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Sample records for rat problems require

  1. Requirements Elicitation Problems: A Literature Analysis

    Directory of Open Access Journals (Sweden)

    Bill Davey

    2015-06-01

    Full Text Available Requirements elicitation is the process through which analysts determine the software requirements of stakeholders. Requirements elicitation is seldom well done, and an inaccurate or incomplete understanding of user requirements has led to the downfall of many software projects. This paper proposes a classification of problem types that occur in requirements elicitation. The classification has been derived from a literature analysis. Papers reporting on techniques for improving requirements elicitation practice were examined for the problem the technique was designed to address. In each classification the most recent or prominent techniques for ameliorating the problems are presented. The classification allows the requirements engineer to be sensitive to problems as they arise and the educator to structure delivery of requirements elicitation training.

  2. Problem-Oriented Requirements in Practice

    DEFF Research Database (Denmark)

    Lauesen, Søren

    2018-01-01

    [Context and motivation] Traditional requirements describe what the system shall do. This gives suppliers little freedom to use what they have already. In contrast, problem-oriented requirements describe the customer’s demands: what he wants to use the system for and which problems he wants...... to remove. The supplier specifies how his system will deal with these issues. The author developed the problem-oriented approach in 2007 on request from the Danish Government, and named it SL-07. [Question/problem] SL-07 has been used in many projects – usually with success. However, we had no detailed re......¬ports of the effects. [Princi¬pal ideas/results] This paper is a case study of SL-07 in acquisition of a complex case-management system. The author wrote the requirements and managed the supplier selection. Next, he was asked to run the entire acquisition project, although he was a novice project manager. Some...

  3. Vitamin K requirement in Danish anticoagulant-resistant Norway rats (Rattus norvegicus)

    DEFF Research Database (Denmark)

    Markussen, Mette D.; Heiberg, Ann-Charlotte; Nielsen, Robert

    2003-01-01

    Norway rats, Rattus norvegicus, Denmark, anticoagulant rodenticide resistance, vitamin K requirement......Norway rats, Rattus norvegicus, Denmark, anticoagulant rodenticide resistance, vitamin K requirement...

  4. Requirement of alveolar bone formation for eruption of rat molars

    Science.gov (United States)

    Wise, Gary E.; He, Hongzhi; Gutierrez, Dina L.; Ring, Sherry; Yao, Shaomian

    2011-01-01

    Tooth eruption is a localized event that requires a dental follicle (DF) to regulate the resorption of alveolar bone to form an eruption pathway. During the intra-osseous phase of eruption, the tooth moves through this pathway. The mechanism or motive force that propels the tooth through this pathway is controversial but many studies have shown that alveolar bone growth at the base of the crypt occurs during eruption. To determine if this bone growth (osteogenesis) was causal, experiments were designed in which the expression of an osteogenic gene in the DF, bone morphogenetic protein-6 (BMP6), was inhibited by injection of the 1st mandibular molar of the rat with an siRNA targeted against BMP6. The injection was followed by electroporation to promote uptake of the siRNA. In 45 first molars injected, eruption either was delayed or completely inhibited (7 molars). In the impacted molars, an eruption pathway formed but bone growth at the base of the crypt was greatly reduced as compared to the erupted first molar controls. These studies show that alveolar bone growth at the base of the crypt is required for tooth eruption and that BMP6 may be an essential gene for promoting this growth. PMID:21896048

  5. Requirements Engineering as Creative Problem Solving: A Research Agenda for Idea Finding

    OpenAIRE

    Maiden, N.; Jones, S.; Karlsen, I. K.; Neill, R.; Zachos, K.; Milne, A.

    2010-01-01

    This vision paper frames requirements engineering as a creative problem solving process. Its purpose is to enable requirements researchers and practitioners to recruit relevant theories, models, techniques and tools from creative problem solving to understand and support requirements processes more effectively. It uses 4 drivers to motivate the case for requirements engineering as a creative problem solving process. It then maps established requirements activities onto one of the longest-esta...

  6. A Generalized Cauchy Distribution Framework for Problems Requiring Robust Behavior

    Directory of Open Access Journals (Sweden)

    Carrillo RafaelE

    2010-01-01

    Full Text Available Statistical modeling is at the heart of many engineering problems. The importance of statistical modeling emanates not only from the desire to accurately characterize stochastic events, but also from the fact that distributions are the central models utilized to derive sample processing theories and methods. The generalized Cauchy distribution (GCD family has a closed-form pdf expression across the whole family as well as algebraic tails, which makes it suitable for modeling many real-life impulsive processes. This paper develops a GCD theory-based approach that allows challenging problems to be formulated in a robust fashion. Notably, the proposed framework subsumes generalized Gaussian distribution (GGD family-based developments, thereby guaranteeing performance improvements over traditional GCD-based problem formulation techniques. This robust framework can be adapted to a variety of applications in signal processing. As examples, we formulate four practical applications under this framework: (1 filtering for power line communications, (2 estimation in sensor networks with noisy channels, (3 reconstruction methods for compressed sensing, and (4 fuzzy clustering.

  7. Core Problem: Does the CV Parent Body Magnetization require differentiation?

    Science.gov (United States)

    O'Brien, T.; Tarduno, J. A.; Smirnov, A. V.

    2016-12-01

    Evidence for the presence of past dynamos from magnetic studies of meteorites can provide key information on the nature and evolution of parent bodies. However, the suggestion of a past core dynamo for the CV parent body based on the study of the Allende meteorite has led to a paradox: a core dynamo requires differentiation, evidence for which is missing in the meteorite record. The key parameter used to distinguish core dynamo versus external field mechanisms is absolute field paleointensity, with high values (>>1 μT) favoring the former. Here we explore the fundamental requirements for absolute field intensity measurement in the Allende meteorite: single domain grains that are non-interacting. Magnetic hysteresis and directional data define strong magnetic interactions, negating a standard interpretation of paleointensity measurements in terms of absolute paleofield values. The Allende low field magnetic susceptibility is dominated by magnetite and FeNi grains, whereas the magnetic remanence is carried by an iron sulfide whose remanence-carrying capacity increases with laboratory cycling at constant field values, indicating reordering. The iron sulfide and FeNi grains are in close proximity, providing mineralogical context for interactions. We interpret the magnetization of Allende to record the intense early solar wind with metal-sulfide interactions amplifying the field, giving the false impression of a higher field value in some prior studies. An undifferentiated CV parent body is thus compatible with Allende's magnetization. Early solar wind magnetization should be the null hypothesis for evaluating the source of magnetization for chondrites and other meteorites.

  8. How to make university students solve physics problems requiring mathematical skills: The "Adventurous Problem Solving" approach

    NARCIS (Netherlands)

    de Mul, F.F.M.; Martin Batlle, C.; Martin i Batlle, Cristina; de Bruijn, Imme; Rinzema, K.; Rinzema, Kees

    2003-01-01

    Teaching physics to first-year university students (in the USA: junior/senior level) is often hampered by their lack of skills in the underlying mathematics, and that in turn may block their understanding of the physics and their ability to solve problems. Examples are vector algebra, differential

  9. Nicotine intake and problem solving strategies are modified during a cognitively demanding water maze task in rats.

    Science.gov (United States)

    Nesil, Tanseli; Kanit, Lutfiye; Pogun, Sakire

    2015-11-01

    Nicotine is the major addictive component in tobacco, and despite well-established adverse health effects of tobacco addiction, some smokers have difficulty quitting. The acute cognitive enhancement and/or the amelioration of the cognitive disruption during withdrawal that some smokers experience after smoking are among important factors that hinder quit attempts. The animal model presented in the current study is comparable to the human smoking condition although nicotine intake routes are different. Rats were exposed to a free choice of oral nicotine starting at adolescence, and given a water maze (WM) task as adults. This design allowed us to see if rats alter their nicotine intake during the WM task and if nicotine preference and intake modify abilities and strategies rats use for problem solving. Male and female rats were exposed to a free choice of oral nicotine/water for 24weeks, starting at five weeks of age. After this period, they were selected based on their nicotine intake and, together with control animals that received only water, were subjected to a place-learning task in the WM. Free-choice nicotine exposure continued during WM testing. Following acquisition, the probe trial presented the rats with a choice between using two different strategies for problem solving. Nicotine supported acquisition and rats increased their nicotine intake during WM testing; this effect was more pronounced in male rats with minimum nicotine preference and intake. Furthermore, nicotine modified the "female type" strategy in solving the place-learning task and nicotine treated female rats, unlike control females, behaved like males. The increase in nicotine intake during mental engagement, and the sexually dimorphic effect of nicotine on problem solving strategies that we have observed in rats, may suggest that implementing sex-specific smoking cessation approaches, especially under stressful and cognitively demanding conditions, may be useful in helping smokers quit

  10. Problems about the analysis of technical requirements compliance in NPPPCI systems

    International Nuclear Information System (INIS)

    Perello, M.

    1978-01-01

    The display of the problems that the analysis of the technical requirements compliance bring along is presented. In the project of nuclear power plants, above all, the influence of national and international standards in the analysis of the adjustment of requirements established by the governments of nuclear safety of the different countries. In the oral presentation greater emphasis is made on the difficulties that the PSAR evaluation brings when the lack of technical standards in the owner country makes necessary the use of other countries rules. (author)

  11. Parametric linear programming for a materials requirement planning problem solution with uncertainty

    OpenAIRE

    Martin Darío Arango Serna; Conrado Augusto Serna; Giovanni Pérez Ortega

    2010-01-01

    Using fuzzy set theory as a methodology for modelling and analysing decision systems is particularly interesting for researchers in industrial engineering because it allows qualitative and quantitative analysis of problems involving uncertainty and imprecision. Thus, in an effort to gain a better understanding of the use of fuzzy logic in industrial engineering, more specifically in the field of production planning, this article was aimed at providing a materials requirement planning (MRP) pr...

  12. Pyrroloquinoline quinone ameliorates l-thyroxine-induced hyperthyroidism and associated problems in rats.

    Science.gov (United States)

    Kumar, Narendra; Kar, Anand; Panda, Sunanda

    2014-08-01

    Pyrroloquinoline quinone (PQQ) is believed to be a strong antioxidant. In this study, we have evaluated its hitherto unknown role in l-thyroxin (L-T4 )-induced hyperthyroidism considering laboratory rat as a model. Alterations in the serum concentration of thyroxin (T4 ) and triiodothyronine (T3 ); lipid peroxidation (LPO) of liver, kidney, heart, muscles and brain; in the endogenous antioxidants such as superoxide dismutase, catalase and glutathione and in serum total cholesterol, high-density lipoprotien, triglycerides, serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and urea were evaluated. Administration of l-T4 (500-µg kg(-1) body weight) enhanced not only the serum T3 and T4 levels but also the tissue LPO, serum SGOT, SGPT and urea with a parallel decrease in the levels of antioxidants and serum lipids. However, on simultaneous administration of PQQ (5 mg kg(-1) for 6 days), all these adverse effects were ameliorated, indicating the potential of PQQ in the amelioration of hyperthyroidism and associated problems. Possibly, the curative effects were mediated through inhibition of oxidative stress. We suggest that PQQ may be considered for therapeutic use for hyperthyroidism after dose standardization. Copyright © 2014 John Wiley & Sons, Ltd.

  13. An Analysis of the Network Selection Problem for Heterogeneous Environments with User-Operator Joint Satisfaction and Multi-RAT Transmission

    Directory of Open Access Journals (Sweden)

    J. J. Escudero-Garzás

    2017-01-01

    Full Text Available The trend in wireless networks is that several wireless radio access technologies (RATs coexist in the same area, forming heterogeneous networks in which the users may connect to any of the available RATs. The problem of associating a user to the most suitable RAT, known as network selection problem (NSP, is of capital importance for the satisfaction of the users in these emerging environments. However, also the satisfaction of the operator is important in this scenario. In this work, we propose that a connection may be served by more than one RAT by using multi-RAT terminals. We formulate the NSP with multiple RAT association based on utility functions that take into consideration both user’s satisfaction and provider’s satisfaction. As users are characterized according to their expected quality of service, our results exhaustively analyze the influence of the user’s profile, along with the network topology and the type of applications served.

  14. Requirement of cholesterol for secretion of the very low density lipoprotein (VLDL) by the rat liver

    International Nuclear Information System (INIS)

    Khan, B.; Wilcox, H.G.; Elam, M.B.; Heimberg, M.

    1987-01-01

    Fatty acids stimulate hepatic secretion of VLDL triglyceride (TG) and cholesterol (C), increase C synthesis, and enhance activity of HMG-CoA reductase. Livers from normal fed male rats were perfused for 4 hr in a medium containing 20μCi [2- 14 C] acetate, 6g/dl serum albumin, 300 mg/dl glucose in Krebs-Henseleit HCO 3 buffer (pH 7.4), 0-100 μg/ml mevinolin, and oleate. TG secretion was decreased 0%, 23%, and 32% from control with 1, 10, and 100 μg/ml mevinolin, respectively; there was no significant effect on C or C ester (CE) secretion. Specific activity (dpm/μmol) of C synthesized from acetate in the liver decreased 67%, 98%, and 99% from control; incorporation into CE decreased 64%, 81%, and 84%, respectively. TG and phospholipid (PL) activities did not change. Synthesis of TG and PL from [1- 14 C] oleate by isolated hepatocytes from normal fed rats was not affected by addition of 0-100 μg/ml mevinolin. The mass of C and TG in the liver did not change. Preliminary experiments with perfused liver suggest that output of VLDL TG, C, CE, and PL was diminished; the ratio of C/TG and PL/TG in the VLDL was constant, suggesting secretion of fewer VLDL particles with the same composition. These data suggest that mevinolin acutely reduces biosynthesis of C and secretion of the VLDL, presumably because of a requirement of C for synthesis and secretion of the VLDL

  15. Folliculostellate Cells Are Required for Laminin Release from Gonadotrophs in Rat Anterior Pituitary

    International Nuclear Information System (INIS)

    Tsukada, Takehiro; Fujiwara, Ken; Horiguchi, Kotaro; Azuma, Morio; Ramadhani, Dini; Tofrizal, Alimuddin; Batchuluun, Khongorzul; Maliza, Rita; Syaidah, Rahimi; Kikuchi, Motoshi; Yashiro, Takashi

    2014-01-01

    The anterior pituitary gland is organized tissue comprising hormone-producing cells and folliculostellate (FS) cells. FS cells interconnect to form a meshwork, and their cytoplasmic processes are anchored by a basement membrane containing laminin. Recently, we developed a three-dimensional (3D) cell culture that reproduces this FS cell architecture. In this study of the novel function of FS cells, we used transgenic rats that express green fluorescent protein in FS cells for the 3D culture. Anterior pituitary cells were cultured with different proportions of FS cells (0%, 5%, 10%, and 20%). Anterior pituitary cells containing 5–20% FS cells formed round/oval cell aggregates, whereas amorphous cell aggregates were formed in the absence of FS cells. Interestingly, immunohistochemistry showed laminin-immunopositive cells instead of extracellular laminin deposition in FS cell-deficient cell aggregates. Double-immunostaining revealed that these laminin-immunopositive cells were gonadotrophs. Laminin mRNA expression did not differ in relation to the presence or absence of FS cells. When anterior pituitary cells with no FS cells were cultured with FS cell-conditioned medium, the proportion of laminin-immunopositive cells was lower than in control. These results suggest that a humoral factor from FS cells is required for laminin release from gonadotrophs

  16. Sodium Is Not Required for Chloride Efflux via Chloride/Bicarbonate Exchanger from Rat Thymic Lymphocytes

    Directory of Open Access Journals (Sweden)

    Donatas Stakišaitis

    2014-01-01

    Full Text Available Sodium-dependent Cl−/HCO3- exchanger acts as a chloride (Cl− efflux in lymphocytes. Its functional characterization had been described when Cl− efflux was measured upon substituting extracellular sodium (Na+ by N-methyl-D-glucamine (NMDG. For Na+ and Cl− substitution, we have used D-mannitol or NMDG. Thymocytes of male Wistar rats aged 7–9 weeks were used and intracellular Cl− was measured by spectrofluorimetry using MQAE dye in bicarbonate buffers. Chloride efflux was measured in a Cl−-free buffer (Cl− substituted with isethionate acid and in Na+ and Cl−-free buffer with D-mannitol or with NMDG. The data have shown that Cl− efflux is mediated in the absence of Na+ in a solution containing D-mannitol and is inhibited by H2DIDS. Mathematical modelling has shown that Cl− efflux mathematical model parameters (relative membrane permeability, relative rate of exchanger transition, and exchanger efficacy were the same in control and in the medium in which Na+ had been substituted by D-mannitol. The net Cl− efflux was completely blocked in the NMDG buffer. The same blockage of Cl− efflux was caused by H2DIDS. The study results allow concluding that Na+ is not required for Cl− efflux via Cl−/HCO3- exchanger. NMDG in buffers cannot be used for substituting Na+ because NMDG inhibits the exchanger.

  17. 49 CFR 40.208 - What problem requires corrective action but does not result in the cancellation of a test?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What problem requires corrective action but does not result in the cancellation of a test? 40.208 Section 40.208 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Problems...

  18. Rapid postmortem gut autolysis in infant rats: a potential problem for investigators.

    Science.gov (United States)

    Scheifele, D; Bjornson, G; Dimmick, J

    1987-01-01

    Experiments were designed to determine the rate and nature of postmortem autolysis in the gut of neonatal rats, as necessary baseline information for developing a model of human neonatal necrotizing enterocolitis. We studied 60 animals, including 33 Wistar rats, 18 Sprague-Dawley rats and nine CD-1 mice. The variables examined included age of the animals (2 or 14 days) and length of delay and holding temperature (20 degrees C or 37 degrees C) after sacrifice. At necropsy, bowel was rapidly removed and fixed for histopathological examination. In all instances, bowel removed immediately after sacrifice was normal whereas after delays as short as 30 minutes it was abnormal (P less than 0.001), becoming markedly so after 60 minutes. The prominent features were detachment and lysis of mucosal epithelial cells. The rate of autolysis was not altered in 14 day old animals or in carcasses held at 20 degrees C or 37 degrees C. Investigators of bowel injury syndromes in young rats should be aware that histopathological studies will be valid only if specimens held at room temperature are fixed within 15 minutes of death. Images Fig. 1. PMID:3651898

  19. How Students Circumvent Problem-Solving Strategies that Require Greater Cognitive Complexity.

    Science.gov (United States)

    Niaz, Mansoor

    1996-01-01

    Analyzes the great diversity in problem-solving strategies used by students in solving a chemistry problem and discusses the relationship between these variables and different cognitive variables. Concludes that students try to circumvent certain problem-solving strategies by adapting flexible and stylistic innovations that render the cognitive…

  20. Epithelial growth by rat vibrissae follicles in vitro requires mesenchymal contact via native extracellular matrix

    International Nuclear Information System (INIS)

    Link, R.E.; Paus, R.; Stenn, K.S.; Kuklinska, E.; Moellmann, G.

    1990-01-01

    An in vitro assay utilizing the rat vibrissa anagen follicle as a model for studying the epithelial-mesenchymal interactions (EMI) in hair growth is described. Through selective disruption of the epithelial-mesenchymal interface, we investigate whether the specialized extracellular matrix (ECM) of the dermal papilla and basement membrane zone (BMZ) serves a crucial function in hair follicle EMI. Epithelial bulbs incubated intact within their follicular sheaths incorporate thymidine primarily into cells of the hair matrix and outer root sheath, as shown by autoradiography. However, after removal of its mesenchymal associations (dermal papilla and extrabulbar connective tissue), the epithelial bulb showed no incorporation. Neither externally added collagen (type I or IV) nor the basement membrane components in Matrigel could substitute for the growth supporting influence of native surrounding stroma. Mechanical separation of the bulb from the dermal papilla in the basement membrane zone inhibited thymidine incorporation by the epithelium even though mesenchyme was still in close proximity. Enzymatic digestion of the dermal papilla ECM and the basal lamina by Dispase, a fibronectinase and type IV collagenase, also inhibited bulb growth without evidence of cytotoxicity. These experiments suggest that direct epithelial to mesenchymal contact is required for the support of follicular epithelial growth in vitro and that specific ECM components, possibly fibronectin and/or type IV collagen, rather than diffusable factors alone, play a crucial role in the mechanism of hair follicle EMI. The in vitro system described here provides an alternative to developmental EMI models and may serve as a valuable tool for studying EMI in the adult mammalian organism

  1. Endogenous BDNF is required for long-term memory formation in the rat parietal cortex.

    Science.gov (United States)

    Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

    2005-01-01

    Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

  2. Cognitive and motivational requirements for the emergence of cooperation in a rat social game.

    Science.gov (United States)

    Viana, Duarte S; Gordo, Isabel; Sucena, Elio; Moita, Marta A P

    2010-01-13

    Game theory and the Prisoner's Dilemma (PD) game in particular, which captures the paradox of cooperative interactions that lead to benefits but entail costs to the interacting individuals, have constituted a powerful tool in the study of the mechanisms of reciprocity. However, in non-human animals most tests of reciprocity in PD games have resulted in sustained defection strategies. As a consequence, it has been suggested that under such stringent conditions as the PD game humans alone have evolved the necessary cognitive abilities to engage in reciprocity, namely, numerical discrimination, memory and control of temporal discounting. We use an iterated PD game to test rats (Rattus norvegicus) for the presence of such cognitive abilities by manipulating the strategy of the opponent, Tit-for-Tat and Pseudo-Random, or the relative size of the temptation to defect. We found that rats shape their behaviour according to the opponent's strategy and the relative outcome resulting from cooperative or defective moves. Finally, we show that the behaviour of rats is contingent upon their motivational state (hungry versus sated). Here we show that rats understand the payoff matrix of the PD game and the strategy of the opponent. Importantly, our findings reveal that rats possess the necessary cognitive capacities for reciprocity-based cooperation to emerge in the context of a prisoner's dilemma. Finally, the validation of the rat as a model to study reciprocity-based cooperation during the PD game opens new avenues of research in experimental neuroscience.

  3. A hybrid algorithm for stochastic single-source capacitated facility location problem with service level requirements

    Directory of Open Access Journals (Sweden)

    Hosseinali Salemi

    2016-04-01

    Full Text Available Facility location models are observed in many diverse areas such as communication networks, transportation, and distribution systems planning. They play significant role in supply chain and operations management and are one of the main well-known topics in strategic agenda of contemporary manufacturing and service companies accompanied by long-lasting effects. We define a new approach for solving stochastic single source capacitated facility location problem (SSSCFLP. Customers with stochastic demand are assigned to set of capacitated facilities that are selected to serve them. It is demonstrated that problem can be transformed to deterministic Single Source Capacitated Facility Location Problem (SSCFLP for Poisson demand distribution. A hybrid algorithm which combines Lagrangian heuristic with adjusted mixture of Ant colony and Genetic optimization is proposed to find lower and upper bounds for this problem. Computational results of various instances with distinct properties indicate that proposed solving approach is efficient.

  4. Characterizing the Fundamental Intellectual Steps Required in the Solution of Conceptual Problems

    Science.gov (United States)

    Stewart, John

    2010-02-01

    At some level, the performance of a science class must depend on what is taught, the information content of the materials and assignments of the course. The introductory calculus-based electricity and magnetism class at the University of Arkansas is examined using a catalog of the basic reasoning steps involved in the solution of problems assigned in the class. This catalog was developed by sampling popular physics textbooks for conceptual problems. The solution to each conceptual problem was decomposed into its fundamental reasoning steps. These fundamental steps are, then, used to quantify the distribution of conceptual content within the course. Using this characterization technique, an exceptionally detailed picture of the information flow and structure of the class can be produced. The intellectual structure of published conceptual inventories is compared with the information presented in the class and the dependence of conceptual performance on the details of coverage extracted. )

  5. THE PROBLEM OF ARCHITECTURE DESIGN IN A CONTEXT OF PARTIALLY KNOWN REQUIREMENTS OF COMPLEX WEB BASED APPLICATION "KSU FEEDBACK"

    Directory of Open Access Journals (Sweden)

    A. Spivakovsky

    2013-03-01

    Full Text Available The problem of flexible architecture design for critical parts of “KSU Feedback” application which do not have full requirements or clearly defined scope. Investigated recommended practices for solving such type of tasks and shown how they are applied in “KSU Feedback” architecture.

  6. War games: using MRP (material requirements planning) audits to pinpoint problems and keep the competitive edge.

    Science.gov (United States)

    Porter, S H; Yocus, T E

    1994-05-01

    In today's world, it is a challenge just to stay in business, let alone remain competitive in a specific industry. We will show you how to pinpoint MRP II problems and attack them through self-assessment audits. You will discover the secrets of breaking down barriers between Master Schedulers, Material Planners, Production Control Planners, and the Manufacturing Line. Self-assessment audits are one way to take care of your planning functions before outside auditors take care of them for you.

  7. Improving Deterministic Reserve Requirements for Security Constrained Unit Commitment and Scheduling Problems in Power Systems

    Science.gov (United States)

    Wang, Fengyu

    Traditional deterministic reserve requirements rely on ad-hoc, rule of thumb methods to determine adequate reserve in order to ensure a reliable unit commitment. Since congestion and uncertainties exist in the system, both the quantity and the location of reserves are essential to ensure system reliability and market efficiency. The modeling of operating reserves in the existing deterministic reserve requirements acquire the operating reserves on a zonal basis and do not fully capture the impact of congestion. The purpose of a reserve zone is to ensure that operating reserves are spread across the network. Operating reserves are shared inside each reserve zone, but intra-zonal congestion may block the deliverability of operating reserves within a zone. Thus, improving reserve policies such as reserve zones may improve the location and deliverability of reserve. As more non-dispatchable renewable resources are integrated into the grid, it will become increasingly difficult to predict the transfer capabilities and the network congestion. At the same time, renewable resources require operators to acquire more operating reserves. With existing deterministic reserve requirements unable to ensure optimal reserve locations, the importance of reserve location and reserve deliverability will increase. While stochastic programming can be used to determine reserve by explicitly modelling uncertainties, there are still scalability as well as pricing issues. Therefore, new methods to improve existing deterministic reserve requirements are desired. One key barrier of improving existing deterministic reserve requirements is its potential market impacts. A metric, quality of service, is proposed in this thesis to evaluate the price signal and market impacts of proposed hourly reserve zones. Three main goals of this thesis are: 1) to develop a theoretical and mathematical model to better locate reserve while maintaining the deterministic unit commitment and economic dispatch

  8. Reactivation in vitro of zinc-requiring apo-enzymes by rat liver zinc-thionein

    OpenAIRE

    Udom, Albert O.; Brady, Frank O.

    1980-01-01

    The ability of rat liver zinc-thionein to donate its metal to the apo-enzymes of the zinc enzymes horse liver alcohol dehydrogenase, yeast aldolase, thermolysin, Escherichia coli alkaline phosphatase and bovine erythrocyte carbonic anhydrase was investigated. Zinc-thionein was as good as, or better than, ZnSO4, Zn(CH3CO2)2 or Zn(NO3)2 in donating its zinc to these apo-enzymes. Apo-(alcohol dehydrogenase) could not be reactivated by zinc salts or by zinc-thionein. Incubation of the other apo-e...

  9. A scenario analysis of the future residential requirements for people with mental health problems in Eindhoven.

    Science.gov (United States)

    Bierbooms, Joyce J P A; Bongers, Inge M B; van Oers, Hans A M

    2011-01-06

    Despite large-scale investments in mental health care in the community since the 1990 s, a trend towards reinstitutionalization has been visible since 2002. Since many mental health care providers regard this as an undesirable trend, the question arises: In the coming 5 years, what types of residence should be organized for people with mental health problems? The purpose of this article is to provide mental health care providers, public housing corporations, and local government with guidelines for planning organizational strategy concerning types of residence for people with mental health problems. A scenario analysis was performed in four steps: 1) an exploration of the external environment; 2) the identification of key uncertainties; 3) the development of scenarios; 4) the translation of scenarios into guidelines for planning organizational strategy. To explore the external environment a document study was performed, and 15 semi-structured interviews were conducted. During a workshop, a panel of experts identified two key uncertainties in the external environment, and formulated four scenarios. The study resulted in four scenarios: 1) Integrated and independent living in the community with professional care; 2) Responsible healthcare supported by society; 3) Differentiated provision within the walls of the institution; 4) Residence in large-scale institutions but unmet need for care. From the range of aspects within the different scenarios, the panel was able to work out concrete guidelines for planning organizational strategy. In the context of residence for people with mental health problems, the focus should be on investment in community care and their re-integration into society. A joint effort is needed to achieve this goal. This study shows that scenario analysis leads to useful guidelines for planning organizational strategy in mental health care.

  10. PKC-epsilon activation is required for recognition memory in the rat.

    Science.gov (United States)

    Zisopoulou, Styliani; Asimaki, Olga; Leondaritis, George; Vasilaki, Anna; Sakellaridis, Nikos; Pitsikas, Nikolaos; Mangoura, Dimitra

    2013-09-15

    Activation of PKCɛ, an abundant and developmentally regulated PKC isoform in the brain, has been implicated in memory throughout life and across species. Yet, direct evidence for a mechanistic role for PKCɛ in memory is still lacking. Hence, we sought to evaluate this in rats, using short-term treatments with two PKCɛ-selective peptides, the inhibitory ɛV1-2 and the activating ψɛRACK, and the novel object recognition task (NORT). Our results show that the PKCɛ-selective activator ψɛRACK, did not have a significant effect on recognition memory. In the short time frames used, however, inhibition of PKCɛ activation with the peptide inhibitor ɛV1-2 significantly impaired recognition memory. Moreover, when we addressed at the molecular level the immediate proximal signalling events of PKCɛ activation in acutely dissected rat hippocampi, we found that ψɛRACK increased in a time-dependent manner phosphorylation of MARCKS and activation of Src, Raf, and finally ERK1/2, whereas ɛV1-2 inhibited all basal activity of this pathway. Taken together, these findings present the first direct evidence that PKCɛ activation is an essential molecular component of recognition memory and point toward the use of systemically administered PKCɛ-regulating peptides as memory study tools and putative therapeutic agents. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  12. Wnt/β-catenin signaling is required for distraction osteogenesis in rats.

    Science.gov (United States)

    Wang, Xuemei; Luo, En; Bi, Ruiye; Ye, Bin; Hu, Jing; Zou, Shujuan

    2018-01-01

    The Wnt signaling pathway plays crucial roles in embryonic skeletal development and postnatal bone regeneration. However, mechanisms of Wnt signaling functioning in distraction osteogenesis (DO) haven't been well characterized. We established a DO model using Sprague-Dawley rat tibia. And a Wnt signaling blocking agent, recombinant rat Dickkopf-related protein 1 (rrDkk1), was locally applied in the distracted gap to study the role of Wnt signaling during DO process. Animals in the experimental group received rrDkk1 injections (dose = 25 μg/kg) once daily during distraction period and every third day during consolidation stage (n = 48). Animals in the control group received saline under the same injection strategy (n = 48). Animals at different time points during DO process (1, 3, 6, 12 days after distraction, 10 days and 6 weeks after consolidation) were killed and tissues in the distraction region were harvested for radiography, dual energy X-ray absorptiometry, micro-computed tomography (micro-CT), and histological analyses. Most Wnt ligands, cofactors, receptors, and antagonists were widely expressed in the distraction callus and were significantly upregulated during DO process. After rrDkk1 administration, the majority of these factors were downregulated at the mRNA level, except sFRP and GSK-3β. At the protein level, both β-catenin and Lef-1 were also suppressed by rrDkk1. In the long term, restricted bone healing was observed in the distracted callus in the rrDkk1 injection group. These findings were confirmed by histological and micro-CT analyses. Our findings suggest that Wnt signaling participates in the process of DO, and clinical therapeutic approaches of DO may do well to avoid Wnt pathway suppression.

  13. Who Are the Subjects with Gambling-Related Problems Requiring Treatment? A Study in Northern Italy

    Science.gov (United States)

    Fioritti, Angelo; Marani, Silvia; Gambini, Daniele; Turino, Elsa; Piazza, Antonella

    2018-01-01

    Background: This study analyzes data related to Hospital (HOS), Public Treatment Service Dedicated to Drug Addicts (SERD), or Community Mental Health Center (CMHC) clients with a first diagnosis of Pathological Gambling (PG) in the period 2000/2016 in Northern Italy. The aims were to describe trends and characteristics of pathological gamblers (PGs) and to estimate the prevalence of other diagnoses before or after the diagnosis of PG. Methods: Participants aged over 17 years with an ICD-9 or ICD-10 PG diagnosis were selected. Results: 680 PGs were identified, mean age 47.4 years, 20% female, 13% non-natives, 30% had other mental disorders diagnoses, 9% had alcohol dependence syndrome, and 11% had drug dependence. Most participants with comorbid disorders were diagnosed before PG, with a more elevated prevalence regarding mental disorders. Almost seven years had elapsed on average between the first admission and the diagnosis of PG. Conclusions: The results of this study highlight a growing demand for PG treatment addressed not only to SERD, but also to psychiatric and hospital services, based on the increase in SERD attendance from 2013. Many of them had already been treated for mental health problems before, but their percentage remained costant over time. PMID:29652821

  14. [Consequences of obesity in children and teenagers: a problem that requires attention].

    Science.gov (United States)

    Liria, Reyna

    2012-01-01

    Obesity is a worldwide pandemic and children are a vulnerable group. In America, it was estimated that in 2010, 15.2% of 18 year-old children could suffer from this. Obesity in children and teenagers has a negative impact on health and on the load of diseases at this stage of life, and later on in adulthood, having a negative impact on the economy of a country due to the rise of risks of chronic diseases, health expenses and indirect costs as a result of the disease. Peru is going through an epidemiological transition, with unsolved malnutrition problems and high child obesity rates (10% of children under five), thus being one of the countries with a higher increase of child obesity in recent years in Latin America. Childhood and adolescence are considered critical periods because eating habits and physical activity start at this point; and because most obese children and teenagers will maintain those habits until they reach adulthood. For this reason, it is essential to seek strategies and interventions that prevent overweight and obesity among children and teenagers in order to improve the health conditions of a country.

  15. Who Are the Subjects with Gambling-Related Problems Requiring Treatment? A Study in Northern Italy

    Directory of Open Access Journals (Sweden)

    Raimondo Maria Pavarin

    2018-04-01

    Full Text Available Background: This study analyzes data related to Hospital (HOS, Public Treatment Service Dedicated to Drug Addicts (SERD, or Community Mental Health Center (CMHC clients with a first diagnosis of Pathological Gambling (PG in the period 2000/2016 in Northern Italy. The aims were to describe trends and characteristics of pathological gamblers (PGs and to estimate the prevalence of other diagnoses before or after the diagnosis of PG. Methods: Participants aged over 17 years with an ICD-9 or ICD-10 PG diagnosis were selected. Results: 680 PGs were identified, mean age 47.4 years, 20% female, 13% non-natives, 30% had other mental disorders diagnoses, 9% had alcohol dependence syndrome, and 11% had drug dependence. Most participants with comorbid disorders were diagnosed before PG, with a more elevated prevalence regarding mental disorders. Almost seven years had elapsed on average between the first admission and the diagnosis of PG. Conclusions: The results of this study highlight a growing demand for PG treatment addressed not only to SERD, but also to psychiatric and hospital services, based on the increase in SERD attendance from 2013. Many of them had already been treated for mental health problems before, but their percentage remained costant over time.

  16. A Health Equity Problem for Low Income Children: Diet Flexibility Requires Physician Authorization.

    Science.gov (United States)

    Stookey, Jodi D

    2015-09-01

    USDA programs, such as the Child and Adult Care Food Program (CACFP), School Breakfast Program (SBP), and/or National School Lunch Program (NSLP), enable child care centers and schools to provide free and reduced price meals, daily, to millions of low income children. Despite intention to equalize opportunity for every child to have a healthy diet, USDA program rules may be contributing to child obesity disparities and health inequity. USDA program rules require child care centers and schools to provide meals that include a specified number of servings of particular types of foods and beverages. The rules are designed for the average, healthy weight child to maintain weight and growth. They are not designed for the underweight child to gain weight, obese child to normalize weight, or pre-diabetic child to avoid incident diabetes. The rules allow for only one meal pattern and volume, as opposed to a flexible spectrum of meal patterns and portion sizes. Parents of children who participate in the CACFP, SBP, and/or NSLP do not have control over the amount or composition of the subsidized meals. Parents of overweight, obese, or diabetic children who participate in the subsidized meal programs can request dietary change, special meals or accommodations to address their child's health status, but child care providers and schools are not required to comply with the request unless a licensed physician signs a "Medical statement to request special meals and/or accommodations". Although physicians are the only group authorized to change the foods, beverages, and portion sizes served daily to low income children, they are not doing so. Over the past three years, despite an overweight and obesity prevalence of 30% in San Francisco child care centers serving low income children, zero medical statements were filed to request special meals or accommodations to alter daily meals in order to prevent obesity, treat obesity, or prevent postprandial hyperglycemia. Low income children

  17. Phosphorylation of rat aquaporin-4 at Ser(111) is not required for channel gating

    DEFF Research Database (Denmark)

    Assentoft, Mette; Kaptan, Shreyas; Fenton, Robert A.

    2013-01-01

    Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4 is theref......Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4...... is therefore of therapeutic interest. Phosphorylation of some aquaporins has been proposed to regulate their water permeability via gating of the channel itself. Protein kinase (PK)-dependent phosphorylation of Ser(111) has been reported to increase the water permeability of AQP4 expressed in an astrocytic...... of activators and inhibitors of PKG and PKA. Mutation of Ser(111) to alanine or aspartate (to prevent or mimic phosphorylation) did not change the water permeability of AQP4. PKG activation had no effect on the water permeability of AQP4 in primary cultures of rat astrocytes. Molecular dynamics simulations...

  18. Development of a Preventive HIV Vaccine Requires Solving Inverse Problems Which Is Unattainable by Rational Vaccine Design

    Directory of Open Access Journals (Sweden)

    Marc H. V. Van Regenmortel

    2018-01-01

    Full Text Available Hypotheses and theories are essential constituents of the scientific method. Many vaccinologists are unaware that the problems they try to solve are mostly inverse problems that consist in imagining what could bring about a desired outcome. An inverse problem starts with the result and tries to guess what are the multiple causes that could have produced it. Compared to the usual direct scientific problems that start with the causes and derive or calculate the results using deductive reasoning and known mechanisms, solving an inverse problem uses a less reliable inductive approach and requires the development of a theoretical model that may have different solutions or none at all. Unsuccessful attempts to solve inverse problems in HIV vaccinology by reductionist methods, systems biology and structure-based reverse vaccinology are described. The popular strategy known as rational vaccine design is unable to solve the multiple inverse problems faced by HIV vaccine developers. The term “rational” is derived from “rational drug design” which uses the 3D structure of a biological target for designing molecules that will selectively bind to it and inhibit its biological activity. In vaccine design, however, the word “rational” simply means that the investigator is concentrating on parts of the system for which molecular information is available. The economist and Nobel laureate Herbert Simon introduced the concept of “bounded rationality” to explain why the complexity of the world economic system makes it impossible, for instance, to predict an event like the financial crash of 2007–2008. Humans always operate under unavoidable constraints such as insufficient information, a limited capacity to process huge amounts of data and a limited amount of time available to reach a decision. Such limitations always prevent us from achieving the complete understanding and optimization of a complex system that would be needed to achieve a truly

  19. Job requirements compared to medical school education: differences between graduates from problem-based learning and conventional curricula.

    Science.gov (United States)

    Schlett, Christopher L; Doll, Hinnerk; Dahmen, Janosch; Polacsek, Ole; Federkeil, Gero; Fischer, Martin R; Bamberg, Fabian; Butzlaff, Martin

    2010-01-14

    Problem-based Learning (PBL) has been suggested as a key educational method of knowledge acquisition to improve medical education. We sought to evaluate the differences in medical school education between graduates from PBL-based and conventional curricula and to what extent these curricula fit job requirements. Graduates from all German medical schools who graduated between 1996 and 2002 were eligible for this study. Graduates self-assessed nine competencies as required at their day-to-day work and as taught in medical school on a 6-point Likert scale. Results were compared between graduates from a PBL-based curriculum (University Witten/Herdecke) and conventional curricula. Three schools were excluded because of low response rates. Baseline demographics between graduates of the PBL-based curriculum (n = 101, 49% female) and the conventional curricula (n = 4720, 49% female) were similar. No major differences were observed regarding job requirements with priorities for "Independent learning/working" and "Practical medical skills". All competencies were rated to be better taught in PBL-based curriculum compared to the conventional curricula (all p learning/working" (Delta + 0.57), "Psycho-social competence" (Delta + 0.56), "Teamwork" (Delta + 0.39) and "Problem-solving skills" (Delta + 0.36), whereas "Research competence" (Delta--1.23) and "Business competence" (Delta--1.44) in the PBL-based curriculum needed improvement. Among medical graduates in Germany, PBL demonstrated benefits with regard to competencies which were highly required in the job of physicians. Research and business competence deserve closer attention in future curricular development.

  20. Job requirements compared to medical school education: differences between graduates from problem-based learning and conventional curricula

    Directory of Open Access Journals (Sweden)

    Federkeil Gero

    2010-01-01

    Full Text Available Abstract Background Problem-based Learning (PBL has been suggested as a key educational method of knowledge acquisition to improve medical education. We sought to evaluate the differences in medical school education between graduates from PBL-based and conventional curricula and to what extent these curricula fit job requirements. Methods Graduates from all German medical schools who graduated between 1996 and 2002 were eligible for this study. Graduates self-assessed nine competencies as required at their day-to-day work and as taught in medical school on a 6-point Likert scale. Results were compared between graduates from a PBL-based curriculum (University Witten/Herdecke and conventional curricula. Results Three schools were excluded because of low response rates. Baseline demographics between graduates of the PBL-based curriculum (n = 101, 49% female and the conventional curricula (n = 4720, 49% female were similar. No major differences were observed regarding job requirements with priorities for "Independent learning/working" and "Practical medical skills". All competencies were rated to be better taught in PBL-based curriculum compared to the conventional curricula (all p Conclusion Among medical graduates in Germany, PBL demonstrated benefits with regard to competencies which were highly required in the job of physicians. Research and business competence deserve closer attention in future curricular development.

  1. Increase in tartrate-resistant acid phosphatase of bone at the early stage of ascorbic acid deficiency in the ascorbate-requiring Osteogenic Disorder Shionogi (ODS) rat.

    Science.gov (United States)

    Goto, A; Tsukamoto, I

    2003-08-01

    The effect of ascorbic acid deficiency on bone metabolism was evaluated using the ascorbate-requiring Osteogenic Disorder Shionogi (ODS) rat model. Ascorbic acid (Asc)-deficient rats gained body weight in a manner similar to Asc-supplemented rats (control) during 3 weeks, but began to lose weight during the 4th week of Asc deficiency. The tartrate-resistant acid phosphatase (TRAP) activity in serum increased to about 2-fold the control value in the rats fed the Asc-free diet for 2, 3, and 4 weeks (AscD2, AscD3, and AscD4), while a decrease in the alkaline phosphatase (ALP) activity was observed only in AscD4 rats. The serum pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) level significantly increased to 1.3-, 1.4-, and 1.9-fold of that in the controls in AscD2, D3, and D4, respectively. The ALP activity in the distal femur was unchanged in AscD1, D2, and D3, but decreased to 50% of the control level in AscD4 rats. The TRAP activity in the distal femur increased to about 2-fold of that in the controls in the AscD2 and D3 and decreased to the control level in the AscD4 rats. The amount of hydroxyproline in the distal femur significantly decreased to about 80%, 70%, and 60% of the control in AscD2, D3, and D4 rats, respectively. These decreases were associated with a similar reduction in the calcium content of the distal femur. Histochemical analysis of the distal femur showed an increase in TRAP-positive cells in AscD2 and AscD3 rats and a decrease in the trabecular bone in AscD2, D3, and D4 rats. These results suggested that a deficiency of Asc stimulated bone resorption at an early stage, followed by a decrease in bone formation in mature ODS rats which already had a well-developed collagen matrix and fully differentiated osteoblasts.

