and a deeper understanding of the evolution of small RNA pathways is necessary before the relationship between these convergent systems is to be determined. Presented in this review are novel RNAi therapies based on CRISPR-Cas analogs and the potential for future therapies based on CRISPR-Cas system components.

Short time propagation of a singular wave function: Some surprising results

Science.gov (United States)

Marchewka, A.; Granot, E.; Schuss, Z.

2007-08-01

The Schrödinger evolution of an initially singular wave function was investigated. First it was shown that a wide range of physical problems can be described by initially singular wave function. Then it was demonstrated that outside the support of the initial wave function the time evolution is governed to leading order by the values of the wave function and its derivatives at the singular points. Short-time universality appears where it depends only on a single parameter—the value at the singular point (not even on its derivatives). It was also demonstrated that the short-time evolution in the presence of an absorptive potential is different than in the presence of a nonabsorptive one. Therefore, this dynamics can be harnessed to the determination whether a potential is absorptive or not simply by measuring only the transmitted particles density.

Short-term evolution and coexistence of spots, plages and flare activity on LQ Hydrae

Science.gov (United States)

Flores Soriano, M.; Strassmeier, K. G.

2017-01-01

Aims: We aim to study the short-term evolution of the chromospheric and photospheric activity of the young, single K2 dwarf LQ Hya. Methods: Four months of quasi-simultaneous spectroscopic and photometric observations were used to study the variations of the photometric light curve, the evolution of the chromospheric activity from the Hα and Hβ lines, and the distribution of cool spots from Doppler maps. Results: During our observations one side of the star was more active than the other. The equivalent width of the Hα line from the least active hemisphere increased from ≈0.7 Å at the beginning of the observation to 1.0 Å at the end. The basal emission of the most active hemisphere remained roughly constant at EWHαt1.0 Å. Intense flare activity was observed during the first twenty days, where at least four different events were detected. The line asymmetries of the Hα line suggest that one of the flares could have produced a mass ejection with a maximum projected speed of 70kms-1. The rotational modulation of the V-band photometry showed clear anti-correlation with the chromospheric activity. The difference in brightness between the opposite hemispheres decreased from 0.m16 to 0.m09 in two months. Three spots gradually moving apart from each other are dominating the photospheric Doppler maps. The comparison between the maps and the Hα line as the star rotates reveals the spatial coexistence of chromospheric Hα emission and photospheric spots. Conclusions: Our results indicate that the active regions of LQ Hya can live for at least four months. The detected changes in the photometric light curve and the spectroscopic Doppler images seem to be more a consequence of the spatial redistribution of the active regions rather than due to changes in their strength. Only one of the active regions shows significant changes in its chromospheric emission. Based on data obtained with the STELLA robotic telescope in Tenerife, an AIP facility jointly operated by AIP

Evolution of Principle and Practice of Electrodeposited Thin Film: A Review on Effect of Temperature and Sonication

Directory of Open Access Journals (Sweden)

A. Mallik

2011-01-01

Full Text Available This review discusses briefly the important aspects of thin films. The introduction of the article is a summary of evolution of thin films from surface engineering, their deposition methods, and important issues. The fundamental aspects of electrochemical deposition with special emphasis on the effect of temperature on the phase formation have been reviewed briefly. The field of sonoelectrochemistry has been discussed in the paper. The literature regarding the effects of temperature and sonication on the structure and morphology of the deposits and nucleation mechanisms, residual stress, and mechanical properties has also been covered briefly.

The evolution of Lean organizations

OpenAIRE

Serafinas, Dalius; Ruželė, Darius

2014-01-01

Remiantis evoliucijos tyrimų modeliais bei autorių sudarytu evoliucionuojančios organizacijos modeliu,straipsnyje analizuojama Lean vadybos metodologija ir tiriama, kaip evoliucionuoja ją įgyvendinančios Lietuvosgamybinės organizacijos. The purpose of this paper is to examine the evolution of Lean organizations.Design/methodology/approach: a conceptual literature on the evolution of species, organisms and organizations was reviewed and an original model (framework) of the evolution of orga...

Cepheid evolution

International Nuclear Information System (INIS)

Becker, S.A.

1984-05-01

A review of the phases of stellar evolution relevant to Cepheid variables of both Types I and II is presented. Type I Cepheids arise as a result of normal post-main sequence evolutionary behavior of many stars in the intermediate to massive range of stellar masses. In contrast, Type II Cepheids generally originate from low-mass stars of low metalicity which are undergoing post core helium-burning evolution. Despite great progress in the past two decades, uncertainties still remain in such areas as how to best model convective overshoot, semiconvection, stellar atmospheres, rotation, and binary evolution as well as uncertainties in important physical parameters such as the nuclear reaction rates, opacity, and mass loss rates. The potential effect of these uncertainties on stellar evolution models is discussed. Finally, comparisons between theoretical predictions and observations of Cepheid variables are presented for a number of cases. The results of these comparisons show both areas of agreement and disagreement with the latter result providing incentive for further research

Extinction Events Can Accelerate Evolution

DEFF Research Database (Denmark)

Lehman, Joel; Miikkulainen, Risto

2015-01-01

Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate...... evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending...... computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific...

Mosaic evolution of the mammalian auditory periphery.

Science.gov (United States)

Manley, Geoffrey A

2013-01-01

The classical mammalian auditory periphery, i.e., the type of middle ear and coiled cochlea seen in modern therian mammals, did not arise as one unit and did not arise in all mammals. It is also not the only kind of auditory periphery seen in modern mammals. This short review discusses the fact that the constituents of modern mammalian auditory peripheries arose at different times over an extremely long period of evolution (230 million years; Ma). It also attempts to answer questions as to the selective pressures that led to three-ossicle middle ears and the coiled cochlea. Mammalian middle ears arose de novo, without an intermediate, single-ossicle stage. This event was the result of changes in eating habits of ancestral animals, habits that were unrelated to hearing. The coiled cochlea arose only after 60 Ma of mammalian evolution, driven at least partly by a change in cochlear bone structure that improved impedance matching with the middle ear of that time. This change only occurred in the ancestors of therian mammals and not in other mammalian lineages. There is no single constellation of structural features of the auditory periphery that characterizes all mammals and not even all modern mammals.

Modern treatment of short bowel syndrome

DEFF Research Database (Denmark)

Jeppesen, Palle B

2013-01-01

Recently, the US Food and Drug Administration and the European Medicines Agency approved the glucagon-like peptide 2 analogue, teduglutide, for the treatment of short bowel syndrome (SBS), and this review describes the physiological basis for its clinical use.......Recently, the US Food and Drug Administration and the European Medicines Agency approved the glucagon-like peptide 2 analogue, teduglutide, for the treatment of short bowel syndrome (SBS), and this review describes the physiological basis for its clinical use....

Imaging in short stature.

Science.gov (United States)

Chaudhary, Vikas; Bano, Shahina

2012-09-01

Short stature can be a sign of disease, disability, and social stigma causing psychological stress. It is important to have an early diagnosis and treatment. Short stature may result from skeletal dysplasias, endocrine disorders, may be familial, or may be the result of malnutrition and chronic illnesses. A team effort of the healthcare professionals like pediatricians, endocrinologists, radiologists, and pathologists is required to diagnose, treat and monitor various pathological conditions associated with growth abnormality. In this review, we have discussed the role of imaging in diagnosing and characterizing various pathological conditions associated with short stature.

The role of epidemiology in determining if a simple short fall can cause fatal head injury in an infant: a subject review and reflection.

Science.gov (United States)

Ehsani, Johnathon P; Ibrahim, Joseph E; Bugeja, Lyndal; Cordner, Stephen

2010-09-01

This article is a subject review summarizing and interpreting the existing knowledge on the question "Can a simple short fall cause fatal head injury in an infant?" It also reflects on the challenges of undertaking a review in the contentious area of pediatric forensic pathology. The authors identified and considered 1055 publications for inclusion. Using explicit selection criteria 27 publications were included in the subject review. The literature suggests that it is rare, but possible, for fatal head injury to occur from a simple short fall. Large population studies of childhood injuries indicate that severe head injury from a short fall is extremely rare. This is counter pointed by a single documented case report that demonstrates it can happen. The question of whether it is a credible claim in a particular case is inextricable from the circumstances of that case.To strengthen the evidence based on fatal potential of simple short falls in infants, future studies addressing this question would ideally be prospective in design and include the key elements of: (1) a large sample size, (2) clearly defined comparison groups, (3) clear and verifiable criteria for causation, (4) specified fall height, (5) specified fall type: vertical free fall or the presence of additional forces, (6) composition of contact surface, and (7) nature of contact point: concentrated to one point or onto a flat surface.We believe subject reviews for forensic pathology require a specific approach because the application of information differs between clinical and courtroom settings.

Diversification, evolution and methylation of short interspersed nuclear element families in sugar beet and related Amaranthaceae species.

Science.gov (United States)

Schwichtenberg, Katrin; Wenke, Torsten; Zakrzewski, Falk; Seibt, Kathrin M; Minoche, André; Dohm, Juliane C; Weisshaar, Bernd; Himmelbauer, Heinz; Schmidt, Thomas

2016-01-01

Short interspersed nuclear elements (SINEs) are non-autonomous non-long terminal repeat retrotransposons which are widely distributed in eukaryotic organisms. While SINEs have been intensively studied in animals, only limited information is available about plant SINEs. We analysed 22 SINE families from seven genomes of the Amaranthaceae family and identified 34 806 SINEs, including 19 549 full-length copies. With the focus on sugar beet (Beta vulgaris), we performed a comparative analysis of the diversity, genomic and chromosomal organization and the methylation of SINEs to provide a detailed insight into the evolution and age of Amaranthaceae SINEs. The lengths of consensus sequences of SINEs range from 113 nucleotides (nt) up to 224 nt. The SINEs show dispersed distribution on all chromosomes but were found with higher incidence in subterminal euchromatic chromosome regions. The methylation of SINEs is increased compared with their flanking regions, and the strongest effect is visible for cytosines in the CHH context, indicating an involvement of asymmetric methylation in the silencing of SINEs. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Chemical evolution and life

Directory of Open Access Journals (Sweden)

Malaterre Christophe

2015-01-01

Full Text Available In research on the origins of life, the concept of “chemical evolution” aims at explaining the transition from non-living matter to living matter. There is however strong disagreement when it comes to defining this concept more precisely, and in particular with reference to a chemical form of Darwinian evolution: for some, chemical evolution is nothing but Darwinian evolution applied to chemical systems before life appeared; yet, for others, it is the type of evolution that happened before natural selection took place, the latter being the birthmark of living systems. In this contribution, I review the arguments defended by each side and show how both views presuppose a dichotomous definition of “life”.

Mandibular dental arch short and long-term spontaneous dentoalveolar changes after slow or rapid maxillary expansion: a systematic review

Directory of Open Access Journals (Sweden)

Arthur César de Medeiros Alves

Full Text Available ABSTRACT Objective: The aim of this systematic review was to analyze the short and long-term spontaneous dentoalveolar changes of the mandibular dental arch after slow (SME or rapid (RME maxillary expansion in the mixed and early permanent dentitions. Methods: An electronic search was performed in the following databases: PubMed/Medline, Cochrane Library, Scopus, Embase and Web of Science. Eligibility criteria for article selection included randomized controlled trials and prospective studies written in English, with no restriction of year of publication, involving patients who underwent SME or RME during the mixed or early permanent dentitions. A double-blind search of articles was performed by two reviewers. Initially, the title and the abstract of the studies were read, and their references were also hand-searched for possible missing studies. A methodological quality scoring scale was used to analyze the selected articles. Results: The search retrieved 373 articles, but only 6 were selected for review after application of the eligibility and exclusion criteria. Non-clinically significant spontaneous dentoalveolar changes of approximately 1mm were found in the mandibular dental arch in the short and long-term, after slow or rapid maxillary expansions. Furthermore, no significant differences were found between treated and control groups. Conclusions: There is enough evidence to conclude that negligible short and long-term spontaneous dentoalveolar changes tend to occur in the mandibular dental arch after SME or RME in the mixed and early permanent dentitions. More randomized studies with appropriate control group are required to better evaluate this issue.

A Platform for Simulating Language Evolution

Science.gov (United States)

Vogel, Carl; Woods, Justin

A platform for conducting experiments in the simulation of natural language evolution is presented. The system is paramaterized for independent specification of important features like: number of agents, communication attempt frequency, agent short term memory capacity, communicative urgency, etc. Representative experiments are demonstrated.

Dihadron fragmentation function and its evolution

International Nuclear Information System (INIS)

Majumder, A.; Wang Xinnian

2004-01-01

Dihadron fragmentation functions and their evolution are studied in the process of e + e - annihilation. Under the collinear factorization approximation and facilitated by the cut-vertex technique, the two hadron inclusive cross section at leading order is shown to factorize into a short distance parton cross section and a long distance dihadron fragmentation function. We provide the definition of such a dihadron fragmentation function in terms of parton matrix elements and derive its Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation at leading log. The evolution equation for the nonsinglet quark fragmentation function is solved numerically with a simple ansatz for the initial condition and results are presented for cases of physical interest

Short wavelength FELS

International Nuclear Information System (INIS)

Sheffield, R.L.

1991-01-01

The generation of coherent ultraviolet and shorter wavelength light is presently limited to synchrotron sources. The recent progress in the development of brighter electron beams enables the use of much lower energy electron rf linacs to reach short-wavelengths than previously considered possible. This paper will summarize the present results obtained with synchrotron sources, review proposed short- wavelength FEL designs and then present a new design which is capable of over an order of magnitude higher power to the extreme ultraviolet. 17 refs., 10 figs

Short wavelength FELS

Energy Technology Data Exchange (ETDEWEB)

Sheffield, R.L.

1991-01-01

The generation of coherent ultraviolet and shorter wavelength light is presently limited to synchrotron sources. The recent progress in the development of brighter electron beams enables the use of much lower energy electron rf linacs to reach short-wavelengths than previously considered possible. This paper will summarize the present results obtained with synchrotron sources, review proposed short- wavelength FEL designs and then present a new design which is capable of over an order of magnitude higher power to the extreme ultraviolet. 17 refs., 10 figs.

Imaging in short stature

Directory of Open Access Journals (Sweden)

Vikas Chaudhary

2012-01-01

Full Text Available Short stature can be a sign of disease, disability, and social stigma causing psychological stress. It is important to have an early diagnosis and treatment. Short stature may result from skeletal dysplasias, endocrine disorders, may be familial, or may be the result of malnutrition and chronic illnesses. A team effort of the healthcare professionals like pediatricians, endocrinologists, radiologists, and pathologists is required to diagnose, treat and monitor various pathological conditions associated with growth abnormality. In this review, we have discussed the role of imaging in diagnosing and characterizing various pathological conditions associated with short stature.

A Short review on wrought austenitic stainless steels at high temperatures: processing, microstructure, properties and performance

Directory of Open Access Journals (Sweden)

Ronald Lesley Plaut

2007-12-01

Full Text Available Wrought austenitic stainless steels are widely used in high temperature applications. This short review discusses initially the processing of this class of steels, with emphasis on solidification and hot working behavior. Following, a brief summary is made on the precipitation behavior and the numerous phases that may appear in their microstructures. Creep and oxidation resistance are, then, briefly discussed, and finalizing their performance is compared with other high temperature metallic materials.

The 2014-15 eruption and the short-term geochemical evolution of the Fogo volcano (Cape Verde): Evidence for small-scale mantle heterogeneity

Science.gov (United States)

Mata, J.; Martins, S.; Mattielli, N.; Madeira, J.; Faria, B.; Ramalho, R. S.; Silva, P.; Moreira, M.; Caldeira, R.; Moreira, M.; Rodrigues, J.; Martins, L.

2017-09-01

Recurrent eruptions at very active ocean island volcanoes provide the ideal means to gain insight on the scale of spatial variations at the mantle source and on temporal changes of magma genesis and evolution processes. In 2014, after 19 years of quiescence, Fogo volcano (Cape Verde Archipelago) experienced a new eruption, with the vents located 200 m from those of the 1995 eruption, and less than 2000 m from those of the 1951 event. This offered a unique opportunity to investigate the existence of small-scale mantle heterogeneities and the short-term compositional evolution of magmas erupted by a very active oceanic volcano like Fogo. Here we present petrological and geochemical data from the early stages of the Fogo's most recent eruption - started on November 23, 2014 - and compare them with the signature of previous eruptions (particularly those of 1995 and 1951). The magmas erupted in 2014 are alkaline (up to 23.4% and 0.94% of normative ne and lc, respectively) with somewhat evolved compositions (Mg # < 56), ranging from tephrites to phonotephrites. The eruption of phonotephritic lavas preceded the effusion of tephritic ones. Lavas carried to the surface clinopyroxene and kaersutite phenocrysts and cognate megacrysts, which indicate that the main stages of magma evolution occurred in magma chambers most probably located at mantle depths (25.6 ± 5.5 km below sea level). This was followed by a shallower (< 1.5 km below sea level) and shorter (≈ 50 days) magma stagnation before the eruption. 2014 magmas have more unradiogenic Sr and more radiogenic Nd compositions than those of the previous 1951 and 1995 eruptions, which generally have less radiogenic Pb ratios. These isotopic differences - coming from quasi-coeval materials erupted almost in the same place - are remarkable and reflect the small-scale heterogeneity of the underlying mantle source. Moreover, they reflect the limited isotopic averaging of the source composition during partial melting events as

[Materials/Biomaterials in Clinical Practice - a Short Review and Current Trends].

Science.gov (United States)

Bolle, T; Meyer, F; Walcher, F; Lohmann, C; Jockenhövel, S; Gries, T; Hoffmann, W

2017-04-01

Biomaterials play a major role in interventional medicine and surgery. However, the development of biomaterials is still in its early phases in spite of the huge progress made within the last decades. On the one hand, this is because our knowledge of the molecular and cellular processes associated with biomaterials is still increasing exponentially. On the other hand, a wide variety of advanced materials with highly interesting properties is being developed currently. This review provides a short introduction into the variety of materials in use as well as their application in interventional medicine and surgery. Also the importance of biomaterials for tissue engineering in the field of regenerative medicine and the functionalisation of biomaterials, including sterilisation methods are discussed. For the future, an even broader interdisciplinary scientific collaboration is necessary in order to develop novel biomaterials and facilitate their translation into clinical practice. Georg Thieme Verlag KG Stuttgart · New York.

Chemical evolution of galaxies

International Nuclear Information System (INIS)

Matteucci, F.; Consiglio Nazionale delle Ricerche, Frascati

1989-01-01

In principle, a good model of galactic chemical evolution should fulfil the majority of well established observational constraints. The goal of this paper is to review the observational data together with the existing chemical evolution models for the Milky Way (the disk), Blue Compact and Elliptical galaxies and to show how well the models can account for the observations. Some open problems and future prospects are also discussed. (author)

Intrinsic and extrinsic carbohydrates in the vagina: A short review on vaginal glycogen.

Science.gov (United States)

Tester, Richard; Al-Ghazzewi, Farage H

2018-06-01

The reasons for (i) the presence and (ii) mechanisms of utilisation of glycogen by the lactic acid bacteria in the human vaginal tract are not well understood. It is probable that the vaginal epithelia produce both glycogen and α-amylase where the enzyme depolymerises the polysaccharide within the vagina itself. Only these depolymerised residues are then utilised for growth by the lactic acid bacteria. The lactic acid bacteria cannot metabolise the glycogen directly due to their incapacity to produce the α-amylase enzyme. These bacteria may, however, metabolise exogenous carbohydrates (such as prebiotics) selectively for growth effectively. These carbohydrate utilisation issues within the vagina are considered in this short review. Copyright © 2018 Elsevier B.V. All rights reserved.

Evolution and merging of binaries with compact objects

International Nuclear Information System (INIS)

Bethe, Hans A.; Brown, Gerald E.; Lee, Chang-Hwan

2007-01-01

In the light of recent observations in which short γ-ray bursts are interpreted as arising from black-hole(BH), neutron-star(NS) or NS-NS mergings we would like to review our research on the evolution of compact binaries, especially those containing NS's. These were carried out with predictions for LIGO in mind, but are directly applicable to short γ-ray bursts in the interpretation above. Most important in our review is that we show that the standard scenario for evolving NS-NS binaries always ends up with a low-mass BH (LMBH), NS binary. Bethe and Brown [1998, Astrophys. J. 506, 780] showed that this fate could be avoided if the two giants in the progenitor binary burned He at the same time, and that in this way the binary could avoid the common envelope evolution of the NS with red giant companion which sends the first born NS into a BH in the standard scenario. The burning of He at the same time requires, for the more massive giants such as the progenitors of the Hulse-Taylor binary NS that the two giants be within 4% of each other in zero age main sequence (ZAMS) mass. Applying this criterion to all binaries results in a factor ∼5 of LMBH-NS binaries as compared with NS-NS binaries. Although this factor is substantially less than the originally claimed factor of 20 which Bethe and Brown (1998) estimated, largely because a careful evolution has been carried through here, our factor 5 is augmented by a factor of ∼8 arising from the higher rate of star formation in the earlier Galaxy from which the BH-NS binaries came from. Furthermore, here we calculate the mergers for short-hard gamma-ray bursts, whereas Bethe and Brown's factor 20 included a factor of 2 for the higher chirp masses in a BH-NS binary as compared with NS-NS one. In short, we end up with an estimate of factor ∼40 over that calculated with NS-NS binary mergers in our Galaxy alone. Our total rate is estimated to be about one merging of compact objects per year. Our scenario of NS-NS binaries

The chemical evolution of galaxies

International Nuclear Information System (INIS)

Chiosi, Cesare

1986-01-01

The chemical evolution of galaxies is reviewed with particular attention to the theoretical interpretation of the distribution and abundances of elements in stars and the interstellar medium. The paper was presented to the conference on ''The early universe and its evolution'', Erice, Italy, 1986. The metallicity distribution of the solar vicinity, age metallicity relationship, abundance gradients in the galaxy, external galaxies, star formation and evolution, major sites of nucleosynthesis, yields of chemical elements, chemical models, and the galactic disk, are all discussed. (U.K.)

Evolution across the Curriculum: Microbiology

Directory of Open Access Journals (Sweden)

Alita R. Burmeister

2016-05-01

Full Text Available An integrated understanding of microbiology and evolutionary biology is essential for students pursuing careers in microbiology and healthcare fields. In this Perspective, we discuss the usefulness of evolutionary concepts and an overall evolutionary framework for students enrolled in microbiology courses. Further, we propose a set of learning goals for students studying microbial evolution concepts. We then describe some barriers to microbial evolution teaching and learning and encourage the continued incorporation of evidence-based teaching practices into microbiology courses at all levels. Next, we review the current status of microbial evolution assessment tools and describe some education resources available for teaching microbial evolution. Successful microbial evolution education will require that evolution be taught across the undergraduate biology curriculum, with a continued focus on applications and applied careers, while aligning with national biology education reform initiatives.

Evolution across the Curriculum: Microbiology

Science.gov (United States)

Burmeister, Alita R.; Smith, James J.

2016-01-01

An integrated understanding of microbiology and evolutionary biology is essential for students pursuing careers in microbiology and healthcare fields. In this Perspective, we discuss the usefulness of evolutionary concepts and an overall evolutionary framework for students enrolled in microbiology courses. Further, we propose a set of learning goals for students studying microbial evolution concepts. We then describe some barriers to microbial evolution teaching and learning and encourage the continued incorporation of evidence-based teaching practices into microbiology courses at all levels. Next, we review the current status of microbial evolution assessment tools and describe some education resources available for teaching microbial evolution. Successful microbial evolution education will require that evolution be taught across the undergraduate biology curriculum, with a continued focus on applications and applied careers, while aligning with national biology education reform initiatives. Journal of Microbiology & Biology Education PMID:27158306

Molecular evolution and diversification of snake toxin genes, revealed by analysis of intron sequences.

Science.gov (United States)

Fujimi, T J; Nakajyo, T; Nishimura, E; Ogura, E; Tsuchiya, T; Tamiya, T

2003-08-14

The genes encoding erabutoxin (short chain neurotoxin) isoforms (Ea, Eb, and Ec), LsIII (long chain neurotoxin) and a novel long chain neurotoxin pseudogene were cloned from a Laticauda semifasciata genomic library. Short and long chain neurotoxin genes were also cloned from the genome of Laticauda laticaudata, a closely related species of L. semifasciata, by PCR. A putative matrix attached region (MAR) sequence was found in the intron I of the LsIII gene. Comparative analysis of 11 structurally relevant snake toxin genes (three-finger-structure toxins) revealed the molecular evolution of these toxins. Three-finger-structure toxin genes diverged from a common ancestor through two types of evolutionary pathways (long and short types), early in the course of evolution. At a later stage of evolution in each gene, the accumulation of mutations in the exons, especially exon II, by accelerated evolution may have caused the increased diversification in their functions. It was also revealed that the putative MAR sequence found in the LsIII gene was integrated into the gene after the species-level divergence.

The Short Circuit Model of Reading.

Science.gov (United States)

Lueers, Nancy M.

The name "short circuit" has been given to this model because, in many ways, it adequately describes what happens bioelectrically in the brain. The "short-circuiting" factors include linguistic, sociocultural, attitudinal and motivational, neurological, perceptual, and cognitive factors. Research is reviewed on ways in which each one affects any…

Evolution of microbial pathogens.

OpenAIRE

Morschhäuser, J; Köhler, G; Ziebuhr, W; Blum-Oehler, G; Dobrindt, U; Hacker, J

2000-01-01

Various genetic mechanisms including point mutations, genetic rearrangements and lateral gene transfer processes contribute to the evolution of microbes. Long-term processes leading to the development of new species or subspecies are termed macroevolution, and short-term developments, which occur during days or weeks, are considered as microevolution. Both processes, macro- and microevolution need horizontal gene transfer, which is particularly important for the development of pathogenic micr...

Evolution and developmental genetics of floral display-A review of progress

Institute of Scientific and Technical Information of China (English)

Qing Ma; Wenheng Zhang; Qiu-Yun (Jenny) Xiang

2017-01-01

Angiosperms evolved a great diversity of ways to display their flowers for reproductive success by variation in floral color,size,shape,scent,arrangements,and flowering time.The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences can drive new ecological adaptations,speciation,and angiosperm diversification.Evolutionary developmental biology (evo-devo) seeks to uncover the developmental and genetic basis underlying morphological diversification.Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution.A number of regulatory genes controlling floral and inflorescence development have been identified in model plants (e.g.,Arabidopsis thaliana,Antirrhinum majus) using forward genetics and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics.Gene-regulatory networks that mediated the developmental progresses of floral and inflorescence development have also been established in some plant species.Meanwhile,phylogeny-based comparative analysis of morphological and genetic character has enabled the identification of key evolutionary events that lead to morphological complexity and diversification.Here we review the recent progress on evo-devo studies of floral display including floral symmetry,petal fusion,floral color,floral scent,and inflorescences.We also review the molecular genetic approaches applied to plant evo-devo studies and highlight the future directions of evo-devo.

Behavioural Models of Motor Control and Short-Term Memory

OpenAIRE

Imanaka, Kuniyasu; Funase, Kozo; Yamauchi, Masaki

1995-01-01

We examined in this review article the behavioural and conceptual models of motor control and short-term memory which have intensively been investigated since the 1970s. First, we reviewed both the dual-storage model of short-term memory in which movement information is stored and a typical model of motor control which emphasizes the importance of efferent factors. We then examined two models of preselection effects: a cognitive model and a cognitive/ efferent model. Following this we reviewe...

Using Recent BCI Literature to Deepen our Understanding of Clinical Neurofeedback: A Short Review.

Science.gov (United States)

Jeunet, Camille; Lotte, Fabien; Batail, Jean-Marie; Philip, Pierre; Micoulaud Franchi, Jean-Arthur

2018-05-15

In their recent paper, Alkoby et al. (2017) provide the readership with an extensive and very insightful review of the factors influencing NeuroFeedback (NF) performance. These factors are drawn from both the NF literature and the Brain-Computer Interface (BCI) literature. Our short review aims to complement Alkoby et al.'s review by reporting recent additions to the BCI literature. The object of this paper is to highlight this literature and discuss its potential relevance and usefulness to better understand the processes underlying NF and further improve the design of clinical trials assessing NF efficacy. Indeed, we are convinced that while NF and BCI are fundamentally different in many ways, both the BCI and NF communities could reach compelling achievements by building upon one another. By reviewing the recent BCI literature, we identified three types of factors that influence BCI performance: task-specific, cognitive/motivational and technology-acceptance-related factors. Since BCIs and NF share a common goal (i.e., learning to modulate specific neurophysiological patterns), similar cognitive and neurophysiological processes are likely to be involved during the training process. Thus, the literature on BCI training may help (1) to deepen our understanding of neurofeedback training processes and (2) to understand the variables that influence the clinical efficacy of NF. This may help to properly assess and/or control the influence of these variables during randomized controlled trials. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Numerical simulation of lowest-order short-crested wave instabilities

DEFF Research Database (Denmark)

Fuhrman, David R.; Madsen, Per A.; Bingham, Harry

2006-01-01

instabilities. These correctly lead to well-known (nearly symmetric) recurrence cycles below a previously established breaking threshold steepness, and to an asymmetric evolution (characterized by a permanent transfer of energy to the lower side-band) above this threshold, with dissipation from a smoothing...... that the unstable evolution of these initially three-dimensional waves leads to an asymmetric evolution, even for weakly nonlinear cases presumably well below breaking. This is characterized by an energy transfer to the lower side-band, which is also accompanied by a similar transfer to more distant upper side......-bands. At larger steepness, the evolution leads to a permanent downshift of both the mean and peak frequencies, driven in part by dissipation, effectively breaking the quasi-recurrence cycle. A single case involving a class Ib short-crested wave instability at relatively large steepness is also considered, which...

Evolution of massive stars

International Nuclear Information System (INIS)

Loore, C. de

1984-01-01

The evolution of stars with masses larger than 15 sun masses is reviewed. These stars have large convective cores and lose a substantial fraction of their matter by stellar wind. The treatment of convection and the parameterisation of the stellar wind mass loss are analysed within the context of existing disagreements between theory and observation. The evolution of massive close binaries and the origin of Wolf-Rayet Stars and X-ray binaries is also sketched. (author)

Short Rotations in Forest Plantations Accelerate Virulence Evolution in Root-Rot Pathogenic Fungi

Directory of Open Access Journals (Sweden)

Jean-Paul Soularue

2017-06-01

Full Text Available As disease outbreaks in forest plantations are causing concern worldwide, a clear understanding of the influence of silvicultural practices on the development of epidemics is still lacking. Importantly, silvicultural practices are likely to simultaneously affect epidemiological and evolutionary dynamics of pathogen populations. We propose a genetically explicit and individual-based model of virulence evolution in a root-rot pathogenic fungus spreading across forest landscapes, taking the Armillaria ostoyae–Pinus pinaster pathosystem as reference. We used the model to study the effects of rotation length on the evolution of virulence and the propagation of the fungus within a forest landscape composed of even-aged stands regularly altered by clear-cutting and thinning operations. The life cycle of the fungus modeled combines asexual and sexual reproduction modes, and also includes parasitic and saprotrophic phases. Moreover, the tree susceptibility to the pathogen is primarily determined by the age of the stand. Our simulations indicated that the shortest rotation length accelerated both the evolution of virulence and the development of the epidemics, whatever the genetic variability in the initial fungal population and the asexuality rate of the fungal species

A review of the evolution of human reliability analysis methods at nuclear industry

International Nuclear Information System (INIS)

Oliveira, Lécio N. de; Santos, Isaac José A. Luquetti dos; Carvalho, Paulo V.R.

2017-01-01

This paper reviews the status of researches on the application of human reliability analysis methods at nuclear industry and its evolution along the years. Human reliability analysis (HRA) is one of the elements used in Probabilistic Safety Analysis (PSA) and is performed as part of PSAs to quantify the likelihood that people will fail to take action, such as errors of omission and errors of commission. Although HRA may be used at lots of areas, the focus of this paper is to review the applicability of HRA methods along the years at nuclear industry, especially in Nuclear Power Plants (NPP). An electronic search on CAPES Portal of Journals (A bibliographic database) was performed. This literature review covers original papers published since the first generation of HRA methods until the ones published on March 2017. A total of 94 papers were retrieved by the initial search and 13 were selected to be fully reviewed and for data extraction after the application of inclusion and exclusion criteria, quality and suitability evaluation according to applicability at nuclear industry. Results point out that the methods from first generation are more used in practice than methods from second generation. This occurs because it is more concentrated towards quantification, in terms of success or failure of human action what make them useful for quantitative risk assessment to PSA. Although the second generation considers context and error of commission in human error prediction, they are not wider used in practice at nuclear industry to PSA. (author)

A review of the evolution of human reliability analysis methods at nuclear industry

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Lécio N. de; Santos, Isaac José A. Luquetti dos; Carvalho, Paulo V.R., E-mail: lecionoliveira@gmail.com, E-mail: luquetti@ien.gov.br, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-11-01

This paper reviews the status of researches on the application of human reliability analysis methods at nuclear industry and its evolution along the years. Human reliability analysis (HRA) is one of the elements used in Probabilistic Safety Analysis (PSA) and is performed as part of PSAs to quantify the likelihood that people will fail to take action, such as errors of omission and errors of commission. Although HRA may be used at lots of areas, the focus of this paper is to review the applicability of HRA methods along the years at nuclear industry, especially in Nuclear Power Plants (NPP). An electronic search on CAPES Portal of Journals (A bibliographic database) was performed. This literature review covers original papers published since the first generation of HRA methods until the ones published on March 2017. A total of 94 papers were retrieved by the initial search and 13 were selected to be fully reviewed and for data extraction after the application of inclusion and exclusion criteria, quality and suitability evaluation according to applicability at nuclear industry. Results point out that the methods from first generation are more used in practice than methods from second generation. This occurs because it is more concentrated towards quantification, in terms of success or failure of human action what make them useful for quantitative risk assessment to PSA. Although the second generation considers context and error of commission in human error prediction, they are not wider used in practice at nuclear industry to PSA. (author)

A short history of the CANDU nuclear power system

Energy Technology Data Exchange (ETDEWEB)

Brooks, G L

1993-04-01

This paper provides a short historical summary of the evolution of the CANDU nuclear power system with emphasis on the roles played by Ontario Hydro and private sector companies in Ontario in collaboration with Atomic Energy of Canada Limited (AECL). (author). 1 fig., 61 refs.

A short history of the CANDU nuclear power system

International Nuclear Information System (INIS)

Brooks, G.L.

1993-04-01

This paper provides a short historical summary of the evolution of the CANDU nuclear power system with emphasis on the roles played by Ontario Hydro and private sector companies in Ontario in collaboration with Atomic Energy of Canada Limited (AECL). (author). 1 fig., 61 refs

A review of short naps and sleep inertia: do naps of 30 min or less really avoid sleep inertia and slow-wave sleep?

Science.gov (United States)

Hilditch, Cassie J; Dorrian, Jillian; Banks, Siobhan

2017-04-01

Napping is a widely used countermeasure to sleepiness and impaired performance caused by sleep loss and circadian pressure. Sleep inertia, the period of grogginess and impaired performance experienced after waking, is a potential side effect of napping. Many industry publications recommend naps of 30 min or less to avoid this side effect. However, the evidence to support this advice is yet to be thoroughly reviewed. Electronic databases were searched, and defined criteria were applied to select articles for review. The review covers literature on naps of 30 min or less regarding (a) sleep inertia, (b) slow-wave sleep (SWS) and (c) the relationship between sleep inertia and SWS. The review found that although the literature on short afternoon naps is relatively comprehensive, there are very few studies on naps of 30 min or less at night. Studies have mixed results regarding the onset of SWS and the duration and severity of sleep inertia following short naps, making guidelines regarding their use unclear. The varying results are likely due to differing sleep/wake profiles before the nap of interest and the time of the day at waking. The review highlights the need to have more detailed guidelines about the implementation of short naps according to the time of the day and prior sleep/wake history. Without this context, such a recommendation is potentially misleading. Further research is required to better understand the interactions between these factors, especially at night, and to provide more specific recommendations. Copyright © 2017 Elsevier B.V. All rights reserved.

Evolution of dosimetric phantoms

International Nuclear Information System (INIS)

Reddy, A.R.

2010-01-01

In this oration evolution of the dosimetric phantoms for radiation protection and for medical use is briefly reviewed. Some details of the development of Indian Reference Phantom for internal dose estimation are also presented

Influence of traditional dance training programs on dynamic balance of people with intellectual disability: a short review

OpenAIRE

Vasileios, K.

2015-01-01

Traditional dance is gaining popularity as an intervention choice for improving poor balance ability of people with intellectual disability (ID). Balance improvement for individuals with ID through dance provides opportunities for participation in sport activities and promotes independent living. This short review provides in brief research evidence of dynamic balance improvement as measured by means of a balance deck in duration of 30, 45, and 60 sec intervals, highlighting the need to incor...

Why the short face? Developmental disintegration of the neurocranium drives convergent evolution in neotropical electric fishes.

Science.gov (United States)

Evans, Kory M; Waltz, Brandon; Tagliacollo, Victor; Chakrabarty, Prosanta; Albert, James S

2017-03-01

Convergent evolution is widely viewed as strong evidence for the influence of natural selection on the origin of phenotypic design. However, the emerging evo-devo synthesis has highlighted other processes that may bias and direct phenotypic evolution in the presence of environmental and genetic variation. Developmental biases on the production of phenotypic variation may channel the evolution of convergent forms by limiting the range of phenotypes produced during ontogeny. Here, we study the evolution and convergence of brachycephalic and dolichocephalic skull shapes among 133 species of Neotropical electric fishes (Gymnotiformes: Teleostei) and identify potential developmental biases on phenotypic evolution. We plot the ontogenetic trajectories of neurocranial phenotypes in 17 species and document developmental modularity between the face and braincase regions of the skull. We recover a significant relationship between developmental covariation and relative skull length and a significant relationship between developmental covariation and ontogenetic disparity. We demonstrate that modularity and integration bias the production of phenotypes along the brachycephalic and dolichocephalic skull axis and contribute to multiple, independent evolutionary transformations to highly brachycephalic and dolichocephalic skull morphologies.

Fuel consumption: short term and long term price impacts per population type; Consommation de carburant: effets des prix a court et a long termes par type de population

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

This report presents assessments of the price sensitivity of household fuel consumption. After a literature review on price-elasticity assessments and the use of pseudo-panels, the investigation analyses the deciding factors of the household fuel expense and its evolution between 1985 and 2006. It proposes a short term price-elasticity assessment based on the most recent survey, and also proposes price-elasticity assessments for sub-populations, notably in terms of income level or location (rural or urban areas)

Evolution of complexity in RNA-like replicator systems

Directory of Open Access Journals (Sweden)

Hogeweg Paulien

2008-03-01

significantly depend on the mutation rate. Conclusion The interdependence of information and organization can play an important role for the evolution of complexity. Namely, the emergent ecosystem supplies a context in which a novel phenotype gains functionality. Realizing such a phenotype, novel genotypes can evolve, which, in turn, results in the evolution of more complex ecological organization. Hence, the evolutionary feedback between information and organization, and thereby the evolution of complexity. Reviewers This article was reviewed by Eugene V Koonin, Eörs Szathmáry (nominated by Anthony M Poole, and Chris Adami. For the full reviews, please go to the Reviewers' comments section.

Spatial distribution, luminosity function and cosmological evolution of quasars

International Nuclear Information System (INIS)

Mathez, G.

1981-01-01

The different ways of studying quasars statistics and evolution are reviewed. Attempt is given to deduce, from the observed evolution, some constraints on physical models of energy sources in quasars [fr

Rating of Perceived Exertion for Quantification of Training and Combat Loads During Combat Sport-Specific Activities: A Short Review.

Science.gov (United States)

Slimani, Maamer; Davis, Philip; Franchini, Emerson; Moalla, Wassim

2017-10-01

The aim of this short review was to summarize data pertaining to the rating of perceived exertion (RPE) methods (RPE value and session-RPE) during combat sport-specific activities (i.e., competition and training) based on many factors, including contest type (i.e., official vs. simulated vs. training), combat rounds, age of participants and muscle groups, and their correlation with physiological variables (i.e., blood lactate concentration [La] and heart rate [HR]). The current review shows higher RPE in a match of mixed martial arts (MMAs) than Brazilian jiu-jitsu and kickboxing matches and during the competitive period compared with the precompetitive period. This could be explained by the longer duration of bouts, the higher percentage contribution of aerobic metabolism in MMA than other combat sports and contest type differences (simulated vs. official matches). Thus, this review found significant correlations between RPE or session-RPE, [La] and HR. Particularly, there was a stronger correlation between RPE and [La] during official striking (r = 0.81) than grappling combat sports matches (r = 0.53). In addition, a variation of correlation (moderate to large) between session-RPE and HR-based methods has been reported (i.e., Edwards' training load [r ranged between 0.58 and 0.95] and Banister training impulse [r ranged between 0.52 and 0.86]). Specifically, stronger correlation was apparent in combat sport competition that required a much higher percentage contribution of aerobic metabolism (e.g., karate) and in adult athletes than anaerobic-based combat sports (e.g., taekwondo) and young athletes, respectively. Indeed, the current review highlights that the correlations between session-RPE and HR-based methods were higher during official competition than training sessions. Session-RPE was affected by participants' competitive level, the intensity of session (high vs. low), the training modalities (tactical-technical vs. technical-development vs. simulated

Kinetic evolution of the glasma and thermalization in heavy-ion collisions

International Nuclear Information System (INIS)

Huang, Xuguang; Liao, Jinfeng

2014-01-01

In relativistic heavy-ion collisions, a highly occupied gluonic matter is created shortly after initial impact, which is in a nonthermal state and often referred to as the Glasma. Successful phenomenology suggests that the glasma evolves rather quickly toward the thermal quark–gluon plasma (QGP) and a hydrodynamic behavior emerges at a very early time ~ô(1) fm/c. Exactly how such 'apparent thermalization' occurs and connects the initial conditions to the hydrodynamic onset, remains a significant challenge for theory as well as phenomenology. We briefly review various ideas and recent progress in understanding the approach of the glasma to the thermalized QGP, with an emphasis on the kinetic theory description for the evolution of such far-from-equilibrium and highly overpopulated, thus weakly-coupled yet strongly interacting glasma. (author)

Nuclear medicine methods in the assessment of acupuncture effects: a short review

International Nuclear Information System (INIS)

Souza, Deise Elisabete; Rebello, Bernardo Machado; Agostinho, Raquel Terra; Silva Filho, Reginaldo de Carvalho; Bernardo-Filho, Mario

2007-01-01

The mechanisms of acupuncture are poorly understood. In consequence, numerous investigators have conducted clinical trials to test the efficacy of acupuncture in various conditions. We have used PubMed database system to evaluate the number of publications in acupuncture and nuclear medicine procedures in the period from 1964 to 2007, using the keywords: 'nuclear medicine and acupuncture', 'SPECT and acupuncture, 'PET and acupuncture', 'scintigraphy and acupuncture, 'radionuclide and acupuncture', 'radiopharmaceutical and acupuncture', 'radioisotope and acupuncture' and 99m Tc and acupuncture'. Some papers published in English language were selected and a short review is presented The analysis of the number of publications shows that when a method is well accepted by the scientific community, as the methods used in nuclear medicine, the interest in the development of research increases. Moreover, important findings are presented when the nuclear medicine image is used to evaluate the effect of the acupuncture. (author)

Psicoterapia breve pais-bebê: revisando a literatura Short-term parent-infant psychotherapy: a review of the literature

Directory of Open Access Journals (Sweden)

Luiz Carlos Prado

2009-01-01

Full Text Available Este artigo apresenta uma revisão da literatura a respeito da psicoterapia breve pais-bebê. Inicialmente são apresentados aspectos históricos, desde o surgimento da psicoterapia breve, passando pelas formulações teóricas que enfatizaram a importância das relações iniciais pais-bebê até a constituição do campo da psicoterapia breve pais-bebê propriamente dita. Constata-se que várias abordagens compõem o panorama atual das psicoterapias pais-bebê, as quais apresentam uma ampla diversidade de referenciais teóricos e técnicos. Foram também revisados, em particular, estudos empíricos sobre a utilização dessa abordagem no contexto da depressão materna. Por fim, apresentam-se os procedimentos utilizados pelos autores deste artigo em uma pesquisa em andamento envolvendo o atendimento psicoterápico breve pais-bebê em famílias com mães deprimidas. Essa abordagem tem se mostrado efetiva na promoção de um melhor relacionamento mãe-pai-bebê na presença sintomas depressivos da mãe.This article presents a review of the literature on short-term parent-infant psychotherapy. Initially, some historical aspects are presented since the emergence of short-term psychotherapy, including the theoretical formulations that highlighted the importance of early parent-infant relationships and helped to implement the field of short-term parent-infant psychotherapy. There are several approaches to parent-infant psychotherapy, representing a broad diversity of theoretical and technical frameworks. Empirical studies were also reviewed, especially those using parent-infant psychotherapy in the context of maternal depression. Finally, the authors' experience with short-term parent-infant psychotherapy involving families with depressive mothers was presented. This approach has shown to be effective in the promotion of better mother-father-infant relationship in the presence of maternal depressive symptoms.

Three short distance structures from quantum algebras

International Nuclear Information System (INIS)

Kempf, A.