  2. Steroid modulation of the chloride ionophore in rat brain: structure-activity requirements, regional dependence and mechanism of action

    Energy Technology Data Exchange (ETDEWEB)

    Gee, K.W.; Bolger, M.B.; Brinton, R.E.; Coirini, H.; McEwen, B.S.

    1988-08-01

    Further in vitro studies of steroids active at the gamma-aminobutyric acidA (GABAA) receptor regulated Cl- channel labeled by (35S)-t-butylbicyclophosphorothionate ((35S)TBPS) reveal additional structural requirements necessary for activity. Evaluation of selected steroids for activity against TBPS-induced convulsions show similar requirements for activity. Interestingly, steroids (e.g., 5 alpha-pregnan-3 alpha, 20 alpha-diol) were identified that have high potency but limited efficacy as modulators of (35S)TBPS binding. These characteristics are reminiscent of the clinically useful benzodiazepines (BZs) such as clonazepam. However, interactions between the prototypical anesthetic-barbiturate, sodium pentobarbital, and steroids active at the Cl- channel suggest that they do not share a common site of action as allosteric modulators of (35S)TBPS and BZ receptor binding. The most potent steroid evaluated, 5 alpha-pregnan-3 alpha-ol-20-one, modulates (35S)TBPS binding at low concentrations (IC50 approximately 17 nM) in a regionally dependent manner. All (35S)TBPS binding sites appear to be functionally coupled to a steroid modulatory site. Because several of the active steroids are metabolites of progesterone, their ability to inhibit the binding of (3H)promegestrone to the cytosolic progestin receptor in rat uterus was evaluated. Those steroids showing potent activity at the GABAA receptor-Cl- ionophore were inactive at the intracellular progestin receptor. Such specificity coupled with their high potency provide additional support for the hypothesis that some of these steroids may be involved in the homeostatic regulation of brain excitability via the GABAA-BZ receptor complex.

  3. Cystathionine-β-synthase-derived hydrogen sulfide is required for amygdalar long-term potentiation and cued fear memory in rats.

    Science.gov (United States)

    Chen, Hai-Bo; Wu, Wen-Ning; Wang, Wei; Gu, Xun-Hu; Yu, Bin; Wei, Bo; Yang, Yuan-Jian

    2017-04-01

    Hydrogen sulfide (H 2 S) is an endogenous gaseous molecule that functions as a neuromodulator in the brain. We previously reported that H 2 S regulated amygdalar synaptic plasticity and cued fear memory in rats. However, whether endogenous H 2 S is required for amygdalar long-term potentiation (LTP) induction and cued fear memory formation remains unclear. Here, we show that cystathionine-β-synthase (CBS), the predominant H 2 S-producing enzyme in the brain, was highly expressed in the amygdala of rats. Suppressing CBS activity by inhibitor prevented activity-triggered generation of H 2 S in the lateral amygdala (LA) region. Incubating brain slices with CBS inhibitor significantly prevented the induction of NMDA receptors (NMDARs)-dependent LTP in the thalamo-LA pathway, and intra-LA infusion of CBS inhibitor impaired cued fear memory in rats. Notably, treatment with H 2 S donor, but not CBS activator, significantly reversed the impairments of LTP and fear memory caused by CBS inhibition. Mechanismly, inhibition of CBS activity led to a reduction in NMDAR-mediated synaptic response in the thalamo-LA pathway, and treatment with H 2 S donor restored the function of NMDARs. Collectively, these results indicate that CBS-derived H 2 S is required for amygdalar synaptic plasticity and cued fear memory in rats, and the effects of endogenous H 2 S might involve the regulation of NMDAR function. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Normative data for Chinese compound remote associate problems.

    Science.gov (United States)

    Wu, Ching-Lin; Chen, Hsueh-Chih

    2017-12-01

    The Remote Associates Test (RAT) is a well-known measure of creativity, with each item on the RAT is composed of three unrelated stimulus words. The participant's task is to find an answer in the form of a word that could combine with each of the stimulus words, thus forming three new actual nouns. Researchers have modified the RAT to develop compound remote associate problems that emphasize combining vocabulary to form compound words. In the field of creativity research for Mandarin speakers, the Chinese RAT has been widely applied for over 10 years. The original RAT, compound remote associate problems, and Chinese RAT have various common advantages, such as being convenient to use and having objective scoring; additionally, the development of items for certain tests is easy and satisfies the requirements of psychological assessments in terms of the quantity of items. Currently, many language editions of the RAT and compound remote associate problems already exist. In particular, the English and Italian versions of these tests already have derived normative data. Because approximately 20% of the world's population are native Mandarin speakers, and because increasing numbers of people are choosing Mandarin as a second language, the need to increase Mandarin-language resources is growing; however, normative data for the Chinese RAT still do not exist. To address this issue, in the present study we developed Chinese compound remote associate problems and analyzed the passing rates by items, problem solving times, and various normative data, using the responses of 253 subjects in three experiments.

  5. Requirements of glycerol and fatty acid for triglyceride synthesis and ketogenesis by hepatocytes from normal and triiodothyronine-treated rats

    International Nuclear Information System (INIS)

    Olubadewo, J.O.; Heimberg, M.

    1985-01-01

    Hepatocytes from T3-treated rats synthesized less triglyceride and more ketone bodies from [1- 14 C]oleate at all concentrations from 0-2 mM, than did hepatocytes from euthyroid animals; addition of 1.0 mM glycerol increased triglyceride synthesis and reduced ketogenesis in hepatocytes from T3-treated rats to the rates observed in euthyroid hepatocytes in the absence of added glycerol. Glycerol did not alter triglyceride synthesis, but reduced ketogenesis genesis by euthyroid hepatocytes. It is probable from these and other data that, in the hyperthyroid rat, glycero-3-P, and not fatty acid, is rate limiting for synthesis of triglyceride, and, secondarily for reducing rates of ketogenesis in the hepatocyte

  6. Rat embryo fibroblasts require both the cell-binding and the heparin-binding domains of fibronectin for survival

    DEFF Research Database (Denmark)

    Jeong, J; Han, I; Lim, Y

    2001-01-01

    of the cell-binding domain of FN with integrin is sufficient to rescue rat embryo fibroblasts (REFs) from detachment-induced apoptosis. REFs attached and spread normally after plating on substrates coated with either intact FN or a FN fragment, FN120, that contains the cell-binding domain but lacks the C...

  7. Thyroid hormone receptor binds to a site in the rat growth hormone promoter required for induction by thyroid hormone

    International Nuclear Information System (INIS)

    Koenig, R.J.; Brent, G.A.; Warne, R.L.; Larsen, P.R.; Moore, D.D.

    1987-01-01

    Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. The authors have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. They show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor

  8. Hemiequilibrium problems

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2004-01-01

    Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.

  9. Cytoplasmic vacuolation in cultured rat astrocytes induced by an organophosphorus agent requires extracellular signal-regulated kinase activation

    International Nuclear Information System (INIS)

    Isobe, Ichiro; Maeno, Yoshitaka; Nagao, Masataka; Iwasa, Mineo; Koyama, Hiroyoshi; Seko-Nakamura, Yoshimi; Monma-Ohtaki, Jun

    2003-01-01

    There are various toxic chemicals that cause cell death. However, in certain cases deleterious agents elicit various cellular responses prior to cell death. To determine the cellular mechanisms by which such cellular responses are induced is important, but sufficient attention has not been paid to this issue to date. In this study, we showed the characteristic effects of an organophosphorus (OP) agent, bis(pinacolyl methyl)phosphonate (BPMP), which we synthesized for the study of OP nerve agents, on cultured rat astrocytes. Morphologically, BPMP induced cytoplasmic vacuolation and stellation in the rat astrocytes. Cytoplasmic vacuolation is a cell pathological change observed, for example, in vacuolar degeneration, and stellation has been reported in astrocytic reactions against various stimuli. By pretreatment with cycloheximide, a protein synthesis inhibitor, stellation was inhibited, although vacuolation was not. Cell staining with a mitochondrion-selective dye indicated that the vacuolation probably occurs in the mitochondria that are swollen and vacuolatred in the center. Interestingly, the extracellular signal-regulated kinase (ERK) cascade inhibitor inhibited vacuolation and, to some extent, stellation. These results suggest that the ERK signaling cascade is important for the induction of mitochondrial vacuolation. We expect that a detailed study of these astrocytic reactions will provide us new perspectives regarding the variation and pathological significance of cell morphological changes, such as vacuolar degeneration, and also the mechanisms underlying various neurological disorders

  10. Mechanical problems in turbomachines, steam and gas turbines. Large steam turbine manufacturing requirements to fulfill customer needs for electric power

    International Nuclear Information System (INIS)

    Brazzini, R.

    1975-01-01

    The needs of the customers in large steam turbines for electric power are examined. The choices and decisions made by the utility about the equipments are dealt with after considering the evolution of power demand on the French network. These decisions and choices mainly result from a technical and economic optimization of production equipments: choice of field-proven solutions, trend to lower steam characteristics, trend to higher output of the units (i.e. size effect), spreading out standardization of machines and components (policy of technical as well as technological levels, i.e. mass production effect). Standardization of external characteristics of units of same level of output and even standardization of some main components. The requirements turbine manufacturers have to meet may fall in two categories: on one side: gaining experience and know-how, capability of making high quality experiments, out put capacity, will to hold a high efficiency level; on the other side: meeting the technical requirements related to the contracts. Among these requirements, one can differentiate those dealing with the service expected from the turbine and that resulting in the responsibility limits of the manufacturer and those tending to gain interchangeability, to improve availability of the equipment, to increase safety, and to make operation and maintenance easier [fr

  11. Norepinephrine-evoked salt-sensitive hypertension requires impaired renal sodium chloride cotransporter activity in Sprague-Dawley rats.

    Science.gov (United States)

    Walsh, Kathryn R; Kuwabara, Jill T; Shim, Joon W; Wainford, Richard D

    2016-01-15

    Recent studies have implicated a role of norepinephrine (NE) in the activation of the sodium chloride cotransporter (NCC) to drive the development of salt-sensitive hypertension. However, the interaction between NE and increased salt intake on blood pressure remains to be fully elucidated. This study examined the impact of a continuous NE infusion on sodium homeostasis and blood pressure in conscious Sprague-Dawley rats challenged with a normal (NS; 0.6% NaCl) or high-salt (HS; 8% NaCl) diet for 14 days. Naïve and saline-infused Sprague-Dawley rats remained normotensive when placed on HS and exhibited dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide. NE infusion resulted in the development of hypertension, which was exacerbated by HS, demonstrating the development of the salt sensitivity of blood pressure [MAP (mmHg) NE+NS: 151 ± 3 vs. NE+HS: 172 ± 4; P salt-sensitive animals, increased NE prevented dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide, suggesting impaired NCC activity contributes to the development of salt sensitivity [peak natriuresis to hydrochlorothiazide (μeq/min) Naïve+NS: 9.4 ± 0.2 vs. Naïve+HS: 7 ± 0.1; P salt-sensitive component of NE-mediated hypertension, while chronic ANG II type 1 receptor antagonism significantly attenuated NE-evoked hypertension without restoring NCC function. These data demonstrate that increased levels of NE prevent dietary sodium-evoked suppression of the NCC, via an ANG II-independent mechanism, to stimulate the development of salt-sensitive hypertension. Copyright © 2016 the American Physiological Society.

  12. Situation of the medical physics in the Republic of Argentina. Regulatory problem linked to the requirement of physic specialists

    International Nuclear Information System (INIS)

    Arbor Gonzalez, A.; Larcher, A.; Blanco, S.

    2001-01-01

    This paper provides up-to-date data on the participation of medical physicists in current staffs for radiotherapy, nuclear medicine and diagnostic radiology in Argentina, and it presents projections on the academic education of specialists in the next five years. At the same time, the regulatory framework including the requirements for physicists staffing levels in medical practices is presented. This panorama permits to stick out the important role of the professional associations and the academic institutions in the development of Medical Physics in the country. (author)

  13. Depletion of rat cortical norepinephrine and the inhibition of [3H]norepinephrine uptake by xylamine does not require monoamine oxidase activity

    International Nuclear Information System (INIS)

    Dudley, M.W.

    1988-01-01

    Inhibition of monoamine oxidase A through pretreatment of rats with clorgyline or the pro-drug MDL 72,394 did not block the amine-depleting action of xylamine. Xylamine treatment resulted in a loss of approximately 60% of the control level of norepinephrine in the cerebral cortex. A 1-hr pretreatment, but not a 24-hr pretreatment, with the monoamine oxidase B inhibitor, L-deprenyl, prevented the depletion of norepinephrine by xylamine. In addition, pretreatment with MDL 72,974, a monoamine oxidase B inhibitor without amine-releasing or uptake - inhibiting effects, did not prevent cortical norepinephrine levels. Inhibition of monoamine oxidase by either MDL 72,974 or MDL 72,394 did not prevent the inhibition of [ 3 H]norepinephrine uptake into rat cortical synaptosomes by xylamine. These data indicate that monoamine oxidase does not mediate the amine-releasing or uptake inhibiting properties of xylamine. The protection afforded by L-deprenyl following a 1-hr pretreatment most probably was due to accumulation of its metabolite, L-amphetamine, which would inhibit the uptake carrier. A functional carrier is required for depletion since desipramine administered 1 hr prior to xylamine, was also able to prevent depletion of norepinephrine

  14. Liver diseases: A major, neglected global public health problem requiring urgent actions and large-scale screening.

    Science.gov (United States)

    Marcellin, Patrick; Kutala, Blaise K

    2018-02-01

    CLDs represent an important, and certainly underestimated, global public health problem. CLDs are highly prevalent and silent, related to different, sometimes associated causes. The distribution of the causes of these diseases is slowly changing, and within the next decade, the proportion of virus-induced CLDs will certainly decrease significantly while the proportion of NASH will increase. There is an urgent need for effective global actions including education, prevention and early diagnosis to manage and treat CLDs, thus preventing cirrhosis-related morbidity and mortality. Our role is to increase the awareness of the public, healthcare professionals and public health authorities to encourage active policies for early management that will decrease the short- and long-term public health burden of these diseases. Because necroinflammation is the key mechanism in the progression of CLDs, it should be detected early. Thus, large-scale screening for CLDs is needed. ALT levels are an easy and inexpensive marker of liver necroinflammation and could be the first-line tool in this process. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Actual problems of the antimonopoly requirements` observance in the bidding for the sale of land in the Russian Federation

    Directory of Open Access Journals (Sweden)

    Alexey Pavlovich ANISIMOV

    2013-06-01

    Full Text Available A comprehensive view of the topic of Antimonopoly regulation in the sphere of land auctions for the Russian legal science and legal science other Eastern European countries is highly relevant. The importance of such research is that foreign companies having business in Russia are not always aware of specificity in land tendering legal regulation and antimonopoly requirements in this sphere. Moreover, the practice of violation of antimonopoly legislation in the sphere of land tendering and probable means of legislation improvement may hereby present more interest for them. The authors cite and analyze various typical violations in the sphere of land tendering, including publication of land auctions notices in an improper printing agency; lack of applications registration and putting forward extra requirements towards the participants; display for land parcels auctions for which no technical specifications of networking have been determined and no payment for such networking has been established; attempts of local administration to provide land parcels without prior approval of the objects’ places of location and without auctions (though such a procedure is of an extremely local character and is only performed in cases expressly specified by the Federal Law; collection of extra and illegal fees from physical and legal entities for participation in auctions; tendering in cases when they are not to be carried out under the Law (gardening, haymaking; underpricing of a land parcel, etc. Eventually a conclusion is drawn on the effectiveness of auctions which shall be secured by establishing a legal procedure which details and definitely determines tendering regulations, requirements towards the participants and order of agreement’s conclusion. Control on the part of antimonopoly bodies, undoubtedly, allows forming barriers for dishonest participants of the auctions. The authors assume that it is rather difficult to achieve absence of mal-usage by

  16. Autonomous Vehicles Require Socio-Political Acceptance-An Empirical and Philosophical Perspective on the Problem of Moral Decision Making.

    Science.gov (United States)

    Bergmann, Lasse T; Schlicht, Larissa; Meixner, Carmen; König, Peter; Pipa, Gordon; Boshammer, Susanne; Stephan, Achim

    2018-01-01

    Autonomous vehicles, though having enormous potential, face a number of challenges. As a computer system interacting with society on a large scale and human beings in particular, they will encounter situations, which require moral assessment. What will count as right behavior in such situations depends on which factors are considered to be both morally justified and socially acceptable. In an empirical study we investigated what factors people recognize as relevant in driving situations. The study put subjects in several "dilemma" situations, which were designed to isolate different and potentially relevant factors. Subjects showed a surprisingly high willingness to sacrifice themselves to save others, took the age of potential victims in a crash into consideration and were willing to swerve onto a sidewalk if this saved more lives. The empirical insights are intended to provide a starting point for a discussion, ultimately yielding societal agreement whereby the empirical insights should be balanced with philosophical considerations.

  17. Autonomous Vehicles Require Socio-Political Acceptance—An Empirical and Philosophical Perspective on the Problem of Moral Decision Making

    Science.gov (United States)

    Bergmann, Lasse T.; Schlicht, Larissa; Meixner, Carmen; König, Peter; Pipa, Gordon; Boshammer, Susanne; Stephan, Achim

    2018-01-01

    Autonomous vehicles, though having enormous potential, face a number of challenges. As a computer system interacting with society on a large scale and human beings in particular, they will encounter situations, which require moral assessment. What will count as right behavior in such situations depends on which factors are considered to be both morally justified and socially acceptable. In an empirical study we investigated what factors people recognize as relevant in driving situations. The study put subjects in several “dilemma” situations, which were designed to isolate different and potentially relevant factors. Subjects showed a surprisingly high willingness to sacrifice themselves to save others, took the age of potential victims in a crash into consideration and were willing to swerve onto a sidewalk if this saved more lives. The empirical insights are intended to provide a starting point for a discussion, ultimately yielding societal agreement whereby the empirical insights should be balanced with philosophical considerations. PMID:29541023

  18. Autonomous Vehicles Require Socio-Political Acceptance—An Empirical and Philosophical Perspective on the Problem of Moral Decision Making

    Directory of Open Access Journals (Sweden)

    Lasse T. Bergmann

    2018-02-01

    Full Text Available Autonomous vehicles, though having enormous potential, face a number of challenges. As a computer system interacting with society on a large scale and human beings in particular, they will encounter situations, which require moral assessment. What will count as right behavior in such situations depends on which factors are considered to be both morally justified and socially acceptable. In an empirical study we investigated what factors people recognize as relevant in driving situations. The study put subjects in several “dilemma” situations, which were designed to isolate different and potentially relevant factors. Subjects showed a surprisingly high willingness to sacrifice themselves to save others, took the age of potential victims in a crash into consideration and were willing to swerve onto a sidewalk if this saved more lives. The empirical insights are intended to provide a starting point for a discussion, ultimately yielding societal agreement whereby the empirical insights should be balanced with philosophical considerations.

  19. Glutamate requires NMDA receptors to modulate alpha2 adrenoceptor in medulla oblongata cultured cells of newborn rats.

    Science.gov (United States)

    Marinho da Silva, Sergio; Carrettiero, Daniel C; Chadi, Débora R F

    2014-04-03

    α2 Adrenoceptors (α2-ARs) are important in regulating the central control of blood pressure in medulla oblongata. However, it is unclear how this receptor is modulated by different receptors, especially the glutamatergic. In the present study, we studied the influence of ionotropic glutamatergic receptors over the α2-ARs in cultured cells of the medulla oblongata of newborn rats. For this purpose, the protein level of the α2-ARs was assessed after administration to the cultured cells of glutamate (glu), the agonists NMDA and kainate (KA), the NMDA receptor antagonist MK801 and the KA receptor antagonist DNQX. Results indicate that the α2-AR protein levels were increased after the treatments with glu and NMDA, and the addition of MK801 to this treatment thwarted this increase. Notwithstanding the fact that KA did not alter the receptor protein level, the combined treatment of DNQX with glu prevented the α2-AR protein modulation. In conclusion, the present study suggests that ionotropic glutamatergic receptors could be related to the α2-AR protein regulation in the medulla oblongata. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Interaction between the nature of the information and the cognitive requirement of the task in problem solving in mice.

    Science.gov (United States)

    Wolff, Mathieu; Benhassine, Narimane; Costet, Pierre; Segu, Louis; Buhot, Marie-Christine

    2004-11-01

    The Morris water maze and the radial-arm maze are two of the most frequently employed behavioral tasks used to assess spatial memory in rodents. In this study, we describe two new behavioral tasks in a radial-arm water maze enabling to combine the advantages of the Morris water maze and the radial-arm maze. In both tasks, spatial and nonspatial learning was assessed and the only task parameter that varied was the nature of the information available which was either spatial (various distal extra-maze cues) or nonspatial (visual intra-maze patterns). In experiment 1, 129T2/Sv mice were able to learn three successive pairwise discriminations [(1) A+/B-, (2) B+/C-, (3) C+/A-] with the same efficiency in both modalities (i.e. spatial and nonspatial modalities). Probe-trials at the end of each of these discriminations revealed particular features of this transverse-patterning-like procedure. In experiment 2, another group of 129T2/Sv mice was submitted to a delayed matching-to-sample working memory task. Mice were able to learn the task and were then able to show resistance to temporal interference as long as 60 min in the spatial modality but they failed to acquire the task in the nonspatial modality. The fact that the nonspatial information was exactly the same in both experiments highlights the existence of an interaction between the cognitive requirements of the task and the nature of the information.

  1. Complex problems require complex solutions: the utility of social quality theory for addressing the Social Determinants of Health

    Directory of Open Access Journals (Sweden)

    Ward Paul R

    2011-08-01

    Full Text Available Abstract Background In order to improve the health of the most vulnerable groups in society, the WHO Commission on Social Determinants of Health (CSDH called for multi-sectoral action, which requires research and policy on the multiple and inter-linking factors shaping health outcomes. Most conceptual tools available to researchers tend to focus on singular and specific social determinants of health (SDH (e.g. social capital, empowerment, social inclusion. However, a new and innovative conceptual framework, known as social quality theory, facilitates a more complex and complete understanding of the SDH, with its focus on four domains: social cohesion, social inclusion, social empowerment and socioeconomic security, all within the same conceptual framework. This paper provides both an overview of social quality theory in addition to findings from a national survey of social quality in Australia, as a means of demonstrating the operationalisation of the theory. Methods Data were collected using a national random postal survey of 1044 respondents in September, 2009. Multivariate logistic regression analysis was conducted. Results Statistical analysis revealed that people on lower incomes (less than $45000 experience worse social quality across all of the four domains: lower socio-economic security, lower levels of membership of organisations (lower social cohesion, higher levels of discrimination and less political action (lower social inclusion and lower social empowerment. The findings were mixed in terms of age, with people over 65 years experiencing lower socio-economic security, but having higher levels of social cohesion, experiencing lower levels of discrimination (higher social inclusion and engaging in more political action (higher social empowerment. In terms of gender, women had higher social cohesion than men, although also experienced more discrimination (lower social inclusion. Conclusions Applying social quality theory allows

  2. Polyclonal activation of rat B cells. I. A single mitogenic signal can stimulate proliferation, but three signals are required for differentiation

    International Nuclear Information System (INIS)

    Stunz, L.L.; Feldbush, T.L.

    1986-01-01

    A water-soluble, proteinaceous preparation derived from the cell walls of Salmonella typhimurium Re mutants has recently been tested in this laboratory for its ability to act as a mitogen for rat lymphocytes. This preparation (STM) has been found to be a potent simulator of B lymphocyte proliferation, as measured both by 3 H-TdR incorporation and by cell cycle analysis performed with flow cytofluorometry. STM stimulates approximately 50% of rat B cells to enter cycle. Previous investigations by others have shown that at least two sets of signals are required for B cell differentiation; (a) proliferation signals that may consist of both a stimulator of B cell conversion from G 0 to G 1 and growth factors, and (b) differentiation signals that probably include at least two B cell differentiation factors (BCDF). When STM was tested in a differentiation system it did not drive purified B cells to differentiate to PFC, either alone or when supplemented with a supernatant from concanavalin A-stimulated spleen cells (CAS). However, when both CAS and dextran sulfate (DXS) were supplied to the STM-stimulated cells, a large number of PFC resulted. DXT does not act by stimulating an additional, CAS-responsive B cell subset, since it has only a marginal effect upon 3 H-TdR uptake and does not increase the number of B cells in cycle when used together with STM. The authors that the two agents may be acting sequentially: STM stimulates the B cells to proliferate, and DXS drives the proliferating cells to become responsive to CAS. This suggests that the signals for B cell differentiation must consist of at least three activities: a trigger to stimulate the cells to proliferate, a factor to drive the cells to a BCDF-responsive state, and a BCDF that can drive the cells to secrete antibody

  3. Adenovirus type 9 E4 open reading frame 1 encodes a transforming protein required for the production of mammary tumors in rats.

    OpenAIRE

    Javier, R T

    1994-01-01

    The E4 region of human adenovirus type 9 (Ad9) transforms established rat embryo fibroblasts and encodes an essential determinant for the production of estrogen-dependent mammary tumors in rats. Testing of the seven Ad9 E4 open reading frames (ORFs) individually for transformation of the established rat embryo fibroblast cell line CREF indicated that only Ad9 E4 ORF1 possessed a significant ability to generate transformed foci on these cells. In contrast, the E4 ORF1 sequences from human Ad5 ...

  4. Distinct accessory cell requirements define two types of rat T cell hybridomas specific for unique determinants in the encephalitogenic 68-86 region of myelin basic protein

    International Nuclear Information System (INIS)

    Mannie, M.D.; Paterson, P.Y.; Thomas, D.W.; Nairn, R.

    1990-01-01

    Six clonotypically unique T cell hybridomas from Lewis rats were used to study accessory cell activities required for class II MHC restricted T cell responses to the 68-86 encephalitogenic sequence of myelin basic protein (MBP). T cell hybrids which were cultured with GP68-86 68-86 sequence of guinea pig MBP (GPMBP) and naive splenocytes (SPL) were induced to produce IL-2 as measured by the CTLL indicator cell line. The hybrids were categorized into two subsets (designated THYB-1 and THYB-2), because two distinct subset-specific pathways of communication between accessory cells and T cells were involved in GPMBP-induced IL-2 production. These pathways were distinguished by the following six observations. First, when the duration of a pulse of SPL with GPMBP was lengthened from 1 to 4 h, these SPL lost their ability to induce IL-2 production by THYB-2 hybrids yet nevertheless retained full stimulatory activity for THYB-1 hybrids. Second, paraformaldehyde fixation of GPMBP-pulsed SPL abrogated an activity necessary for Ag-induced IL-2 production by THYB-2 hybrids. These fixed SPL were nevertheless able to stimulate THYB-1 hybrids, albeit to a lesser extent than viable unfixed SPL. Third, the addition of either cycloheximide, cytochalasin B, or 2-deoxyglucose to an Ag pulse of SPL with GPMBP dramatically inhibited the subsequent responses of THYB-2 hybrids yet had little or no effect upon the reactivity of THYB-1 hybrids. Fourth, thymocytes lacked necessary activities for GPMBP evoked IL-2 production by THYB-2 hybrids yet strongly promoted THYB-1 hybrid responses. Fifth, exposure of SPL to as little as 500 rad of gamma-irradiation markedly attenuated THYB-2 hybrid response to GPMBP but did not affect THYB-1 responses. Sixth, anti-GPMBP responses by THYB-2 hybrids were observed only in the presence of both radioresistant adherent SPL and a distinct population of radiosensitive nonadherent SPL

  5. Glucose-Dependent Insulin Secretion in Pancreatic β-Cell Islets from Male Rats Requires Ca2+ Release via ROS-Stimulated Ryanodine Receptors.

    Directory of Open Access Journals (Sweden)

    Paola Llanos

    Full Text Available Glucose-stimulated insulin secretion (GSIS from pancreatic β-cells requires an increase in intracellular free Ca2+ concentration ([Ca2+]. Glucose uptake into β-cells promotes Ca2+ influx and reactive oxygen species (ROS generation. In other cell types, Ca2+ and ROS jointly induce Ca2+ release mediated by ryanodine receptor (RyR channels. Therefore, we explored here if RyR-mediated Ca2+ release contributes to GSIS in β-cell islets isolated from male rats. Stimulatory glucose increased islet insulin secretion, and promoted ROS generation in islets and dissociated β-cells. Conventional PCR assays and immunostaining confirmed that β-cells express RyR2, the cardiac RyR isoform. Extended incubation of β-cell islets with inhibitory ryanodine suppressed GSIS; so did the antioxidant N-acetyl cysteine (NAC, which also decreased insulin secretion induced by glucose plus caffeine. Inhibitory ryanodine or NAC did not affect insulin secretion induced by glucose plus carbachol, which engages inositol 1,4,5-trisphosphate receptors. Incubation of islets with H2O2 in basal glucose increased insulin secretion 2-fold. Inhibitory ryanodine significantly decreased H2O2-stimulated insulin secretion and prevented the 4.5-fold increase of cytoplasmic [Ca2+] produced by incubation of dissociated β-cells with H2O2. Addition of stimulatory glucose or H2O2 (in basal glucose to β-cells disaggregated from islets increased RyR2 S-glutathionylation to similar levels, measured by a proximity ligation assay; in contrast, NAC significantly reduced the RyR2 S-glutathionylation increase produced by stimulatory glucose. We propose that RyR2-mediated Ca2+ release, induced by the concomitant increases in [Ca2+] and ROS produced by stimulatory glucose, is an essential step in GSIS.

  6. Deletion of a conserved regulatory element required for Hmx1 expression in craniofacial mesenchyme in the dumbo rat: a newly identified cause of congenital ear malformation

    Directory of Open Access Journals (Sweden)

    Lely A. Quina

    2012-11-01

    Hmx1 is a homeodomain transcription factor expressed in the developing eye, peripheral ganglia, and branchial arches of avian and mammalian embryos. Recent studies have identified a loss-of-function allele at the HMX1 locus as the causative mutation in the oculo-auricular syndrome (OAS in humans, characterized by ear and eye malformations. The mouse dumbo (dmbo mutation, with similar effects on ear and eye development, also results from a loss-of-function mutation in the Hmx1 gene. A recessive dmbo mutation causing ear malformation in rats has been mapped to the chromosomal region containing the Hmx1 gene, but the nature of the causative allele is unknown. Here we show that dumbo rats and mice exhibit similar neonatal ear and eye phenotypes. In midgestation embryos, dumbo rats show a specific loss of Hmx1 expression in neural-crest-derived craniofacial mesenchyme (CM, whereas Hmx1 is expressed normally in retinal progenitors, sensory ganglia and in CM, which is derived from mesoderm. High-throughput resequencing of 1 Mb of rat chromosome 14 from dmbo/dmbo rats, encompassing the Hmx1 locus, reveals numerous divergences from the rat genomic reference sequence, but no coding changes in Hmx1. Fine genetic mapping narrows the dmbo critical region to an interval of ∼410 kb immediately downstream of the Hmx1 transcription unit. Further sequence analysis of this region reveals a 5777-bp deletion located ∼80 kb downstream in dmbo/dmbo rats that is not apparent in 137 other rat strains. The dmbo deletion region contains a highly conserved domain of ∼500 bp, which is a candidate distal enhancer and which exhibits a similar relationship to Hmx genes in all vertebrate species for which data are available. We conclude that the rat dumbo phenotype is likely to result from loss of function of an ultraconserved enhancer specifically regulating Hmx1 expression in neural-crest-derived CM. Dysregulation of Hmx1 expression is thus a candidate mechanism for congenital ear

  7. Diagnosing plant problems

    Science.gov (United States)

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  8. Conditions required for the appearance of double responses in hippocampal field CA1 to application of single stimuli to Shäffer collaterals in freely moving rats.

    Science.gov (United States)

    Zosimovskii, V A; Korshunov, V A; Markevich, V A

    2008-03-01

    Stimulation of Shäffer collaterals with single current impulses could evoke double responses in hippocampal field CA1 in freely moving rats. The late response - the population excitatory postsynaptic potential with a preceding transient potential, often biphasic - occurred only after an early population spike and was time-locked to it. The shape characteristics of the late response, its polarity, and its latent period relative to the early population spike suggest that stimulation of Shäffer collaterals gives rise, in CA1, to a wave of excitation which passes through the entorhinal cortex and returns to CA1 directly via fibers of the perforant path. In conscious rats, medium-strength stimulation of Shäffer collaterals, sufficient to evoke a quite early population spike in CA1, did not usually lead to the appearance of a late response; the same stimulation became effective after tetanization of Shäffer collaterals in conditions of long-term potentiation of the early population spike. Furthermore, the appearance of the late response was facilitated in rats falling asleep on the background of high-amplitude, low-frequency EEG oscillations in CA1 characteristic of slow-wave sleep, as well as in sleeping rats, regardless of the EEG pattern.

  9. [Conditions required for appearance of a double response to a single-shock stimulation of Schaffer collaterals in hippocampal field CA1 in freely moving rats].

    Science.gov (United States)

    Zosimovskiĭ, V A; Korshunov, V A; Markevich, V A

    2007-01-01

    Schaffer collateral stimulation with a single current impulse can evoke a double response in hippocampal field CA1 of freely moving rats. The late response appears as a population excitatory postsynaptic potential with a preceding short-term potential (frequently biphasic) only after the early population spike and is time-locked to it. The wave shape and polarity of the late response, its latency with respect to the peak of the early population spike suggest that the excitation wave produced in the CA1 field by the stimulation of Schaffer collaterals passes across the entorhinal cortex and returns to the CA1 directly via the perforant path fibers. In waking rat, the medium-intensity stimulation of Schaffer collaterals (able to evoke in the CA1 an early population spike of sufficiently high amplitude) usually does not result in the appearance of the late response. However, similar stimulation becomes efficient after the tetanization of Schaffer collaterals, under conditions of the long-term potentiation of the early population spike. Moreover, the late response occurrence is facilitated in a rat falling asleep after the development in the CA1 of high-amplitude low-frequency EEG oscillations typical for the slow-wave sleep and in a sleeping rat independently of the EEG pattern.

  10. Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells.

    Science.gov (United States)

    Massey, Katherine J; Li, Quanwen; Rossi, Noreen F; Keezer, Susan M; Mattingly, Raymond R; Yingst, Douglas R

    2016-02-01

    How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser(938) were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K · mg protein(-1) · min(-1) and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser(938) is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells.

  11. Effects of the hepatocarcinogen nafenopin, a peroxisome proliferator, on the activities of rat liver glutathione-requiring enzymes and catalase in comparison to the action of phenobarbital.

    Science.gov (United States)

    Furukawa, K; Numoto, S; Furuya, K; Furukawa, N T; Williams, G M

    1985-10-01

    The biochemical effects in the livers of male rats of prolonged administration of the experimental hepatocarcinogen nafenopin, a hypolipidemic agent and peroxisome proliferator, were compared to those of another experimental liver carcinogen, phenobarbital, which acts as a neoplasm promoter. Feeding of nafenopin, 0.03 mmol/kg basal diet for up to 24 weeks increased the numbers of hepatic peroxisomes, increased catalase activity, markedly decreased cytosolic glutathione transferase activities toward two substrates, decreased cytosolic glutathione peroxidase activities toward H2O2 and two organic peroxides, and suppressed the age-related increase in gamma-glutamyl transpeptidase activity. In contrast the livers of rats fed an equimolar concentration of phenobarbital displayed increases in cytosolic glutathione transferase activities and enhancement of gamma-glutamyl transpeptidase activity but no changes in glutathione peroxidase activities. There was also an enhancement of catalase activity without apparent increase in peroxisome number. Enzyme kinetic analyses revealed that the cytosolic glutathione transferase activities toward two halogenonitrobenzene substrates were inhibited in the rats fed nafenopin and displayed elevated Km and decreased Vmax. Kinetic studies of glutathione transferase activities in which nafenopin was mixed with normal rat liver cytosols in the assay system revealed competitive type inhibition toward 1-chloro-2,4-dinitrobenzene and a noncompetitive type of inhibition toward 3,4-dichloronitrobenzene. Likewise activities of glutathione peroxidases toward H2O2 and cumene hydroperoxide were suppressed by in vitro addition. Thus the effects of nafenopin and phenobarbital on liver biochemistry were very different. The inhibition of hepatic biotransformation and scavenger systems by nafenopin is suggested to be relevant to its hepatocarcinogenicity.

  12. Transition to Accrual Accounting in the Public Sector of Developed and Developing Countries : Problems and Requirements. With Special Focus on the Netherlands and Egypt

    NARCIS (Netherlands)

    Ouda, H.A.G.

    2005-01-01

    The purpose of this study is to develop a better understanding of the way in which accrual accounting can successfully be adopted in the public sector as well as to attain the target benefits of that adoption. This study investigates both theoretically and empirically the transition problems that

  13. Anorexia‐cachexia syndrome in hepatoma tumour‐bearing rats requires the area postrema but not vagal afferents and is paralleled by increased MIC‐1/GDF15

    Science.gov (United States)

    Borner, Tito; Arnold, Myrtha; Ruud, Johan; Breit, Samuel N.; Langhans, Wolfgang; Lutz, Thomas A.; Blomqvist, Anders

    2016-01-01

    Abstract Background The cancer‐anorexia‐cachexia syndrome (CACS) negatively affects survival and therapy success in cancer patients. Inflammatory mediators and tumour‐derived factors are thought to play an important role in the aetiology of CACS. However, the central and peripheral mechanisms contributing to CACS are insufficiently understood. The area postrema (AP) and the nucleus tractus solitarii are two important brainstem centres for the control of eating during acute sickness conditions. Recently, the tumour‐derived macrophage inhibitory cytokine‐1 (MIC‐1) emerged as a possible mediator of cancer anorexia because lesions of these brainstem areas attenuated the anorectic effect of exogenous MIC‐1 in mice. Methods Using a rat hepatoma tumour model, we examined the roles of the AP and of vagal afferents in the mediation of CACS. Specifically, we investigated whether a lesion of the AP (APX) or subdiaphragmatic vagal deafferentation (SDA) attenuate anorexia, body weight, muscle, and fat loss. Moreover, we analysed MIC‐1 levels in this tumour model and their correlation with tumour size and the severity of the anorectic response. Results In tumour‐bearing sham‐operated animals mean daily food intake significantly decreased. The anorectic response was paralleled by a significant loss of body weight and muscle mass. APX rats were protected against anorexia, body weight loss, and muscle atrophy after tumour induction. In contrast, subdiaphragmatic vagal deafferentation did not attenuate cancer‐induced anorexia or body weight loss. Tumour‐bearing rats had substantially increased MIC‐1 levels, which positively correlated with tumour size and cancer progression and negatively correlated with food intake. Conclusions These findings demonstrate the importance of the AP in the mediation of cancer‐dependent anorexia and body weight loss and support a pathological role of MIC‐1 as a tumour‐derived factor mediating CACS, possibly via an AP

  14. Anorexia-cachexia syndrome in hepatoma tumour-bearing rats requires the area postrema but not vagal afferents and is paralleled by increased MIC-1/GDF15.

    Science.gov (United States)

    Borner, Tito; Arnold, Myrtha; Ruud, Johan; Breit, Samuel N; Langhans, Wolfgang; Lutz, Thomas A; Blomqvist, Anders; Riediger, Thomas

    2017-06-01

    The cancer-anorexia-cachexia syndrome (CACS) negatively affects survival and therapy success in cancer patients. Inflammatory mediators and tumour-derived factors are thought to play an important role in the aetiology of CACS. However, the central and peripheral mechanisms contributing to CACS are insufficiently understood. The area postrema (AP) and the nucleus tractus solitarii are two important brainstem centres for the control of eating during acute sickness conditions. Recently, the tumour-derived macrophage inhibitory cytokine-1 (MIC-1) emerged as a possible mediator of cancer anorexia because lesions of these brainstem areas attenuated the anorectic effect of exogenous MIC-1 in mice. Using a rat hepatoma tumour model, we examined the roles of the AP and of vagal afferents in the mediation of CACS. Specifically, we investigated whether a lesion of the AP (APX) or subdiaphragmatic vagal deafferentation (SDA) attenuate anorexia, body weight, muscle, and fat loss. Moreover, we analysed MIC-1 levels in this tumour model and their correlation with tumour size and the severity of the anorectic response. In tumour-bearing sham-operated animals mean daily food intake significantly decreased. The anorectic response was paralleled by a significant loss of body weight and muscle mass. APX rats were protected against anorexia, body weight loss, and muscle atrophy after tumour induction. In contrast, subdiaphragmatic vagal deafferentation did not attenuate cancer-induced anorexia or body weight loss. Tumour-bearing rats had substantially increased MIC-1 levels, which positively correlated with tumour size and cancer progression and negatively correlated with food intake. These findings demonstrate the importance of the AP in the mediation of cancer-dependent anorexia and body weight loss and support a pathological role of MIC-1 as a tumour-derived factor mediating CACS, possibly via an AP-dependent action. © 2016 The Authors. Journal of Cachexia, Sarcopenia and Muscle

  15. Writing testable software requirements

    Energy Technology Data Exchange (ETDEWEB)

    Knirk, D. [Sandia National Labs., Albuquerque, NM (United States)

    1997-11-01

    This tutorial identifies common problems in analyzing requirements in the problem and constructing a written specification of what the software is to do. It deals with two main problem areas: identifying and describing problem requirements, and analyzing and describing behavior specifications.

  16. Class and Home Problems: Optimization Problems

    Science.gov (United States)

    Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard

    2011-01-01

    Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…

  17. The LuxS/AI-2 Quorum-Sensing System of Streptococcus pneumoniae Is Required to Cause Disease, and to Regulate Virulence- and Metabolism-Related Genes in a Rat Model of Middle Ear Infection

    Directory of Open Access Journals (Sweden)

    Mukesh K. Yadav

    2018-05-01

    Full Text Available Objective:Streptococcus pneumoniae colonizes the nasopharynx of children, and from nasopharynx it could migrate to the middle ear and causes acute otitis media (AOM. During colonization and AOM, the pneumococcus forms biofilms. In vitro biofilm formation requires a functional LuxS/AI-2 quorum-sensing system. We investigated the role of LuxS/AI-2 signaling in pneumococcal middle ear infection, and identified the genes that are regulated by LuxS/AI-2 during pneumococcal biofilm formation.Methods:Streptococcus pneumoniae D39 wild-type and an isogenic D39ΔluxS strain were utilized to evaluate in vitro biofilm formation, and in vivo colonization and epithelial damage using a microtiter plate assay and a rat model of pneumococcal middle ear infection, respectively. Biofilm structures and colonization and epithelial damage were evaluated at the ultrastructural level by scanning electron microscopy and confocal microscopy. Microarrays were used to investigate the global genes that were regulated by LuxS/AI-2 during biofilm formation.Results: The biofilm biomass and density of D39ΔluxS were significantly (p < 0.05 lower than those of D39 wild-type. SEM and confocal microscopy revealed that D39ΔluxS formed thin biofilms in vitro compared with D39 wild-type. The in vivo model of middle ear infection showed that D39ΔluxS resulted in ~60% less (p < 0.05 bacterial colonization than the wild-type. SEM analysis of the rat middle ears revealed dense biofilm-like cell debris deposited on the cilia in wild-type D39-infected rats. However, little cell debris was deposited in the middle ears of the D39ΔluxS-inoculated rats, and the cilia were visible. cDNA-microarray analysis revealed 117 differentially expressed genes in D39ΔluxS compared with D39 wild-type. Among the 66 genes encoding putative proteins and previously characterized proteins, 60 were significantly downregulated, whereas 6 were upregulated. Functional annotation revealed that genes involved in

  18. The Emergence of Extensively Drug‐Resistant Tuberculosis: A Global Health Crisis Requiring New Interventions: Part I: The Origins and Nature of the Problem

    OpenAIRE

    Ellner, Jerrold J.

    2008-01-01

    Surveillance studies and outbreak investigations indicate that an extensively drug‐resistant (XDR) form of tuberculosis (TB) is increasing in prevalence worldwide. In outbreak settings among HIV‐infected, there is a high‐case fatality rate. Better outcomes occur in HIV‐uninfected, particularly if drug susceptibility test (DST) results are available rapidly to allow tailoring of drug therapy. This review will be presented in two segments. The first characterizes the problem posed by XDR‐TB, ad...

  19. Caveolin 3-mediated integrin β1 signaling is required for the proliferation of folliculostellate cells in rat anterior pituitary gland under the influence of extracellular matrix.

    Science.gov (United States)

    Horiguchi, Kotaro; Fujiwara, Ken; Ilmiawati, Cimi; Kikuchi, Motoshi; Tsukada, Takehiro; Kouki, Tom; Yashiro, Takashi

    2011-07-01

    Folliculostellate (FS) cells in the anterior pituitary gland are believed to have multifunctional properties. Using transgenic rats that express green fluorescent protein (GFP) specifically in FS cells in the anterior pituitary gland (S100b-GFP rats), we recently revealed that FS cells in primary culture exhibited marked proliferation in the presence of laminin, an extracellular matrix (ECM) component of the basement membrane. In a process referred to as matricrine action, FS cells receive ECM as a signal through their receptors, which results in morphological and functional changes. In this study, we investigated matricrine signaling in FS cells and observed that the proliferation of FS cells is mediated by integrin β1, which is involved in various signaling pathways for cell migration and proliferation in response to ECM. Then, we analyzed downstream events of the integrin β1 signaling pathway in the proliferation of FS cells and identified caveolin 3 as a potential candidate molecule. Caveolin 3 is a membrane protein that binds cholesterol and a number of signaling molecules that interact with integrin β1. Using specific small interfering RNA of caveolin 3, the proliferation of FS cells was inhibited. Furthermore, caveolin 3 drove activation of the mitogen-activated protein kinase (MAPK) signaling cascades, which resulted in upregulation of cyclin D1 in FS cells. These findings suggest that matricrine signaling in the proliferation of FS cells was transduced by a caveolin 3-mediated integrin β1 signaling pathway and subsequent activation of the MAPK pathway. © 2011 Society for Endocrinology

  20. Research and Development for Health and Environmental Hazard Assessment -Task Order 2. Problem Definition of R and D Requirements for Field Sanitation and Water Supply.

    Science.gov (United States)

    1982-09-01

    34Development of a Kit for Hazardous Material Spills into Waterways," Edgewood Arsenal Special Publication ED- SP - 76023, 1976. Department of the Army...hepatitis, entamoeba hystolitica are more resistant and require free available chlorine residuals of 10 mg/l in cold weather and levels of 2, 5, 10

  1. Protective effect of DA-9401 in finasteride-induced apoptosis in rat testis: inositol requiring kinase 1 and c-Jun N-terminal kinase pathway

    Directory of Open Access Journals (Sweden)

    Soni KK

    2017-10-01

    Full Text Available Kiran Kumar Soni,1,* Yu Seob Shin,1,* Bo Ram Choi,1 Keshab Kumar Karna,1 Hye Kyung Kim,2 Sung Won Lee,3 Chul Young Kim,4 Jong Kwan Park1 1Department of Urology, Chonbuk National University and Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute and Clinical Trial Center of Medical Device of Chonbuk National University, Jeonju, 2College of Pharmacy, Kyungsung University, Busan, 3Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University Medical School, Seoul, 4College of Pharmacy, Hangyang University, Ansan, Republic of Korea *These authors contributed equally to this work Abstract: Finasteride is used to treat male pattern baldness and benign prostatic hyperplasia. This study investigated the toxicity of finasteride and recovery by DA-9401 using Sprague Dawley (SD rats. Forty adult male SD rats were assigned to four groups: control (CTR, finasteride 1 mg/kg/day (F, finasteride 1 mg/kg + DA-9401 100 mg/kg/day (F + DA 100 and finasteride 1 mg/kg + DA-9401 200 mg/kg/day (F + DA 200. Treatments were by oral delivery once daily for 90 consecutive days. The gross anatomical parameters assessed included: genital organ weight; vas deferens sperm count and sperm motility; testosterone, dihydrotestosterone (DHT and malondialdehyde levels; and histological and terminal deoxynucleotidyl transferase enzyme mediated dUTP nick-end labeling (TUNEL staining of testis for spermatogenic cell density, Johnsen’s score and apoptosis. Testicular tissue was also used for evaluating endoplasmic reticulum (ER stress and apoptotic proteins. Epididymis weight, seminal vesicle weight, prostate weight, penile weight and vas deferens sperm motility showed significant differences between the F group and the CTR, F + DA 100 and F + DA 200 groups. There was no significant change in the testosterone level. DHT level decreased significantly in the F group compared with the CTR

  2. Behaviour, stress and welfare of Sprague Dawley rats (Rattus norvegicus) on diet board feeding for 24 months

    DEFF Research Database (Denmark)

    Laaksonen, Sakari; Nevalainen, Timo; Ketola, Jukka

    2017-01-01

    .2% less than their AL counterparts. The DB rats of both sexes had 19% increased cage exploration during daytime and 20% reduced grooming during night-time compared to the AL rats. The increased FCMs may indicate slight stress in DB females. The EPM results indicate there was no anxiety due to DB feeding...... at six months. The cage behaviour could point to mild chronic stress in DB rats, but the lack of effect on escape-related behaviour and agonism suggests that there were no substantial welfare problems. DB feeding did not seem to disturb the circadian rhythm. The smaller food requirements of DB females...

  3. Decree of 2 July 1986 concerning the technical/scientific pluridisciplinary commission to study problems in certain fields requiring public protection measures

    International Nuclear Information System (INIS)

    1986-01-01

    This Decree of 2nd July 1986 (published in the Official Gazette of 29th July 1986) sets up a pluridisciplinary Commission which will advise the Minister for Protection of the Public in case of emergency situations in certain fields requiring public protection measures. The risks covered are the following: seismic, nuclear, volcanic, hydrological, chemical/industrial and ecological and finally, risks which may arise during transport. (NEA) [fr

  4. The emergence of extensively drug-resistant tuberculosis: a global health crisis requiring new interventions: part I: the origins and nature of the problem.

    Science.gov (United States)

    Ellner, Jerrold J

    2008-12-01

    Surveillance studies and outbreak investigations indicate that an extensively drug-resistant (XDR) form of tuberculosis (TB) is increasing in prevalence worldwide. In outbreak settings among HIV-infected, there is a high-case fatality rate. Better outcomes occur in HIV-uninfected, particularly if drug susceptibility test (DST) results are available rapidly to allow tailoring of drug therapy. This review will be presented in two segments. The first characterizes the problem posed by XDR-TB, addressing the epidemiology and evolution of XDR-TB and treatment outcomes. The second reviews technologic advances that may contribute to the solution, new diagnostics, and advances in understanding drug resistance and in the development of new drugs.

  5. Induction of Foxp3-expressing regulatory T-cells by donor blood transfusion is required for tolerance to rat liver allografts.

    Directory of Open Access Journals (Sweden)

    Yuta Abe

    Full Text Available BACKGROUND: Donor-specific blood transfusion (DST prior to solid organ transplantation has been shown to induce long-term allograft survival in the absence of immunosuppressive therapy. Although the mechanisms underlying DST-induced allograft tolerance are not well defined, there is evidence to suggest DST induces one or more populations of antigen-specific regulatory cells that suppress allograft rejection. However, neither the identity nor the regulatory properties of these tolerogenic lymphocytes have been reported. Therefore, the objective of this study was to define the kinetics, phenotype and suppressive function of the regulatory cells induced by DST alone or in combination with liver allograft transplantation (LTx. METHODOLOGY/PRINCIPAL FINDINGS: Tolerance to Dark Agouti (DA; RT1(a rat liver allografts was induced by injection (iv of 1 ml of heparinized DA blood to naïve Lewis (LEW; RT1(l rats once per week for 4 weeks prior to LTx. We found that preoperative DST alone generates CD4(+ T-cells that when transferred into naïve LEW recipients are capable of suppressing DA liver allograft rejection and promoting long-term survival of the graft and recipient. However, these DST-generated T-cells did not express the regulatory T-cell (Treg transcription factor Foxp3 nor did they suppress alloantigen (DA-induced activation of LEW T-cells in vitro suggesting that these lymphocytes are not fully functional regulatory Tregs. We did observe that DST+LTx (but not DST alone induced the time-dependent formation of CD4(+Foxp3(+ Tregs that potently suppressed alloantigen-induced activation of naïve LEW T-cells in vitro and liver allograft rejection in vivo. Finally, we present data demonstrating that virtually all of the Foxp3-expressing Tregs reside within the CD4(+CD45RC(- population whereas in which approximately 50% of these Tregs express CD25. CONCLUSIONS/SIGNIFICANCE: We conclude that preoperative DST, in the absence of liver allograft

  6. PTSD in post-road traffic accident patients requiring hospitalization in Indian subcontinent: A review on magnitude of the problem and management guidelines.

    Science.gov (United States)

    Undavalli, Chaitanya; Das, Piyush; Dutt, Taru; Bhoi, Sanjeev; Kashyap, Rahul

    2014-10-01

    Traumatic events after a road traffic accident (RTA) can be physical and/or psychological. Posttraumatic stress disorder (PTSD) is one of the major psychological conditions which affect accident victims. Psychological issues may not be addressed in the emergency department(ED) immediately. There have been reports about a mismatch between the timely referrals from ED to occupational or primary care services for these issues. If left untreated, there may be adverse effects on quality of life (QOL) and work productivity. Hospital expenses, loss of income, and loss of work could create a never ending cycle for financial difficulties and burden in trauma victims. The aim of our review is to address the magnitude of PTSD in post-RTA hospitalized patients in Indian subcontinent population. We also attempted to emphasis on few management guidelines. A comprehensive search was conducted on major databases with Medical Subject Headings (MeSH) term 'PTSD or post-traumatic stress' and Emergency department and vehicle or road or highway or automobile or car or truck or trauma and India. Out of 120 studies, a total of six studies met our inclusion criteria and were included in the review. Our interpretation of the problem is that; hospital expenditure due to trauma, time away from work during hospitalization, and reduction in work performance, are three major hits that can lead RTA victims to financial crisis. Proposed management guidelines are; establish a coordinated triage, implementing a screening tool in the ED, and provide psychological counseling.

  7. PTSD in post-road traffic accident patients requiring hospitalization in Indian subcontinent: A review on magnitude of the problem and management guidelines

    Directory of Open Access Journals (Sweden)

    Chaitanya Undavalli

    2014-01-01

    Full Text Available Traumatic events after a road traffic accident (RTA can be physical and/or psychological. Posttraumatic stress disorder (PTSD is one of the major psychological conditions which affect accident victims. Psychological issues may not be addressed in the emergency department(ED immediately. There have been reports about a mismatch between the timely referrals from ED to occupational or primary care services for these issues. If left untreated, there may be adverse effects on quality of life (QOL and work productivity. Hospital expenses, loss of income, and loss of work could create a never ending cycle for financial difficulties and burden in trauma victims. The aim of our review is to address the magnitude of PTSD in post-RTA hospitalized patients in Indian subcontinent population. We also attempted to emphasis on few management guidelines. A comprehensive search was conducted on major databases with Medical Subject Headings (MeSH term ′PTSD or post-traumatic stress′ and Emergency department and vehicle or road or highway or automobile or car or truck or trauma and India. Out of 120 studies, a total of six studies met our inclusion criteria and were included in the review. Our interpretation of the problem is that; hospital expenditure due to trauma, time away from work during hospitalization, and reduction in work performance, are three major hits that can lead RTA victims to financial crisis. Proposed management guidelines are; establish a coordinated triage, implementing a screening tool in the ED, and provide psychological counseling.

  8. Neurons of the A5 region are required for the tachycardia evoked by electrical stimulation of the hypothalamic defence area in anaesthetized rats.

    Science.gov (United States)

    López-González, M V; Díaz-Casares, A; Peinado-Aragonés, C A; Lara, J P; Barbancho, M A; Dawid-Milner, M S

    2013-08-01

    In order to assess the possible interactions between the pontine A5 region and the hypothalamic defence area (HDA), we have examined the pattern of double staining for c-Fos protein immunoreactivity (c-Fos-ir) and tyrosine hydroxylase, throughout the rostrocaudal extent of the A5 region in spontaneously breathing anaesthetized male Sprague-Dawley rats during electrical stimulation of the HDA. Activation of the HDA elicited a selective increase in c-Fos-ir with an ipsilateral predominance in catecholaminergic and non-catecholaminergic A5 somata (P HDA. Cardiorespiratory changes were analysed in response to electrical stimulation of the HDA before and after ipsilateral microinjection of muscimol within the A5 region. Stimulation of the HDA evoked an inspiratory facilitatory response, consisting of an increase in respiratory rate (P HDA stimulation were reduced (P HDA and the A5 region, extracellular recordings of putative A5 neurones were obtained during HDA stimulation. Seventy-five A5 cells were recorded, 35 of which were affected by the HDA (47%). These results indicate that neurones of the A5 region participate in the cardiovascular response evoked from the HDA. The possible mechanisms involved in these interactions are discussed.

  9. Is "disease management" the answer to our problems? No! Population health management and (disease) prevention require "management of overall well-being".

    Science.gov (United States)

    Cramm, Jane Murray; Nieboer, Anna Petra

    2016-09-21

    managing their own well-being and adequately addressing their needs in a broader sense. So, is disease management the answer to our problems in the time of aging populations and increased prevalence of unhealthy lifestyles, chronic illnesses, and comorbidity? No! Effective (disease) prevention, disease management, patient-centered care, and high-quality chronic care and/or population health management calls for management of overall well-being.

  10. Activation of Nrf2 is required for up-regulation of the π class of glutathione S-transferase in rat primary hepatocytes with L-methionine starvation.

    Science.gov (United States)

    Lin, Ai-Hsuan; Chen, Haw-Wen; Liu, Cheng-Tze; Tsai, Chia-Wen; Lii, Chong-Kuei

    2012-07-04

    Numerous genes expression is regulated in response to amino acid shortage, which helps organisms adapt to amino acid limitation. The expression of the π class of glutathione (GSH) S-transferase (GSTP), a highly inducible phase II detoxification enzyme, is regulated mainly by activates activating protein 1 (AP-1) binding to the enhancer I of GSTP (GPEI). Here we show the critical role of nuclear factor erythroid-2-related factor 2 (Nrf2) in up-regulating GSTP gene transcription. Primary rat hepatocytes were cultured in a methionine-restricted medium, and immunoblotting and RT-PCR analyses showed that methionine restriction time-dependently increased GSTP protein and mRNA expression over a 48 h period. Nrf2 translocation to the nucleus, nuclear proteins binding to GPEI, and antioxidant response element (ARE) luciferase reporter activity were increased by methionine restriction as well as by l-buthionine sulfoximine (BSO), a GSH synthesis inhibitor. Transfection with Nrf2 siRNA knocked down Nrf2 expression and reversed the methionine-induced GSTP expression and GPEI binding activity. Chromatin immunoprecipitation assay confirmed the binding of Nrf2 to the GPEI. Phosphorylation of extracellular signal-regulated kinase 2 (ERK2) was increased in methionine-restricted and BSO-treated cells. ERK2 siRNA abolished methionine restriction-induced Nrf2 nuclear translocation, GPEI binding activity, ARE-luciferase reporter activity, and GSTP expression. Our results suggest that the up-regulation of GSTP gene transcription in response to methionine restriction likely occurs via the ERK-Nrf2-GPEI signaling pathway.

  11. Balance Problems

    Science.gov (United States)

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

  12. Biochemical and Haematological Indices of Weanly Albino Rats Fed ...

    African Journals Online (AJOL)

    acer

    ABSTRACT: Malnutrition is a public health problem in Nigeria accounting for more than 50% of ... weanly albino rats using nutritional, biochemical ... groundnut (16%), soy beans (16%), crayfish ... consumption was observed in rats on PC and.

  13. Pollution problems plague Poland

    International Nuclear Information System (INIS)

    Bajsarowicz, J.F.

    1989-01-01

    Poland's environmental problems are said to stem from investments in heavy industries that require enormous quantities of power and from the exploitation of two key natural resources: coal and sulfur. Air and water pollution problems and related public health problems are discussed

  14. [Population problem, comprehension problem].

    Science.gov (United States)

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

  15. Speech Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Speech Problems KidsHealth / For Teens / Speech Problems What's in ... a person's ability to speak clearly. Some Common Speech and Language Disorders Stuttering is a problem that ...

  16. Closure requirements

    International Nuclear Information System (INIS)

    Hutchinson, I.P.G.; Ellison, R.D.

    1992-01-01

    Closure of a waste management unit can be either permanent or temporary. Permanent closure may be due to: economic factors which make it uneconomical to mine the remaining minerals; depletion of mineral resources; physical site constraints that preclude further mining and beneficiation; environmental, regulatory or other requirements that make it uneconomical to continue to develop the resources. Temporary closure can occur for a period of several months to several years, and may be caused by factors such as: periods of high rainfall or snowfall which prevent mining and waste disposal; economic circumstances which temporarily make it uneconomical to mine the target mineral; labor problems requiring a cessation of operations for a period of time; construction activities that are required to upgrade project components such as the process facilities and waste management units; and mine or process plant failures that require extensive repairs. Permanent closure of a mine waste management unit involves the provision of durable surface containment features to protect the waters of the State in the long-term. Temporary closure may involve activities that range from ongoing maintenance of the existing facilities to the installation of several permanent closure features in order to reduce ongoing maintenance. This paper deals with the permanent closure features

  17. Explaining the Mind: Problems, Problems

    OpenAIRE

    Harnad, Stevan

    2001-01-01

    The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

  18. Enuresis: A Social Problem.

    Science.gov (United States)

    McDonald, James E.

    1978-01-01

    Several theories and treatments of enuresis are described. The authors conclude that enuresis is a social problem (perhaps due to maturational lag, developmental delay or faulty learning) which requires teacher and parental tolerance and understanding. (SE)

  19. Problems in baryon spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Capstick, S. [Florida State Univ., Tallahassee, FL (United States)

    1994-04-01

    Current issues and problems in the physics of ground- and excited-state baryons are considered, and are classified into those which should be resolved by CEBAF in its present form, and those which may require CEBAF to undergo an energy upgrade to 8 GeV or more. Recent theoretical developments designed to address these problems are outlined.

  20. Prostate Problems

    Science.gov (United States)

    ... know the exact cause of your prostate problem. Prostatitis The cause of prostatitis depends on whether you ... prostate problem in men older than age 50. Prostatitis If you have a UTI, you may be ...

  1. General problems

    International Nuclear Information System (INIS)

    2005-01-01

    This article presents the general problems as natural disasters, consequences of global climate change, public health, the danger of criminal actions, the availability to information about problems of environment

  2. Learning Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Learning Problems KidsHealth / For Kids / Learning Problems What's in ... for how to make it better. What Are Learning Disabilities? Learning disabilities aren't contagious, but they ...

  3. Ankle Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Ankle ProblemsFollow this chart for more information about problems that can cause ankle pain. Our trusted Symptom Checker is written and ...

  4. U(1) problem

    Energy Technology Data Exchange (ETDEWEB)

    McDougall, N.A. (Oxford Univ. (UK). Dept. of Theoretical Physics)

    1984-08-23

    The resolution of the U(1) problem requires the quark condensates to have a specific THETA dependence. We show that the required THETA dependence arises naturally upon application of the index theorem during the calculation of the dynamically generated quark mass.

  5. Problems in equilibrium theory

    CERN Document Server

    Aliprantis, Charalambos D

    1996-01-01

    In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

  6. Sociale problemer

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter Verner

    Sociale problemer kan betragtes som selve udgangspunktet for socialt arbejde, hvor ambitionen er at råde bod på problemerne og sikre, at udsatte borgere får en bedre tilværelse. Det betyder også, at diskussionen af sociale problemer er afgørende for den sociale grundfaglighed. I denne bog sætter en...... række fagfolk på tværs af det danske socialfaglige felt fokus på sociale problemer. Det diskuteres, hvad vi overhovedet forstår ved sociale problemer, hvordan de opstår, hvilke konsekvenser de har, og ikke mindst hvordan man som fagprofessionel håndterer sociale problemer i det daglige arbejde. Bogen er...... skrevet som lærebog til professionsuddannelser, hvor sociale problemer udgør en dimension, bl.a. socialrådgiver-, pædagog- og sygeplejerskeuddannelserne....

  7. Follicle-stimulating hormone receptor-mediated uptake of 45Ca2+ by cultured rat Sertoli cells does not require activation of cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding proteins or adenylate cyclase

    International Nuclear Information System (INIS)

    Grasso, P.; Reichert, L.E. Jr.

    1990-01-01

    We have previously reported that FSH stimulates flux of 45Ca2+ into cultured Sertoli cells from immature rats via voltage-sensitive and voltage-independent calcium channels. In the present study, we show that this effect of FSH does not require cholera toxin (CT)- or pertussis toxin (PT)-sensitive guanine nucleotide binding (G) protein or activation of adenylate cyclase (AC). Significant stimulation of 45Ca2+ influx was observed within 1 min, and maximal response (3.2-fold over basal levels) was achieved within 2 min after exposure to FSH. FSH-stimulated elevations in cellular cAMP paralleled increases in 45Ca2+ uptake, suggesting a possible coupling of AC activation to 45Ca2+ influx. (Bu)2cAMP, however, was not able to enhance 45Ca2+ uptake over basal levels at a final concentration of 1000 microM, although a concentration-related increase in androstenedione conversion to estradiol was evident. Exposure of Sertoli cells to CT (10 ng/ml) consistently stimulated basal levels of androstenedione conversion to estradiol but had no effect on basal levels of 45Ca2+ uptake. Similarly, CT had no effect on FSH-induced 45Ca2+ uptake, but potentiated FSH-stimulated estradiol synthesis. PT (10 ng/ml) augmented basal and FSH-stimulated estradiol secretion without affecting 45Ca2+ influx. The adenosine analog N6-phenylisopropyladenosine, which binds to Gi-coupled adenosine receptors on Sertoli cells, inhibited FSH-stimulated androgen conversion to estradiol in a dose-related (1-1000 nM) manner, but FSH-stimulated 45Ca2+ influx remained unchanged. Our results show that in contrast to FSH-stimulated estradiol synthesis, the flux of 45Ca2+ into Sertoli cells in response to FSH is not mediated either directly or indirectly by CT- or PT-sensitive G protein, nor does it require activation of AC. Our data further suggest that the FSH receptor itself may function as a calcium channel

  8. Follicle-stimulating hormone receptor-mediated uptake of sup 45 Ca sup 2+ by cultured rat Sertoli cells does not require activation of cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding proteins or adenylate cyclase

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, P.; Reichert, L.E. Jr. (Albany Medical College, NY (USA))

    1990-08-01

    We have previously reported that FSH stimulates flux of 45Ca2+ into cultured Sertoli cells from immature rats via voltage-sensitive and voltage-independent calcium channels. In the present study, we show that this effect of FSH does not require cholera toxin (CT)- or pertussis toxin (PT)-sensitive guanine nucleotide binding (G) protein or activation of adenylate cyclase (AC). Significant stimulation of 45Ca2+ influx was observed within 1 min, and maximal response (3.2-fold over basal levels) was achieved within 2 min after exposure to FSH. FSH-stimulated elevations in cellular cAMP paralleled increases in 45Ca2+ uptake, suggesting a possible coupling of AC activation to 45Ca2+ influx. (Bu)2cAMP, however, was not able to enhance 45Ca2+ uptake over basal levels at a final concentration of 1000 microM, although a concentration-related increase in androstenedione conversion to estradiol was evident. Exposure of Sertoli cells to CT (10 ng/ml) consistently stimulated basal levels of androstenedione conversion to estradiol but had no effect on basal levels of 45Ca2+ uptake. Similarly, CT had no effect on FSH-induced 45Ca2+ uptake, but potentiated FSH-stimulated estradiol synthesis. PT (10 ng/ml) augmented basal and FSH-stimulated estradiol secretion without affecting 45Ca2+ influx. The adenosine analog N6-phenylisopropyladenosine, which binds to Gi-coupled adenosine receptors on Sertoli cells, inhibited FSH-stimulated androgen conversion to estradiol in a dose-related (1-1000 nM) manner, but FSH-stimulated 45Ca2+ influx remained unchanged. Our results show that in contrast to FSH-stimulated estradiol synthesis, the flux of 45Ca2+ into Sertoli cells in response to FSH is not mediated either directly or indirectly by CT- or PT-sensitive G protein, nor does it require activation of AC. Our data further suggest that the FSH receptor itself may function as a calcium channel.

  9. Hearing Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Hearing ProblemsLoss in the ability to hear or discriminate ... This flow chart will help direct you if hearing loss is a problem for you or a ...

  10. Problem Posing

    OpenAIRE

    Šilhavá, Marie

    2009-01-01

    This diploma thesis concentrates on problem posing from the students' point of view. Problem posing can be either seen as a teaching method which can be used in the class, or it can be used as a tool for researchers or teachers to assess the level of students' understanding of the topic. In my research, I compare three classes, one mathematics specialist class and two generalist classes, in their ability of problem posing. As an assessment tool it seemed that mathemathics specialists were abl...

  11. Effects of environmental enrichment on self-administration of the short-acting opioid remifentanil in male rats.

    Science.gov (United States)

    Hofford, Rebecca S; Chow, Jonathan J; Beckmann, Joshua S; Bardo, Michael T

    2017-12-01

    Opioid abuse is a major problem around the world. Identifying environmental factors that contribute to opioid abuse and addiction is necessary for decreasing this epidemic. In rodents, environmental enrichment protects against the development of low dose stimulant self-administration, but studies examining the effect of enrichment and isolation (compared to standard housing) on the development of intravenous opioid self-administration have not been conducted. The present study investigated the role of environmental enrichment on self-administration of the short-acting μ-opioid remifentanil. Rats were raised in an enriched condition (Enr), standard condition (Std), or isolated condition (Iso) beginning at 21 days of age and were trained to lever press for 1 or 3 μg/kg/infusion remifentanil in young adulthood. Acquisition of self-administration and responding during increasing fixed ratio requirements were assessed, and a dose-response curve was generated. In all phases, Enr rats lever pressed significantly less than Std and Iso rats, with Enr rats pressing between 9 and 40% the amount of Iso rats. Enr rats did not acquire remifentanil self-administration when trained with 1 μg/kg/infusion, did not increase responding over increasing FR when trained at either dose, and their dose-response curves were flattened compared to Std and Iso rats. When expressed as economic demand curves, Enr rats displayed a decrease in both essential value (higher α) and reinforcer intensity (Q 0 ) compared to Std and Iso rats at the 1 μg/kg/infusion training dose. Environmental enrichment reduced remifentanil intake, suggesting that social and environmental novelty may protect against opioid abuse.

  12. Problems in fluid flow

    International Nuclear Information System (INIS)

    Brasch, D.J.

    1986-01-01

    Chemical and mineral engineering students require texts which give guidance to problem solving to complement their main theoretical texts. This book has a broad coverage of the fluid flow problems which these students may encounter. The fundamental concepts and the application of the behaviour of liquids and gases in unit operation are dealt with. The book is intended to give numerical practice; development of theory is undertaken only when elaboration of treatments available in theoretical texts is absolutely necessary

  13. Popular Problems

    DEFF Research Database (Denmark)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....

  14. Sleep Problems

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... 101 KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  15. Mouth Problems

    Science.gov (United States)

    ... such as sores, are very common. Follow this chart for more information about mouth problems in adults. ... cancers. See your dentist if sharp or rough teeth or dental work are causing irritation. Start OverDiagnosisThis ...

  16. Kidney Problems

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & Information The kidneys are two ... kidney (renal) diseases are called nephrologists . What are Kidney Diseases? For about one-third of older people, ...

  17. Knapsack problems

    CERN Document Server

    Kellerer, Hans; Pisinger, David

    2004-01-01

    Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num­ ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...

  18. Problem Solving and Learning

    Science.gov (United States)

    Singh, Chandralekha

    2009-07-01

    One finding of cognitive research is that people do not automatically acquire usable knowledge by spending lots of time on task. Because students' knowledge hierarchy is more fragmented, "knowledge chunks" are smaller than those of experts. The limited capacity of short term memory makes the cognitive load high during problem solving tasks, leaving few cognitive resources available for meta-cognition. The abstract nature of the laws of physics and the chain of reasoning required to draw meaningful inferences makes these issues critical. In order to help students, it is crucial to consider the difficulty of a problem from the perspective of students. We are developing and evaluating interactive problem-solving tutorials to help students in the introductory physics courses learn effective problem-solving strategies while solidifying physics concepts. The self-paced tutorials can provide guidance and support for a variety of problem solving techniques, and opportunity for knowledge and skill acquisition.

  19. The academic rat race

    DEFF Research Database (Denmark)

    Landes, Xavier; Andersen, Martin Marchman; Nielsen, Morten Ebbe Juul

    2012-01-01

    : an increased pressure to produce articles (in peer-reviewed journals) has created an unbalanced emphasis on the research criterion at the expense of the latter two. More fatally, this pressure has turned academia into a rat race, leading to a deep change in the fundamental structure of academic behaviour......, and entailing a self-defeating and hence counter-productive pattern, where more publications is always better and where it becomes increasingly difficult for researchers to keep up with the new research in their field. The article identifies the pressure to publish as a problem of collective action. It ends up...

  20. treated rats

    African Journals Online (AJOL)

    aghomotsegin

    2014-01-08

    Jan 8, 2014 ... nucleus, bizarre segmentation; (I) shows hypersegmentation, bizarre segmentation of neutrophils in the shape of ring nucleus with polychromatophilic RBCs. 1998; Muller and Tobin, 1980). The current study shows that rats administered C. edulis hydro-ethanol extract, orally for 28 days, developed anemia, ...

  1. Calculus problems

    CERN Document Server

    Baronti, Marco; van der Putten, Robertus; Venturi, Irene

    2016-01-01

    This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...

  2. Thyroid Problems

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Thyroid Problems Font size A A A Print Share Glossary Basic ... enough thyroid hormone, usually of the thyroxine (T4) type of hormone. Your T4 levels can drop temporarily ...

  3. Balance Problems

    Science.gov (United States)

    ... fully trust your sense of balance. Loss of balance also raises the risk of falls. This is a serious and even life-threatening ... 65. Balance disorders are serious because of the risk of falls. But occasionally balance problems may warn of another health condition, such ...

  4. Atomic policies: history, problems

    International Nuclear Information System (INIS)

    Galvan, Cesare Giuseppe.

    1993-01-01

    Two kinds of problems follow from the development of nuclear technology: its use in (diversion to) armaments, and its dangers for the population. Both arise as social phenomena: technology can be diverted to military aims; and installations require specific measures in order not to expose human life to danger. The diffusion of this technology required a series of tentative solutions for such problems. Its history constitutes our first part. The second part aims at understanding the dynamics, which led to the diffusion of such a technology in the capitalist world. The concept of subsumption (especially of its realization) is suited to interpret the meanings of the social interests, which led content ro this diffusion. Subsumption is found between labor and capital, but also between society and state. At both levels, it shows that there was some social meaning in the diffusion of nuclear technology notwithstanding its problems. 590 refs

  5. Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system

    OpenAIRE

    Tsuruta James K; Dayton Paul A; Gallippi Caterina M; O'Rand Michael G; Streicker Michael A; Gessner Ryan C; Gregory Thomas S; Silva Erick JR; Hamil Katherine G; Moser Glenda J; Sokal David C

    2012-01-01

    Abstract Background Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive. Methods Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration ...

  6. Simian virus 40 small t antigen is not required for the maintenance of transformation but may act as a promoter (cocarcinogen) during establishment of transformation in resting rat cells.

    Science.gov (United States)

    Seif, R; Martin, R G

    1979-12-01

    Simian virus 40 deletion mutants affecting the 20,000-dalton (20K) t antigen and tsA mutants rendering the 90K T antigen temperature sensitive, as well as double mutants containing both mutations, induced host DNA synthesis in resting rat cells at the restrictive temperature. Nonetheless, the deletion mutants and double mutants did not induce transformation in resting cells even at the permissive temperature. On the other hand, the deletion mutants did induce full transformants when actively growing rat cells were infected; the transformants grew efficiently in agar and to high saturation densities on platic. The double mutants did not induce T-antigen-independent (temperature-insensitive) transformants which were shown previously to arise preferentially from resting cells. Thus, small t antigen was dispensable for the maintenance of the transformed phenotype in T-antigen-dependent rat transformants (transformants derived from growing cells) and may play a role in the establishment of T-antigen-independent transformants. We attempt to establish a parallel between transformation induced by chemical carcinogens and simian virus 40-induced transformation.

  7. Automatic Training of Rat Cyborgs for Navigation.

    Science.gov (United States)

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs.

  8. Upregulation of neuronal zinc finger protein A20 expression is required for electroacupuncture to attenuate the cerebral inflammatory injury mediated by the nuclear factor-kB signaling pathway in cerebral ischemia/reperfusion rats.

    Science.gov (United States)

    Zhan, Jian; Qin, Wenyi; Zhang, Ying; Jiang, Jing; Ma, Hongmei; Li, Qiongli; Luo, Yong

    2016-10-03

    Zinc finger protein A20 (tumor necrosis factor alpha-induced protein 3) functions as a potent negative feedback inhibitor of the nuclear factor-kB (NF-kB) signaling. It exerts these effects by interrupting the activation of IkB kinase beta (IKKβ), the most critical kinase in upstream of NF-kB, and thereby controlling inflammatory homeostasis. We reported previously that electroacupuncture (EA) could effectively suppress IKKβ activation. However, the mechanism underlying these effects was unclear. Therefore, the current study further explored the effects of EA on A20 expression in rat brain and investigated the possible mechanism of A20 in anti-neuroinflammation mediated by EA using transient middle cerebral artery occlusion (MCAO) rats. Rats were treated with EA at the "Baihui (GV20)," "Hegu (L14)," and "Taichong (Liv3)" acupoints once a day starting 2 h after focal cerebral ischemia. The spatiotemporal expression of A20, neurobehavioral scores, infarction volumes, cytokine levels, glial cell activation, and the NF-kB signaling were assessed at the indicated time points. A20 gene interference (overexpression and silencing) was used to investigate the role of A20 in mediating the neuroprotective effects of EA and in regulating the interaction between neuronal and glial cells by suppressing neuronal NF-kB signaling during cerebral ischemia/reperfusion-induced neuroinflammation. EA treatment increased A20 expression with an earlier peak and longer lasting upregulation. The upregulated A20 protein was predominantly located in neurons in the cortical zone of the ischemia/reperfusion. Furthermore, neuronal A20 cell counts were positively correlated with neurobehavioral scores but negatively correlated with infarct volume, the accumulation of pro-inflammatory cytokines, and glial cell activation. Moreover, the effects of EA on improving the neurological outcome and suppressing neuroinflammation in the brain were reversed by A20 silencing. Finally, A20 silencing also

  9. Complementarity problems

    CERN Document Server

    Isac, George

    1992-01-01

    The study of complementarity problems is now an interesting mathematical subject with many applications in optimization, game theory, stochastic optimal control, engineering, economics etc. This subject has deep relations with important domains of fundamental mathematics such as fixed point theory, ordered spaces, nonlinear analysis, topological degree, the study of variational inequalities and also with mathematical modeling and numerical analysis. Researchers and graduate students interested in mathematical modeling or nonlinear analysis will find here interesting and fascinating results.

  10. Agricultural problems

    International Nuclear Information System (INIS)

    Bickerton, George E.

    1997-01-01

    Although there were not reasons to deplore against major activity release from any of the 110 industrial reactors authorized to operate in US, the nuclear incident that occurred at the Three Mile Island Plant in 1979 urged the public conscience toward the necessity of readiness to cope with events of this type. The personnel of the Emergency Planning Office functioning in the frame of US Department of Agriculture has already participated in around 600 intervention drillings on a federal, local or state scale to plan, test or asses radiological emergency plans or to intervene locally. These exercises allowed acquiring a significant experience in elaborating emergency plans, planning the drillings, working out scenarios and evaluation of the potential impact of accidents from the agricultural point of view. We have also taken part in different international drillings among which the most recent are INEX 1 and RADEX 94. We have found on these occasions that the agricultural problems are essential preoccupations in most of the cases no matter if the context is international, national, local or of state level. The paper poses problems specifically related to milk, fruits and vegetables, soils, meat and meat products. Finally the paper discusses issues like drilling planning, alarm and notification, sampling strategy, access authorizations for farmers, removing of contamination wastes. A number of social, political and economical relating problems are also mentioned

  11. Matrices in Engineering Problems

    CERN Document Server

    Tobias, Marvin

    2011-01-01

    This book is intended as an undergraduate text introducing matrix methods as they relate to engineering problems. It begins with the fundamentals of mathematics of matrices and determinants. Matrix inversion is discussed, with an introduction of the well known reduction methods. Equation sets are viewed as vector transformations, and the conditions of their solvability are explored. Orthogonal matrices are introduced with examples showing application to many problems requiring three dimensional thinking. The angular velocity matrix is shown to emerge from the differentiation of the 3-D orthogo

  12. Heat transmission systems for heating and potable water. New requirements and problem solutions for hygiene, safety and improved heat utilization. Waermeuebertragungssysteme fuer Heizung und Trinkwasser. Neue Anforderungen und Problemloesungen bezueglich Hygiene, Sicherheit und besserer Waermenutzung

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, R

    1989-10-01

    In the past, additional demands were made on heat transmission systems regarding hygienic requirements in potable water heating plant for hospitals, hotels, sanatoriums and old-age homes, safety requirements to protect the potable water from the penetration of hazardous substances and requirements for improved heat utilization through return flow cooling and condensate cooling in the district heating. Where potable water heaters are concerned, safety radiators for heat transfer which comply with the requirements of DIN 1988 Part 2 and Part 4, as well as water heaters with permanent disinfection which are legionnaires' disease-proof, are now available for use in hospitals, old age homes and sanatoriums. For the district heating sector, improved range systems with low concentration in the hot water sector as well as condensate heat utilizing systems have been further developed in the steam heating sector. (orig.).

  13. Heart dysfunction and fibrosis in rat treated with myocardial ...

    African Journals Online (AJOL)

    Because cardiovascular disease remains a serious problem in modern human society, the aim of this study was to establish the rat model animal and to compare the heart dysfunction and fibrosis with SD and LE rats when treated with myocardial ischemia and reperfusion operation. A 20-minute thoracotomy was performed ...

  14. Kyrgyzstan's security problems today

    OpenAIRE

    Abduvalieva, Ryskul

    2009-01-01

    Regional stability and security consist of two levels-the external security of each country at the regional level and the internal security of each of them individually. A state's external and internal security are closely interrelated concepts. It stands to reason that ensuring internal security and stability is the primary and most important task. But the external aspect also requires attention. This article takes a look at the most important problems of ensuring Kyrgyzstan's security.

  15. Where have I been? Where should I go? Spatial working memory on a radial arm maze in a rat model of depression.

    Directory of Open Access Journals (Sweden)

    Sophie Helene Richter

    Full Text Available Disturbances in cognitive functioning are among the most debilitating problems experienced by patients with major depression. Investigations of these deficits in animals help to extend and refine our understanding of human emotional disorder, while at the same time providing valid tools to study higher executive functions in animals. We employ the "learned helplessness" genetic rat model of depression in studying working memory using an eight arm radial maze procedure with temporal delay. This so-called delayed spatial win-shift task consists of three phases, training, delay and test, requiring rats to hold information on-line across a retention interval and making choices based on this information in the test phase. According to a 2×2 factorial design, working memory performance of thirty-one congenitally helpless (cLH and non-helpless (cNLH rats was tested on eighteen trials, additionally imposing two different delay durations, 30 s and 15 min, respectively. While not observing a general cognitive deficit in cLH rats, the delay length greatly influenced maze performance. Notably, performance was most impaired in cLH rats tested with the shorter 30 s delay, suggesting a stress-related disruption of attentional processes in rats that are more sensitive to stress. Our study provides direct animal homologues of clinically important measures in human research, and contributes to the non-invasive assessment of cognitive deficits associated with depression.

  16. Linoleic acid intake and vitamin E requirement

    NARCIS (Netherlands)

    Jager, F.C.

    1973-01-01

    In experiments with rats and Peking ducklings it has been investigated to what extent the linoleic acid content of the diet is of influence on the requirement of vitamin E. This requirement was determined by adding D-α-tocopheryl acetate in increasing doses to vitamin E-free diets and to determine

  17. Software requirements

    CERN Document Server

    Wiegers, Karl E

    2003-01-01

    Without formal, verifiable software requirements-and an effective system for managing them-the programs that developers think they've agreed to build often will not be the same products their customers are expecting. In SOFTWARE REQUIREMENTS, Second Edition, requirements engineering authority Karl Wiegers amplifies the best practices presented in his original award-winning text?now a mainstay for anyone participating in the software development process. In this book, you'll discover effective techniques for managing the requirements engineering process all the way through the development cy

  18. Cosmology problems

    International Nuclear Information System (INIS)

    Lukash, V.N.

    1983-01-01

    Information discussed at the 18th General Assembly of the International Astronomical Union and Symposium on ''Early Universe Evolution and Its Modern Structure'' on the problems of relic radiation, Hubble expansion, spatial structure and physics of the early Universe is presented. The spectrum of relic radioemission differs but slightly from the equilibrium one in the maximum range. In G. Smith (USA) opinion such difference may be caused by any radiosources radiating in the same wave range. The absence of unanimous opinion of astronomers on Hubble constant value is pointed out. G.Tam-man (Switzerland) estimates the Hubble constant 50+-7 km/s. J. Voculer (USA) gives a twice greater value. Such divergence is ca sed by various methods of determining distances up to remote galaxies and galaxy clusters. Many reports deal with large-scale Universe structure. For the first time considered are the processes which occurred in the epoch at times about 10 -35 c from the beginning of the Universe expansion. Such possibility is presented by the theory of ''great unification'' which permits to explain some fundamental properties of the Universe: spatial uniformity of isotropic expansion, existence of small primary density perturbations

  19. Interaction between age and perceptual similarity in olfactory discrimination learning in F344 rats: relationships with spatial learning

    Science.gov (United States)

    Yoder, Wendy M.; Gaynor, Leslie S.; Burke, Sara N.; Setlow, Barry; Smith, David W.; Bizon, Jennifer L.