1997-01-01

Known results are reviewed and new results are given on three types of short distance structures of observables which typically appear in studies of quantum group related algebras. In particular, one of the short distance structures is shown to suggest a new mechanism for the introduction of internal symmetries

Interventions to treat premature ejaculation: a systematic review short report.

Science.gov (United States)

Cooper, Katy; Martyn-St James, Marrissa; Kaltenthaler, Eva; Dickinson, Kath; Cantrell, Anna

2015-03-01

Premature ejaculation (PE) is commonly defined as ejaculation with minimal sexual stimulation before, on or shortly after penetration and before the person wishes it. PE can be either lifelong and present since first sexual experiences (primary), or acquired (secondary), beginning later (Godpodinoff ML. Premature ejaculation: clinical subgroups and etiology. J Sex Marital Ther 1989;15:130-4). Treatments include behavioural and pharmacological interventions. To systematically review evidence for clinical effectiveness of behavioural, topical and systemic treatments for PE. The following databases were searched from inception to 6 August 2013 for published and unpublished research evidence: MEDLINE; EMBASE; Cumulative Index to Nursing and Allied Health Literature; The Cochrane Library including the Cochrane Systematic Reviews Database, Cochrane Controlled Trials Register, Database of Abstracts of Reviews of Effects and the Health Technology Assessment database; ISI Web of Science, including Science Citation Index, and the Conference Proceedings Citation Index-Science. The US Food and Drug Administration website and the European Medicines Agency (EMA) website were also searched. Randomised controlled trials (RCTs) in adult men with PE were eligible (or non-RCTs in the absence of RCTs). RCT data were extrapolated from review articles when available. The primary outcome was intravaginal ejaculatory latency time (IELT). Data were meta-analysed when possible. Other outcomes included sexual satisfaction, control over ejaculation, relationship satisfaction, self-esteem, quality of life, treatment acceptability and adverse events (AEs). A total of 103 studies (102 RCTs, 65 from reviews) were included. RCTs were available for all interventions except yoga. The following interventions demonstrated significant improvements (p < 0.05) in arithmetic mean difference in IELT compared with placebo: topical anaesthetics - eutectic mixture of local anaesthetics (EMLA(®), Astra

Mapping the evolution of scientific ideas

Energy Technology Data Exchange (ETDEWEB)

Roberts, David [Los Alamos National Laboratory; Herrera, Mark [UNIV OF MARYLAND; Gulbahce, Natali [UNIV OF BOSTON

2009-01-01

Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society PACS numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using Cfinder, an overlapping community finding algorithm, and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. The communities we identify map to known scientific fields, and their age strongly depends on t.heir size, impact and activity. Our analysis further suggests that communities that redefine themselves by merging and creating new groups of ideas tend to have more fitness as measured by the impact per paper, and hence communities with a higher fitness tend to be short-lived. The described approach to quantify the evolution of ideas may be relevant in making predictions about the future of science and how to guide its development.

Role of Short-Range Chemical Ordering in (GaN) _1–x (ZnO) _x for Photodriven Oxygen Evolution

Energy Technology Data Exchange (ETDEWEB)

Chen, Dennis P. [Department; Neuefeind, Joerg C. [Chemical; Koczkur, Kallum M. [Department; Bish, David L. [Department; Skrabalak, Sara E. [Department

2017-07-21

(GaN)1–x(ZnO)x (GZNO) is capable of visible-light driven water splitting, but its bandgap at x ≤ 0.15 (>2.7 eV) results in poor visible-light absorption. Unfortunately, methods to narrow its bandgap by incorporating higher ZnO concentrations are accompanied by extensive Urbach tailing near the absorption-edge, which is indicative of structural disorder or chemical inhomogeneities. We evaluated whether this disorder is intrinsic to the bond-length distribution in GZNO or is a result of defects introduced from the loss of Zn during nitridation. Here, the synthesis of GZNO derived from layered double hydroxide (LDH) precursors is described which minimizes Zn loss and chemical inhomogeneities and enhances visible-light absorption. The average and local atomic structures of LDH-derived GZNO were investigated using X-ray and neutron scattering and are correlated with their oxygen evolution rates. An isotope-contrasted neutron-scattering experiment was conducted in conjunction with reverse Monte Carlo (RMC) simulations. We showed that a bond-valence bias in the RMC refinements reproduces the short-range ordering (SRO) observed in structure refinements using isotope-contrasted neutron data. The findings suggest that positional disorder of cation–anion pairs in GZNO partially arises from SRO and influences local bond relaxations. Furthermore, particle-based oxygen evolution reactions (OERs) in AgNO3 solution reveal that the crystallite size of GZNO correlates more than positional disorder with oxygen evolution rate. These findings illustrate the importance of examining the local structure of multinary photocatalysts to identify dominant factors in particulate-based photodriven oxygen evolution.

The impact of rapid evolution on population dynamics in the wild: experimental test of eco-evolutionary dynamics.

Science.gov (United States)

Turcotte, Martin M; Reznick, David N; Hare, J Daniel

2011-11-01

Rapid evolution challenges the assumption that evolution is too slow to impact short-term ecological dynamics. This insight motivates the study of 'Eco-Evolutionary Dynamics' or how evolution and ecological processes reciprocally interact on short time scales. We tested how rapid evolution impacts concurrent population dynamics using an aphid (Myzus persicae) and an undomesticated host (Hirschfeldia incana) in replicated wild populations. We manipulated evolvability by creating non-evolving (single clone) and potentially evolving (two-clone) aphid populations that contained genetic variation in intrinsic growth rate. We observed significant evolution in two-clone populations whether or not they were exposed to predators and competitors. Evolving populations grew up to 42% faster and attained up to 67% higher density, compared with non-evolving control populations but only in treatments exposed to competitors and predators. Increased density also correlates with relative fitness of competing clones suggesting a full eco-evolutionary dynamic cycle defined as reciprocal interactions between evolution and density. © 2011 Blackwell Publishing Ltd/CNRS.

Nuclear medicine methods in the assessment of acupuncture effects: a short review

Energy Technology Data Exchange (ETDEWEB)

Souza, Deise Elisabete; Rebello, Bernardo Machado; Agostinho, Raquel Terra [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Lab. de Radiofarmacia Experimental; Academia Brasileira de Arte e Ciencia Oriental, Rio de Janeiro, RJ (Brazil); E-mail: deise_desouza@yahoo.com.br; Silva Filho, Reginaldo de Carvalho [Escola Brasileira de Medicina Chinesa, Sao Paulo, SP (Brazil). Centro Avancado de Pesquisas em Ciencias Orientais; Bastos, Sohaku R.C. [Academia Brasileira de Arte e Ciencia Oriental, Rio de Janeiro, RJ (Brazil); Bernardo-Filho, Mario [Instituto Nacional de Cancer (INCa), Rio de Janeiro, RJ (Brazil). Centro de Pesquisa Basica

2007-09-15

The mechanisms of acupuncture are poorly understood. In consequence, numerous investigators have conducted clinical trials to test the efficacy of acupuncture in various conditions. We have used PubMed database system to evaluate the number of publications in acupuncture and nuclear medicine procedures in the period from 1964 to 2007, using the keywords: 'nuclear medicine and acupuncture', 'SPECT and acupuncture, 'PET and acupuncture', 'scintigraphy and acupuncture, 'radionuclide and acupuncture', 'radiopharmaceutical and acupuncture', 'radioisotope and acupuncture' and {sup 99m}Tc and acupuncture'. Some papers published in English language were selected and a short review is presented The analysis of the number of publications shows that when a method is well accepted by the scientific community, as the methods used in nuclear medicine, the interest in the development of research increases. Moreover, important findings are presented when the nuclear medicine image is used to evaluate the effect of the acupuncture. (author)

Computation of a long-time evolution in a Schroedinger system

International Nuclear Information System (INIS)

Girard, R.; Kroeger, H.; Labelle, P.; Bajzer, Z.

1988-01-01

We compare different techniques for the computation of a long-time evolution and the S matrix in a Schroedinger system. As an application we consider a two-nucleon system interacting via the Yamaguchi potential. We suggest computation of the time evolution for a very short time using Pade approximants, the long-time evolution being obtained by iterative squaring. Within the technique of strong approximation of Moller wave operators (SAM) we compare our calculation with computation of the time evolution in the eigenrepresentation of the Hamiltonian and with the standard Lippmann-Schwinger solution for the S matrix. We find numerical agreement between these alternative methods for time-evolution computation up to half the number of digits of internal machine precision, and fairly rapid convergence of both techniques towards the Lippmann-Schwinger solution

Massage therapy has short-term benefits for people with common musculoskeletal disorders compared to no treatment: a systematic review

Directory of Open Access Journals (Sweden)

Diederik C Bervoets

2015-07-01

Full Text Available Question: Is massage therapy effective for people with musculoskeletal disorders compared to any other treatment or no treatment? Design: Systematic review of randomised clinical trials. Participants: People with musculoskeletal disorders. Interventions: Massage therapy (manual manipulation of the soft tissues as a stand-alone intervention. Outcome: The primary outcomes were pain and function. Results: The 26 eligible randomised trials involved 2565 participants. The mean sample size was 95 participants (range 16 to 579 per study; 10 studies were considered to be at low risk of bias. Overall, low-to-moderate-level evidence indicated that massage reduces pain in the short term compared to no treatment in people with shoulder pain and osteoarthritis of the knee, but not in those with low back pain or neck pain. Furthermore, low-to-moderate-level evidence indicated that massage improves function in the short term compared to no treatment in people with low back pain, knee arthritis or shoulder pain. Low-to-very-low-level evidence from single studies indicated no clear benefits of massage over acupuncture, joint mobilisation, manipulation or relaxation therapy in people with fibromyalgia, low back pain and general musculoskeletal pain. Conclusions: Massage therapy, as a stand-alone treatment, reduces pain and improves function compared to no treatment in some musculoskeletal conditions. When massage is compared to another active treatment, no clear benefit was evident. [Bervoets DC, Luijsterburg PAJ, Alessie JJN, Buijs MJ, Verhagen AP (2015 Massage therapy has short-term benefits for people with common musculoskeletal disorders compared to no treatment: a systematic review. Journal of Physiotherapy 61: 106–116

Review of the evolution of insecticide resistance in main malaria vectors in Cameroon from 1990 to 2017.

Science.gov (United States)

Antonio-Nkondjio, Christophe; Sonhafouo-Chiana, N; Ngadjeu, C S; Doumbe-Belisse, P; Talipouo, A; Djamouko-Djonkam, L; Kopya, E; Bamou, R; Awono-Ambene, P; Wondji, Charles S

2017-10-10

Malaria remains a major public health threat in Cameroon and disease prevention is facing strong challenges due to the rapid expansion of insecticide resistance in vector populations. The present review presents an overview of published data on insecticide resistance in the main malaria vectors in Cameroon to assist in the elaboration of future and sustainable resistance management strategies. A systematic search on mosquito susceptibility to insecticides and insecticide resistance in malaria vectors in Cameroon was conducted using online bibliographic databases including PubMed, Google and Google Scholar. From each peer-reviewed paper, information on the year of the study, mosquito species, susceptibility levels, location, insecticides, data source and resistance mechanisms were extracted and inserted in a Microsoft Excel datasheet. The data collected were then analysed for assessing insecticide resistance evolution. Thirty-three scientific publications were selected for the analysis. The rapid evolution of insecticide resistance across the country was reported from 2000 onward. Insecticide resistance was highly prevalent in both An. gambiae (s.l.) and An. funestus. DDT, permethrin, deltamethrin and bendiocarb appeared as the most affected compounds by resistance. From 2000 to 2017 a steady increase in the prevalence of kdr allele frequency was noted in almost all sites in An. gambiae (s.l.), with the L1014F kdr allele being the most prevalent. Several detoxification genes (particularly P450 monooxygenase) were associated with DDT, pyrethroids and bendiocarb resistance. In An. funestus, resistance to DDT and pyrethroids was mainly attributed to the 119F-GSTe2 metabolic resistance marker and over-expression of P450 genes whereas the 296S-RDL mutation was detected in dieldrin-resistant An. funestus. The review provides an update of insecticide resistance status in malaria vector populations in Cameroon and stresses the need for further actions to reinforce malaria

Design and production of a short 2D animated film

OpenAIRE

Prusnik, Petra

2014-01-01

Design and production of a short 2D animated film The thesis aims at analysing animation, the process of creating an ani- mated film with its technical and compositional details as well as show the process of making a short 2D animated movie with Toon Boom Studio. It is composed of theoretical and practical part. The theoretical part of this thesis consists of the definition of the term "animation", a quick overview of its history and evolution, and an in-depth look into var...

A systematic review of social, economic and diplomatic aspects of short-term medical missions.

Science.gov (United States)

Caldron, Paul H; Impens, Ann; Pavlova, Milena; Groot, Wim

2015-09-15

Short-term medical missions (STMMs) represent a grass-roots form of aid, transferring medical services rather than funds or equipment. The objective of this paper is to review empirical studies on social, economic and diplomatic aspects of STMMs. A systematic literature review was conducted by searching PubMed and EBSCOhost for articles published from 1947-2014 about medical missions to lower and middle income countries (LMICs). Publications focused on military, disaster and dental service trips were excluded. A data extraction process was used to identify publications relevant to our objective stated above. PubMed and EBSCOhost searches provided 4138 and 3262 articles respectively for review. Most articles that provide useful information have appeared in the current millennium and are found in focused surgical journals. Little attention is paid to aspects of volunteerism, altruism and philanthropy related to STMM activity in the literature reviewed (1 article). Evidence of professionalization remains scarce, although elements including guidelines and tactical instructions have been emerging (27 articles). Information on costs (10 articles) and commentary on the relevance of market forces (1 article) are limited. Analyses of spill-over effects, i.e., changing attitudes of physicians or their communities towards aid, and characterizations of STMMs as meaningful foreign aid or strategic diplomacy are few (4 articles). The literature on key social, economic and diplomatic aspects of STMMs and their consequences is sparse. Guidelines, tactical instructions and attempts at outcome measures are emerging that may better professionalize the otherwise unregulated activity. A broader discussion of these key aspects may lead to improved accountability and intercultural professionalism to accompany medical professionalism in STMM activity.

Bunching phase evolution of short-pulse FEL oscillator system

CERN Document Server

Song, S B; Choi, D I

2000-01-01

We studied numerically the short-pulse FEL oscillator system using properly defined bunching phase theta sub B and PSI sub B. In stable operation, we have found that the optical field 'locks' the phase to pi/2 at the trailing edge, which gives the maximum gain. Moreover, electrons can be detrapped from ponderomotive bucket due to the spatial variation of the optical field, and this detrapping effect is a major cause of the limit cycle oscillation of the system. The 'bump' of the output power during the amplification usually exists at the near-perfect cavity synchronism regime, which can be explained as the change of the matching condition between electron micropulse and optical pulse.

Insights into early extracellular matrix evolution: spongin short chain collagen-related proteins are homologous to basement membrane type IV collagens and form a novel family widely distributed in invertebrates.

Science.gov (United States)

Aouacheria, Abdel; Geourjon, Christophe; Aghajari, Nushin; Navratil, Vincent; Deléage, Gilbert; Lethias, Claire; Exposito, Jean-Yves

2006-12-01

Collagens are thought to represent one of the most important molecular innovations in the metazoan line. Basement membrane type IV collagen is present in all Eumetazoa and was found in Homoscleromorpha, a sponge group with a well-organized epithelium, which may represent the first stage of tissue differentiation during animal evolution. In contrast, spongin seems to be a demosponge-specific collagenous protein, which can totally substitute an inorganic skeleton, such as in the well-known bath sponge. In the freshwater sponge Ephydatia mülleri, we previously characterized a family of short-chain collagens that are likely to be main components of spongins. Using a combination of sequence- and structure-based methods, we present evidence of remote homology between the carboxyl-terminal noncollagenous NC1 domain of spongin short-chain collagens and type IV collagen. Unexpectedly, spongin short-chain collagen-related proteins were retrieved in nonsponge animals, suggesting that a family related to spongin constitutes an evolutionary sister to the type IV collagen family. Formation of the ancestral NC1 domain and divergence of the spongin short-chain collagen-related and type IV collagen families may have occurred before the parazoan-eumetazoan split, the earliest divergence among extant animal phyla. Molecular phylogenetics based on NC1 domain sequences suggest distinct evolutionary histories for spongin short-chain collagen-related and type IV collagen families that include spongin short-chain collagen-related gene loss in the ancestors of Ecdyzosoa and of vertebrates. The fact that a majority of invertebrates encodes spongin short-chain collagen-related proteins raises the important question to the possible function of its members. Considering the importance of collagens for animal structure and substratum attachment, both families may have played crucial roles in animal diversification.

Sarcomatoid carcinoma of kidney, presenting with leucocytosis as paraneoplastic syndrome: A case report and short review

Directory of Open Access Journals (Sweden)

Joydeep Ghosh

2017-01-01

Full Text Available Renal cell carcinoma is the ninth most common malignancy. The commonest histopathological type is clear cell carcinoma. The occurrence of sarcomatoid carcinoma is very rare and confers a very poor prognosis. Only 10-20% patients present with paraneoplastic syndromes. Out of the common paraneoplastic syndromes, leucocytosis is one of the least reported. Here, we present a case of sarcomatoid carcinoma of kidney who presented with low-grade fever and leucocytosis, followed by a short review of literature. This is one of the rare situations where a rare histologic variant presents with a rare finding.

Comments on the evolution and origin of cataclysmic binaries

International Nuclear Information System (INIS)

Whyte, C.A.; Eggleton, P.P.

1980-01-01

Aspects of the observational data on cataclysmic binaries are discussed and possible correlations between type of behaviour and binary period are noted. A gap between 2 and 3 hr in binary periods is judged to be real. A simple numerical procedure for evolving Roche-lobe-filling stars is described, and applied to white dwarf-red dwarf binaries for various mass loss and angular momentum loss mechanisms, and initial conditions. The results, in which the short-time-scale behaviour of the systems is ignored, are classified into four modes of evolution: normal, nuclear evolution dominated, angular momentum loss dominated and hydrodynamical. The clustering below 2 hr is interpreted in terms of evolution following the hydrodynamical mode, and it is suggested that both stars in such systems are of low mass. This may be the commonest type of cataclysmic binary. A possible explanation for the apparent clustering of classical novae to periods of 3 to 5 hr is given, and evolutionary schemes for cataclysmic binaries outlined. It is suggested that the short-period systems (approximately < 2 hr) arise mainly from late case B mass transfer in the original binary and the longer period systems mainly from case C. (author)

Short-term energy outlook, annual supplement 1994

International Nuclear Information System (INIS)

1994-08-01

The Short-Term Energy Outlook Annual Supplement (Supplement) is published once a year as a complement to the Short-Term Energy Outlook (Outlook), Quarterly Projections. The purpose of the Supplement is to review the accuracy of the forecasts published in the Outlook, make comparisons with other independent energy forecasts, and examine current energy topics that affect the forecasts

Short-term energy outlook annual supplement, 1993

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-08-06

The Short-Term Energy Outlook Annual Supplement (supplement) is published once a year as a complement to the Short-Term Energy Outlook (Outlook), Quarterly Projections. The purpose of the Supplement is to review the accuracy of the forecasts published in the Outlook, make comparisons with other independent energy forecasts, and examine current energy topics that affect the forecasts.

Modelling microstructural evolution under irradiation

International Nuclear Information System (INIS)

Tikare, V.

2015-01-01

Microstructural evolution of materials under irradiation is characterised by some unique features that are not typically present in other application environments. While much understanding has been achieved by experimental studies, the ability to model this microstructural evolution for complex materials states and environmental conditions not only enhances understanding, it also enables prediction of materials behaviour under conditions that are difficult to duplicate experimentally. Furthermore, reliable models enable designing materials for improved engineering performance for their respective applications. Thus, development and application of mesoscale microstructural model are important for advancing nuclear materials technologies. In this chapter, the application of the Potts model to nuclear materials will be reviewed and demonstrated, as an example of microstructural evolution processes. (author)

Evolution of Isolated Neutron Stars

OpenAIRE

Popov, S. B.

2001-01-01

In this paper we briefly review our recent results on evolution and properties of isolated neutron stars (INSs) in the Galaxy. As the first step we discuss stochastic period evolution of INSs. We briefly discuss how an INS's spin period evolves under influence of interaction with turbulized interstellar medium. To investigate statistical properties of the INS population we calculate a {\\it census} of INSs in our Galaxy. Then we show that for exponential field decay the range of minimum value ...

Sales Forecasting for Fashion Retailing Service Industry: A Review

Directory of Open Access Journals (Sweden)

Na Liu

2013-01-01

Full Text Available Sales forecasting is crucial for many retail operations. It is especially critical for the fashion retailing service industry in which product demand is very volatile and product’s life cycle is short. This paper conducts a comprehensive literature review and selects a set of papers in the literature on fashion retail sales forecasting. The advantages and the drawbacks of different kinds of analytical methods for fashion retail sales forecasting are examined. The evolution of the respective forecasting methods over the past 15 years is revealed. Issues related to real-world applications of the fashion retail sales forecasting models and important future research directions are discussed.

Origin and evolution of SINEs in eukaryotic genomes.

Science.gov (United States)

Kramerov, D A; Vassetzky, N S

2011-12-01

Short interspersed elements (SINEs) are one of the two most prolific mobile genomic elements in most of the higher eukaryotes. Although their biology is still not thoroughly understood, unusual life cycle of these simple elements amplified as genomic parasites makes their evolution unique in many ways. In contrast to most genetic elements including other transposons, SINEs emerged de novo many times in evolution from available molecules (for example, tRNA). The involvement of reverse transcription in their amplification cycle, huge number of genomic copies and modular structure allow variation mechanisms in SINEs uncommon or rare in other genetic elements (module exchange between SINE families, dimerization, and so on.). Overall, SINE evolution includes their emergence, progressive optimization and counteraction to the cell's defense against mobile genetic elements.

Nurses' contribution to short-term humanitarian care in low- to middle-income countries: An integrative review of the literature.

Science.gov (United States)

Dawson, Sonja; Elliott, Doug; Jackson, Debra

2017-12-01

To appraise the literature related to voluntary humanitarian work provided by international nurses in low- to middle-income countries. Nurses and other health professionals are engaged with both governmental and nongovernmental organisations to provide care within international humanitarian relief and development contexts. Current literature describes accounts of charitable health professional activity within short-term health-focused humanitarian trips; however, there is minimal research describing the care that nurses provide and the professional roles and tasks they fulfil whilst participating in international volunteer healthcare service. Integrative review. A search of articles published between 1995-2015 was conducted using seven bibliographic databases. Inclusion criteria incorporated nurses and allied health professionals' involvement in a volunteer short-term medical team capacity. Papers describing military and/or disaster response with a service-learning focus were excluded. Nineteen papers were selected for review, description and discussion of findings. Findings revealed limited data describing the care nurses provide and the professional roles and tasks they fulfil within the context of international humanitarian short-term medical trips. Issues raised included a description of demographic data regarding participants and sending agencies, motivation for volunteer participation, perceptions of effectiveness of particular programmes and sustainability issues related to cultural, ethical or moral obligations of foreign health professionals working in a low- to middle-income countries. Study findings highlighted that although nurses are recruited and participate in health-focused humanitarian activities in low- to middle-income countries, there is extremely limited documented research about the amount and type of care that nurses specifically provide in this context. Furthermore, when identified, it is most often hidden within studies outlining services

Intestino Corto Short bowel syndrome

Directory of Open Access Journals (Sweden)

María Matilde Socarrás Suárez

2004-06-01

Full Text Available El intestino corto está asociado a pérdida o disfunción del intestino delgado por resección del mismo, que causa diarreas, tránsito intestinal acelerado, malabsorción intestinal, y eventualmente la pérdida de peso y el desgaste muscular. El objetivo de este trabajo fue actualizar el conocimiento acerca de este síndrome. Se realiza una revisión del tema de intestino corto donde se refiere a su definición, causas fundamentales frecuentes e infrecuentes en el niño y en el adulto, cómo se adapta el intestino a la resección de diferentes extensiones, las funciones del íleon terminal. Se hacen una valoración clínica inicial, con el interrogatorio médico, revisión minuciosa de la historia clínica para cuantificar la capacidad de absorción. Se habla de los síntomas y signos de deficiencia nutricional. Se explican las estrategias del tratamiento, que tienen 3 etapas de evolución clínica. Se concluye que se indica la dietoterapia adecuada según el estado nutricional del paciente y la resección intestinal realizada, evitando las complicaciones para lograr una calidad máxima de vidaShort bowel is associated with loss or dysfunction of the small bowel due to its resection, which causes diarrheas, accelerated intestinal transit, intestinal malabsorption and, eventually, weight loss ansd muscular waste. The objective of this paper was to update knowledge about this syndrome. A review of the short intestine topic is made, making reference to its definition, common and uncommon main cuases in the child and adult, how the bowel adapts itslef to resection of different extensions, and the functions of the terminal ileum. An initial clinical assessment is made with the medical questionnaire and a detailed review of the medical history to quantify the absorption capacity. The symptoms and signs of nutritional deficiency are dealt with. The strategies of the treatment consisting of 3 stages of clinical evolution are explained. It is concluded

Enzyme (re)design: lessons from natural evolution and computation.

Science.gov (United States)

Gerlt, John A; Babbitt, Patricia C

2009-02-01

The (re)design of enzymes to catalyze 'new' reactions is a topic of considerable practical and intellectual interest. Directed evolution (random mutagenesis followed by screening/selection) has been used widely to identify novel biocatalysts. However, 'rational' approaches using either natural divergent evolution or computational predictions based on chemical principles have been less successful. This review summarizes recent progress in evolution-based and computation-based (re)design.

Soil CO2 evolution: Response from arginine additions

Science.gov (United States)

Short-term response of soil C mineralization following drying/rewetting has been proposed as an indicator of soil microbial activity. Houston Black clay was amended with four rates of arginine to vary microbial response and keep other soil properties constant. The evolution of CO2 during one and thr...

The population ecology of contemporary adaptations: what empirical studies reveal about the conditions that promote adaptive evolution.

Science.gov (United States)

Reznick, D N; Ghalambor, C K

2001-01-01

Under what conditions might organisms be capable of rapid adaptive evolution? We reviewed published studies documenting contemporary adaptations in natural populations and looked for general patterns in the population ecological causes. We found that studies of contemporary adaptation fall into two general settings: (1) colonization of new environments that established newly adapted populations, and (2) local adaptations within the context of a heterogeneous environments and metapopulation structure. Local ecological processes associated with colonizations and introductions included exposure to: (1) a novel host or food resource; (2) a new biophysical environment; (3) a new predator community; and (4) a new coexisting competitor. The new environments that were colonized often had depauperate communities, sometimes because of anthropogenic disturbance. Local adaptation in heterogeneous environments was also often associated with recent anthropogenic changes, such as insecticide and herbicide resistance, or industrial melanism. A common feature of many examples is the combination of directional selection with at least a short-term opportunity for population growth. We suggest that such opportunities for population growth may be a key factor that promotes rapid evolution, since directional selection might otherwise be expected to cause population decline and create the potential for local extinction, which is an ever-present alternative to local adaptation. We also address the large discrepancy between the rate of evolution observed in contemporary studies and the apparent rate of evolution seen in the fossil record.

IUE spectrophotometry of the DA4 primary in the short-period white dwarf-red dwarf spectroscopic binary Case 1

Science.gov (United States)

Sion, E. M.; Guinan, E. F.; Wesemael, F.

1984-01-01

Low-resolution ultraviolet International Ultraviolet Explorer spectra of the DA white dwarf Case 1 are presented. The spectra show the presence of the 1400 A feature, already discovered in several other DA stars, and of a shallower trough in the 1550-1700 A range. A model atmosphere analysis of the ultraviolet energy distribution of the Ly-alpha red wing yields T(e) = 13,000 + or - 500 K. Possible interpretations of the 1400 A feature are reviewed. Case 1 is the coolest white dwarf found in a short-period, detached white dwarf-red dwarf binary, and its cooling time is consistent with estimates of the efficiency of angular momentum removal mechanisms in the phases subsequent to common envelope binary evolution.

Natural gas tariffing principles in France and tariffs evolution

International Nuclear Information System (INIS)

2001-12-01

This short document explains the principle of gas tariffing in France which is based on the marginal cost of development and on the equality between consumers. The evolution of industrial and domestic gas tariffs since 1997 is summarized in tables. (J.S.)

Heavy quarkonium production at collider energies: Factorization and evolution

Science.gov (United States)

Kang, Zhong-Bo; Ma, Yan-Qing; Qiu, Jian-Wei; Sterman, George

2014-08-01

We present a perturbative QCD factorization formalism for inclusive production of heavy quarkonia of large transverse momentum, pT at collider energies, including both leading power (LP) and next-to-leading power (NLP) behavior in pT. We demonstrate that both LP and NLP contributions can be factorized in terms of perturbatively calculable short-distance partonic coefficient functions and universal nonperturbative fragmentation functions, and derive the evolution equations that are implied by the factorization. We identify projection operators for all channels of the factorized LP and NLP infrared safe short-distance partonic hard parts, and corresponding operator definitions of fragmentation functions. For the NLP, we focus on the contributions involving the production of a heavy quark pair, a necessary condition for producing a heavy quarkonium. We evaluate the first nontrivial order of evolution kernels for all relevant fragmentation functions, and discuss the role of NLP contributions.

Short-lasting headache syndromes and treatment options.

Science.gov (United States)

Rozen, Todd D

2004-08-01

A number of primary headache syndromes are marked by their short duration of pain. Many of these syndromes have their own unique treatment, so they must be recognized by practicing physicians. In this article, a number of the short-lasting headache disorders are reviewed, including chronic paroxysmal hemicrania, SUNCT syndrome, hypnic headache, exploding head syndrome, primary stabbing headache, and cough headache.

Isobar configurations in nuclei and short range correlations

CERN Document Server

Weber, H J

1979-01-01

Recent results on short range correlations and isobar configurations are reviewed, and in particular a unitary version of the isobar model, coupling constants and rho -meson transition potentials, a comparison with experiments, the CERN N*-knockout from /sup 4/He, QCD and the NN interaction of short range. (42 refs).

A review of the irradiation evolution of dispersed oxide nanoparticles in the b.c.c. Fe-Cr system: Current understanding and future directions

Energy Technology Data Exchange (ETDEWEB)

Wharry, Janelle P., E-mail: jwharry@purdue.edu [Purdue University, 400 Central Drive, West Lafayette, IN 47907 (United States); Swenson, Matthew J.; Yano, Kayla H. [Boise State University, 1910 University Drive, Boise, ID 83725 (United States)

2017-04-01

Thus far, a number of studies have investigated the irradiation evolution of oxide nanoparticles in b.c.c. Fe-Cr based oxide dispersion strengthened (ODS) alloys. But given the inconsistent experimental conditions, results have been widely variable and inconclusive. Crystal structure and chemistry changes differ from experiment to experiment, and the total nanoparticle volume fraction has been observed to both increase and decrease. Furthermore, there has not yet been a comprehensive review of the archival literature. In this paper, we summarize the existing studies on nanoparticle irradiation evolution. We note significant observations with respect to oxide nanoparticle crystallinity, composition, size, and number density. We discuss four possible contributing mechanisms for nanoparticle evolution: ballistic dissolution, Ostwald ripening, irradiation-enhanced diffusion, and homogeneous nucleation. Finally, we propose future directions to achieve a more comprehensive understanding of irradiation effects on oxide nanoparticles in ODS alloys.

Experimental evolution in biofilm populations

Science.gov (United States)

Steenackers, Hans P.; Parijs, Ilse; Foster, Kevin R.; Vanderleyden, Jozef

2016-01-01

Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques. PMID:26895713

Short hookwire placement under imaging guidance before thoracic surgery: A review.

Science.gov (United States)

Iguchi, T; Hiraki, T; Matsui, Y; Fujiwara, H; Masaoka, Y; Uka, M; Gobara, H; Toyooka, S; Kanazawa, S

2018-05-07

During video-assisted thoracic surgery (VATS), localization is sometimes needed to detect a target lesion that is too small and/or too far from the pleura. In 1995, Kanazawa et al. developed short hookwire and suture system. Since then, this system has been placed often for selected targets before VATS in Japan. This short hookwire and suture system is a representative preoperative localization method and the placement procedure is well-established. Its placement success rates are very high (range: 97.6%-99.6%), and dislodgement of this short hookwire rarely occurs with an incidence of 0.4%-2.5%. The most common complication of short hookwire placement is pneumothorax (incidence: 32.1%-68.1%), followed by pulmonary hemorrhage (incidence: 8.9%-41.6%). Complications are frequent; however, most complications are minor and asymptomatic. Copyright © 2018 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.

The relation between stellar evolution and cosmology

International Nuclear Information System (INIS)

Tayler, R.J.

1984-01-01

Observations of star clusters combined with the theory of stellar evolution enable us to estimate the ages of stars while cosmological observations and theories give us a value for the age of the Universe. This is the most important interaction between cosmology and stellar evolution because it is clearly necessary that stars are younger than the Universe. Stellar evolution also plays an important role in relating the present chemical composition of the Universe to its original composition. The author restricts the review to a discussion of the relation between stellar evolution and the big bang cosmological theory because there is such a good qualitative agreement between the hot big bang theory and observations. (Auth.)

Within-Host Evolution of Human Influenza Virus.

Science.gov (United States)

Xue, Katherine S; Moncla, Louise H; Bedford, Trevor; Bloom, Jesse D

2018-03-10

The rapid global evolution of influenza virus begins with mutations that arise de novo in individual infections, but little is known about how evolution occurs within hosts. We review recent progress in understanding how and why influenza viruses evolve within human hosts. Advances in deep sequencing make it possible to measure within-host genetic diversity in both acute and chronic influenza infections. Factors like antigenic selection, antiviral treatment, tissue specificity, spatial structure, and multiplicity of infection may affect how influenza viruses evolve within human hosts. Studies of within-host evolution can contribute to our understanding of the evolutionary and epidemiological factors that shape influenza virus's global evolution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chameleonic Theories: A Short Review

Directory of Open Access Journals (Sweden)

Andrea Zanzi

2015-12-01

Full Text Available In the chameleon mechanism, a field (typically scalar has a mass that depends on the matter density of the environment: the larger is the matter density, the larger is the mass of the chameleon. We briefly review some aspects of chameleonic theories. In particular, in a typical class of these theories, we discuss the lagrangian, the role of conformal transformations, the equation of motion and the thin-shell effect. We also discuss f ( R theories and chameleonic quantum gravity.

PERFORMANCE EVALUATION: LITERATURE REVIEW AND TIME EVOLUTION.

Directory of Open Access Journals (Sweden)

Pintea Mirela-Oana

2012-07-01

Full Text Available Performance evaluation of an economic entity requires approaching several criteria, such as industry and economic entity type, managerial and entrepreneurial strategy, competitive environment, human and material resources available, using a system of appropriate performance indicators for this purpose.The exigencies of communication occurred on the growing number of phenomena that marked the global economy in recent decades (internationalization and relocation of business crises and turmoil in financial markets, demand performance measurement to be made in a comprehensive way by financial and non-financial criteria. Indicators are measures of performance used by management to measure, report and improve performance of the economic entity. The relationship between indicators and management is ensured by the existence of performance measurement systems. Studies to date indicate that economic entities using balanced performance measurement systems as a key management tool registered superior performance compared to entities not using such systems. This study attempts to address the issue of performance evaluation by presenting opinions of different authors concerning the process of performance measurement and to present, after revising the literature, the evolution of the performance evaluation systems. We tried to do this literature review because sustainable development and, therefore, globalization require new standards of performance that exceeds the economic field, both for domestic companies as well as international ones. So, these standards should be integrated into corporate strategy development to ensure sustainability of activities undertaken by harmonizing the economic, social and environmental objectives. To assess the performance of economic entities it is required that performance evaluation to be done with a balanced multidimensional system, including both financial ratios and non-financial indicators in order to reduce the limits of

The Semantic Drift of Quotations in Blogspace: A Case Study in Short-Term Cultural Evolution.

Science.gov (United States)

Lerique, Sébastien; Roth, Camille

2018-01-01

We present an empirical case study that connects psycholinguistics with the field of cultural evolution, in order to test for the existence of cultural attractors in the evolution of quotations. Such attractors have been proposed as a useful concept for understanding cultural evolution in relation with individual cognition, but their existence has been hard to test. We focus on the transformation of quotations when they are copied from blog to blog or media website: by coding words with a number of well-studied lexical features, we show that the way words are substituted in quotations is consistent (a) with the hypothesis of cultural attractors and (b) with known effects of the word features. In particular, words known to be harder to recall in lists have a higher tendency to be substituted, and words easier to recall are produced instead. Our results support the hypothesis that cultural attractors can result from the combination of individual cognitive biases in the interpretation and reproduction of representations. Copyright © 2017 Cognitive Science Society, Inc.

Prediction and phylogenetic analysis of mammalian short interspersed elements (SINEs).

Science.gov (United States)

Rogozin, I B; Mayorov, V I; Lavrentieva, M V; Milanesi, L; Adkison, L R

2000-09-01

The presence of repetitive elements can create serious problems for sequence analysis, especially in the case of homology searches in nucleotide sequence databases. Repetitive elements should be treated carefully by using special programs and databases. In this paper, various aspects of SINE (short interspersed repetitive element) identification, analysis and evolution are discussed.

Extended Kalman Filter framework for forecasting shoreline evolution

Science.gov (United States)

Long, Joseph; Plant, Nathaniel G.

2012-01-01

A shoreline change model incorporating both long- and short-term evolution is integrated into a data assimilation framework that uses sparse observations to generate an updated forecast of shoreline position and to estimate unobserved geophysical variables and model parameters. Application of the assimilation algorithm provides quantitative statistical estimates of combined model-data forecast uncertainty which is crucial for developing hazard vulnerability assessments, evaluation of prediction skill, and identifying future data collection needs. Significant attention is given to the estimation of four non-observable parameter values and separating two scales of shoreline evolution using only one observable morphological quantity (i.e. shoreline position).

Cognition and the evolution of camouflage.

Science.gov (United States)

Skelhorn, John; Rowe, Candy

2016-02-24

Camouflage is one of the most widespread forms of anti-predator defence and prevents prey individuals from being detected or correctly recognized by would-be predators. Over the past decade, there has been a resurgence of interest in both the evolution of prey camouflage patterns, and in understanding animal cognition in a more ecological context. However, these fields rarely collide, and the role of cognition in the evolution of camouflage is poorly understood. Here, we review what we currently know about the role of both predator and prey cognition in the evolution of prey camouflage, outline why cognition may be an important selective pressure driving the evolution of camouflage and consider how studying the cognitive processes of animals may prove to be a useful tool to study the evolution of camouflage, and vice versa. In doing so, we highlight that we still have a lot to learn about the role of cognition in the evolution of camouflage and identify a number of avenues for future research. © 2016 The Author(s).

Frost evolution in tailings

International Nuclear Information System (INIS)

1991-04-01

A review was carried out on the physical and thermal mechanisms of permafrost evaluation in soils and uranium tailings. The primary mechanism controlling permafrost evolution is conductive heat transfer with the latent heat of fusion of water being liberated as phase change occurs. Depending on the soil properties and freezing rate, pore water can be expelled from the frost front or pore water can migrate towards the frost front. Solute redistribution may occur as the frost front penetrates into the soil. The rate of frost penetration is a function of the thermal properties of the tailings and the climatic conditions. Computer modelling programmes capable of modelling permafrost evolution were reviewed. The GEOTHERM programme was selected as being the most appropriate for this study. The GEOTHERM programme uses the finite element method of thermal analysis. The ground surface temperature is determined by solving the energy balance equations a the ground surface. The GEOTHERM programme was used to simulate the permafrost evolution in the Key Lake Mine tailings located in north central Saskatchewan. The analyses indicated that the existing frozen zones in the tailing pond will eventually thaw if an average snow depth covers the tailings. Hundreds of years are required to thaw the tailings. If minimal snow cover is present the extent of the frozen zone in the tailings will increase

Review of evolution of tunnel position in anterior cruciate ligament reconstruction.

Science.gov (United States)

Rayan, Faizal; Nanjayan, Shashi Kumar; Quah, Conal; Ramoutar, Darryl; Konan, Sujith; Haddad, Fares S

2015-03-18

Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established.

Evolution in close binary systems

International Nuclear Information System (INIS)

Yungel'son, L.R.; Masevich, A.G.

1983-01-01

Duality is the property most typical of stars. If one investigates how prevalent double stars are, making due allowance for selection effects, one finds that as many as 90 percent of all stars are paired. Contrary to tradition it is single stars that are out of the ordinary, and as will be shown presently even some of these may have been formed by coalescence of the members of binary systems. This review deals with the evolution of close binaries, defined as double-star systems whose evolution entails exchange of material between the two components

Human contribution in the geomorphologic changes and short-term evolution of the Colombian Caribbean coast

International Nuclear Information System (INIS)

Rangel B, Nelson

2009-01-01

The recent coastline evolution in the Colombian Caribbean coast is associated, among other causes, with an obvious anthropogenic influence over the littoral morphology. Along the 30 coastal cities of this region, there are areas intervened by the man, that the same time are affected by significant setbacks in their coastline. The predominant erosive trend was influenced and affected, in a lot of cases, by a chaotic human expansion and their troubles associated. General analyses in some areas allowed identify the anthropic actions, their influence and negative impacts over the morphology and recent evolution of the littoral.

Serous papillary cystadenofibroma of the fallopian tube: A case report and short review of literature

Directory of Open Access Journals (Sweden)

Yasmeen Khatib

2015-01-01

Full Text Available Serous papillary cystadenofibromas (SPCAFs of the fallopian tube are very rare benign tumors of the female genital tract. They are usually asymptomatic and are found incidentally. Until now, only 18 cases of this tumor have been reported in the world literature. We report a case of SPCAF of the left fallopian tube in a 30-year-old female who presented with a large abdominal mass and pain. On computed tomography, a diagnosis of ovarian neoplasm was given. However, during surgery the tumor was found to arise from the fallopian tube and was treated with tubal cystectomy with sparing of the ovary. We present this unique case on account of its rarity, unusual presentation, and huge size along with a short review of literature.

Ten Years Evidence-Based High-Tech Acupuncture—A Short Review of Peripherally Measured Effects

Directory of Open Access Journals (Sweden)

Gerhard Litscher

2009-01-01

Full Text Available Since 1997, the Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine of Graz Medical University has been dealing with the demystification of acupuncture and examining, using non-invasive methods, how different stimulation modalities (manual needle acupuncture, laserneedle acupuncture and electro acupuncture affect peripheral and central functions. Laser is also an important instrument for acupuncture. One only needs to mention the treatment of children or of patients with needle phobia. The laserneedle acupuncture, which was examined scientifically for the first time in Graz, represents a new painless acupuncture method for which up to ten laserneedles are glued to the skin, but not stuck into it. This first part of the short review article summarizes some of the peripherally measured effects of acupuncture obtained at the Medical University of Graz within the last 10 years.

Spectral shifts of mammalian ultraviolet-sensitive pigments (short wavelength-sensitive opsin 1) are associated with eye length and photic niche evolution.

Science.gov (United States)

Emerling, Christopher A; Huynh, Hieu T; Nguyen, Minh A; Meredith, Robert W; Springer, Mark S

2015-11-22

Retinal opsin photopigments initiate mammalian vision when stimulated by light. Most mammals possess a short wavelength-sensitive opsin 1 (SWS1) pigment that is primarily sensitive to either ultraviolet or violet light, leading to variation in colour perception across species. Despite knowledge of both ultraviolet- and violet-sensitive SWS1 classes in mammals for 25 years, the adaptive significance of this variation has not been subjected to hypothesis testing, resulting in minimal understanding of the basis for mammalian SWS1 spectral tuning evolution. Here, we gathered data on SWS1 for 403 mammal species, including novel SWS1 sequences for 97 species. Ancestral sequence reconstructions suggest that the most recent common ancestor of Theria possessed an ultraviolet SWS1 pigment, and that violet-sensitive pigments evolved at least 12 times in mammalian history. We also observed that ultraviolet pigments, previously considered to be a rarity, are common in mammals. We then used phylogenetic comparative methods to test the hypotheses that the evolution of violet-sensitive SWS1 is associated with increased light exposure, extended longevity and longer eye length. We discovered that diurnal mammals and species with longer eyes are more likely to have violet-sensitive pigments and less likely to possess UV-sensitive pigments. We hypothesize that (i) as mammals evolved larger body sizes, they evolved longer eyes, which limited transmittance of ultraviolet light to the retina due to an increase in Rayleigh scattering, and (ii) as mammals began to invade diurnal temporal niches, they evolved lenses with low UV transmittance to reduce chromatic aberration and/or photo-oxidative damage. © 2015 The Author(s).

Short- and long-term outcomes of metformin compared with insulin alone in pregnancy: a systematic review and meta-analysis.