    2017-01-01

    Emerging evidence suggests that aging is associated with a reduced ability to distinguish perceptually similar stimuli in one’s environment. As the ability to accurately perceive and encode sensory information is foundational for explicit memory, understanding the neurobiological underpinnings of discrimination impairments that emerge with advancing age could help elucidate the mechanisms of mnemonic decline. To this end, there is a need for preclinical approaches that robustly and reliably model age-associated perceptual discrimination deficits. Taking advantage of rodents’ exceptional olfactory abilities, the present study applied rigorous psychophysical techniques to the evaluation of discrimination learning in young and aged F344 rats. Aging did not influence odor detection thresholds or the ability to discriminate between perceptually distinct odorants. In contrast, aged rats were disproportionately impaired relative to young on problems that required discriminations between perceptually similar olfactory stimuli. Importantly, these disproportionate impairments in discrimination learning did not simply reflect a global learning impairment in aged rats, as they performed other types of difficult discriminations on par with young rats. Among aged rats, discrimination deficits were strongly associated with spatial learning deficits. These findings reveal a new, sensitive behavioral approach for elucidating the neural mechanisms of cognitive decline associated with normal aging. PMID:28259065

  20. Uncovering the secret lives of sewer rats (Rattus norvegicus): Movements, distribution and population dynamics revealed by a capture-mark-recapture study

    DEFF Research Database (Denmark)

    Heiberg, Ann-Charlotte; Sluydts, Vincent; Leirs, Herwig E.l.

    2012-01-01

    Context.: In many parts of the world, brown rats have colonised sewer systems and the rat populations in sewers are often thought to be a source of problems with rats on the surface. The management of sewer rat populations is usually performed with little, if any, knowledge of the dynamics and be...

  1. RatMap--rat genome tools and data.

    Science.gov (United States)

    Petersen, Greta; Johnson, Per; Andersson, Lars; Klinga-Levan, Karin; Gómez-Fabre, Pedro M; Ståhl, Fredrik

    2005-01-01

    The rat genome database RatMap (http://ratmap.org or http://ratmap.gen.gu.se) has been one of the main resources for rat genome information since 1994. The database is maintained by CMB-Genetics at Goteborg University in Sweden and provides information on rat genes, polymorphic rat DNA-markers and rat quantitative trait loci (QTLs), all curated at RatMap. The database is under the supervision of the Rat Gene and Nomenclature Committee (RGNC); thus much attention is paid to rat gene nomenclature. RatMap presents information on rat idiograms, karyotypes and provides a unified presentation of the rat genome sequence and integrated rat linkage maps. A set of tools is also available to facilitate the identification and characterization of rat QTLs, as well as the estimation of exon/intron number and sizes in individual rat genes. Furthermore, comparative gene maps of rat in regard to mouse and human are provided.

  2. The Steiner tree problem

    CERN Document Server

    Hwang, FK; Winter, P

    1992-01-01

    The Steiner problem asks for a shortest network which spans a given set of points. Minimum spanning networks have been well-studied when all connections are required to be between the given points. The novelty of the Steiner tree problem is that new auxiliary points can be introduced between the original points so that a spanning network of all the points will be shorter than otherwise possible. These new points are called Steiner points - locating them has proved problematic and research has diverged along many different avenues. This volume is devoted to the assimilation of the rich field of intriguing analyses and the consolidation of the fragments. A section has been given to each of the three major areas of interest which have emerged. The first concerns the Euclidean Steiner Problem, historically the original Steiner tree problem proposed by Jarník and Kössler in 1934. The second deals with the Steiner Problem in Networks, which was propounded independently by Hakimi and Levin and has enjoyed the most...

  3. Radiation-induced cancers in the rat, an experimental study

    International Nuclear Information System (INIS)

    Morin, M.; Lafuma, J.

    1990-01-01

    Radiation carcinogenesis at low doses raises a major radiological protection problem; we have attempted to deal with it through animal investigations involving over 3,000 rats. For various radiation types, dose-effect relationships as well as possible synergies with endogenous or exogenous chemical factors were studied. The chief problem being the possibility of extrapolation to man, a comparison was made between man and rat with the only human data available from radon inhalation in uranium miners [fr

  4. Radiation-induced cancers in the rat, an experimental study

    International Nuclear Information System (INIS)

    Morin, M.; Lafuma, J.

    1988-09-01

    Radiation carcinogenesis at low doses raises a major radiological protection problem; we have attempted to deal with it through animal investigations involving over 3,000 rats. For various radiation types, dose-effect relationships as well as possible synergies with endogenous or exogenous chemical factors were studied. The chief problem being the possibility of extrapolation to man, a comparison was made between man and rat with the only human data available from radon inhalation in uranium miners [fr

  5. Diagnostic interface problems on TFTR

    International Nuclear Information System (INIS)

    Goldfarb, S.

    1977-01-01

    Diagnostic equipment on TFTR has functional interfaces with many machine systems. Salient requirements include plasma access, environmental resistance to thermal, magnetic and radiation effects, automated data acquisition and controls, remote handling and personnel safety. Problems imposed by these requirements and the solutions being considered are described

  6. On the U(1) problem

    International Nuclear Information System (INIS)

    McDougall, N.A.

    1984-01-01

    The resolution of the U(1) problem requires the quark condensates to have a specific THETA dependence. We show that the required THETA dependence arises naturally upon application of the index theorem during the calculation of the dynamically generated quark mass. (orig.)

  7. The Rat Race

    CERN Multimedia

    Stephen Haywood

    Dear Muriel, Being an animal, you are probably more familiar with rats than most of us. Yet it seems to me that our Community (not just ATLAS) is stuck in a huge "rat race". I am somewhat mystified as to how we have got ourselves into this and I wonder whether you or your readers could explain this - I give my own observations below. In HEP and ATLAS specifically, we are all working long hours and we are all becoming exhausted. There are people at Point 1 who are working day and night, every day of the week; there are people writing software who send emails round the clock, including weekends. It is one thing to have bursts of activity which require us to put in some longer hours, but in ATLAS, the bursts last months or years. I have been on ATLAS 14 years and it has felt like one endless rush. Why do we do this? We are all highly motivated, we love our work and want to succeed individually and collectively. We are parts of various teams, and we do not want to let the side down. We worked hard at school an...

  8. Spent fuel transportation problems

    International Nuclear Information System (INIS)

    Kondrat'ev, A.N.; Kosarev, Yu.A.; Yulikov, E.A.

    1977-01-01

    In this paper, problems of transportation of nuclear spent fuel to reprocessing plants are discussed. The solutions proposed are directed toward the achievement of the transportation as economic and safe as possible. The increase of the nuclear power plants number in the USSR and the great distances between these plants and the reprocessing plants involve an intensification of the spent fuel transportation. Higher burnup and holdup time reduction cause the necessity of more bulky casks. In this connection, the economic problems become still more important. One of the ways of the problem solution is the development of rational and cheap cask designs. Also, the enforcement in the world of the environmental and personnel health protection requires to increase the transportation reliability and safety. The paper summarizes safe transportation rules with clarifying the following questions: the increase of the transport unit quantity of the spent fuel; rational shipment organization that minimizes vehicle turnover cycle duration; development of the reliable calculation methods to determine strength, thermal conditions and nuclear safety of transport packaging as applied to the vehicles of high capacity; maximum unification of vehicles, calculation methods and documents; and cask testing on models and in pilot scale on specific test rigs to assure that they meet the international safe fuel shipment rules. Besides, some considerations on the choice and use of structural materials for casks are given, and problems of manufacturing such casks from uranium and lead are considered, as well as problems of the development of fireproof shells, control instrumentation, vehicles decontamination, etc. All the problems are considered from the point of view of normal and accidental shipment conditions. Conclusions are presented [ru

  9. Management of waste from nuclear facilities as a regulatory problem. Requirements to be met by legislation under conditions of uncertainty. Die Entsorgung der Kernenergie als Regelungsproblem. Zu den Anforderungen an Gesetzgebung unter Ungewissheitsbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Ladeur, K.H.

    1989-07-01

    The author presents a brief review of the development of the nuclear waste management regime in the Atomic Energy Act, referring also to court decissions and the literature. The article analyses the constitutionality of the waste management regulations of section 9a and following sections, and of the provisions on reprocessing (section 7, sub-sec. (1)), primarily under the aspect of the principle of proviso of legality in general, reformulated by the theory of materiality, and in particular with regard to the requirement of 'backfitting' in order to improve the regulatory system for complex and especially technological matters. (orig./RST).

  10. Brain network reorganization differs in response to stress in rats genetically predisposed to depression and stress-resilient rats.

    Science.gov (United States)

    Gass, N; Becker, R; Schwarz, A J; Weber-Fahr, W; Clemm von Hohenberg, C; Vollmayr, B; Sartorius, A

    2016-12-06

    Treatment-resistant depression (TRD) remains a pressing clinical problem. Optimizing treatment requires better definition of the specificity of the involved brain circuits. The rat strain bred for negative cognitive state (NC) represents a genetic animal model of TRD with high face, construct and predictive validity. Vice versa, the positive cognitive state (PC) strain represents a stress-resilient phenotype. Although NC rats show depressive-like behavior, some symptoms such as anhedonia require an external trigger, i.e. a stressful event, which is similar to humans when stressful event induces a depressive episode in genetically predisposed individuals (gene-environment interaction). We aimed to distinguish neurobiological predisposition from the depressogenic pathology at the level of brain-network reorganization. For this purpose, resting-state functional magnetic resonance imaging time series were acquired at 9.4 Tesla scanner in NC (N=11) and PC (N=7) rats before and after stressful event. We used a graph theory analytical approach to calculate the brain-network global and local properties. There was no difference in the global characteristics between the strains. At the local level, the response in the risk strain was characterized with an increased internodal role and reduced local clustering and efficiency of the anterior cingulate cortex (ACC) and prelimbic cortex compared to the stress-resilient strain. We suggest that the increased internodal role of these prefrontal regions could be due to the enhancement of some of their long-range connections, given their connectivity with the amygdala and other default-mode-like network hubs, which could create a bias to attend to negative information characteristic for depression.

  11. Total parenteral nutrition in diabetic rats

    International Nuclear Information System (INIS)

    Norcross, E.D.; Stein, T.P.

    1986-01-01

    Parenteral Nutrition with hypertonic glucose is frequently given to diabetic patients. Large amounts of insulin can be required. The purpose of this investigation was to develop a totally parenterally nourished diabetic rat model. 200 g Female Sprague Dawley rats were made diabetic by i.v. injection of streptozotocin (50 mg/kg). Rats were then allowed to recover for at least 1 week before undergoing surgical insertion of a central venous catheter for parenteral feeding. TPN was begun 3 days after surgery. Prior to this they were allowed unlimited access to food and water. Control (non-streptozotocin treated) rats were run at the same time. Protein turnover was investigated by using 15 N glycine. Preliminary results: diabetic rats given mostly fat as a calorie source survived well in the absence of exogenous insulin whereas those that were given glucose only as their non-protein calorie source showed poor survival even with exogenous insulin. N balance and protein turnover in the lipid treated diabetic rats were comparable to the non-diabetic control rats

  12. Environmental enrichment improves learning and memory and long-term potentiation in young adult rats through a mechanism requiring mGluR5 signaling and sustained activation of p70s6k.

    Science.gov (United States)

    Hullinger, Rikki; O'Riordan, Kenneth; Burger, Corinna

    2015-11-01

    Previous studies from our lab have demonstrated that mild cognitive impairments identified early in life are predictive of cognitive deficits that develop with age, suggesting that enhancements in cognition at an early age can provide a buffer against age-related cognitive decline. Environmental enrichment has been shown to improve learning and memory in the rodent, but the impact of enrichment on synaptic plasticity and the molecular mechanisms behind enrichment are not completely understood. To address these unresolved issues, we have housed 2-month old rats in environmentally enriched (EE), socially enriched (SE), or standard housing (SC) and conducted tests of learning and memory formation at various time intervals. Here we demonstrate that animals that have been exposed to one month of social or environmental enrichment demonstrate enhanced learning and memory relative to standard housed controls. However, we have found that after 4months EE animals perform better than both SE and SC groups and demonstrate an enhanced hippocampal LTP. Our results demonstrate that this LTP is dependent on mGluR5 signaling, activation of ERK and mTOR signaling cascades, and sustained phosphorylation of p70s6 kinase, thus providing a potential target mechanism for future studies of cognitive enhancement in the rodent. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Rat Genome Database (RGD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Rat Genome Database (RGD) is a collaborative effort between leading research institutions involved in rat genetic and genomic research to collect, consolidate,...

  14. Fusion reactor problems

    International Nuclear Information System (INIS)

    Carruthers, R.

    It is pointed out that plasma parameters for a fusion reactor have been fairly accurately defined for many years, and the real plasma physics objective must be to find the means of achieving and maintaining these specifiable parameters. There is good understanding of the generic technological problems: breading blankets and shields, radiation damage, heat transfer and methods of magnet design. The required plasma parameters for fusion self-heated reactors are established at ntausub(E) approximately 2.10 14 cm -3 sec, plasma radius 1.5 to 3 m, wall loading 5 to 10 MW cm -2 , temperature 15 keV. Within this model plasma control by quasi-steady burn as a key problem is studied. It is emphasized that the future programme must interact more closely with engineering studies and should concentrate upon research which is relevant to reactor plasmas. (V.P.)

  15. 2-Sensor Problem

    Directory of Open Access Journals (Sweden)

    Michael Segal

    2004-11-01

    Full Text Available Abstract: Ad-hoc networks of sensor nodes are in general semi-permanently deployed. However, the topology of such networks continuously changes over time, due to the power of some sensors wearing out to new sensors being inserted into the network, or even due to designers moving sensors around during a network re-design phase (for example, in response to a change in the requirements of the network. In this paper, we address the problem of covering a given path by a limited number of sensors — in our case to two, and show its relation to the well-studied matrix multiplication problem.

  16. Routing and scheduling problems

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander

    couple of decades. To deliver competitive service and price, transportation today needs to be cost effective. A company requiring for things to be shipped will aim at having the freight shipped as cheaply as possible while often satisfying certain time constraints. For the transportation company......, the effectiveness of the network is of importance aiming at satisfying as many costumer demands as possible at a low cost. Routing represent a path between locations such as an origin and destination for the object routed. Sometimes routing has a time dimension as well as the physical paths. This may...... set cost making the cost of the individual vehicle routes inter-dependant. Depending on the problem type, the size of the problems and time available for solving, different solution methods can be applicable. In this thesis both heuristic methods and several exact methods are investigated depending...

  17. MCNP: Photon benchmark problems

    International Nuclear Information System (INIS)

    Whalen, D.J.; Hollowell, D.E.; Hendricks, J.S.

    1991-09-01

    The recent widespread, markedly increased use of radiation transport codes has produced greater user and institutional demand for assurance that such codes give correct results. Responding to these pressing requirements for code validation, the general purpose Monte Carlo transport code MCNP has been tested on six different photon problem families. MCNP was used to simulate these six sets numerically. Results for each were compared to the set's analytical or experimental data. MCNP successfully predicted the analytical or experimental results of all six families within the statistical uncertainty inherent in the Monte Carlo method. From this we conclude that MCNP can accurately model a broad spectrum of photon transport problems. 8 refs., 30 figs., 5 tabs

  18. Guest Comment: Universal Language Requirement.

    Science.gov (United States)

    Sherwood, Bruce Arne

    1979-01-01

    Explains that reading English among Scientists is almost universal, however, there are enormous problems with spoken English. Advocates the use of Esperanto as a viable alternative, and as a language requirement for graduate work. (GA)

  19. Successful ovarian autotransplant with no vascular reanastomosis in rats.

    Science.gov (United States)

    Barros, Flávio S V; de Oliveira, Rodrigo M; Alves, Felipe M T; Sampaio, Marcos; Geber, Selmo

    2008-12-15

    Preservation of ovarian functions in woman with premature ovarian failure remains an issue in reproductive medicine. Hormone replacement therapy for maintaining endocrine functions, and cryopreservation of embryos or oocytes for those who wish pregnancy, are some of the choices. However, ovarian transplantation is a more physiological alternative, although problems related to ovarian ischemia have been reported. Herein, we investigated the viability of autologous transplantation of the ovarian tissue into the rat peritoneum, without vascular reanastomosis. Twenty animals in the study group had both ovaries excised, and each ovary was dissected into two halves. A half of an ovary was autotransplanted to the peritoneal surface, closely located to the left epigastric vessels. This simple procedure does not require surgical vascular reanastomosis while it maintains appropriate follicular growth and therefore should be further considered as an alternative for women undergoing oophorectomy, not only to maintain endocrine functions but also for fertility preservation.

  20. Precise control of miR-125b levels is required to create a regeneration-permissive environment after spinal cord injury: a cross-species comparison between salamander and rat

    Directory of Open Access Journals (Sweden)

    Juan Felipe Diaz Quiroz

    2014-06-01

    Full Text Available Most spinal cord injuries lead to permanent paralysis in mammals. By contrast, the remarkable regenerative abilities of salamanders enable full functional recovery even from complete spinal cord transections. The molecular differences underlying this evolutionary divergence between mammals and amphibians are poorly understood. We focused on upstream regulators of gene expression as primary entry points into this question. We identified a group of microRNAs (miRNAs that are conserved between the Mexican axolotl salamander (Ambystoma mexicanum and mammals but show marked cross-species differences in regulation patterns following spinal cord injury. We found that precise post-injury levels of one of these miRNAs (miR-125b is essential for functional recovery, and guides correct regeneration of axons through the lesion site in a process involving the direct downstream target Sema4D in axolotls. Translating these results to a mammalian model, we increased miR-125b levels in the rat through mimic treatments following spinal cord transection. These treatments downregulated Sema4D and other glial-scar-related genes, and enhanced the animal’s functional recovery. Our study identifies a key regulatory molecule conserved between salamander and mammal, and shows that the expression of miR-125b and Sema4D must be carefully controlled in the right cells at the correct level to promote regeneration. We also show that these molecular components of the salamander’s regeneration-permissive environment can be experimentally harnessed to improve treatment outcomes for mammalian spinal cord injuries.

  1. An Introduction to Requirements Traceability

    NARCIS (Netherlands)

    Wieringa, Roelf J.

    This report surveys the requirements traceability literature and gives some recommendations for further research and for an approach to consultancy concerning traceability in the 2RARE project. The problem of maintaining traceability in a development project is viewed as the problem of maintaining

  2. Invasive rats strengthen predation pressure on bird eggs in a South Pacific island rainforest

    OpenAIRE

    Duron, Q.; Bourguet, E.; De Meringo, H.; Millon, A.; Vidal, Eric

    2017-01-01

    Invasive rats (Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects are undertaken on islands worldwide. However, such projects represent a huge investment and the decision-making process requires proper assessment of rat impacts. Here, we assessed the influence of two sympatric invasive rats (Rattus rattus and R. exulans) on native bird eggs in a ...

  3. Cytokine production of in vitro stimulated peripheral lymphocytes during the course of pregnancy and pseudopregnancy in the rat

    NARCIS (Netherlands)

    Faas, MM; Eenling, R; van der Schaaf, G; Moes, H; Heineman, MJ; Vos, P

    Problem Does maternal lymphocyte cytokine production after in vitro stimulation vary with the stage of pregnancy in the rat? Method of study Blood samples were taken during the estrus cycle in rats (n = 11). Thereafter, rats were rendered pregnant (n = 6) or pseudopregnant (n = 5) and blood samples

  4. Alcohol and acute pancreatitis. An experimental study in the rat.

    Science.gov (United States)

    Jalovaara, P; Apaja, M

    1978-01-01

    The effect of chronic alcohol pretreatment and various pancreatobiliary secretions on the severity of experimental pancreatitis was studied in the rat. 95 rats were pretreated with ethanol (20% w/v, 1.1 ml/100 g body weight) five times weekly for 10 to 12 weeks by gastric intubation. 88 rats served as controls. Pancreatic lesions were produced by retograde injection of different pancreatobiliary secretions into the pancreatic ducts. The secretions were collected from both normal and chronically alcohol-fed rats, and each was used for induction of experimental pancreatitis in the control and alcohol pretreated rats. Bile obtained from normal rats was no more toxic to the pancreas than 0.9% saline solution, while bile obtained from the chronically alcohol-fed rats caused significantly more serious lesions to the pancreas than did normal rat bile. Bile-pancreatic juice (mixture of secretions at papilla of Vater) of normal and chronically alcohol-fed rats was as toxic as the bile of the alcohol-fed rats. Alcohol pretreatment had no significant effect on the severity of pancreatitis when control and alcohol-fed groups separately or the whole material according to pretreatment was examined. These results suggest that the metabolic effects of ethanol on the pancreas as such do not sensitize the pancreas to acute pancreatitis. An exogenous mechanism is required. The reflux of toxic alcoholic bile into the pancreas might act as an induction factor in acute alcohol pancreatitis.

  5. Assessing Requirements Quality through Requirements Coverage

    Science.gov (United States)

    Rajan, Ajitha; Heimdahl, Mats; Woodham, Kurt

    2008-01-01

    In model-based development, the development effort is centered around a formal description of the proposed software system the model. This model is derived from some high-level requirements describing the expected behavior of the software. For validation and verification purposes, this model can then be subjected to various types of analysis, for example, completeness and consistency analysis [6], model checking [3], theorem proving [1], and test-case generation [4, 7]. This development paradigm is making rapid inroads in certain industries, e.g., automotive, avionics, space applications, and medical technology. This shift towards model-based development naturally leads to changes in the verification and validation (V&V) process. The model validation problem determining that the model accurately captures the customer's high-level requirements has received little attention and the sufficiency of the validation activities has been largely determined through ad-hoc methods. Since the model serves as the central artifact, its correctness with respect to the users needs is absolutely crucial. In our investigation, we attempt to answer the following two questions with respect to validation (1) Are the requirements sufficiently defined for the system? and (2) How well does the model implement the behaviors specified by the requirements? The second question can be addressed using formal verification. Nevertheless, the size and complexity of many industrial systems make formal verification infeasible even if we have a formal model and formalized requirements. Thus, presently, there is no objective way of answering these two questions. To this end, we propose an approach based on testing that, when given a set of formal requirements, explores the relationship between requirements-based structural test-adequacy coverage and model-based structural test-adequacy coverage. The proposed technique uses requirements coverage metrics defined in [9] on formal high-level software

  6. Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system

    Directory of Open Access Journals (Sweden)

    Tsuruta James K

    2012-01-01

    Full Text Available Abstract Background Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive. Methods Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration and temperature of treatment. Results We found that 3 MHz ultrasound delivered with 2.2 Watt per square cm power for fifteen minutes was necessary to deplete spermatocytes and spermatids from the testis and that this treatment significantly reduced epididymal sperm reserves. 3 MHz ultrasound treatment reduced total epididymal sperm count 10-fold lower than the wet-heat control and decreased motile sperm counts 1,000-fold lower than wet-heat alone. The current treatment regimen provided nominally more energy to the treatment chamber than Fahim's originally reported conditions of 1 MHz ultrasound delivered at 1 Watt per square cm for ten minutes. However, the true spatial average intensity, effective radiating area and power output of the transducers used by Fahim were not reported, making a direct comparison impossible. We found that germ cell depletion was most uniform and effective when we rotated the therapeutic transducer to mitigate non-uniformity of the beam field. The lowest sperm count was achieved when the coupling medium (3% saline was held at 37 degrees C and two consecutive 15-minute treatments of 3 MHz ultrasound at 2.2 Watt per square cm were separated by 2 days. Conclusions The non-invasive nature of ultrasound and its efficacy in reducing sperm count make therapeutic ultrasound a promising candidate for a male contraceptive. However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the

  7. Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system.

    Science.gov (United States)

    Tsuruta, James K; Dayton, Paul A; Gallippi, Caterina M; O'Rand, Michael G; Streicker, Michael A; Gessner, Ryan C; Gregory, Thomas S; Silva, Erick J R; Hamil, Katherine G; Moser, Glenda J; Sokal, David C

    2012-01-30

    Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive. Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration and temperature of treatment. We found that 3 MHz ultrasound delivered with 2.2 Watt per square cm power for fifteen minutes was necessary to deplete spermatocytes and spermatids from the testis and that this treatment significantly reduced epididymal sperm reserves. 3 MHz ultrasound treatment reduced total epididymal sperm count 10-fold lower than the wet-heat control and decreased motile sperm counts 1,000-fold lower than wet-heat alone. The current treatment regimen provided nominally more energy to the treatment chamber than Fahim's originally reported conditions of 1 MHz ultrasound delivered at 1 Watt per square cm for ten minutes. However, the true spatial average intensity, effective radiating area and power output of the transducers used by Fahim were not reported, making a direct comparison impossible. We found that germ cell depletion was most uniform and effective when we rotated the therapeutic transducer to mitigate non-uniformity of the beam field. The lowest sperm count was achieved when the coupling medium (3% saline) was held at 37 degrees C and two consecutive 15-minute treatments of 3 MHz ultrasound at 2.2 Watt per square cm were separated by 2 days. The non-invasive nature of ultrasound and its efficacy in reducing sperm count make therapeutic ultrasound a promising candidate for a male contraceptive. However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the result of repeated use, to verify that the contraceptive effect is

  8. Conversion of leucine to β‐hydroxy‐β‐methylbutyrate by α‐keto isocaproate dioxygenase is required for a potent stimulation of protein synthesis in L6 rat myotubes

    Science.gov (United States)

    Vílchez, José D.; Salto, Rafael; Manzano, Manuel; Sevillano, Natalia; Campos, Nefertiti; Argilés, Josep M.; Rueda, Ricardo; López‐Pedrosa, José M.

    2015-01-01

    Abstract Background L‐Leu and its metabolite β‐hydroxy‐β‐methylbutyrate (HMB) stimulate muscle protein synthesis enhancing the phosphorylation of proteins that regulate anabolic signalling pathways. Alterations in these pathways are observed in many catabolic diseases, and HMB and L‐Leu have proven their anabolic effects in in vivo and in vitro models. The aim of this study was to compare the anabolic effects of L‐Leu and HMB in myotubes grown in the absence of any catabolic stimuli. Methods Studies were conducted in vitro using rat L6 myotubes under normal growth conditions (non‐involving L‐Leu‐deprived conditions). Protein synthesis and mechanistic target of rapamycin signalling pathway were determined. Results Only HMB was able to increase protein synthesis through a mechanism that involves the phosphorylation of the mechanistic target of rapamycin as well as its downstream elements, pS6 kinase, 4E binding protein‐1, and eIF4E. HMB was significantly more effective than L‐Leu in promoting these effects through an activation of protein kinase B/Akt. Because the conversion of L‐Leu to HMB is limited in muscle, L6 cells were transfected with a plasmid that codes for α‐keto isocaproate dioxygenase, the key enzyme involved in the catabolic conversion of α‐keto isocaproate into HMB. In these transfected cells, L‐Leu was able to promote protein synthesis and mechanistic target of rapamycin regulated pathway activation equally to HMB. Additionally, these effects of leucine were reverted to a normal state by mesotrione, a specific inhibitor of α‐keto isocaproate dioxygenase. Conclusion Our results suggest that HMB is an active L‐Leu metabolite able to maximize protein synthesis in skeletal muscle under conditions, in which no amino acid deprivation occurred. It may be proposed that supplementation with HMB may be very useful to stimulate protein synthesis in wasting conditions associated with chronic diseases, such as cancer or

  9. Consecuencias de la obesidad en el niño y el adolescente: un problema que requiere atención Consequences of obesity in children and teenagers: a problem that requires attention

    Directory of Open Access Journals (Sweden)

    Reyna Liria

    2012-09-01

    Full Text Available La obesidad es una pandemia mundial y los niños son un grupo vulnerable. En América se estimó que en el año 2010 el 15,2% de los menores 18 años la podría sufrir. La obesidad en la niñez y la adolescencia tiene un impacto negativo en la salud y carga de enfermedades en esa etapa de vida y, posteriormente, en la adultez, cobrando un impacto negativo en la economía de un país debido a que se incrementa el riesgo de enfermedades crónicas, los gastos de salud y los costos indirectos como consecuencia de la enfermedad. El Perú está en un proceso de transición epidemiológica, donde no se ha solucionado los problemas de desnutrición y ya cuenta con altas tasas de obesidad infantil (10% en niños menores de cinco años; estando dentro de uno de los países con mayor incremento de la obesidad infantil en los últimos años a nivel Latinoamericano. La niñez y adolescencia son consideradas periodos críticos porque en estas etapas se instalan los hábitos alimentarios y de actividad física, y porque gran parte de los niños y adolescentes obesos seguirán siéndolo al llegar a adultos. Por ello, es crucial buscar estrategias e intervenciones que prevengan el sobrepeso y la obesidad infantil y del adolescente para así mejorar las condiciones de salud de un paísObesity is a worldwide pandemic and children are a vulnerable group. In America, it was estimated that in 2010, 15.2% of 18 year-old children could suffer from this. Obesity in children and teenagers has a negative impact on health and on the load of diseases at this stage of life, and later on in adulthood, having a negative impact on the economy of a country due to the rise of risks of chronic diseases, health expenses and indirect costs as a result of the disease. Peru is going through an epidemiological transition, with unsolved malnutrition problems and high child obesity rates (10% of children under five, thus being one of the countries with a higher increase of child obesity

  10. Postnatal treadmill exercise alleviates short-term memory impairment by enhancing cell proliferation and suppressing apoptosis in the hippocampus of rat pups born to diabetic rats.

    Science.gov (United States)

    Kim, Young Hoon; Sung, Yun-Hee; Lee, Hee-Hyuk; Ko, Il-Gyu; Kim, Sung-Eun; Shin, Mal-Soon; Kim, Bo-Kyun

    2014-08-01

    During pregnancy, diabetes mellitus exerts detrimental effects on the development of the fetus, especially the central nervous system. In the current study, we evaluated the effects of postnatal treadmill exercise on short-term memory in relation with cell proliferation and apoptosis in the hippocampus of rat pups born to streptozotocin (STZ)-induced diabetic maternal rats. Adult female rats were mated with male rats for 24 h. Two weeks after mating, the pregnant female rats were divided into two groups: control group and STZ injection group. The pregnant rats in the STZ injection group were administered 40 mg/kg of STZ intraperitoneally. After birth, the rat pups were divided into the following four groups: control group, control with postnatal exercise group, maternal STZ-injection group, and maternal STZ-injection with postnatal exercise group. The rat pups in the postnatal exercise groups were made to run on a treadmill for 30 min once a day, 5 times per week for 2 weeks beginning 4 weeks after birth. The rat pups born to diabetic rats were shown to have short-term memory impairment with suppressed cell proliferation and increased apoptosis in the hippocampal dentate gyrus. Postnatal treadmill exercise alleviated short-term memory impairment by increased cell proliferation and suppressed apoptosis in the rat pups born to diabetic rats. These findings indicate that postnatal treadmill exercise may be used as a valuable strategy to ameliorate neurodevelopmental problems in children born to diabetics.

  11. Impairment of the organization of locomotor and exploratory behaviors in bile duct-ligated rats

    DEFF Research Database (Denmark)

    Leke, Renata; de Oliveira, Diogo L; Mussulini, Ben Hur M.

    2012-01-01

    Hepatic encephalopathy (HE) arises from acute or chronic liver diseases and leads to several problems, including motor impairment. Animal models of chronic liver disease have extensively investigated the mechanisms of this disease. Impairment of locomotor activity has been described in different...... female Wistar rats underwent common bile duct ligation (BDL rats) or the manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent open-field, plus-maze and foot-fault behavioral tasks. The BDL rats developed chronic liver failure...

  12. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    for a minimum height container required for the items. The main contributions of the thesis are three new heuristics for strip-packing and knapsack packing problems where items are both rectangular and irregular. In the two first papers we describe a heuristic for the multidimensional strip-packing problem...... that is based on a relaxed placement principle. The heuristic starts with a random overlapping placement of items and large container dimensions. From the overlapping placement overlap is reduced iteratively until a non-overlapping placement is found and a new problem is solved with a smaller container size...... of this heuristic are among the best published in the literature both for two- and three-dimensional strip-packing problems for irregular shapes. In the third paper, we introduce a heuristic for two- and three-dimensional rectangular knapsack packing problems. The two-dimensional heuristic uses the sequence pair...

  13. Vision Problems in Homeless Children.

    Science.gov (United States)

    Smith, Natalie L; Smith, Thomas J; DeSantis, Diana; Suhocki, Marissa; Fenske, Danielle

    2015-08-01

    Vision problems in homeless children can decrease educational achievement and quality of life. To estimate the prevalence and specific diagnoses of vision problems in children in an urban homeless shelter. A prospective series of 107 homeless children and teenagers who underwent screening with a vision questionnaire, eye chart screening (if mature enough) and if vision problem suspected, evaluation by a pediatric ophthalmologist. Glasses and other therapeutic interventions were provided if necessary. The prevalence of vision problems in this population was 25%. Common diagnoses included astigmatism, amblyopia, anisometropia, myopia, and hyperopia. Glasses were required and provided for 24 children (22%). Vision problems in homeless children are common and frequently correctable with ophthalmic intervention. Evaluation by pediatric ophthalmologist is crucial for accurate diagnoses and treatment. Our system of screening and evaluation is feasible, efficacious, and reproducible in other homeless care situations.

  14. Problems in nonlinear resistive MHD

    International Nuclear Information System (INIS)

    Turnbull, A.D.; Strait, E.J.; La Haye, R.J.; Chu, M.S.; Miller, R.L.

    1998-01-01

    Two experimentally relevant problems can relatively easily be tackled by nonlinear MHD codes. Both problems require plasma rotation in addition to the nonlinear mode coupling and full geometry already incorporated into the codes, but no additional physics seems to be crucial. These problems discussed here are: (1) nonlinear coupling and interaction of multiple MHD modes near the B limit and (2) nonlinear coupling of the m/n = 1/1 sawtooth mode with higher n gongs and development of seed islands outside q = 1

  15. The effects of presenting multidigit mathematics problems in a realistic context on sixth graders' problem solving

    NARCIS (Netherlands)

    Hickendorff, M.

    2013-01-01

    Mathematics education and assessments increasingly involve arithmetic problems presented in context: a realistic situation that requires mathematical modeling. This study assessed the effects of such typical school mathematics contexts on two aspects of problem solving: performance and strategy use.

  16. Engaged Problem Formulation in IS Research

    DEFF Research Database (Denmark)

    Nielsen, Peter Axel; Persson, John Stouby

    2016-01-01

    problems requires a more substantial engagement with the different stakeholders, especially when their problems are ill structured and situated in complex organizational settings. On this basis, we present an engaged approach to formulating IS problems with, not for, IS practitioners. We have come...

  17. The Pyramidal Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...

  18. The pyramidal capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2010-01-01

    This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal...

  19. The effect of chemotherapy on rat brain PET: preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Kim, Il Han; Yu, A Ram; Park, Ji Ae; Woo, Sang Keun; Kim, Jong Guk; Cheon, Gi Jeong; Kim, Byeong Il; Choi, Chang Woon; Lim, Sang Moo; Kim, Hee Joung; Kim, Kyeong Min [Korea Institute Radiological and Medical Science, Seoul (Korea, Republic of)

    2010-10-15

    Chemotherapy was widely used for the therapy of cancer patients. When chemotherapy was performed, transient cognitive memory problem was occurred. This cognitive problem in brain was called as chemobrain. In this study, we have developed rat model for chemobrain. Cerebral glucose metabolism after chemotherapy was assessed using animal PET and voxel based statistical analysis method

  20. The effect of chemotherapy on rat brain PET: preliminary study

    International Nuclear Information System (INIS)

    Kim, Jin Su; Kim, Il Han; Yu, A Ram; Park, Ji Ae; Woo, Sang Keun; Kim, Jong Guk; Cheon, Gi Jeong; Kim, Byeong Il; Choi, Chang Woon; Lim, Sang Moo; Kim, Hee Joung; Kim, Kyeong Min

    2010-01-01

    Chemotherapy was widely used for the therapy of cancer patients. When chemotherapy was performed, transient cognitive memory problem was occurred. This cognitive problem in brain was called as chemobrain. In this study, we have developed rat model for chemobrain. Cerebral glucose metabolism after chemotherapy was assessed using animal PET and voxel based statistical analysis method

  1. Human embryonic mesenchymal stem cell-derived conditioned medium rescues kidney function in rats with established chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Arianne van Koppen

    Full Text Available Chronic kidney disease (CKD is a major health care problem, affecting more than 35% of the elderly population worldwide. New interventions to slow or prevent disease progression are urgently needed. Beneficial effects of mesenchymal stem cells (MSC have been described, however it is unclear whether the MSCs themselves or their secretome is required. We hypothesized that MSC-derived conditioned medium (CM reduces progression of CKD and studied functional and structural effects in a rat model of established CKD. CKD was induced by 5/6 nephrectomy (SNX combined with L-NNA and 6% NaCl diet in Lewis rats. Six weeks after SNX, CKD rats received either 50 µg CM or 50 µg non-CM (NCM twice daily intravenously for four consecutive days. Six weeks after treatment CM administration was functionally effective: glomerular filtration rate (inulin clearance and effective renal plasma flow (PAH clearance were significantly higher in CM vs. NCM-treatment. Systolic blood pressure was lower in CM compared to NCM. Proteinuria tended to be lower after CM. Tubular and glomerular damage were reduced and more glomerular endothelial cells were found after CM. DNA damage repair was increased after CM. MSC-CM derived exosomes, tested in the same experimental setting, showed no protective effect on the kidney. In a rat model of established CKD, we demonstrated that administration of MSC-CM has a long-lasting therapeutic rescue function shown by decreased progression of CKD and reduced hypertension and glomerular injury.

  2. Invasive rats on tropical islands: Their population biology and impacts on native species

    Directory of Open Access Journals (Sweden)

    Grant A. Harper

    2015-01-01

    Full Text Available The three most invasive rat species, black or ship rat Rattus rattus, brown or Norway rats, R. norvegicus and Pacific rat, R. exulans have been incrementally introduced to islands as humans have explored the world’s oceans. They have caused serious deleterious effects through predation and competition, and extinction of many species on tropical islands, many of which are biodiversity hotspots. All three rat species are found in virtually all habitat types, including mangrove and arid shrub land. Black rats tend to dominate the literature but despite this the population biology of invasive rats, particularly Norway rats, is poorly researched on tropical islands. Pacific rats can often exceed population densities of well over 100 rats ha−1 and black rats can attain densities of 119 rats ha−1, which is much higher than recorded on most temperate islands. High densities are possibly due to high recruitment of young although the data to support this are limited. The generally aseasonally warm climate can lead to year-round breeding but can be restricted by either density-dependent effects interacting with resource constraints often due to aridity. Apparent adverse impacts on birds have been well recorded and almost all tropical seabirds and land birds can be affected by rats. On the Pacific islands, black rats have added to declines and extinctions of land birds caused initially by Pacific rats. Rats have likely caused unrecorded extinctions of native species on tropical islands. Further research required on invasive rats on tropical islands includes the drivers of population growth and carrying capacities that result in high densities and how these differ to temperate islands, habitat use of rats in tropical vegetation types and interactions with other tropical species, particularly the reptiles and invertebrates, including crustaceans.

  3. Efficacy and security of ivermectin given orally to rats naturally infected with Syphacia spp., Giardia spp. and Hymenolepis nana.

    Science.gov (United States)

    Foletto, V R S; Vanz, F; Gazarini, L; Stern, C A J; Tonussi, C R

    2015-07-01

    The results of this study show that the oral administration of ivermectin (48 mg/L) repeatedly for 72 h used in accordance with the present protocol is a safe and highly effective treatment for Giardia spp. and Hymenolepis nana in laboratory rat colonies. The drug can be easily and safely administered using drinking water. This simple regimen should control pinworm infection (Syphacia muris), a problem that can be endemic in laboratory colonies. Experiments using healthy animals are likely to generate more consistent results, thereby requiring a reduced number of animals per group. © The Author(s) 2014.

  4. Spent nuclear fuel transport problems

    International Nuclear Information System (INIS)

    Kondrat'ev, A.N.; Kosarev, Yu.A.; Yulikov, E.I.

    1977-01-01

    The paper considers the problems of shipping spent fuel from nuclear power stations to reprocessing plants and also the principal ways of solving these problems with a view to achieving maximum economy and safety in transport. The increase in the number of nuclear power plants in the USSR will entail an intensification of spent-fuel shipments. Higher burnup and the need to reduce cooling time call for heavier and more complex shipping containers. The problem of shipping spent fuel should be tackled comprehensively, bearing in mind the requirements of safety and economy. One solution to these problems is to develop rational and cheap designs of such containers. In addition, the world-wide trend towards more thorough protection of the environment against pollution and of the health of the population requires the devotion of constant attention to improving the reliability and safety of shipments. The paper considers the prospects for nuclear power development in the USSR and in other member countries of the CMEA (1976-1980), the composition and design of some Soviet packaging assemblies, the appropriate cooling time for spent fuel from thermal reactor power stations, procedures for reducing fuel-shipping costs, some methodological problems of container calculation and design, and finally problems of testing and checking containers on test rigs. (author)

  5. Comparison of Mucosal, Subcutaneous and Intraperitoneal Routes of Rat Leptospira Infection

    Science.gov (United States)

    Zilber, Anne-Laure; Belli, Patrick; Grezel, Delphine; Artois, Marc; Kodjo, Angeli; Djelouadji, Zoheira

    2016-01-01

    Leptospirosis is a zoonosis found worldwide that is caused by a spirochete. The main reservoirs of Leptospira, which presents an asymptomatic infection, are wild rodents, including the brown rat (Rattus norvegicus). Experimental studies of the mechanisms of its renal colonization in rats have previously used an intraperitoneal inoculation route. However, knowledge of rat-rat transmission requires the use of a natural route of inoculation, such as a mucosal or subcutaneous route. We investigated for the first time the effects of subcutaneous and mucosal inoculation routes compared to the reference intraperitoneal route during Leptospira infection in adult rats. Infection characteristics were studied using Leptospira renal isolation, serology, and molecular and histological analyses. Leptospira infection was asymptomatic using each inoculation route, and caused similar antibody production regardless of renal colonization. The observed renal colonization rates were 8 out of 8 rats, 5 out of 8 rats and 1 out of 8 rats for the intraperitoneal, mucosal and subcutaneous inoculation routes, respectively. Thus, among the natural infection routes studied, mucosal inoculation was more efficient for renal colonization associated with urinary excretion than the subcutaneous route and induced a slower-progressing infection than the intraperitoneal route. These results can facilitate understanding of the infection modalities in rats, unlike the epidemiological studies conducted in wild rats. Future studies of other natural inoculation routes in rat models will increase our knowledge of rat-rat disease transmission and allow the investigation of infection kinetics. PMID:27031867

  6. Insulin pumps and insulin quality--requirements and problems.

    Science.gov (United States)

    Brange, J; Havelund, S

    1983-01-01

    In developing insulin solution suitable for delivery devices the chemical and biological stability, as well as the physical stability, must be taken into consideration. Addition of certain mono- and disaccharides increases the physical stability of neutral insulin solutions, but concurrently the chemical and biological stability decrease to an unacceptable degree. Addition of Ca-ions in low concentrations offers a physiologically acceptable method for stabilizing neutral insulin solutions against heat precipitation without affecting the quality, including the chemical and biological stability.

  7. Immunology taught by rats

    OpenAIRE

    Klenerman, P; Barnes, EJ

    2017-01-01

    Immunology may be best taught by viruses, and possibly by humans, but the rats of New York City surprisingly also have plenty to offer. A survey published in 2014 of the pathogens carried by rats trapped in houses and parks in Manhattan identified a huge burden of infectious agents in these animals, including several novel viruses. Among these are Norway rat hepaciviruses (NrHVs), which belong to the same family as hepatitis C virus (HCV). NrHVs were found in rat livers, raising the possibili...

  8. Financing and insurance problems

    International Nuclear Information System (INIS)

    Laurenge, M.-T.

    1975-01-01

    The author analyses the papers presented at the Paris Conference on the maturity of nuclear energy. It is evident that financing possibilities will be a determinant factor in the rate of development of nuclear power during the years to come. After having evaluated the capital requirements necessitated for the development of nuclear programmes, the parties intervening have examined the means at the disposal of electricity manufacturers to meet these needs (self-financing, recourse to external financing, regrouping, on an international scale of the electricity manufacturers of the setting up of high capacity plants). As concerns the insurance problems, they are becoming more and more involved as nuclear applications, are further diversified and intensified. The parties intervening have discussed new tarification techniques likely to be applied and pointed out the possibilities offered by regrouping or pooling of insurers (Market Pool) which allow for a maximum of risks to be covered without exceeding the means proper to each company concerned [fr

  9. Distance Constraint Satisfaction Problems

    Science.gov (United States)

    Bodirsky, Manuel; Dalmau, Victor; Martin, Barnaby; Pinsker, Michael

    We study the complexity of constraint satisfaction problems for templates Γ that are first-order definable in ({ Z}; {suc}), the integers with the successor relation. Assuming a widely believed conjecture from finite domain constraint satisfaction (we require the tractability conjecture by Bulatov, Jeavons and Krokhin in the special case of transitive finite templates), we provide a full classification for the case that Γ is locally finite (i.e., the Gaifman graph of Γ has finite degree). We show that one of the following is true: The structure Γ is homomorphically equivalent to a structure with a certain majority polymorphism (which we call modular median) and CSP(Γ) can be solved in polynomial time, or Γ is homomorphically equivalent to a finite transitive structure, or CSP(Γ) is NP-complete.

  10. Alveolar bone healing process in spontaneously hypertensive rats (SHR). A radiographic densitometry study.

    Science.gov (United States)

    Manrique, Natalia; Pereira, Cassiano Costa Silva; Garcia, Lourdes Maria Gonzáles; Micaroni, Samuel; Carvalho, Antonio Augusto Ferreira de; Perri, Sílvia Helena Venturoli; Okamoto, Roberta; Sumida, Doris Hissako; Antoniali, Cristina

    2012-01-01

    Hypertension is one of the most important public health problems worldwide. If undiagnosed or untreated, this pathology represents a systemic risk factor and offers unfavorable conditions for dental treatments, especially those requiring bone healing. The purpose of this study was to demonstrate, by analysis of bone mineral density (BMD), that the alveolar bone healing process is altered in spontaneously hypertensive rats (SHRs). Wistar rats and SHRs were submitted to extraction of the upper right incisor and were euthanized 7, 14, 21, 28 and 42 days after surgery. Right maxillae were collected, radiographed and analyzed using Digora software. BMD was expressed as minimum (min), middle (med) and maximum (max) in the medium (MT) and apical (AT) thirds of the dental alveolus. The results were compared across days and groups. Wistar showed difference in med and max BMD in the MT between 7 and 28 and also between 14 and 28 days. The AT exhibited significant difference in med and min BMD between 7 and 28 days, as well as difference in min BMD between 28 and 42 days. SHRs showed lower med BMD in the MT at 28 days when compared to 21 and 42 days. Differences were observed across groups in med and min BMD at day 28 in the MT and AT; and in max BMD at 14, 21 and 42 days in the MT. These results suggest that the alveolar bone healing process is delayed in SHRs comparing with Wistar rats.

  11. Effect of opium dependency on secondary intention wound healing in a rat model: an experimental study.

    Science.gov (United States)

    Vahedian, Jalal; Mirshekari, Tooraj-Reza; Nabavizadeh, Fatemeh

    2013-06-01

    Opium dependency is a social and health problem in some middle eastern countries like Iran. Many of these people may require surgery. This study investigates the effects of opium dependency on histological parameters of secondary intention wound healing in rat. A full-thickness wound (2 × 2 cm in diameters) was created on the dorsum of two groups of rats, a normal control group and a second group of rat depended to opium (Badawy's method). Several times during 14 days postwounding, the wound was excised with peripheral margins of normal skin and was evaluated for cellular population, reepithelialisation and revascularisation. Results are presented as the mean ± standard error. Data were compared by an unpaired t-test or analysis of variance. Histological examination of the wound tissue showed evidence of increased population of fibroblasts, decreased recruitment of neutrophile and plateau of macrophage cells in opium depended animals comparing with control group. In the depended animals, reepithelialisation was seen to be enhanced significantly, while prohibiting progression of revascularisation. This study shows that opium dependency enhances reepitheliazation as well as tissue recruitment of fibroblasts; thereby probable enhancement of secondary intention wound healing. © 2012 The Authors. International Wound Journal © 2012 John Wiley & Sons Ltd and Medicalhelplines.com Inc.

  12. International safeguards problem

    International Nuclear Information System (INIS)

    Scheinman, L.; Curtis, H.B.

    1977-01-01

    To recognize the limitations of safeguards as a barrier to nuclear proliferation is not to deny their essential role in the effort to contain that problem. Without a safeguards system, international nuclear commerce and development would not, indeed could not, be what they are today. The problems evoked in the discussion of the spread of sensitive nuclear technology underscore the importance of ensuring that activities do not outpace our ability to control them. To sustain a global nuclear economy requires a readiness to live within the constraints that such an economy requires. Enhanced safeguards and strengthened national commitments to facilitate their application are key elements of those constraints. So also may be a prepardness by many nations to forego explicitly national control over all facets of the nuclear fuel cycle while still sharing fully and equally in the benefits of the peaceful atom. The challenge of the coming years will be to craft mechanisms and institutions enabling the continued growth of peaceful nuclear activity without further impairing international security. The constraints that such an outcome entails are not limited to nations lacking sophisticated nuclear technology; they apply to the most advanced nuclear nations as well--partly through adherence to the safeguards system that these countries call upon others to adopt, and partly through greater willingness to entertain solutions that may involve greater international involvement in, and control over, their own peaceful nuclear productive activities. With time, the relative incompatibility of nuclear energy with full national sovereignty, and the far-sighted wisdom of the Baruch Plan, are becoming increasingly clear. 1 table, 10 references

  13. Urban Environmental Problems

    International Nuclear Information System (INIS)

    Situma, F.D.P.

    1999-01-01

    The rapid urbanization and resultant heavy concentration of population in urban centres have led to many urban areas failing to provide the necessary infrastructure and amenities as the demands placed on them have overwhelmed their financial and institutional capacities. In many urban areas, the capacity for resource mobilization and delivery of social services has either broken down completely or tethers on breaking point. Although in 1986 the GoK launched a new strategy for the balanced development of rural and urban areas aimed at avoiding excessive concentration of population in urban areas, the fruits of this strategy are yet to be realized. As a result, developments in urban areas have been unsustainable and environmentally unsound. The general quality of the environment has deteriorated so much so that urgent policy intervention is required. Appropriate environmental management measures and practices are needed to address the current trend of spiralling environmental problems in the context of the existing legal and institutional frameworks and makes some proposals for reform to address these problems in order to make urban areas environmentally

  14. Preventing Diabetes Problems

    Science.gov (United States)

    ... Problems Diabetes, Sexual, & Bladder Problems Clinical Trials Preventing Diabetes Problems View or Print All Sections Heart Disease & ... to help control symptoms and restore intimacy. Depression & Diabetes Depression is common among people with a chronic, ...

  15. The Chicken Problem.

    Science.gov (United States)

    Reeves, Charles A.

    2000-01-01

    Uses the chicken problem for sixth grade students to scratch the surface of systems of equations using intuitive approaches. Provides students responses to the problem and suggests similar problems for extensions. (ASK)

  16. Problems in differential equations

    CERN Document Server

    Brenner, J L

    2013-01-01

    More than 900 problems and answers explore applications of differential equations to vibrations, electrical engineering, mechanics, and physics. Problem types include both routine and nonroutine, and stars indicate advanced problems. 1963 edition.

  17. Subjective costs drive overly patient foraging strategies in rats on an intertemporal foraging task

    OpenAIRE

    Wikenheiser, Andrew M.; Stephens, David W.; Redish, A. David

    2013-01-01

    Laboratory studies of decision making often take the form of two-alternative, forced-choice paradigms. In natural settings, however, many decision problems arise as stay/go choices. We designed a foraging task to test intertemporal decision making in rats via stay/go decisions. Subjects did not follow the rate-maximizing strategy of choosing only food items associated with short delays. Instead, rats were often willing to wait for surprisingly long periods, and consequently earned a lower rat...

  18. Teaching giant african pouched rats to find landmines: operant conditioning with real consequences.

    Science.gov (United States)

    Poling, Alan; Weetjens, Bart J; Cox, Christophe; Beyene, Negussie; Bach, Håvard; Sully, Andrew

    2010-01-01

    Giant African pouched rats recently have been used as mine-detection animals in Mozambique. To provide an example of the wide range of problems to which operant conditioning procedures can be applied and to illustrate the common challenges often faced in applying those procedures, this manuscript briefly describes how the rats are trained and used operationally. To date, the rats have performed well and it appears they can play a valuable role in humanitarian demining.

  19. Chasing red herrings: Memory of distractors causes fixation in creative problem solving.

    Science.gov (United States)

    Beda, Zsolt; Smith, Steven M

    2018-03-07

    Two experiments tested the red herring retrieval hypothesis, which states that fixation in creative problem solving is worse when memory for red herrings (i.e., inappropriate or incorrect solutions) is strengthened. In Experiment 1, when associations between Remote Associates Test (RAT) problem words (e.g., COTTAGE, SWISS, CAKE) and related red herring words (e.g., hut, chocolate, icing) were strengthened via repetition, an encoding variable, fixation was found to increase. In Experiment 2, when associations were formed between RAT problem contexts and red herrings, then subsequent reinstatement of problem contexts during RAT problem solving trials (as compared with showing new contexts) also worsened fixation effects. Our results add to the increasing body of research that connects memory with creative problem solving, and they suggest possible ways for overcoming fixation effects.

  20. Preanalytical requirements of urinalysis

    Science.gov (United States)

    Delanghe, Joris; Speeckaert, Marijn

    2014-01-01

    Urine may be a waste product, but it contains an enormous amount of information. Well-standardized procedures for collection, transport, sample preparation and analysis should become the basis of an effective diagnostic strategy for urinalysis. As reproducibility of urinalysis has been greatly improved due to recent technological progress, preanalytical requirements of urinalysis have gained importance and have become stricter. Since the patients themselves often sample urine specimens, urinalysis is very susceptible to preanalytical issues. Various sampling methods and inappropriate specimen transport can cause important preanalytical errors. The use of preservatives may be helpful for particular analytes. Unfortunately, a universal preservative that allows a complete urinalysis does not (yet) exist. The preanalytical aspects are also of major importance for newer applications (e.g. metabolomics). The present review deals with the current preanalytical problems and requirements for the most common urinary analytes. PMID:24627718

  1. RatMap—rat genome tools and data

    Science.gov (United States)

    Petersen, Greta; Johnson, Per; Andersson, Lars; Klinga-Levan, Karin; Gómez-Fabre, Pedro M.; Ståhl, Fredrik

    2005-01-01

    The rat genome database RatMap (http://ratmap.org or http://ratmap.gen.gu.se) has been one of the main resources for rat genome information since 1994. The database is maintained by CMB–Genetics at Göteborg University in Sweden and provides information on rat genes, polymorphic rat DNA-markers and rat quantitative trait loci (QTLs), all curated at RatMap. The database is under the supervision of the Rat Gene and Nomenclature Committee (RGNC); thus much attention is paid to rat gene nomenclature. RatMap presents information on rat idiograms, karyotypes and provides a unified presentation of the rat genome sequence and integrated rat linkage maps. A set of tools is also available to facilitate the identification and characterization of rat QTLs, as well as the estimation of exon/intron number and sizes in individual rat genes. Furthermore, comparative gene maps of rat in regard to mouse and human are provided. PMID:15608244

  2. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  3. Colon of the rat

    International Nuclear Information System (INIS)

    Lindstroem, C.G.; Rosengren, J.-E.; Fork, F.-T.

    1979-01-01

    The anatomy and radiologic appearance of the colon in rats are described on the basis of 300 animals treated with carcinogenic agents and 40 normal rats. The macroscopic and microscopic appearance of the mucosa varies in the different parts of the colon. Lymphoid plaques are normal structures. The results justify a new anatomic nomenclature. (Auth.)

  4. Curcumin inhibits amygdaloid kindled seizures in rats.

    Science.gov (United States)

    DU, Peng; Li, Xin; Lin, Hao-Jie; Peng, Wei-Feng; Liu, Jian-Ying; Ma, Yu; Fan, Wei; Wang, Xin

    2009-06-20

    Curcumin can reduce the severity of seizures induced by kainate acid (KA), but the role of curcumin in amygdaloid kindled models is still unknown. This study aimed to explore the effect of curcumin on the development of kindling in amygdaloid kindled rats. With an amygdaloid kindled Sprague-Dawley (SD) rat model and an electrophysiological method, different doses of curcumin (10 mgxkg(-1)xd(-1) and 30 mgxkg(-1)xd(-1) as low dose groups, 100 mgxkg(-1)xd(-1) and 300 mgxkg(-1)xd(-1) as high dose groups) were administrated intraperitoneally during the whole kindling days, by comparison with the course of kindling, afterdischarge (AD) thresholds and the number of ADs to reach the stages of class I to V seizures in the rats between control and experimental groups. One-way or two-way ANOVA and Fisher's least significant difference post hoc test were used for statistical analyses. Curcumin (both 100 mgxkg(-1)xd(-1) and 300 mgxkg(-1)xd(-1)) significantly inhibited the behavioral seizure development in the (19.80 +/- 2.25) and (21.70 +/- 2.21) stimulations respectively required to reach the kindled state. Rats treated with 100 mgxkg(-1)xd(-1) curcumin 30 minutes before kindling stimulation showed an obvious increase in the stimulation current intensity required to evoke AD from (703.3 +/- 85.9) microA to (960.0 +/- 116.5) microA during the progression to class V seizures. Rats treated with 300 mgxkg(-1)xd(-1) curcumin showed a significant increase in the stimulation current intensity required to evoke AD from (735.0 +/- 65.2) microA to (867.0 +/- 93.4) microA during the progression to class V seizures. Rats treated with 300 mgxkg(-1)xd(-1) curcumin required much more evoked ADs to reach the stage of class both IV (as (199.83 +/- 12.47) seconds) and V seizures (as (210.66 +/- 10.68) seconds). Rats treated with 100 mgxkg(-1)xd(-1) curcumin required much more evoked ADs to reach the stage of class V seizures (as (219.56 +/- 18.24) seconds). Our study suggests that curcumin has

  5. Health problems in Iraq.

    Science.gov (United States)

    Acheson, E D

    1992-02-22

    Iraq is faced with large scale public health problems that have been caused by the destruction to their infrastructure during the Gulf war. Humanitarian aid is needed in order to avoid a large scale human disaster. In 1988 73% of Iraq's population lived in urban areas. The loss of electrical generating capacity has affected hospitals, water purification and sewage treatment. Iraq had made great strides int he health of their people with an infant mortality rate of 42/1000 in 1990 and 52./1000 for children under 5. The international study team's survey of over 9000 households revealed surprising evidence of widespread chronic malnutrition. Based on accepted mortality as a baseline, data suggests that mortality among Iraqi infants and children under 5 doubled in 1991. The current food ration provides only half of the energy requirement and with rapidly accelerating inflation, the cost of food while only make the situation worse. The UN Disaster Relief Office has received $1.059 billion from donor countries; but, only half of the requested $14 million has been funded through Unicef. This money is needed to meet basic requirements for water, sanitation, antibiotics, and vaccines. The UN Security Council approved resolutions 706 and 712 which would have allowed Iraq to sell $1.6 billion for foodstuffs, medicines, and materials and supplies necessary to civilian needs subject to monitoring and supervision to ensure equitable distribution. The Iraqi government has not met the requirements of 706 and 712 because of the monitoring conditions, so no money has been issued. More money is needed if humanitarian organizations are to do their work. Only $29 million of the $145 million needed for the 1st half of this year has been pledged.

  6. New Approach to Analyzing Physics Problems: A Taxonomy of Introductory Physics Problems

    Science.gov (United States)

    Teodorescu, Raluca E.; Bennhold, Cornelius; Feldman, Gerald; Medsker, Larry

    2013-01-01

    This paper describes research on a classification of physics problems in the context of introductory physics courses. This classification, called the Taxonomy of Introductory Physics Problems (TIPP), relates physics problems to the cognitive processes required to solve them. TIPP was created in order to design educational objectives, to develop…

  7. Hemorrhage Near Fetal Rat Bone: Preliminary Results

    Science.gov (United States)

    Bigelow, Timothy A.; Miller, Rita J.; Blue, James P.; O'Brien, William D.

    2006-05-01

    High-intensity ultrasound has shown potential in treating many ailments requiring noninvasive tissue necrosis. However, little work has been done on using ultrasound to ablate pathologies on or near the developing fetus. For example, Congenital Cystic Adenomatoid Malformation (cyst on lungs), Sacrococcygeal Teratoma (benign tumor on tail bone), and Twin-Twin Transfusion Syndrome (one twin pumps blood to other twin) are selected problems that will potentially benefit from noninvasive ultrasound treatments. Before these applications can be explored, potential ultrasound-induced bioeffects should be understood. Specifically, ultrasound-induced hemorrhage near the fetal rat skull was investigated. An f/1 spherically focused transducer (5.1-cm focal length) was used to expose the skull of 18- to 19-day-gestation exteriorized rat fetuses. The ultrasound pulse had a center frequency of 0.92 MHz and pulse duration of 9.6 μs. The fetuses were exposed to 1 of 4 exposure conditions (denoted A, B, C, and D) in addition to a sham exposure. Three of the exposures consisted of a peak compressional pressure of 10 MPa, a peak rarefactional pressure of 6.7 MPa, and pulse repetition frequencies of 100 Hz (A), 250 Hz (B), and 500 Hz (C), corresponding to time-average intensities of 1.9 W/cm2, 4.7 W/cm2, and 9.4 W/cm2, respectively. Exposure D consisted of a peak compressional pressure of 6.7 MPa, a peak rarefactional pressure of 5.0 MPa, and a PRF of 500 Hz corresponding to a time-average intensity of 4.6 W/cm2. Hemorrhage occurrence increased slightly with increasing time-average intensity (i.e., 11% for A, 28% for B, 31% for C, and 19% for D with a 9% occurrence when the fetuses were not exposed). The low overall occurrence of hemorrhaging may be attributed to fetal motion (observed in over half of the fetuses from the backscattered echo during the exposure). The mean hemorrhage sizes were 3.1 mm2 for A, 2.5 mm2 for B, 2.7 mm2 for C, and 5.1 mm2 for D. The larger lesions at D may

  8. Effects of Mercury Chloride on the Cerebral Cortex of Adult Wistar Rats

    African Journals Online (AJOL)

    Mercury is among the heavy metals that have been reported to cause devastating health problem worldwide. The primary site of action of mercury chloride is the central nervous system. This study investigated the effect of mercury chloride on the cerebral cortex of adult wistar rats. Twenty-four (24) adult wistar rats were used ...

  9. Problem Reframing: Intelligence Professionals’ Role in Design

    Science.gov (United States)

    2010-04-01

    look at problem reframing requires an assessment of a people based system, according to Peter Checkland and John Poulter. During a deployment, the...military are members of a system and requires that they acts as practitioners. To assist in problem framing, Checkland and Poulter layout four conditions...the problem feasibly and accept input by some stakeholders. Problem reframing, takes Checkland and Poulter’s problem structuring after an initial

  10. Islamic Education Research Problem

    Directory of Open Access Journals (Sweden)

    Abdul Muthalib

    2012-04-01

    Full Text Available This paper will discuss Islamic educational studies that is reviewing how to find, limit and define problems and problem-solving concepts. The central question of this paper is to describe how to solve the problem in Islamic educational research. A researcher or educator who has the knowledge, expertise, or special interest on education for example is usually having a sensitivity to issues relating to educational research. In the research dimension of religious education, there are three types of problems, namely: Problems foundation, structural problems and operational issues. In doing research in Islamic education someone should understand research problem, limiting and formulating the problem, how to solve the problem, other problem relating to the point of research, and research approach.

  11. JIT-transportation problem and its algorithm

    Science.gov (United States)

    Bai, Guozhong; Gan, Xiao-Xiong

    2011-12-01

    This article introduces the (just-in-time) JIT-transportation problem, which requires that all demanded goods be shipped to their destinations on schedule, at a zero or minimal destination-storage cost. The JIT-transportation problem is a special goal programming problem with discrete constraints. This article provides a mathematical model for such a transportation problem and introduces the JIT solution, the deviation solution, the JIT deviation, etc. By introducing the B(λ)-problem, this article establishes the equivalence between the optimal solutions of the B(λ)-problem and the optimal solutions of the JIT-transportation problem, and then provides an algorithm for the JIT-transportation problems. This algorithm is proven mathematically and is also illustrated by an example.

  12. Effect of modafinil on learning performance and neocortical long-term potentiation in rats.

    Science.gov (United States)

    Burgos, Héctor; Castillo, Amparo; Flores, Osvaldo; Puentes, Gustavo; Morgan, Carlos; Gatica, Arnaldo; Cofré, Christian; Hernández, Alejandro; Laurido, Claudio; Constandil, Luis

    2010-10-30

    Modafinil is a novel wake-promoting agent whose effects on cognitive performance have begun to be addressed at both preclinical and clinical level. The present study was designed to investigate in rats the effects of chronic modafinil administration on cognitive performance by evaluating: (i) working and reference memories in an Olton 4×4 maze, and (ii) learning of a complex operant conditioning task in a Skinner box. In addition, the effect of modafinil on the ability of the rat frontal cortex to develop long-term potentiation (LTP) was also studied. Chronic modafinil did not significantly modify working memory errors but decreased long-term memory errors on the Olton 4×4 maze, meaning that the drug may have a favourable profile on performance of visuo-spatial tasks (typically, a hippocampus-dependent task) when chronically administered. On the other hand, chronic modafinil resulted in a marked decrease of successful responses in a complex operant conditioning learning, which means that repeated administration of the drug influences negatively problem-solving abilities when confronting the rat to a sequencing task (typically, a prefrontal cortex-dependent task). In addition, in vivo electrophysiology showed that modafinil resulted in impaired capacity of the rat prefrontal cortex to develop LTP following tetanization. It is concluded that modafinil can improve the performance of spatial tasks that depend almost exclusively on hippocampal functioning, but not the performance in tasks including a temporal factor where the prefrontal cortex plays an important role. The fact that modafinil together with preventing operant conditioning learning was also able to block LTP induction in the prefrontal cortex, suggests that the drug could interfere some critical component required for LTP can be developed, thereby altering neuroplastic capabilities of the prefrontal cortex. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. Electrofusion of mesenchymal stem cells and islet cells for diabetes therapy: a rat model.

    Directory of Open Access Journals (Sweden)

    Goichi Yanai

    Full Text Available Islet transplantation is a minimally invasive treatment for severe diabetes. However, it often requires multiple donors to accomplish insulin-independence and the long-term results are not yet satisfying. Therefore, novel ways to overcome these problems have been explored. Isolated islets are fragile and susceptible to pro-apoptotic factors and poorly proliferative. In contrast, mesenchymal stem cells (MSCs are highly proliferative, anti-apoptotic and pluripotent to differentiate toward various cell types, promote angiogenesis and modulate inflammation, thereby studied as an enhancer of islet function and engraftment. Electrofusion is an efficient method of cell fusion and nuclear reprogramming occurs in hybrid cells between different cell types. Therefore, we hypothesized that electrofusion between MSC and islet cells may yield robust islet cells for diabetes therapy. We establish a method of electrofusion between dispersed islet cells and MSCs in rats. The fusion cells maintained glucose-responsive insulin release for 20 days in vitro. Renal subcapsular transplantation of fusion cells prepared from suboptimal islet mass (1,000 islets that did not correct hyperglycemia even if co-transplanted with MSCs, caused slow but consistent lowering of blood glucose with significant weight gain within the observation period in streptozotocin-induced diabetic rats. In the fusion cells between rat islet cells and mouse MSCs, RT-PCR showed new expression of both rat MSC-related genes and mouse β-cell-related genes, indicating bidirectional reprogramming of both β-cell and MSCs nuclei. Moreover, decreased caspase3 expression and new expression of Ki-67 in the islet cell nuclei suggested alleviated apoptosis and gain of proliferative capability, respectively. These results show that electrofusion between MSCs and islet cells yield special cells with β-cell function and robustness of MSCs and seems feasible for novel therapeutic strategy for diabetes

  14. Effect of topically applied minoxidil on the survival of rat dorsal skin flap.

    Science.gov (United States)

    Gümüş, Nazım; Odemiş, Yusuf; Yılmaz, Sarper; Tuncer, Ersin

    2012-12-01

    Flap necrosis still is a challenging problem in reconstructive surgery that results in irreversible tissue loss. This study evaluated the effect of topically applied minoxidil on angiogenesis and survival of a caudally based dorsal rat skin flap. For this study, 24 male Wistar rats were randomly divided into three groups of eight each. A caudally based dorsal skin flap with the dimensions of 9 × 3 cm was raised. After elevation of the flaps, they were sutured back into their initial positions. In group 1 (control group), 1 ml of isotonic saline was applied topically to the flaps of all the animals for 14 days. In group 2, minoxidil solution was spread uniformly over the flap surface for 7 days after the flap elevation. In group 3, minoxidil solution was applied topically to the flap surface during a 14-day period. On day 7 after the flap elevation, the rats were killed. The average area of flap survival was determined for each rat. Subdermal vascular architecture and angiogenesis were evaluated under a light microscope after two full-thickness skin biopsy specimens had been obtained from the midline of the flaps. The lowest flap survival rate was observed in group 1, and no difference was observed between groups 1 and 2. Compared with groups 1 and 2, group 3 had a significantly increased percentage of flap survival (P minoxidil is vasodilation and that prolonged use before flap elevation leads to angiogenesis, increasing flap viability. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  15. The worldwide "wildfire" problem.

    Science.gov (United States)

    Gill, A Malcolm; Stephens, Scott L; Cary, Geoffrey J

    2013-03-01

    The worldwide "wildfire" problem is headlined by the loss of human lives and homes, but it applies generally to any adverse effects of unplanned fires, as events or regimes, on a wide range of environmental, social, and economic assets. The problem is complex and contingent, requiring continual attention to the changing circumstances of stakeholders, landscapes, and ecosystems; it occurs at a variety of temporal and spatial scales. Minimizing adverse outcomes involves controlling fires and fire regimes, increasing the resistance of assets to fires, locating or relocating assets away from the path of fires, and, as a probability of adverse impacts often remains, assisting recovery in the short-term while promoting the adaptation of societies in the long-term. There are short- and long-term aspects to each aspect of minimization. Controlling fires and fire regimes may involve fire suppression and fuel treatments such as prescribed burning or non-fire treatments but also addresses issues associated with unwanted fire starts like arson. Increasing the resistance of assets can mean addressing the design and construction materials of a house or the use of personal protective equipment. Locating or relocating assets can mean leaving an area about to be impacted by fire or choosing a suitable place to live; it can also mean the planning of land use. Assisting recovery and promoting adaptation can involve insuring assets and sharing responsibility for preparedness for an event. There is no single, simple, solution. Perverse outcomes can occur. The number of minimizing techniques used, and the breadth and depth of their application, depends on the geographic mix of asset types. Premises for policy consideration are presented.

  16. MATHEMATICAL PROBLEMS OF INTEGRATIVE CONTENTS

    Directory of Open Access Journals (Sweden)

    V. Kushnir

    2014-09-01

    Full Text Available The tasks of integrative content requires the use of knowledge and skills on various themes both one discipline and different disciplines. Mostly in the classroom (or in homework the tasks on the properties absorption of different concepts using different theories are considered. Thus knowledge within only one discipline is formed, knowledge of the narrow sense (one subject. Such knowledge is "prescriptional", we call it idealized. After all, it is far from models of the real professional problems and problems of life in general, in order to solve them it is necessary to apply knowledge and skills acquired in different themes of the same objects,life experience. Practical formation of integrative knowledge requires statement of the educational problems before the subjects of studying, the problems within the "narrow objectivity" can not be resolved at all, or such kind of solving is too difficult to solve, for example, the nature and the context of solving problems (scientific approaches to solving problems, creating mathematical models, methods for solving such models, means of solving, application of methods, analysis of the models solution and the right choice, the inspection of solutions, etc. will sink in the conglomeration of technical operations. The problems with integrative content are usually more complicated than the problems of "narrow objectivity." In our problems the index of such difficulty is the essence of educational content, which is disclosed in the previous paragraph. The problems solution proposed in this article requires knowledge of the structural geometry (circle construction, touching two or three laps: with analytic geometry (method of coordinates on the plane; the distance between two points on the coordinate plane; algebra (system drawing irrational equations, method for solving such system, the solution of the system, analysis of the results and the right choose of the desired solution for found criterion, testing

  17. The Markov moment problem and extremal problems

    CERN Document Server

    Kreĭn, M G; Louvish, D

    1977-01-01

    In this book, an extensive circle of questions originating in the classical work of P. L. Chebyshev and A. A. Markov is considered from the more modern point of view. It is shown how results and methods of the generalized moment problem are interlaced with various questions of the geometry of convex bodies, algebra, and function theory. From this standpoint, the structure of convex and conical hulls of curves is studied in detail and isoperimetric inequalities for convex hulls are established; a theory of orthogonal and quasiorthogonal polynomials is constructed; problems on limiting values of integrals and on least deviating functions (in various metrics) are generalized and solved; problems in approximation theory and interpolation and extrapolation in various function classes (analytic, absolutely monotone, almost periodic, etc.) are solved, as well as certain problems in optimal control of linear objects.

  18. THE QUALITY OF MATHEMATICAL PROBLEMS - EVALUATION AND SELF-EVALUATION

    Directory of Open Access Journals (Sweden)

    Patáková, Eva

    2013-09-01

    Full Text Available The research presented in the article consists of two parts. Firstly, opinions on mathematical problem quality are explored within four groups of participants (novices, specialists and experts in problem posing; high school students who never posed their own problems. Secondly, self-reflections written by the participants who have some experience in problem posing (novices, specialists and experts are explored and compared with the general view of problem quality received in the first part of the research. The more experienced problem posers have more requirements on problem quality (both as general requirements and within their own work on posing problems. There is a slight decrease in ability to notice important features of mathematical problem quality after the first experience in problem posing. Experts lay stress on mathematical features of the problem whilst novices and specialists more on problem – student interaction.

  19. Learning unlearnable problems with perceptrons

    Science.gov (United States)

    Watkin, Timothy L. H.; Rau, Albrecht

    1992-03-01

    We study how well perceptrons learn to solve problems for which there is no perfect answer (the usual case), taking as examples a rule with a threshold, a rule in which the answer is not a monotonic function of the overlap between question and teacher, and a rule with many teachers (a ``hard'' unlearnable problem). In general there is a tendency for first-order transitions, even using spherical perceptrons, as networks compromise between conflicting requirements. Some existing learning schemes fail completely-occasionally even finding the worst possible solution; others are more successful. High-temperature learning seems more satisfactory than zero-temperature algorithms and avoids ``overlearning'' and ``overfitting,'' but care must be taken to avoid ``trapping'' in spurious free-energy minima. For some rules examples alone are not enough to learn from, and some prior information is required.

  20. Mathematical problems in meteorological modelling

    CERN Document Server

    Csomós, Petra; Faragó, István; Horányi, András; Szépszó, Gabriella

    2016-01-01

    This book deals with mathematical problems arising in the context of meteorological modelling. It gathers and presents some of the most interesting and important issues from the interaction of mathematics and meteorology. It is unique in that it features contributions on topics like data assimilation, ensemble prediction, numerical methods, and transport modelling, from both mathematical and meteorological perspectives. The derivation and solution of all kinds of numerical prediction models require the application of results from various mathematical fields. The present volume is divided into three parts, moving from mathematical and numerical problems through air quality modelling, to advanced applications in data assimilation and probabilistic forecasting. The book arose from the workshop “Mathematical Problems in Meteorological Modelling” held in Budapest in May 2014 and organized by the ECMI Special Interest Group on Numerical Weather Prediction. Its main objective is to highlight the beauty of the de...

  1. Differential equations problem solver

    CERN Document Server

    Arterburn, David R

    2012-01-01

    REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and

  2. Prospects and problems of uranium enrichment

    International Nuclear Information System (INIS)

    Imai, Ryukichi

    1974-01-01

    The problem of uranium enrichment now concerns principally peaceful nuclear power generation. With the current oil crisis, energy resources assume unprecedented importance. However, the requirements for enriched uranium vary with the vicissitude of the world situation in nuclear power generation; the enterprise of uranium enrichment is related to economic aspect. The following matters are described: dimension of enrichment problem, political factors, changes in requirements, projects in each country, and strategy of enrichment in Japan. (Mori, K.)

  3. Current problems of nuclear arms: some options

    International Nuclear Information System (INIS)

    Bocharov, I.F.

    1992-01-01

    Possible solutions of certain problems of the soviet nuclear weapons resulting from spontaneously changing military-political situation and social-economical living conditions on geostrategical space of the former USSR are discussed. Reliable stabilization of military-political situation on the former USSR territory is required for solving the above problems, which in its turn will possibly require active efforts of the international community. The idea on creation the Committee on non-prolifiration by the UN Security Council is proposed

  4. Ising formulations of many NP problems

    OpenAIRE

    Lucas, Andrew

    2013-01-01

    We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.

  5. Ising formulations of many NP problems

    Directory of Open Access Journals (Sweden)

    Andrew eLucas

    2014-02-01

    Full Text Available We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.

  6. EARTHQUAKE RESEARCH PROBLEMS OF NUCLEAR POWER GENERATORS

    Energy Technology Data Exchange (ETDEWEB)

    Housner, G. W.; Hudson, D. E.

    1963-10-15

    Earthquake problems associated with the construction of nuclear power generators require a more extensive and a more precise knowledge of earthquake characteristics and the dynamic behavior of structures than was considered necessary for ordinary buildings. Economic considerations indicate the desirability of additional research on the problems of earthquakes and nuclear reactors. The nature of these earthquake-resistant design problems is discussed and programs of research are recommended. (auth)

  7. Radioactive wastes handling problems in Venezuela

    International Nuclear Information System (INIS)

    Ramirez, R.; Venegas, R.

    1984-07-01

    A brief description of the radioactive wastes problem in Venezuela is presented. The origins of the problem are shown in a squematic form. The requirements for its solution are divided into three parts: information system, control system, radioactive wastes hadling system. A questionnaire summarizing factors to be considered when looking for a solution to the problem in Venezuela is included, as well as conclusions and recomendations for further discussion

  8. Steam generators - problems and prognosis

    International Nuclear Information System (INIS)

    Tapping, R.L.

    1997-05-01

    Steam-generator problems, largely a consequence of corrosion and fouling, have resulted in increased inspection requirements and more regulatory attention to steam-generator integrity. In addition, utilities have had to develop steam-generator life-management strategies, including cleaning and replacement, to achieve design life. This paper summarizes the pertinent data to 1993/1994, and presents an overview of current steam-generator management practices. (author)

  9. Substantiating problems of quantum mechanics

    International Nuclear Information System (INIS)

    Gottlieb, J.

    1978-05-01

    Some basic problems, related to the spaces and the operators necessary to describe quantum-mechanical phenomena, are entered upon from a new axiomatic standpoint. Some generalizations are operated, required by convergence criteria, concerning the Fourier transform, the Fourier product and the equation of eigen-values. Physical arguments are brought to support such generalizations and an analysis in view of organizing the structure of the proposed spaces is undertaken. (author)

  10. Problems in quantum cosmology

    International Nuclear Information System (INIS)

    Amsterdamski, P.

    1986-01-01

    The standard cosmological model is reviewed and shown not to be self-sufficient in that it requires initial conditions most likely to be supplied by quantum cosmology. The possible approaches to the issue of initial conditions for cosmology are then discussed. In this thesis, the author considers three separate problems related to this issue. First, the possibility of inflation is investigated in detail by analyzing the evolution of metric perturbations and fluctuations in the expectation value of a scalar field prior to a phase transition; finite temperature effects are also included. Since the inhomogeneities were damped well before the onset of a phase transition. It is concluded that an inflation was possible. Next, the effective action of neutrino and photon fields is calculated for homogeneous spacetimes with small anisotropy; it is shown that quantum corrections to the action due to these fields influence the evolution of an early Universe in the Same way as do the analogous correction terms arising from a conformally invariant scalar which has been previously studied. Finally, the question of an early anisotropy is also discussed in a framework of Hartle-Hawking wave function of the Universe. A wave function of a Bianchi IX type Universe is calculated in a semiclassical approximation

  11. Development of transportation operations requirements

    International Nuclear Information System (INIS)

    Grady, S.T.; Best, R.E.; Danese, F.L.; Peterson, R.W.; Pope, R.B.

    1990-01-01

    Transport conditions at various utility sties vary dramatically in terms of characteristics at and near the site, requirements, administrative procedures, and other factors. Continuation of design efforts for the OCRWM transportation operations system requires that the operating requirements for the transportation system -- quantity of fuel per unit time per site -- be identified so that the effect the variations have on the system can be accommodated. The approach outlined in this paper provides for an identification of specific sites, evaluation of shipment capabilities at each site, and integration of the sites into multi-site shipping campaigns to scope the logistics management problem for the transportation operations system. 1 fig., 1 tab

  12. Side Effects: Sleep Problems

    Science.gov (United States)

    Sleep problems are a common side effect during cancer treatment. Learn how a polysomnogram can assess sleep problems. Learn about the benefits of managing sleep disorders in men and women with cancer.

  13. The internal percolation problem

    International Nuclear Information System (INIS)

    Bezsudnov, I.V.; Snarskii, A.A.

    2010-01-01

    The internal percolation problem (IP) as a new type of the percolation problem is introduced and investigated. In spite of the usual (or external) percolation problem (EP) when the percolation current flows from the top to the bottom of the system, in IP case the voltage is applied through bars which are present in the hole located within the system. The EP problem has two major parameters: M-size of the system and a 0 -size of inclusions, bond size, etc. The IP problem holds one parameter more: size of the hole L. Numerical simulation shows that the critical indexes of conductance for the IP problem are very close to those in the EP problem. On the contrary, the indexes of the relative spectral noise density of 1/f noise and higher moments differ from those in the EP problem. The basics of these facts is discussed.

  14. Challenging problems in algebra

    CERN Document Server

    Posamentier, Alfred S

    1996-01-01

    Over 300 unusual problems, ranging from easy to difficult, involving equations and inequalities, Diophantine equations, number theory, quadratic equations, logarithms, more. Detailed solutions, as well as brief answers, for all problems are provided.

  15. Study the Problem.

    Science.gov (United States)

    Choate, Joyce S.

    1990-01-01

    The initial step of a strategic process for solving mathematical problems, "studying the question," is discussed. A lesson plan for teaching students to identify and revise arithmetic problems is presented, involving directed instruction and supervised practice. (JDD)

  16. Individually reared rats

    International Nuclear Information System (INIS)

    Kraeuchi, K.; Gentsch, C.; Feer, H.

    1981-01-01

    The influence of social isolation in rats on postsynaptic alpha 1 - and beta-adrenergic receptors, on the cAMP generating system and on the presynaptic uptake mechanism in the central noradrenergic system was examined in different brain regions. Rearing rats in isolation from the 19th day of life for 12 weeks leads in all regions to a general tendency for a reduction in 3 H-DHA binding, to an enhanced 3 H-WB4101 binding and to a decreased responsiveness of the noradrenaline sensitive cAMP generating system. These changes reach significance only in the pons-medulla-thallamusregion. Isolated rats showed an increased synaptosomal uptake of noradrenaline, most pronounced and significant in the hypothalamus. Our data provide further support for a disturbance in central noradrenergic function in isolated rats. (author)

  17. Locomotor damage in rats after x-irradiation in Utero

    International Nuclear Information System (INIS)

    Mullenix, P.; Norton, S.; Culver, B.

    1975-01-01

    Alterations in gait were found in rats after whole-body irradiation with 125 R on day 14, 15, and 16 of gestation. No effects on locomotion were detected after irradiation on day 17 with 125 R or after irradiation on day 14 with 50 R. A technique was set up for quantitative evaluation of locomotion based on a modification of other methods. Walking patterns of irradiated rats were recorded, when they were adults, by requiring them to walk up a 10 0 incline through a corridor after their feet had been dipped in ink. Rats irradiated on gestational day 14 had an in-phase, hopping gait with the sine of the angle between the hind feet and the direction of progression over 0.9. Rats irradiated on gestational days 15 and 16 had an alternating, waddling gait with wider stance and broader angle than control rats. Histologic examination of serial sections of the brains of these rats showed that the 14-day rats lacked all telencephalic commissures except for a few fibers which crossed in some rats. There was a progressive improvement in the condition of the anterior and ventral hippocampal commissures up to day 17, but the corpus callosum and doral hippocampal commissure were lacking or markedly reduced in all day 17 rats. No animals showed damage to the mesencephalic posterior commissure. Since rats which used the in-phase mode of locomotion were never observed to use alternating gait, the possible causal relationship of the commissural damage to the altered locomotor patterns was considered. In view of the restricted period of damage found for the anterior and ventral hippocampal commissures and the restriction of altered locomotion to damage in the same period, primary involvement of the corpus callosum and dorsal hippocampal commissure could be excluded, but a possible role for the other telencephalic commissures remained

  18. Cosmological constant problem

    International Nuclear Information System (INIS)

    Weinberg, S.

    1989-01-01

    Cosmological constant problem is discussed. History of the problem is briefly considered. Five different approaches to solution of the problem are described: supersymmetry, supergravity, superstring; anthropic approach; mechamism of lagrangian alignment; modification of gravitation theory and quantum cosmology. It is noted that approach, based on quantum cosmology is the most promising one

  19. The Complete Problem Solver.

    Science.gov (United States)

    Hayes, John R.

    This book, designed for a college course on general problem-solving skills, focuses on skills that can be used by anyone in solving problems that occur in everyday life. Part I considers theory and practice: understanding problems, search, and protocol analysis. Part II discusses memory and knowledge acquisition: the structure of human memory,…

  20. The rational complementarity problem

    NARCIS (Netherlands)

    Heemels, W.P.M.H.; Schumacher, J.M.; Weiland, S.

    1999-01-01

    An extension of the linear complementarity problem (LCP) of mathematical programming is the so-called rational complementarity problem (RCP). This problem occurs if complementarity conditions are imposed on input and output variables of linear dynamical input/state/output systems. The resulting

  1. The triangle scheduling problem

    NARCIS (Netherlands)

    Dürr, Christoph; Hanzálek, Zdeněk; Konrad, Christian; Seddik, Yasmina; Sitters, R.A.; Vásquez, Óscar C.; Woeginger, Gerhard

    2017-01-01

    This paper introduces a novel scheduling problem, where jobs occupy a triangular shape on the time line. This problem is motivated by scheduling jobs with different criticality levels. A measure is introduced, namely the binary tree ratio. It is shown that the Greedy algorithm solves the problem to

  2. Classifying IS Project Problems

    DEFF Research Database (Denmark)

    Munk-Madsen, Andreas

    2006-01-01

    The literature contains many lists of IS project problems, often in the form of risk factors. The problems sometimes appear unordered and overlapping, which reduces their usefulness to practitioners as well as theoreticians. This paper proposes a list of criteria for formulating project problems...

  3. Inverse problems of geophysics

    International Nuclear Information System (INIS)

    Yanovskaya, T.B.