Science.gov (United States)

Butalia, S; Gutierrez, L; Lodha, A; Aitken, E; Zakariasen, A; Donovan, L

2017-01-01

To assess the short- and long-term maternal and fetal impact of metformin in pregnancy compared with insulin. We performed a comprehensive literature search of MEDLINE, EMBASE, BIOSIS, Cochrane Database of Systematic Reviews and ClinicalTrials.gov. Eligible studies were randomized control trials (RCTs) or follow-up of an RCT that: (1) compared metformin with insulin in pregnancy in women with gestational diabetes mellitus or Type 2 diabetes; and (2) reported maternal or fetal outcomes of interest. Two reviewers extracted the data, evaluated study quality and calculated pooled estimates. Sixteen studies (n = 2165 in quantitative analysis) were included. Metformin lowered the risk of neonatal hypoglycaemia [risk ratio (RR) = 0.63; 95% confidence interval (95% CI), 0.45 to 0.87], large for gestational age babies (RR = 0.80; 95% CI, 0.64 to 0.99), pregnancy-induced hypertension (RR = 0.56; 95% CI, 0.37 to 0.85) and total maternal pregnancy weight gain [mean difference (MD) -2.07; 95% CI -2.88 to -1.27]. Metformin did not increase preterm delivery (RR = 1.18; 95% CI 0.67 to 2.07), small for gestational age babies (RR = 1.20; 95% CI, 0.67 to 2.14), perinatal mortality (RR = 0.82; 95% CI, 0.17 to 3.92) or Caesarean section (RR = 0.97; 95% CI, 0.80 to 1.19). Long-term outcome information is limited. Our review found that metformin had no short-term adverse effects on pregnancy, potential benefits in the neonatal period, but limited long-term follow-up information. Prior to routine use, we recommend further follow-up studies of offspring exposed to metformin in utero. © 2016 Diabetes UK.

Galaxy Evolution in Clusters Since z ~ 1

Science.gov (United States)

Aragón-Salamanca, A.

Galaxy clusters provide some of the most extreme environments in which galaxies evolve, making them excellent laboratories to study the age old question of "nature" vs. "nurture" in galaxy evolution. Here I review some of the key observational results obtained during the last decade on the evolution of the morphology, structure, dynamics, star-formation history and stellar populations of cluster galaxies since the time when the Universe was half its present age. Many of the results presented here have been obtained within the ESO Distant Cluster Survey (EDisCS) and Space Telescope A901/02 Galaxy Evolution Survey (STAGES) collaborations.

Effect of BRCA1/2 mutation on short-term and long-term breast cancer survival: a systematic review and meta-analysis.

Science.gov (United States)

Lee, Eun-Ha; Park, Sue K; Park, Boyoung; Kim, Sung-Won; Lee, Min Hyuk; Ahn, Sei Hyun; Son, Byung Ho; Yoo, Keun-Young; Kang, Daehee

2010-07-01

Reports of BRCA genetic mutations and risk of death or recurrence are inconsistent. This study aimed to compare overall and disease-free breast cancer survival rates between BRCA1/2 mutation carriers and non-carriers for short-term and long-term outcomes separately. We searched the PUBMED and EMBASE databases and retrieved 452 articles using keywords that included breast cancer, BRCA mutation, and survival. Seventeen articles were selected for systematic review and among them 11 were included in our meta-analysis. We used the random-effects model to calculate the summary hazard ratio and corresponding 95% confidence interval. BRCA1 mutation carriers had significantly lower short-term and long-term overall survival rates (OSR) relative to non-carriers (HR = 1.92 [95% CI = 1.45-2.53]; 1.33 [1.12-1.58], respectively), while both short-term and long-term OSR of BRCA2 carriers did not differ from non-carriers (HR = 1.30 [95% CI = 0.95-1.76]; 1.12 [95% CI = 0.86-1.45], respectively). For short-term progression-free survival rate (PFSR), BRCA1 mutation carriers had a significantly lower rate than non-carriers (HR = 1.54 [95% CI = 1.12-2.12]), while BRCA2 mutation carriers had a similar PFSR (HR = 1.23 [95% CI = 0.96-1.58]). For long-term PFSRs, we found no significant results. Our results suggest that BRCA1 mutation decreases short-term and long-term OSRs and short-term PFSR, however, BRCA2 mutation does not affect either short-term or long-term survival rate, which is attributed to the different carcinogenic pathways for BRCA1 and BRCA2.

Evolution of senescence in nature: physiological evolution in populations of garter snake with divergent life histories.

Science.gov (United States)

Robert, Kylie A; Bronikowski, Anne M

2010-02-01

Evolutionary theories of aging are linked to life-history theory in that age-specific schedules of reproduction and survival determine the trajectory of age-specific mutation/selection balances across the life span and thus the rate of senescence. This is predicted to manifest at the organismal level in the evolution of energy allocation strategies of investing in somatic maintenance and robust stress responses in less hazardous environments in exchange for energy spent on growth and reproduction. Here we report experiments from long-studied populations of western terrestrial garter snakes (Thamnophis elegans) that reside in low and high extrinsic mortality environments, with evolved long and short life spans, respectively. Laboratory common-environment colonies of these two ecotypes were tested for a suite of physiological traits after control and stressed gestations. In offspring derived from control and corticosterone-treated dams, we measured resting metabolism; mitochondrial oxygen consumption, ATP and free radical production rates; and erythrocyte DNA damage and repair ability. We evaluated whether these aging biomarkers mirrored the evolution of life span and whether they were sensitive to stress. Neonates from the long-lived ecotype (1) were smaller, (2) consumed equal amounts of oxygen when corrected for body mass, (3) had DNA that damaged more readily but repaired more efficiently, and (4) had more efficient mitochondria and more efficient cellular antioxidant defenses than short-lived snakes. Many ecotype differences were enhanced in offspring derived from stress-treated dams, which supports the conclusion that nongenetic maternal effects may further impact the cellular stress defenses of offspring. Our findings reveal that physiological evolution underpins reptilian life histories and sheds light on the connectedness between stress response and aging pathways in wild-dwelling organisms.

Nuclear physics with use of KUR. Reviews of 30 years studies on short-lived nuclei and perspectives for the future

International Nuclear Information System (INIS)

Kawase, Yoichi

1995-01-01

The research works which were carried out over the past 30 years on nuclear structure study have been reviewed with emphasis on the technical developments of experimental apparatus for the studies of very short-lived isotopes produced by the Kyoto University reactor(KUR). In the first chapter, nuclear structure studies of neutron-rich nuclei with use of the on-line irradiation apparatus and the on-line isotope separator(ISOL) for fission products have been described. In the second chapter, applications of nuclear methods to solid state physics by the perturbed angular correlation(PAC) technique have been examined to investigate the local electromagnetic fields in metals and compounds through the hyperfine interactions. Perspectives for the future of related research fields are given aiming at the advanced uses of short-lived radioisotopes. (author)

Molecular evolution and the latitudinal biodiversity gradient.

Science.gov (United States)

Dowle, E J; Morgan-Richards, M; Trewick, S A

2013-06-01

Species density is higher in the tropics (low latitude) than in temperate regions (high latitude) resulting in a latitudinal biodiversity gradient (LBG). The LBG must be generated by differential rates of speciation and/or extinction and/or immigration among regions, but the role of each of these processes is still unclear. Recent studies examining differences in rates of molecular evolution have inferred a direct link between rate of molecular evolution and rate of speciation, and postulated these as important drivers of the LBG. Here we review the molecular genetic evidence and examine the factors that might be responsible for differences in rates of molecular evolution. Critical to this is the directionality of the relationship between speciation rates and rates of molecular evolution.

Evolution of clustered storage

CERN Multimedia

CERN. Geneva; Van de Vyvre, Pierre

2007-01-01

The session actually featured two presentations: * Evolution of clustered storage by Lance Hukill, Quantum Corporation * ALICE DAQ - Usage of a Cluster-File System: Quantum StorNext by Pierre Vande Vyvre, CERN-PH the second one prepared at short notice by Pierre (thanks!) to present how the Quantum technologies are being used in the ALICE experiment. The abstract to Mr Hukill's follows. Clustered Storage is a technology that is driven by business and mission applications. The evolution of Clustered Storage solutions starts first at the alignment between End-users needs and Industry trends: * Push-and-Pull between managing for today versus planning for tomorrow * Breaking down the real business problems to the core applications * Commoditization of clients, servers, and target devices * Interchangeability, Interoperability, Remote Access, Centralized control * Oh, and yes, there is a budget and the "real world" to deal with This presentation will talk through these needs and trends, and then ask the question, ...

Evolution of the hip and pelvis.

Science.gov (United States)

Hogervorst, Tom; Bouma, Heinse W; de Vos, John

2009-08-01

Man's evolution features two unique developments: growing a huge brain and upright gait. Their combination makes the pelvis the most defining skeletal element to read human evolution. Recent revival in joint preserving hip surgery have brought to attention morphological variations of the human hip that appear similar to hips of extant mammals. In man, such variations can produce hip osteoarthrosis through motion. We reviewed the evolution of the hip and pelvis with special interest in morphology that can lead to motion induced osteoarthrosis in man. The combination of giving birth to big brained babies and walking upright has produced marked differences between the sexes in pelvis and hip morphology, each having their characteristic mode of hip impingement and osteoarthrosis.

Gas Evolution in Protoplanetary Disks

NARCIS (Netherlands)

Woitke, Peter; Dent, Bill; Thi, Wing-Fai; Sibthorpe, Bruce; Rice, Ken; Williams, Jonathan; Sicilia-Aguilar, Aurora; Brown, Joanna; Kamp, Inga; Pascucci, Ilaria; Alexander, Richard; Roberge, Aki

2009-01-01

This article summarizes a Splinter Session at the Cool Stars XV conference in St. Andrews with 3 review and 4 contributed talks. The speakers have discussed various approaches to understand the structure and evolution of the gas component in protoplanetary disks. These ranged from observational

Description of the evolution of nonconservative physics

International Nuclear Information System (INIS)

Fronteau, J.

1979-01-01

The objective of this paper is to outline some applications of nonconservative forces in physics, with particular reference to thermodynamics. After some generalities on particle optics, the author points out that the fundamental tool in this field, namely Liouville's theorem, has a much wider bearing than is currently believed, applicable indeed as it is to any dynamical system, conservative or not. The importance of the Jacobian of evolution, which governs the time evolution of the measure in the dynamical space studied, leads the author to justify the introduction of the concept of fine entropy associated to any particle of the system. He shows in fact how this notion allows us to build, on a dissipative basis (purely dissipative to begin with) a thermodynamical theory of evolutive phenomena. He insists on the necessity, for him, to consider the evolutive aspect of phenomena as primordial, with regards to the probabilistic aspect. A short incursion into Quantum Mechanics lays once again insistance on the necessity to study evolution whereever it appears. The author comes finally back to fine Thermodynamics and shows that it admits a relativistic covariant extension, compatible with macroscopic relativistic Thermodynamics. The connection between the physical ideas presented in this work and recent studies on strong nonconservative interactions is indicated in the Foreword

Probing Mechanism of Evolution of Simple Genomes

Science.gov (United States)

Pohorille, Andrew; Ditzler, Mark; Popovic, Milena; Wei, Chenyu

2016-01-01

Our overarching goal is to discover how the structure of the genotypic space of RNA polymers affects their ability to evolve. Specifically, we will address several fundamental questions that, so far, have remained largely unanswered. Was the genotypic space explored globally or only locally? Was the outcome of early evolution predictable or was it, instead, govern by chance? What was the role of neutral mutations in the evolution of increasing complex systems? As the first step, we study the problem in the example of RNA ligases. We obtain the complete, empirical fitness landscapes for short ligases and examine possible evolutionary paths for RNA molecules that are sufficiently long to preclude exhaustive search of the genotypic space.

DNA barcodes for ecology, evolution, and conservation.

Science.gov (United States)

Kress, W John; García-Robledo, Carlos; Uriarte, Maria; Erickson, David L

2015-01-01

The use of DNA barcodes, which are short gene sequences taken from a standardized portion of the genome and used to identify species, is entering a new phase of application as more and more investigations employ these genetic markers to address questions relating to the ecology and evolution of natural systems. The suite of DNA barcode markers now applied to specific taxonomic groups of organisms are proving invaluable for understanding species boundaries, community ecology, functional trait evolution, trophic interactions, and the conservation of biodiversity. The application of next-generation sequencing (NGS) technology will greatly expand the versatility of DNA barcodes across the Tree of Life, habitats, and geographies as new methodologies are explored and developed. Published by Elsevier Ltd.

Prospects for the study of evolution in the deep biosphere.

Science.gov (United States)

Biddle, Jennifer F; Sylvan, Jason B; Brazelton, William J; Tully, Benjamin J; Edwards, Katrina J; Moyer, Craig L; Heidelberg, John F; Nelson, William C

2011-01-01

Since the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times, and easily extractable DNA. Such work has spawned the study of microbial biogeography, with the realization that concepts developed in population genetics may be applicable to microbial genomes (Martiny et al., 2006; Manhes and Velicer, 2011). Microbial biogeography and adaptation has been examined in many different environments. Here we argue that the deep biosphere is a unique environment for the study of evolution and list specific factors that can be considered and where the studies may be performed. This publication is the result of the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI) theme team on Evolution (www.darkenergybiosphere.org).

Ultra-short coherent terahertz radiation from ultra-short dips in electron bunches circulating in a storage ring

International Nuclear Information System (INIS)

Yamamoto, N.; Shimada, M.; Adachi, M.; Zen, H.; Tanikawa, T.; Taira, Y.; Kimura, S.; Hosaka, M.; Takashima, Y.; Takahashi, T.; Katoh, M.

2011-01-01

Terahertz (THz) coherent synchrotron radiation (CSR) is emitted not only from ultra-short electron bunches, but also from electron bunches with micro-structures. Formation of micro-structures at the sub-picosecond scale in electron bunches by a laser slicing technique is experimentally studied through observation of the THz CSR. The THz CSR spectrum was found to depend strongly on the intensity and the pulse width of the laser. The results agreed qualitatively with a numerical simulation. It was suggested that the evolution of the micro-structure during CSR emission is important under some experimental conditions.

Following the Social Media: Aspect Evolution of Online Discussion

Science.gov (United States)

Tang, Xuning; Yang, Christopher C.

Due to the advance of Internet and Web 2.0 technologies, it is easy to extract thousands of threads about a topic of interest from an online forum but it is nontrivial to capture the blueprint of different aspects (i.e., subtopic, or facet) associated with the topic. To better understand and analyze a forum discussion given topic, it is important to uncover the evolution relationships (temporal dependencies) between different topic aspects (i.e. how the discussion topic is evolving). Traditional Topic Detection and Tracking (TDT) techniques usually organize topics as a flat structure but it does not present the evolution relationships between topic aspects. In addition, the properties of short and sparse messages make the content-based TDT techniques difficult to perform well in identifying evolution relationships. The contributions in this paper are two-folded. We formally define a topic aspect evolution graph modeling framework and propose to utilize social network information, content similarity and temporal proximity to model evolution relationships between topic aspects. The experimental results showed that, by incorporating social network information, our technique significantly outperformed content-based technique in the task of extracting evolution relationships between topic aspects.

Peking Man to Socialist Man: The Teaching of Human Evolution in China.

Science.gov (United States)

Swetz, Frank J.

1986-01-01

Examines the content and methodology of the teaching of human evolution in the schools of the People's Republic of China. Reviews the aims and goals of science teaching and their effects on the teaching of evolution. Emphasizes evolution, compatibility with China's political doctrines, and includes illustrations of instructional materials. (ML)

Short notes and reviews Insect history

NARCIS (Netherlands)

Schram, Frederick R.

2003-01-01

Review of: History of Insects, edited by A. P. Rasnitsyn and D. L. J. Quicke. Kluwer Academic Publ., Dordrecht, Netherlands, 2002, 517 pp., ISBN 14 0200 026 X In the winter of 1977, I visited the Paleontological Institute of the Academy of Sciences in Moscow. I wanted to study the type specimens of

Radiopharmaceuticals and other compounds labelled with short-lived radionuclides

CERN Document Server

Welch, Michael J

2013-01-01

Radiopharmaceuticals and Other Compounds Labelled with Short-Lived Radionuclides covers through both review and contributed articles the potential applications and developments in labeling with short-lived radionuclides whose use is restricted to institutions with accelerators. The book discusses the current and potential use of generator-produced radionuclides as well as other short-lived radionuclides, and the problems of quality control of such labeled compounds. The book is useful to nuclear medicine physicians.

Short interspersed elements (SINEs) in plants: origin, classification, and use as phylogenetic markers.

Science.gov (United States)

Deragon, Jean-Marc; Zhang, Xiaoyu

2006-12-01

Short interspersed elements (SINEs) are a class of dispersed mobile sequences that use RNA as an intermediate in an amplification process called retroposition. The presence-absence of a SINE at a given locus has been used as a meaningful classification criterion to evaluate phylogenetic relations among species. We review here recent developments in the characterisation of plant SINEs and their use as molecular makers to retrace phylogenetic relations among wild and cultivated Oryza and Brassica species. In Brassicaceae, further use of SINE markers is limited by our partial knowledge of endogenous SINE families (their origin and evolution histories) and by the absence of a clear classification. To solve this problem, phylogenetic relations among all known Brassicaceae SINEs were analyzed and a new classification, grouping SINEs in 15 different families, is proposed. The relative age and size of each Brassicaceae SINE family was evaluated and new phylogenetically supported subfamilies were described. We also present evidence suggesting that new potentially active SINEs recently emerged in Brassica oleracea from the shuffling of preexisting SINE portions. Finally, the comparative evolution history of SINE families present in Arabidopsis thaliana and Brassica oleracea revealed that SINEs were in general more active in the Brassica lineage. The importance of these new data for the use of Brassicaceae SINEs as molecular markers in future applications is discussed.

The organization and evolution of the Responder satellite in species of the Drosophila melanogaster group: dynamic evolution of a target of meiotic drive.

Science.gov (United States)

Larracuente, Amanda M

2014-11-25

Satellite DNA can make up a substantial fraction of eukaryotic genomes and has roles in genome structure and chromosome segregation. The rapid evolution of satellite DNA can contribute to genomic instability and genetic incompatibilities between species. Despite its ubiquity and its contribution to genome evolution, we currently know little about the dynamics of satellite DNA evolution. The Responder (Rsp) satellite DNA family is found in the pericentric heterochromatin of chromosome 2 of Drosophila melanogaster. Rsp is well-known for being the target of Segregation Distorter (SD)- an autosomal meiotic drive system in D. melanogaster. I present an evolutionary genetic analysis of the Rsp family of repeats in D. melanogaster and its closely-related species in the melanogaster group (D. simulans, D. sechellia, D. mauritiana, D. erecta, and D. yakuba) using a combination of available BAC sequences, whole genome shotgun Sanger reads, Illumina short read deep sequencing, and fluorescence in situ hybridization. I show that Rsp repeats have euchromatic locations throughout the D. melanogaster genome, that Rsp arrays show evidence for concerted evolution, and that Rsp repeats exist outside of D. melanogaster, in the melanogaster group. The repeats in these species are considerably diverged at the sequence level compared to D. melanogaster, and have a strikingly different genomic distribution, even between closely-related sister taxa. The genomic organization of the Rsp repeat in the D. melanogaster genome is complex-it exists of large blocks of tandem repeats in the heterochromatin and small blocks of tandem repeats in the euchromatin. My discovery of heterochromatic Rsp-like sequences outside of D. melanogaster suggests that SD evolved after its target satellite and that the evolution of the Rsp satellite family is highly dynamic over a short evolutionary time scale (<240,000 years).

Short Tools to Assess Young Children's Dietary Intake: A Systematic Review Focusing on Application to Dietary Index Research

Directory of Open Access Journals (Sweden)

Lucinda K. Bell

2013-01-01

Full Text Available Dietary indices evaluate diet quality, usually based on current dietary guidelines. Indices can therefore contribute to our understanding of early-life obesity-risk dietary behaviours. Yet indices are commonly applied to dietary data collected by onerous methods (e.g., recalls or records. Short dietary assessment instruments are an attractive alternative to collect data from which to derive an index score. A systematic review of studies published before April 2013 was conducted to identify short (≤50 items tools that measure whole-of-diet intake of young children (birth-five years and are applicable to dietary indices, in particular screening obesogenic dietary behaviours. The search identified 3686 papers of which 16, reporting on 15 tools (n=7, infants and toddlers birth-24 months; n=8, preschoolers 2–5 years, met the inclusion criteria. Most tools were food frequency questionnaires (n=14, with one innovative dietary questionnaire identified. Seven were tested for validity or reliability, and one was tested for both. Six tools (n=2, infants and toddlers; n=4, preschoolers are applicable for use with current dietary indices, five of which screen obesogenic dietary behaviours. Given the limited number of brief, valid and reliable dietary assessment tools for young children to which an index can be applied, future short tool development is warranted, particularly for screening obesogenic dietary behaviours.

Planets a very short introduction

CERN Document Server

Rothery, David A

2010-01-01

Planets: A Very Short Introduction demonstrates the excitement, uncertainties, and challenges faced by planetary scientists, and provides an overview of our Solar System and its origins, nature, and evolution. Terrestrial planets, giant planets, dwarf planets and various other objects such as satellites (moons), asteroids, trans-Neptunian objects, and exoplanets are discussed. Our knowledge about planets has advanced over the centuries, and has expanded at a rapidly growing rate in recent years. Controversial issues are outlined, such as What qualifies as a planet? What conditions are required for a planetary body to be potentially inhabited by life? Why does Pluto no longer have planet status? And Is there life on other planets?

Radiation and the evolution of life

International Nuclear Information System (INIS)

Gentner, N.E.; Myers, D.K.

1980-08-01

A general review is presented of the nature of various forms of radiation; radiant energy which reaches the earth from the sun; the role of this energy in prebiotic chemical evolution; current ideas on the origin of life; the dependence of living organisms upon radiant energy; the mechanisms responsible for the evolution of life, from the viewpoint of modern genetics and molecular biology; the biological consequences of alterations in the genetic material; and the role of ionizing radiation in production of genetic changes and in evolution. In the final analysis, the biosynthetic processes of life are driven by radiant energy from the sun. This overview is necessarily focussed on the infrared, visible and ultraviolet regions of the solar output spectrum since these particular radiations are responsible for most of the radiant energy that reaches the earth's surface. Ionizing radiation appears to have played at best a minor role in biological evolution. Small increments in the amounts of ionizing radiation are therefore unlikely to have a significant effect on life or its evolution. (auth)

Impact of growth hormone therapy on adult height of children with idiopathic short stature: systematic review.

Science.gov (United States)

Deodati, Annalisa; Cianfarani, Stefano

2011-03-11

To systematically determine the impact of growth hormone therapy on adult height of children with idiopathic short stature. Systematic review. Cochrane Central Register of Controlled Trials, Medline, and the bibliographic references from retrieved articles of randomised and non-randomised controlled trials from 1985 to April 2010. Height in adulthood (standard deviation score) and overall gain in height (SD score) from baseline measurement in childhood. Randomised and non-randomised controlled trials with height measurements for adults. Inclusion criteria were initial short stature (defined as height >2 SD score below the mean), peak growth hormone responses >10 μg/L, prepubertal stage, no previous growth hormone therapy, and no comorbid conditions that would impair growth. Adult height was considered achieved when growth rate was growth hormone treated children exceeded that of the controls by 0.65 SD score (about 4 cm). The mean height gain in treated children was 1.2 SD score compared with 0.34 SD score in untreated children. A slight difference of about 1.2 cm in adult height was observed between the two growth hormone dose regimens. In the seven non-randomised controlled trials the adult height of the growth hormone treated group exceeded that of the controls by 0.45 SD score (about 3 cm). Growth hormone therapy in children with idiopathic short stature seems to be effective in partially reducing the deficit in height as adults, although the magnitude of effectiveness is on average less than that achieved in other conditions for which growth hormone is licensed. The individual response to therapy is highly variable, and additional studies are needed to identify the responders.

On trailing vortices: A short review

International Nuclear Information System (INIS)

Jacquin, Laurent

2005-01-01

This paper reviews some mechanisms involved in the dynamics of vortices in fluid flows. The topic is first introduced by pointing out its importance in aerodynamics. Several basic notions useful to appraise experimental observations are then surveyed, namely: centrifugal instabilities, inertial waves, cooperative instabilities, vortex merger, vortex breakdown and turbulence in vortices. Each topic is illustrated with experimental or numerical results

Network analysis of metabolic enzyme evolution in Escherichia coli

Directory of Open Access Journals (Sweden)

Kraulis Per

2004-02-01

Full Text Available Abstract Background The two most common models for the evolution of metabolism are the patchwork evolution model, where enzymes are thought to diverge from broad to narrow substrate specificity, and the retrograde evolution model, according to which enzymes evolve in response to substrate depletion. Analysis of the distribution of homologous enzyme pairs in the metabolic network can shed light on the respective importance of the two models. We here investigate the evolution of the metabolism in E. coli viewed as a single network using EcoCyc. Results Sequence comparison between all enzyme pairs was performed and the minimal path length (MPL between all enzyme pairs was determined. We find a strong over-representation of homologous enzymes at MPL 1. We show that the functionally similar and functionally undetermined enzyme pairs are responsible for most of the over-representation of homologous enzyme pairs at MPL 1. Conclusions The retrograde evolution model predicts that homologous enzymes pairs are at short metabolic distances from each other. In general agreement with previous studies we find that homologous enzymes occur close to each other in the network more often than expected by chance, which lends some support to the retrograde evolution model. However, we show that the homologous enzyme pairs which may have evolved through retrograde evolution, namely the pairs that are functionally dissimilar, show a weaker over-representation at MPL 1 than the functionally similar enzyme pairs. Our study indicates that, while the retrograde evolution model may have played a small part, the patchwork evolution model is the predominant process of metabolic enzyme evolution.

Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials

Directory of Open Access Journals (Sweden)

Bogen Bård

2007-06-01

Full Text Available Abstract Background Treatment efficacy of physical agents in osteoarthritis of the knee (OAK pain has been largely unknown, and this systematic review was aimed at assessing their short-term efficacies for pain relief. Methods Systematic review with meta-analysis of efficacy within 1–4 weeks and at follow up at 1–12 weeks after the end of treament. Results 36 randomised placebo-controlled trials (RCTs were identified with 2434 patients where 1391 patients received active treatment. 33 trials satisfied three or more out of five methodological criteria (Jadad scale. The patient sample had a mean age of 65.1 years and mean baseline pain of 62.9 mm on a 100 mm visual analogue scale (VAS. Within 4 weeks of the commencement of treatment manual acupuncture, static magnets and ultrasound therapies did not offer statistically significant short-term pain relief over placebo. Pulsed electromagnetic fields offered a small reduction in pain of 6.9 mm [95% CI: 2.2 to 11.6] (n = 487. Transcutaneous electrical nerve stimulation (TENS, including interferential currents, electro-acupuncture (EA and low level laser therapy (LLLT offered clinically relevant pain relieving effects of 18.8 mm [95% CI: 9.6 to 28.1] (n = 414, 21.9 mm [95% CI: 17.3 to 26.5] (n = 73 and 17.7 mm [95% CI: 8.1 to 27.3] (n = 343 on VAS respectively versus placebo control. In a subgroup analysis of trials with assumed optimal doses, short-term efficacy increased to 22.2 mm [95% CI: 18.1 to 26.3] for TENS, and 24.2 mm [95% CI: 17.3 to 31.3] for LLLT on VAS. Follow-up data up to 12 weeks were sparse, but positive effects seemed to persist for at least 4 weeks after the course of LLLT, EA and TENS treatment was stopped. Conclusion TENS, EA and LLLT administered with optimal doses in an intensive 2–4 week treatment regimen, seem to offer clinically relevant short-term pain relief for OAK.

The evolution of whole-body imaging.

LENUS (Irish Health Repository)

Moran, Deirdre E

2012-02-01

This article reviews the evolution of whole-body imaging, discussing the history and development of radiography, nuclear medicine, computed tomography (CT), positron emission tomography (PET), combined PET-CT, and magnetic resonance imaging. The obstacles hindering progress toward whole-body imaging using each of these modalities, and the technical advances that were developed to overcome them, are reviewed. The effectiveness and the limitations of whole-body imaging with each of these techniques are also briefly discussed.

Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

Science.gov (United States)

Adabi, Saba; Turani, Zahra; Fatemizadeh, Emad; Clayton, Anne; Nasiriavanaki, Mohammadreza

2017-01-01

Optical coherence tomography (OCT) delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts. PMID:28638245

Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review

Directory of Open Access Journals (Sweden)

Saba Adabi

2017-06-01

Full Text Available Optical coherence tomography (OCT delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts.

Organotins in Neuronal Damage, Brain Function, and Behavior: A Short Review

Directory of Open Access Journals (Sweden)

Igor Ferraz da Silva

2018-01-01

Full Text Available The consequences of exposure to environmental contaminants have shown significant effects on brain function and behavior in different experimental models. The endocrine-disrupting chemicals (EDC present various classes of pollutants with potential neurotoxic actions, such as organotins (OTs. OTs have received special attention due to their toxic effects on the central nervous system, leading to abnormal mammalian neuroendocrine axis function. OTs are organometallic pollutants with a tin atom bound to one or more carbon atoms. OT exposure may occur through the food chain and/or contaminated water, since they have multiple applications in industry and agriculture. In addition, OTs have been used with few legal restrictions in the last decades, despite being highly toxic. In addition to their action as EDC, OTs can also cross the blood–brain barrier and show relevant neurotoxic effects, as observed in several animal model studies specifically involving the development of neurodegenerative processes, neuroinflammation, and oxidative stress. Thus, the aim of this short review is to summarize the toxic effects of the most common OT compounds, such as trimethyltin, tributyltin, triethyltin, and triphenyltin, on the brain with a focus on neuronal damage as a result of oxidative stress and neuroinflammation. We also aim to present evidence for the disruption of behavioral functions, neurotransmitters, and neuroendocrine pathways caused by OTs.

The Evolution of Learning Mechanisms.

Science.gov (United States)

Garcia, John; Garcia y Robertson, Rodrigo

This paper introduces seven principles of learning, enduring over the last five centuries of psychological thought, to discuss the evolution of the "Biophyche" (the brain in action) in the development of humans and other large organisms. It describes the conditioning theories of Darwin, Pavlov, and Thorndike and critically reviews the…

Evolution of subsurface nanocavities in copper under argon bombardment and annealing

NARCIS (Netherlands)

Kulikov, D.V.; Kurnosikov, O.; Kharlamov, V.S.; Trushin, Yu.V.

2013-01-01

The experimental and theoretical studies of evolution of nanocavities in argon-irradiated copper under annealing are presented. The subsurface argon-filled nanocavities are formed during a short annealing at a temperature around 1000 K by migration and interaction of complexes of the simplest

Validation of a short-term shoreline evolution model and coastal risk management implications. The case of the NW Portuguese coast (Ovar-Marinha Grande)

Science.gov (United States)

Cenci, Luca; Giuseppina Persichillo, Maria; Disperati, Leonardo; Oliveira, Eduardo R.; de Fátima Lopes Alves, Maria; Boni, Giorgio; Pulvirenti, Luca; Phillips, Mike

2015-04-01

Coastal zones are fragile and dynamic environments where environmental, economic and social aspects are interconnected. While these areas are often highly urbanised, they are especially vulnerable to natural hazards (e.g. storms, floods, erosion, storm surges). Hence, high risk affects people and goods in several coastal zones throughout the world. The recent storms that hit the European coasts (Hercules, Christian and Stephanie, among others) showed the high vulnerability of these territories. Integrated Coastal Management (ICM) deals with the sustainable development of coastal zones by taking into account the different aspects that affect them, including risks adaptation and mitigation. Accurate mapping of shoreline position through time and models to predict shoreline evolution play a fundamental role for coastal zone risk management. In this context, spaceborne remote sensing is fundamental because it provides synoptic and multitemporal information that allow the extraction of shorelines' proxies. These are stable coastal features (e.g. the vegetation lines, the foredune toe, etc.) that can be mapped instead of the proper shoreline, which is an extremely dynamic boundary. The use of different proxies may provide different evolutionary patterns for the same study area; therefore it is important to assess which is the most suitable, given the environmental characteristics of a specific area. In Portugal, the coastal stretch between Ovar and Marinha Grande is one of the greatest national challenges in terms of integrated management of resources and risks. This area is characterised by intense erosive processes that largely exceed the shoreline's retreat predictions made in the first Coastal Zone Management Plan, developed in 2000. The aim of this work was to assess the accuracy of a new model of shoreline evolution implemented in 2013 in order to check its robustness for short-term predictions. The method exploited the potentialities of the Landsat archive

Short Review: Mitigation of Current Environmental Concerns from Methanol Synthesis

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Andrew Young

2013-06-01

Full Text Available Methanol has become a widely used and globally distributed product. Methanol is very important due to the current depletion of fossil fuels. Industrially, methanol produced from the catalytic reaction of synthetic gas composed of hydrogen, carbon monoxide, and carbon dioxide. Methanol production has brought great attention due to carbon dioxide as the main source of greenhouse gas emissions. Combined of reducing CO2 emissions and supplying an alternative fuel source has created the idea of a carbon neutral cycle called “the methanol economy”. The best catalyst for the methanol economy would show a high CO2 conversion and high selectivity for methanol production. This paper investigates research focused on catalyst development for efficient methanol synthesis from hydrogenation of carbon dioxide through added various supports and additives such as silica, zirconium, and palladium. Catalysts that displayed the highest activity included a zirconia and silicon-titanium oxide promoted Cu/Zn/Al2O3 catalyst. Alternative method of catalyst preparation, include the oxalate-gel, solid-state reaction, co-precipitation and combustion method also investigated.  © 2013 BCREC UNDIP. All rights reservedReceived: 10th October 2012; Revised: 7th February 2012; Accepted: 10th February 2013[How to Cite: Young, A., Lesmana, D., Dai, D.J., Wu, H.S. (2013. Short Review: Mitigation of Current En-vironmental Concerns from Methanol Synthesis. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 1-13. (doi:10.9767/bcrec.8.1.4055.1-13][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4055.1-13] | View in  |

Short-term plasticity as a neural mechanism supporting memory and attentional functions

OpenAIRE

Jääskeläinen, Iiro P.; Ahveninen, Jyrki; Andermann, Mark L.; Belliveau, John W.; Raij, Tommi; Sams, Mikko

2011-01-01

Based on behavioral studies, several relatively distinct perceptual and cognitive functions have been defined in cognitive psychology such as sensory memory, short-term memory, and selective attention. Here, we review evidence suggesting that some of these functions may be supported by shared underlying neuronal mechanisms. Specifically, we present, based on an integrative review of the literature, a hypothetical model wherein short-term plasticity, in the form of transient center-excitatory ...

Numerical analysis of short-pulse laser interactions with thin metal film

Directory of Open Access Journals (Sweden)

E. Majchrzak

2010-10-01

Full Text Available Thin metal film subjected to a short-pulse laser heating is considered. The hyperbolic two-temperature model describing the temporal andspatial evolution of the lattice and electrons temperatures is discussed. At the stage of numerical computations the finite difference method is used. In the final part of the paper the examples of computations are shown.

Endocasts-the direct evidence and recent advances in the study of human brain evolution

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Brain evolution is one of the most important aspects of human evolution, usually studied through endocasts. Analysis of fossil hominid endocasts allows inferences on functional anatomy, physiology, and phylogeny. In this paper, we describe the general features of endocast studies and review some of the major topics in paleoneurology. These are: absolute and relative brain size evolution; brain shape variation; brain asymmetry and lateralization; middle meningeal vessels and venous sinuses; application of computed tomography and virtual imaging; the history of Chinese brain endocast studies. In particular, this review emphasizes endocast studies on Chinese hominin fossils.

Book Review: Evolution's Chimera: Bats and the Marvel of ...

African Journals Online (AJOL)

Abstract. Book Title: Evolution's Chimera: Bats and the Marvel of Evolutionary Adaptation. Book Author: David Jacobs. 2016, University of Cape Town Press, Juta and Company (Pty) Ltd, PO Box 14373, Lansdowne 7779, Cape Town, South Africa Softcover, 204 pages. ISBN 978-1-77582-212-7. Price R299 ...

Hydrodynamics experiments with soap films and soap bubbles: A short review of recent experiments

Science.gov (United States)

Kellay, H.

2017-11-01

In this short review, I focus on recent experiments that benefit from the advantages offered by the two-dimensionality of the flow in suspended thin liquid films to reconsider hydrodynamics problems which have resisted a full understanding. The first problem discussed here concerns friction drag in channel flows. The use of turbulent channel flows, using thin liquid films, allows measurements of friction drag as well as mean velocity profiles for flows with different spectral exponents. Is there a link between the spectral properties of the turbulence and the mean velocity profiles or the frictional drag? This is the first question considered. The second issue examined considers the long time dynamics of large scale vortices. These are obtained in half bubbles rendered "turbulent" through thermal convection. These vortices, which live in a quasi two-dimensional environment, have a long time dynamics where their vorticity goes through what seems to be a well-defined cycle with generic features.

Prospects for the study of evolution in the deep biosphere

Directory of Open Access Journals (Sweden)

Jennifer F Biddle

2012-01-01

Full Text Available Since the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times and easily extractable DNA. Such work has spawned the study of microbial biogeography, with the realization that concepts developed in population genetics may be applicable to microbial genomes (Manhes et al. 2011, Martiny et al. 2006. Microbial biogeography and adaptation has been examined in many different environments. Here we argue that the deep biosphere is a unique environment for the study of evolution and list specific factors that can be considered and where the studies may be performed. This publication is the result of the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI theme team on Evolution (www.darkenergybiosphere.org.

Prospects for the Study of Evolution in the Deep Biosphere

Science.gov (United States)

Biddle, Jennifer F.; Sylvan, Jason B.; Brazelton, William J.; Tully, Benjamin J.; Edwards, Katrina J.; Moyer, Craig L.; Heidelberg, John F.; Nelson, William C.

2012-01-01

Since the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times, and easily extractable DNA. Such work has spawned the study of microbial biogeography, with the realization that concepts developed in population genetics may be applicable to microbial genomes (Martiny et al., 2006; Manhes and Velicer, 2011). Microbial biogeography and adaptation has been examined in many different environments. Here we argue that the deep biosphere is a unique environment for the study of evolution and list specific factors that can be considered and where the studies may be performed. This publication is the result of the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI) theme team on Evolution (www.darkenergybiosphere.org). PMID:22319515

The evolution of the Cepheid stars

International Nuclear Information System (INIS)

Chiosi, C.

1990-01-01

The evolution of intermediate and high mass stars is reviewed focusing on the interpretation of Pop I Cepheids. First, a summary is given of the classical results of stellar evolution theory for the main evolutionary phases (main sequence and core He-burning) all over the HR diagram, putting into evidence the various points of disagreement with current observational data. Second, models incorporating the effect of convective overshoot, are reviewed, and studies are presented on the rich, young clusters in the Large Magellanic Cloud, in which the models are compared with the observational data. Arguments are given to favor the adoption of models with convective overshoot instead of the classical ones. Third, new results are presented for pulsational models of the Cepheid stars, and the shape of the instability strip in the HR diagram, the number frequency-period distribution, and the mass discrepancy are discussed. 81 refs

Galaxy evolution in clusters since z=1

Science.gov (United States)

Aragón-Salamanca, A.

2011-11-01

It is now 30 years since Alan Dressler published his seminal paper onthe morphology-density relation. Although there is still much to learnon the effect of the environment on galaxy evolution, extensive progress has been made since then both observationally and theoretically.Galaxy clusters provide some of the most extreme environments in which galaxies evolve, making them excellent laboratories to study the age old question of "nature'' vs. "nurture'' in galaxy evolution. Here I review some of the key observational results obtained during the last decade on the evolution of the morphology, structure, dynamics, star-formation history and stellar populations of cluster galaxies since the time when the universe was half its present age.Many of the results presented here have been obtainedwithin the ESO Distant Cluster Survey (EDisCS) and Space Telescope A901/02 Galaxy Evolution Survey (STAGES) collaborations.

Big Bang Tumor Growth and Clonal Evolution.

Science.gov (United States)

Sun, Ruping; Hu, Zheng; Curtis, Christina

2018-05-01

The advent and application of next-generation sequencing (NGS) technologies to tumor genomes has reinvigorated efforts to understand clonal evolution. Although tumor progression has traditionally been viewed as a gradual stepwise process, recent studies suggest that evolutionary rates in tumors can be variable with periods of punctuated mutational bursts and relative stasis. For example, Big Bang dynamics have been reported, wherein after transformation, growth occurs in the absence of stringent selection, consistent with effectively neutral evolution. Although first noted in colorectal tumors, effective neutrality may be relatively common. Additionally, punctuated evolution resulting from mutational bursts and cataclysmic genomic alterations have been described. In this review, we contrast these findings with the conventional gradualist view of clonal evolution and describe potential clinical and therapeutic implications of different evolutionary modes and tempos. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Technical note. SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC. Contribution to the Initial Review Phase

Energy Technology Data Exchange (ETDEWEB)

Benbow, Steven; Metcalfe, Richard; Watson, Claire; Bond, Alex [Quintessa Ltd, Henley on Thames (United Kingdom)

2012-11-01

This review has focussed mainly on the modelling of the Engineered Barrier System (EBS) evolution, which includes coupled thermal, hydraulic, mechanical and chemical (THMC) processes. Additionally, the role of the EBS in the wider safety case was reviewed, including its treatment in scenarios and its representation in conceptual models since this provided the motivation for the modelling work that was undertaken by SKB. The scope of the work described here was to: 1. Review relevant documents concerning SKB's modelling; and 2. Check one particular modelling area that was judged to be important, based on this review, with a limited set of independent modelling/calculations. The review covers the early resaturation and swelling / homogenisation of the buffer; the longer-term chemical evolution of the buffer and backfill, corrosion of the copper canister and the chemical and hydrogeological boundary conditions provided by the surrounding host rock. The reviewers consider that SKB's modelling of engineered barrier performance generally supports their conclusion that the barriers will perform as required. However, there remain issues that are not addressed and uncertainties that are not explored adequately by SKB's modelling. The thermo-hydro-mechanical modelling of buffer resaturation that is performed by SKB is based on demonstrating a fit to measurements from the in-situ Canister Retrieval Test (CRT) experiment. The modelling reproduces some of the experimental observations very well, but some key experimental measurements are not considered. In particular, investigation of the fit to the measured rates of water inflow, which are a critical factor controlling the rate at which the buffer will resaturate, is not given, Furthermore, the water supply boundary conditions imposed on the CRT are not considered to be representative of those that might be expected in repository conditions. From the information that it is presented it is therefore not possible

[The evolution of plant life span: facts and hypotheses].

Science.gov (United States)

2006-01-01

There are two different views on the evolution of life forms in Cormophyta: from woody plants to herbaceous ones or in opposite direction - from herbs to trees. In accordance with these views it is supposed that life span in plants changed in the course of evolution from many years (perennials) to few years (annuals, biennials), or went in reverse - from few years to many years. The author discusses the problems of senescence and longevity in Cormophyta in the context of various hypotheses of ageing (programmed death theory, mutation accumulation, antagonistic pleiotropy, disposable soma, genes of ageing, genes of longevity). Special attention is given to bio-morphological aspects of longevity and cases of non-ageing plants ("negative senescence", "potential immortality"). It is proposed to distinguish seven models of simple ontogenesis in Cormophyta that can exemplify the diversity of mechanisms of ageing and longevity. The evolution of life span in plants is considered as an indirect result of natural selection of other characteristics of organisms or as a consequence of fixation of modifications (episelectional evolution). It seems that short life span could emerge several times during evolution of one group of plants, thus favoring its adaptive radiation.

The evolution of the elements

International Nuclear Information System (INIS)

Williams, P.M.

1978-01-01

It is believed that only the lightest elements, hydrogen and helium, were created during the 'Big Bang' origin of the Universe and that all heavier elements were synthesized by nuclear reactions in stars, the interstellar medium and possibly in 'little bangs' in the nuclei of galaxies. The composition of the interstellar medium has evolved through enrichment by processed material shed by evolving stars and the composition of the Solar System reflects that of the interstellar medium at the time of its formation. Differentiation processes during the evolution of the Solar System and individual planets account for the different compositions of the Sun and the planets. The measurement of the abundance distribution of the elements has become a very powerful tool in the elucidation of the evolution of the Solar System, stars and the Galaxy. This review attempts to trace the formation of the elements in stars and their subsequent evolution. (author)

Origin, structure and evolution of galaxies

International Nuclear Information System (INIS)

Zhi, F.L.

1988-01-01

Recent developments of the origin, structure and evolution of galaxies have been reviewed. The contents of this book are: Inflationary Universe; Cosmic String; Active Galaxies; Intergalactic Medium; Waves in Disk Galaxies; Dark Matter; Gas Dynamics in Disk Galaxies; Equilibrium and Stability of Spiral Galaxies

INFLUENCE OF TRADITIONAL DANCE TRAINING PROGRAMS ON DYNAMIC BALANCE OF PEOPLE WITH INTELLECTUAL DISABILITY: A SHORT REVIEW

Directory of Open Access Journals (Sweden)

K. Tsimaras Vasileios

2015-05-01

Full Text Available Traditional dance is gaining popularity as an intervention choice for improving poor balance ability of people with intellectual disability (ID. Balance improvement for individuals with ID through dance provides opportunities for participation in sport activities and promotes independent living. This short review provides in brief research evidence of dynamic balance improvement as measured by means of a balance deck in duration of 30, 45, and 60 sec intervals, highlighting the need to incorporate traditional dance programs in Physical Education (PE lessons applied on participants with ID. Overall, traditional dances provide emotional and cognitive interaction that has a direct positive effect on quality of life and successful motor performance of individuals with ID.