    2003-07-01

    This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

  4. Capturing security requirements for software systems.

    Science.gov (United States)

    El-Hadary, Hassan; El-Kassas, Sherif

    2014-07-01

    Security is often an afterthought during software development. Realizing security early, especially in the requirement phase, is important so that security problems can be tackled early enough before going further in the process and avoid rework. A more effective approach for security requirement engineering is needed to provide a more systematic way for eliciting adequate security requirements. This paper proposes a methodology for security requirement elicitation based on problem frames. The methodology aims at early integration of security with software development. The main goal of the methodology is to assist developers elicit adequate security requirements in a more systematic way during the requirement engineering process. A security catalog, based on the problem frames, is constructed in order to help identifying security requirements with the aid of previous security knowledge. Abuse frames are used to model threats while security problem frames are used to model security requirements. We have made use of evaluation criteria to evaluate the resulting security requirements concentrating on conflicts identification among requirements. We have shown that more complete security requirements can be elicited by such methodology in addition to the assistance offered to developers to elicit security requirements in a more systematic way.

  5. Capturing security requirements for software systems

    Directory of Open Access Journals (Sweden)

    Hassan El-Hadary

    2014-07-01

    Full Text Available Security is often an afterthought during software development. Realizing security early, especially in the requirement phase, is important so that security problems can be tackled early enough before going further in the process and avoid rework. A more effective approach for security requirement engineering is needed to provide a more systematic way for eliciting adequate security requirements. This paper proposes a methodology for security requirement elicitation based on problem frames. The methodology aims at early integration of security with software development. The main goal of the methodology is to assist developers elicit adequate security requirements in a more systematic way during the requirement engineering process. A security catalog, based on the problem frames, is constructed in order to help identifying security requirements with the aid of previous security knowledge. Abuse frames are used to model threats while security problem frames are used to model security requirements. We have made use of evaluation criteria to evaluate the resulting security requirements concentrating on conflicts identification among requirements. We have shown that more complete security requirements can be elicited by such methodology in addition to the assistance offered to developers to elicit security requirements in a more systematic way.

  6. Gamified Requirements Engineering: Model and Experimentation

    NARCIS (Netherlands)

    Lombriser, Philipp; Dalpiaz, Fabiano; Lucassen, Garm; Brinkkemper, Sjaak

    2016-01-01

    [Context & Motivation] Engaging stakeholders in requirements engineering (RE) influences the quality of the requirements and ultimately of the system to-be. Unfortunately, stakeholder engagement is often insufficient, leading to too few, low-quality requirements. [Question/problem] We aim to

  7. Capturing security requirements for software systems

    Science.gov (United States)

    El-Hadary, Hassan; El-Kassas, Sherif

    2014-01-01

    Security is often an afterthought during software development. Realizing security early, especially in the requirement phase, is important so that security problems can be tackled early enough before going further in the process and avoid rework. A more effective approach for security requirement engineering is needed to provide a more systematic way for eliciting adequate security requirements. This paper proposes a methodology for security requirement elicitation based on problem frames. The methodology aims at early integration of security with software development. The main goal of the methodology is to assist developers elicit adequate security requirements in a more systematic way during the requirement engineering process. A security catalog, based on the problem frames, is constructed in order to help identifying security requirements with the aid of previous security knowledge. Abuse frames are used to model threats while security problem frames are used to model security requirements. We have made use of evaluation criteria to evaluate the resulting security requirements concentrating on conflicts identification among requirements. We have shown that more complete security requirements can be elicited by such methodology in addition to the assistance offered to developers to elicit security requirements in a more systematic way. PMID:25685514

  8. The Home Care Crew Scheduling Problem:

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Justesen, Tor; Dohn, Anders

    In the Home Care Crew Scheduling Problem a staff of caretakers has to be assigned a number of visits to patients' homes, such that the overall service level is maximised. The problem is a generalisation of the vehicle routing problem with time windows. Required travel time between visits and time...... preference constraints. The algorithm is tested both on real-life problem instances and on generated test instances inspired by realistic settings. The use of the specialised branching scheme on real-life problems is novel. The visit clustering decreases run times significantly, and only gives a loss...... windows of the visits must be respected. The challenge when assigning visits to caretakers lies in the existence of soft preference constraints and in temporal dependencies between the start times of visits. We model the problem as a set partitioning problem with side constraints and develop an exact...

  9. Problem neurology residents: a national survey.

    Science.gov (United States)

    Tabby, David S; Majeed, Muhammed H; Schwartzman, Robert J

    2011-06-14

    Problem residents are found across most medical specialties at a prevalence of about 10%. This study was designed to explore the prevalence and causes of problem neurology residents and to compare neurology programs' responses and outcomes. Directors of 126 US neurology residency programs were sent an electronic survey. We collected data on demographics, first and all "identifiers" of problem residents, and year of training in which the problem was found. We asked about observable signs, etiology, and who performed remediation. We asked what resources were used and what outcomes occurred. Ninety-five program directors completed surveys (75% response rate). Almost all neurology programs have problem residents (81%). Age, sex, marital status, being a US native, or attending a US medical school had no effect on problem status. Being a parent carried a lower likelihood of problems (32%). Most commonly the problem is acted on during the first year of training. Faculty members without defined educational roles were the most frequent first identifiers. Program directors were the most common remediators. The most common remediation techniques were increasing supervision and assigning a faculty mentor. Graduate medical education office and psychiatric or psychological counseling services were most often used. Eleven percent of problem residents required a program for impaired physicians and 14% required a leave of absence. Sixteen percent were dismissed from their programs. The prevalence of problem residents in neurology is similar to other disciplines, and various resources are available to remediate them.

  10. SOFG: Standards requirements

    International Nuclear Information System (INIS)

    Gerganov, T.; Grigorov, S.; Kozhukharov, V.; Brashkova, N.

    2005-01-01

    It is well-known that Solid Oxide Fuel Cells will have industrial application in the nearest future. In this context, the problem of SOFC materials and SOFC systems standardization is of high level of priority. In the present study the attention is focused on the methods for physical and chemical characterization of the materials for SOFC components fabrication and about requirements on single SOFC cells tests. The status of the CEN, ISO, ASTM (ANSI, ASSN) and JIS class of standards has been verified. Standards regarding the test methods for physical-chemical characterization of vitreous materials (as sealing SOFC component), ceramic materials (as electrodes and electrolyte components, including alternative materials used) and metallic materials (interconnect components) are subject of overview. It is established that electrical, mechanical, surface and interfacial phenomena, chemical durability and thermal corrosion behaviour are the key areas for standardization of the materials for SOFC components

  11. Phase Transitions in Planning Problems: Design and Analysis of Parameterized Families of Hard Planning Problems

    Science.gov (United States)

    Hen, Itay; Rieffel, Eleanor G.; Do, Minh; Venturelli, Davide

    2014-01-01

    problems to QUBOs, the form of input required for a quantum annealing machine such as the D-Wave II.

  12. Effect of acclimation to caging on nephrotoxic response of rats to uranium.

    Science.gov (United States)

    Damon, E G; Eidson, A F; Hobbs, C H; Hahn, F F

    1986-02-01

    Animal studies of the toxicity and metabolism of radionuclides and chemicals often require housing of rats in metabolism cages for excreta collection. Response of rats to toxic substances may be affected by environmental factors such as the type of cage used. Dose-response studies were conducted to assess the effects of two types of cages on the nephrotoxic response of rats to uranium from implanted refined uranium ore (yellowcake). The LD50/21 days was 6 mg of uranium ore per kilogram body weight (6 mg U/kg). The 95% confidence limit (C.L.) was 3-8 mg U/kg for rats housed in metabolism cages beginning on the day of implantation (naive rats). However, for rats housed in metabolism cages for 21 days before implantation (acclimated rats) the LD50/21 days was 360 mg U/kg (95% C.L. = 220-650 mg U/kg), which was the same value obtained for rats housed continuously in polycarbonate cages. This significant difference (P less than 0.01) in response of naive rats compared to response of acclimated rats appeared related to a significantly lower water consumption by the naive rats.

  13. A defect in the inflammation-primed macrophage-activation cascade in osteopetrotic rats.

    Science.gov (United States)

    Yamamoto, N; Lindsay, D D; Naraparaju, V R; Ireland, R A; Popoff, S N

    1994-05-15

    Macrophages were activated by administration of lysophosphatidylcholine (lyso-Pc) or dodecylglycerol (DDG) to wild-type rats but not in osteopetrotic (op) mutant rats. In vitro treatment of wild-type rat peritoneal cells with lyso-Pc or DDG efficiently activated macrophages whereas treatment of op mutant rat peritoneal cells with lyso-Pc or DDG did not activate macrophages. The inflammation-primed macrophage activation cascade in rats requires participation of B lymphocytes and vitamin D binding protein (DBP). Lyso-Pc-inducible beta-galactosidase of wild-type rat B lymphocytes can convert DBP to the macrophage-activating factor (MAF), whereas B lymphocytes of the op mutant rats were shown to be deficient in lyso-Pc-inducible beta-galactosidase. DBP is conserved among mammalian species. Treatment of human DBP (Gc1 protein) with commercial glycosidases yields an extremely high titrated MAF as assayed on mouse and rat macrophages. Because the enzymatically generated MAF (GcMAF) bypasses the role of lymphocytes in macrophage activation, the op mutant rat macrophages were efficiently activated by administration of a small quantity (100 pg/rat) of GcMAF. Likewise, in vitro treatment of op rat peritoneal cells with as little as 40 pg GcMAF/ml activated macrophages.

  14. Optimization of reagent concentration for radioiodination of rat C-peptide II in development of radioimmunoassay procedure for rats

    Directory of Open Access Journals (Sweden)

    B R Manupriya

    2018-01-01

    Full Text Available Rat C-peptide is a polypeptide molecule made up of 31 amino acids and secreted from pancreas into circulation in two isoforms I and II. Quantification of rat C-peptide II in rat serum is important as it is directly related to the diagnosis of carbohydrate metabolism abnormalities, pancreatic performance analysis, monitoring of hypoglycemia, and diabetes-related illness in rat model. The aim of the present work is to develop a tracer by chloramine-T method for radioimmunoassay (RIA procedure and to determine the optimum amount of chloramine-T required for the preparation of stable radioiodinated product with a specific activity of around 24.97 MBq/μg, corresponding to 1 125I atom per molecule of the peptide. Tyrosylated rat C-peptide II was selected for the radioiodination procedure as rat C-peptide II does not contain either tyrosine or histidine which is mandatory for the incorporation of 125I atom to the rat C-peptide II. Tyrosylated rat C-peptide II was subjected to radioiodination by chloramine-T method with different concentrations of chloramine-T and sodium metabisulfite (MBS to obtain a stable radiolabeled compound. Optimized reaction conditions relating to the concentration of chloramine-T (10 μg and MBS (20 μg yielded a stable 125I-rat C-peptide II with specific activity of 21.01 MBq/μg corresponding to 0.84 125I atoms per molecule of the peptide. Preparation of high integrity tracer of rat C-peptide II was achieved by combining one molecule of oxidant (chloramine-T and two molecule of reductant (MBS.

  15. The NLC Software Requirements Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Shoaee, Hamid

    2002-08-20

    We describe the software requirements and development methodology developed for the NLC control system. Given the longevity of that project, and the likely geographical distribution of the collaborating engineers, the planned requirements management process is somewhat more formal than the norm in high energy physics projects. The short term goals of the requirements process are to accurately estimate costs, to decompose the problem, and to determine likely technologies. The long term goal is to enable a smooth transition from high level functional requirements to specific subsystem and component requirements for individual programmers, and to support distributed development. The methodology covers both ends of that life cycle. It covers both the analytical and documentary tools for software engineering, and project management support. This paper introduces the methodology, which is fully described in [1].

  16. On conjugate points and the Leitmann equivalent problem approach

    NARCIS (Netherlands)

    Wagener, F.O.O.

    2009-01-01

    This article extends the Leitmann equivalence method to a class of problems featuring conjugate points. The class is characterised by the requirement that the set of indifference points of a given problem forms a finite stratification.

  17. Encoding changes in orbitofrontal cortex in reversal-impaired aged rats.

    Science.gov (United States)

    Schoenbaum, Geoffrey; Setlow, Barry; Saddoris, Michael P; Gallagher, Michela

    2006-03-01

    Previous work in rats and primates has shown that normal aging can be associated with a decline in cognitive flexibility mediated by prefrontal circuits. For example, aged rats are impaired in rapid reversal learning, which in young rats depends critically on the orbitofrontal cortex. To assess whether aging-related reversal impairments reflect orbitofrontal dysfunction, we identified aged rats with reversal learning deficits and then recorded single units as these rats, along with unimpaired aged cohorts and young control rats, learned and reversed a series of odor discrimination problems. We found that the flexibility of neural correlates in orbitofrontal cortex was markedly diminished in aged rats characterized as reversal-impaired in initial training. In particular, although many cue-selective neurons in young and aged-unimpaired rats reversed odor preference when the odor-outcome associations were reversed, cue-selective neurons in reversal-impaired aged rats did not. In addition, outcome-expectant neurons in aged-impaired rats failed to become active during cue sampling after learning. These altered features of neural encoding could provide a basis for cognitive inflexibility associated with normal aging.

  18. Beta Adrenergic Regulation of Intrapulmonary Arteriovenous Anastomoses in Intact Rat and Isolated Rat Lungs

    Directory of Open Access Journals (Sweden)

    Melissa L. Bates

    2017-04-01

    Full Text Available Intrapulmonary arteriovenous anastomoses (IPAVA allow large diameter particles of venous origin to bypass the pulmonary capillary bed and embolize the systemic arterial circulation. IPAVA have been routinely observed in healthy humans with exercise, hypoxia, and catecholamine infusion, but the mechanism by which they are recruited is not well-defined. We hypothesized that beta-adrenergic receptor stimulation recruits IPAVA and that receptor blockade would limit hypoxia-induced IPAVA recruitment. To test our hypothesis, we evaluated the transpulmonary passage of microspheres in intact rats and isolated rats lung infused with the beta-adrenergic receptor agonist isoproterenol. We also evaluated IPAVA recruitment in intact rats with hypoxia and the beta-adrenergic receptor blocker propranolol. We found that IPAVA are recruited in the intact rat by isoproterenol and their recruitment by hypoxia can be minimized by propranolol, suggesting a role for the adrenergic system in the recruitment of IPAVA by hypoxia. IPAVA recruitment is completely abolished by ventilation with 100% oxygen. Isoproterenol also recruits IPAVA in isolated rat lungs. The fact that isoproterenol can recruit IPAVA in isolated lungs, without increased pulmonary flow, suggests that elevated cardiac output is not required for IPAVA recruitment.

  19. Comparison of rat and rabbit embryo-fetal developmental ...

    Science.gov (United States)

    Regulatory non-clinical safety testing of human pharmaceutical compounds typically requires embryo fetal developmental toxicity (EFDT) testing in two species, (one rodent and one non-rodent, usually the rat and the rabbit). The question has been raised whether under some conditions EFDT testing could be limited to one species, or whether the need for testing in a second species could be decided on a case by case basis. As part of an RIVM/CBG-MEB/HESI/US EPA consortium initiative, we built and queried a database of 379 EFDT studies conducted for marketed and non-marketed pharmaceutical compounds. The animal models (rat and rabbit) were assessed for their potential for adverse developmental and maternal outcomes. The database was analyzed for the prevalence of EFDT incidence and the nature and severity of adverse findings in the two species. Some manifestation of EFDT in either one or both species (rat and rabbit) was demonstrated for 282 compounds (74%), and EFDT was detected in only one species (rat or rabbit) in almost a third (31%, 118 compounds), with approximately 58% rat and 42% rabbit studies identifying an EFDT signal among the 379 compounds tested. For 24 compounds (6%), fetal malformations were observed in one species (rat or rabbit) in the absence of any EFDT in the second species. In general, growth retardation, fetal variations, and malformations were more prominent in the rat, whereas embryo-fetal death was observed more often in the rabbit. Discor

  20. Environmental problem-solving: Psychosocial factors

    Science.gov (United States)

    Miller, Alan

    1982-11-01

    This is a study of individual differences in environmental problem-solving, the probable roots of these differences, and their implications for the education of resource professionals. A group of student Resource Managers were required to elaborate their conception of a complex resource issue (Spruce Budworm management) and to generate some ideas on management policy. Of particular interest was the way in which subjects dealt with the psychosocial aspects of the problem. A structural and content analysis of responses indicated a predominance of relatively compartmentalized styles, a technological orientation, and a tendency to ignore psychosocial issues. A relationship between problem-solving behavior and personal (psychosocial) style was established which, in the context of other evidence, suggests that problem-solving behavior is influenced by more deep seated personality factors. The educational implication drawn was that problem-solving cannot be viewed simply as an intellectual-technical activity but one that involves, and requires the education of, the whole person.

  1. Requirements Analysis in the Value Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Conner, Alison Marie

    2001-05-01

    The Value Methodology (VM) study brings together a multidisciplinary team of people who own the problem and have the expertise to identify and solve it. With the varied backgrounds and experiences the team brings to the study, come different perspectives on the problem and the requirements of the project. A requirements analysis step can be added to the Information and Function Analysis Phases of a VM study to validate whether the functions being performed are required, either regulatory or customer prescribed. This paper will provide insight to the level of rigor applied to a requirements analysis step and give some examples of tools and techniques utilized to ease the management of the requirements and functions those requirements support for highly complex problems.

  2. Section 4: Requirements Intertwining

    Science.gov (United States)

    Loucopoulos, Pericles

    Business analysts are being asked to develop increasingly complex and varied business systems that need to cater to the changing and dynamic market conditions of the new economy. This is particularly acute in today’s turbulent business environment where powerful forces such as deregulation, globalisation, mergers, advances in information and telecommunications technologies, and increasing education of people provide opportunities for organising work in ways that have never before been possible. Enterprises attempt to create wealth either by getting better at improving their products and services or by harnessing creativity and human-centred management to create innovative solutions. In these business settings, requirements become critical in bridging system solutions to organisational and societal problems. They intertwine organisational, social, cognitive, and implementation considerations and they can provide unique insights to change in systems and their business context. Such design situations often involve multiple stakeholders from different participating organisations, subcontractors, divisions, etc., who may have a diversity of expertise, come from different organisational cultures and often have competing goals. The success or failure of many projects depends, to a large extent, on understanding the contextual setting of requirements and their interaction amongst a diverse population of stakeholders.

  3. Next Generation Microbiology Requirements

    Science.gov (United States)

    Ott, C. M.; Oubre, C. M.; Elliott, T. F.; Castro, V. A.; Pierson, D. L.

    2012-01-01

    As humans continue to explore deep into space, microorganisms will travel with them. The primary means to mitigate the risk of infectious disease are a combination of prudent spacecraft design and rigorous operational controls. The effectiveness of these methods are evaluated by microbiological monitoring of spacecraft, food, water, and the crew that is performed preflight, in-flight, and post-flight. Current NASA requirements associated with microbiological monitoring are based on culture-based methodology where microorganisms are grown on a semi-solid growth medium and enumerated. Subsequent identification of the organisms requires specialized labor and large equipment, which historically has been performed on Earth. Requirements that rely strictly on culture-based units limit the use of non-culture based monitoring technology. Specifically, the culture-based "measurement criteria" are Colony Forming Units (CFU, representing the growth of one microorganism at a single location on the agar medium) per a given volume, area, or sample size. As the CFU unit by definition is culture-based, these requirements limit alternative technologies for spaceflight applications. As spaceflight missions such as those to Mars extend further into space, culture-based technology will become difficult to implement due to the (a) limited shelf life of the culture media, (b) mass/volume necessary to carry these consumables, and (c) problems associated with the production of biohazardous material in the habitable volume of the spacecraft. In addition, an extensive amount of new knowledge has been obtained during the Space Shuttle, NASA-Mir, and International Space Station Programs, which gave direction for new or modified microbial control requirements for vehicle design and mission operations. The goal of this task is to develop and recommend a new set of requirements for vehicle design and mission operations, including microbiological monitoring, based upon "lessons learned" and new

  4. Requirements Engineering for Software Integrity and Safety

    Science.gov (United States)

    Leveson, Nancy G.

    2002-01-01

    Requirements flaws are the most common cause of errors and software-related accidents in operational software. Most aerospace firms list requirements as one of their most important outstanding software development problems and all of the recent, NASA spacecraft losses related to software (including the highly publicized Mars Program failures) can be traced to requirements flaws. In light of these facts, it is surprising that relatively little research is devoted to requirements in contrast with other software engineering topics. The research proposed built on our previous work. including both criteria for determining whether a requirements specification is acceptably complete and a new approach to structuring system specifications called Intent Specifications. This grant was to fund basic research on how these ideas could be extended to leverage innovative approaches to the problems of (1) reducing the impact of changing requirements, (2) finding requirements specification flaws early through formal and informal analysis, and (3) avoiding common flaws entirely through appropriate requirements specification language design.

  5. CHASM Challenge Problem: Lagrangian Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, R [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keasler, J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gokhale, M [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-09-10

    Computer simulations of many science and engineering problems require modeling the equations of hydrodynamics which describe the motion of materials relative to each other induced by various forces. Many important DoD simulation problems involve complex multi-material systems that undergo large deformations. Examples include the analysis of armor defense, penetration mechanics, blast effects, structural integrity, and conventional munitions such as shaped charges and explosively formed projectiles. Indeed, the original motivation for developing codes that solve the equations of hydrodynamics, herein referred to as “hydrocodes”, was to solve problems with defense applications. The FY2010 Requirements Analysis Report issued by the DoD High Performance Computing Modernization Program (HPCMP) Office shows that a major portion of DoD HPC activities involves hydrocodes [HPCMP2010]. The report surveyed 496 projects across the Services and various Agencies, representing 4,050 HPCMP users at more than 125 locations, including government, contractors, and academia, and grouped each project into one of ten categories.

  6. Semidefinite linear complementarity problems

    International Nuclear Information System (INIS)

    Eckhardt, U.

    1978-04-01

    Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de

  7. Matrix interdiction problem

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

    2010-01-01

    In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.

  8. Creativity for Problem Solvers

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    2009-01-01

    This paper presents some modern and interdisciplinary concepts about creativity and creative processes specially related to problem solving. Central publications related to the theme are briefly reviewed. Creative tools and approaches suitable to support problem solving are also presented. Finally......, the paper outlines the author’s experiences using creative tools and approaches to: Facilitation of problem solving processes, strategy development in organisations, design of optimisation systems for large scale and complex logistic systems, and creative design of software optimisation for complex non...

  9. Perturbed asymptotically linear problems

    OpenAIRE

    Bartolo, R.; Candela, A. M.; Salvatore, A.

    2012-01-01

    The aim of this paper is investigating the existence of solutions of some semilinear elliptic problems on open bounded domains when the nonlinearity is subcritical and asymptotically linear at infinity and there is a perturbation term which is just continuous. Also in the case when the problem has not a variational structure, suitable procedures and estimates allow us to prove that the number of distinct crtitical levels of the functional associated to the unperturbed problem is "stable" unde...

  10. The stochastic goodwill problem

    OpenAIRE

    Marinelli, Carlo

    2003-01-01

    Stochastic control problems related to optimal advertising under uncertainty are considered. In particular, we determine the optimal strategies for the problem of maximizing the utility of goodwill at launch time and minimizing the disutility of a stream of advertising costs that extends until the launch time for some classes of stochastic perturbations of the classical Nerlove-Arrow dynamics. We also consider some generalizations such as problems with constrained budget and with discretionar...

  11. The pear thrips problem

    Science.gov (United States)

    Bruce L. Parker

    1991-01-01

    As entomologists, we sometimes like to think of an insect pest problem as simply a problem with an insect and its host. Our jobs would be much easier if that were the case, but of course, it is never that simple. There are many other factors besides the insect, and each one must be fully considered to understand the problem and develop effective management solutions....

  12. THE PROBLEM OF SUPPLIER

    OpenAIRE

    Raffo Lecca, Eduardo

    2014-01-01

    This is a famous problem from the annals of literature in operations research. G. Dantzig in [1] refers to W.W. Jacobs with his paper "The Caterer Problem" Nav. Log Res. Quart. 1 1954; as well as Gaddum, Hoffman and Sokolowsky "On the Solution of the Caterer Problem" Naval Res Logist. Quart., Vol.1, No. 3, september, 1954, and William Prager "On the Caterer Problem" of Management Sci, Vol 3, No. 1 october 1956 and Management Sci, Vol 3, No. 2 january 1957. Subsequently both G. Hadley presents...

  13. The Problem of Evil

    OpenAIRE

    Araki,Naoki

    2018-01-01

    The Problem of Evil has been discussed as one of the major problems in monotheism. “Why does Almighty God allow evil to exist?” Various solutions to this problem have been proposed, including the Free Will Defence. But none of them is convincing. The Problem of Evil has an assumption, which is that God exists. One of the proofs of God’s existence is René Descartes’s Ontological Argument. But none of them is persuasive. Every logic has its own assumption, which needs to be verified. So this pr...

  14. Numerical problems in physics

    CERN Document Server

    Singh, Devraj

    2015-01-01

    Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

  15. Simon on problem solving

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul

    2006-01-01

    as a general approach to problem solving. We apply these Simonian ideas to organisational issues, specifically new organisational forms. Specifically, Simonian ideas allow us to develop a morphology of new organisational forms and to point to some design problems that characterise these forms.......Two of Herbert Simon's best-known papers are 'The Architecture of Complexity' and 'The Structure of Ill-Structured Problems.' We discuss the neglected links between these two papers, highlighting the role of decomposition in the context of problems on which constraints have been imposed...

  16. On Euler's problem

    International Nuclear Information System (INIS)

    Egorov, Yurii V

    2013-01-01

    We consider the classical problem on the tallest column which was posed by Euler in 1757. Bernoulli-Euler theory serves today as the basis for the design of high buildings. This problem is reduced to the problem of finding the potential for the Sturm-Liouville equation corresponding to the maximum of the first eigenvalue. The problem has been studied by many mathematicians but we give the first rigorous proof of the existence and uniqueness of the optimal column and we give new formulae which let us find it. Our method is based on a new approach consisting in the study of critical points of a related nonlinear functional. Bibliography: 6 titles.

  17. Shielding benchmark problems, (2)

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Shin, Kazuo; Tada, Keiko.

    1980-02-01

    Shielding benchmark problems prepared by Working Group of Assessment of Shielding Experiments in the Research Committee on Shielding Design in the Atomic Energy Society of Japan were compiled by Shielding Laboratory in Japan Atomic Energy Research Institute. Fourteen shielding benchmark problems are presented newly in addition to twenty-one problems proposed already, for evaluating the calculational algorithm and accuracy of computer codes based on discrete ordinates method and Monte Carlo method and for evaluating the nuclear data used in codes. The present benchmark problems are principally for investigating the backscattering and the streaming of neutrons and gamma rays in two- and three-dimensional configurations. (author)

  18. Art as metontological problem

    Directory of Open Access Journals (Sweden)

    Radovanović Saša Ž.

    2014-01-01

    Full Text Available The author explains the link between fundamental ontology and metontology in Heidegger's thought. In this context, he raises the question about art as a metontological problem. Then he goes to show that the problem of metontology stems from imanent transformation of fundamental ontology. In this sense, two aspects of the problem of existence assume relevance, namely, universality and radicalism. He draws the conclusion that metontology and art as its problem, as opposed to fundamental ontology, were not integrated into Heidegger's later thought.

  19. Combinatorial problems and exercises

    CERN Document Server

    Lovász, László

    2007-01-01

    The main purpose of this book is to provide help in learning existing techniques in combinatorics. The most effective way of learning such techniques is to solve exercises and problems. This book presents all the material in the form of problems and series of problems (apart from some general comments at the beginning of each chapter). In the second part, a hint is given for each exercise, which contains the main idea necessary for the solution, but allows the reader to practice the techniques by completing the proof. In the third part, a full solution is provided for each problem. This book w

  20. Rapid quality assurance with Requirements Smells

    OpenAIRE

    Femmer, H.; Fernández, D. Méndez; Wagner, S.; Eder, S.

    2016-01-01

    Bad requirements quality can cause expensive consequences during the software development lifecycle, especially if iterations are long and feedback comes late. %-- the faster a problem is found, the cheaper it is to fix. This makes explicit the need of a lightweight detection mechanism of requirements quality violations. We aim at a light-weight static requirements analysis approach that allows for rapid checks immediately when requirements are written down. We transfer the concept of code sm...

  1. Solving the wrong hierarchy problem

    International Nuclear Information System (INIS)

    Blinov, Nikita; Hook, Anson

    2016-01-01

    Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and Z_2-symmetric theories where the Standard Model Higgs potential has two vacua. The parity or Z_2 copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to the Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop this idea in the context of a solution to the strong CP problem. Lastly, we show this mechanism postdicts the top Yukawa to be within 1σ of the currently measured value and predicts scalar color octets with masses in the range 9-200 TeV

  2. Carbohydrate metabolism in erythrocytes of copper deficient rats.

    Science.gov (United States)

    Brooks, S P J; Cockell, K A; Dawson, B A; Ratnayake, W M N; Lampi, B J; Belonje, B; Black, D B; Plouffe, L J

    2003-11-01

    Dietary copper deficiency is known to adversely affect the circulatory system of fructose-fed rats. Part of the problem may lie in the effect of copper deficiency on intermediary metabolism. To test this, weanling male Long-Evans rats were fed for 4 or 8 weeks on sucrose-based diets containing low or adequate copper content. Copper deficient rats had significantly lower plasma and tissue copper as well as lower plasma copper, zinc-superoxide dismutase activity. Copper deficient rats also had a significantly higher heart:body weight ratio when compared to pair-fed controls. Direct measurement of glycolysis and pentose phosphate pathway flux in erythrocytes using (13)C NMR showed no differences in carbon flux from glucose or fructose to pyruvate but a significantly higher flux through the lactate dehydrogenase locus in copper deficient rats (approximately 1.3 times, average of glucose and glucose + fructose measurements). Copper-deficient animals had significantly higher erythrocyte concentrations of glucose, fructose, glyceraldehyde 3-phosphate and NAD(+). Liver metabolite levels were also affected by copper deficiency being elevated in glycogen and fructose 1-phosphate content. The results show small changes in carbohydrate metabolism of copper deficient rats.

  3. Problem Based Learning for engineering.

    Science.gov (United States)

    Kumar, Dinesh; Radcliffe, Pj

    2017-07-01

    the role of Problem Based Learning (PBL) is relative clear in domains such as medicine but its efficacy in engineering is as yet less certain. To clarify the role of PBL in engineering, a 3 day workshop was conducted for senior Brazilian engineering academics where they were given the theory and then an immersive PBL experience. One major purpose for running this workshop was for them to identify suitable courses where PBL could be considered. During this workshop, they were split in teams and given a diverse range of problems. At the conclusion of the workshop, a quantifiable survey was conducted and the results show that PBL can deliver superior educational outcomes providing the student group is drawn from the top 5% of the year 12 students, and that significantly higher resources are made available. Thus, any proposed PBL program in engineering must be able to demonstrate that it can meet these requirements before it can move forward to implementation.

  4. German standard problem No. 2

    International Nuclear Information System (INIS)

    Burkhardt, R.

    1980-02-01

    The German Standard Problem Nr. 2 (primary circuits) is meant to check whether the presently available computing programs dealing with ECCS problems are suitable to reflect with sufficient accuracy reload and flooding processes. Changing from conventional calculation methods to the ''best-estimate'' method requires for possibility of exact comparison, as is the case here because of experimental results from the primary circuit test plant. The test plant of KWU Erlangen with primary circuit modeups on a 1:134 scale with exact level indications allows comparative testing where emergency cooling water is loaded into the system filled with saturated steam over cold lanes, or rather over the annulus modeup. The report on hand goes into detail about calculations, anticipated results and their comparison to experimental results. (orig./RW) [de

  5. Numerical models for differential problems

    CERN Document Server

    Quarteroni, Alfio

    2017-01-01

    In this text, we introduce the basic concepts for the numerical modelling of partial differential equations. We consider the classical elliptic, parabolic and hyperbolic linear equations, but also the diffusion, transport, and Navier-Stokes equations, as well as equations representing conservation laws, saddle-point problems and optimal control problems. Furthermore, we provide numerous physical examples which underline such equations. We then analyze numerical solution methods based on finite elements, finite differences, finite volumes, spectral methods and domain decomposition methods, and reduced basis methods. In particular, we discuss the algorithmic and computer implementation aspects and provide a number of easy-to-use programs. The text does not require any previous advanced mathematical knowledge of partial differential equations: the absolutely essential concepts are reported in a preliminary chapter. It is therefore suitable for students of bachelor and master courses in scientific disciplines, an...

  6. ITOUGH2 sample problems

    International Nuclear Information System (INIS)

    Finsterle, S.

    1997-11-01

    This report contains a collection of ITOUGH2 sample problems. It complements the ITOUGH2 User's Guide [Finsterle, 1997a], and the ITOUGH2 Command Reference [Finsterle, 1997b]. ITOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media [Preuss, 1987, 1991a]. The report ITOUGH2 User's Guide [Finsterle, 1997a] describes the inverse modeling framework and provides the theoretical background. The report ITOUGH2 Command Reference [Finsterle, 1997b] contains the syntax of all ITOUGH2 commands. This report describes a variety of sample problems solved by ITOUGH2. Table 1.1 contains a short description of the seven sample problems discussed in this report. The TOUGH2 equation-of-state (EOS) module that needs to be linked to ITOUGH2 is also indicated. Each sample problem focuses on a few selected issues shown in Table 1.2. ITOUGH2 input features and the usage of program options are described. Furthermore, interpretations of selected inverse modeling results are given. Problem 1 is a multipart tutorial, describing basic ITOUGH2 input files for the main ITOUGH2 application modes; no interpretation of results is given. Problem 2 focuses on non-uniqueness, residual analysis, and correlation structure. Problem 3 illustrates a variety of parameter and observation types, and describes parameter selection strategies. Problem 4 compares the performance of minimization algorithms and discusses model identification. Problem 5 explains how to set up a combined inversion of steady-state and transient data. Problem 6 provides a detailed residual and error analysis. Finally, Problem 7 illustrates how the estimation of model-related parameters may help compensate for errors in that model

  7. Managing Classroom Problems.

    Science.gov (United States)

    Long, James D.

    Schools need to meet unique problems through the development of special classroom management techniques. Factors which contribute to classroom problems include lack of supervision at home, broken homes, economic deprivation, and a desire for peer attention. The educational atmosphere should encourage creativity for both the student and the…

  8. Inverse logarithmic potential problem

    CERN Document Server

    Cherednichenko, V G

    1996-01-01

    The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

  9. GREECE--SELECTED PROBLEMS.

    Science.gov (United States)

    MARTONFFY, ANDREA PONTECORVO; AND OTHERS

    A CURRICULUM GUIDE IS PRESENTED FOR A 10-WEEK STUDY OF ANCIENT GREEK CIVILIZATION AT THE 10TH-GRADE LEVEL. TEACHING MATERIALS FOR THE UNIT INCLUDE (1) PRIMARY AND SECONDARY SOURCES DEALING WITH THE PERIOD FROM THE BRONZE AGE THROUGH THE HELLENISTIC PERIOD, (2) GEOGRAPHY PROBLEMS, AND (3) CULTURAL MODEL PROBLEM EXERCISES. THOSE CONCEPTS WITH WHICH…

  10. Solar neutrino problem

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, D J [Australian National Univ., Canberra. Mount Stromlo and Siding Spring Observatories

    1975-10-01

    This paper reviews several recent attempts to solve the problem in terms of modified solar interior models. Some of these have removed the count rate discrepancy, but have violated other observational data for the sun. One successfully accounts for the Davis results at the expense of introducing an ad hoc correction with no current physical explanation. An introductory description of the problem is given.

  11. Reconfigurable layout problem

    NARCIS (Netherlands)

    Meng, G.; Heragu, S.S.; Heragu, S.S.; Zijm, Willem H.M.

    2004-01-01

    This paper addresses the reconfigurable layout problem, which differs from traditional, robust and dynamic layout problems mainly in two aspects: first, it assumes that production data are available only for the current and upcoming production period. Second, it considers queuing performance

  12. The Problems of Dissection.

    Science.gov (United States)

    Davis, Pat

    1997-01-01

    Describes some problems of classroom dissection including the cruelty that animals destined for the laboratory suffer. Discusses the multilevel approach that the National Anti-Vivisection Society (NAVS) has developed to address the problems of animal dissection such as offering a dissection hotline, exhibiting at science teacher conferences, and…

  13. The solar neutrino problem

    International Nuclear Information System (INIS)

    Roxburgh, I.W.

    1981-01-01

    The problems posed by the low flux of neutrinos from the sun detected by Davis and coworkers are reviewed. Several proposals have been advanced to resolve these problems and the more reasonable (in the author's opinion) are presented. Recent claims that the neutrino may have finite mass are also considered. (orig.)

  14. Word Problem Wizardry.

    Science.gov (United States)

    Cassidy, Jack

    1991-01-01

    Presents suggestions for teaching math word problems to elementary students. The strategies take into consideration differences between reading in math and reading in other areas. A problem-prediction game and four self-checking activities are included along with a magic password challenge. (SM)

  15. Problems Facing Rural Schools.

    Science.gov (United States)

    Stewart, C. E.; And Others

    Problems facing rural Scottish schools range from short term consideration of daily operation to long term consideration of organizational alternatives. Addressed specifically, such problems include consideration of: (1) liaison between a secondary school and its feeder primary schools; (2) preservice teacher training for work in small, isolated…

  16. Adaptive Problem Solving

    Science.gov (United States)

    2017-03-01

    Borrajo and Raquel Fuentetaja, Universidad Carlos III de Madrid on the meta-level search architecture for finding good combinations of representations and...heuristics on a problem-by-problem basis. The other is with Carlos Linares also from Universidad Carlos III de Madrid on developing effective

  17. On vector equilibrium problem

    Indian Academy of Sciences (India)

    [G] Giannessi F, Theorems of alternative, quadratic programs and complementarity problems, in: Variational Inequalities and Complementarity Problems (eds) R W Cottle, F Giannessi and J L Lions (New York: Wiley) (1980) pp. 151±186. [K1] Kazmi K R, Existence of solutions for vector optimization, Appl. Math. Lett. 9 (1996).

  18. Users are problem solvers!

    NARCIS (Netherlands)

    Brouwer-Janse, M.D.

    1991-01-01

    Most formal problem-solving studies use verbal protocol and observational data of problem solvers working on a task. In user-centred product-design projects, observational studies of users are frequently used too. In the latter case, however, systematic control of conditions, indepth analysis and

  19. Problems in quantum mechanics

    CERN Document Server

    Goldman, Iosif Ilich; Geilikman, B T

    2006-01-01

    This challenging book contains a comprehensive collection of problems in nonrelativistic quantum mechanics of varying degrees of difficulty. It features answers and completely worked-out solutions to each problem. Geared toward advanced undergraduates and graduate students, it provides an ideal adjunct to any textbook in quantum mechanics.

  20. The JPL functional requirements tool

    Science.gov (United States)

    Giffin, Geoff; Skinner, Judith; Stoller, Richard

    1987-01-01

    Planetary spacecraft are complex vehicles which are built according to many thousands of requirements. Problems encountered in documenting and maintaining these requirements led to the current attempt to reduce or eliminate these problems by a computer automated data base Functional Requirements Tool. The tool developed at JPL and in use on several JPL Projects is described. The organization and functionality of the Tool, together with an explanation of the data base inputs, their relationships, and use are presented. Methods of interfacing with external documents, representation of tables and figures, and methods of approval and change processing are discussed. The options available for disseminating information from the Tool are identified. The implementation of the Requirements Tool is outlined, and the operation is summarized. The conclusions drawn from this work is that the Requirements Tool represents a useful addition to the System Engineer's Tool kit, it is not currently available elsewhere, and a clear development path exists to expand the capabilities of the Tool to serve larger and more complex projects.

  1. Early breastfeeding problems

    DEFF Research Database (Denmark)

    Feenstra, Maria Monberg; Kirkeby, Mette Jørgine; Thygesen, Marianne

    2018-01-01

    Objectives Breastfeeding problems are common and associated with early cessation. Stilllength of postpartum hospital stay has been reduced. This leaves new mothers to establish breastfeeding at home with less support from health care professionals. The objective was to explore mothers’ perspectives...... on when breastfeeding problems were the most challenging and prominent early postnatal. The aim was also toidentify possible factors associated with the breastfeeding problems. Methods In a cross-sectional study, a mixed method approach was used to analyse postal survey data from 1437 mothers with full...... term singleton infants. Content analysis was used to analyse mothers’ open text descriptions of their most challenging breastfeeding problem. Multiple logistic regression was used to calculate odds ratios for early breastfeeding problems according to sociodemographic- and psychosocial factors. Results...

  2. Problems in abstract algebra

    CERN Document Server

    Wadsworth, A R

    2017-01-01

    This is a book of problems in abstract algebra for strong undergraduates or beginning graduate students. It can be used as a supplement to a course or for self-study. The book provides more variety and more challenging problems than are found in most algebra textbooks. It is intended for students wanting to enrich their learning of mathematics by tackling problems that take some thought and effort to solve. The book contains problems on groups (including the Sylow Theorems, solvable groups, presentation of groups by generators and relations, and structure and duality for finite abelian groups); rings (including basic ideal theory and factorization in integral domains and Gauss's Theorem); linear algebra (emphasizing linear transformations, including canonical forms); and fields (including Galois theory). Hints to many problems are also included.

  3. Solved problems in electrochemistry

    International Nuclear Information System (INIS)

    Piron, D.L.

    2004-01-01

    This book presents calculated solutions to problems in fundamental and applied electrochemistry. It uses industrial data to illustrate scientific concepts and scientific knowledge to solve practical problems. It is subdivided into three parts. The first uses modern basic concepts, the second studies the scientific basis for electrode and electrolyte thermodynamics (including E-pH diagrams and the minimum energy involved in transformations) and the kinetics of rate processes (including the energy lost in heat and in parasite reactions). The third part treats larger problems in electrolysis and power generation, as well as in corrosion and its prevention. Each chapter includes three sections: the presentation of useful principles; some twenty problems with their solutions; and, a set of unsolved problems

  4. The Guderley problem revisited

    International Nuclear Information System (INIS)

    Ramsey, Scott D.; Kamm, James R.; Bolstad, John H.

    2009-01-01

    The self-similar converging-diverging shock wave problem introduced by Guderley in 1942 has been the source of numerous investigations since its publication. In this paper, we review the simplifications and group invariance properties that lead to a self-similar formulation of this problem from the compressible flow equations for a polytropic gas. The complete solution to the self-similar problem reduces to two coupled nonlinear eigenvalue problems: the eigenvalue of the first is the so-called similarity exponent for the converging flow, and that of the second is a trajectory multiplier for the diverging regime. We provide a clear exposition concerning the reflected shock configuration. Additionally, we introduce a new approximation for the similarity exponent, which we compare with other estimates and numerically computed values. Lastly, we use the Guderley problem as the basis of a quantitative verification analysis of a cell-centered, finite volume, Eulerian compressible flow algorithm.

  5. Structural Identification Problem

    Directory of Open Access Journals (Sweden)

    Suvorov Aleksei

    2016-01-01

    Full Text Available The identification problem of the existing structures though the Quasi-Newton and its modification, Trust region algorithms is discussed. For the structural problems, which could be represented by means of the mathematical modelling of the finite element code discussed method is extremely useful. The nonlinear minimization problem of the L2 norm for the structures with linear elastic behaviour is solved by using of the Optimization Toolbox of Matlab. The direct and inverse procedures for the composition of the desired function to minimize are illustrated for the spatial 3D truss structure as well as for the problem of plane finite elements. The truss identification problem is solved with 2 and 3 unknown parameters in order to compare the computational efforts and for the graphical purposes. The particular commands of the Matlab codes are present in this paper.