INFLUENCE OF TRADITIONAL DANCE TRAINING PROGRAMS ON DYNAMIC BALANCE OF PEOPLE WITH INTELLECTUAL DISABILITY: A SHORT REVIEW

Directory of Open Access Journals (Sweden)

Vasileios K. Tsimaras

2015-04-01

Full Text Available Traditional dance is gaining popularity as an intervention choice for improving poor balance ability of people with intellectual disability (ID. Balance improvement for individuals with ID through dance provides opportunities for participation in sport activities and promotes independent living. This short review provides in brief research evidence of dynamic balance improvement as measured by means of a balance deck in duration of 30, 45, and 60 sec intervals, highlighting the need to incorporate traditional dance programs in Physical Education (PE lessons applied on participants with ID. Overall, traditional dances provide emotional and cognitive interaction that has a direct positive effect on quality of life and successful motor performance of individuals with ID.

Evolution before genes

Directory of Open Access Journals (Sweden)

Vasas Vera

2012-01-01

Full Text Available Abstract Background Our current understanding of evolution is so tightly linked to template-dependent replication of DNA and RNA molecules that the old idea from Oparin of a self-reproducing 'garbage bag' ('coacervate' of chemicals that predated fully-fledged cell-like entities seems to be farfetched to most scientists today. However, this is exactly the kind of scheme we propose for how Darwinian evolution could have occurred prior to template replication. Results We cannot confirm previous claims that autocatalytic sets of organic polymer molecules could undergo evolution in any interesting sense by themselves. While we and others have previously imagined inhibition would result in selectability, we found that it produced multiple attractors in an autocatalytic set that cannot be selected for. Instead, we discovered that if general conditions are satisfied, the accumulation of adaptations in chemical reaction networks can occur. These conditions are the existence of rare reactions producing viable cores (analogous to a genotype, that sustains a molecular periphery (analogous to a phenotype. Conclusions We conclude that only when a chemical reaction network consists of many such viable cores, can it be evolvable. When many cores are enclosed in a compartment there is competition between cores within the same compartment, and when there are many compartments, there is between-compartment competition due to the phenotypic effects of cores and their periphery at the compartment level. Acquisition of cores by rare chemical events, and loss of cores at division, allows macromutation, limited heredity and selectability, thus explaining how a poor man's natural selection could have operated prior to genetic templates. This is the only demonstration to date of a mechanism by which pre-template accumulation of adaptation could occur. Reviewers This article was reviewed by William Martin and Eugene Koonin.

Does selection for short sleep duration explain human vulnerability to Alzheimer's disease?

Science.gov (United States)

Nesse, Randolph M; Finch, Caleb E; Nunn, Charles L

2017-01-16

Compared with other primates, humans sleep less and have a much higher prevalence of Alzheimer 's disease (AD) pathology. This article reviews evidence relevant to the hypothesis that natural selection for shorter sleep time in humans has compromised the efficacy of physiological mechanisms that protect against AD during sleep. In particular, the glymphatic system drains interstitial fluid from the brain, removing extra-cellular amyloid beta (eAβ) twice as fast during sleep. In addition, melatonin - a peptide hormone that increases markedly during sleep - is an effective antioxidant that inhibits the polymerization of soluble eAβ into insoluble amyloid fibrils that are associated with AD. Sleep deprivation increases plaque formation and AD, which itself disrupts sleep, potentially creating a positive feedback cycle. These and other physiological benefits of sleep may be compromised by short sleep durations. Our hypothesis highlights possible long-term side effects of medications that reduce sleep, and may lead to potential new strategies for preventing and treating AD. © The Author(s) 2017. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

Evolution of extreme temperature events in short term climate projection for Iberian Peninsula.

Science.gov (United States)

Rodriguez, Alfredo; Tarquis, Ana M.; Sanchez, Enrique; Dosio, Alessandro; Ruiz-Ramos, Margarita

2014-05-01

Extreme events of maximum and minimum temperatures are a main hazard for agricultural production in Iberian Peninsula. For this purpose, in this study we analyze projections of their evolution that could be valid for the next decade, represented in this study by the 30-year period 2004-2034 (target period). For this purpose two kinds of data were used in this study: 1) observations from the station network of AEMET (Spanish National Meteorological Agency) for five Spanish locations, and 2) simulated data at a resolution of 50 ×50 km horizontal grid derived from the outputs of twelve Regional Climate Models (RCMs) taken from project ENSEMBLES (van der Linden and Mitchell, 2009), with a bias correction (Dosio and Paruolo, 2011; Dosio et al., 2012) regarding the observational dataset Spain02 (Herrera et al., 2012). To validate the simulated climate, the available period of observations was compared to a baseline period (1964-1994) of simulated climate for all locations. Then, to analyze the changes for the present/very next future, probability of extreme temperature events for 2004-2034 were compared to that of the baseline period. Although only minor changes are expected, small variations in variability may have a significant impact in crop performance. The objective of the work is to evaluate the utility of these short term projections for potential users, as for instance insurance companies. References Dosio A. and Paruolo P., 2011. Bias correction of the ENSEMBLES high-resolution climate change projections for use by impact models: Evaluation on the present climate. Journal of Geophysical Research, VOL. 116,D16106, doi:10.1029/2011JD015934 Dosio A., Paruolo P. and Rojas R., 2012. Bias correction of the ENSEMBLES high resolution climate change projections for use by impact models: Analysis of the climate change signal. Journal of Geophysical Research,Volume 117, D17, doi: 0.1029/2012JD017968 Herrera et. al. (2012) Development and Analysis of a 50 year high

Time evolution of the quark-gluon plasma

International Nuclear Information System (INIS)

Cooper, F.; New Hampshire Univ., Durham, NH

1993-01-01

We review progress in our understanding the production and time evolution of the quark gluon plasma starting with boost invariant initial conditions in a filed theory model based on the Schwinger mechanism of particle production via tunneling

Adapting Digital Libraries to Continual Evolution

Science.gov (United States)

Barkstrom, Bruce R.; Finch, Melinda; Ferebee, Michelle; Mackey, Calvin

2002-01-01

In this paper, we describe five investment streams (data storage infrastructure, knowledge management, data production control, data transport and security, and personnel skill mix) that need to be balanced against short-term operating demands in order to maximize the probability of long-term viability of a digital library. Because of the rapid pace of information technology change, a digital library cannot be a static institution. Rather, it has to become a flexible organization adapted to continuous evolution of its infrastructure.

What about oil reserve depletion and crude oil price evolution?

International Nuclear Information System (INIS)

2007-01-01

The objective of this report is to give a synthesis of different points of view with respect to the 'Peak Oil' perspective and to the crude oil price evolution. In the first part, the authors examine the evolutions and assessments of oil reserves and productions, by discussing the different types of reserve, the optimistic and pessimistic points of views. Then, in the second part, they analyse the long term price formation, the various production technical costs (conventional oils, heavy oils and asphaltic sands, coal- and gas-based synthetic hydrocarbons, bio-fuels), the external costs (notably in relationship with greenhouse emissions), the relationship between geopolitical issues and short and middle term price formation. In the third and last part, they discuss the possible evolutions and scenarios in terms of demand, production, and prices

Integration of short bouts of physical activity into organizational routine a systematic review of the literature.

Science.gov (United States)

Barr-Anderson, Daheia J; AuYoung, Mona; Whitt-Glover, Melicia C; Glenn, Beth A; Yancey, Antronette K

2011-01-01

Recommended daily physical activity accumulated in short intervals (e.g., organizational routine as part of the regular "conduct of business." PubMed, MEDLINE, and Google Scholar databases were searched in August 2009 (updated search in February and July 2010) to identify relevant, peer-reviewed journal articles and abstracts on school-, worksite-, and faith-based interventions of short, structurally integrated physical activity breaks. The majority of interventions implemented daily physical activity bouts of 10-15 minutes in length. Schools were the most common settings among the 40 published articles included in this review. The rigor of the studies varied by setting, with more than 75% of worksite versus 25% of school studies utilizing RCT designs. Studies focused on a broad range of outcomes, including academic/work performance indicators, mental health outcomes, and clinical disease risk indicators, in addition to physical activity level. Physical activity was the most commonly assessed outcome in school-based studies, with more than half of studies assessing and observing improvements in physical activity outcomes following the intervention. About a quarter of worksite-based studies assessed physical activity, and the majority found a positive effect of the intervention on physical activity levels. About half of studies also observed improvements in other relevant outcomes such as academic and work performance indicators (e.g., academic achievement, cognitive performance, work productivity); psychosocial factors (e.g., stress, mood); and clinical disease risk indicators (e.g., blood pressure, BMI). The average study duration was more than 1 year, and several reported outcomes at 3-6 years. Interventions integrating physical activity into organizational routine during everyday life have demonstrated modest but consistent benefits, particularly for physical activity, and these are promising avenues of investigation. The proportionately longer-term outcomes

Contribution to the WWER-440 Gd-assembly evolution

International Nuclear Information System (INIS)

Cudrnak, P.; Darilek, P.; Necas, V.

2009-01-01

Development activities, presented in the paper, contribute to the evolution of gadolinium fuel for the WWER-440 reactors. Short overview of existing and already proposed Gd-assemblies is given. Two new assembly types with improved features are described. Multiplication coefficients and pin power peaking factors of all mentioned gadolinium assemblies are compared. Animations of power distribution behaviour in selected Gd-assemblies are shown. (Authors)

A short guide to peer-reviewed, MEDLINE-indexed complementary and alternative medicine journals.

Science.gov (United States)

Morgan, Sherry; Littman, Lynn; Palmer, Christina; Singh, Gurneet; LaRiccia, Patrick J

2012-01-01

Complementary and alternative medicine (CAM) comprises a multitude of disciplines, for example, acupuncture, ayurvedic medicine, biofeedback, herbal medicine, and homeopathic medicine. While research on CAM interventions has increased and the CAM literature has proliferated since the mid-1990s, a number of our colleagues have expressed difficulties in deciding where to publish CAM articles. In response, we created a short guide to peer-reviewed MEDLINE-indexed journals that publish CAM articles. We examined numerous English-language sources to identify titles that met our criteria, whether specific to or overlapping CAM. A few of the resources in which we found the journal titles that we included are Alternative Medicine Foundation, American Holistic Nurses Association, CINAHL/Nursing Database, Journal Citation Reports database, MEDLINE, PubMed, and Research Council for Complementary Medicine. We organized the 69 selected titles for easy use by creating 2 user-friendly tables, one listing titles in alphabetical order and one listing them in topical categories. A few examples of the topical categories are Acupuncture, CAM (general), Chinese Medicine, Herbal/Plant/Phytotherapy, Neuroscience/Psychology, Nursing/Clinical Care. Our study is the first to list general CAM journals, specialty CAM journals, and overlapping mainstream journals that are peer reviewed, in English, and indexed in MEDLINE. Our goal was to assist both authors seeking publication and mainstream journal editors who receive an overabundance of publishable articles but must recommend that authors seek publication elsewhere due to space and priority issues. Publishing in journals indexed by and included in MEDLINE (or PubMed) ensures that citations to articles will be found easily. Copyright © 2012 Lippincott Williams & Wilkins.

New Gene Evolution: Little Did We Know

Science.gov (United States)

Long, Manyuan; VanKuren, Nicholas W.; Chen, Sidi; Vibranovski, Maria D.

2014-01-01

Genes are perpetually added to and deleted from genomes during evolution. Thus, it is important to understand how new genes are formed and evolve as critical components of the genetic systems determining the biological diversity of life. Two decades of effort have shed light on the process of new gene origination, and have contributed to an emerging comprehensive picture of how new genes are added to genomes, ranging from the mechanisms that generate new gene structures to the presence of new genes in different organisms to the rates and patterns of new gene origination and the roles of new genes in phenotypic evolution. We review each of these aspects of new gene evolution, summarizing the main evidence for the origination and importance of new genes in evolution. We highlight findings showing that new genes rapidly change existing genetic systems that govern various molecular, cellular and phenotypic functions. PMID:24050177

Experimental Study of Thermal Field Evolution in the Short-Impending Stage Before Earthquakes

Science.gov (United States)

Ren, Yaqiong; Ma, Jin; Liu, Peixun; Chen, Shunyun

2017-08-01

Phenomena at critical points are vital for identifying the short-impending stage prior to earthquakes. The peak stress is a critical point when stress is converted from predominantly accumulation to predominantly release. We call the duration between the peak stress and instability "the meta-instability stage", which refers to the short-impending stage of earthquakes. The meta-instability stage consists of a steady releasing quasi-static stage and an accelerated releasing quasi-dynamic stage. The turning point of the above two stages is the remaining critical point. To identify the two critical points in the field, it is necessary to study the characteristic phenomena of various physical fields in the meta-instability stage in the laboratory, and the strain and displacement variations were studied. Considering that stress and relative displacement can be detected by thermal variations and peculiarities in the full-field observations, we employed a cooled thermal infrared imaging system to record thermal variations in the meta-instability stage of stick slip events generated along a simulated, precut planer strike slip fault in a granodiorite block on a horizontally bilateral servo-controlled press machine. The experimental results demonstrate the following: (1) a large area of decreasing temperatures in wall rocks and increasing temperatures in sporadic sections of the fault indicate entrance into the meta-instability stage. (2) The rapid expansion of regions of increasing temperatures on the fault and the enhancement of temperature increase amplitude correspond to the turning point from the quasi-static stage to the quasi-dynamic stage. Our results reveal thermal indicators for the critical points prior to earthquakes that provide clues for identifying the short-impending stage of earthquakes.

Population Thinking, Price’s Equation and the Analysis of Economic Evolution

DEFF Research Database (Denmark)

Andersen, Esben Sloth

2004-01-01

applicable to economic evolution due to the development of what may be called a general evometrics. Central to this evometrics is a method for partitioning evolutionary change developed by George Price into the selection effect and what may be called the innovation effect. This method serves surprisingly...... well as a means of accounting for evolution and as a starting point for the explanation of evolution. The applications of Price’s equation cover the partitioning and analysis of relatively short-term evolutionary change within individual industries as well as the study of more complexly structured...... populations of firms. By extrapolating these applications of Price’s evometrics, the paper suggests that his approach may play a central role in the emerging evolutionary econometrics....

TESTING MODELS OF MAGNETIC FIELD EVOLUTION OF NEUTRON STARS WITH THE STATISTICAL PROPERTIES OF THEIR SPIN EVOLUTIONS

International Nuclear Information System (INIS)

Zhang Shuangnan; Xie Yi

2012-01-01

We test models for the evolution of neutron star (NS) magnetic fields (B). Our model for the evolution of the NS spin is taken from an analysis of pulsar timing noise presented by Hobbs et al.. We first test the standard model of a pulsar's magnetosphere in which B does not change with time and magnetic dipole radiation is assumed to dominate the pulsar's spin-down. We find that this model fails to predict both the magnitudes and signs of the second derivatives of the spin frequencies (ν-double dot). We then construct a phenomenological model of the evolution of B, which contains a long-term decay (LTD) modulated by short-term oscillations; a pulsar's spin is thus modified by its B-evolution. We find that an exponential LTD is not favored by the observed statistical properties of ν-double dot for young pulsars and fails to explain the fact that ν-double dot is negative for roughly half of the old pulsars. A simple power-law LTD can explain all the observed statistical properties of ν-double dot. Finally, we discuss some physical implications of our results to models of the B-decay of NSs and suggest reliable determination of the true ages of many young NSs is needed, in order to constrain further the physical mechanisms of their B-decay. Our model can be further tested with the measured evolutions of ν-dot and ν-double dot for an individual pulsar; the decay index, oscillation amplitude, and period can also be determined this way for the pulsar.

Delayed treatment of decompression sickness with short, no-air-break tables: review of 140 cases.

Science.gov (United States)

Cianci, Paul; Slade, John B

2006-10-01

Most cases of decompression sickness (DCS) in the U.S. are treated with hyperbaric oxygen using U.S. Navy Treatment Tables 5 and 6, although detailed analysis shows that those tables were based on limited data. We reviewed the development of these protocols and offer an alternative treatment table more suitable for monoplace chambers that has proven effective in the treatment of DCS in patients presenting to our facility. We reviewed the outcomes for 140 cases of DCS in civilian divers treated with the shorter tables at our facility from January 1983 through December 2002. Onset of symptoms averaged 9.3 h after surfacing. At presentation, 44% of the patients demonstrated mental aberration. The average delay from onset of symptoms to treatment was 93.5 h; median delay was 48 h. Complete recovery in the total group of 140 patients was 87%. When 30 patients with low probability of DCS were excluded, the recovery rate was 98%. All patients with cerebral symptoms recovered. Patients with the highest severity scores showed a high rate of complete recovery (97.5%). Short oxygen treatment tables as originally described by Hart are effective in the treatment of DCS, even with long delays to definitive recompression that often occur among civilian divers presenting to a major Divers Alert Network referral center.

Experimental investigation of plasma dynamics in dc and short-pulse magnetron discharges

International Nuclear Information System (INIS)

Seo, Sang-Hun; In, Jung-Hwan; Chang, Hong-Young

2006-01-01

The spatiotemporal evolution of the electron energy distribution function (EEDF) and of plasma parameters such as the electron density, the electron temperature and the plasma and floating potentials has been investigated using spatially and temporally resolved single Langmuir probe measurements in dc and mid-frequency, short-pulse magnetron discharges with a repetition frequency of 10 kHz and a duty cycle of 10%. In the pulsed discharge of the short duty cycle, a peak electron temperature higher than 10 eV was observed near the cathode fall region during the early phase of the pulse-on, which is about three times higher than the steady-state value of the electron temperature in the dc discharge. The temporal evolution of the measured EEDFs showed the initial efficient electron heating during the early phase of the pulse-on and the subsequent relaxation of electron energy by the inelastic collisions and the diffusive loss. The high-energy electrons generated during the pulse-on phase diffused the downstream region toward the grounded substrate, resulting in a bi-Maxwellian EEDF consisting of the background low-energy electrons and the high-energy electrons. The results of the spatially and temporally resolved probe measurements will be presented and the enhanced efficiency of the electron heating in the short-pulse discharge will be explained on the basis of the global model of a pulsed discharge

Short Review on Quantum Key Distribution Protocols.

Science.gov (United States)

Giampouris, Dimitris

2017-01-01

Cryptographic protocols and mechanisms are widely investigated under the notion of quantum computing. Quantum cryptography offers particular advantages over classical ones, whereas in some cases established protocols have to be revisited in order to maintain their functionality. The purpose of this paper is to provide the basic definitions and review the most important theoretical advancements concerning the BB84 and E91 protocols. It also aims to offer a summary on some key developments on the field of quantum key distribution, closely related with the two aforementioned protocols. The main goal of this study is to provide the necessary background information along with a thorough review on the theoretical aspects of QKD, concentrating on specific protocols. The BB84 and E91 protocols have been chosen because most other protocols are similar to these, a fact that makes them important for the general understanding of how the QKD mechanism functions.

Systematic analysis of short internal indels and their impact on protein folding

Directory of Open Access Journals (Sweden)

Guo Jun-tao

2010-08-01

Full Text Available Abstract Background Protein sequence insertions/deletions (indels can be introduced during evolution or through alternative splicing (AS. Alternative splicing is an important biological phenomenon and is considered as the major means of expanding structural and functional diversity in eukaryotes. Knowledge of the structural changes due to indels is critical to our understanding of the evolution of protein structure and function. In addition, it can help us probe the evolution of alternative splicing and the diversity of functional isoforms. However, little is known about the effects of indels, in particular the ones involving core secondary structures, on the folding of protein structures. The long term goal of our study is to accurately predict the protein AS isoform structures. As a first step towards this goal, we performed a systematic analysis on the structural changes caused by short internal indels through mining highly homologous proteins in Protein Data Bank (PDB. Results We compiled a non-redundant dataset of short internal indels (2-40 amino acids from highly homologous protein pairs and analyzed the sequence and structural features of the indels. We found that about one third of indel residues are in disordered state and majority of the residues are exposed to solvent, suggesting that these indels are generally located on the surface of proteins. Though naturally occurring indels are fewer than engineered ones in the dataset, there are no statistically significant differences in terms of amino acid frequencies and secondary structure types between the "Natural" indels and "All" indels in the dataset. Structural comparisons show that all the protein pairs with short internal indels in the dataset preserve the structural folds and about 85% of protein pairs have global RMSDs (root mean square deviations of 2Å or less, suggesting that protein structures tend to be conserved and can tolerate short insertions and deletions. A few pairs

The Evolution of American Hospital Ethics Committees: A Systematic Review.

Science.gov (United States)

Courtwright, Andrew; Jurchak, Martha

2016-01-01

During the 1970s and 1980s, legal precedent, governmental recommendations, and professional society guidelines drove the formation of hospital ethics committees (HECs). The Joint Commission on Accreditation of Health Care Organization's requirements in the early 1990s solidified the role of HECs as the primary mechanism to address ethical issues in patient care. Because external factors drove the rapid growth of HECs on an institution-by-institution basis, however, no initial consensus formed around the structure and function of these committees. There are now almost 40 years of empirical studies on the composition, administration, and activities of HECs in the United States. We conducted a systematic review of the available empirical literature on HECs to describe their evolution. As HECs changed over time, they increased their total number of members and percentage of members from nursing and the community. Although physicians increasingly chaired these committees, their presence as a percentage of overall members declined. The percentage of administrative members remained steady, although committees became increasingly likely to have at least one administrative member. HECs were also increasingly likely to report to an administrative body or to the board of trustees or directors rather than to the medical staff. Finally, consultation volume increased steadily over time. There has not, however, been a national survey of the composition of ethics committees, their administration, or volume of consultation in more than 10 years, despite increasing calls for professional standards and quality improvement assessments among HECs. Copyright 2016 The Journal of Clinical Ethics. All rights reserved.

Evolution of consciousness of exposure to siloxanes-review of publications.

Science.gov (United States)

Mojsiewicz-Pieńkowska, Krystyna; Krenczkowska, Dominika

2018-01-01

The purpose of this description is to review scientific literature from 1944 to 2017 as a source of information on the reasons for the increased interest in siloxanes (silicones). Not only the research area, but first, the changes in the tendency of research aims are important issues in the evaluation. On the one hand, the authors emphasize the unique properties of linear and cyclic siloxanes, providing many examples of beneficial applications, and on the other hand, there are some warnings of overcoming of the safety barrier of their presence in human environment. Analyzing the results from the SCOPUS database, it can be argued that the increased interest of scientists and government agencies particularly relates to the analysis of siloxanes in biological and environmental samples. This is caused not only by the widespread use of various siloxanes in the pharmaceutical, medical, cosmetic and food industries, but also by the direct contact of these compounds with tissues, as well as an increased access to knowledge and modern research tools that have developed the awareness of hazards. The development of research methods enables not only constant monitoring of progressively lower siloxanes concentrations in various samples, but because of the specificity of these methods, it also enables an identification of specific siloxane compounds and evaluation of their effects on humans and environment. This paper discusses the issues of the evolution of consciousness of exposure to siloxanes due to their increased synthesis and widespread use in many areas of human life, which contributes to environmental pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Historical review of short-lived isotope applications in New Zealand

International Nuclear Information System (INIS)

More, R.D.

1986-01-01

Production of short-lived isotopes, nitrogen 13, fluorine 18 and carbon 11 with a small Van de Graaff accelerator. Applications of these isotopes in uptake and photosynthetic translocation studies in plants, and fluorine tracing in dental studies

Probabilistic eruption forecasting at short and long time scales

Science.gov (United States)

Marzocchi, Warner; Bebbington, Mark S.

2012-10-01

Any effective volcanic risk mitigation strategy requires a scientific assessment of the future evolution of a volcanic system and its eruptive behavior. Some consider the onus should be on volcanologists to provide simple but emphatic deterministic forecasts. This traditional way of thinking, however, does not deal with the implications of inherent uncertainties, both aleatoric and epistemic, that are inevitably present in observations, monitoring data, and interpretation of any natural system. In contrast to deterministic predictions, probabilistic eruption forecasting attempts to quantify these inherent uncertainties utilizing all available information to the extent that it can be relied upon and is informative. As with many other natural hazards, probabilistic eruption forecasting is becoming established as the primary scientific basis for planning rational risk mitigation actions: at short-term (hours to weeks or months), it allows decision-makers to prioritize actions in a crisis; and at long-term (years to decades), it is the basic component for land use and emergency planning. Probabilistic eruption forecasting consists of estimating the probability of an eruption event and where it sits in a complex multidimensional time-space-magnitude framework. In this review, we discuss the key developments and features of models that have been used to address the problem.

Dynamical evolution of short-wave instability in LHD

International Nuclear Information System (INIS)

Miura, H.; Nakajima, N.

2009-01-01

Full text: Dynamical growth of ballooning modes with high poloidal(m) /toroidal(n) Fourier coefficients (higher m/n modes) in the Large Helical Device (LHD) is studied by means of full 3D nonlinear simulations. Influences of higher modes on low modes are studied numerically. In the LHD experiments, some MHD activities are observed but the activities do not bring about serious deteriorations of plasma profiles and high beta-values have been achieved. For the sake of understanding the mild saturation of the instability, some numerical simulations have been carried out. However, the earlier works focus on low modes and dynamical behaviors of high modes are not understood well. In order to understand the dynamical evolution of the pressure-driven high-modes and clarify their influences on growth of low-modes, full-3D simulations of high Reynolds number LHD plasma are carried out for the magnetic field with the vacuum magnetic axis position 3.6m, the peak beta value 3.7%, and the reference Reynolds number Re=10 6 . In the simulations, the growth of ballooning modes up to n=15 toroidal wave-number is identified. The simultaneous growth of multiple ballooning modes brings about total modification of the pressure profile, showing that the pressure-flattening mechanism can not suppress the growth of the modes. On the other hand, a mild saturation of the unstable mode is obtained in another simulation with the relatively large parallel heat conduction, suggesting that the mild saturations might be rather contributed by the dissipative effects (typically by the parallel heat conduction) than the nonlinear mechanism such as the modifications of the pressure profiles. We also find that the wave-length of the n=15 ballooning mode is comparable to the ion skin-depth, suggesting the necessity of studying the high modes in the framework of the Hall-MHD dynamics. Studying the dynamics of the LHD plasmas by the use of the Hall-MHD or some sort of the two-fluid system is considered

The use of standardised short-term and working memory tests in aphasia research: a systematic review.

Science.gov (United States)

Murray, Laura; Salis, Christos; Martin, Nadine; Dralle, Jenny

2018-04-01

Impairments of short-term and working memory (STM, WM), both verbal and non-verbal, are ubiquitous in aphasia. Increasing interest in assessing STM and WM in aphasia research and clinical practice as well as a growing evidence base of STM/WM treatments for aphasia warrant an understanding of the range of standardised STM/WM measures that have been utilised in aphasia. To date, however, no previous systematic review has focused on aphasia. Accordingly, the goals of this systematic review were: (1) to identify standardised tests of STM and WM utilised in the aphasia literature, (2) to evaluate critically the psychometric strength of these tests, and (3) to appraise critically the quality of the investigations utilising these tests. Results revealed that a very limited number of standardised tests, in the verbal and non-verbal domains, had robust psychometric properties. Standardisation samples to elicit normative data were often small, and most measures exhibited poor validity and reliability properties. Studies using these tests inconsistently documented demographic and aphasia variables essential to interpreting STM/WM test outcomes. In light of these findings, recommendations are provided to foster, in the future, consistency across aphasia studies and confidence in STM/WM tests as assessment and treatment outcome measures.

Solar ultraviolet irradiance variations: a review

International Nuclear Information System (INIS)

Lean, J.

1987-01-01

Despite the geophysical importance of solar ultraviolet radiation, specific aspects of its temporal variations have not yet been adequately determined experimentally, nor are the mechanisms for the variability completely understood. Satellite observations have verified the reality of solar ultraviolet irradiance variations over time scales of days and months, and model calculations have confirmed the association of these short-term variations with the evolution and rotation of regions of enhanced magnetic activity on the solar disc. However, neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11-year solar cycle. The comparative importance for the long-term variations of local regions of enhanced magnetic activity and global scale activity perturbations is still being investigated. Solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. Correlations with ground-based measures of solar variability are examined because of the importance of the ground-based observations as historical proxies of ultraviolet irradiance variations. Current problems in understanding solar ultraviolet irradiance variations are discussed, and the measurements planned for solar cycle 22, which may resolve these problems, are briefly described. copyright American Geophysical Union 1987

Final phases of stellar evolution and the supernova phenomenon

Energy Technology Data Exchange (ETDEWEB)

Gallino, R [Torino, Universita, Turin, Italy; Masani, A [CNR, Laboratorio di Cosmo-geofisica, Turin, Italy

1977-12-01

Various theoretical aspects of the final stages of stellar evolution are reviewed in the framework of gravitational collapse and thermonuclear reactions (C-12 and O-16) in degenerate electron conditions. Attention is given to the evolution of supermassive stars, massive stars, and low-mass stars and to such topics as neutrino emission in intermediate-mass stars, white-dwarf supernovae, rotational instability, and stellar collisions and eclipsing binary systems.

Meta-analysis reveals evolution in invasive plant species but little support for Evolution of Increased Competitive Ability (EICA).

Science.gov (United States)

Felker-Quinn, Emmi; Schweitzer, Jennifer A; Bailey, Joseph K

2013-03-01

Ecological explanations for the success and persistence of invasive species vastly outnumber evolutionary hypotheses, yet evolution is a fundamental process in the success of any species. The Evolution of Increased Competitive Ability (EICA) hypothesis (Blossey and Nötzold 1995) proposes that evolutionary change in response to release from coevolved herbivores is responsible for the success of many invasive plant species. Studies that evaluate this hypothesis have used different approaches to test whether invasive populations allocate fewer resources to defense and more to growth and competitive ability than do source populations, with mixed results. We conducted a meta-analysis of experimental tests of evolutionary change in the context of EICA. In contrast to previous reviews, there was no support across invasive species for EICA's predictions regarding defense or competitive ability, although invasive populations were more productive than conspecific native populations under noncompetitive conditions. We found broad support for genetically based changes in defense and competitive plant traits after introduction into new ranges, but not in the manner suggested by EICA. This review suggests that evolution occurs as a result of plant introduction and population expansion in invasive plant species, and may contribute to the invasiveness and persistence of some introduced species.

REVIEW ARTICLE The evolution of religious belief in humans: A ...

Indian Academy of Sciences (India)

Navya

2017-04-04

Apr 4, 2017 ... evolution, were co-opted for use in flight, which then became a ... activates the same regions as when actual faces are seen and recognized in everyday life, and ... our evolutionary needs kicked in and gave rise to morality.

Etiology of lumbar lordosis and its pathophysiology: a review of the evolution of lumbar lordosis, and the mechanics and biology of lumbar degeneration.

Science.gov (United States)

Sparrey, Carolyn J; Bailey, Jeannie F; Safaee, Michael; Clark, Aaron J; Lafage, Virginie; Schwab, Frank; Smith, Justin S; Ames, Christopher P

2014-05-01

The goal of this review is to discuss the mechanisms of postural degeneration, particularly the loss of lumbar lordosis commonly observed in the elderly in the context of evolution, mechanical, and biological studies of the human spine and to synthesize recent research findings to clinical management of postural malalignment. Lumbar lordosis is unique to the human spine and is necessary to facilitate our upright posture. However, decreased lumbar lordosis and increased thoracic kyphosis are hallmarks of an aging human spinal column. The unique upright posture and lordotic lumbar curvature of the human spine suggest that an understanding of the evolution of the human spinal column, and the unique anatomical features that support lumbar lordosis may provide insight into spine health and degeneration. Considering evolution of the skeleton in isolation from other scientific studies provides a limited picture for clinicians. The evolution and development of human lumbar lordosis highlight the interdependence of pelvic structure and lumbar lordosis. Studies of fossils of human lineage demonstrate a convergence on the degree of lumbar lordosis and the number of lumbar vertebrae in modern Homo sapiens. Evolution and spine mechanics research show that lumbar lordosis is dictated by pelvic incidence, spinal musculature, vertebral wedging, and disc health. The evolution, mechanics, and biology research all point to the importance of spinal posture and flexibility in supporting optimal health. However, surgical management of postural deformity has focused on restoring posture at the expense of flexibility. It is possible that the need for complex and costly spinal fixation can be eliminated by developing tools for early identification of patients at risk for postural deformities through patient history (genetics, mechanics, and environmental exposure) and tracking postural changes over time.

Rapidly Evoluting Congenital Cystic Neuroblastoma in a Neonate

Energy Technology Data Exchange (ETDEWEB)

Yun, Tae Jun; Kim, Myung Jun; Han, Seok Joo; Lee, Mi Jung [Severance Children' s Hospital, Yonsei University, College of Medicine, Seoul(Korea, Republic of)

2012-08-15

Perinatal detection of neonatal suprarenal masses has increased. Here, we report an unusual case of an adrenal cystic neuroblastoma that presented as a purely cystic lesion upon initial postnatal ultrasonography (US) and showed rapid evolution to a mixed cystic and solid mass during follow-up US and MRI. We suggest a short-term (two weeks) follow-up US for neonatal adrenal cystic lesions, even if they appear as purely cystic.

Peculiarities of the propagation of multidimensional extremely short optical pulses in germanene

Energy Technology Data Exchange (ETDEWEB)

Zhukov, Alexander V., E-mail: alex_zhukov@sutd.edu.sg [Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore (Singapore); Bouffanais, Roland [Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore (Singapore); Konobeeva, Natalia N. [Volgograd State University, 400062 Volgograd (Russian Federation); Belonenko, Mikhail B. [Laboratory of Nanotechnology, Volgograd Institute of Business, 400048 Volgograd (Russian Federation); Volgograd State University, 400062 Volgograd (Russian Federation)

2016-09-07

Highlights: • Established dynamics of ultra-short pulses in germanene. • Studied balance between dispersive and nonlinear effects in germanene. • Spin–orbit interaction effect onto pulse propagation. - Abstract: In this Letter, we study the propagation characteristics of both two-dimensional and three-dimensional extremely short optical pulses in germanene. A distinguishing feature of germanene—in comparison with other graphene-like structures—is the presence of a significant spin–orbit interaction. The account of this interaction has a significant impact on the evolution of extremely short pulses in such systems. Specifically, extremely short optical pulses, consisting of two electric field oscillations, cause the appearance of a tail associated with the excitation of nonlinear waves. Due to the large spin–orbit interaction in germanene, this tail behind the main pulse is much smaller in germanene-based samples as compared to graphene-based ones, thereby making germanene a preferred material for the stable propagation of pulses along the sample.

Technical note 5. SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC. Contribution to the Initial Review Phase

International Nuclear Information System (INIS)

Benbow, Steven; Metcalfe, Richard; Watson, Claire; Bond, Alex

2012-06-01

This review has focussed mainly on the modelling of the Engineered Barrier System (EBS) evolution, which includes coupled thermal, hydraulic, mechanical and chemical (THMC) processes. Additionally, the role of the EBS in the wider safety case was reviewed, including its treatment in scenarios and its representation in conceptual models since this provided the motivation for the modelling work that was undertaken by SKB. The scope of the work described here was to: 1. Review relevant documents concerning SKB's modelling; and 2. Check one particular modelling area that was judged to be important, based on this review, with a limited set of independent modelling/calculations. The review covers the early resaturation and swelling / homogenisation of the buffer; the longer-term chemical evolution of the buffer and backfill, corrosion of the copper canister and the chemical and hydrogeological boundary conditions provided by the surrounding host rock. The reviewers consider that SKB's modelling of engineered barrier performance generally supports their conclusion that the barriers will perform as required. However, there remain issues that are not addressed and uncertainties that are not explored adequately by SKB's modelling. The thermo-hydro-mechanical modelling of buffer resaturation that is performed by SKB is based on demonstrating a fit to measurements from the in-situ Canister Retrieval Test (CRT) experiment. The modelling reproduces some of the experimental observations very well, but some key experimental measurements are not considered. In particular, investigation of the fit to the measured rates of water inflow, which are a critical factor controlling the rate at which the buffer will resaturate, is not given, Furthermore, the water supply boundary conditions imposed on the CRT are not considered to be representative of those that might be expected in repository conditions. From the information that it is presented it is therefore not possible to be confident

Microstructural evolution under high temperature irradiation: fundamental aspects

International Nuclear Information System (INIS)

Martin, G.; Valentin, P.

1984-01-01

In view of the impossibility to propose theoretically established scaling laws for extrapolating microstructural evolutions to unknown irradiation conditions, a full modelization of microstructural evolution at the atomistic level cannot be avoided. We briefly review the main models available for describing: defect balance under irradiation, the nucleation of clusters of various types, the development of each of the components of the microstructure, synergistic effects among the latter. Attention is called on the problems which remain to be solved at each step. In particular, the swelling incubation phenomenon is just being studied from the fundamental viewpoint. A table of available relevant observations thereof is given. The existence of dose-rate thresholds accross which microstructural evolution undergoes a qualitative change is stressed. Such thresholds call for a detailed modelization of microstructural evolution in order to propose safe extrapolation techniques [fr

Load transfer in short fibre reinforced metal matrix composites

International Nuclear Information System (INIS)

Garces, Gerardo; Bruno, Giovanni; Wanner, Alexander

2007-01-01

The internal load transfer and the deformation behaviour of aluminium-matrix composites reinforced with 2D-random alumina (Saffil) short fibres was studied for different loading modes. The evolution of stress in the metallic matrix was measured by neutron diffraction during in situ uniaxial deformation tests. Tensile and compressive tests were performed with loading axis parallel or perpendicular to the 2D-reinforcement plane. The fibre stresses were computed based on force equilibrium considerations. The results are discussed in light of a model recently established by the co-authors for composites with visco-plastic matrix behaviour and extended to the case of plastic deformation in the present study. Based on that model, the evolution of internal stresses and the macroscopic stress-strain were simulated. Comparison between the experimental and computational results shows a qualitative agreement in all relevant aspects

Conceptualizing the origin of life in terms of evolution

Science.gov (United States)

Takeuchi, N.; Hogeweg, P.; Kaneko, K.

2017-11-01

In this opinion piece, we discuss how to place evolution in the context of origin-of-life research. Our discussion starts with a popular definition: `life is a self-sustained chemical system capable of undergoing Darwinian evolution'. According to this definition, the origin of life is the same as the origin of evolution: evolution is the `end' of the origin of life. This perspective, however, has a limitation, in that the ability of evolution in and of itself is insufficient to explain the origin of life as we know it, as indicated by Spiegelman's and Lincoln and Joyce's experiments. This limitation provokes a crucial question: What conditions are required for replicating systems to evolve into life? From this perspective, the origin of life includes the emergence of life through evolution: evolution is a `means' of the origin of life. After reviewing Eigen's pioneering work on this question, we mention our ongoing work suggesting that a key condition might be conflicting multi-level evolution. Taken together, there are thus two questions regarding the origin of life: how evolution gets started, and how evolution produces life. Evolution is, therefore, at the centre of the origin of life, where the two lines of enquiry must meet. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Short-term plasticity as a neural mechanism supporting memory and attentional functions.

Science.gov (United States)

Jääskeläinen, Iiro P; Ahveninen, Jyrki; Andermann, Mark L; Belliveau, John W; Raij, Tommi; Sams, Mikko

2011-11-08

Based on behavioral studies, several relatively distinct perceptual and cognitive functions have been defined in cognitive psychology such as sensory memory, short-term memory, and selective attention. Here, we review evidence suggesting that some of these functions may be supported by shared underlying neuronal mechanisms. Specifically, we present, based on an integrative review of the literature, a hypothetical model wherein short-term plasticity, in the form of transient center-excitatory and surround-inhibitory modulations, constitutes a generic processing principle that supports sensory memory, short-term memory, involuntary attention, selective attention, and perceptual learning. In our model, the size and complexity of receptive fields/level of abstraction of neural representations, as well as the length of temporal receptive windows, increases as one steps up the cortical hierarchy. Consequently, the type of input (bottom-up vs. top down) and the level of cortical hierarchy that the inputs target, determine whether short-term plasticity supports purely sensory vs. semantic short-term memory or attentional functions. Furthermore, we suggest that rather than discrete memory systems, there are continuums of memory representations from short-lived sensory ones to more abstract longer-duration representations, such as those tapped by behavioral studies of short-term memory. Copyright © 2011 Elsevier B.V. All rights reserved.

Sorting signed permutations by short operations.

Science.gov (United States)

Galvão, Gustavo Rodrigues; Lee, Orlando; Dias, Zanoni

2015-01-01

During evolution, global mutations may alter the order and the orientation of the genes in a genome. Such mutations are referred to as rearrangement events, or simply operations. In unichromosomal genomes, the most common operations are reversals, which are responsible for reversing the order and orientation of a sequence of genes, and transpositions, which are responsible for switching the location of two contiguous portions of a genome. The problem of computing the minimum sequence of operations that transforms one genome into another - which is equivalent to the problem of sorting a permutation into the identity permutation - is a well-studied problem that finds application in comparative genomics. There are a number of works concerning this problem in the literature, but they generally do not take into account the length of the operations (i.e. the number of genes affected by the operations). Since it has been observed that short operations are prevalent in the evolution of some species, algorithms that efficiently solve this problem in the special case of short operations are of interest. In this paper, we investigate the problem of sorting a signed permutation by short operations. More precisely, we study four flavors of this problem: (i) the problem of sorting a signed permutation by reversals of length at most 2; (ii) the problem of sorting a signed permutation by reversals of length at most 3; (iii) the problem of sorting a signed permutation by reversals and transpositions of length at most 2; and (iv) the problem of sorting a signed permutation by reversals and transpositions of length at most 3. We present polynomial-time solutions for problems (i) and (iii), a 5-approximation for problem (ii), and a 3-approximation for problem (iv). Moreover, we show that the expected approximation ratio of the 5-approximation algorithm is not greater than 3 for random signed permutations with more than 12 elements. Finally, we present experimental results that show

A short review of headspace extraction and ultrasonic solvent extraction for honey volatiles fingerprinting

Directory of Open Access Journals (Sweden)

Z. Marijanović

2009-01-01

Full Text Available Honey volatiles exhibit a potential role in distinguishing honeys as a function of botanical origin, but heating of honey generates artefacts such as compounds of Strecker degradation and Maillard reaction products. This short review is focused on the most recently applied methods for honey volatiles fingerprinting (without generation of thermal artefacts: headspace extraction (dynamic headspace extraction (DHE, headspace solid-phase microextraction (HS-SPME and ultrasonic solvent extraction (USE. These methods display a varying degree of selectivity and effectiveness depending upon the compounds involved and the extraction conditions. Recent developments of these methods are discussed, with application examples drawn from the literature as well from our own research. Flavour qualities of the honey are very much dependent on the volatile and semivolatile organic compounds present in both the sample matrix and the headspace aroma. Therefore the use of one single technique is not adequate for reliable honey volatiles profiling, but combined use of headspace extraction and ultrasonic solvent extraction could be a useful tool for the characterization of the honey and identification of its botanical source through typical volatile marker compounds.

Casticin from Vitex species: a short review on its anticancer and anti-inflammatory properties.

Science.gov (United States)

Chan, Eric Wei Chiang; Wong, Siu Kuin; Chan, Hung Tuck

2018-05-01

This short review provides an update of the anticancer and anti-inflammatory properties of casticin from Vitex species. Casticin is a polymethylflavone with three rings, an orthocatechol moiety, a double bond, two hydroxyl groups and four methoxyl groups. Casticin has been isolated from various tissues of plants in the Vitex genus: fruits and leaves of V. trifolia, aerial parts and seeds of V. agnus-castus and leaves of V. negundo. Studies have reported the antiproliferative and apoptotic activities of casticin from Vitex species. The compound is effective against many cancer cell lines via different molecular mechanisms. Studies have also affirmed the anti-inflammatory properties of casticin, with several molecular mechanisms identified. Other pharmacological properties include anti-asthmatic, tracheospasmolytic, analgesic, antihyperprolactinemia, immunomodulatory, opioidergic, oestrogenic, anti-angiogenic, antiglioma, lung injury protection, rheumatoid arthritis amelioration and liver fibrosis attenuation activities. Clinical trials and commercial use of the casticin-rich fruit extract of V. agnus-castus among women with premenstrual syndrome were briefly discussed. Copyright © 2018 Shanghai Changhai Hospital. Published by Elsevier B.V. All rights reserved.

Short sleep duration and dietary intake: epidemiological evidence, mechanisms, and health implications

Science.gov (United States)

Links between short sleep duration and obesity, type 2 diabetes, hypertension, and cardiovascular disease may be mechanistically mediated through changes in dietary intake. This review aims to provide an overview of recent epidemiologic studies on the relationships between habitual short sleep durat...

Percutaneous Image-Guided Screw Fixation of Bone Lesions in Cancer Patients: Double-Centre Analysis of Outcomes including Local Evolution of the Treated Focus

Energy Technology Data Exchange (ETDEWEB)

Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Koch, Guillaume, E-mail: guillaume.koch@chru-strasbourg.fr [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France); Buy, Xavier, E-mail: x.buy@bordeaux.unicancer.fr [Institut Bergonié, Department of Radiology (France); Ramamurthy, Nitin, E-mail: nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Tsoumakidou, Georgia, E-mail: georgia.tsoumakidou@chru-strasbourg.fr; Caudrelier, Jean, E-mail: jean.caudrelier@chru-strasbourg.fr [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France); Catena, Vittorio, E-mail: v.catena@bordeaux.unicancer.fr [Institut Bergonié, Department of Radiology (France); Garnon, Julien, E-mail: juleiengarnon@gmail.com [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France); Palussiere, Jean, E-mail: j.palussiere@bordeaux.unicancer.fr [Institut Bergonié, Department of Radiology (France); Gangi, Afshin, E-mail: gangi@unistra.fr [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France)

2016-10-15

AimTo review outcomes and local evolution of treated lesions following percutaneous image-guided screw fixation (PIGSF) of pathological/insufficiency fractures (PF/InF) and impeding fractures (ImF) in cancer patients at two tertiary centres.Materials and methodsThirty-two consecutive patients (mean age 67.5 years; range 33–86 years) with a range of tumours and prognoses underwent PIGSF for non/minimally displaced PF/InF and ImF. Screws were placed under CT/fluoroscopy or cone-beam CT guidance, with or without cementoplasty. Clinical outcomes were assessed using a simple 4-point scale (1 = worse; 2 = stable; 3 = improved; 4 = significantly improved). Local evolution was reviewed on most recent follow-up imaging. Technical success, complications, and overall survival were evaluated.ResultsThirty-six lesions were treated with 74 screws mainly in the pelvis and femoral neck (58.2 %); including 47.2 % PF, 13.9 % InF, and 38.9 % ImF. Cementoplasty was performed in 63.9 % of the cases. Technical success was 91.6 %. Hospital stay was ≤3 days; 87.1 % of lesions were improved at 1-month follow-up; three major complications (early screw-impingement radiculopathy; accelerated coxarthrosis; late coxofemoral septic arthritis) and one minor complication were observed. Unfavourable local evolution at imaging occurred in 3/24 lesions (12.5 %) at mean 8.7-month follow-up, including poor consolidation (one case) and screw loosening (two cases, at least 1 symptomatic). There were no cases of secondary fractures.ConclusionsPIGSF is feasible for a wide range of oncologic patients, offering good short-term efficacy, acceptable complication rates, and rapid recovery. Unfavourable local evolution at imaging may be relatively frequent, and requires close clinico-radiological surveillance.

Uptake and metabolism of the short-chain fatty acid butyrate, a critical review of the literature.

Science.gov (United States)

Astbury, Stuart M; Corfe, Bernard M

2012-07-01

Butyrate is a short-chain fatty acid (SCFA) formed by bacterial fermentation of fibre in the colon, and serves as an energy source for colonocytes. The action of butyrate as a histone deacetylase inhibitor (HDACi) has led to a number of clinical trials testing its effectiveness as a potential treatment for cancer. The biology of butyrate transport is therefore relevant to both its physiological and pharmacological benefits. This review of the literature was carried out to assess the evidence for both the uptake and metabolism of butyrate, in an attempt to determine possible mechanism (s) by which butyrate can act as an HDACi. It is noted that although uptake and metabolism are well characterised, there are still significant gaps in the knowledgebase around the intracellular handing of butyrate, where assumptions or dated evidence are relied upon.

Ultrasound-guided continuous suprascapular nerve block for adhesive capsulitis: one case and a short topical review

DEFF Research Database (Denmark)

Neimann, Jens Dupont Børglum; Bartholdy, Anne; Hautopp, H

2011-01-01

We present a case with an ultrasound-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the suprascapular nerve (SSN). The patient suffered from a severe and very painful adhesive capsulitis of the left...... shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low...... impact passive and guided active mobilization by the performing physiotherapist for three consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlight the possibility of a USG continuous nerve block of the SSN as sufficient pain management...

Technological Advances in Stent Therapies: a Year in Review.

Science.gov (United States)

Raffoul, Jad; Nasir, Ammar; Klein, Andrew J P

2018-04-07

Stent technology has rapidly evolved since the first stainless steel bare metal stents with substantial developments in scaffolding, polymer, drug choice, drug delivery, and elution mechanisms. Most recently, there has been the evolution of bioabsorbable vascular scaffolds, potentially eliminating the need for long-term foreign object retention. These rapid developments have led to an ever-expanding selection of new stents, making the choice of which to use in which patient challenging. Operators must balance potential short- and long-term clinical ramifications, namely stent thrombosis, in-stent restenosis, target lesion revascularization, and target lesion failure. In this review, we hope to provide insight for interventional cardiologists on the details of stent technology and how this impacts outcomes, stent selection, and duration of dual-antiplatelet therapy duration post drug-eluting stent implantation.

Models of sarcopenia: Short review.

Science.gov (United States)

Palus, S; Springer, J I; Doehner, W; von Haehling, S; Anker, M; Anker, S D; Springer, J

2017-07-01

Approximately 40-50% of the population over 80years of age suffers from sarcopenia making this condition a major geriatric clinical disorder and a key challenge to healthy aging. The hallmark symptom of sarcopenia is the loss of muscle mass and strength without the loss of overall body weight. Sarcopenic patients are likely to have worse clinical outcomes and higher mortality compared to healthy individuals. This review will focus on animal models designed to study sarcopenia including hind-limb unloading, de-nervation, and immobilization by using casts or wire strategies, as well as using aged rodents. Currently there are no registered treatments for sarcopenia. Most sarcopenic individuals show signs of physical frailty, which leads to increases the prevalence of balance disorders, falls, fractures and pain. Therefore, is it essential to develop and use relevant animal models to further the research on sarcopenia therapy? Copyright © 2017 Elsevier B.V. All rights reserved.

Hard probes of short-range nucleon-nucleon correlations

Energy Technology Data Exchange (ETDEWEB)

J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian

2012-10-01

The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nuclei and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.

Short Communication: Evolution of HIV-1 Coreceptor Usage and Coreceptor Switching During Pregnancy

OpenAIRE

Ransy, Doris G.; Motorina, Alena; Merindol, Natacha; Akouamba, Bertine S.; Samson, Johanne; Lie, Yolanda; Napolitano, Laura A.; Lapointe, Normand; Boucher, Marc; Soudeyns, Hugo

2014-01-01

Coreceptor switch from CCR5 to CXCR4 is associated with HIV disease progression. To document the evolution of coreceptor tropism during pregnancy, a longitudinal study of envelope gene sequences was performed in a group of pregnant women infected with HIV-1 of clade B (n=10) or non-B (n=9). Polymerase chain reaction (PCR) amplification of the V1-V3 region was performed on plasma viral RNA, followed by cloning and sequencing. Using geno2pheno and PSSMX4R5, the presence of X4 variants was predi...

Evolution of parton densities beyond leading order

International Nuclear Information System (INIS)

Curci, G.; Petronzio, R.; Furmanski, W.

1980-01-01

We develop a technique, based explicitly on the factorization properties of mass singularities, which allows one to calculate the evolution of parton densities beyond leading order. We present the results for the evolution of hadronic structure functions as well as for parton fragmentation functions into hadrons. Within our scheme the predictions for a particular process are obtained by convoluting a universal parton density with a short-distance cross section specific to the process. As an application, we calculate the QCD predictions for the Q 2 dependence of deep inelastic lepton-hadron scattering and of one-particle inclusive e + e - annihilation cross sections. Our results for electroproduction agree with those obtained with the operator product expansion technique. Physical quantitites in scattering are related to the corresponding ones in annihilation by analytic continuation, whereas the Gribov-Lipatov relation is strongly violated. (orig.)

Short RNA guides cleavage by eukaryotic RNase III.

Directory of Open Access Journals (Sweden)

Bruno Lamontagne

Full Text Available In eukaryotes, short RNAs guide a variety of enzymatic activities that range from RNA editing to translation repression. It is hypothesized that pre-existing proteins evolved to bind and use guide RNA during evolution. However, the capacity of modern proteins to adopt new RNA guides has never been demonstrated. Here we show that Rnt1p, the yeast orthologue of the bacterial dsRNA-specific RNase III, can bind short RNA transcripts and use them as guides for sequence-specific cleavage. Target cleavage occurred at a constant distance from the Rnt1p binding site, leaving the guide RNA intact for subsequent cleavage. Our results indicate that RNase III may trigger sequence-specific RNA degradation independent of the RNAi machinery, and they open the road for a new generation of precise RNA silencing tools that do not trigger a dsRNA-mediated immune response.

Nuclear program review

International Nuclear Information System (INIS)

Brito, S.; Rosa, L.P.; Carvalho, Joaquim de; Simon, D.N.

1985-01-01

A review of the Brazilian Nuclear Program based in Brazilian energy perspectives, in world-wide technology evolution and in international and national economic context is done. The objetive is look for subsidies for new decisions related to the future of program, taking in account the acquired experience and new data created by evolution of internal and external political and technological conjuncture. (M.C.K.) [pt

Cyanobacterial evolution during the Precambrian

Science.gov (United States)

Schirrmeister, Bettina E.; Sanchez-Baracaldo, Patricia; Wacey, David

2016-07-01

Life on Earth has existed for at least 3.5 billion years. Yet, relatively little is known of its evolution during the first two billion years, due to the scarceness and generally poor preservation of fossilized biological material. Cyanobacteria, formerly known as blue green algae were among the first crown Eubacteria to evolve and for more than 2.5 billion years they have strongly influenced Earth's biosphere. Being the only organism where oxygenic photosynthesis has originated, they have oxygenated Earth's atmosphere and hydrosphere, triggered the evolution of plants -being ancestral to chloroplasts- and enabled the evolution of complex life based on aerobic respiration. Having such a strong impact on early life, one might expect that the evolutionary success of this group may also have triggered further biosphere changes during early Earth history. However, very little is known about the early evolution of this phylum and ongoing debates about cyanobacterial fossils, biomarkers and molecular clock analyses highlight the difficulties in this field of research. Although phylogenomic analyses have provided promising glimpses into the early evolution of cyanobacteria, estimated divergence ages are often very uncertain, because of vague and insufficient tree-calibrations. Results of molecular clock analyses are intrinsically tied to these prior calibration points, hence improving calibrations will enable more precise divergence time estimations. Here we provide a review of previously described Precambrian microfossils, biomarkers and geochemical markers that inform upon the early evolution of cyanobacteria. Future research in micropalaeontology will require novel analyses and imaging techniques to improve taxonomic affiliation of many Precambrian microfossils. Consequently, a better understanding of early cyanobacterial evolution will not only allow for a more specific calibration of cyanobacterial and eubacterial phylogenies, but also provide new dates for the tree

Short sleep duration and dietary intake: epidemiologic evidence, mechanisms, and health implications

Science.gov (United States)

Links between short sleep duration and obesity, type 2 diabetes, hypertension, and cardiovascular disease may be mediated through changes in dietary intake. This review provides an overview of recent epidemiologic studies on the relations between habitual short sleep duration and dietary intake in a...

The covariant-evolution-operator method in bound-state QED

International Nuclear Information System (INIS)

Lindgren, Ingvar; Salomonson, Sten; Aasen, Bjoern

2004-01-01

The methods of quantum-electrodynamical (QED) calculations on bound atomic systems are reviewed with emphasis on the newly developed covariant-evolution-operator method. The aim is to compare that method with other available methods and also to point out possibilities to combine that with standard many-body perturbation theory (MBPT) in order to perform accurate numerical QED calculations, including quasi-degeneracy, also for light elements, where the electron correlation is relatively strong. As a background, the time-independent many-body perturbation theory (MBPT) is briefly reviewed, particularly the method with extended model space. Time-dependent perturbation theory is discussed in some detail, introducing the time-evolution operator and the Gell-Mann-Low relation, generalized to an arbitrary model space. Three methods of treating the bound-state QED problem are discussed. The standard S-matrix formulation, which is restricted to a degenerate model space, is discussed only briefly. Two methods applicable also to the quasi-degenerate problem are treated in more detail, the two-times Green's-function and the covariant-evolution-operator techniques. The treatment is concentrated on the latter technique, which has been developed more recently and which has not been discussed in more detail before. A comparison of the two-times Green's-function and the covariant-evolution-operator techniques, which have great similarities, is performed. In the appendix a simple procedure is derived for expressing the evolution-operator diagrams of arbitrary order. The possibilities of merging QED in the covariant evolution-operator formulation with MBPT in a systematic way is indicated. With such a technique it might be feasible to perform accurate QED calculations also on light elements, which is presently not possible with the techniques available

Towards short wavelengths FELs workshop

International Nuclear Information System (INIS)

Ben-Zvi, I.; Winick, H.

1993-01-01

This workshop was caged because of the growing perception in the FEL source community that recent advances have made it possible to extend FEL operation to wavelengths about two orders of magnitude shorter than the 240 nm that has been achieved to date. In addition short wavelength FELs offer the possibilities of extremely high peak power (several gigawatts) and very short pulses (of the order of 100 fs). Several groups in the USA are developing plans for such short wavelength FEL facilities. However, reviewers of these plans have pointed out that it would be highly desirable to first carry out proof-of-principle experiments at longer wavelengths to increase confidence that the shorter wavelength devices will indeed perform as calculated. The need for such experiments has now been broadly accepted by the FEL community. Such experiments were the main focus of this workshop as described in the following objectives distributed to attendees: (1) Define measurements needed to gain confidence that short wavelength FELs will perform as calculated. (2) List possible hardware that could be used to carry out these measurements in the near term. (3) Define a prioritized FEL physics experimental program and suggested timetable. (4) Form collaborative teams to carry out this program

Towards short wavelengths FELs workshop

Science.gov (United States)

Ben-Zvi, I.; Winick, H.

1993-11-01

This workshop was caged because of the growing perception in the FEL source community that recent advances have made it possible to extend FEL operation to wavelengths about two orders of magnitude shorter than the 240 nm that has been achieved to date. In addition short wavelength FEL's offer the possibilities of extremely high peak power (several gigawatts) and very short pulses (of the order of 100 fs). Several groups in the USA are developing plans for such short wavelength FEL facilities. However, reviewers of these plans have pointed out that it would be highly desirable to first carry out proof-of-principle experiments at longer wavelengths to increase confidence that the shorter wavelength devices will indeed perform as calculated. The need for such experiments has now been broadly accepted by the FEL community. Such experiments were the main focus of this workshop as described in the following objectives distributed to attendees: (1) Define measurements needed to gain confidence that short wavelength FEL's will perform as calculated. (2) List possible hardware that could be used to carry out these measurements in the near term. (3) Define a prioritized FEL physics experimental program and suggested timetable. (4) Form collaborative teams to carry out this program.

Scientific reference on the long time evolution of spent fuels; Referentiel scientifique sur l'evolution a long terme des combustibles uses

Energy Technology Data Exchange (ETDEWEB)

Ferry, C.; Poinssot, Ch.; Broudic, V.; Jegou, Ch.; Roudil, D.; Poulesquen, A.; Miserque, F. [CEA Saclay, Dept. de Physico-Chimie, 91 - Gif sur Yvette (France); Cappelaere, Ch. [CEA Saclay, Dept. des Materiaux pour le Nucleaire, 91 - Gif-sur-Yvette (France); Desgranges, L.; Garcia, Ph.; Piron, J.P. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d' Etudes des Combustibles; Lovera, P.; Marimbeau, P. [CEA Cadarache, 13 - Saint Paul lez Durance (France). Dept. d' Etudes des Reacteurs; Corbel, C. [CEA Saclay, Dept. de Recherche sur l' Etat Condense, les Atomes et les Molecules, 91 - Gif sur Yvette (France)

2005-03-15

This report is published in the framework of the 1991 French law for the nuclear waste management. The state of the art reported here concerns the long term evolution of spent fuel in the various environmental conditions corresponding to dry storage and geological disposal: closed system, air and water saturated medium. This review is based on the results of the french PRECCI project (Research Program on Long term Evolution of Spent Nuclear Fuel) and on literature data. (authors)

Knowledge Evolution in Distributed Geoscience Datasets and the Role of Semantic Technologies

Science.gov (United States)

Ma, X.

2014-12-01

Knowledge evolves in geoscience, and the evolution is reflected in datasets. In a context with distributed data sources, the evolution of knowledge may cause considerable challenges to data management and re-use. For example, a short news published in 2009 (Mascarelli, 2009) revealed the geoscience community's concern that the International Commission on Stratigraphy's change to the definition of Quaternary may bring heavy reworking of geologic maps. Now we are in the era of the World Wide Web, and geoscience knowledge is increasingly modeled and encoded in the form of ontologies and vocabularies by using semantic technologies. Accordingly, knowledge evolution leads to a consequence called ontology dynamics. Flouris et al. (2008) summarized 10 topics of general ontology changes/dynamics such as: ontology mapping, morphism, evolution, debugging and versioning, etc. Ontology dynamics makes impacts at several stages of a data life cycle and causes challenges, such as: the request for reworking of the extant data in a data center, semantic mismatch among data sources, differentiated understanding of a same piece of dataset between data providers and data users, as well as error propagation in cross-discipline data discovery and re-use (Ma et al., 2014). This presentation will analyze the best practices in the geoscience community so far and summarize a few recommendations to reduce the negative impacts of ontology dynamics in a data life cycle, including: communities of practice and collaboration on ontology and vocabulary building, link data records to standardized terms, and methods for (semi-)automatic reworking of datasets using semantic technologies. References: Flouris, G., Manakanatas, D., Kondylakis, H., Plexousakis, D., Antoniou, G., 2008. Ontology change: classification and survey. The Knowledge Engineering Review 23 (2), 117-152. Ma, X., Fox, P., Rozell, E., West, P., Zednik, S., 2014. Ontology dynamics in a data life cycle: Challenges and recommendations

The TALE face of Hox proteins in animal evolution.

Science.gov (United States)

Merabet, Samir; Galliot, Brigitte

2015-01-01

Hox genes are major regulators of embryonic development. One of their most conserved functions is to coordinate the formation of specific body structures along the anterior-posterior (AP) axis in Bilateria. This architectural role was at the basis of several morphological innovations across bilaterian evolution. In this review, we traced the origin of the Hox patterning system by considering the partnership with PBC and Meis proteins. PBC and Meis belong to the TALE-class of homeodomain-containing transcription factors and act as generic cofactors of Hox proteins for AP axis patterning in Bilateria. Recent data indicate that Hox proteins acquired the ability to interact with their TALE partners in the last common ancestor of Bilateria and Cnidaria. These interactions relied initially on a short peptide motif called hexapeptide (HX), which is present in Hox and non-Hox protein families. Remarkably, Hox proteins can also recruit the TALE cofactors by using specific PBC Interaction Motifs (SPIMs). We describe how a functional Hox/TALE patterning system emerged in eumetazoans through the acquisition of SPIMs. We anticipate that interaction flexibility could be found in other patterning systems, being at the heart of the astonishing morphological diversity observed in the animal kingdom.

Water location, piospheres and a review of evolution in African ...

African Journals Online (AJOL)

The main radiation of large mammalian herbivores in Africa took place in the Pliocene–Pleistocene, when a long-term trend towards aridification promoted grasslands and the diversification of ruminant grazers. Traditional models of this evolution identify habitat fragmentation in response to climate change as the primary ...

MNE R&D Subsidiary Mandates Evolution in Emerging Economies

DEFF Research Database (Denmark)

Schulzmann, David; Slepniov, Dmitrij

2017-01-01

The aim of this paper is to present the results of a systematic literature review (SLR) on the subject of Research and Development (R&D) subsidiary mandate evolution in emerging economies and to illustrate what triggers R&D mandate upgrade. The subject of R&D mandates is of crucial importance to ...... on subsidiary evolution in general and particularly in emerging markets. From a practical perspective, a better-integrated framework can provide guidance to businesses in emerging economies on how to start and successfully upgrade their R&D activities.......The aim of this paper is to present the results of a systematic literature review (SLR) on the subject of Research and Development (R&D) subsidiary mandate evolution in emerging economies and to illustrate what triggers R&D mandate upgrade. The subject of R&D mandates is of crucial importance...... to many multinational enterprises (MNEs) striving to utilize the potential of their foreign operations towards higher-value-added activities. While developed economies have long been a destination for R&D activities, emerging economies are increasingly recognized for their innovation potential. Previous...

Tracking Alu evolution in New World primates

Directory of Open Access Journals (Sweden)

Batzer Mark A

2005-10-01

Full Text Available Abstract Background Alu elements are Short INterspersed Elements (SINEs in primate genomes that have proven useful as markers for studying genome evolution, population biology and phylogenetics. Most of these applications, however, have been limited to humans and their nearest relatives, chimpanzees. In an effort to expand our understanding of Alu sequence evolution and to increase the applicability of these markers to non-human primate biology, we have analyzed available Alu sequences for loci specific to platyrrhine (New World primates. Results Branching patterns along an Alu sequence phylogeny indicate three major classes of platyrrhine-specific Alu sequences. Sequence comparisons further reveal at least three New World monkey-specific subfamilies; AluTa7, AluTa10, and AluTa15. Two of these subfamilies appear to be derived from a gene conversion event that has produced a recently active fusion of AluSc- and AluSp-type elements. This is a novel mode of origin for new Alu subfamilies. Conclusion The use of Alu elements as genetic markers in studies of genome evolution, phylogenetics, and population biology has been very productive when applied to humans. The characterization of these three new Alu subfamilies not only increases our understanding of Alu sequence evolution in primates, but also opens the door to the application of these genetic markers outside the hominid lineage.

Hyperphagic short stature: A case report and review of literature

Directory of Open Access Journals (Sweden)

Varsha S Jagtap

2012-01-01

Full Text Available A 5½-year-old adopted girl was referred to us in view of short stature. After ruling out systemic illness, she was evaluated for growth hormone deficiency (GHD by stimulation tests. The peak value was 3.47 ng/ml. She was then started on growth hormone (GH. At the end of 6 months of GH therapy, her height velocity was only 3 cm/year. There was a lack of attachment between the mother and the child. She had history of hyperphagia, stealing, and hoarding food. Psychiatry consultation confirmed that the child had appetite disorder, and hence was diagnosed as hyperphagic short stature (HSS. The girl and her parents are undergoing psychiatric therapy for the same. Psychosocial dwarfism seems to originate from serious disturbances in the mother-child relationship. These children mimic patients with GHD, but have poor response to GH therapy. This case underscores the importance of social environment in the growth of the individual.

Hyperphagic short stature: A case report and review of literature

Science.gov (United States)

Jagtap, Varsha S.; Sarathi, Vijaya; Lila, Anurag R.; Bukan, Amol P.; Bandgar, Tushar; Menon, Padmavathy; Shah, Nalini S.

2012-01-01

A 5½-year-old adopted girl was referred to us in view of short stature. After ruling out systemic illness, she was evaluated for growth hormone deficiency (GHD) by stimulation tests. The peak value was 3.47 ng/ml. She was then started on growth hormone (GH). At the end of 6 months of GH therapy, her height velocity was only 3 cm/year. There was a lack of attachment between the mother and the child. She had history of hyperphagia, stealing, and hoarding food. Psychiatry consultation confirmed that the child had appetite disorder, and hence was diagnosed as hyperphagic short stature (HSS). The girl and her parents are undergoing psychiatric therapy for the same. Psychosocial dwarfism seems to originate from serious disturbances in the mother–child relationship. These children mimic patients with GHD, but have poor response to GH therapy. This case underscores the importance of social environment in the growth of the individual. PMID:22837929

Tidal instability in exoplanetary systems evolution

Directory of Open Access Journals (Sweden)

Le Gal P.

2011-02-01

Full Text Available A new element is proposed to play a role in the evolution of extrasolar planetary systems: the tidal (or elliptical instability. It comes from a parametric resonance and takes place in any rotating fluid whose streamlines are (even slightly elliptically deformed. Based on theoretical, experimental and numerical works, we estimate the growth rate of the instability for hot-jupiter systems, when the rotation period of the star is known. We present the physical process, its application to stars, and preliminary results obtained on a few dozen systems, summarized in the form of a stability diagram. Most of the systems are trapped in the so-called "forbidden zone", where the instability cannot grow. In some systems, the tidal instability is able to grow, at short timescales compared to the system evolution. Implications are discussed in the framework of misaligned transiting systems, as the rotational axis of the star would be unstable in systems where this elliptical instability grows.

[Swine influenza virus: evolution mechanism and epidemic characterization--a review].

Science.gov (United States)

Qi, Xian; Lu, Chengping

2009-09-01

Pigs may play an important role in the evolution and ecology of influenza A virus. The tracheal epithelium of pigs contain both SA alpha 2,6 Gal and SA alpha 2,3 Gal receptors and can be infected with swine, human and avian viruses, therefore, pigs have been considered as an intermediate host for the adaptation of avian influenza viruses to humans or as mixing vessels for the generation of genetically reassortant viruses. Evolution patterns among swine influenza viruses including evolution of host adaptation, antigenic drift and genetic reassortment, and the latter is the main one. Unlike human influenza viruses, swine viruses have different epizootiological patterns in different areas of world, which is enzootic and geographic dependence. Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2, and these include classical swine H1N1, avian-like H1N1, human-like H3N2, reassortant H3N2 and various genotype H1N2 viruses. In Europe, North America and China, influenza A viruses circulating in pigs are distinct in the genetic characteristics and genetic sources. Since 1979, three subtypes, avian-like H1N1, reassortant H1N2 and H3N2 viruses, have been co-circulating in European swine. Before 1998, classical H1N1 viruses were the exclusive cause of swine influenza in North America. However, after that, three triple-reassortant H1N2, H3N2 and H1N1 viruses with genes of human, swine and avian virus began to emerge in pigs. Genetically, the pandemic viruses emerging in human, so called influenza A (H1N1) viruses, contain genes from both Europe and North American SIV lineages. SIV is not the same as Europe and the United States in the prevalence and genetic background in China, mainly classical swine H1N1 and human-like H3N2 type virus. However, in recent years, SIV from Europe and North America have been introduced into Chinese pig herds, so more attention should be given on the evolutionary of SIV in China

Self-amplified spontaneous emission for short wavelength coherent radiation

International Nuclear Information System (INIS)

Kim, K.J.; Xie, M.

1992-09-01

We review the recent progress in our understanding of the self-amplified spontaneous emission (SASE), emphasizing the application to short wavelength generation. Simple formulae are given for the start-up, exponential gain and the saturation of SASE. Accelerator technologies producing high brightness electron beams required for short wavelength SASE are discussed. An example utilizing electron beams from a photocathode-linac system to produce 4nm SASE in the multigigawatt range is presented

Gravitational instability, evolution of galaxies and star formation

International Nuclear Information System (INIS)

Palous, J.

1979-01-01

The gravitational collapse is the key to the theories of galaxy and star formation. The observations, showing intrinsic differences between elliptical and spiral galaxies, guide our fundamental conceptions on the formation and evolution of systems in question. Stars in elliptical galaxies and in spherical components of spiral galaxies were formed in a short period of time during early phases of protogalactic collapse, at a time of violent star formation. The disc-like components of spiral galaxies, however, were built gradually in the course of galactic evolution. Star formation in elliptical galaxies is described by the collision model of interstellar clouds, while star formation in discs is characterised by several processes: the expansion of HII regions, the expansion of supernovae remnants and the shock wave related to the presence of the spiral structure. (author)

A cultural evolution approach to digital media

NARCIS (Netherlands)

Acerbi, A.

2016-01-01

Digital media have today an enormous diffusion, and their influence on the behaviour of a vast part of the human population can hardly be underestimated. In this review I propose that cultural evolution theory, including both a sophisticated view of human behaviour and a methodological attitude to

Short-term mechanical circulatory support as a bridge to durable left ventricular assist device implantation in refractory cardiogenic shock: a systematic review and meta-analysis.

Science.gov (United States)

den Uil, Corstiaan A; Akin, Sakir; Jewbali, Lucia S; Dos Reis Miranda, Dinis; Brugts, Jasper J; Constantinescu, Alina A; Kappetein, Arie Pieter; Caliskan, Kadir

2017-07-01

Short-term mechanical circulatory support (MCS) is increasingly used as a bridge to decision in patients with refractory cardiogenic shock. Subsequently, these patients might be bridged to durable MCS either as a bridge to candidacy/transplantation, or as destination therapy. The aim of this study was to review support duration and clinical outcome of short-term MCS in cardiogenic shock, and to analyse application of this technology as a bridge to long-term cardiac support (left ventricular assist device, LVAD) from 2006 till June 2016. Using Cochrane Register of Trials, Embase and Medline, a systematic review was performed on patients with cardiogenic shock from acute myocardial infarction, end-stage cardiomyopathy, or acute myocarditis, receiving short-term MCS. Studies on periprocedural, post-cardiotomy and cardiopulmonary resuscitation support were excluded. Thirty-nine studies, mainly registries of heterogeneous patient populations (n = 4151 patients), were identified. Depending on the device used (intra-aortic balloon pump, TandemHeart, Impella 2.5, Impella 5.0, CentriMag and peripheral veno-arterial extracorporeal membrane oxygenation), mean support duration was (range) 1.6-25 days and the mean proportion of short-term MCS patients discharged was (range) 45-66%. The mean proportion of bridge to durable LVAD was (range) 3-30%. Bridge to durable LVAD was most frequently performed in patients with end-stage cardiomyopathy (22 [12-35]%). We conclude that temporary MCS can be used to bridge patients with cardiogenic shock towards durable LVAD. Clinicians are encouraged to share their results in a large multicentre registry in order to investigate optimal device selection and best duration of support. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Early evolution without a tree of life

Directory of Open Access Journals (Sweden)

Martin William F

2011-06-01

Full Text Available Abstract Life is a chemical reaction. Three major transitions in early evolution are considered without recourse to a tree of life. The origin of prokaryotes required a steady supply of energy and electrons, probably in the form of molecular hydrogen stemming from serpentinization. Microbial genome evolution is not a treelike process because of lateral gene transfer and the endosymbiotic origins of organelles. The lack of true intermediates in the prokaryote-to-eukaryote transition has a bioenergetic cause. This article was reviewed by Dan Graur, W. Ford Doolittle, Eugene V. Koonin and Christophe Malaterre.

The evolution, morphology and development of fern leaves

Directory of Open Access Journals (Sweden)

Alejandra eVasco

2013-09-01

Full Text Available Leaves are lateral determinate structures formed in a predictable sequence (phyllotaxy on the flanks of an indeterminate shoot apical meristem. The origin and evolution of leaves in vascular plants has been widely debated. Being the main conspicuous organ of nearl all vascular plants and often easy to recognize as such, it seems surprising that leaves have had multiple origins. For decades, morphologists, anatomists, paleobotanists, and systematists have contributed data to this debate. More recently, molecular genetic studies have provided insight into leaf evolution and development mainly within angiosperms and, to a lesser extent, lycophytes. There has been recent interest in extending leaf evolutionary developmental studies to other species and lineages, particularly in lycophytes and ferns. Therefore, a review of fern leaf morphology, evolution and development is timely. Here we discuss the theories of leaf evolution in ferns, morphology and diversity of fern leaves, and experimental results of fern leaf development. We summarize what is known about the molecular genetics of fern leaf development and what future studies might tell us about the evolution of fern leaf development.

Horizontal transfer of short and degraded DNA has evolutionary implications for microbes and eukaryotic sexual reproduction.

Science.gov (United States)

Overballe-Petersen, Søren; Willerslev, Eske

2014-10-01

Horizontal gene transfer in the form of long DNA fragments has changed our view of bacterial evolution. Recently, we discovered that such processes may also occur with the massive amounts of short and damaged DNA in the environment, and even with truly ancient DNA. Although it presently remains unclear how often it takes place in nature, horizontal gene transfer of short and damaged DNA opens up the possibility for genetic exchange across distinct species in both time and space. In this essay, we speculate on the potential evolutionary consequences of this phenomenon. We argue that it may challenge basic assumptions in evolutionary theory; that it may have distant origins in life's history; and that horizontal gene transfer should be viewed as an evolutionary strategy not only preceding but causally underpinning the evolution of sexual reproduction. © 2014 The Authors. BioEssays Published by WILEY Periodicals, Inc.

The evolution of lycopsid rooting structures: conservatism and disparity.

Science.gov (United States)

Hetherington, Alexander J; Dolan, Liam

2017-07-01

Contents 538 I. 538 II. 539 III. 541 IV. 542 543 References 543 SUMMARY: The evolution of rooting structures was a crucial event in Earth's history, increasing the ability of plants to extract water, mine for nutrients and anchor above-ground shoot systems. Fossil evidence indicates that roots evolved at least twice among vascular plants, in the euphyllophytes and independently in the lycophytes. Here, we review the anatomy and evolution of lycopsid rooting structures. Highlighting recent discoveries made with fossils we suggest that the evolution of lycopsid rooting structures displays two contrasting patterns - conservatism and disparity. The structures termed roots have remained structurally similar despite hundreds of millions of years of evolution - an example of remarkable conservatism. By contrast, and over the same time period, the organs that give rise to roots have diversified, resulting in the evolution of numerous novel and disparate organs. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Temporal evolution of plasma density in femtosecond light filaments

International Nuclear Information System (INIS)

Wang Haitao; Fan Chengyu; Shen Hong; Qiao Chunhong; Zhang Jinghui; Zhang Pengfei; Ma Huimin; Xu Huiling

2012-01-01

By using a legible and comprehensive physical model describing the generation and evolvement of ion densities in the plasma channel induced by intense femtosecond laser pulse, the work studied the temporal evolution of the plasma densities in femtosecond light filaments. It shows that the contribution of the ionization of oxygen and nitrogen molecules to the total electron densities varies much for different laser pulse shapes, and the pulse shapes have more effects on the lifetime of the higher density plasma. It is necessary to control the pulse shape for efficient using of the plasma channel. Pulses of long duration and short wavelength can obtain a plasma channel with higher electron density, but the channel lifetime thoroughly depends on the later evolution of the self-guided channel. (authors)

Secular Evolution in Disk Galaxies

Science.gov (United States)

Kormendy, John

2013-10-01

Self-gravitating systems evolve toward the most tightly bound configuration that is reachable via the evolution processes that are available to them. They do this by spreading -- the inner parts shrink while the outer parts expand -- provided that some physical process efficiently transports energy or angular momentum outward. The reason is that self-gravitating systems have negative specific heats. As a result, the evolution of stars, star clusters, protostellar and protoplanetary disks, black hole accretion disks and galaxy disks are fundamentally similar. How evolution proceeds then depends on the evolution processes that are available to each kind of self-gravitating system. These processes and their consequences for galaxy disks are the subjects of my lectures and of this Canary Islands Winter School. I begin with a review of the formation, growth and death of bars. Then I review the slow (`secular') rearrangement of energy, angular momentum, and mass that results from interactions between stars or gas clouds and collective phenomena such as bars, oval disks, spiral structure and triaxial dark haloes. The `existence-proof' phase of this work is largely over: we have a good heuristic understanding of how nonaxisymmetric structures rearrange disk gas into outer rings, inner rings and stuff dumped onto the centre. The results of simulations correspond closely to the morphology of barred and oval galaxies. Gas that is transported to small radii reaches high densities. Observations confirm that many barred and oval galaxies have dense central concentrations of gas and star formation. The result is to grow, on timescales of a few Gyr, dense central components that are frequently mistaken for classical (elliptical-galaxy-like) bulges but that were grown slowly out of the disk (not made rapidly by major mergers). The resulting picture of secular galaxy evolution accounts for the richness observed in galaxy structure. We can distinguish between classical and pseudo

Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

International Nuclear Information System (INIS)

Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H.Y.; Fu, B.Q.; Li, M.; Liu, W.

2013-01-01

Highlights: ► Recrystallization temperature of a rolled W was ∼2480 °C under applied HHF loads. ► Fine grains were obtained under HHF loads with appropriate short pulse length. ► With increasing pulse length, the recrystallized grains significantly grew larger. ► A linear relationship between ln d and 1/T max was found. ► Activation energy for grain growth in T evolution up to T max in 1.5 s was obtained. -- Abstract: Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m 2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/T max ) was found and accordingly the activation energy for grain growth in temperature evolution up to T max in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads

Audit of long-term and short-term liabilities

Directory of Open Access Journals (Sweden)

Korinko M.D.

2017-03-01

Full Text Available The article determines the importance of long-term and short-term liabilities for the management of financial and material resources of an enterprise. It reviews the aim, objects and information generators for realization of audit of short-term and long-term obligations. The organizing and methodical providing of audit of long-term and short-term liabilities of an enterprise are generalized. The authors distinguish the stages of realization of audit of long-term and short-term liabilities, the aim of audit on each of the presented stages, and recommend methodical techniques. It is fixed that it is necessary to conduct the estimation of the systems of internal control and record-keeping of an enterprise by implementation of public accountant procedures for determination of volume and maintenance of selection realization. After estimating the indicated systems, a public accountant determines the methodology for realization of public accountant verification of long-term and short-term liabilities. The analytical procedures that public accountants are expedient to use for realization of audit of short-term and long-term obligations are determined. The authors suggest the classification of the educed defects on the results of the conducted public accountant verification of short-term and long-term obligations.

Geochemical modelling of groundwater evolution using chemical equilibrium codes

International Nuclear Information System (INIS)

Pitkaenen, P.; Pirhonen, V.

1991-01-01

Geochemical equilibrium codes are a modern tool in studying interaction between groundwater and solid phases. The most common used programs and application subjects are shortly presented in this article. The main emphasis is laid on the approach method of using calculated results in evaluating groundwater evolution in hydrogeological system. At present in geochemical equilibrium modelling also kinetic as well as hydrologic constrains along a flow path are taken into consideration

Measurement of short-lived particles at PETRA

International Nuclear Information System (INIS)

Saxon, D.H.

1987-04-01

The contribution of PETRA to the measurement of short-lived particles is reviewed with discussion of the detectors and analysis techniques. New results are presented on lifetimes of identified particles and the systematics of b-life measurement outlined. The first application of vertex-tagging to flavour separation is described. (author)

Results of Evolution Supervised by Genetic Algorithms

Directory of Open Access Journals (Sweden)

Lorentz JÄNTSCHI

2010-09-01

Full Text Available The efficiency of a genetic algorithm is frequently assessed using a series of operators of evolution like crossover operators, mutation operators or other dynamic parameters. The present paper aimed to review the main results of evolution supervised by genetic algorithms used to identify solutions to agricultural and horticultural hard problems and to discuss the results of using a genetic algorithms on structure-activity relationships in terms of behavior of evolution supervised by genetic algorithms. A genetic algorithm had been developed and implemented in order to identify the optimal solution in term of estimation power of a multiple linear regression approach for structure-activity relationships. Three survival and three selection strategies (proportional, deterministic and tournament were investigated in order to identify the best survival-selection strategy able to lead to the model with higher estimation power. The Molecular Descriptors Family for structure characterization of a sample of 206 polychlorinated biphenyls with measured octanol-water partition coefficients was used as case study. Evolution using different selection and survival strategies proved to create populations of genotypes living in the evolution space with different diversity and variability. Under a series of criteria of comparisons these populations proved to be grouped and the groups were showed to be statistically different one to each other. The conclusions about genetic algorithm evolution according to a number of criteria were also highlighted.

Web 1.0 to Web 3.0 Evolution: Reviewing the Impacts on Tourism Development and Opportunities

Science.gov (United States)

Eftekhari, M. Hossein; Barzegar, Zeynab; Isaai, M. T.

The most important event following the establishmenet of the Internet network was the Web introduced by Tim Berners-Lee. Websites give their owners features that allow sharing with which they can publish their content with users and visitors. In the last 5 years, we have seen some changes in the use of web. Users want to participate in content sharing and they like to interact with each other. This is known as Web 2.0. In the last year, Web 2.0 has reached maturity and now we need a smart web which will be accordingly be called Web 3.0. Web 3.0 is based on semantic web definition. Changing the way of using the web has had a clear impact on E-Tourism and its development and also on business models. In this paper, we review the definitions and describe the impacts of web evolution on E-Tourism.

SITE WIDE SHORT CIRCUIT STUDY ASSESSMENT

International Nuclear Information System (INIS)

CARRATT, R.T.

2004-01-01

The Department of Energy requested that Fluor Hanford develop a plan to update the electrical distribution studies for FH managed facilities. Toward this end, an assessment of FH's nuclear facilities was performed to determine whether a current short circuit study of the facility electrical distribution system exists, and the status of such study. This report presents the methodology and results of that assessment. The assessment identified 29 relevant facilities. Of these, a short circuit study could not be identified for 15 facilities. A short circuit study was found to exist for fourteen facilities, however, of these 14, four were not released into a controlled document system, and two were not performed for the entire electrical distribution system. It is recommended that for four of the facilities no further action is required based upon the limited nature of the existing electrical system, or as in the case of PFP, the status of the existing short circuit study was determined adequate. For the majority of the facilities without a short circuit study, it is recommended that one is performed, and released into a controlled document system. Two facilities require further evaluation due to missing or conflicting documentation. For the remainder of the facilities, the recommendations are to review and revise as appropriate the existing study, and release into a controlled document system. A summation of the recommendations is presented

Geometric differential evolution for combinatorial and programs spaces.

Science.gov (United States)

Moraglio, A; Togelius, J; Silva, S

2013-01-01

Geometric differential evolution (GDE) is a recently introduced formal generalization of traditional differential evolution (DE) that can be used to derive specific differential evolution algorithms for both continuous and combinatorial spaces retaining the same geometric interpretation of the dynamics of the DE search across representations. In this article, we first review the theory behind the GDE algorithm, then, we use this framework to formally derive specific GDE for search spaces associated with binary strings, permutations, vectors of permutations and genetic programs. The resulting algorithms are representation-specific differential evolution algorithms searching the target spaces by acting directly on their underlying representations. We present experimental results for each of the new algorithms on a number of well-known problems comprising NK-landscapes, TSP, and Sudoku, for binary strings, permutations, and vectors of permutations. We also present results for the regression, artificial ant, parity, and multiplexer problems within the genetic programming domain. Experiments show that overall the new DE algorithms are competitive with well-tuned standard search algorithms.

Quantitative Modeling of Landscape Evolution, Treatise on Geomorphology

NARCIS (Netherlands)

Temme, A.J.A.M.; Schoorl, J.M.; Claessens, L.F.G.; Veldkamp, A.; Shroder, F.S.

2013-01-01

This chapter reviews quantitative modeling of landscape evolution – which means that not just model studies but also modeling concepts are discussed. Quantitative modeling is contrasted with conceptual or physical modeling, and four categories of model studies are presented. Procedural studies focus

Neutral and Non-Neutral Evolution of Duplicated Genes with Gene Conversion

Directory of Open Access Journals (Sweden)

Jeffrey A. Fawcett

2011-02-01

Full Text Available Gene conversion is one of the major mutational mechanisms involved in the DNA sequence evolution of duplicated genes. It contributes to create unique patters of DNA polymorphism within species and divergence between species. A typical pattern is so-called concerted evolution, in which the divergence between duplicates is maintained low for a long time because of frequent exchanges of DNA fragments. In addition, gene conversion affects the DNA evolution of duplicates in various ways especially when selection operates. Here, we review theoretical models to understand the evolution of duplicates in both neutral and non-neutral cases. We also explain how these theories contribute to interpreting real polymorphism and divergence data by using some intriguing examples.

Evolution of acoustically vaporized microdroplets in gas embolotherapy

KAUST Repository

Qamar, Adnan; Wong, ZhengZheng; Fowlkes, Brian Brian; Bull, Joseph L.

2012-01-01

Acoustic vaporization dynamics of a superheated dodecafluoropentane (DDFP) microdroplet inside a microtube and the resulting bubble evolution is investigated in the present work. This work is motivated by a developmental gas embolotherapy technique that is intended to treat cancers by infarcting tumors using gas bubbles. A combined theoretical and computational approach is utilized and compared with the experiments to understand the evolution process and to estimate the resulting stress distribution associated with vaporization event. The transient bubble growth is first studied by ultra-high speed imaging and then theoretical and computational modeling is used to predict the entire bubble evolution process. The evolution process consists of three regimes: an initial linear rapid spherical growth followed by a linear compressed oval shaped growth and finally a slow asymptotic nonlinear spherical bubble growth. Although the droplets are small compared to the tube diameter, the bubble evolution is influenced by the tube wall. The final bubble radius is found to scale linearly with the initial droplet radius and is approximately five times the initial droplet radius. A short pressure pulse with amplitude almost twice as that of ambient conditions is observed. The width of this pressure pulse increases with increasing droplet size whereas the amplitude is weakly dependent. Although the rise in shear stress along the tube wall is found to be under peak physiological limits, the shear stress amplitude is found to be more prominently influenced by the initial droplet size. The role of viscous dissipation along the tube wall and ambient bulk fluid pressure is found to be significant in bubble evolution dynamics. © 2012 American Society of Mechanical Engineers.

Comment on "Defocusing complex short-pulse equation and its multi-dark-soliton solution"

Science.gov (United States)

Youssoufa, Saliou; Kuetche, Victor K.; Kofane, Timoleon C.

2017-08-01

In their recent paper, Feng et al. [Phys. Rev. E 93, 052227 (2016), 10.1103/PhysRevE.93.052227] proposed a complex short-pulse equation of both focusing and defocusing types. They studied in detail the defocusing case and derived its multi-dark-soliton solutions. Nonetheless, from a physical viewpoint in order to better and deeply understand their genuine implications, we find it useful to provide a real and proper background for the derivation of the previous evolution system while showing that the expression of the nonlinear electric polarization the above authors used in their scheme is not suitable for getting the defocusing complex short-pulse equation.

Dental Calculus and the Evolution of the Human Oral Microbiome.