  6. The moment problem

    CERN Document Server

    Schmüdgen, Konrad

    2017-01-01

    This advanced textbook provides a comprehensive and unified account of the moment problem. It covers the classical one-dimensional theory and its multidimensional generalization, including modern methods and recent developments. In both the one-dimensional and multidimensional cases, the full and truncated moment problems are carefully treated separately. Fundamental concepts, results and methods are developed in detail and accompanied by numerous examples and exercises. Particular attention is given to powerful modern techniques such as real algebraic geometry and Hilbert space operators. A wide range of important aspects are covered, including the Nevanlinna parametrization for indeterminate moment problems, canonical and principal measures for truncated moment problems, the interplay between Positivstellensätze and moment problems on semi-algebraic sets, the fibre theorem, multidimensional determinacy theory, operator-theoretic approaches, and the existence theory and important special topics of multidime...

  7. Morphologic and biochemical changes in male rat lung after surgical and pharmacological castration

    Directory of Open Access Journals (Sweden)

    M.S. Ojeda

    2000-03-01

    Full Text Available The morphology of the rat lung was studied by light microscopy in different situations: after surgical and pharmacological castration and after administration of testosterone to the castrated rat to determine if the androgen is required to maintain the normal morphology of the lung. We also determined the effect of flutamide on the phospholipid composition of both the surfactant and microsomes of the lung. Rats were separated into five groups: I - control non-castrated rats, II - castrated rats sacrificed 21 days after castration, III - castrated rats that received testosterone daily from day 2 to day 21 after castration, IV - castrated rats that received testosterone from day 15 to day 21 after castration, and V - control rats injected with flutamide for 7 days. The amount of different phospholipids in the surfactant and microsomes of the lung was measured in group I and V rats. At the light microscopy level, the surgical and pharmacological castration provoked alterations in the morphology of the lung, similar to that observed in human lung emphysema. The compositions of surfactant and microsomes of the lung were similar to those previously reported by us for the surgically castrated rats. These results indicate that androgens are necessary for the normal morphology as well as for some metabolic aspects of the lung.

  8. An Efficient Method for Generation of Transgenic Rats Avoiding Embryo Manipulation

    Directory of Open Access Journals (Sweden)

    Bhola Shankar Pradhan

    2016-01-01

    Full Text Available Although rats are preferred over mice as an animal model, transgenic animals are generated predominantly using mouse embryos. There are limitations in the generation of transgenic rat by embryo manipulation. Unlike mouse embryos, most of the rat embryos do not survive after male pronuclear DNA injection which reduces the efficiency of generation of transgenic rat by this method. More importantly, this method requires hundreds of eggs collected by killing several females for insertion of transgene to generate transgenic rat. To this end, we developed a noninvasive and deathless technique for generation of transgenic rats by integrating transgene into the genome of the spermatogonial cells by testicular injection of DNA followed by electroporation. After standardization of this technique using EGFP as a transgene, a transgenic disease model displaying alpha thalassemia was successfully generated using rats. This efficient method will ease the generation of transgenic rats without killing the lives of rats while simultaneously reducing the number of rats used for generation of transgenic animal.

  9. Comparison of febrile responsiveness of rats and rabbits to endogenous pyrogen.

    Science.gov (United States)

    Stitt, J T; Shimada, S G; Bernheim, H A

    1985-12-01

    The fever responses of rats and rabbits were compared in detail using a single common source of semipurified endogenous pyrogen prepared from human monocytes. The characteristics and dynamics of the fever-response curves for each species were examined and their dose-response curves were determined and compared. The fevers displayed by rats were qualitatively similar to those of rabbits, but, typically, they developed and terminated more rapidly than those of rabbits. Rabbits were much more sensitive to the endogenous pyrogen than rats. The threshold dose of pyrogen required to elicit a fever was 5 times lower in the rabbit, and the slope of the rabbit's dose-response curve was 1.5 times steeper than that of the rat. The maximum fevers attainable in rabbits were approximately twice those attainable in rats. It was also shown that the more rapid febrile responses of the rat were not due to the 10-fold smaller mass of the rat; instead, we proposed that this difference was more likely due to a closer diffusional proximity of the pyrogen receptor sites to the circulation in rats. The lower sensitivity of the rat to endogenous pyrogen was attributed to a relative insensitivity of the pyrogen receptor sites in rats in the translation of the endogenous pyrogen stimulus into fever.

  10. Sex differences underlying orofacial varicella zoster associated pain in rats.

    Science.gov (United States)

    Stinson, Crystal; Deng, Mohong; Yee, Michael B; Bellinger, Larry L; Kinchington, Paul R; Kramer, Phillip R

    2017-05-17

    Most people are initially infected with varicella zoster virus (VZV) at a young age and this infection results in chickenpox. VZV then becomes latent and reactivates later in life resulting in herpes zoster (HZ) or "shingles". Often VZV infects neurons of the trigeminal ganglia to cause ocular problems, orofacial disease and occasionally a chronic pain condition termed post-herpetic neuralgia (PHN). To date, no model has been developed to study orofacial pain related to varicella zoster. Importantly, the incidence of zoster associated pain and PHN is known to be higher in women, although reasons for this sex difference remain unclear. Prior to this work, no animal model was available to study these sex-differences. Our goal was to develop an orofacial animal model for zoster associated pain which could be utilized to study the mechanisms contributing to this sex difference. To develop this model VZV was injected into the whisker pad of rats resulting in IE62 protein expression in the trigeminal ganglia; IE62 is an immediate early gene in the VZV replication program. Similar to PHN patients, rats showed retraction of neurites after VZV infection. Treatment of rats with gabapentin, an agent often used to combat PHN, ameliorated the pain response after whisker pad injection. Aversive behavior was significantly greater for up to 7 weeks in VZV injected rats over control inoculated rats. Sex differences were also seen such that ovariectomized and intact female rats given the lower dose of VZV showed a longer affective response than male rats. The phase of the estrous cycle also affected the aversive response suggesting a role for sex steroids in modulating VZV pain. These results suggest that this rat model can be utilized to study the mechanisms of 1) orofacial zoster associated pain and 2) the sex differences underlying zoster associated pain.

  11. Assertiveness and problem solving in midwives.

    Science.gov (United States)

    Yurtsal, Zeliha Burcu; Özdemir, Levent

    2015-01-01

    Midwifery profession is required to bring solutions to problems and a midwife is expected to be an assertive person and to develop midwifery care. This study was planned to examine the relationship between assertiveness and problem-solving skills of midwives. This cross-sectional study was conducted with 201 midwives between July 2008 and February 2009 in the city center of Sivas. The Rathus Assertiveness Schedule (RAS) and Problem Solving Inventory (PSI) were used to determine the level of assertiveness and problem-solving skills of midwives. Statistical methods were used as mean, standard deviation, percentage, Student's T, ANOVA and Tukey HSD, Kruskal Wallis, Fisher Exact, Pearson Correlation and Chi-square tests and P problem-solving skills training. A statistically significant negative correlation was found between the RAS and PSI scores. The RAS scores decreased while the problem-solving scores increased (r: -0451, P problem solving skills of midwives, and midwives who were assertive solved their problems better than did others. Assertiveness and problem-solving skills training will contribute to the success of the midwifery profession. Midwives able to solve problems, and display assertive behaviors will contribute to the development of midwifery profession.

  12. SCHOOL VIOLENCE: A COMPLEX PROBLEM

    Directory of Open Access Journals (Sweden)

    María del Rosario Ayala-Carrillo

    2015-07-01

    Full Text Available School violence is one type of violence that reflects the breakdown of current society. It is impossible to speak of school violence as an isolated phenomenon without establishing nexuses between public and private life, between collective and individual behaviors, between family and community aspects, without making reference to differences in gender and the life stories of those who are the aggressors or the victims, and without considering the patriarchal culture and interpersonal relationships. When all these factor are interrelated, they make the problem of violence a very complex one that requires us to know the different factors in order to understand it and deal with it.

  13. Feed tank transfer requirements

    International Nuclear Information System (INIS)

    Freeman-Pollard, J.R.

    1998-01-01

    This document presents a definition of tank turnover; DOE responsibilities; TWRS DST permitting requirements; TWRS Authorization Basis (AB) requirements; TWRS AP Tank Farm operational requirements; unreviewed safety question (USQ) requirements; records and reporting requirements, and documentation which will require revision in support of transferring a DST in AP Tank Farm to a privatization contractor for use during Phase 1B

  14. Structure of the vitreoretinal border region in spontaneously hypertensive rats (SHR rats)

    DEFF Research Database (Denmark)

    Heegaard, Steffen

    1993-01-01

    Øjenpatologi, vitreoretinal border region, inner limiting membrane of the retina, spontaneously hypertensive rats, SHR rats, ultrastructure......Øjenpatologi, vitreoretinal border region, inner limiting membrane of the retina, spontaneously hypertensive rats, SHR rats, ultrastructure...

  15. COAL DUST EMISSION PROBLEM

    Directory of Open Access Journals (Sweden)

    M. M. Biliaiev

    2016-12-01

    Full Text Available Purpose. The article aims to develop 2D numerical models for the prediction of atmospheric pollution during transportation of coal in the railway car, as well as the ways to protect the environment and the areas near to the mainline from the dust emission due to the air injection installation. Methodology. To solve this problem there were developed numerical models based on the use of the equations of motion of an inviscid incompressible fluid and mass transfer. For the numerical integration of the transport equation of the pollutant the implicit alternating-triangular difference scheme was used. For numerical integration of the 2D equation for the velocity potential the method of total approximation was used. The developed numerical models are the basis of established software package. On the basis of the constructed numerical models it was carried out a computational experiment to assess the level of air pollution when transporting bulk cargo by rail when the railway car has the air injection. Findings. 2D numerical models that belong to the class «diagnostic models» were developed. These models take into account the main physical factors affecting the process of dispersion of dust pollution in the atmosphere during transportation of bulk cargo. The developed numerical models make it possible to calculate the dust loss process, taking into account the use of the air injection of the car. They require a small cost of the computer time during practical realization at the low and medium power machines. There were submitted computational calculations to determine pollutant concentrations and the formation of the zone of pollution near the train with bulk cargo in «microscale» scale taking into account the air curtains. Originality. 2D numerical models taking into account the relevant factors influencing the process of dispersion of pollutants in the atmosphere, and the formation of the zone of pollution during transportation of bulk cargo by

  16. Brauer type embedding problems

    CERN Document Server

    Ledet, Arne

    2005-01-01

    This monograph is concerned with Galois theoretical embedding problems of so-called Brauer type with a focus on 2-groups and on finding explicit criteria for solvability and explicit constructions of the solutions. The advantage of considering Brauer type embedding problems is their comparatively simple condition for solvability in the form of an obstruction in the Brauer group of the ground field. This book presupposes knowledge of classical Galois theory and the attendant algebra. Before considering questions of reducing the embedding problems and reformulating the solvability criteria, the

  17. Astronauts' menu problem.

    Science.gov (United States)

    Lesso, W. G.; Kenyon, E.

    1972-01-01

    Consideration of the problems involved in choosing appropriate menus for astronauts carrying out SKYLAB missions lasting up to eight weeks. The problem of planning balanced menus on the basis of prepackaged food items within limitations on the intake of calories, protein, and certain elements is noted, as well as a number of other restrictions of both physical and arbitrary nature. The tailoring of a set of menus for each astronaut on the basis of subjective rankings of each food by the astronaut in terms of a 'measure of pleasure' is described, and a computer solution to this problem by means of a mixed integer programming code is presented.

  18. Where is the problem?

    International Nuclear Information System (INIS)

    Levy-Leblond, J.-M.

    1990-01-01

    This paper examines the problem of the reduction of the state vector in quantum theory. The author suggest that this issue ceases to cause difficulties if viewed from the correct perspective, for example by giving the state vector an auxiliary rather than fundamental status. He advocates changing the conceptual framework of quantum theory and working with quantons rather than particles and/or waves. He denies that reduction is a psychophysiological problem of observation, and raises the relevance of experimental apparatus. He concludes by venturing the suggestion that the problem of the reduction of the quantum state vector lies, not in quantum theory, but in classical perspectives. (UK)

  19. Rat bite fever.

    NARCIS (Netherlands)

    Gaastra, W.; Boot, R.G.A.; Ho, H.; Lipman, L.J.A.

    2009-01-01

    Rat bite fever (RBF) is a bacterial zoonosis for which two causal bacterial species have been identified: Streptobacillis moniliformis and Spirillum minus. Haverhill fever (HF) is a form of S. moniliformis infection believed to develop after ingestion of contaminated food or water. Here the

  20. Usability Problems in a Home Telemedicine System

    DEFF Research Database (Denmark)

    Bruun, Anders; Stage, Jan

    2010-01-01

    a high level of usability in order to enable their users to employ the required functionality, especially if the target user group is elderly people. This paper reports from a usability evaluation of a home telemedicine system. Five elderly persons carried out specified tasks with the system, and based...... on that we identified usability problems with the system. The problems are presented, analysed in relation to 12 different usability themes and related to results from other evaluations of similar systems....

  1. Separable boundary-value problems in physics

    CERN Document Server

    Willatzen, Morten

    2011-01-01

    Innovative developments in science and technology require a thorough knowledge of applied mathematics, particularly in the field of differential equations and special functions. These are relevant in modeling and computing applications of electromagnetic theory and quantum theory, e.g. in photonics and nanotechnology. The problem of solving partial differential equations remains an important topic that is taught at both the undergraduate and graduate level. Separable Boundary-Value Problems in Physics is an accessible and comprehensive treatment of partial differential equations i

  2. Bridging disciplines through problem based learning

    DEFF Research Database (Denmark)

    Stentoft, Diana

    2011-01-01

    This paper examines whether a problem based approach to students’ learning may support interdisciplinary education at university level, where students are required to engage with the complexities inherent in constructing knowledge across disciplinary boundaries. These complexities include students...... engaging with multiple and conflicting epistemologies, identification and contextualisation of problems involving several disciplines in their solution etc. A practical example found in the case of newly developed BSc and MSc programs in Techno-Anthropology is provided.The paper includes some examples...

  3. Woman Entrepreneurship in Haryana: Challenges and Problems.

    OpenAIRE

    Sanchita

    2013-01-01

    The paper highlights the various problems and challenges faced by woman entrepreneurs while running the enterprises in the present competitive world of today which is both healthy as well as unhealthy. The problems of women entrepreneurs include working capital, distribution channel, sales promotion, electricity, human resources and competition with medium and large industries. To justify the need of the present study we have reviewed the literature. To draw policy implications we are require...

  4. Requirements of quality standards

    International Nuclear Information System (INIS)

    Mueller, J.

    1977-01-01

    The lecture traces the development of nuclear standards, codes, and Federal regulations on quality assurance (QA) for nuclear power plants and associated facilities. The technical evolution of the last twelve years, especially in the area of nuclear technology, led to different activities and regulatory initiatives, and the present result is: several nations have their own homemade standards. The lecture discusses the former and especially current activities in standard development, and gives a description of the requirements of QA-standards used in USA and Europe, especially Western Germany. Furthermore the lecture attempts to give a comparison and an evaluation of the international quality standards from the author's viewpoint. Finally the lecture presents an outlook for the future international implications of QA-standards. There is an urgent need within the nuclear industry for simplification and standardization of QA-standards. The relationship between the various standards, and the applicability of the standards need clarification and a better transparancy. To point out these problems is the purpose of the lecture. (orig.) [de

  5. Some mass measurement problems

    International Nuclear Information System (INIS)

    Merritt, J.S.

    1976-01-01

    Concerning the problem of determining the thickness of a target, an uncomplicated approach is to measure its mass and area and take the quotient. This paper examines the mass measurement aspect of such an approach. (author)

  6. The cosmological constant problem

    International Nuclear Information System (INIS)

    Dolgov, A.D.

    1989-05-01

    A review of the cosmological term problem is presented. Baby universe model and the compensating field model are discussed. The importance of more accurate data on the Hubble constant and the Universe age is stressed. 18 refs

  7. Diabetic Eye Problems

    Science.gov (United States)

    ... damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause of blindness ... You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your ...

  8. Problems in optics

    CERN Document Server

    Rousseau, Madeleine; Ter Haar, D

    1973-01-01

    This collection of problems and accompanying solutions provide the reader with a full introduction to physical optics. The subject coverage is fairly traditional, with chapters on interference and diffraction, and there is a general emphasis on spectroscopy.

  9. Mouth Problems and HIV

    Science.gov (United States)

    ... teeth (periodontitis), canker sores, oral warts, fever blisters, oral candidiasis (thrush), hairy leukoplakia (which causes a rough, white patch on the tongue), and dental caries. Read More Publications Cover image Mouth Problems + HIV Publication files Download Language English PDF — ...

  10. Problem Based Game Design

    DEFF Research Database (Denmark)

    Reng, Lars; Schoenau-Fog, Henrik

    2011-01-01

    At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various ...... projects and how they learn to analyse, design, and develop for innovation by using it. We will present various cases to exemplify the approach and focus on how the method engages students and aspires for innovation in digital entertainment and games.......At Aalborg University’s department of Medialogy, we are utilizing the Problem Based Learning method to encourage students to solve game design problems by pushing the boundaries and designing innovative games. This paper is concerned with describing this method, how students employ it in various...

  11. Neutrosophic Integer Programming Problem

    Directory of Open Access Journals (Sweden)

    Mai Mohamed

    2017-02-01

    Full Text Available In this paper, we introduce the integer programming in neutrosophic environment, by considering coffecients of problem as a triangulare neutrosophic numbers. The degrees of acceptance, indeterminacy and rejection of objectives are simultaneously considered.

  12. Open problems in mathematics

    CERN Document Server

    Nash, Jr, John Forbes

    2016-01-01

    The goal in putting together this unique compilation was to present the current status of the solutions to some of the most essential open problems in pure and applied mathematics. Emphasis is also given to problems in interdisciplinary research for which mathematics plays a key role. This volume comprises highly selected contributions by some of the most eminent mathematicians in the international mathematical community on longstanding problems in very active domains of mathematical research. A joint preface by the two volume editors is followed by a personal farewell to John F. Nash, Jr. written by Michael Th. Rassias. An introduction by Mikhail Gromov highlights some of Nash’s legendary mathematical achievements. The treatment in this book includes open problems in the following fields: algebraic geometry, number theory, analysis, discrete mathematics, PDEs, differential geometry, topology, K-theory, game theory, fluid mechanics, dynamical systems and ergodic theory, cryptography, theoretical computer sc...

  13. [Current problems of deontology].

    Science.gov (United States)

    Dimov, A S

    2010-01-01

    The scope of knowledge in medical ethics continues to extend. Deontology as a science needs systematization of the accumulated data. This review may give impetus to classification of problems pertaining to this important area of medical activity.

  14. Health Problems at School

    Science.gov (United States)

    ... the Word Shop AAP Find a Pediatrician Ages & Stages Prenatal Baby Toddler Preschool Gradeschool Fitness Nutrition Puberty School Teen Young Adult Healthy Children > Ages & Stages > Gradeschool > School > Health Problems at School Ages & Stages ...

  15. Challenging problems in geometry

    CERN Document Server

    Posamentier, Alfred S

    1996-01-01

    Collection of nearly 200 unusual problems dealing with congruence and parallelism, the Pythagorean theorem, circles, area relationships, Ptolemy and the cyclic quadrilateral, collinearity and concurrency and more. Arranged in order of difficulty. Detailed solutions.

  16. A nonlinear oscillatory problem

    International Nuclear Information System (INIS)

    Zhou Qingqing.

    1991-10-01

    We have studied the nonlinear oscillatory problem of orthotropic cylindrical shell, we have analyzed the character of the oscillatory system. The stable condition of the oscillatory system has been given. (author). 6 refs

  17. Problems of research politics

    International Nuclear Information System (INIS)

    Luest, R.

    1977-01-01

    The development in the FRG is portrayed. Illustrated by a particular example, the problems of basic research and of the scientists are presented looking back, looking at the present, and into the future. (WB) [de

  18. Quantum first passage problem

    International Nuclear Information System (INIS)

    Kumar, N.

    1984-07-01

    Quantum first passage problem (QUIPP) is formulated and solved in terms of a constrained Feynman path integral. The related paradox of blocking of unitary evolution by continuous observation on the system implicit in QUIPP is briefly discussed. (author)

  19. Teaching Creative Problem Solving.

    Science.gov (United States)

    Christensen, Kip W.; Martin, Loren

    1992-01-01

    Interpersonal and cognitive skills, adaptability, and critical thinking can be developed through problem solving and cooperative learning in technology education. These skills have been identified as significant needs of the workplace as well as for functioning in society. (SK)

  20. To the confinement problem

    International Nuclear Information System (INIS)

    Savvidi, G.K.

    1985-01-01

    Such a viewpoint is proposed for separation of the physical quantities into observable and unobservable ones, when the latters are connected with the Hermitian operator for which the eigenvalue problem is unsolvable

  1. EVALUATION OF SOME ANTIOXIDANTS TREATMENT ON KIDNEY FUNCTION AND LIPID PEROXIDATION STATUS IN HYPERTENSIVE RATS INDUCED WITH L-NAME

    International Nuclear Information System (INIS)

    MATTA, T.F.

    2008-01-01

    Hypertension, the disease known as the s ilent killer , is a common problem facing peoples today with million new cases being diagnosed each year. Although a great amount of money is spent annually for the treatment and detection of this disease and its complications, current conventional treatment have done little to reduce the number of patients with hypertension. Research has found a variety of alternative therapies to be successful in reducing high blood pressure including diet, exercise, stress management, supplements and herbs.In this study, the changes in some selected biochemical blood variables, which are thought to represent risk factors coincident with hypertension and kidney function, were compared between a group of normotensive male albino rats and other group suffered from hypertension induced artificially by N-nitro-L-arginine methyl ester (L-NAME). Also, this study investigated the effects of daily administration of some antioxidants nutrients for two weeks namely carnitine, coenzyme Q 1 0 , garlic oil and their mixture on the same variables in order to show to what extent these nutrients are valid to control the levels of these variables without any deleterious effects after treatment. Fifty mg of coenzyme Q 10 and 50 mg of carnitine were daily injected intraperitoneally for two weeks in two groups of hypertensive rats while 200 mg/kg b.wt was given to another group of hypertensive rats by oral intubation. A combination of all the above mentioned nutrients was given to the fourth group. Another hypertensive group was left without any treatment and served as a recovery group. Fasting blood samples were drawn and kidney tissues were taken at the terminal of treatments.The obtained results revealed that induced hypertension caused significant (P<0.05) increase of thiobarbeturic acid reactive substances (TBARs), malondialdehyde (MAD), parathormone (PTH), renin, blood urea, creatinine, phosphorus, sodium and potassium while glutathione (GSH), calcium

  2. Accelerator shielding benchmark problems

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  3. Shielding benchmark problems

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Kawai, Masayoshi; Nakazawa, Masaharu.

    1978-09-01

    Shielding benchmark problems were prepared by the Working Group of Assessment of Shielding Experiments in the Research Comittee on Shielding Design of the Atomic Energy Society of Japan, and compiled by the Shielding Laboratory of Japan Atomic Energy Research Institute. Twenty-one kinds of shielding benchmark problems are presented for evaluating the calculational algorithm and the accuracy of computer codes based on the discrete ordinates method and the Monte Carlo method and for evaluating the nuclear data used in the codes. (author)

  4. The solar neutrino problem

    International Nuclear Information System (INIS)

    Bahcall, J.N.

    1986-01-01

    The observed capture rate for solar neutrinos in the /sup 37/Cl detector is lower than the predicted capture rate. This discrepancy between theory and observation is known as the 'solar neutrino problem.' The author reviews the basic elements in this problem: the detector efficiency, the theory of stellar (solar) evolution, the nuclear physics of energy generation, and the uncertainties in the predictions. He also answers the questions of: So What? and What Next?

  5. Solving radwaste problems

    International Nuclear Information System (INIS)

    Oyen, L.C.

    1976-01-01

    The combination of regulatory changes and increased waste volume has resulted in design changes in waste processing systems. Problems resulting from waste segregation as a basis for design philosophy are considered, and solutions to the problems are suggested. The importance of operator training, maintenance procedures, good housekeeping, water management, and offsite shipment of solids is discussed. Flowsheets for radioactive waste processing systems for boiling water reactors and pressurized water reactors are included

  6. The gauge hierarchy problem

    International Nuclear Information System (INIS)

    Natale, A.A.; Shellard, R.C.

    1981-01-01

    The problem of gauge hierarchy in Grand Unified Theories using a toy model with O(N) symmetry is discussed. It is shown that there is no escape to the unnatural adjustment of coupling constants, made only after the computation of several orders in perturbation theory is performed. The propositions of some authors on ways to overcome the gauge hierarchy problem are commented. (Author) [pt

  7. Problems of Forecast

    OpenAIRE

    Kucharavy , Dmitry; De Guio , Roland

    2005-01-01

    International audience; The ability to foresee future technology is a key task of Innovative Design. The paper focuses on the obstacles to reliable prediction of technological evolution for the purpose of Innovative Design. First, a brief analysis of problems for existing forecasting methods is presented. The causes for the complexity of technology prediction are discussed in the context of reduction of the forecast errors. Second, using a contradiction analysis, a set of problems related to ...

  8. Caffeine dependence in rats: effects of exposure duration and concentration.

    Science.gov (United States)

    Dingle, Rachel N; Dreumont-Boudreau, Sarah E; Lolordo, Vincent M

    2008-09-03

    Groups of rats were chronically exposed to a 1.0-g/L caffeine solution for 5, 10, 15 or 20 days. Upon removal of caffeine, rats were given brief exposure to a novel flavour CS (withdrawal CS) followed by 12 days of plain water and then brief exposure to a second flavour CS (neutral CS). Only rats exposed to 20 days of caffeine strongly preferred the neutral CS to the withdrawal CS in a 2-bottle test. In Experiment 2, groups of rats were chronically exposed to caffeine at one of four concentrations (1.0, 0.5, 0.25, or 0.125 g/L) for 21 days, after which withdrawal and neutral CSs were established. Only rats that drank the highest caffeine concentration, 1.0 g/L, preferred the neutral CS to the withdrawal CS. This suggests that long exposure to a strong caffeine solution is required in order to induce dependence in rats such that a CS associated with the withdrawal of caffeine becomes avoided.

  9. Basolateral amygdala lesions abolish mutual reward preferences in rats.

    Science.gov (United States)

    Hernandez-Lallement, Julen; van Wingerden, Marijn; Schäble, Sandra; Kalenscher, Tobias

    2016-01-01

    In a recent study, we demonstrated that rats prefer mutual rewards in a Prosocial Choice Task. Here, employing the same task, we show that the integrity of basolateral amygdala was necessary for the expression of mutual reward preferences. Actor rats received bilateral excitotoxic (n=12) or sham lesions (n=10) targeting the basolateral amygdala and were subsequently tested in a Prosocial Choice Task where they could decide between rewarding ("Both Reward") or not rewarding a partner rat ("Own Reward"), either choice yielding identical reward to the actors themselves. To manipulate the social context and control for secondary reinforcement sources, actor rats were paired with either a partner rat (partner condition) or with an inanimate rat toy (toy condition). Sham-operated animals revealed a significant preference for the Both-Reward-option in the partner condition, but not in the toy condition. Amygdala-lesioned animals exhibited significantly lower Both-Reward preferences than the sham group in the partner but not in the toy condition, suggesting that basolateral amygdala was required for the expression of mutual reward preferences. Critically, in a reward magnitude discrimination task in the same experimental setup, both sham-operated and amygdala-lesioned animals preferred large over small rewards, suggesting that amygdala lesion effects were restricted to decision making in social contexts, leaving self-oriented behavior unaffected. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Problems of radiation protection optimization

    International Nuclear Information System (INIS)

    Morkunas, G.

    2003-01-01

    One of the basic principles - optimization of radiation protection - is rather well understood by everybody engaged in protection of humans from ionizing radiation. However, the practical application of this principle is very problematic. This fact can be explained by vagueness of concept of dose constraints, possible legal consequences of any decision based on this principle, traditions of prescriptive system of radiation protection requirements in some countries, insufficiency of qualified expertise. The examples of optimization problems are the different attention given to different kinds of practices, not optimized application of remedial measures, strict requirements for radioactive contamination of imported products, uncertainties in optimization in medical applications of ionizing radiation. Such tools as international co-operation including regional networks of information exchange, training of qualified experts, identification of measurable indicators used for judging about the level of optimization may be the helpful practical means in solving of these problems. It is evident that the principle of optimization can not be replaced by any other alternative despite its complexity. The means for its practical implementation shall be searched for. (author)

  11. Causality problem in atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Bor, N

    1985-10-01

    The casuality problem in atomic physics is analysed by Bohr in a wide methodological context. The first part of the paper is a short historical essay picturing the entry of statistical concepts into physics. Bohr underlines a close relationship between an unavoidably probabilitic nature of the quantum theory and quantum postulates introducing the alien-to-classical-physics concepts of integrity, individuality of atomic processes. In the second central part of the paper Bohr discusses the casuality problems in atomic physics in detail and shows that their solution requires a careful analysis of the observation process. Proceeding from the program methodological requirement to describe the measuring instrumentation operation and observation results in the language of classical physics, he explains that the statistical character of the uncertainty relationships expresses a substantial specifically quantum constraint to the applicifically of classical conceptions analyses of microphenomena. Then Bohr refines in principle the notion ''phenomenon'', as one of the central notions among those he employed for the formulation of his complementarity principle. According to bohr a phenomenon should be under-stood as an unambiguously present situation of a completed experiment. Therefore, it is erroneous to speak of the phenomenon perturbation by the observation. The final part of the article deals with the discussion of methodological parallels of the quantum theory and relativity theory.

  12. [Psychosocial problems and needs among cancer patients].

    Science.gov (United States)

    Mehlsen, Mimi Yung; Jensen, Anders Bonde; Zachariae, Bobby

    2007-04-30

    Cancer can have a serious impact on patient well-being and quality of life. The international literature reports a higher prevalence of psychosocial problems among cancer patients; primarily problems associated with difficulties in the family, duties in the household, work and leisure, sexuality and finances. The prevalence of these problems among Danish cancer patients is still unknown. A questionnaire assessing psychosocial problems and needs was mailed out to all patients who had been at the Department of Oncology, Aarhus Hospital in week 35, 2004. A total of 71%, i.e. 515 patients (34% men and 66% women) in active treatment and control returned the questionnaire. High levels of emotional distress were reported by 39% of the patients. High levels of distress were primarily related to problems with worries about their spouses, household duties, financial problems and experiences of insufficient collaboration between health care and social services. Between 19% and 25% of the patients required further help to handle emotional problems, legal and financial problems and practical problems in the home. A considerable proportion of oncology patients experience significant levels of distress. This group of distressed patients also report unmet needs for psychosocial support.

  13. Problem of Information Security Traffic on Internet

    Directory of Open Access Journals (Sweden)

    Slavko Šarić

    2012-10-01

    Full Text Available Internet information traffic becomes greater and moreimportant. With increasing growth of information importancerequirement for its security becomes indispensable. Theinformation security problem especially affect large and smallcompanies whose prosperity is depending on Internet presence.This affecting the three areas of Internet commerce: credit cardtransactions, virtual private networks and digital certification.To ensure information traffic it is necessary to find a solution,in a proper way, for three major problems: frontier problem,market problem and government problem. While the eventualemergence of security standards for Internet transactions isexpected, it will not automatically result in secure Internettransactions. In future, there is a wealth of security issues thatwill continue to require attention: internal security, continuedhacking, social engineering, malicious code, reliability andperformance, skills shortages and denial of se1vice attacks.

  14. Dreams and creative problem-solving.

    Science.gov (United States)

    Barrett, Deirdre

    2017-10-01

    Dreams have produced art, music, novels, films, mathematical proofs, designs for architecture, telescopes, and computers. Dreaming is essentially our brain thinking in another neurophysiologic state-and therefore it is likely to solve some problems on which our waking minds have become stuck. This neurophysiologic state is characterized by high activity in brain areas associated with imagery, so problems requiring vivid visualization are also more likely to get help from dreaming. This article reviews great historical dreams and modern laboratory research to suggest how dreams can aid creativity and problem-solving. © 2017 New York Academy of Sciences.

  15. Harmful effect of protein difficiency on lipids, glucose, insulin and estradiol levels in female albino rats

    International Nuclear Information System (INIS)

    El-Mahdy, A.A.; El-Sherbiny, E.M.; Bayomi, M.M.

    2005-01-01

    The present study was undertaken to investigate the harmful effect of protein deficient diet on some biochemical activities in serum of female rats. Protein malnutrition is a well known socioeconomic problem in different parts of the world. Many studies were investigated on the biological parameters following protein malnutrition in human and experimental animals. Forty albino female rats were divided into 3 groups. The first group (10 rats) fed 18% protein diet and served as normal control and the other two groups, each contains 15 rats, fed 5% protein for 21 and 45 days, respectively, and served as malnourished groups. The results showed significant decrease in total body weight, serum glucose, insulin and estradiol levels in the third group as well as decrease in the total cholesterol, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol and triglycerides concentrations that compared to normal control rats

  16. 48 CFR 29.101 - Resolving tax problems.

    Science.gov (United States)

    2010-10-01

    .... (d) Before purchasing goods or services from a foreign source, the contracting officer should consult... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Resolving tax problems. 29... CONTRACTING REQUIREMENTS TAXES General 29.101 Resolving tax problems. (a) Contract tax problems are...

  17. Computational sieving applied to some classical number-theoretic problems

    NARCIS (Netherlands)

    H.J.J. te Riele (Herman)

    1998-01-01

    textabstractMany problems in computational number theory require the application of some sieve. Efficient implementation of these sieves on modern computers has extended our knowledge of these problems considerably. This is illustrated by three classical problems: the Goldbach conjecture, factoring

  18. Development of the PEBLebl Traveling Salesman Problem Computerized Testbed

    Science.gov (United States)

    Mueller, Shane T.; Perelman, Brandon S.; Tan, Yin Yin; Thanasuan, Kejkaew

    2015-01-01

    The traveling salesman problem (TSP) is a combinatorial optimization problem that requires finding the shortest path through a set of points ("cities") that returns to the starting point. Because humans provide heuristic near-optimal solutions to Euclidean versions of the problem, it has sometimes been used to investigate human visual…

  19. A Rubric for Assessing Students' Experimental Problem-Solving Ability

    Science.gov (United States)

    Shadle, Susan E.; Brown, Eric C.; Towns, Marcy H.; Warner, Don L.

    2012-01-01

    The ability to couple problem solving both to the understanding of chemical concepts and to laboratory practices is an essential skill for undergraduate chemistry programs to foster in our students. Therefore, chemistry programs must offer opportunities to answer real problems that require use of problem-solving processes used by practicing…

  20. The Airlift Planning Problem

    Science.gov (United States)

    2017-01-02

    heuristic , which is a local search heuristic . We start with a partition S1, . . . , SA of the requirements, where Sa represents the requirements...in what order the aircraft will pickup and deliver its assigned requirements), using a combination of heuristics and column generation. Through...priority and short-notice missions. The planning of airlift missions is of critical importance to USTRANSCOM, for two reasons. First, due to the time

  1. The Elder Problem

    Directory of Open Access Journals (Sweden)

    John W. Elder

    2017-03-01

    Full Text Available This paper presents an autobiographical and biographical historical account of the genesis, evolution and resolution of the Elder Problem. It begins with John W. Elder and his autobiographical story leading to his groundbreaking work on natural convection at Cambridge in the 1960’s. His seminal work published in the Journal of Fluid Mechanics in 1967 became the basis for the modern benchmark of variable density flow simulators that we know today as “The Elder Problem”. There have been well known and major challenges with the Elder Problem model benchmark—notably the multiple solutions that were ultimately uncovered using different numerical models. Most recently, it has been shown that the multiple solutions are indeed physically realistic bifurcation solutions to the Elder Problem and not numerically spurious artefacts. The quandary of the Elder Problem has now been solved—a major scientific breakthrough for fluid mechanics and for numerical modelling. This paper—records, reflections, reminiscences, stories and anecdotes—is an historical autobiographical and biographical memoir. It is the personal story of the Elder Problem told by some of the key scientists who established and solved the Elder Problem. 2017 marks the 50 year anniversary of the classical work by John W. Elder published in Journal of Fluid Mechanics in 1967. This set the stage for this scientific story over some five decades. This paper is a celebration and commemoration of the life and times of John W. Elder, the problem named in his honour, and some of the key scientists who worked on, and ultimately solved, it.

  2. About some types of constraints in problems of routing

    Science.gov (United States)

    Petunin, A. A.; Polishuk, E. G.; Chentsov, A. G.; Chentsov, P. A.; Ukolov, S. S.

    2016-12-01

    Many routing problems arising in different applications can be interpreted as a discrete optimization problem with additional constraints. The latter include generalized travelling salesman problem (GTSP), to which task of tool routing for CNC thermal cutting machines is sometimes reduced. Technological requirements bound to thermal fields distribution during cutting process are of great importance when developing algorithms for this task solution. These requirements give rise to some specific constraints for GTSP. This paper provides a mathematical formulation for the problem of thermal fields calculating during metal sheet thermal cutting. Corresponding algorithm with its programmatic implementation is considered. The mathematical model allowing taking such constraints into account considering other routing problems is discussed either.

  3. Fuel handling problems at KANUPP

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, I; Mazhar Hasan, S; Mugtadir, A [Karachi Nuclear Power Plant (KANUPP), Karachi (Pakistan)

    1991-04-01

    KANUPP experienced two abnormal fuel and fuel handling related problems during the year 1990. One of these had arisen due to development of end plate to end plate coupling between the two bundles at the leading end of the fuel string in channel HO2-S. The incident occurred when attempts were being made to fuel this channel. Due to pulling of sticking bundles into the acceptor fuelling machine (north) magazine, which was not designed to accommodate two bundles, a magazine rotary stop occurred. The forward motion of the charge tube was simultaneously discovered to be restricted. The incident led to stalling of fuelling machine locked on to the channel HO2, necessitating a reactor shut down. Removal of the fuelling machine was accomplished sometime later after draining of the channel. The second incident which made the fuelling of channel KO5-N temporarily inexecutable, occurred during attempts to remove its north end shield plug when this channel came up for fuelling. The incident resulted due to breaking of the lugs of the shield plug, making its withdrawal impossible. The Plant however kept operating with suspended fuelling of channel KO5, until it could no longer sustain a further increase in fuel burnup at the maximum rating position. Resolving both these problems necessitated draining of the respective channels, leaving the resident fuel uncovered for the duration of the associated operation. Due to substantial difference in the oxidation temperatures Of UO{sub 2} and Zircaloy and its influence as such on the cooling requirement, it was necessary either to determine explicitly that the respective channels did not contain defective fuel bundles or wait for time long enough to allow the decay heat to reduce to manageable proportions. This had a significant bearing on the Plant down time necessary for the rectification of the problems. This paper describes the two incidents in detail and dwells upon the measures adopted to resolve the related problems. (author)

  4. Fuel handling problems at KANUPP

    International Nuclear Information System (INIS)

    Ahmed, I.; Mazhar Hasan, S.; Mugtadir, A.

    1991-01-01

    KANUPP experienced two abnormal fuel and fuel handling related problems during the year 1990. One of these had arisen due to development of end plate to end plate coupling between the two bundles at the leading end of the fuel string in channel HO2-S. The incident occurred when attempts were being made to fuel this channel. Due to pulling of sticking bundles into the acceptor fuelling machine (north) magazine, which was not designed to accommodate two bundles, a magazine rotary stop occurred. The forward motion of the charge tube was simultaneously discovered to be restricted. The incident led to stalling of fuelling machine locked on to the channel HO2, necessitating a reactor shut down. Removal of the fuelling machine was accomplished sometime later after draining of the channel. The second incident which made the fuelling of channel KO5-N temporarily inexecutable, occurred during attempts to remove its north end shield plug when this channel came up for fuelling. The incident resulted due to breaking of the lugs of the shield plug, making its withdrawal impossible. The Plant however kept operating with suspended fuelling of channel KO5, until it could no longer sustain a further increase in fuel burnup at the maximum rating position. Resolving both these problems necessitated draining of the respective channels, leaving the resident fuel uncovered for the duration of the associated operation. Due to substantial difference in the oxidation temperatures Of UO 2 and Zircaloy and its influence as such on the cooling requirement, it was necessary either to determine explicitly that the respective channels did not contain defective fuel bundles or wait for time long enough to allow the decay heat to reduce to manageable proportions. This had a significant bearing on the Plant down time necessary for the rectification of the problems. This paper describes the two incidents in detail and dwells upon the measures adopted to resolve the related problems. (author)

  5. Required reserves as a credit policy tool

    OpenAIRE

    Mimir, Yasin; Sunel, Enes; Taskin, Temel

    2012-01-01

    This paper conducts a quantitative investigation of the role of reserve requirements as a macroprudential policy tool. We build a monetary DSGE model with a banking sector in which (i) an agency problem between households and banks leads to endogenous capital constraints for banks in obtaining funds from households, (ii) banks are subject to time-varying reserve requirements that countercyclically respond to expected credit growth, (iii) households face cash-in-advance constraints, requiring ...

  6. Tart cherries improve working memory in aged rats

    Science.gov (United States)

    Aged rats show impaired performance on cognitive tasks that require the use of spatial learning and memory. In previous studies, we have shown the beneficial effects of various dark-colored berry fruits (blueberries, strawberries, and blackberries) in reversing age-related deficits in behavioral and...

  7. Acai fruit improves motor and cognitive function in aged rats

    Science.gov (United States)

    Aged rats show impaired performance on motor and cognitive tasks that require the use of spatial learning and memory. In previous studies, we have shown the beneficial effects of various berry fruits (blueberries, strawberries, and blackberries) in reversing age-related deficits in behavioral and ne...

  8. Feed tank transfer requirements

    International Nuclear Information System (INIS)

    Freeman-Pollard, J.R.

    1998-01-01

    This document presents a definition of tank turnover. Also, DOE and PC responsibilities; TWRS DST permitting requirements; TWRS Authorization Basis (AB) requirements; TWRS AP Tank Farm operational requirements; unreviewed safety question (USQ) requirements are presented for two cases (i.e., tank modifications occurring before tank turnover and tank modification occurring after tank turnover). Finally, records and reporting requirements, and documentation which will require revision in support of transferring a DST in AP Tank Farm to a privatization contractor are presented

  9. Feed tank transfer requirements

    Energy Technology Data Exchange (ETDEWEB)

    Freeman-Pollard, J.R.

    1998-09-16

    This document presents a definition of tank turnover. Also, DOE and PC responsibilities; TWRS DST permitting requirements; TWRS Authorization Basis (AB) requirements; TWRS AP Tank Farm operational requirements; unreviewed safety question (USQ) requirements are presented for two cases (i.e., tank modifications occurring before tank turnover and tank modification occurring after tank turnover). Finally, records and reporting requirements, and documentation which will require revision in support of transferring a DST in AP Tank Farm to a privatization contractor are presented.