Science.gov (United States)

Warinner, Christina

2016-07-01

Characterizing the evolution of the oral microbiome is a challenging, but increasingly feasible, task. Recently, dental calculus has been shown to preserve ancient biomolecules from the oral microbiota, host tissues and diet for tens of thousands of years. As such, it provides a unique window into the ancestral oral microbiome. This article reviews recent advancements in ancient dental calculus research and emerging insights into the evolution and ecology of the human oral microbiome.

Short communication: Multi-scale topographic anisotropy patterns on a Barrier Island

Science.gov (United States)

Houser, Chris; Bishop, Michael; Wernette, Phil

2017-11-01

Barrier islands exhibit a range of landforms that reflect the complex and varied combination of coastal and aeolian processes realized over the evolution of the island. A detailed analysis of the topography can be used to describe the evolution of a barrier island and provide insight on how it may be affected by a change in sea level, storm activity and wind exposure patterns. Topographic anisotropy, or the directional dependence of relief of landforms, can be used to determine the relative importance of different processes to island evolution at a range of scales. This short communication describes the use of scale-dependent topographic anisotropy to characterize the structure of Santa Rosa Island in northwest Florida. Scale-dependent topographic relief and asymmetry were assessed from a LiDAR-derived DEM from May 2004, a few months before the island experienced widespread erosion and overwash during Hurricane Ivan. This application demonstrates how anisotropy can be used to identify unique scale-dependent structures that can be used to interpret the evolution of this barrier island. Results of this preliminary study further highlight the potential of using topographic anisotropy to controls on barrier island response and recovery to storms as well as island resiliency with sea level rise and storm activity.

Can the experimental evolution programme help us elucidate the genetic basis of adaptation in nature?

DEFF Research Database (Denmark)

Bailey, Susan; Bataillon, Thomas

2015-01-01

and continue to play an important role in shaping adaptive evolution in the natural world. Further to this, experimental evolution studies allow for tests of theories that may be difficult or impossible to test in natural populations for logistical and methodological reasons and can even generate new insights......, suggesting further refinement of existing theories. However, as experimental evolution studies often take place in a very particular set of controlled conditions – that is simple environments, a small range of usually asexual species, relatively short timescales – the question remains as to how applicable...... natural population studies. We finish by making suggestions for future work in particular a need for natural population genomic time series data, as well as the necessity for studies that combine both experimental evolution and natural population approaches....

Size evolution of ultrafine particles: Differential signatures of normal and episodic events

International Nuclear Information System (INIS)

Joshi, Manish; Khan, Arshad; Anand, S.; Sapra, B.K.

2016-01-01

The effect of fireworks on the aerosol number characteristics of atmosphere was studied for an urban mega city. Measurements were made at 50 m height to assess the local changes around the festival days. Apart from the increase in total number concentration and characteristic accumulation mode, short-term increase of ultrafine particle concentration was noted. Total number concentration varies an order of magnitude during the measurement period in which peak occurs at a frequency of approximately one per day. On integral scale, it seems not possible to distinguish an episodic (e.g. firework bursting induced aerosol emission) and a normal (ambient atmospheric changes) event. However these events could be differentiated on the basis of size evolution analysis around number concentration peaks. The results are discussed relative to past studies and inferences are drawn towards aerosol signatures of firework bursting. The short-term burst in ultrafine particle concentration can pose an inhalation hazard. - Highlights: • Effect of firework emissions on atmospheric aerosol characteristics was studied. • Significant increase in ultrafine particle concentration was observed during firework bursting. • Size distribution evolution analysis of number concentration peaks has been performed. • Differential signatures of normal and episodic event were noted. - Notable increase in ultrafine particle concentration during firework bursting was seen. Normal and episodic event could be differentiated on the basis of size evolution analysis.

Adaptive evolution of transcription factor binding sites

Directory of Open Access Journals (Sweden)

Berg Johannes

2004-10-01

Full Text Available Abstract Background The regulation of a gene depends on the binding of transcription factors to specific sites located in the regulatory region of the gene. The generation of these binding sites and of cooperativity between them are essential building blocks in the evolution of complex regulatory networks. We study a theoretical model for the sequence evolution of binding sites by point mutations. The approach is based on biophysical models for the binding of transcription factors to DNA. Hence we derive empirically grounded fitness landscapes, which enter a population genetics model including mutations, genetic drift, and selection. Results We show that the selection for factor binding generically leads to specific correlations between nucleotide frequencies at different positions of a binding site. We demonstrate the possibility of rapid adaptive evolution generating a new binding site for a given transcription factor by point mutations. The evolutionary time required is estimated in terms of the neutral (background mutation rate, the selection coefficient, and the effective population size. Conclusions The efficiency of binding site formation is seen to depend on two joint conditions: the binding site motif must be short enough and the promoter region must be long enough. These constraints on promoter architecture are indeed seen in eukaryotic systems. Furthermore, we analyse the adaptive evolution of genetic switches and of signal integration through binding cooperativity between different sites. Experimental tests of this picture involving the statistics of polymorphisms and phylogenies of sites are discussed.

SINEs, evolution and genome structure in the opossum.

Science.gov (United States)

Gu, Wanjun; Ray, David A; Walker, Jerilyn A; Barnes, Erin W; Gentles, Andrew J; Samollow, Paul B; Jurka, Jerzy; Batzer, Mark A; Pollock, David D

2007-07-01

Short INterspersed Elements (SINEs) are non-autonomous retrotransposons, usually between 100 and 500 base pairs (bp) in length, which are ubiquitous components of eukaryotic genomes. Their activity, distribution, and evolution can be highly informative on genomic structure and evolutionary processes. To determine recent activity, we amplified more than one hundred SINE1 loci in a panel of 43 M. domestica individuals derived from five diverse geographic locations. The SINE1 family has expanded recently enough that many loci were polymorphic, and the SINE1 insertion-based genetic distances among populations reflected geographic distance. Genome-wide comparisons of SINE1 densities and GC content revealed that high SINE1 density is associated with high GC content in a few long and many short spans. Young SINE1s, whether fixed or polymorphic, showed an unbiased GC content preference for insertion, indicating that the GC preference accumulates over long time periods, possibly in periodic bursts. SINE1 evolution is thus broadly similar to human Alu evolution, although it has an independent origin. High GC content adjacent to SINE1s is strongly correlated with bias towards higher AT to GC substitutions and lower GC to AT substitutions. This is consistent with biased gene conversion, and also indicates that like chickens, but unlike eutherian mammals, GC content heterogeneity (isochore structure) is reinforced by substitution processes in the M. domestica genome. Nevertheless, both high and low GC content regions are apparently headed towards lower GC content equilibria, possibly due to a relative shift to lower recombination rates in the recent Monodelphis ancestral lineage. Like eutherians, metatherian (marsupial) mammals have evolved high CpG substitution rates, but this is apparently a convergence in process rather than a shared ancestral state.

Classification and Comparison of Architecture Evolution Reuse Knowledge - A Systematic Review

DEFF Research Database (Denmark)

Ahmad, Aakash; Jamshidi, Pooyan; Pahl, Claus

2014-01-01

patterns (34% of selected studies) represent a predominant solution, followed by evolution styles (25%) and adaptation strategies and policies (22%) to enable application of reuse knowledge. Empirical methods for acquisition of reuse knowledge represent 19% including pattern discovery, configuration...

Lethal neonatal short-limbed dwarfism

International Nuclear Information System (INIS)

Kim, Ok Hwa; Yim, Chung Ik; Bahk, Yong Whee

1986-01-01

We have detailed our experiences on 6 cases of neonatal lethal short-limbed dwarfism and reviewed the articles. They include, achondrogenesis, thanatophoric dysplasia, asphyxiating thoracic dysplasia, osteogenesis imperfect a congenita, and hypophosphatasia lethals. Five babies were born alive but died soon after birth and one was a stillbirth. The main cause of failure to thrive was respiratory insufficiency. Each case was having quite characteristic radiologic findings, even if the general appearances were similar to the achondroplasts clinically. Precise diagnosis is very important for genetic counselling of the parents and alarm to them the possibility of bone dysplasias to the next offsprings. For this purpose, the radiologists play major role for the correct diagnosis. We stress that when the baby is born with short-limbed dwarfism, whole body radiogram should be taken including lateral view and postmortem radiogram is also very precious.

Lethal neonatal short-limbed dwarfism

Energy Technology Data Exchange (ETDEWEB)

Kim, Ok Hwa; Yim, Chung Ik; Bahk, Yong Whee [Catholic Medical College, Seoul (Korea, Republic of)

1986-02-15

We have detailed our experiences on 6 cases of neonatal lethal short-limbed dwarfism and reviewed the articles. They include, achondrogenesis, thanatophoric dysplasia, asphyxiating thoracic dysplasia, osteogenesis imperfect a congenita, and hypophosphatasia lethals. Five babies were born alive but died soon after birth and one was a stillbirth. The main cause of failure to thrive was respiratory insufficiency. Each case was having quite characteristic radiologic findings, even if the general appearances were similar to the achondroplasts clinically. Precise diagnosis is very important for genetic counselling of the parents and alarm to them the possibility of bone dysplasias to the next offsprings. For this purpose, the radiologists play major role for the correct diagnosis. We stress that when the baby is born with short-limbed dwarfism, whole body radiogram should be taken including lateral view and postmortem radiogram is also very precious.

Evolution of filament barbs.

Science.gov (United States)

Liu, R.; Xu, Y.; Wang, H.

We present a selected few cases in which the sense of chirality of filament barbs changed within periods as short as hours. We investigate in detail a quiescent filament on 2003 September 10 and 11. Of its four barbs displaying such changes, only one overlays a small polarity inversion line inside the EUV filament channel (EFC). No magnetic elements with magnitude above the noise level were detected at the endpoints of all barbs. In particular, a pair of barbs first approached toward, and then departed from, each other in Halpha , with the barb endpoints migrating as far as ˜ 10 arcsec. We conclude that the evolution of the barbs was driven by flux emergence and cancellation of small bipolar units at the EFC border.

Origin, development, and evolution of butterfly eyespots.

Science.gov (United States)

Monteiro, Antónia

2015-01-07

This article reviews the latest developments in our understanding of the origin, development, and evolution of nymphalid butterfly eyespots. Recent contributions to this field include insights into the evolutionary and developmental origin of eyespots and their ancestral deployment on the wing, the evolution of eyespot number and eyespot sexual dimorphism, and the identification of genes affecting eyespot development and black pigmentation. I also compare features of old and more recently proposed models of eyespot development and propose a schematic for the genetic regulatory architecture of eyespots. Using this schematic I propose two hypotheses for why we observe limits to morphological diversity across these serially homologous traits.

Statistical mechanics of neocortical interactions: Constraints on 40-Hz models of short-term memory

Science.gov (United States)

Ingber, Lester

1995-10-01

Calculations presented in L. Ingber and P.L. Nunez, Phys. Rev. E 51, 5074 (1995) detailed the evolution of short-term memory in the neocortex, supporting the empirical 7+/-2 rule of constraints on the capacity of neocortical processing. These results are given further support when other recent models of 40-Hz subcycles of low-frequency oscillations are considered.

The Evolution of Software in High Energy Physics

International Nuclear Information System (INIS)

Brun, René

2012-01-01

The paper reviews the evolution of the software in High Energy Physics from the time of expensive mainframes to grids and clouds systems using thousands of multi-core processors. It focuses on the key parameters or events that have shaped the current software infrastructure.

[Flexor tendon repair: a short story].

Science.gov (United States)

Moutet, F; Corcella, D; Forli, A; Mesquida, V

2014-12-01

This short story of flexor tendon repair aims to illustrate hesitations and wanderings of this surgery. Obviously tendon repair was very early considered, but it developed and diffused rather lately. It became a routine practice only in 20th century. This was due on the one hand, in Occident, to the Galen's dogmatic interdiction, on the other hand, to the repair difficulties of this paradoxical structure. Actually tendon is made of fibroblasts and collagen (sticky substances), and then its only goal is to move. According to this necessity, whatever the used techniques are, gliding is the final purpose. Technical evolutions are illustrated by historical contributions to flexor tendon surgery of several "giants" of hand surgery. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Short range order in liquid pnictides

International Nuclear Information System (INIS)

Mayo, M; Makov, G; Yahel, E; Greenberg, Y

2013-01-01

Liquid pnictides have anomalous physical properties and complex radial distribution functions. The quasi-crystalline model of liquid structure is applied to interpret the three-dimensional structure of liquid pnictides. It is shown that all the column V elements can be characterized by a short range order lattice symmetry similar to that of the underlying solid, the A7 structure, which originates from a Peierls distorted simple cubic lattice. The evolution of the liquid structure down the column as well as its temperature and pressure dependence is interpreted by means of the effect of thermodynamic parameters on the Peierls distortion. Surprisingly, it is found that the Peierls effect increases with temperature and the nearest neighbour distances exhibit negative thermal expansion. (paper)

Geomorphological evolution of badlands based on the dynamics of ...

Indian Academy of Sciences (India)

In the light of the evidences, a modified schematic geomorphic evolution of badlands ... Chambal River follows an anti-formal up-warp. Agarwal et al. (2002) ..... Aging of sediments from .... Makaske B 2001 Anastomosing rivers: A review of their.

Role of Probiotics in Short Bowel Syndrome in Infants and Children—A Systematic Review

Directory of Open Access Journals (Sweden)

Shripada Rao

2013-03-01

Full Text Available Short bowel syndrome (SBS is a cause of significant morbidity and mortality in children. Probiotics, due to their beneficial effects on the gastrointestinal tract (e.g., improving gut barrier function, motility, facilitation of intestinal adaptation and decreasing pathogen load and inflammation may have a therapeutic role in the management of SBS. To conduct a systematic review of the current evidence for the effects of probiotic supplementation in children with SBS, the standard Cochrane methodology for systematic reviews was used. The databases, Pubmed, Embase, ACTR, CENTRAL, and the international trial registry, and reference lists of articles were searched for randomised (RCT or quasi-randomised controlled trials reporting on the use of probiotics in SBS. Our search revealed no RCTs on the use of probiotics in children with SBS. We found one small cross-over RCT (placebo controlled crossover clinical trial, one case control study and nine case reports on the use of probiotics in children with SBS. In the crossover RCT, there was no consistent effect on intestinal permeability (primary outcome after supplementation with Lactobacillus rhamnosus (LGG in nine children with SBS. The case control study (four cases: four controls reported a trend for increase in height and weight velocity and improvement in non-clinical outcomes, such as gut flora, lymphocyte count and serum prealbumin. Five of the nine case reports showed that children (n = 12 with SBS were benefited (e.g., cessation of diarrhoea, improved faecal flora, weight gain and weaning from parenteral nutrition by probiotic supplementation. The remaining four reported on the adverse effects, such as Lactobacillus sepsis (n = 3 and d-lactic acidosis (n = 2. There is insufficient evidence on the effects of probiotics in children with SBS. The safety and efficacy of probiotic supplementation in this high-risk cohort needs to be evaluated in large definitive trials.

Adaptive evolution of conserved noncoding elements in mammals.

Directory of Open Access Journals (Sweden)

Su Yeon Kim

2007-09-01

Full Text Available Conserved noncoding elements (CNCs are an abundant feature of vertebrate genomes. Some CNCs have been shown to act as cis-regulatory modules, but the function of most CNCs remains unclear. To study the evolution of CNCs, we have developed a statistical method called the "shared rates test" to identify CNCs that show significant variation in substitution rates across branches of a phylogenetic tree. We report an application of this method to alignments of 98,910 CNCs from the human, chimpanzee, dog, mouse, and rat genomes. We find that approximately 68% of CNCs evolve according to a null model where, for each CNC, a single parameter models the level of constraint acting throughout the phylogeny linking these five species. The remaining approximately 32% of CNCs show departures from the basic model including speed-ups and slow-downs on particular branches and occasionally multiple rate changes on different branches. We find that a subset of the significant CNCs have evolved significantly faster than the local neutral rate on a particular branch, providing strong evidence for adaptive evolution in these CNCs. The distribution of these signals on the phylogeny suggests that adaptive evolution of CNCs occurs in occasional short bursts of evolution. Our analyses suggest a large set of promising targets for future functional studies of adaptation.

Y-Chromosome short tandem repeat, typing technology, locus ...

African Journals Online (AJOL)

Aghomotsegin

2015-07-08

Jul 8, 2015 ... Y-Chromosome short tandem repeat, typing technology, locus information and allele frequency in different population: A review. Muhanned Abdulhasan Kareem1, Ameera Omran Hussein2 and Imad Hadi Hameed2*. 1Babylon University, Centre of Environmental Research, Hilla City, Iraq. 2Department of ...

X-Chromosome short tandem repeat, advantages and typing ...

African Journals Online (AJOL)

Microsatellites of the X-chromosome have been increasingly studied in recent years as a useful tool in forensic analysis. This review describes some details of X-chromosomal short tandem repeat (STR) analysis. Among them are: microsatellites, amplification using polymerase chain reaction (PCR) of STRs, PCR product ...

The early evolution of the atmospheres of terrestrial planets

CERN Document Server

Raulin, François; Muller, Christian; Nixon, Conor; Astrophysics and Space Science Proceedings : Volume 35

2013-01-01

“The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are ...

Short-Term Wind Speed Forecasting for Power System Operations

KAUST Repository

Zhu, Xinxin

2012-04-01

The emphasis on renewable energy and concerns about the environment have led to large-scale wind energy penetration worldwide. However, there are also significant challenges associated with the use of wind energy due to the intermittent and unstable nature of wind. High-quality short-term wind speed forecasting is critical to reliable and secure power system operations. This article begins with an overview of the current status of worldwide wind power developments and future trends. It then reviews some statistical short-term wind speed forecasting models, including traditional time series approaches and more advanced space-time statistical models. It also discusses the evaluation of forecast accuracy, in particular, the need for realistic loss functions. New challenges in wind speed forecasting regarding ramp events and offshore wind farms are also presented. © 2012 The Authors. International Statistical Review © 2012 International Statistical Institute.

Genome increase as a clock for the origin and evolution of life

Directory of Open Access Journals (Sweden)

Sharov Alexei A

2006-06-01

Full Text Available Abstract Background The size of non-redundant functional genome can be an indicator of biological complexity of living organisms. Several positive feedback mechanisms including gene cooperation and duplication with subsequent specialization may result in the exponential growth of biological complexity in macro-evolution. Results I propose a hypothesis that biological complexity increased exponentially during evolution. Regression of the logarithm of functional non-redundant genome size versus time of origin in major groups of organisms showed a 7.8-fold increase per 1 billion years, and hence the increase of complexity can be viewed as a clock of macro-evolution. A strong version of the exponential hypothesis is that the rate of complexity increase in early (pre-prokaryotic evolution of life was at most the same (or even slower than observed in the evolution of prokaryotes and eukaryotes. Conclusion The increase of functional non-redundant genome size in macro-evolution was consistent with the exponential hypothesis. If the strong exponential hypothesis is true, then the origin of life should be dated 10 billion years ago. Thus, the possibility of panspermia as a source of life on earth should be discussed on equal basis with alternative hypotheses of de-novo life origin. Panspermia may be proven if bacteria similar to terrestrial ones are found on other planets or satellites in the solar system. Reviewers This article was reviewed by Eugene V. Koonin, Chris Adami and Arcady Mushegian.

The Co-evolution of Language and the Brain: A Review of Two Contrastive Views (Pinker & Deacon)

DEFF Research Database (Denmark)

Christensen, Ken Ramshøj

2001-01-01

in a larger symbolic computational chain controlled by regions in the frontal parts of the brain. To Deacon, a symbolic learning algorithm drives language acquisition. The increase in size of the human brain in relation to the body may be due to a “cognitive arms race”. Both Pinker and Deacon agree......This article is a review of two contrastive views on the co-evolution of language and the brain – The Language Instinct by Steven Pinker (1994) and The Symbolic Species by Terrence Deacon (1997). As language is a trait unique to mankind it can not be equated with nonlinguistic communication – human...... or nonhuman. This points to a special human brain architecture. Pinker’s claim is that certain areas on the left side of the brain constitute a language organ and that language acquisition is instinctual. To Deacon, however, those areas are non-language-specific computational centers. Moreover, they are parts...

5S rRNA gene arrangements in protists: a case of nonadaptive evolution.

Science.gov (United States)

Drouin, Guy; Tsang, Corey

2012-06-01

Given their high copy number and high level of expression, one might expect that both the sequence and organization of eukaryotic ribosomal RNA genes would be conserved during evolution. Although the organization of 18S, 5.8S and 28S ribosomal RNA genes is indeed relatively well conserved, that of 5S rRNA genes is much more variable. Here, we review the different types of 5S rRNA gene arrangements which have been observed in protists. This includes linkages to the other ribosomal RNA genes as well as linkages to ubiquitin, splice-leader, snRNA and tRNA genes. Mapping these linkages to independently derived phylogenies shows that these diverse linkages have repeatedly been gained and lost during evolution. This argues against such linkages being the primitive condition not only in protists but also in other eukaryote species. Because the only characteristic the diverse genes with which 5S rRNA genes are found linked with is that they are tandemly repeated, these arrangements are unlikely to provide any selective advantage. Rather, the observed high variability in 5S rRNA genes arrangements is likely the result of the fact that 5S rRNA genes contain internal promoters, that these genes are often transposed by diverse recombination mechanisms and that these new gene arrangements are rapidly homogenized by unequal crossingovers and/or by gene conversions events in species with short generation times and frequent founder events.

Short-term Effect of Fine Particulate Matter on Children?s Hospital Admissions and Emergency Department Visits for Asthma: A Systematic Review and Meta-analysis

OpenAIRE

Lim, Hyungryul; Kwon, Ho-Jang; Lim, Ji-Ae; Choi, Jong Hyuk; Ha, Mina; Hwang, Seung-Sik; Choi, Won-Jun

2016-01-01

Objectives: No children-specified review and meta-analysis paper about the short-term effect of fine particulate matter (PM2.5) on hospital admissions and emergency department visits for asthma has been published. We calculated more precise pooled effect estimates on this topic and evaluated the variation in effect size according to the differences in study characteristics not considered in previous studies. Methods: Two authors each independently searched PubMed and EMBASE for relevant studi...

Short-term Forecasting Tools for Agricultural Nutrient Management.

Science.gov (United States)

Easton, Zachary M; Kleinman, Peter J A; Buda, Anthony R; Goering, Dustin; Emberston, Nichole; Reed, Seann; Drohan, Patrick J; Walter, M Todd; Guinan, Pat; Lory, John A; Sommerlot, Andrew R; Sharpley, Andrew

2017-11-01

The advent of real-time, short-term farm management tools is motivated by the need to protect water quality above and beyond the general guidance offered by existing nutrient management plans. Advances in high-performance computing and hydrologic or climate modeling have enabled rapid dissemination of real-time information that can assist landowners and conservation personnel with short-term management planning. This paper reviews short-term decision support tools for agriculture that are under various stages of development and implementation in the United States: (i) Wisconsin's Runoff Risk Advisory Forecast (RRAF) System, (ii) New York's Hydrologically Sensitive Area Prediction Tool, (iii) Virginia's Saturated Area Forecast Model, (iv) Pennsylvania's Fertilizer Forecaster, (v) Washington's Application Risk Management (ARM) System, and (vi) Missouri's Design Storm Notification System. Although these decision support tools differ in their underlying model structure, the resolution at which they are applied, and the hydroclimates to which they are relevant, all provide forecasts (range 24-120 h) of runoff risk or soil moisture saturation derived from National Weather Service Forecast models. Although this review highlights the need for further development of robust and well-supported short-term nutrient management tools, their potential for adoption and ultimate utility requires an understanding of the appropriate context of application, the strategic and operational needs of managers, access to weather forecasts, scales of application (e.g., regional vs. field level), data requirements, and outreach communication structure. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Respiratory mechanics in brain injury: A review.

Science.gov (United States)

Koutsoukou, Antonia; Katsiari, Maria; Orfanos, Stylianos E; Kotanidou, Anastasia; Daganou, Maria; Kyriakopoulou, Magdalini; Koulouris, Nikolaos G; Rovina, Nikoletta

2016-02-04

Several clinical and experimental studies have shown that lung injury occurs shortly after brain damage. The responsible mechanisms involve neurogenic pulmonary edema, inflammation, the harmful action of neurotransmitters, or autonomic system dysfunction. Mechanical ventilation, an essential component of life support in brain-damaged patients (BD), may be an additional traumatic factor to the already injured or susceptible to injury lungs of these patients thus worsening lung injury, in case that non lung protective ventilator settings are applied. Measurement of respiratory mechanics in BD patients, as well as assessment of their evolution during mechanical ventilation, may lead to preclinical lung injury detection early enough, allowing thus the selection of the appropriate ventilator settings to avoid ventilator-induced lung injury. The aim of this review is to explore the mechanical properties of the respiratory system in BD patients along with the underlying mechanisms, and to translate the evidence of animal and clinical studies into therapeutic implications regarding the mechanical ventilation of these critically ill patients.

Changing-Look AGNs or Short-Lived Radio Sources?

Energy Technology Data Exchange (ETDEWEB)

Wołowska, Aleksandra [Toruń Centre for Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Toruń (Poland); Kunert-Bajraszewska, Magdalena; Mooley, Kunal [Centre for Astrophysical Surveys, University of Oxford, Oxford (United Kingdom); Hallinan, Gregg, E-mail: ola@astro.umk.pl [Cahill Center for Astronomy, California Institute of Technology, Pasadena, CA (United States)

2017-11-17

The evolution of extragalactic radio sources has been a fundamental problem in the study of active galactic nuclei for many years. A standard evolutionary model has been created based on observations of a wide range of radio sources. In the general scenario of the evolution, the younger and smaller Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources become large-scale FRI and FRII objects. However, a growing number of observations of low power radio sources suggests that the model cannot explain all their properties and there are still some aspects of the evolutionary path that remain unclear. There are indications, that some sources may be short-lived objects on timescales of 10{sup 4}–10{sup 5} years. Those objects represent a new population of active galaxies. Here, we present the discovery of several radio transient sources on timescales of 5–20 yrs, largely associated with renewed AGN (Active Galactic Nucleus) activity. These changing-look AGNs possibly represent behavior typical for many active galaxies.

Plant retroviruses: structure, evolution and future applications | Zaki ...

African Journals Online (AJOL)

Until recently, retroviruses were thought to be restricted to vertebrates. Plant sequencing projects revealed that plant genomes contain retroviral-like sequences. This review aims to address the structure and evolution of plant retroviruses. In addition, it proposes future applications for these important key components of plant ...

Evolution of Positioning Techniques in Cellular Networks, from 2G to 4G

Directory of Open Access Journals (Sweden)

Rafael Saraiva Campos

2017-01-01

Full Text Available This review paper presents within a common framework the mobile station positioning methods applied in 2G, 3G, and 4G cellular networks, as well as the structure of the related 3GPP technical specifications. The evolution path through the generations is explored in three steps at each level: first, the new network elements supporting localization features are introduced; then, the standard localization methods are described; finally, the protocols providing specific support to mobile station positioning are studied. To allow a better understanding, this paper also brings a brief review of the cellular networks evolution paths.

EXAFS study of short range order in Fe-Zr amorphous alloys

International Nuclear Information System (INIS)

Fernandez-Gubieda, M.L.; Gorria, P.; Barandiaran, J.M.; Barquin, L.F.

1995-01-01

Room temperature X-ray absorption spectra on Fe K-edge have been performed in Fe 100-x-y Zr x B y and Fe 86 Zr 7 Cu 1 B 6 alloys (x=7, 7.7, 9; y=0, 2, 4, 6). Fe-Fe coordination number and interatomic distances do not change in any sample. However, small changes in the Fe-Zr short range order, which could explain the evolution of the magnetic properties, have been observed. (orig.)

Orbital atherectomy: device evolution and clinical data.

Science.gov (United States)

Staniloae, Cezar S; Korabathina, Ravikiran

2014-05-01

A number of atherectomy devices were developed in the last few years. Among them, the DiamondBack 360° Peripheral Orbital Atherectomy System (Cardiovascular Systems, Inc) was specifically designed to work in severely calcified plaque. This article reviews the history, mechanism of action, evolution, clinical data, and future applications of this particular atherectomy device.

Neogene climate evolution in Amazonia and the Brazilian Northeast

NARCIS (Netherlands)

Hoorn, C.; Bernardes-de-Oliveira, M.E.C.; Dino, R.; Garcia, M.J.; Antonioli, L.; da Costa Casado, F.; Hooghiemstra, H.; de Souza Carvalho, I.; Garcia, M.J.; Strohschoen, O.; Cunha Lana, C.

2014-01-01

Climate change follows from the interaction between global atmospheric and oceanic processes with regional processes. In this chapter we review which factors determined climate evolution in Amazonia and the Brazilian Northeast and present a recompilation of Neogene palynological and paleobotanical

Microstructure and elemental distribution of americium containing MOX fuel under the short term irradiation tests

International Nuclear Information System (INIS)

Tanaka, Kosuke; Hirosawa, Takashi; Obayashi, Hiroshi; Koyama, Shin Ichi; Yoshimochi, Hiroshi; Tanaka, Kenya

2008-01-01

In order to investigate the effect of americium addition to MOX fuels on the irradiation behavior, the 'Am-1' program is being conducted in JAEA. The Am-1 program consists of two short term irradiation tests of 10-minute and 24 hour irradiations and a steady-state irradiation test. The short-term irradiation tests were successfully completed and the post irradiation examinations (PIEs) are in progress. The PIEs for Am-containing MOX fuels focused on the microstructural evolution and redistribution behavior of Am at the initial stage of irradiation and the results to date are reported

Whole Genome Sequencing Identifies a Missense Mutation in HES7 Associated with Short Tails in Asian Domestic Cats.

Science.gov (United States)

Xu, Xiao; Sun, Xin; Hu, Xue-Song; Zhuang, Yan; Liu, Yue-Chen; Meng, Hao; Miao, Lin; Yu, He; Luo, Shu-Jin

2016-08-25

Domestic cats exhibit abundant variations in tail morphology and serve as an excellent model to study the development and evolution of vertebrate tails. Cats with shortened and kinked tails were first recorded in the Malayan archipelago by Charles Darwin in 1868 and remain quite common today in Southeast and East Asia. To elucidate the genetic basis of short tails in Asian cats, we built a pedigree of 13 cats segregating at the trait with a founder from southern China and performed linkage mapping based on whole genome sequencing data from the pedigree. The short-tailed trait was mapped to a 5.6 Mb region of Chr E1, within which the substitution c. 5T > C in the somite segmentation-related gene HES7 was identified as the causal mutation resulting in a missense change (p.V2A). Validation in 245 unrelated cats confirmed the correlation between HES7-c. 5T > C and Chinese short-tailed feral cats as well as the Japanese Bobtail breed, indicating a common genetic basis of the two. In addition, some of our sampled kinked-tailed cats could not be explained by either HES7 or the Manx-related T-box, suggesting at least three independent events in the evolution of domestic cats giving rise to short-tailed traits.

Short-term intensive insulin therapy in type 2 diabetes mellitus: a systematic review and meta-analysis.

Science.gov (United States)

Kramer, Caroline Kaercher; Zinman, Bernard; Retnakaran, Ravi

2013-09-01

Studies have shown that, when implemented early in the course of type 2 diabetes mellitus, treatment with intensive insulin therapy for 2-3 weeks can induce a glycaemic remission, wherein patients are able to maintain normoglycaemia without any anti-diabetic medication. We thus did a systematic review and meta-analysis of interventional studies to assess the effect of short-term intensive insulin therapy on the pathophysiological defects underlying type 2 diabetes mellitus (pancreatic β-cell dysfunction and insulin resistance) and identify clinical predictors of remission. We identified studies published between 1950 and Nov 19, 2012, which assessed the effect of intensive insulin therapy on β-cell function or insulin resistance, or both, or assessed long-term drug-free glycaemic remission in adults aged 18 years or older with newly diagnosed type 2 diabetes mellitus. We calculated pooled estimates by random-effects model. This study is registered with International Prospective Register of Systematic Reviews, number CRD42012002829. We identified 1645 studies of which seven fulfilled inclusion criteria (n=839 participants). Five studies were non-randomised. A pooled analysis of the seven studies showed a post-intensive insulin therapy increase in Homeostasis Model Assessment of β-cell function as compared with baseline (1·13, 95% CI 1·02 to 1·25) and a decrease in Homeostasis Model Assessment of Insulin Resistance (-0·57, -0·84 to -0·29). In the four studies that assessed glycaemic remission (n=559 participants), the proportion of participants in drug-free remission was about 66·2% (292 of 441 patients) after 3 months of follow-up, about 58·9% (222 of 377 patients) after 6 months, about 46·3% (229 of 495 patients) after 12 months, and about 42·1% (53 of 126 patients) after 24 months. Patients who achieved remission had higher body-mass index than those who did not achieve remission (1·06 kg/m(2), 95% CI 0·55 to 1·58) and lower fasting plasma glucose

Anti-tumor promoting potential of selected spice ingredients with antioxidative and anti-inflammatory activities: a short review.

Science.gov (United States)

Surh, Young-Joon

2002-08-01

A wide variety of phenolic substances derived from spice possess potent antimutagenic and anticarcinogenic activities. Examples are curcumin, a yellow colouring agent, contained in turmeric (Curcuma longa L., Zingiberaceae), [6]-gingerol, a pungent ingredient present in ginger (Zingiber officinale Roscoe, Zingiberaceae) and capsaicin, a principal pungent principle of hot chili pepper (Capsicum annuum L, Solanaceae). The chemopreventive effects exerted by these phytochemicals are often associated with their antioxidative and anti-inflammatory activities. Cyclo-oxygenase-2 (COX-2) has been recognized as a molecular target of many chemopreventive as well as anti-inflammatory agents. Recent studies have shown that COX-2 is regulated by the eukaryotic transcription factor NF-kappaB. This short review summarizes the molecular mechanisms underlying chemopreventive effects of the aforementioned spice ingredients in terms of their effects on intracellular signaling cascades, particularly those involving NF-kappaB and mitogen-activated protein kinases.

Mechanised harvesting of short-rotation coppices

OpenAIRE

Vanbeveren, Stefan P.P.; Spinelli, Raffaele; Eisenbies, Mark; Schweier, Janine; Mola-Yudego, Blas; Magagnotti, Natascia; Acuna, Mauricio; Dimitriou, Ioannis; Ceulemans, Reinhart

2017-01-01

Abstract: Short-rotation coppice (SRC) is an important source of woody biomass for bioenergy. Despite the research carried out on several aspects of SRC production, many uncertainties create barriers to farmers establishing SRC plantations. One of the key economic sources of uncertainty is harvesting methods and costs; more specifically, the performance of contemporary machine methods is reviewed. We collected data from 25 literature references, describing 166 field trials. Three harvesting s...

Evolution and genome architecture in fungal plant pathogens.

Science.gov (United States)

Möller, Mareike; Stukenbrock, Eva H

2017-12-01

The fungal kingdom comprises some of the most devastating plant pathogens. Sequencing the genomes of fungal pathogens has shown a remarkable variability in genome size and architecture. Population genomic data enable us to understand the mechanisms and the history of changes in genome size and adaptive evolution in plant pathogens. Although transposable elements predominantly have negative effects on their host, fungal pathogens provide prominent examples of advantageous associations between rapidly evolving transposable elements and virulence genes that cause variation in virulence phenotypes. By providing homogeneous environments at large regional scales, managed ecosystems, such as modern agriculture, can be conducive for the rapid evolution and dispersal of pathogens. In this Review, we summarize key examples from fungal plant pathogen genomics and discuss evolutionary processes in pathogenic fungi in the context of molecular evolution, population genomics and agriculture.

Periprosthetic bone remodelling of short-stem total hip arthroplasty: a systematic review.

Science.gov (United States)

Yan, Shuang G; Weber, Patrick; Steinbrück, Arnd; Hua, Xingyi; Jansson, Volkmar; Schmidutz, Florian

2017-11-27

Short-stem hip arthroplasty (SHA) was designed to preserve bone stock and provide an improved load transfer. To gain more evidence regarding the load transfer, this review analysed the periprosthetic bone remodelling of SHA in comparison to standard hip arthroplasty (THA). PubMed and ScienceDirect were screened to extract dual-energy X-ray absorptiometry (DXA) studies evaluating the periprosthetic bone remodelling of SHA and two proven THA designs. From the studies included, the postoperative change in periprosthetic bone mineral density (BMD) after one year and the trend over two years was determined. Fifteen studies with four SHAs (CFP, Metha, Nanos, Fitmore) and two THAs (CLS and Bicontact) designs were included. All SHA and THA stems revealed an initial decrease at the calcar and major trochanter (Gruen 1 and 7) with the Metha, Nanos and Fitmore showing a smaller and more balanced remodelling compared to THA. The pattern after one year and the trend over two years argue for a methaphyseal anchorage of the Metha and Nanos, whereas the Fitmore and CFP seem to anchor metha-diaphyseal. Clearly different pattern of bone remodelling were observed between all four SHAs. Periprosthetic bone remodelling is also present in SHA, with the main bone reduction observed proximally. However, certain SHA stems show a more balanced remodelling compared to THA, arguing for a favourable load transfer. Also, the femoral length where bone remodelling occurs is clearly shorter in SHA. As distinctively different pattern between the SHA designs were observed, they should not be judged as a single implant group.

Short dental implants: an emerging concept in implant treatment.

Science.gov (United States)

Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

2014-06-01

Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

A multi-frequency approach to free electron lasers driven by short electron bunches

International Nuclear Information System (INIS)

Piovella, Nicola

1997-01-01

A multi-frequency model for free electron lasers (FELs), based on the Fourier decomposition of the radiation field coupled with the beam electrons, is discussed. We show that the multi-frequency approach allows for an accurate description of the evolution of the radiation spectrum, also when the FEL is driven by short electron bunches, of arbitrary longitudinal profile. We derive from the multi-frequency model, by averaging over one radiation period, the usual FEL equations modelling the slippage between radiation and particles and describing the super-radiant regime in high-gain FELs. As an example of application of the multi-frequency model, we discuss the coherent spontaneous emission (CSE) from short electron bunches

Benchmarking the Stability of Oxygen Evolution Reaction Catalysts

DEFF Research Database (Denmark)

Frydendal, Rasmus; Paoli, Elisa Antares; Knudsen, Brian Peter

2014-01-01

Because of the rising need for energy storage, potentially facilitated by electrolyzers, improvements to the catalysis of the oxygen evolution reaction (OER) become increasingly relevant. Standardized protocols have been developed for determining critical figures of merit, such as the electrochem......Because of the rising need for energy storage, potentially facilitated by electrolyzers, improvements to the catalysis of the oxygen evolution reaction (OER) become increasingly relevant. Standardized protocols have been developed for determining critical figures of merit...... coupled plasma mass spectrometry (ICP–MS). We show that a meaningful estimation of the stability cannot be achieved based on purely electrochemical tests. On the catalysts tested, the anodic dissolution current was four orders of magnitude lower than the total current. We propose that even if long......-term testing cannot be replaced, a useful evaluation of the stability can be achieved with short-term tests by using EQCM or ICP–MS....

Distribution, Diversity, and Long-Term Retention of Grass Short Interspersed Nuclear Elements (SINEs).

Science.gov (United States)

Mao, Hongliang; Wang, Hao

2017-08-01

Instances of highly conserved plant short interspersed nuclear element (SINE) families and their enrichment near genes have been well documented, but little is known about the general patterns of such conservation and enrichment and underlying mechanisms. Here, we perform a comprehensive investigation of the structure, distribution, and evolution of SINEs in the grass family by analyzing 14 grass and 5 other flowering plant genomes using comparative genomics methods. We identify 61 SINE families composed of 29,572 copies, in which 46 families are first described. We find that comparing with other grass TEs, grass SINEs show much higher level of conservation in terms of genomic retention: The origin of at least 26% families can be traced to early grass diversification and these families are among most abundant SINE families in 86% species. We find that these families show much higher level of enrichment near protein coding genes than families of relatively recent origin (51%:28%), and that 40% of all grass SINEs are near gene and the percentage is higher than other types of grass TEs. The pattern of enrichment suggests that differential removal of SINE copies in gene-poor regions plays an important role in shaping the genomic distribution of these elements. We also identify a sequence motif located at 3' SINE end which is shared in 17 families. In short, this study provides insights into structure and evolution of SINEs in the grass family. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Natural genetic engineering: intelligence & design in evolution?

DEFF Research Database (Denmark)

Ussery, David

2011-01-01

There are many things that I like about James Shapiro's new book "Evolution: A View from the 21st Century" (FT Press Science, 2011). He begins the book by saying that it is the creation of novelty, and not selection, that is important in the history of life. In the presence of heritable traits...... function. Shapiro argues that what we see in genomes is 'Natural Genetic Engineering', or designed evolution: "Thinking about genomes from an informatics perspective, it is apparent that systems engineering is a better metaphor for the evolutionary process than the conventional view of evolution...... as a select-biased random walk through limitless space of possible DNA configurations" (page 6). In this review, I will have a look at four topics: 1.) why I think genomics is not the whole story; 2.) my own perspective of E. coli genomics, and how I think it relates to this book; 3.) a brief discussion...

Faster-X evolution: Theory and evidence from Drosophila.

Science.gov (United States)

Charlesworth, Brian; Campos, José L; Jackson, Benjamin C

2018-02-12

A faster rate of adaptive evolution of X-linked genes compared with autosomal genes can be caused by the fixation of recessive or partially recessive advantageous mutations, due to the full expression of X-linked mutations in hemizygous males. Other processes, including recombination rate and mutation rate differences between X chromosomes and autosomes, may also cause faster evolution of X-linked genes. We review population genetics theory concerning the expected relative values of variability and rates of evolution of X-linked and autosomal DNA sequences. The theoretical predictions are compared with data from population genomic studies of several species of Drosophila. We conclude that there is evidence for adaptive faster-X evolution of several classes of functionally significant nucleotides. We also find evidence for potential differences in mutation rates between X-linked and autosomal genes, due to differences in mutational bias towards GC to AT mutations. Many aspects of the data are consistent with the male hemizygosity model, although not all possible confounding factors can be excluded. © 2018 John Wiley & Sons Ltd.

Short-run and Current Analysis Model in Statistics

Directory of Open Access Journals (Sweden)

Constantin Anghelache

2006-01-01

Full Text Available Using the short-run statistic indicators is a compulsory requirement implied in the current analysis. Therefore, there is a system of EUROSTAT indicators on short run which has been set up in this respect, being recommended for utilization by the member-countries. On the basis of these indicators, there are regular, usually monthly, analysis being achieved in respect of: the production dynamic determination; the evaluation of the short-run investment volume; the development of the turnover; the wage evolution: the employment; the price indexes and the consumer price index (inflation; the volume of exports and imports and the extent to which the imports are covered by the exports and the sold of trade balance. The EUROSTAT system of indicators of conjuncture is conceived as an open system, so that it can be, at any moment extended or restricted, allowing indicators to be amended or even removed, depending on the domestic users requirements as well as on the specific requirements of the harmonization and integration. For the short-run analysis, there is also the World Bank system of indicators of conjuncture, which is utilized, relying on the data sources offered by the World Bank, The World Institute for Resources or other international organizations statistics. The system comprises indicators of the social and economic development and focuses on the indicators for the following three fields: human resources, environment and economic performances. At the end of the paper, there is a case study on the situation of Romania, for which we used all these indicators.

Short-run and Current Analysis Model in Statistics

Directory of Open Access Journals (Sweden)

Constantin Mitrut

2006-03-01

Full Text Available Using the short-run statistic indicators is a compulsory requirement implied in the current analysis. Therefore, there is a system of EUROSTAT indicators on short run which has been set up in this respect, being recommended for utilization by the member-countries. On the basis of these indicators, there are regular, usually monthly, analysis being achieved in respect of: the production dynamic determination; the evaluation of the short-run investment volume; the development of the turnover; the wage evolution: the employment; the price indexes and the consumer price index (inflation; the volume of exports and imports and the extent to which the imports are covered by the exports and the sold of trade balance. The EUROSTAT system of indicators of conjuncture is conceived as an open system, so that it can be, at any moment extended or restricted, allowing indicators to be amended or even removed, depending on the domestic users requirements as well as on the specific requirements of the harmonization and integration. For the short-run analysis, there is also the World Bank system of indicators of conjuncture, which is utilized, relying on the data sources offered by the World Bank, The World Institute for Resources or other international organizations statistics. The system comprises indicators of the social and economic development and focuses on the indicators for the following three fields: human resources, environment and economic performances. At the end of the paper, there is a case study on the situation of Romania, for which we used all these indicators.

Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

Science.gov (United States)

Gleeson, Dianne; Georges, Arthur

2018-01-01

Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata) which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways. PMID:29751579

Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

Directory of Open Access Journals (Sweden)

Shayer Mahmood Ibney Alam

2018-05-01

Full Text Available Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD and temperature-dependent sex determination (TSD within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways.

Short-term energy outlook annual supplement, 1993

International Nuclear Information System (INIS)

1993-01-01

The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the third quarter of 1993 through the fourth quarter of 1994. Values for the second quarter of 1993, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data are EIA data published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding

Personal assistance services in the workplace: A literature review.

Science.gov (United States)

Dowler, Denetta L; Solovieva, Tatiana I; Walls, Richard T

2011-10-01

Personal assistance services (PAS) can be valuable adjuncts to the complement of accommodations that support workers with disabilities. This literature review explored the professional literature on the use of PAS in the workplace. Bibliographic sources were used to locate relevant research studies on the use of PAS in the workplace. The studies in this review used both qualitative and quantitative methods to identify current definitions of work-related and personal care-related PAS, agency-directed versus consumer-directed PAS, long-term and short-term funding issues, development of PAS policy, and barriers to successful implementation of PAS. The studies uncovered issues related to (a) recruiting, training, and retaining personal assistants, (b) employer concerns, (c) costs and benefits of workplace PAS, (d) wages and incentives for personal assistants, and (e) sources for financing PAS as a workplace accommodation. The findings reveal the value and benefits of effective PAS on the job. PAS can lead to successful employment of people with disabilities when other accommodations cannot provide adequate workplace support. Additionally, the evolution of workplace PAS is dependent on development of realistic PAS policy and funding options. Published by Elsevier Inc.

A short review on photocatalytic degradation of formaldehyde

NARCIS (Netherlands)

Tasbihi, M.; Bendyna, J.K.; Notten, P.H.L.; Hintzen, H.T.J.M.

2015-01-01

Nowadays, it is a great challenge to eliminate toxic and harmful organic pollutants from air and water. This paper reviews the role of TiO2 as a photocatalyst, light source and photoreactor in the particular case of removal of formaldehyde using the photocatalytic reaction by titanium dioxide (TiO2

Glucosinolate structures in evolution.

Science.gov (United States)

Agerbirk, Niels; Olsen, Carl Erik

2012-05-01

By 2000, around 106 natural glucosinolates (GSLs) were probably documented. In the past decade, 26 additional natural GSL structures have been elucidated and documented. Hence, the total number of documented GSLs from nature by 2011 can be estimated to around 132. A considerable number of additional suggested structures are concluded not to be sufficiently documented. In many cases, NMR spectroscopy would have provided the missing structural information. Of the GSLs documented in the past decade, several are of previously unexpected structures and occur at considerable levels. Most originate from just four species: Barbarea vulgaris, Arabidopsis thaliana, Eruca sativa and Isatis tinctoria. Acyl derivatives of known GSLs comprised 15 of the 26 newly documented structures, while the remaining exhibited new substitution patterns or chain length, or contained a mercapto group or related thio-functionality. GSL identification methods are reviewed, and the importance of using authentic references and structure-sensitive detection methods such as MS and NMR is stressed, especially when species with relatively unknown chemistry are analyzed. An example of qualitative GSL analysis is presented with experimental details (group separation and HPLC of both intact and desulfated GSLs, detection and structure determination by UV, MS, NMR and susceptibility to myrosinase) with emphasis on the use of NMR for structure elucidation of even minor GSLs and GSL hydrolysis products. The example includes identification of a novel GSL, (R)-2-hydroxy-2-(3-hydroxyphenyl)ethylglucosinolate. Recent investigations of GSL evolution, based on investigations of species with well established phylogeny, are reviewed. From the relatively few such investigations, it is already clear that GSL profiles are regularly subject to evolution. This result is compatible with natural selection for specific GSL side chains. The probable existence of structure-specific GSL catabolism in intact plants suggests

SHORT REVIEW ON EUROPEAN TURISM IN 2010 THROUGH THE INFLUENCE OF THE FINANCIAL CRISIS

Directory of Open Access Journals (Sweden)

MARINOIU ANA - MARIA

2011-12-01

Full Text Available The aim of the present research paper is to present a short review on the European turism in 2010 through the influence of the financial crisis. The importance of the paper resides in the presentation of the impact that the economic downturn had on the European tourism, taking a closer look also in the investment in hotel industry in 2010. The paper’s objectives took into consideration the current situation and by proposing the rural tourism as an alternative we offer a solution in order to minimise its effects on this specific activity sector. The subject has not been extensively debated in the specialized literature even though it represents a current issue both regarding the private business environment as well as the main national and international bodies that regulate the tourism industry. The research metodology consists in a SWOT analysis through which we prove the rural and ecotourism to be a viable solution in order to minimise the downturn of the industry for countries in CEE. The added value of the paper consists in the analysis of o subject that is too little taken into consideration and of big importance for the companies acting in this specific domain.

Short Bowel Syndrome, a Case of Intestinal Rehabilitation

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Dianna Ramírez Prada

2015-05-01

Full Text Available Case: The objective is to present the successful experience of multidisciplinary management of a patient with short bowel syndrome and intestinal failure with progression to intestinal adaptation. This is a newly born premature with intestinal atresia type IV with multiple intestinal atresia who evolved to intestinal failure and required managed with prolonged parenteral nutritional support, multiple antibiotic schemes, prebiotics, multivitamins, enteral nutrition with elemental formula to achieve their adaptation intestinal until lead to a normal diet. The evolution of these patients intestinal failure is a challenge for the health team, as it not only involves the surgical management of your condition if not basic nutritional support, fluid and electrolyte balance, hepatic dysfunction cholestasis associated infections etc. Discussion: Short bowel syndrome with progression to intestinal failure in children is a condition whose prevalence is increasing worldwide, thanks to advances in neonatal intensive care, neonatal surgery, and nutritional support of patients with conditions such as gastroschisis, omphalocele and necrotizing enterocolitis. Despite the limitations of our health system, it is possible to offer a multidisciplinary and integrated to lead to intestinal adaptation treatment.

Short-Term Effect of Ambient Temperature and the Risk of Stroke: A Systematic Review and Meta-Analysis

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Hui Lian

2015-07-01

Full Text Available Background and Purpose: The relationship between stroke and short-term temperature changes remains controversial. Therefore, we conducted a systematic review and meta-analysis to investigate the association between stroke and both high and low temperatures, and health assessment. Methods: We searched PubMed, Embase, Cochrane, China National Knowledge Infrastructure (CNKI and Wanfang Data up to 14 September 2014. Study selection, quality assessment, and author-contractions were steps before data extraction. We converted all estimates effects into relative risk (RR per 1 °C increase/decrease in temperature from 75th to 99th or 25th to 1st percentiles, then conducted meta-analyses to combine the ultimate RRs, and assessed health impact among the population. Results: 20 articles were included in the final analysis. The overall analysis showed a positive relationship between 1 °C change and the occurrence of major adverse cerebrovascular events (MACBE, 1.1% (95% confidence intervals (CI, 0.6 to 1.7 and 1.2% (95% CI, 0.8 to 1.6 increase for hot and cold effects separately. The same trends can be found in both effects of mortality and the cold effect for morbidity. Hot temperature acted as a protective factor of hemorrhage stroke (HS, −1.9% (95% CI, −2.8 to −0.9, however, it acted as a risk factor for ischemic stroke (IS, 1.2% (95% CI, 0.7 to 1.8. Conclusion: Short-term changes of both low and high temperature had statistically significant impacts on MACBE.

Audiovisual Review

Science.gov (United States)

Physiology Teacher, 1976

1976-01-01

Lists and reviews recent audiovisual materials in areas of medical, dental, nursing and allied health, and veterinary medicine; undergraduate, and high school studies. Each is classified as to level, type of instruction, usefulness, and source of availability. Topics include respiration, renal physiology, muscle mechanics, anatomy, evolution,…

Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

Science.gov (United States)

Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H. Y.; Fu, B. Q.; Li, M.; Liu, W.

2013-02-01

Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/Tmax) was found and accordingly the activation energy for grain growth in temperature evolution up to Tmax in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads.

Air quality: evolution of monitoring methods at its height

International Nuclear Information System (INIS)

Legros, E.J.

1996-01-01

In the context of the forthcoming enforcement of the new air law in France, the INERIS (the French National Institute for Industrial Environment and Risks) made a statement at the end of June 1996 about the problems of air quality monitoring and the evolution of measurement tools. This short paper recalls first the historical evolution of the French urban air quality monitoring and its legal aspects, and the recent studies about the cost of air pollution and the impact of diesel particulates, benzene and aromatic hydrocarbons on human health. Then it describes the INERIS works concerning the identification and characterization of pollutants (NOx, CO, CO 2 , SO 2 , lead, ozone, particulates, organic volatile compounds) and the modeling of their dispersion. The monitoring of air quality in France is performed by 31 associations, from which Airparif is devoted to Paris city. (J.S.)

Can Evolution Supply What Ecology Demands?

Science.gov (United States)

Kokko, Hanna; Chaturvedi, Anurag; Croll, Daniel; Fischer, Martin C; Guillaume, Frédéric; Karrenberg, Sophie; Kerr, Ben; Rolshausen, Gregor; Stapley, Jessica

2017-03-01

A simplistic view of the adaptive process pictures a hillside along which a population can climb: when ecological 'demands' change, evolution 'supplies' the variation needed for the population to climb to a new peak. Evolutionary ecologists point out that this simplistic view can be incomplete because the fitness landscape changes dynamically as the population evolves. Geneticists meanwhile have identified complexities relating to the nature of genetic variation and its architecture, and the importance of epigenetic variation is under debate. In this review, we highlight how complexity in both ecological 'demands' and the evolutionary 'supply' influences organisms' ability to climb fitness landscapes that themselves change dynamically as evolution proceeds, and encourage new synthetic effort across research disciplines towards ecologically realistic studies of adaptation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Robotic instrumentation: Evolution and microsurgical applications

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Sijo J Parekattil

2010-01-01

Full Text Available This article presents a review of the history and evolution of robotic instrumentation and its applications in urology. A timeline for the evolution of robotic instrumentation is presented to better facilitate an understanding of our current-day applications. Some new directions including robotic microsurgical applications (robotic assisted denervation of the spermatic cord for chronic orchialgia and robotic assisted vasectomy reversal are presented. There is a paucity of prospective comparative effectiveness studies for a number of robotic applications. However, right or wrong, human nature has always led to our infatuation with the concept of using tools to meet our needs. This chapter is a brief tribute to where we have come from and where we may be potentially heading in the field of robotic assisted urologic surgery.

Comparative genomics of 28 Salmonella enterica isolates: evidence for CRISPR-mediated adaptive sublineage evolution.

Science.gov (United States)

Fricke, W Florian; Mammel, Mark K; McDermott, Patrick F; Tartera, Carmen; White, David G; Leclerc, J Eugene; Ravel, Jacques; Cebula, Thomas A

2011-07-01

Despite extensive surveillance, food-borne Salmonella enterica infections continue to be a significant burden on public health systems worldwide. As the S. enterica species comprises sublineages that differ greatly in antigenic representation, virulence, and antimicrobial resistance phenotypes, a better understanding of the species' evolution is critical for the prediction and prevention of future outbreaks. The roles that virulence and resistance phenotype acquisition, exchange, and loss play in the evolution of S. enterica sublineages, which to a certain extent are represented by serotypes, remains mostly uncharacterized. Here, we compare 17 newly sequenced and phenotypically characterized nontyphoidal S. enterica strains to 11 previously sequenced S. enterica genomes to carry out the most comprehensive comparative analysis of this species so far. These phenotypic and genotypic data comparisons in the phylogenetic species context suggest that the evolution of known S. enterica sublineages is mediated mostly by two mechanisms, (i) the loss of coding sequences with known metabolic functions, which leads to functional reduction, and (ii) the acquisition of horizontally transferred phage and plasmid DNA, which provides virulence and resistance functions and leads to increasing specialization. Matches between S. enterica clustered regularly interspaced short palindromic repeats (CRISPR), part of a defense mechanism against invading plasmid and phage DNA, and plasmid and prophage regions suggest that CRISPR-mediated immunity could control short-term phenotype changes and mediate long-term sublineage evolution. CRISPR analysis could therefore be critical in assessing the evolutionary potential of S. enterica sublineages and aid in the prediction and prevention of future S. enterica outbreaks.

Symmetry of anomalous dimension matrices for colour evolution of hard scattering processes

International Nuclear Information System (INIS)

Seymour, Michael H.

2005-01-01

In a recent paper, Dokshitzer and Marchesini rederived the anomalous dimension matrix for colour evolution of gg→gg scattering, first derived by Kidonakis, Oderda and Sterman. They noted a weird symmetry that it possesses under interchange of internal (colour group) and external (scattering angle) degrees of freedom and speculated that this may be related to an embedding into a context that correlates internal and external variables such as string theory. In this short note, I point out another symmetry possessed by all the colour evolution anomalous dimension matrices calculated to date. It is more prosaic, but equally unexpected, and may also point to the fact that colour evolution might be understood in some deeper theoretical framework. To my knowledge it has not been pointed out elsewhere, or anticipated by any of the authors calculating these matrices. It is simply that, in a suitably chosen colour basis, they are complex symmetric matrices

[Evolution of education in nursing].

Science.gov (United States)

Clavijo Chamorro, María Zoraida; Romero de Julián, Francisco Javier; Paniagua Vivas, María Sandra

2016-07-26

This study focuses on investigating the evolution of nursing studies in order to know how much this transformation has contributed to the development of the nursing profession. Literature review with data sources from different national and international databases. These sources provide an update on the ongoing evolution of nursing studies and the progress of this profession as a result of change. The competencies and skills that add value to the nursing profession are: an evidence-based practice; empathic communication; and other broad-range skills such as critical thinking. All are necessary in order to develop the profession alongside the constant changes in the health systems and the improvement of quality care. These competencies and skills should be evaluated and their achievement is being reached through the "portfolio". Innovations that enable the development of these skills can be found in education, strategies and tools used by educators and institutions.

The Life Review in Five Short Stories about Characters Facing Death.

Science.gov (United States)

Nicholl, Grier

1985-01-01

Uses five modern short stories about people facing death to illustrate and connect various observations of and theories about the dying process developed by Elisabeth Kubler-Ross and Robert N. Butler. In response to the imminence of their deaths, the characters survey their past, attempting to reintegrate their life's experiences. (JAC)

Historical review

International Nuclear Information System (INIS)

Zamora C, H.H.

1989-01-01

Short history of the ''Instituto de Asuntos Nucleares''. A short historical review about IAN is made: from 1956 when it was called Instituto Colombiano de Asuntos Nucleares, showing its scientific and technical development and the most important events that have occurred in the last 30 years. The people who had contributed to the progress of the institution are also considered, making emphasis in the important happenings that have guided the routes of the IAN

Evidence for widespread convergent evolution around human microsatellites.

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Edward J Vowles

2004-08-01

Full Text Available Microsatellites are a major component of the human genome, and their evolution has been much studied. However, the evolution of microsatellite flanking sequences has received less attention, with reports of both high and low mutation rates and of a tendency for microsatellites to cluster. From the human genome we generated a database of many thousands of (AC(n flanking sequences within which we searched for common characteristics. Sequences flanking microsatellites of similar length show remarkable levels of convergent evolution, indicating shared mutational biases. These biases extend 25-50 bases either side of the microsatellite and may therefore affect more than 30% of the entire genome. To explore the extent and absolute strength of these effects, we quantified the observed convergence. We also compared homologous human and chimpanzee loci to look for evidence of changes in mutation rate around microsatellites. Most models of DNA sequence evolution assume that mutations are independent and occur randomly. Allowances may be made for sites mutating at different rates and for general mutation biases such as the faster rate of transitions over transversions. Our analysis suggests that these models may be inadequate, in that proximity to even very short microsatellites may alter the rate and distribution of mutations that occur. The elevated local mutation rate combined with sequence convergence, both of which we find evidence for, also provide a possible resolution for the apparently contradictory inferences of mutation rates in microsatellite flanking sequences.

Quality of rearing practices as predictor of short-term outcome in adolescent anorexia nervosa.

Science.gov (United States)

Castro, J; Toro, J; Cruz, M

2000-01-01

Studies of family relationships in anorexia nervosa have produced conflicting results. Some authors claim that family factors are related to short-term outcomes. Perceived rearing practices, as measured by the EMBU (Egna Minnen Betraffande Uppfostran: 'My memories of Upbringing') were examined in a sample (N = 158) of adolescents with anorexia nervosa and compared with the perceptions of adolescents (N = 159) from the general population. A further comparison was made between the groups of patients with good and bad short-term outcomes. Logistic regression analysis was performed to evaluate the predictive value of different variables on short-term outcome. Overall, small differences were observed in the perceptions of rearing practices as expressed by the controls and the anorexic patients. Patients with bad short-term outcome perceived more rejection and control-overprotection from both parents than those with good outcome. In the logistic regression analysis only Rejection from father and the EAT (Eating Attitudes Test) total score gave independent prediction of treatment response. Taken as a whole, these results do not support the idea of altered rearing practices in anorexic patients, at least in young patients with a short evolution of the disease. Perceived rearing practices, especially 'rejection', appear to have an appreciable effect on the short-term outcome.

An Empirical LTE Smartphone Power Model with a View to Energy Efficiency Evolution

DEFF Research Database (Denmark)

Lauridsen, Mads; Noël, Laurent; Sørensen, Troels Bundgaard

2014-01-01

measurements made on state-of-the-art LTE smartphones. Discontinuous Reception (DRX) sleep mode is also modeled, because it is one of the most effective methods to improve smartphone battery life. Energy efficiency has generally improved with each Radio Access Technology (RAT) generation, and to see......Smartphone users struggle with short battery life, and this affects their device satisfaction level and usage of the network. To evaluate how chipset manufacturers and mobile network operators can improve the battery life, we propose a Long Term Evolution (LTE) smartphone power model. The idea...... this evolution, we compare the energy efficiency of the latest LTE devices with devices based on Enhanced Data rates for GSM Evolution (EDGE), High Speed Packet Access (HSPA), and Wi-Fi*. With further generations of RAT systems we expect further improvements. To this end, we discuss the new LTE features, Carrier...

Evolution of short cognitive test performance in stroke patients with vascular cognitive impairment and vascular dementia: Baseline evaluation and follow-up

Science.gov (United States)

Custodio, Nilton; Montesinos, Rosa; Lira, David; Herrera-Perez, Eder; Bardales, Yadira; Valeriano-Lorenzo, Lucia

2017-01-01

ABSTRACT. There is limited evidence about the progression of cognitive performance during the post-stroke stage. Objective: To assess the evolution of cognitive performance in stroke patients without vascular cognitive impairment (VCI), patients with vascular mild cognitive impairment (MCI), and patients with vascular dementia (VD). Methods: A prospective cohort of stroke outpatients from two secondary medical centers in Lima, Peru was studied. We performed standardized evaluations at definitive diagnosis (baseline evaluation), and control follow-ups at 6 and 12 months, including a battery of short cognitive tests: Clinical Dementia Rating (CDR), Addenbrooke's Cognitive Examination (ACE), and INECO Frontal Screening (IFS). Results: 152 outpatients completed the follow-up, showing progressive increase in mean score on the CDR(0.34 to 0.46), contrary to the pattern observed on the ACE and IFS (78.18 to 76.48 and 23.63 to 22.24). The box plot for the CDR test showed that VCI patients had progressive worsening (0.79 to 0.16). Conversely, this trend was not observed in subjects without VCI. The box plot for the ACE and IFS showed that, for the majority of the differentiated stroke types, both non-VCI and VCI patients had progressive worsening. Conclusion: According to both ACE and IFS results during a 1-year follow-up, the cognitive performance of stroke patients worsened, a trend which was particularly consistent in infarction-type stroke patients. PMID:29354218

Evolution of short cognitive test performance in stroke patients with vascular cognitive impairment and vascular dementia: Baseline evaluation and follow-up

Directory of Open Access Journals (Sweden)

Nilton Custodio

Full Text Available ABSTRACT. There is limited evidence about the progression of cognitive performance during the post-stroke stage. Objective: To assess the evolution of cognitive performance in stroke patients without vascular cognitive impairment (VCI, patients with vascular mild cognitive impairment (MCI, and patients with vascular dementia (VD. Methods: A prospective cohort of stroke outpatients from two secondary medical centers in Lima, Peru was studied. We performed standardized evaluations at definitive diagnosis (baseline evaluation, and control follow-ups at 6 and 12 months, including a battery of short cognitive tests: Clinical Dementia Rating (CDR, Addenbrooke's Cognitive Examination (ACE, and INECO Frontal Screening (IFS. Results: 152 outpatients completed the follow-up, showing progressive increase in mean score on the CDR(0.34 to 0.46, contrary to the pattern observed on the ACE and IFS (78.18 to 76.48 and 23.63 to 22.24. The box plot for the CDR test showed that VCI patients had progressive worsening (0.79 to 0.16. Conversely, this trend was not observed in subjects without VCI. The box plot for the ACE and IFS showed that, for the majority of the differentiated stroke types, both non-VCI and VCI patients had progressive worsening. Conclusion: According to both ACE and IFS results during a 1-year follow-up, the cognitive performance of stroke patients worsened, a trend which was particularly consistent in infarction-type stroke patients.

Evolution of hemostatic agents in surgical practice

Directory of Open Access Journals (Sweden)

Chandru P Sundaram

2010-01-01

Conclusions : A review of the evolution of topical hemostatic agents highlights opportunities for potential novel research. Fibrin sealants may have the most opportunity for advancement, and understanding the history of these products is useful. With the drive in urology for minimally invasive surgical techniques, adaptation of topical hemostatic agents to this surgical approach would be valuable and offers an opportunity for novel contributions.

Variable amplitude fatigue crack growth behavior - a short overview

International Nuclear Information System (INIS)

Singh, Konjengbam Darunkumar; Parry, Matthew Roger; Sinclair, Ian

2011-01-01

A short overview concerning variable amplitude (VA) fatigue crack growth behavior is presented in this paper. The topics covered in this review encompass important issues pertaining to both single and repeated overload transients. Reviews on transient post overload effects such as plasticity induced crack closure, crack tip blunting, residual stresses, crack deflection and branching, activation of near threshold mechanisms, strain hardening are highlighted. A brief summary on experimental trends and finite element modelling of overload induced crack closure is also presented

Variable amplitude fatigue crack growth behavior - a short overview

Energy Technology Data Exchange (ETDEWEB)

Singh, Konjengbam Darunkumar [Indian Institute of Technology, Guwahati (India); Parry, Matthew Roger [Airbus Operations Ltd, Bristol (United Kingdom); Sinclair, Ian [University of Southampton, Southampton (United Kingdom)

2011-03-15

A short overview concerning variable amplitude (VA) fatigue crack growth behavior is presented in this paper. The topics covered in this review encompass important issues pertaining to both single and repeated overload transients. Reviews on transient post overload effects such as plasticity induced crack closure, crack tip blunting, residual stresses, crack deflection and branching, activation of near threshold mechanisms, strain hardening are highlighted. A brief summary on experimental trends and finite element modelling of overload induced crack closure is also presented.

A compact introduction to evolution at small x and the Color Glass Condensate

Science.gov (United States)

Weigert, Heribert

2007-02-01

The Color Glass Condensate has become an important tool to understand saturation phenomena in high energy collisions involving large nuclei. The following provides a short introduction into the main ideas and theoretical tools used to describe saturation effects at high energies; in particular the nonlinear evolution equations and scaling phenomena in terms of the saturation scale Qs.

Review of design codes of concrete encased steel short columns under axial compression

Directory of Open Access Journals (Sweden)

K.Z. Soliman

2013-08-01

Full Text Available In recent years, the use of encased steel concrete columns has been increased significantly in medium-rise or high-rise buildings. The aim of the present investigation is to assess experimentally the current methods and codes for evaluating the ultimate load behavior of concrete encased steel short columns. The current state of design provisions for composite columns from the Egyptian codes ECP203-2007 and ECP-SC-LRFD-2012, as well as, American Institute of Steel Construction, AISC-LRFD-2010, American Concrete Institute, ACI-318-2008, and British Standard BS-5400-5 was reviewed. The axial capacity portion of both the encased steel section and the concrete section was also studied according to the previously mentioned codes. Ten encased steel concrete columns have been investigated experimentally to study the effect of concrete confinement and different types of encased steel sections. The measured axial capacity of the tested ten composite columns was compared with the values calculated by the above mentioned codes. It is concluded that non-negligible discrepancies exist between codes and the experimental results as the confinement effect was not considered in predicting both the strength and ductility of concrete. The confining effect was obviously influenced by the shape of the encased steel section. The tube-shaped steel section leads to better confinement than the SIB section. Among the used codes, the ECP-SC-LRFD-2012 led to the most conservative results.

Enhanced stability of car-following model upon incorporation of short-term driving memory

Science.gov (United States)

Liu, Da-Wei; Shi, Zhong-Ke; Ai, Wen-Huan

2017-06-01

Based on the full velocity difference model, a new car-following model is developed to investigate the effect of short-term driving memory on traffic flow in this paper. Short-term driving memory is introduced as the influence factor of driver's anticipation behavior. The stability condition of the newly developed model is derived and the modified Korteweg-de Vries (mKdV) equation is constructed to describe the traffic behavior near the critical point. Via numerical method, evolution of a small perturbation is investigated firstly. The results show that the improvement of this new car-following model over the previous ones lies in the fact that the new model can improve the traffic stability. Starting and breaking processes of vehicles in the signalized intersection are also investigated. The numerical simulations illustrate that the new model can successfully describe the driver's anticipation behavior, and that the efficiency and safety of the vehicles passing through the signalized intersection are improved by considering short-term driving memory.

The evolution of transmission mode

Science.gov (United States)

Forbes, Mark R.; Hauffe, Heidi C.; Kallio, Eva R.; Okamura, Beth; Sait, Steven M.

2017-01-01

This article reviews research on the evolutionary mechanisms leading to different transmission modes. Such modes are often under genetic control of the host or the pathogen, and often in conflict with each other via trade-offs. Transmission modes may vary among pathogen strains and among host populations. Evolutionary changes in transmission mode have been inferred through experimental and phylogenetic studies, including changes in transmission associated with host shifts and with evolution of the unusually complex life cycles of many parasites. Understanding the forces that determine the evolution of particular transmission modes presents a fascinating medley of problems for which there is a lack of good data and often a lack of conceptual understanding or appropriate methodologies. Our best information comes from studies that have been focused on the vertical versus horizontal transmission dichotomy. With other kinds of transitions, theoretical approaches combining epidemiology and population genetics are providing guidelines for determining when and how rapidly new transmission modes may evolve, but these are still in need of empirical investigation and application to particular cases. Obtaining such knowledge is a matter of urgency in relation to extant disease threats. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289251

Evolution caused by extreme events.

Science.gov (United States)

Grant, Peter R; Grant, B Rosemary; Huey, Raymond B; Johnson, Marc T J; Knoll, Andrew H; Schmitt, Johanna

2017-06-19

Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic (pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

Evolution and classification of the CRISPR-Cas systems

Science.gov (United States)

S. Makarova, Kira; H. Haft, Daniel; Barrangou, Rodolphe; J. J. Brouns, Stan; Charpentier, Emmanuelle; Horvath, Philippe; Moineau, Sylvain; J. M. Mojica, Francisco; I. Wolf, Yuri; Yakunin, Alexander F.; van der Oost, John; V. Koonin, Eugene

2012-01-01

The CRISPR–Cas (clustered regularly interspaced short palindromic repeats–CRISPR-associated proteins) modules are adaptive immunity systems that are present in many archaea and bacteria. These defence systems are encoded by operons that have an extraordinarily diverse architecture and a high rate of evolution for both the cas genes and the unique spacer content. Here, we provide an updated analysis of the evolutionary relationships between CRISPR–Cas systems and Cas proteins. Three major types of CRISPR–Cas system are delineated, with a further division into several subtypes and a few chimeric variants. Given the complexity of the genomic architectures and the extremely dynamic evolution of the CRISPR–Cas systems, a unified classification of these systems should be based on multiple criteria. Accordingly, we propose a `polythetic' classification that integrates the phylogenies of the most common cas genes, the sequence and organization of the CRISPR repeats and the architecture of the CRISPR–cas loci. PMID:21552286

Massage therapy has short-term benefits for people with common musculoskeletal disorders compared to no treatment: a systematic review.

Science.gov (United States)

Bervoets, Diederik C; Luijsterburg, Pim A J; Alessie, Jeroen J N; Buijs, Martijn J; Verhagen, Arianne P

2015-07-01

Is massage therapy effective for people with musculoskeletal disorders compared to any other treatment or no treatment? Systematic review of randomised clinical trials. People with musculoskeletal disorders. Massage therapy (manual manipulation of the soft tissues) as a stand-alone intervention. The primary outcomes were pain and function. The 26 eligible randomised trials involved 2565 participants. The mean sample size was 95 participants (range 16 to 579) per study; 10 studies were considered to be at low risk of bias. Overall, low-to-moderate-level evidence indicated that massage reduces pain in the short term compared to no treatment in people with shoulder pain and osteoarthritis of the knee, but not in those with low back pain or neck pain. Furthermore, low-to-moderate-level evidence indicated that massage improves function in the short term compared to no treatment in people with low back pain, knee arthritis or shoulder pain. Low-to-very-low-level evidence from single studies indicated no clear benefits of massage over acupuncture, joint mobilisation, manipulation or relaxation therapy in people with fibromyalgia, low back pain and general musculoskeletal pain. Massage therapy, as a stand-alone treatment, reduces pain and improves function compared to no treatment in some musculoskeletal conditions. When massage is compared to another active treatment, no clear benefit was evident. Copyright © 2015 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Delegation to automaticity: the driving force for cognitive evolution?

Science.gov (United States)

Shine, J M; Shine, R

2014-01-01

The ability to delegate control over repetitive tasks from higher to lower neural centers may be a fundamental innovation in human cognition. Plausibly, the massive neurocomputational challenges associated with the mastery of balance during the evolution of bipedality in proto-humans provided a strong selective advantage to individuals with brains capable of efficiently transferring tasks in this way. Thus, the shift from quadrupedal to bipedal locomotion may have driven the rapid evolution of distinctive features of human neuronal functioning. We review recent studies of functional neuroanatomy that bear upon this hypothesis, and identify ways to test our ideas.

Evolution of the solar 'constant'

Energy Technology Data Exchange (ETDEWEB)

Newman, M J

1980-06-01

Variations in solar luminosity over geological time are discussed in light of the effect of the solar constant on the evolution of life on earth. Consideration is given to long-term (5 - 7% in a billion years) increases in luminosity due to the conversion of hydrogen into helium in the solar interior, temporary enhancements to solar luminosity due to the accretion of matter from the interstellar medium at intervals on the order of 100 million years, and small-amplitude rapid fluctuations of luminosity due to the stochastic nature of convection on the solar surface. It is noted that encounters with dense interstellar clouds could have had serious consequences for life on earth due to the peaking of the accretion-induced luminosity variation at short wavelengths.

Evolution of streamer groups in nonthermal plasma

Energy Technology Data Exchange (ETDEWEB)

Okubo, M., E-mail: mokubo@me.osakafu-u.ac.jp [Department of Mechanical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531 (Japan)

2015-12-15

Nonthermal plasmas (NTPs) induced by atmospheric nanosecond pulsed corona discharge have been studied for controlling pollution from combustors, such as boilers, incinerators, and diesel engines. In high-speed short-width high-voltage pulsed corona discharge-induced plasmas, primary streamer evolution is followed by secondary streamer evolution. Though this phenomenon is known experimentally, the details of the structures of the streamers and their evolution mechanisms have not been fully clarified. In this letter, we perform quasi two-dimensional numerical analysis of nonequilibrium NTP induced by a nanosecond positive pulsed corona discharge. The continuum fluid equations for two-temperature nonequilibrium NTP are used as governing equations. In this study, 197 gas phase reactions for 25 chemical species and 21 surface reactions on the inner glass wall surface are considered in an air plasma under atmospheric pressure. The simulated behavior of the streamer groups agrees with experimental observations. Soon after the voltage increases on the reactor, primary streamers are formed, which may transit the complete gap, disappearing near the peak voltage. Next, second streamers appear, disappearing at the end of the applied voltage pulse. The streamer wavelength and the distance between the streamers in the axial direction are determined. Moreover, ozone generation is shown to be more significant in the secondary streamer. This simulation will allow better predictions for nanosecond positive pulsed plasma systems.

Evolution of streamer groups in nonthermal plasma

Science.gov (United States)

Okubo, M.

2015-12-01

Nonthermal plasmas (NTPs) induced by atmospheric nanosecond pulsed corona discharge have been studied for controlling pollution from combustors, such as boilers, incinerators, and diesel engines. In high-speed short-width high-voltage pulsed corona discharge-induced plasmas, primary streamer evolution is followed by secondary streamer evolution. Though this phenomenon is known experimentally, the details of the structures of the streamers and their evolution mechanisms have not been fully clarified. In this letter, we perform quasi two-dimensional numerical analysis of nonequilibrium NTP induced by a nanosecond positive pulsed corona discharge. The continuum fluid equations for two-temperature nonequilibrium NTP are used as governing equations. In this study, 197 gas phase reactions for 25 chemical species and 21 surface reactions on the inner glass wall surface are considered in an air plasma under atmospheric pressure. The simulated behavior of the streamer groups agrees with experimental observations. Soon after the voltage increases on the reactor, primary streamers are formed, which may transit the complete gap, disappearing near the peak voltage. Next, second streamers appear, disappearing at the end of the applied voltage pulse. The streamer wavelength and the distance between the streamers in the axial direction are determined. Moreover, ozone generation is shown to be more significant in the secondary streamer. This simulation will allow better predictions for nanosecond positive pulsed plasma systems.

Optimization using quantum mechanics: quantum annealing through adiabatic evolution

International Nuclear Information System (INIS)

Santoro, Giuseppe E; Tosatti, Erio

2006-01-01

We review here some recent work in the field of quantum annealing, alias adiabatic quantum computation. The idea of quantum annealing is to perform optimization by a quantum adiabatic evolution which tracks the ground state of a suitable time-dependent Hamiltonian, where 'ℎ' is slowly switched off. We illustrate several applications of quantum annealing strategies, starting from textbook toy-models-double-well potentials and other one-dimensional examples, with and without disorder. These examples display in a clear way the crucial differences between classical and quantum annealing. We then discuss applications of quantum annealing to challenging hard optimization problems, such as the random Ising model, the travelling salesman problem and Boolean satisfiability problems. The techniques used to implement quantum annealing are either deterministic Schroedinger's evolutions, for the toy models, or path-integral Monte Carlo and Green's function Monte Carlo approaches, for the hard optimization problems. The crucial role played by disorder and the associated non-trivial Landau-Zener tunnelling phenomena is discussed and emphasized. (topical review)

Abundance gradients in disc galaxies and chemical evolution models

International Nuclear Information System (INIS)

Diaz, A.I.

1989-01-01

The present state of abundance gradients and chemical evolution models of spiral galaxies is reviewed. An up to date compilation of abundance data in the literature concerning HII regions over galactic discs is presented. From these data Oxygen and Nitrogen radial gradients are computed. The slope of the Oxygen gradient is shown to have a break at a radius between 1.5 and 1.75 times the value of the effective radius of the disc, i.e. the radius containing half of the light of the disc. The gradient is steeper in the central parts of the disc and becomes flatter in the outer parts. N/O gradients are shown to be rather different from galaxy to galaxy and only a weak trend of N/O with O/H is found. The existing chemical evolution models for spiral galaxies are reviewed with special emphasis in the interpretation of numerical models having a large number of parameters. (author)

The Evolution of Photosynthesis

International Nuclear Information System (INIS)

Broda, E.

1976-01-01

This Review was written by Engelbert Broda, an Austrian Chemist and Physicist, on February the 10th 1976. The merits of the inductive and the deductive approach in tracing the pathways of evolution are discussed. Using the latter approach, it is concluded that photosynthesis followed fermentation as a method of obtaining energy-rich compounds, especially ATP. Photosynthesis probably arose by utilization of membranes for bioenergetic processes. Originally photosynthesis served photophosphorylation (ATP production), later reducing power was also made, either by open-ended, light-powered, electron flow or driven by ATP; ultimate electron donors were at first hydrogen or sulfur compounds, and later water, the last-named capability Was acquired by prokaryotic algae the earliest plants, similar to the recent blue-greens. When free oxygen entered the atmosphere for the first time, various forms of respiration (oxidative phosphorylation) became possible. Mechanistically, respiration evolved from photosynthesis (‘conversion hypotheses’). Prokaryotic algae are probably the ancestors of the chloroplasts in the eukaryotes, In the evolution of the eukaryotes, not much change in the basic processes of photosynthesis occurred.(author)

Relations between the galactic evolution and the stellar evolution

International Nuclear Information System (INIS)

Audouze, J.

1984-01-01

After a quick definition of the galactic evolution and a summary of the basic ingredients (namely the abundances of the chemical elements observed in different astrophysical sites), the parameters directly related to the stellar evolution which govern the galactic evolution are outlined. They are the rates of star formation, the initial mass functions and the various nucleosynthetic yields. The 'classical' models of chemical evolution of galaxies are then briefly recalled. Finally, attention is drawn to three recent contributions concerning both the galactic evolution and the stellar evolution. They are (i) some prediction of the rate of star formation for low mass stars made from the planetary nebula abundance distribution (ii) the chemical evolution of C, O and Fe and (iii) the chemical evolution of the galactic interstellar medium. (Auth.)

Short review of high-pressure crystal growth and magnetic and electrical properties of solid-state osmium oxides

Energy Technology Data Exchange (ETDEWEB)

Yamaura, Kazunari, E-mail: YAMAURA.Kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810 (Japan)

2016-04-15

High-pressure crystal growth and synthesis of selected solid-state osmium oxides, many of which are perovskite-related types, are briefly reviewed, and their magnetic and electrical properties are introduced. Crystals of the osmium oxides, including NaOsO{sub 3}, LiOsO{sub 3}, and Na{sub 2}OsO{sub 4}, were successfully grown under high-pressure and high-temperature conditions at 6 GPa in the presence of an appropriate amount of flux in a belt-type apparatus. The unexpected discovery of a magnetic metal–insulator transition in NaOsO{sub 3}, a ferroelectric-like transition in LiOsO{sub 3}, and high-temperature ferrimagnetism driven by a local structural distortion in Ca{sub 2}FeOsO{sub 6} may represent unique features of the osmium oxides. The high-pressure and high-temperature synthesis and crystal growth has played a central role in the development of solid-state osmium oxides and the elucidation of their magnetic and electronic properties toward possible use in multifunctional devices. - Graphical Abstract: Flux-grown crystals of NaOsO{sub 3} under high-pressure and high-temperature conditions in a belt-type apparatus. The crystal shows a magnetically driven metal–insulator transition at a temperature of 410 K. - Highlights: • Short review of high-pressure crystal growth of solid-state osmium oxides. • Wide variety of magnetic properties of solid-state osmium oxides. • Perovskite and related dense structures stabilized at 3–17 GPa.

Total Quality Management in Libraries: A Short Review

Directory of Open Access Journals (Sweden)

Erol Yılmaz

2013-11-01

Full Text Available Total Quality Management (TQM, is a management style that aimed at customer satisfaction. In the organisations in which TQM is applied customer is in the centre of the organization. In other words, in this kind of organisations the customer comes before everything else. Reaching the highest level of the customer satisfaction is among the targets of the mentioned organizations. In this study, primarily, definition of the TQM is going to be made together with its definition, short history, purpose, benefits and factors; besides descriptive information is going to be given about internal customer, external customer, customer centered process and customer satisfaction. In the second part of the study, TQM subject is going to be discussed within the scope of the libraries widely. In this context, after explanation of customer centeredness (placing the customer at the centre, customer satisfaction and benefits of the TQM to the libraries, the subject is going to be discussed in the context of our country.

The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: A systematic review.

Science.gov (United States)

Grgic, Jozo; Lazinica, Bruno; Mikulic, Pavle; Krieger, James W; Schoenfeld, Brad Jon

2017-09-01

Although the effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy have been investigated in several studies, the findings are equivocal and the practical implications remain unclear. In an attempt to provide clarity on the topic, we performed a systematic literature search of PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Physiotherapy Evidence Database (PEDro) electronic databases. Six studies were found to have met the inclusion criteria: (a) an experimental trial published in an English-language peer-reviewed journal; (b) the study compared the use of short (≤60 s) to long (>60 s) inter-set rest intervals in a traditional dynamic resistance exercise using both concentric and eccentric muscle actions, with the only difference in resistance training among groups being the inter-set rest interval duration; (c) at least one method of measuring changes in muscle mass was used in the study; (d) the study lasted for a minimum of four weeks, employed a training frequency of ≥2 resistance training days per week, and (e) used human participants without known chronic disease or injury. Current evidence indicates that both short and long inter-set rest intervals may be useful when training for achieving gains in muscle hypertrophy. Novel findings involving trained participants using measures sensitive to detect changes in muscle hypertrophy suggest a possible advantage for the use of long rest intervals to elicit hypertrophic effects. However, due to the paucity of studies with similar designs, further research is needed to provide a clear differentiation between these two approaches.

Recent advances on the formation and evolution of white dwarfs

International Nuclear Information System (INIS)

Sion, E.M.

1986-01-01

Advances made in the past seven years in both the theory and observation of white dwarfs which have led to major progress in understanding white dwarf formation and evolution are reviewed. The roles of convective dredge-up, mixing and dilution, accretion, gravitational and thermal diffusion in dense plasmas, radiate forces and mass outflow, nuclear shell burning, diffusion-induced reactions, late thermonuclear shell flashes, rotation, and magnetic fields in white dwarf evolution are considered. Recent work on the properties of white dwarfs in cataclysmic variables is briefly addressed. 153 references

Decay properties of short-lived mass-separated fission products

International Nuclear Information System (INIS)

Lund, E.

1977-01-01

The present work describes determinations of total β-decay energies and studies of delayed neutron emission including the identification and half-life determinations of delayed neutron precursors and the measurement of neutron spectra. It also includes a short review of the OSIRIS on-line isotope separator facility. (Auth.)

The evolution of plant-insect mutualisms.

Science.gov (United States)

Bronstein, Judith L; Alarcón, Ruben; Geber, Monica

2006-01-01

Mutualisms (cooperative interactions between species) have had a central role in the generation and maintenance of life on earth. Insects and plants are involved in diverse forms of mutualism. Here we review evolutionary features of three prominent insect-plant mutualisms: pollination, protection and seed dispersal. We focus on addressing five central phenomena: evolutionary origins and maintenance of mutualism; the evolution of mutualistic traits; the evolution of specialization and generalization; coevolutionary processes; and the existence of cheating. Several features uniting very diverse insect-plant mutualisms are identified and their evolutionary implications are discussed: the involvement of one mobile and one sedentary partner; natural selection on plant rewards; the existence of a continuum from specialization to generalization; and the ubiquity of cheating, particularly on the part of insects. Plant-insect mutualisms have apparently both arisen and been lost repeatedly. Many adaptive hypotheses have been proposed to explain these transitions, and it is unlikely that any one of them dominates across interactions differing so widely in natural history. Evolutionary theory has a potentially important, but as yet largely unfilled, role to play in explaining the origins, maintenance, breakdown and evolution of insect-plant mutualisms.

Measuring Short-term Energy Security

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Ensuring energy security has been at the centre of the IEA mission since its inception, following the oil crises of the early 1970s. While the security of oil supplies remains important, contemporary energy security policies must address all energy sources and cover a comprehensive range of natural, economic and political risks that affect energy sources, infrastructures and services. In response to this challenge, the IEA is currently developing a Model Of Short-term Energy Security (MOSES) to evaluate the energy security risks and resilience capacities of its member countries. The current version of MOSES covers short-term security of supply for primary energy sources and secondary fuels among IEA countries. It also lays the foundation for analysis of vulnerabilities of electricity and end-use energy sectors. MOSES contains a novel approach to analysing energy security, which can be used to identify energy security priorities, as a starting point for national energy security assessments and to track the evolution of a country's energy security profile. By grouping together countries with similar 'energy security profiles', MOSES depicts the energy security landscape of IEA countries. By extending the MOSES methodology to electricity security and energy services in the future, the IEA aims to develop a comprehensive policy-relevant perspective on global energy security. This Brochure provides and overview of the analysis and results. Readers interested in an in-depth discussion of methodology are referred to the MOSES Working Paper.

A review on the Holocene evolution of an inner-shelf mud deposit in the southeastern Yellow Sea: the Huksan Mud Belt

Science.gov (United States)

Lee, Hee Jun

2015-12-01

The Huksan Mud Belt (HMB) has been extensively investigated with respect to its source and evolution since the 1980s. Studies on sediment budget or accumulation rates suggested two different origins, Korean and combined Korean and Chinese. However, neither of the suggested origins appears reliable because they were based on insufficient or inaccurate datasets on the basic sedimentological characteristics of the HMB. Although a major mud transport was inferred to be closely associated with either the Korean Coastal Current or the Yellow Sea Warm Current, their physical characters during the Holocene transgression have been rarely hind-casted thus far. The majority of studies on high-resolution seismic stratigraphy along with core log have suggested that the HMB stratigraphy consists of two units divided by an erosional boundary. The lower unit is further divided into two subunits by a subtle discontinuity that is laterally correlated with the erosional boundary. In line with the stratigraphy, the studies theorized that the erosion of the HMB had produced a re-deposited distal lobe, the younger lower subunit. In addition, this lobe was inferred to have prograded rapidly during the relatively short period of 6,500-5,500 yr B.P. Although the time interval of the erosion coincides with the decelerating rise in sea level, the hydrodynamic cause and effect of the erosion remain inexplicable. Therefore, the source and evolution of the HMB continue to be controversial, due largely to poor understanding of the paleo-physical oceanography of the Yellow Sea during the Holocene.

Short stature in children: Pattern and frequency in a pediatric clinic, Riyadh, Saudi Arabia.

Science.gov (United States)

Al-Jurayyan N, Nasir A; Mohamed, Sarar H; Al Otaibi, Hessah M; Al Issa, Sharifah T; Omer, Hala G

2012-01-01

Longitudinal growth assessment is essential in child care. Short stature can be promptly recognized only with accurate measurements of growth and critical analysis of growth data. The objective of this study was to determine the pattern of short stature among patients referred to an endocrine pediatric clinic, King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia and to ascertain the aetiological profile of short stature. This is a retrospective review of patients referred to a pediatric endocrine clinic with short stature during the period January 1990 and December 2009. After a proper detailed medical history, growth analysis and physical examination, followed by a radiological (bone age) and laboratory screening (complete blood count and thyroid function). Growth hormone stimulation tests were performed when indicated. Magnetic resonance imaging (MRI) of the pituitary was performed when necessary. As well, celiac screening and small bowel biopsy were performed when appropriate. During the period under review, hundred and ten patients were evaluated for short stature. Their age ranged from 2 years and six months to 4 years. The male to female ratio was 1.3:1. The commonest etiology was genetic short stature found in 57 (51.8%) patients, while in the other 53 (48.2%) patients, variable endocrine and nutritional causes were noted. Short stature was a common referral. A wide variety of etiological diagnosis was noticed with genetic short stature being the commonest. A wide variety of endocrine causes were evident, with growth hormone deficiency, as a results of different etiologies, being the commonest.

The evolution of offensive realism.

Science.gov (United States)

Johnson, Dominic D P; Phil, D; Thayer, Bradley A

Offensive realism, a theory of international relations, holds that states are disposed to competition and conflict because they are self-interested, power maximizing, and fearful of other states. Moreover, it argues that states are obliged to behave this way because doing so favors survival in the international system. Debate continues as to whether modern states actually do, or should, behave in this way, but we are struck by a different question. In this article, we ask whether the three core assumptions about behavior in offensive realism-self-help, power maximization, and outgroup fear-have any basis in scientific knowledge about human behavioral evolution. We find that these precise traits are not only evolutionarily adaptive but also empirically common across the animal kingdom, especially in primate and human societies. Based on these findings, we hypothesize that states behave as offensive realists predict not just because of anarchy in the modern international system but also because of the legacy of our evolution. In short, offensive realism may really be describing the nature of the human species more than the nature of the international system. If our hypothesis is correct, then evolutionary theory offers the following: (1) a novel ultimate cause of offensive realist behavior; (2) an extension of offensive realism to any domain in which humans compete for power; and (3) an explanation for why individual leaders themselves, and not just states, seek power. However, a key insight from evolution is that the primacy of self-help, power maximization, and outgroup fear does not necessarily condemn individuals or groups to competition and conflict; rather, these traits can in themselves give rise to cooperation and alliances.

Island universes structure and evolution of disk galaxies

CERN Document Server

DE JONG, R. S

2007-01-01

This book contains an up-to-date review of the structure and evolution of disk galaxies from both the observational and theoretical point of view. The book is the proceedings of the "Island Universes" conference held at the island of Terschelling, The Netherlands in July 2005, which attracted about 130 experts and students in the field. The conference was organized as a tribute to Dr. Piet C. van der Kruit for receiving the honorary Jacobus C. Kapteyn Professorship in Astronomy. The eight topical themes discussed at the meeting are reflected in these proceedings: 1) Properties of Stellar Disks, 2) Kinematics and Dynamics of Disk Galaxies, 3) Bars, Spiral Structure, and Secular Evolution in Disk Galaxies, 4) The Outskirts and Environment of Disk Galaxies, 5) Interstellar Matter, 6) (Evolution of) Star Formation in Galactic Disks, 7) Disk Galaxies through Cosmic Time, and 8) Formation Models of Disk Galaxies. These proceedings are concluded with a conference summary reflecting on the most significant recent pro...

Inverse scattering solution of non-linear evolution equations in one space dimension: an introduction

International Nuclear Information System (INIS)

Alvarez-Estrada, R.F.

1979-01-01

A comprehensive review of the inverse scattering solution of certain non-linear evolution equations of physical interest in one space dimension is presented. We explain in some detail the interrelated techniques which allow to linearize exactly the following equations: (1) the Korteweg and de Vries equation; (2) the non-linear Schrodinger equation; (3) the modified Korteweg and de Vries equation; (4) the Sine-Gordon equation. We concentrate in discussing the pairs of linear operators which accomplish such an exact linearization and the solution of the associated initial value problem. The application of the method to other non-linear evolution equations is reviewed very briefly

Remembering over the short-term: the case against the standard model.

Science.gov (United States)

Nairne, James S

2002-01-01

Psychologists often assume that short-term storage is synonymous with activation, a mnemonic property that keeps information in an immediately accessible form. Permanent knowledge is activated, as a result of on-line cognitive processing, and an activity trace is established "in" short-term (or working) memory. Activation is assumed to decay spontaneously with the passage of time, so a refreshing process-rehearsal-is needed to maintain availability. Most of the phenomena of immediate retention, such as capacity limitations and word length effects, are assumed to arise from trade-offs between rehearsal and decay. This "standard model" of how we remember over the short-term still enjoys considerable popularity, although recent research questions most of its main assumptions. In this chapter I review the recent research and identify the empirical and conceptual problems that plague traditional conceptions of short-term memory. Increasingly, researchers are recognizing that short-term retention is cue driven, much like long-term memory, and that neither rehearsal nor decay is likely to explain the particulars of short-term forgetting.

Early Stages of Microstructure and Texture Evolution during Beta Annealing of Ti-6Al-4V

Science.gov (United States)

Pilchak, A. L.; Sargent, G. A.; Semiatin, S. L.

2018-03-01

The early stages of microstructure evolution during annealing of Ti-6Al-4V in the beta phase field were established. For this purpose, a series of short-time heat treatments was performed using sheet samples that had a noticeable degree of alpha-phase microtexture in the as-received condition. Reconstruction of the beta-grain structure from electron-backscatter-diffraction measurements of the room-temperature alpha-phase texture revealed that microstructure evolution at short times was controlled not by general grain growth, but rather by nucleation-and-growth events analogous to discontinuous recrystallization. The nuclei comprised a small subset of beta grains that were highly misoriented relative to those comprising the principal texture component of the beta matrix. From a quantitative standpoint, the transformation kinetics were characterized by an Avrami exponent of approximately unity, thus suggestive of metadynamic recrystallization. The recrystallization process led to the weakening and eventual elimination of the initial beta texture through the growth of a population of highly misoriented grains.

Astrophysics a very short introduction

CERN Document Server

Binney, James

2016-01-01

Astrophysics is the physics of the stars, and more widely the physics of the Universe. It enables us to understand the structure and evolution of planetary systems, stars, galaxies, interstellar gas, and the cosmos as a whole. In this Very Short Introduction, the leading astrophysicist James Binney shows how the field of astrophysics has expanded rapidly in the past century, with vast quantities of data gathered by telescopes exploiting all parts of the electromagnetic spectrum, combined with the rapid advance of computing power, which has allowed increasingly effective mathematical modelling. He illustrates how the application of fundamental principles of physics - the consideration of energy and mass, and momentum - and the two pillars of relativity and quantum mechanics, has provided insights into phenomena ranging from rapidly spinning millisecond pulsars to the collision of giant spiral galaxies. This is a clear, rigorous introduction to astrophysics for those keen to cut their teeth on a conceptual trea...

Late stages of massive star evolution and nucleosynthesis

International Nuclear Information System (INIS)

Nomoto, Ken'ichi; Hashimoto, Masa-aki.

1986-01-01

The evolution of massive stars in the mass range of 8 to 25 M solar mass is reviewed. The effect of electron degeneracy on the gravothermal nature of stars is discussed. Depending on the stellar mass, the stars form three types of cores, namely, non-degenerate, semi-degenerate, and strongly degenerate cores. The evolution for these cases is quite distinct from each other and leads to the three different types of final fate. It is suggested that our helium star model, which is equivalent to a 25 M solar mass star, will form a relatively small mass iron core despite the faster 12 C(α,γ) 16 O reaction. 50 refs., 21 figs

Clostridium difficile infection: Evolution, phylogeny and molecular epidemiology.

Science.gov (United States)

Elliott, Briony; Androga, Grace O; Knight, Daniel R; Riley, Thomas V

2017-04-01

Over the recent decades, Clostridium difficile infection (CDI) has emerged as a global public health threat. Despite growing attention, C. difficile remains a poorly understood pathogen, however, the exquisite sensitivity offered by next generation sequencing (NGS) technology has enabled analysis of the genome of C. difficile, giving us access to massive genomic data on factors such as virulence, evolution, and genetic relatedness within C. difficile groups. NGS has also demonstrated excellence in investigations of outbreaks and disease transmission, in both small and large-scale applications. This review summarizes the molecular epidemiology, evolution, and phylogeny of C. difficile, one of the most important pathogens worldwide in the current antibiotic resistance era. Copyright © 2016 Elsevier B.V. All rights reserved.

Perinatally lethal short rib-polydactyly syndromes. Pt. 1

International Nuclear Information System (INIS)

Sillence, D.; Kozlowski, K.; Bar-ziv, J.; Fuhrmann-Rieger, A.; Fuhrmann, W.; Pascu, F.

1987-01-01

Thirteen newborns with lethal short rib-polydactyly (SRP) have been reviewed, 11 with SRP type 3 (Verma-Naumoff) and 2 with SRP tye 2 (Majewski). In the former group there were three sets of siblings. The excess of males with SRP type III (Verma-Naumoff) is confirmed in this present study. A high frequency of phenotypic females including sex-reversed constitutional males with SRP type 1 (Saldino-Noonan) is in marked contrast to these findings in SRP type 3. Possible hypotheses include variable expressivity in non-Majewski short rib-polydactyly syndromes with sex-reversed and constitutional female cases tending to show more severe phenotypic expression both in terms of major anomalies and skeletal dysplastic effects. (orig.)

Adult neurogenesis supports short-term olfactory memory.

Science.gov (United States)

Arenkiel, Benjamin R

2010-06-01

Adult neurogenesis has captivated neuroscientists for decades, with hopes that understanding the programs underlying this phenomenon may provide unique insight toward avenues for brain repair. Interestingly, however, despite intense molecular and cellular investigation, the evolutionary roles and biological functions for ongoing neurogenesis have remained elusive. Here I review recent work published in the Journal of Neuroscience that reveals a functional role for continued neurogenesis toward forming short-term olfactory memories.

The Longitudinal Evolution of Equatorial Coronal Holes

Science.gov (United States)

Krista, Larisza D.; McIntosh, Scott W.; Leamon, Robert J.

2018-04-01

In 2011, three satellites—the Solar-Terrestrial RElations Observatory A & B, and the Solar Dynamics Observatory (SDO)—were in a unique spatial alignment that allowed a 360° view of the Sun. This alignment lasted until 2014, the peak of solar cycle 24. Using extreme ultraviolet images and Hovmöller diagrams, we studied the lifetimes and propagation characteristics of coronal holes (CHs) in longitude over several solar rotations. Our initial results show at least three distinct populations of “low-latitude” or “equatorial” CHs (below 65^\\circ latitude). One population rotates in retrograde direction and coincides with a group of long-lived (over sixty days) CHs in each hemisphere. These are typically located between 30° and 55^\\circ , and display velocities of ∼55 m s‑1 slower than the local differential rotation rate. A second, smaller population of CHs rotate prograde, with velocities between ∼20 and 45 m s‑1. This population is also long-lived, but observed ±10° from the solar equator. A third population of CHs are short-lived (less than two solar rotations), and they appear over a wide range of latitudes (±65°) and exhibit velocities between ‑140 and 80 m s‑1. The CH “butterfly diagram” we developed shows a systematic evolution of the longer-lived holes; however, the sample is too short in time to draw conclusions about possible connections to dynamo-related phenomena. An extension of the present work to the 22 years of the combined SOHO–SDO archives is necessary to understand the contribution of CHs to the decadal-scale evolution of the Sun.

Short interspersed elements (SINEs) of the Geomyoidea superfamily rodents.

Science.gov (United States)

Gogolevsky, Konstantin P; Kramerov, Dmitri A

2006-05-24

A new short interspersed element (SINE) was isolated from the genome of desert kangaroo rat (Dipodomys deserti) using single-primer PCR. This SINE consists of two monomers: the left monomer (IDL) resembles rodent ID element and other tRNAAla(CGC)-derived SINEs, whereas the right one (Geo) shows no similarity with known SINE sequences. PCR and hybridization analyses demonstrated that IDL-Geo SINE is restricted to the rodent superfamily Geomyoidea (families Geomyidea and Heteromyidea). Isolation and analysis of IDL-Geo from California pocket mouse (Chaetodipus californicus) and Botta's pocket gopher (Thomomys bottae) revealed some species-specific features of this SINE family. The structure and evolution of known dimeric SINEs are discussed.

Short times and short distances in nuclear and particle physics: A pedagogical review

International Nuclear Information System (INIS)

West, G.B.

1988-01-01

The formalism relevant to deep inelastic processes in both non- relativistic and relativistic systems is reviewed with an emphasis on scaling and its violations. In the former case we show how a systematic expansion in 1/q 2 (q being the momentum transfer) can be derived which delineates the incoherent scattering from bound state and potential corrections. We demonstrate how this exact many-body non-relativistic formalism corresponds to the light-cone operator product expansion in quantum field theory. As examples, scaling in liquids, nuclei and nucleons is discussed with emphasis on the EMC effect, shadowing and the relationship to the photo absorption limit. 8 refs., 10 figs

Morphological approach of the sternal foramen: an anatomic study and a short review of the literature.

Science.gov (United States)

Gkantsinikoudis, N; Chaniotakis, C; Gkasdaris, G; Georgiou, N; Kapetanakis, S

2017-01-01

The sternal foramen (SF) constitutes a specific anatomic defect in sternum, indicating an impaired fusion of ossificated segments, which occurs either in an anatomical part of the sternum or in sternal joints. The aim of this article is to provide baseline statistical data about the variations of the SF, to present a short review of the relevant literature and to compare results with other studies and populations. We review relevant literature, and we present data obtai-ned from skeletal samples of known population and sex. A total of 35 well-preserved dried sterna from the prefecture of Eastern Macedonia and Thrace, Greece, were selected: 20 men and 15 women with a mean age of 55 ± 6 years old. Measurements were made with a sliding calliper and photographic documentation. The incidence of the SF in the 35 dried specimens was 14.2%, 4 men (20% of male sample) and 1 woman (6.6% of female sample) and 80% of sternal foramina were observed in male individuals. The SF was found in the sternum body (2 cases, 40% of foramina), in xiphoid process (2 cases, 40% of foramina) and in sternoxiphoidal junction (1 case, 20% of foramina). All of the sterna presented 1 single visible SF. Two anatomically unique cases were identified throughout these 5 sterna, both belonging in male subjects. The SF constitutes a relatively common variation with great radiological, clinical, and forensic significance. Presence of a SF with irregular bony margins complicates considerably radiological differential diagnosis. Awareness of this important anatomic variation is fundamental for clinicians and autopsy pathologists, in order to avoid severe fatal complications and elucidate the exact cause of death, respectively.

Fatigue Damage Evaluation of Short Carbon Fiber Reinforced Plastics Based on Phase Information of Thermoelastic Temperature Change.

Science.gov (United States)

Shiozawa, Daiki; Sakagami, Takahide; Nakamura, Yu; Nonaka, Shinichi; Hamada, Kenichi

2017-12-06

Carbon fiber-reinforced plastic (CFRP) is widely used for structural members of transportation vehicles such as automobile, aircraft, or spacecraft, utilizing its excellent specific strength and specific rigidity in contrast with the metal. Short carbon fiber composite materials are receiving a lot of attentions because of their excellent moldability and productivity, however they show complicated behaviors in fatigue fracture due to the random fibers orientation. In this study, thermoelastic stress analysis (TSA) using an infrared thermography was applied to evaluate fatigue damage in short carbon fiber composites. The distribution of the thermoelastic temperature change was measured during the fatigue test, as well as the phase difference between the thermoelastic temperature change and applied loading signal. Evolution of fatigue damage was detected from the distribution of thermoelastic temperature change according to the thermoelastic damage analysis (TDA) procedure. It was also found that fatigue damage evolution was more clearly detected than before by the newly developed thermoelastic phase damage analysis (TPDA) in which damaged area was emphasized in the differential phase delay images utilizing the property that carbon fiber shows opposite phase thermoelastic temperature change.

An updated systematic review of the evolution of ALPPS and evaluation of its advantages and disadvantages in accordance with current evidence.

Science.gov (United States)

Cai, Yu-Long; Song, Pei-Pei; Tang, Wei; Cheng, Nan-Sheng

2016-06-01

The main obstacle to achieving an R0 resection after a major hepatectomy is inability to preserve an adequate future liver remnant (FLR) to avoid postoperative liver failure (PLF). Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel technique for resecting tumors that were previously considered unresectable, and this technique results in a vast increase in the volume of the FLR in a short period of time. However, this technique continues to provoke heated debate because of its high mortality and morbidity.The evolution of ALPPS and its advantages and disadvantages have been systematically reviewed and evaluated in accordance with current evidence. Electronic databases (PubMed and Medline) were searched for potentially relevant articles from January 2007 to January 2016.ALPPS has evolved into various modified forms. Some of these modified techniques have reduced the difficulty of the procedure and enhanced its safety. Current evidence indicates that the advantages of ALPPS are rapid hypertrophy of the FLR, the feasibility of the procedure, and a higher rate of R0 resection in comparison to other techniques. However, ALPPS is associated with worse major complications, more deaths, and early tumor recurrence.Hepatobiliary surgeons should carefully consider whether to perform ALPPS. Some modified forms of ALPPS have reduced the mortality and morbidity of the procedure, but they cannot be recommended over the original procedure currently. Portal vein embolization (PVE) is still the procedure of choice for patients with a tumor-free FLR, and ALPPS could be used as a salvage procedure when PVE fails. More persuasive evidence needs to be assembled to determine whether ALPPS or two-stage hepatectomy (TSH) is better for patients with a tumor involving the FLR. Evidence with regard to long-term oncological outcomes is still limited. More meticulous comparative studies and studies of the 5-year survival rate of ALPPS could ultimately

Late-Cenozoic relief evolution under evolving climate: A review

OpenAIRE

Champagnac Jean Daniel; Valla Pierre G.; Herman Frédéric

2014-01-01

The present review paper is an attempt to summarize quantitative evidence of Late Cenozoic changes in topographic relief. Different meanings of the word "relief" as it is commonly used and detail the metrics used to quantify it. We then specify methodological tools used to quantify relief change (primarily low temperature thermochronometry and terrestrial cosmogenic nuclides) and analyze published evidence for different regions.Our review first shows that relief changes and rates of changes a...

Short stature caused by isolated SHOX gene haploinsufficiency: update on the diagnosis and treatment.

Science.gov (United States)

Jorge, Alexander A L; Funari, Mariana Fa; Nishi, Mirian Y; Mendonca, Berenice B

2010-12-01

Heterozygous SHOX defects are observed in about 50 to 90% of patients with Leri-Weill dyschondrosteosis (LWD), a common dominant inherited skeletal dysplasia; and in 2 to 15% of children with idiopathic short stature (ISS), indicating that SHOX defects are the most important monogenetic cause of short stature. In addition, children selected by disproportionate idiopathic short stature had a higher frequency of SHOX mutations (22%). A careful clinical evaluation of family members with short stature is recommended since it usually revealed LWD patients in families first classified as having ISS or familial short stature. SHOX-molecular analysis is indicated in families with LWD and ISS children with disproportionate short stature. Treatment with recombinant human growth hormone is considered an accepted approach to treat short stature associated with isolated SHOX defect. Here we review clinical, molecular and therapeutic aspects of SHOX haploinsufficiency.

Cell-to-cell communication in plants, animals, and fungi: a comparative review.

Science.gov (United States)

Bloemendal, Sandra; Kück, Ulrich

2013-01-01

Cell-to-cell communication is a prerequisite for differentiation and development in multicellular organisms. This communication has to be tightly regulated to ensure that cellular components such as organelles, macromolecules, hormones, or viruses leave the cell in a precisely organized way. During evolution, plants, animals, and fungi have developed similar ways of responding to this biological challenge. For example, in higher plants, plasmodesmata connect adjacent cells and allow communication to regulate differentiation and development. In animals, two main general structures that enable short- and long-range intercellular communication are known, namely gap junctions and tunneling nanotubes, respectively. Finally, filamentous fungi have also developed specialized structures called septal pores that allow intercellular communication via cytoplasmic flow. This review summarizes the underlying mechanisms for intercellular communication in these three eukaryotic groups and discusses its consequences for the regulation of differentiation and developmental processes.

Short-term mechanisms influencing volumetric brain dynamics

Directory of Open Access Journals (Sweden)

Nikki Dieleman

2017-01-01

Full Text Available With the use of magnetic resonance imaging (MRI and brain analysis tools, it has become possible to measure brain volume changes up to around 0.5%. Besides long-term brain changes caused by atrophy in aging or neurodegenerative disease, short-term mechanisms that influence brain volume may exist. When we focus on short-term changes of the brain, changes may be either physiological or pathological. As such determining the cause of volumetric dynamics of the brain is essential. Additionally for an accurate interpretation of longitudinal brain volume measures by means of neurodegeneration, knowledge about the short-term changes is needed. Therefore, in this review, we discuss the possible mechanisms influencing brain volumes on a short-term basis and set-out a framework of MRI techniques to be used for volumetric changes as well as the used analysis tools. 3D T1-weighted images are the images of choice when it comes to MRI of brain volume. These images are excellent to determine brain volume and can be used together with an analysis tool to determine the degree of volume change. Mechanisms that decrease global brain volume are: fluid restriction, evening MRI measurements, corticosteroids, antipsychotics and short-term effects of pathological processes like Alzheimer's disease, hypertension and Diabetes mellitus type II. Mechanisms increasing the brain volume include fluid intake, morning MRI measurements, surgical revascularization and probably medications like anti-inflammatory drugs and anti-hypertensive medication. Exercise was found to have no effect on brain volume on a short-term basis, which may imply that dehydration caused by exercise differs from dehydration by fluid restriction. In the upcoming years, attention should be directed towards studies investigating physiological short-term changes within the light of long-term pathological changes. Ultimately this may lead to a better understanding of the physiological short-term effects of

Modification of feeding circuits in the evolution of social behavior.

Science.gov (United States)

Fischer, Eva K; O'Connell, Lauren A

2017-01-01

Adaptive trade-offs between foraging and social behavior intuitively explain many aspects of individual decision-making. Given the intimate connection between social behavior and feeding/foraging at the behavioral level, we propose that social behaviors are linked to foraging on a mechanistic level, and that modifications of feeding circuits are crucial in the evolution of complex social behaviors. In this Review, we first highlight the overlap between mechanisms underlying foraging and parental care and then expand this argument to consider the manipulation of feeding-related pathways in the evolution of other complex social behaviors. We include examples from diverse taxa to highlight that the independent evolution of complex social behaviors is a variation on the theme of feeding circuit modification. © 2017. Published by The Company of Biologists Ltd.

Geology of Uruguay review

International Nuclear Information System (INIS)

Gomez Rifas, C.

2011-01-01

This work is about the Uruguay geology review.This country has been a devoted to breeding cattle and agriculture.The evolution of geological knowledge begun with Dr. Karl Walther who published 53 papers between 1909 and 1948.

Radiology, histology and short-term outcome of asymptomatic congenital thoracic malformations

DEFF Research Database (Denmark)

Kongstad, Thomas; Buchvald, Frederik; Brenøe, Jørn

2012-01-01

The aim of this study was to evaluate the safety and short-term outcome of our management of asymptomatic children with antenatally diagnosed congenital thoracic malformations (CTM), compared with recommendations from a recent review and meta-analysis....

Protein sequence comparison and protein evolution

Energy Technology Data Exchange (ETDEWEB)

Pearson, W.R. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Biochemistry

1995-12-31

This tutorial was one of eight tutorials selected to be presented at the Third International Conference on Intelligent Systems for Molecular Biology which was held in the United Kingdom from July 16 to 19, 1995. This tutorial examines how the information conserved during the evolution of a protein molecule can be used to infer reliably homology, and thus a shared proteinfold and possibly a shared active site or function. The authors start by reviewing a geological/evolutionary time scale. Next they look at the evolution of several protein families. During the tutorial, these families will be used to demonstrate that homologous protein ancestry can be inferred with confidence. They also examine different modes of protein evolution and consider some hypotheses that have been presented to explain the very earliest events in protein evolution. The next part of the tutorial will examine the technical aspects of protein sequence comparison. Both optimal and heuristic algorithms and their associated parameters that are used to characterize protein sequence similarities are discussed. Perhaps more importantly, they survey the statistics of local similarity scores, and how these statistics can both be used to improve the selectivity of a search and to evaluate the significance of a match. They them examine distantly related members of three protein families, the serine proteases, the glutathione transferases, and the G-protein-coupled receptors (GCRs). Finally, the discuss how sequence similarity can be used to examine internal repeated or mosaic structures in proteins.

Kinetic Monte Carlo simulation of phase-precipitation versus instability behavior in short period FeCr superlattices

Energy Technology Data Exchange (ETDEWEB)

Rodríguez-Martínez, F.J. [UCAM, Universidad Católica de Murcia, Campus de los Jerónimos, 30107 Guadalupe (Murcia) (Spain); Castejón-Mochón, J.F., E-mail: jfcastejon@ucam.edu [UCAM, Universidad Católica de Murcia, Campus de los Jerónimos, 30107 Guadalupe (Murcia) (Spain); Castrillo, P.; Berenguer-Vidal, R. [UCAM, Universidad Católica de Murcia, Campus de los Jerónimos, 30107 Guadalupe (Murcia) (Spain); Dopico, I.; Martin-Bragado, I. [IMDEA Materials Institute, Eric Kandel 2, 28906 Getafe (Madrid) (Spain)

2017-02-15

The structural evolution of FeCr superlattices has been studied using a quasi-atomistic Object Kinetic Monte Carlo model. Superlattices with different spatial periods have been simulated for anneal durations from few hours to several months at 500 °C. Relatively-long period superlattices stabilize into Fe-rich and Cr-rich layers with compositions close to those of bulk α and α′ phases. In contrast, superlattices with very short periods (4, 5, 6 nm) are observed to undergo instability and, for long annealing times, evolve into three-dimensionally decomposed regions, in qualitative agreement to recent experimental observations. The instability onset is delayed as the spatial period increases, and it occurs via interface roughness. This evolution can be explained as a minimization of the free-energy associated to the α/α′ interfaces. A comprehensive description of the evolution dynamics of FeCr-based structures is obtained with our model.

Short-Term Energy Outlook: Quarterly projections. Fourth quarter 1993

Energy Technology Data Exchange (ETDEWEB)

1993-11-05

The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the fourth quarter of 1993 through the fourth quarter of 1994. Values for the third quarter of 1993, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data are EIA data published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications.

The evolution of religious belief in humans: a brief review with a ...

Indian Academy of Sciences (India)

DHAIRYYA SINGH

2017-07-07

Jul 7, 2017 ... Keywords. religion; evolution; costly signalling; belief. Introduction. Religion is ... form) in evolutionary time scales, evolutionary scholars have tended to .... suggested that while altruism might hurt the genetic fitness of the actor at the .... According to their account, as we developed self-awareness and the.

Peer Review: Has It a Future?

Science.gov (United States)

Soh, Kay Cheng

2013-01-01

Although its history is short, peer review has fast become a fixture of journal publications acquiring the status of a ritual in the academia. Many relevant and important issues have been raised leading to doubts about the value of peer review. The advent of electronic publishing further threatens the future of peer review. For peer review to…

The early thermal evolution of Mars

Science.gov (United States)

Bhatia, G. K.; Sahijpal, S.

2016-01-01

Hf-W isotopic systematics of Martian meteorites have provided evidence for the early accretion and rapid core formation of Mars. We present the results of numerical simulations performed to study the early thermal evolution and planetary scale differentiation of Mars. The simulations are confined to the initial 50 Myr (Ma) of the formation of solar system. The accretion energy produced during the growth of Mars and the decay energy due to the short-lived radio-nuclides 26Al, 60Fe, and the long-lived nuclides, 40K, 235U, 238U, and 232Th are incorporated as the heat sources for the thermal evolution of Mars. During the core-mantle differentiation of Mars, the molten metallic blobs were numerically moved using Stoke's law toward the center with descent velocity that depends on the local acceleration due to gravity. Apart from the accretion and the radioactive heat energies, the gravitational energy produced during the differentiation of Mars and the associated heat transfer is also parametrically incorporated in the present work to make an assessment of its contribution to the early thermal evolution of Mars. We conclude that the accretion energy alone cannot produce widespread melting and differentiation of Mars even with an efficient consumption of the accretion energy. This makes 26Al the prime source for the heating and planetary scale differentiation of Mars. We demonstrate a rapid accretion and core-mantle differentiation of Mars within the initial ~1.5 Myr. This is consistent with the chronological records of Martian meteorites.

Noise in ecosystems: a short review.

Science.gov (United States)

Spagnolo, B; Valenti, D; Fiasconaro, A

2004-06-01

Noise, through its interaction with the nonlinearity of the living systems, can give rise to counter-intuitive phenomena such as stochastic resonance, noise-delayed extinction, temporal oscillations, and spatial patterns. In this paper we briefly review the noise-induced effects in three different ecosystems: (i) two competing species; (ii) three interacting species, one predator and two preys, and (iii) N-interacting species. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is random in cases (i) and (iii), and a periodical function, which accounts for the environmental temperature, in case (ii). We find noise-induced phenomena such as quasi-deterministic oscillations, stochastic resonance, noise-delayed extinction, and noise-induced pattern formation with nonmonotonic behaviors of patterns areas and of the density correlation as a function of the multiplicative noise intensity. The asymptotic behavior of the time average of the i(th) population when the ecosystem is composed of a great number of interacting species is obtained and the effect of the noise on the asymptotic probability distributions of the populations is discussed.

Disk Evolution and the Fate of Water

Science.gov (United States)

Hartmann, Lee; Ciesla, Fred; Gressel, Oliver; Alexander, Richard

2017-10-01

We review the general theoretical concepts and observational constraints on the distribution and evolution of water vapor and ice in protoplanetary disks, with a focus on the Solar System. Water is expected to freeze out at distances greater than 1-3 AU from solar-type central stars; more precise estimates are difficult to obtain due to uncertainties in the complex processes involved in disk evolution, including dust growth, settling, and radial drift, and the level of turbulence and viscous dissipation within disks. Interferometric observations are now providing constraints on the positions of CO snow lines, but extrapolation to the unresolved regions where water ice sublimates will require much better theoretical understanding of mass and angular momentum transport in disks as well as more refined comparison of observations with sophisticated disk models.

Predicting Key Events in the Popularity Evolution of Online Information.

Science.gov (United States)

Hu, Ying; Hu, Changjun; Fu, Shushen; Fang, Mingzhe; Xu, Wenwen

2017-01-01

The popularity of online information generally experiences a rising and falling evolution. This paper considers the "burst", "peak", and "fade" key events together as a representative summary of popularity evolution. We propose a novel prediction task-predicting when popularity undergoes these key events. It is of great importance to know when these three key events occur, because doing so helps recommendation systems, online marketing, and containment of rumors. However, it is very challenging to solve this new prediction task due to two issues. First, popularity evolution has high variation and can follow various patterns, so how can we identify "burst", "peak", and "fade" in different patterns of popularity evolution? Second, these events usually occur in a very short time, so how can we accurately yet promptly predict them? In this paper we address these two issues. To handle the first one, we use a simple moving average to smooth variation, and then a universal method is presented for different patterns to identify the key events in popularity evolution. To deal with the second one, we extract different types of features that may have an impact on the key events, and then a correlation analysis is conducted in the feature selection step to remove irrelevant and redundant features. The remaining features are used to train a machine learning model. The feature selection step improves prediction accuracy, and in order to emphasize prediction promptness, we design a new evaluation metric which considers both accuracy and promptness to evaluate our prediction task. Experimental and comparative results show the superiority of our prediction solution.

Predicting Key Events in the Popularity Evolution of Online Information.

Directory of Open Access Journals (Sweden)

Ying Hu

Full Text Available The popularity of online information generally experiences a rising and falling evolution. This paper considers the "burst", "peak", and "fade" key events together as a representative summary of popularity evolution. We propose a novel prediction task-predicting when popularity undergoes these key events. It is of great importance to know when these three key events occur, because doing so helps recommendation systems, online marketing, and containment of rumors. However, it is very challenging to solve this new prediction task due to two issues. First, popularity evolution has high variation and can follow various patterns, so how can we identify "burst", "peak", and "fade" in different patterns of popularity evolution? Second, these events usually occur in a very short time, so how can we accurately yet promptly predict them? In this paper we address these two issues. To handle the first one, we use a simple moving average to smooth variation, and then a universal method is presented for different patterns to identify the key events in popularity evolution. To deal with the second one, we extract different types of features that may have an impact on the key events, and then a correlation analysis is conducted in the feature selection step to remove irrelevant and redundant features. The remaining features are used to train a machine learning model. The feature selection step improves prediction accuracy, and in order to emphasize prediction promptness, we design a new evaluation metric which considers both accuracy and promptness to evaluate our prediction task. Experimental and comparative results show the superiority of our prediction solution.

The Evolution of U.S. Airline Competition

OpenAIRE

Severin Borenstein

1992-01-01

The next section reviews the evolution of the domestic airline industry since the late 1970s, when it was abruptly freed from most regulatory constraints on pricing, entry, and exit. (International air travel is considered here only as it relates to competition in the domestic industry.) The following sections will examine structure issues and strategic developments in airline competition and discuss public policy options in dealing with the airline industry.

Early evolution of the earth - Accretion, atmosphere formation, and thermal history

Science.gov (United States)

Abe, Yutaka; Matsui, Takafumi

1986-01-01

The thermal and atmospheric evolution of the earth growing planetesimal impacts are studied. The generation of an H2O protoatmosphere is examined, and the surface temperatures are estimated. The evolution of an impact-induced H2O atmosphere is analyzed. Consideration is given to the formation time of a 'magma ocean'and internal water budgets. The thermal history of an accreting earth is reviewed. The wet convection and greenhouse effects are discussed, and the role of Fe oxidation on the evolution of an impact-induced H2O atmopshere is described. The relationship between differentiation processes and core segregation, the H2O and FeO content of the mantle, and the origin of the hydrosphere is also examined.

Fundamental Dimensions of Environmental Risk : The Impact of Harsh versus Unpredictable Environments on the Evolution and Development of Life History Strategies.

Science.gov (United States)

Ellis, Bruce J; Figueredo, Aurelio José; Brumbach, Barbara H; Schlomer, Gabriel L

2009-06-01

The current paper synthesizes theory and data from the field of life history (LH) evolution to advance a new developmental theory of variation in human LH strategies. The theory posits that clusters of correlated LH traits (e.g., timing of puberty, age at sexual debut and first birth, parental investment strategies) lie on a slow-to-fast continuum; that harshness (externally caused levels of morbidity-mortality) and unpredictability (spatial-temporal variation in harshness) are the most fundamental environmental influences on the evolution and development of LH strategies; and that these influences depend on population densities and related levels of intraspecific competition and resource scarcity, on age schedules of mortality, on the sensitivity of morbidity-mortality to the organism's resource-allocation decisions, and on the extent to which environmental fluctuations affect individuals versus populations over short versus long timescales. These interrelated factors operate at evolutionary and developmental levels and should be distinguished because they exert distinctive effects on LH traits and are hierarchically operative in terms of primacy of influence. Although converging lines of evidence support core assumptions of the theory, many questions remain unanswered. This review demonstrates the value of applying a multilevel evolutionary-developmental approach to the analysis of a central feature of human phenotypic variation: LH strategy.

Internal and environmental secular evolution of disk galaxies

Science.gov (United States)

Kormendy, John

2015-03-01

This Special Session is devoted to the secular evolution of disk galaxies. Here `secular' means `slow' i.e., evolution on time scales that are generally much longer than the galaxy crossing or rotation time. Internal and environmentally driven evolution both are covered. I am indebted to Albert Bosma for reminding me at the 2011 Canary Islands Winter School on Secular Evolution that our subject first appeared in print in a comment made by Ivan King (1977) in his introductory talk at the Yale University meeting on The Evolution of Galaxies and Stellar Populations: `John Kormendy would like us to consider the possibility that a galaxy can interact with itself.. . . I'm not at all convinced, but John can show you some interesting pictures.' Two of the earliest papers that followed were Kormendy (1979a, b); the first discusses the interaction of galaxy components with each other, and the second studies these phenomena in the context of a morphological survey of barred galaxies. The earliest modeling paper that we still use regularly is Combes & Sanders (1981), which introduces the now well known idea that box-shaped bulges in edge-on galaxies are side-on, vertically thickened bars. It is gratifying to see how this subject has grown since that time. Hundreds of papers have been written, and the topic features prominently at many meetings (e.g., Block et al. 2004; Falcoń-Barroso & Knapen 2012, and this Special Session). My talk here introduces both internal and environmental secular evolution; a brief abstract follows. My Canary Islands Winter School review covers both subjects in more detail (Kormendy 2012). Kormendy & Kennicutt (2004) is a comprehensive review of internal secular evolution, and Kormendy & Bender (2012) covers environmental evolution. Both of these subject make significant progress at this meeting. Secular evolution happens because self-gravitating systems evolve toward the most tightly bound configuration that is reachable by the evolution processes

Calculating the spatio-temporal variability of bedrock exposure on seasonal hydrograph timescales as a prerequisite to modeling bedrock river evolution

Science.gov (United States)

Hurst, A. A.; Anderson, R. S.; Tucker, G. E.

2017-12-01

Erosion of bedrock river channels exerts significant control on landscape evolution because it communicates climatic and tectonic signals across a landscape by setting the lower erosional boundaries for hillslopes. Hillslope erosion delivers sediment to the channels, which then either store or transport the sediment. At times of high storage, access to the bedrock floor of the channel is limited, inhibiting bedrock erosion. This affects the timescale of channel response to imposed base-level lowering, which in turn affects hillslope erosion. Because occasional exposure of the bedrock bed is a minimum prerequisite for bedrock erosion, we seek to understand the evolution of sediment cover, or scour history, with sufficient resolution to answer when and where the bed is exposed. The scour history at a site is governed by grain size, bed and channel morphology, sediment concentration in the water, and seasonal flow conditions (hydrograph). The transient nature of bedrock exposure during high-flow events implies that short-term sediment cover dynamics are important for predicting long-term bedrock incision rates. Models of channel profile evolution, or of landscape evolution, generally ignore evolution of sediment cover on the hydrograph timescale. To develop insight into the necessary and sufficient conditions for bedrock exposure followed by reburial, we have developed a 1-D model of the evolution of alluvial cover thickness in a long channel profile in response to a seasonal hydrograph. This model tracks erosion, deposition, and the concentration of sediment in the water column separately, and generates histories of scour and fill over the course of the hydrograph. We compare the model's predictions with net-scour measurements in tributaries of the Grand Canyon and with scour-chain and accelerometer measurements in the Cedar River, Washington. By addressing alluvial scour on short timescales, we acknowledge the processes required to allow bedrock incision and

The evolution of massive stars

International Nuclear Information System (INIS)

Loore, C. de

1980-01-01

The evolution of stars with masses between 15 M 0 and 100 M 0 is considered. Stars in this mass range lose a considerable fraction of their matter during their evolution. The treatment of convection, semi-convection and the influence of mass loss by stellar winds at different evolutionary phases are analysed as well as the adopted opacities. Evolutionary sequences computed by various groups are examined and compared with observations, and the advanced evolution of a 15 M 0 and a 25 M 0 star from zero-age main sequence (ZAMS) through iron collapse is discussed. The effect of centrifugal forces on stellar wind mass loss and the influence of rotation on evolutionary models is examined. As a consequence of the outflow of matter deeper layers show up and when the mass loss rates are large enough layers with changed composition, due to interior nuclear reactions, appear on the surface. The evolution of massive close binaries as well during the phase of mass loss by stellar wind as during the mass exchange and mass loss phase due to Roche lobe overflow is treated in detail, and the value of the parameters governing mass and angular momentum losses are discussed. The problem of the Wolf-Rayet stars, their origin and the possibilities of their production either as single stars or as massive binaries is examined. Finally, the origin of X-ray binaries is discussed and the scenario for the formation of these objects (starting from massive ZAMS close binaries, through Wolf-Rayet binaries leading to OB-stars with a compact companion after a supernova explosion) is reviewed and completed, including stellar wind mass loss. (orig.)

Evaluation in the Private Sector: Evolution and Professionalization of Quality Management

NARCIS (Netherlands)

Godfroij, A.J.A.

1995-01-01

This article reviews different approaches to quality management in the private sector from an evolutionary perspective. Two dimensions of this evolution are crucial: the scope of evaluation (“product” versus “system”) and the objective versus intersubjective orientation. Experiences within the

Polish scientists in fish immunology: a short history : review

NARCIS (Netherlands)

Muiswinkel, van W.B.; Pilarczyk, A.

2015-01-01

This review describes the role played by Polish scientists in the field of fish immunology and vaccination starting around 1900. In the early days, most publications were dealing with a description of relevant cells and organs in fish. Functional studies (phagocytosis, antibody response) came later

General review on climate change problems: causes, potential effects

International Nuclear Information System (INIS)

Martellet, J.

1991-01-01

Greenhouse gases and greenhouse effect principles are reviewed and climate changes due to the human activities are discussed: identification of gases, human or natural causes, composition evolution in the atmosphere and relative roles of greenhouse gases. The various tools and calculations methods for evaluating the climate change due to greenhouse effect are presented. Several problems are stated: evolution of the climate structure in 2030, variations of the climatic extremes and the extreme phenomena, augmentation or diminution of the storms on a warmed planet, long term evolution of the climate. Some consequences of a climate change are reviewed: sea level raising, climate change effects on ecosystems. Precision and validity of these predictions are discussed; recommendations for diminishing the uncertainties are proposed

Comparative Genomics of 28 Salmonella enterica Isolates: Evidence for CRISPR-Mediated Adaptive Sublineage Evolution ▿†

Science.gov (United States)

Fricke, W. Florian; Mammel, Mark K.; McDermott, Patrick F.; Tartera, Carmen; White, David G.; LeClerc, J. Eugene; Ravel, Jacques; Cebula, Thomas A.

2011-01-01

Despite extensive surveillance, food-borne Salmonella enterica infections continue to be a significant burden on public health systems worldwide. As the S. enterica species comprises sublineages that differ greatly in antigenic representation, virulence, and antimicrobial resistance phenotypes, a better understanding of the species' evolution is critical for the prediction and prevention of future outbreaks. The roles that virulence and resistance phenotype acquisition, exchange, and loss play in the evolution of S. enterica sublineages, which to a certain extent are represented by serotypes, remains mostly uncharacterized. Here, we compare 17 newly sequenced and phenotypically characterized nontyphoidal S. enterica strains to 11 previously sequenced S. enterica genomes to carry out the most comprehensive comparative analysis of this species so far. These phenotypic and genotypic data comparisons in the phylogenetic species context suggest that the evolution of known S. enterica sublineages is mediated mostly by two mechanisms, (i) the loss of coding sequences with known metabolic functions, which leads to functional reduction, and (ii) the acquisition of horizontally transferred phage and plasmid DNA, which provides virulence and resistance functions and leads to increasing specialization. Matches between S. enterica clustered regularly interspaced short palindromic repeats (CRISPR), part of a defense mechanism against invading plasmid and phage DNA, and plasmid and prophage regions suggest that CRISPR-mediated immunity could control short-term phenotype changes and mediate long-term sublineage evolution. CRISPR analysis could therefore be critical in assessing the evolutionary potential of S. enterica sublineages and aid in the prediction and prevention of future S. enterica outbreaks. PMID:21602358

Respiratory consequences of prematurity: evolution of a diagnosis and development of a comprehensive approach.

Science.gov (United States)

Maitre, Nathalie L; Ballard, Roberta A; Ellenberg, Jonas H; Davis, Stephanie D; Greenberg, James M; Hamvas, Aaron; Pryhuber, Gloria S

2015-05-01

Bronchopulmonary dysplasia (BPD) is the most common respiratory consequence of premature birth and contributes to significant short- and long-term morbidity, mortality and resource utilization. Initially defined as a radiographic, clinical and histopathological entity, the chronic lung disease known as BPD has evolved as obstetrical and neonatal care have improved the survival of lower gestational age infants. Now, definitions based on the need for supplementary oxygen at 28 days and/or 36 weeks provide a useful reference point in the neonatal intensive-care unit (NICU), but are no longer based on histopathological findings, and are neither designed to predict longer term respiratory consequences nor to study the evolution of a multifactorial disease. The aims of this review are to critically examine the evolution of the diagnosis of BPD and the challenges inherent to current classifications. We found that the increasing use of respiratory support strategies that administer ambient air without supplementary oxygen confounds oxygen-based definitions of BPD. Furthermore, lack of reproducible, genetic, biochemical and physiological biomarkers limits the ability to identify an impending BPD for early intervention, quantify disease severity for standardized classification and approaches and reliably predict the long-term outcomes. More comprehensive, multidisciplinary approaches to overcome these challenges involve longitudinal observation of extremely preterm infants, not only those with BPD, using genetic, environmental, physiological and clinical data as well as large databases of patient samples. The Prematurity and Respiratory Outcomes Program (PROP) will provide such a framework to address these challenges through high-resolution characterization of both NICU and post-NICU discharge outcomes.

Structure and evolution of magnetic fields associated with solar eruptions

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