  10. Anticoagulant resistance: a relevant issue in sewer rat (Rattus norvegicus) control?

    DEFF Research Database (Denmark)

    Heiberg, Ann-Charlotte

    2009-01-01

    the resistant rats, had resistance-related mutations in the VKORC1 gene. CONCLUSION: The results of this study suggest that the genetic background of anticoagulant resistance may have to be redefined in respect of resistance-related changes in the VKORC1 gene. Copyright © 2009 Society of Chemical Industry......BACKGROUND: The majority of rat problems in cities are thought to be related to defective sewers, and the use of anticoagulant rodenticides in such places is often implemented as part of regular urban rodent control. Knowledge pertaining to the resistance status of sewer rat populations is non......-existent, which may be leading to control problems in cities. It has become crucial to provide knowledge on the prevalence of resistance and how different control strategies have affected its prevalence among sewer rat populations. The prevalence of resistance was investigated in six sewer locations in Copenhagen...

  11. Development of a problem solving evaluation instrument; untangling of specific problem solving assets

    Science.gov (United States)

    Adams, Wendy Kristine

    The purpose of my research was to produce a problem solving evaluation tool for physics. To do this it was necessary to gain a thorough understanding of how students solve problems. Although physics educators highly value problem solving and have put extensive effort into understanding successful problem solving, there is currently no efficient way to evaluate problem solving skill. Attempts have been made in the past; however, knowledge of the principles required to solve the subject problem are so absolutely critical that they completely overshadow any other skills students may use when solving a problem. The work presented here is unique because the evaluation tool removes the requirement that the student already have a grasp of physics concepts. It is also unique because I picked a wide range of people and picked a wide range of tasks for evaluation. This is an important design feature that helps make things emerge more clearly. This dissertation includes an extensive literature review of problem solving in physics, math, education and cognitive science as well as descriptions of studies involving student use of interactive computer simulations, the design and validation of a beliefs about physics survey and finally the design of the problem solving evaluation tool. I have successfully developed and validated a problem solving evaluation tool that identifies 44 separate assets (skills) necessary for solving problems. Rigorous validation studies, including work with an independent interviewer, show these assets identified by this content-free evaluation tool are the same assets that students use to solve problems in mechanics and quantum mechanics. Understanding this set of component assets will help teachers and researchers address problem solving within the classroom.

  12. Alleviation in the rat of a GABA-induced reduction in food intake and growth.

    Science.gov (United States)

    Tews, J K; Repa, J J; Harper, A E

    1984-07-01

    Cold exposure and diet dilution which stimulate food intake of normal rats lessened depressions of food intake and growth induced by dietary GABA. During a 3-day adaptation to the cold, rats fed a diet containing 4.5% GABA lost weight; thereafter, food intake and growth rate differed little from those of cold control rats and were usually greater than those of normal rats fed GABA. Hepatic GABA-aminotransferase activity of cold-exposed rats fed the GABA diet increased to about twice that of normal control rats. Rats fed a control diet diluted by half with cellulose ate 50% more of this diet than of the undiluted diet but gained only 20% less weight. Rats ate twice as much of a diluted, 9% GABA diet as of an undiluted, 4.5% GABA diet (thus doubling their GABA intake) and gained three times as much weight. A novel food (condensed milk) barely lessened the adverse responses to GABA. These results show that conditions requiring rats to increase their food intake in order to maintain body weight can also increase their acceptance of a diet high in GABA.

  13. Solved problems in electromagnetics

    CERN Document Server

    Salazar Bloise, Félix; Bayón Rojo, Ana; Gascón Latasa, Francisco

    2017-01-01

    This book presents the fundamental concepts of electromagnetism through problems with a brief theoretical introduction at the beginning of each chapter. The present book has a strong  didactic character. It explains all the mathematical steps and the theoretical concepts connected with the development of the problem. It guides the reader to understand the employed procedures to learn to solve the exercises independently. The exercises are structured in a similar way: The chapters begin with easy problems increasing progressively in the level of difficulty. This book is written for students of physics and engineering in the framework of the new European Plans of Study for Bachelor and Master and also for tutors and lecturers. .

  14. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  15. Some Problems for Biolinguistics

    Directory of Open Access Journals (Sweden)

    Derek Bickerton

    2014-03-01

    Full Text Available Biolinguistics will have to face and resolve several problems before it can achieve a pivotal position in the human sciences. Its relationship to the Minimalist Program is ambiguous, creating doubts as to whether it is a genuine subdiscipline or merely another name for a particular linguistic theory. Equally ambiguous is the relationship it assumes between ‘knowledge of language’ and the neural mechanisms that actually construct sentences. The latter issue raises serious questions about the validity of covert syntactic operations. Further problems arise from the attitudes of many biolinguists towards natural selection and evo-devo: The first they misunderstand, the second they both misunderstand and overestimate. One consequence is a one-sided approach to language evolution crucially involving linguistic ‘precursors’ and the protolanguage hypothesis. Most of these problems arise through the identification of biolinguistics with internalist and essentialist approaches to language, thereby simultaneously narrowing its scope and hindering its acceptance by biologists.

  16. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

  17. Computational problems in engineering

    CERN Document Server

    Mladenov, Valeri

    2014-01-01

    This book provides readers with modern computational techniques for solving variety of problems from electrical, mechanical, civil and chemical engineering. Mathematical methods are presented in a unified manner, so they can be applied consistently to problems in applied electromagnetics, strength of materials, fluid mechanics, heat and mass transfer, environmental engineering, biomedical engineering, signal processing, automatic control and more.   • Features contributions from distinguished researchers on significant aspects of current numerical methods and computational mathematics; • Presents actual results and innovative methods that provide numerical solutions, while minimizing computing times; • Includes new and advanced methods and modern variations of known techniques that can solve difficult scientific problems efficiently.  

  18. Distributed Problem-Solving

    DEFF Research Database (Denmark)

    Chemi, Tatiana

    2016-01-01

    This chapter aims to deconstruct some persistent myths about creativity: the myth of individualism and of the genius. By looking at literature that approaches creativity as a participatory and distributed phenomenon and by bringing empirical evidence from artists’ studios, the author presents a p......, what can educators at higher education learn from the ways creative groups solve problems? How can artists contribute to inspiring higher education?......This chapter aims to deconstruct some persistent myths about creativity: the myth of individualism and of the genius. By looking at literature that approaches creativity as a participatory and distributed phenomenon and by bringing empirical evidence from artists’ studios, the author presents...... a perspective that is relevant to higher education. The focus here is on how artists solve problems in distributed paths, and on the elements of creative collaboration. Creative problem-solving will be looked at as an ongoing dialogue that artists engage with themselves, with others, with recipients...

  19. Integrating Multimedia and Physics Problems

    Science.gov (United States)

    Titus, Aaron P.

    1997-11-01

    Although expert problem solvers typically use pictorial representations when solving problems, novices tend to proceed from the given problem statement to a mathematical solution without first developing a visual representation of the problem. For this reason, multimedia may be an effective tool to enhance students' success at solving problems. However, merely presenting a video of motion described in a problem is not necessarily the most effective method as was found in a recent study of students' responses on Web-based homework questions. Rather, multimedia-focused problems, where data relevant to solving the problem is embedded in a video or animation, may be the best use of multimedia in problem solving. Examples of multimedia-enhanced problems and multimedia-focused problems will be demonstrated, and their differences from "traditional" problems will be highlighted. Recommendations on the use of multimedia with problem solving and preliminary data on students' success at solving these problems will be discussed.

  20. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av

  1. Advanced calculus problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of advanced calculus currently av

  2. Problems over Information Systems

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    The problems of estimation of the minimum average time complexity of decision trees and design of efficient algorithms are complex in general case. The upper bounds described in Chap. 2.4.3 can not be applied directly due to large computational complexity of the parameter M(z). Under reasonable assumptions about the relation of P and NP, there are no polynomial time algorithms with good approximation ratio [12, 32]. One of the possible solutions is to consider particular classes of problems and improve the existing results using characteristics of the considered classes. © Springer-Verlag Berlin Heidelberg 2011.

  3. Solving Environmental Problems

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph

    2017-01-01

    for Research and Technological Development (FP7), our results indicate that the problem-solving potential of a search strategy increases with the diversity of existing knowledge of the partners in a consortium and with the experience of the partners involved. Moreover, we identify a substantial negative effect...... dispersed. Hence, firms need to collaborate. We shed new light on collaborative search strategies led by firms in general and for solving environmental problems in particular. Both topics are largely absent in the extant open innovation literature. Using data from the European Seventh Framework Program...

  4. The Problem Revisited

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2015-01-01

    Problem-based learning (PBL) is becoming increasingly popular in design educations, but how is it taught and practiced? This paper presents a case study of a three-day workshop that has the purpose of introducing PBL to design students. A theoretical background on PBL and problems in design is es...... is established and is backing up the case study. The study shows that design engineering and architectural students without experience in PBL in general finds the approach to be beneficial when working on a design challenge in a student team....

  5. Calculus problems and solutions

    CERN Document Server

    Ginzburg, Abraham

    2011-01-01

    Ideal for self-instruction as well as for classroom use, this text helps students improve their understanding and problem-solving skills in analysis, analytic geometry, and higher algebra. More than 1,200 problems appear in the text, with concise explanations of the basic notions and theorems to be used in their solution. Many are followed by complete answers; solutions for the others appear at the end of the book. Topics include sequences, functions of a single variable, limit of a function, differential calculus for functions of a single variable, fundamental theorems and applications of dif

  6. [Medical problems of musicians].

    Science.gov (United States)

    van de Wiel, Albert; Rietveld, Boni

    2010-01-01

    Most individuals enjoy making music, but pleasure may be diminished by physical complaints. The most common complaints in musicians include injuries of the upper part of the body including the shoulder and spine, skin disorders and hearing problems. Injuries are not so much related to the extent of rehearsing and playing but are mostly the result of a wrong position and misuse of the instrument. Adequate preparation before playing and professional coaching to avoid injuries or to detect problems at an early stage are exceptions rather than the rule. Because of the large number of amateur and professional musicians in the Netherlands, music medicine deserves a more prominent role.

  7. Classic Problems of Probability

    CERN Document Server

    Gorroochurn, Prakash

    2012-01-01

    "A great book, one that I will certainly add to my personal library."—Paul J. Nahin, Professor Emeritus of Electrical Engineering, University of New Hampshire Classic Problems of Probability presents a lively account of the most intriguing aspects of statistics. The book features a large collection of more than thirty classic probability problems which have been carefully selected for their interesting history, the way they have shaped the field, and their counterintuitive nature. From Cardano's 1564 Games of Chance to Jacob Bernoulli's 1713 Golden Theorem to Parrondo's 1996 Perplexin

  8. Special problems: LBB, thermal effects

    International Nuclear Information System (INIS)

    Lin Chiwen

    2001-01-01

    This section presents the discussion of special problems in the reactor coolant system design, including LBB and thermal effects. First, the categories of fracture mechanics technology applicable to LBB is discussed. Two categories of fracture mechanics, namely: linear-elastic fracture mechanics (LEFM) and elastic-plastic fracture mechanics (EPFM) are discussed specifically. Next, basic concepts of LEFM are discussed. This will be followed by a discussion of EPFM, with more specific discussion of the methodology currently acceptable to NRC, with the emphasis on the J-integral approach. This is followed by a discussion of the NRC position and recommendations and basic requirements laid out by NRC. A specific example of LBB application to WPWR piping is used to identify the key steps to be followed, in order to satisfy the recommendations and requirements of NRC. An application of LBB to the WPWR reactor coolant loop piping is provided as further illustration of the methodology. This section focuses on the thermal effects which have not been addressed earlier, and the thermal effects which have caused particular concerns on potential reactor degradations, such as pressurized thermal shocks. The organization of this section is divided into the following subsections: linear-elastic fracture mechanics (LEFM); elastic-plastic fracture mechanics (EPFM); J concepts; NRC recommendations and requirements on the application of LBB; two specific applications of LBB to WPWR piping; PWR internals degradation; thermal fatigue considerations; a case study of pressurized thermal shock

  9. Toward Solving the Problem of Problem Solving: An Analysis Framework

    Science.gov (United States)

    Roesler, Rebecca A.

    2016-01-01

    Teaching is replete with problem solving. Problem solving as a skill, however, is seldom addressed directly within music teacher education curricula, and research in music education has not examined problem solving systematically. A framework detailing problem-solving component skills would provide a needed foundation. I observed problem solving…

  10. Laughing rats are optimistic.

    Directory of Open Access Journals (Sweden)

    Rafal Rygula

    Full Text Available Emotions can bias human decisions- for example depressed or anxious people tend to make pessimistic judgements while those in positive affective states are often more optimistic. Several studies have reported that affect contingent judgement biases can also be produced in animals. The animals, however, cannot self-report; therefore, the valence of their emotions, to date, could only be assumed. Here we present the results of an experiment where the affect-contingent judgement bias has been produced by objectively measured positive emotions. We trained rats in operant Skinner boxes to press one lever in response to one tone to receive a food reward and to press another lever in response to a different tone to avoid punishment by electric foot shock. After attaining a stable level of discrimination performance, the animals were subjected to either handling or playful, experimenter-administered manual stimulation - tickling. This procedure has been confirmed to induce a positive affective state in rats, and the 50-kHz ultrasonic vocalisations (rat laughter emitted by animals in response to tickling have been postulated to index positive emotions akin to human joy. During the tickling and handling sessions, the numbers of emitted high-frequency 50-kHz calls were scored. Immediately after tickling or handling, the animals were tested for their responses to a tone of intermediate frequency, and the pattern of their responses to this ambiguous cue was taken as an indicator of the animals' optimism. Our findings indicate that tickling induced positive emotions which are directly indexed in rats by laughter, can make animals more optimistic. We demonstrate for the first time a link between the directly measured positive affective state and decision making under uncertainty in an animal model. We also introduce innovative tandem-approach for studying emotional-cognitive interplay in animals, which may be of great value for understanding the emotional

  11. Renormalization-group approach to nonlinear radiation-transport problems

    International Nuclear Information System (INIS)

    Chapline, G.F.

    1980-01-01

    A Monte Carlo method is derived for solving nonlinear radiation-transport problems that allows one to average over the effects of many photon absorptions and emissions at frequencies where the opacity is large. This method should allow one to treat radiation-transport problems with large optical depths, e.g., line-transport problems, with little increase in computational effort over that which is required for optically thin problems

  12. Effects of herbal ointment containing the leaf extracts of Madeira vine (Anredera cordifolia (Ten.) Steenis) for burn wound healing process on albino rats.

    Science.gov (United States)

    Yuniarti, Wiwik Misaco; Lukiswanto, Bambang Sektiari

    2017-07-01

    Skin burn is a health problem that requires fast and accurate treatment. If not well-treated, the burn will cause various damaging conditions for the patient. The leaf extract of Madeira vine ( Anredera cordifolia (Ten.) Steenis), or popularly known as Binahong in Indonesia, has been used to treat various diseases. The purpose of this research is to determine the effects of leaf extracts of Madeira vine ( A. cordifolia (Ten.) Steenis) on skin burn healing process in rats as an animal model. In this research, there were four treatment groups: G0, G1, G2, and G3, each consisting of five rats. All these rats were given skin burns, using hot metal plates. Then, sulfadiazine was given to G0, 2.5% leaf extract of Madeira vine was given to G1, 5% extract was given to G2, and 10% extract was given to G3, for straight 14 days topically, 3 times a day. At the end of the treatment period, skin excisions were conducted, and histopathological examination was carried out. Microscopic observation on the wound healing process on the collagen deposition, polymorphonuclear infiltration, angiogenesis, and fibrosis showed that G2 had a significant difference with G0, G1, and G3 (pMadeira vine, which have the antioxidant, anti-inflammatory, and antibacterial effects. The ointment from the 5% leaf extract of Madeira vine ( A. cordifolia (Ten.) Steenis) has been proven to be effective to be used for topical burn therapy.

  13. NURSING AND ITS PROBLEMS*

    African Journals Online (AJOL)

    1971-07-10

    Jul 10, 1971 ... not enough stress was laid on the exceedingly importa~t part played by the nursing staff .... trained to take more of the load off the sister, and on the other hand the sister should .... a world problem. Employment of Nurse Aides.

  14. The Caterer's Problem.

    Science.gov (United States)

    Krause, Eugene F.

    1983-01-01

    An approach to teaching problem solving to preservice and in-service middle school teachers is described. They examined an unsolved question as a class research project. The process of developing the solution is detailed, and difficulties contained within the process are noted. (MP)

  15. Introspection in Problem Solving

    Science.gov (United States)

    Jäkel, Frank; Schreiber, Cornell

    2013-01-01

    Problem solving research has encountered an impasse. Since the seminal work of Newell und Simon (1972) researchers do not seem to have made much theoretical progress (Batchelder and Alexander, 2012; Ohlsson, 2012). In this paper we argue that one factor that is holding back the field is the widespread rejection of introspection among cognitive…

  16. Problem Solving in Practice

    Science.gov (United States)

    Greene, Kim; Heyck-Williams, Jeff; Timpson Gray, Elicia

    2017-01-01

    Problem solving spans all grade levels and content areas, as evidenced by this compilation of projects from schools across the United States. In one project, high school girls built a solar-powered tent to serve their city's homeless population. In another project, 4th graders explored historic Jamestown to learn about the voices lost to history.…

  17. Target reactor development problems

    International Nuclear Information System (INIS)

    Lathrop, K.D.; Vigil, J.C.

    1977-01-01

    Target-blanket design studies are discussed for an accelerator-breeder concept employing a linear accelerator in conjunction with a modified conventional power reactor to produce both fissile fuel and power. The following problems in target and blanket system design are discussed: radiation damage, heat removal, neutronic design, and economics

  18. A Geometric Dissection Problem

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 7. A Geometric Dissection Problem. M N Deshpande. Think It Over Volume 7 Issue 7 July 2002 pp 91-91. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/007/07/0091-0091. Author Affiliations.

  19. Microbiological problems in radiosterilization

    International Nuclear Information System (INIS)

    Czerniawski, E.

    1997-01-01

    Microbiological problems connected with radiosterilization of medical materials, pharmaceuticals and cosmetics have been discussed in detail. Dose-response relationship for different bacteria has been shown. Recommended sterilization and postirradiation control procedures have been described. 24 refs, 6 figs, 5 tabs

  20. Multiobjective suspension control problem

    NARCIS (Netherlands)

    Jager, de A.G.

    1995-01-01

    The paper describes a (controller) design problem in the field of suspension systems for transport vehicles. A ten degrees-of-freedom model for a tractor-semitrailer vehicle is presented, using parameters derived from a real vehicle, which should be used for design and verification purposes. Road

  1. Catastrophes control problem

    International Nuclear Information System (INIS)

    Velichenko, V.V.

    1994-01-01

    The problem of catastrophe control is discussed. Catastrophe control aims to withdraw responsible engineering constructions out of the catastrophe. The mathematical framework of catastrophes control systems is constructed. It determines the principles of systems filling by the concrete physical contents and, simultaneously, permits to employ modern control methods for the synthesis of optimal withdrawal strategy for protected objects

  2. Unfolding a Problem

    Science.gov (United States)

    Currier, Sarah Cox

    2015-01-01

    In this article, Sarah Currier, a math specialist at Elizabeth Hall International School in Minnesota, describes how she used origami in a deliberate manner to teach content. She shares how she uses paper folding to teach mathematical concepts, reinforce vocabulary, and as a problem-solving model. She also offers ideas for using origami in other…

  3. The solar neutrino problem

    Indian Academy of Sciences (India)

    to a research problem that now commands the attention of a large number of physicists ... the first comparison between theory and experiment was made. .... prior probability assigned to hypothesis А. The integration in the denominator is .... The key feature of figure 5, which is well known, is the marked reduction in the Be.

  4. Problem-based learning

    NARCIS (Netherlands)

    Loyens, Sofie; Kirschner, Paul A.; Paas, Fred

    2010-01-01

    Loyens, S. M. M., Kirschner, P. A., & Paas, F. (2011). Problem-based learning. In S. Graham (Editor-in-Chief), A. Bus, S. Major, & L. Swanson (Associate Editors), APA educational psychology handbook: Vol. 3. Application to learning and teaching (pp. 403-425). Washington, DC: American Psychological

  5. "Righting" the Writing Problem.

    Science.gov (United States)

    Shaughnessy, Michael F.; Eastham, Nicholas

    The problem of college students' writing skills or lack thereof is generally agreed upon in academia. One cause is the inordinate amount of multiple choice/true false/fill in the blank type of tests that students take in high school and college. Not only is there is a dearth of actual classes in writing available, few students recognize the need…

  6. The Bycatch Problem

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 5. The Bycatch Problem - Effects of Commercial Fisheries on Non-Target Species in India. Aaron Savio Lobo. General Article Volume 12 Issue 5 May 2007 pp 60-70 ...

  7. The Problem of Consciousness.

    Science.gov (United States)

    Crick, Francis; Koch, Christof

    1992-01-01

    Discusses approaches to the problem presented in understanding consciousness as a yet undiscovered process of interacting neuron activity. Presents the historical context of research in the area of human awareness and identifies research necessary to scientifically explain how the brain relates to the mind. (MCO)

  8. Dynamical impurity problems

    International Nuclear Information System (INIS)

    Emery, V.J.; Kivelson, S.A.

    1993-01-01

    In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class

  9. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  10. Problem Patron Manual.

    Science.gov (United States)

    Brown, Marion, Comp.; And Others

    This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…

  11. Problems in photoradiation effects

    International Nuclear Information System (INIS)

    Milinchuk, V.K.

    1986-01-01

    This paper discusses the most interesting photoradiation effects observed in recent years and directs attention to problems whose solution has a bearing on progress in photoradiation chemistry, and which also are significant for divisions of modern physical chemistry such as the kinetics and mechanisms of elementary processes in solid organic materials, the radiation resistance of organic materials, and aging in polymers

  12. Dynamical impurity problems

    Energy Technology Data Exchange (ETDEWEB)

    Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics

    1993-12-31

    In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.

  13. Puberty menorrhagia Requiring Inpatient Admission

    Directory of Open Access Journals (Sweden)

    AH Khosla

    2010-06-01

    Full Text Available INTRODUCTION: Puberty menorrhagia is a significant health problem in adolescent age group and severe cases may require admission and blood transfusion. Aim of this study was to evaluate the causes, associated complications and management of puberty menorrhagia. METHODS: Hospital records of all patients of puberty menorrhagia requiring admission were analyzed for etiology, duration since menarche, duration of bleeding, investigation profile and management. RESULTS: There were 18 patients of puberty menorrhagia requiring hospital admission. Etiology was anovulatory bleeding in 11 patients, bleeding disorders in five which included idiopathic thrombocytopenia purpura in three and one each with Von-Willebrand disease and leukemia. Two patients had hypothyroidism as the cause. Fourteen patients presented with severe anaemia and required blood transfusion. All except one responded to oral hormonal therapy. CONCLUSIONS: Puberty menorrhagia can be associated with severe complications and requiring blood transfusion. Although most common cause is anovulation but bleeding disorder, other medical condition and other organic causes must be ruled out in any patient of Puberty menorrhagia. KEYWORDS: anovulation, bleeding disorder, puberty, menorrhagia, anaemia.

  14. Young Children's Drawings in Problem Solving

    Science.gov (United States)

    Bakar, Kamariah Abu; Way, Jennifer; Bobis, Janette

    2016-01-01

    This paper explores young children's drawings (6 years old) in early number and addition activities in Malaysia. Observation, informal interviews and analysis of drawings revealed two types of drawing, and gave insight into the transitional process required for children to utilise drawings in problem solving. We argue the importance of valuing and…

  15. Geodesy problems in nuclear power plant construction

    International Nuclear Information System (INIS)

    Eory, K.

    1981-01-01

    The special geodetic problems encountered during the construction of the Paks nuclear power plants are treated. The main building with its hermetically connected components including the reactor, the steam generators, the circulation pumps etc. impose special requirements on the control net of datum points. The geodesy tasks solved during the construction of the main building are presented in details. (R.P.)

  16. An analysis of shift class design problems

    NARCIS (Netherlands)

    L.G. Kroon (Leo); A.W.J. Kolen

    1994-01-01

    textabstractIn this paper we consider a generalization of the Fixed Job Schedule Problem (FJSP) which appears in the aircraft maintenance process at an airport. A number of jobs must be carried out where each job requires processing from a fixed time to a fixed finish time. These jobs must be

  17. Employment and Training Problems in New Factories.

    Science.gov (United States)

    International Labour Office, Geneva (Switzerland).

    Does management in newly established factories using highly advanced technology meet special problems in recruitment and training of their workers? Are the traditional training systems supplying the skilled manpower required for running highly sophisticated plants? These were the basic questions asked when the present study was started in seven…

  18. Optimal Wafer Cutting in Shuttle Layout Problems

    DEFF Research Database (Denmark)

    Nisted, Lasse; Pisinger, David; Altman, Avri

    2011-01-01

    . The shuttle layout problem is frequently solved in two phases: first, a floorplan of the shuttle is generated. Then, a cutting plan is found which minimizes the overall number of wafers needed to satisfy the demand of each die type. Since some die types require special production technologies, only compatible...

  19. Engaged Problem Formulation in IS Research

    DEFF Research Database (Denmark)

    Nielsen, Peter Axel; Persson, John Stouby

    2016-01-01

    “Is this the problem?”: the question that haunts many information systems (IS) researchers when they pursue work relevant to both practice and research. Nevertheless, a deliberate answer to this question requires more than simply asking the involved IS practitioners. Deliberately formulating...

  20. An introduction to the dark energy problem

    Science.gov (United States)

    Dobado, Antonio; Maroto, Antonio L.

    2009-04-01

    In this work we review briefly the origin and history of the cosmological constant and its recent reincarnation in the form of the dark energy component of the universe. We also comment on the fundamental problems associated to its existence and magnitude which require an urgent solution for the sake of the internal consistency of theoretical physics.

  1. Multifield methods for nuclear thermohydraulics problems

    International Nuclear Information System (INIS)

    Banerjee, S.

    1987-01-01

    The multifield model, in which separate sets of conservation equations are written for each phase, or clearly identifiable portions of a phase, is derived by averaging the local instantaneous equations. The closure relationships required to replace information lost in the averaging process are discussed. The mathematical structure of the model is considered and it is shown that application to a variety of problems in which the phases are well separated leads to good predictions of experimental data. For problems in which the phases are more closely coupled, the model is more difficult to apply correctly. However, careful consideration of interfield momentum and heat transfer is shown to give excellent results for some complex problems like density wave propagation in bubbly flows. The model in its present form is shown to be less useful for highly intermittent regimes like slug and churn flows. Data on a reflux condensation situation near the flooding point are discussed to indicate directions in which further work is required

  2. ASCR Science Network Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Dart, Eli; Tierney, Brian

    2009-08-24

    performance networks is a consistent, widely deployed, well-maintained toolset that is optimized for wide area, high-speed data transfer (e.g. GridFTP) that allows scientists to easily utilize the services and capabilities that the network provides. Network test and measurement is an important part of ensuring that these tools and network services are functioning correctly. One example of a tool in this area is the recently developed perfSONAR, which has already shown its usefulness in fault diagnosis during the recent deployment of high-performance data movers at NERSC and ORNL. On the other hand, it is clear that there is significant work to be done in the area of authentication and access control - there are currently compatibility problems and differing requirements between the authentication systems in use at different facilities, and the policies and mechanisms in use at different facilities are sometimes in conflict. Finally, long-term software maintenance was of concern for many attendees. Scientists rely heavily on a large deployed base of software that does not have secure programmatic funding. Software packages for which this is true include data transfer tools such as GridFTP as well as identity management and other software infrastructure that forms a critical part of the Open Science Grid and the Earth System Grid.

  3. Students’ Mathematical Problem-Solving Abilities Through The Application of Learning Models Problem Based Learning

    Science.gov (United States)

    Nasution, M. L.; Yerizon, Y.; Gusmiyanti, R.

    2018-04-01

    One of the purpose mathematic learning is to develop problem solving abilities. Problem solving is obtained through experience in questioning non-routine. Improving students’ mathematical problem-solving abilities required an appropriate strategy in learning activities one of them is models problem based learning (PBL). Thus, the purpose of this research is to determine whether the problem solving abilities of mathematical students’ who learn to use PBL better than on the ability of students’ mathematical problem solving by applying conventional learning. This research included quasi experiment with static group design and population is students class XI MIA SMAN 1 Lubuk Alung. Class experiment in the class XI MIA 5 and class control in the class XI MIA 6. The instrument of final test students’ mathematical problem solving used essay form. The result of data final test in analyzed with t-test. The result is students’ mathematical problem solving abilities with PBL better then on the ability of students’ mathematical problem solving by applying conventional learning. It’s seen from the high percentage achieved by the group of students who learn to use PBL for each indicator of students’ mathematical problem solving.

  4. The Effect of Problem Solving and Problem Posing Models and Innate Ability to Students Achievement

    Directory of Open Access Journals (Sweden)

    Ratna Kartika Irawati

    2015-04-01

    Full Text Available Pengaruh Model Problem Solving dan Problem Posing serta Kemampuan Awal terhadap Hasil Belajar Siswa   Abstract: Chemistry concepts understanding features abstract quality and requires higher order thinking skills. Yet, the learning on chemistry has not boost the higher order thinking skills of the students. The use of the learning model of Problem Solving and Problem Posing in observing the innate ability of the student is expected to resolve the issue. This study aims to determine the learning model which is effective to improve the study of the student with different level of innate ability. This study used the quasi-experimental design. The research data used in this research is the quiz/test of the class which consist of 14 multiple choice questions and 5 essay questions. The data analysis used is ANOVA Two Ways. The results showed that Problem Posing is more effective to improve the student compared to Problem Solving, students with high level of innate ability have better outcomes in learning rather than the students with low level of innate ability after being applied with the Problem solving and Problem posing model, further, Problem Solving and Problem Posing is more suitable to be applied to the students with high level of innate ability. Key Words: problem solving, problem posing, higher order thinking skills, innate ability, learning outcomes   Abstrak: Pemahaman konsep-konsep kimia yang bersifat abstrak membutuhkan keterampilan berpikir tingkat tinggi. Pembelajaran kimia belum mendorong siswa melakukan keterampilan berpikir tingkat tinggi. Penggunaan model pembelajaran Problem Solving dan Problem Posing dengan memperhatikan kemampuan awal siswa diduga dapat mengatasi masalah tersebut. Penelitian ini bertujuan untuk mengetahui model pembelajaran yang efektif dalam meningkatkan hasil belajar dengan kemampuan awal siswa yang berbeda. Penelitian ini menggunakan rancangan eksperimen semu. Data penelitian menggunakan tes hasil belajar

  5. Muon problem in UHECR investigations

    International Nuclear Information System (INIS)

    Petrukhin, A A; Bogdanov, A G; Kokoulin, R P

    2013-01-01

    In many UHECR experiments, some excess of muons is observed, which cannot be explained in frame of the existing theoretical models of hadron interaction. Attempts of its explanation through a heavy mass composition of PCR contradict the results of X max measurements. Really, the excess of muons appears already at lower energies (10 16 − 10 17 eV), but in this domain it may be explained by the trend to a heavier mass composition, which is in a qualitative agreement with the galactic model of CR origin. The absence of heavy nuclei at energies of the order of 10 18 eV requires to consider other possibilities of the appearance of muon excess, including changes of hadron interaction model. The actuality of the considered problem is connected with plans of future experiments in UHECR physics, in which the necessity of its solution must be taken into account.

  6. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  7. Nuclear insurance problems in Spain

    International Nuclear Information System (INIS)

    Gomez del Campo, Julian.

    1977-01-01

    The purpose of this paper is to study the problems raised in Spain by third party liability insurance for nuclear damage. National law in this field is based on the Paris Convention on nuclear third party liability and defines the conditions of liability of operators of nuclear installations. The insurance contract requirements must comply with the regulations on cover for nuclear risks, under the control of the Finance Ministry's competent services. Certain exceptional nuclear risks which cannot be covered entirely by ordinary insurance policies, are taken over by the Consorcio de Compensacion de Seguros which belongs to this Ministry. From the insurance viewpoint, the regulations make a distinction between nuclear and radioactive installations and nuclear transport. (NEA) [fr

  8. BOOK REVIEW: Inverse Problems. Activities for Undergraduates

    Science.gov (United States)

    Yamamoto, Masahiro

    2003-06-01

    into the nature of inverse problems and the appropriate mode of thought, chapter 1 offers historical vignettes, most of which have played an essential role in the development of natural science. These vignettes cover the first successful application of `non-destructive testing' by Archimedes (page 4) via Newton's laws of motion up to literary tomography, and readers will be able to enjoy a wide overview of inverse problems. Therefore, as the author asks, the reader should not skip this chapter. This may not be hard to do, since the headings of the sections are quite intriguing (`Archimedes' Bath', `Another World', `Got the Time?', `Head Games', etc). The author embarks on the technical approach to inverse problems in chapter 2. He has elegantly designed each section with a guide specifying course level, objective, mathematical and scientifical background and appropriate technology (e.g. types of calculators required). The guides are designed such that teachers may be able to construct effective and attractive courses by themselves. The book is not intended to offer one rigidly determined course, but should be used flexibly and independently according to the situation. Moreover, every section closes with activities which can be chosen according to the students' interests and levels of ability. Some of these exercises do not have ready solutions, but require long-term study, so readers are not required to solve all of them. After chapter 5, which contains discrete inverse problems such as the algebraic reconstruction technique and the Backus - Gilbert method, there are answers and commentaries to the activities. Finally, scripts in MATLAB are attached, although they can also be downloaded from the author's web page (http://math.uc.edu/~groetsch/). This book is aimed at students but it will be very valuable to researchers wishing to retain a wide overview of inverse problems in the midst of busy research activities. A Japanese version was published in 2002.

  9. The Effect of Nicotine Administration on Physical and Psychological Signs of Withdrawal Syndrome Induced by Single or Frequent Doses of Morphine in Rats

    OpenAIRE

    Mohammad Allahtavakoli; Fatemeh Amin; Elham Hakimizadeh; Ali Roohbakhsh; Sayed Ali Haeri Rohani; Ahmad Taghavi Rafsanjani; Abbas Haghparast; Ali Shamsizadeh

    2012-01-01

    Introduction. Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Materials and methods. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later t...

  10. Daily Access to Sucrose Impairs Aspects of Spatial Memory Tasks Reliant on Pattern Separation and Neural Proliferation in Rats

    Science.gov (United States)

    Reichelt, Amy C.; Morris, Margaret J.; Westbrook, Reginald Frederick

    2016-01-01

    High sugar diets reduce hippocampal neurogenesis, which is required for minimizing interference between memories, a process that involves "pattern separation." We provided rats with 2 h daily access to a sucrose solution for 28 d and assessed their performance on a spatial memory task. Sucrose consuming rats discriminated between objects…

  11. Long-term Western diet fed apolipoprotein E-deficient rats exhibit only modest early atherosclerotic characteristics

    DEFF Research Database (Denmark)

    Rune, Ida; Rolin, Bidda; Lykkesfeldt, Jens

    2018-01-01

    In the apolipoprotein E-deficient mouse, the gut microbiota has an impact on the development of atherosclerosis, but whether such correlations are also present in rats requires investigation. Therefore, we studied female SD-Apoe tm1sage (Apoe -/-) rats fed either a Western diet or a low-fat control...

  12. Genetics problem solving and worldview

    Science.gov (United States)

    Dale, Esther

    The research goal was to determine whether worldview relates to traditional and real-world genetics problem solving. Traditionally, scientific literacy emphasized content knowledge alone because it was sufficient to solve traditional problems. The contemporary definition of scientific literacy is, "The knowledge and understanding of scientific concepts and processes required for personal decision-making, participation in civic and cultural affairs and economic productivity" (NRC, 1996). An expanded definition of scientific literacy is needed to solve socioscientific issues (SSI), complex social issues with conceptual, procedural, or technological associations with science. Teaching content knowledge alone assumes that students will find the scientific explanation of a phenomenon to be superior to a non-science explanation. Formal science and everyday ways of thinking about science are two different cultures (Palmer, 1999). Students address this rift with cognitive apartheid, the boxing away of science knowledge from other types of knowledge (Jedege & Aikenhead, 1999). By addressing worldview, cognitive apartheid may decrease and scientific literacy may increase. Introductory biology students at the University of Minnesota during fall semester 2005 completed a written questionnaire-including a genetics content-knowledge test, four genetic dilemmas, the Worldview Assessment Instrument (WAI) and some items about demographics and religiosity. Six students responded to the interview protocol. Based on statistical analysis and interview data, this study concluded the following: (1) Worldview, in the form of metaphysics, relates to solving traditional genetic dilemmas. (2) Worldview, in the form of agency, relates to solving traditional genetics problems. (3) Thus, worldview must be addressed in curriculum, instruction, and assessment.

  13. Indoor air problems in Asia

    International Nuclear Information System (INIS)

    Leslie, G.B.

    1995-01-01

    Respiratory disease and mortality due to indoor air pollution are amongst the greatest environmental threats to health in the developing countries of Asia. World-wide, acute respiratory infection is the cause of death of at least 5 million children under the age of 5 every year. The World Bank has claimed that smoke from biomass fuels resulted in an estimated 4 million deaths annually amongst infants and children. Most of these deaths occur in developing countries. Combustion in its various forms must head the list of pollution sources in Asia. Combustion of various fuels for domestic heating, lighting and cooking comprises the major source of internally generated pollutants and combustion in industrial plants, power generation and transportation is the major cause of externally generated pollutants. The products of pyrolysis and combustion include many compounds with well-known adverse health effects. These include gases such as CO, CO 2 , NO x and SO 2 , volatile organic compounds such as polynuclear aromatic hydrocarbons and nitroamines as well as respirable particulates of variable composition. The nature and magnitude of the health risks posed by these materials vary with season, climate, location housing, method of ventilation, culture and socio-economic status. The most important cause of lung cancer in non-smokers in Northern Asia is the domestic combustion of smoky coal. Acute carbon monoxide poisoning is common in many Asian countries. Roads traffic exhaust pollution is worse in the major cities of South East Asia than almost anywhere else in the world and this externally generated air pollution forms the indoor air for the urban poor. Despite all these major problems there has been a tendency for international agencies to focus attention and resources on the more trivial problems of indoor air encountered in the affluent countries of the West. Regulatory agencies in Asia have been too frequently persuaded that their problems of indoor air pollution are

  14. Sales plan generation problem on TV broadcasting

    Directory of Open Access Journals (Sweden)

    Özlem Cosgun

    2016-07-01

    Full Text Available Major advertisers and/or advertisement agencies purchase hundreds of slots during a given broadcast period. Deterministic optimization approaches have been well developed for the problem of meeting client requests. The challenging task for the academic research currently is to address optimization problem under uncertainty. This paper is concerned with the sales plan generation problem when the audience levels of advertisement slots are random variables with known probability distributions. There are several constraints the TV networks must meet including client budget, product category and demographic information, plan weighting by week, program mix requirements, and the lengths of advertisement slots desired by the client. We formulate the problem as a chance constrained goal program and we demonstrate that it provides a robust solution with a user specified level of reliability.

  15. International young physicists' tournament problems & solutions 2014

    CERN Document Server

    Gao, Wenli

    2016-01-01

    International Young Physicists' Tournament (Iypt), is one of the most prestigious international physics contests among high school students. This book is based on the solutions of 2014 Iypt problems. The authors are undergraduate students who participated in the Cupt (Chinese Undergraduate Physics Tournament). It is intended as a college level solution to the challenging open-ended problems. It provides original, quantitative solutions in fulfilling seemingly impossible tasks. This book is not limited to the tasks required by the problems and it is not confined to the models and methods in present literatures. Many of the articles include modification and extension to existing models in references, or derivation and computation based on fundamental physics. This book provides quantitative solutions to practical problems in everyday life. This is a good reference book for undergraduates, advanced high-school students, physics educators and curious public interested in the intriguing phenomena in daily life.

  16. Argonne Code Center: benchmark problem book

    International Nuclear Information System (INIS)

    1977-06-01

    This report is a supplement to the original report, published in 1968, as revised. The Benchmark Problem Book is intended to serve as a source book of solutions to mathematically well-defined problems for which either analytical or very accurate approximate solutions are known. This supplement contains problems in eight new areas: two-dimensional (R-z) reactor model; multidimensional (Hex-z) HTGR model; PWR thermal hydraulics--flow between two channels with different heat fluxes; multidimensional (x-y-z) LWR model; neutron transport in a cylindrical ''black'' rod; neutron transport in a BWR rod bundle; multidimensional (x-y-z) BWR model; and neutronic depletion benchmark problems. This supplement contains only the additional pages and those requiring modification

  17. Incentive compatibility in kidney exchange problems.

    Science.gov (United States)

    Villa, Silvia; Patrone, Fioravante

    2009-12-01

    The problem of kidney exchanges shares common features with the classical problem of exchange of indivisible goods studied in the mechanism design literature, while presenting additional constraints on the size of feasible exchanges. The solution of a kidney exchange problem can be summarized in a mapping from the relevant underlying characteristics of the players (patients and their donors) to the set of matchings. The goal is to select only matchings maximizing a chosen welfare function. Since the final outcome heavily depends on the private information in possess of the players, a basic requirement in order to reach efficiency is the truthful revelation of this information. We show that for the kidney exchange problem, a class of (in principle) efficient mechanisms does not enjoy the incentive compatibility property and therefore is subject to possible manipulations made by the players in order to profit of the misrepresentation of their private information.

  18. Sexual Harassment: A problem unresolved!

    Directory of Open Access Journals (Sweden)

    N Vanishree

    2013-01-01

    Full Text Available Sexual harassment is a highly prevalent form of gender-based discrimination and sexual exploitation in the workplace and academic environment. In the dental field, there are a few studies regarding sexual harassment among the patients, professors and claims of their students. There is a silence of consent surrounding sexual harassment. It is clearly an issue about which the practicing dentists need to be informed in order to provide knowledgeable assessment and treatment for all patients. Dentists also have a role in advocacy, expert consultation or testimony, research and prevention through education and training. It is a fact that sexual harassment is very commonly encountered by almost everyone especially women. It is the most unresolved and under recognized problem of today especially when professionals are concerned. Preventing sexual harassment requires a considerable investment of time and personnel. This paper reviews the topic of sexual harassment as a problem from its legal aspects and recommendations for further steps to resolve this issue in dentistry.

  19. On materials problems in INTOR

    International Nuclear Information System (INIS)

    Schiller, P.

    1981-01-01

    In INTOR, an attempt has been made to define more precisely the performance limits of important parts of the device. For the first wall, it appears that under the assumed conditions, the erosion by the plasma will be the most important problem. Part of this problem may disappear with the advancement of plasma physics, but other erosion mechanisms will remain and therefore limit the lifetime of this component and influence heavily the burning of the plasma. The breeding blanket requires particular attention in order to achieve a reasonable breeding factor and to maintain at a low level the tritium inventory. The necessity to keep the tritium inventory down can be met better by temperatures which are high enough to allow an easy outgasing of the tritium from the breeder material. This temperature may bring the canning material in a range where swelling is important and lifetime limiting. Radiation damage in the superconducting coils will be low since otherwise the radiation heating would be difficult to be eliminated by the liquid helium, but the damage may be high enough to put seriously in question the integrity of the insulating material, especially under cyclic conditions. The INTOR exercise may be considered an excellent way to show up where to-days materials have their limits in a fusion reactor. It leads inevitably to the conclusion that, for the construction of economic power reactors, it will be necessary to start immediately an alloy development programme. (orig./GG)

  20. Common Sleep Problems (For Teens)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Common Sleep Problems KidsHealth / For Teens / Common Sleep Problems What's ... have emotional problems, like depression. What Happens During Sleep? You don't notice it, of course, but ...

  1. How to solve mathematical problems

    CERN Document Server

    Wickelgren, Wayne A

    1995-01-01

    Seven problem-solving techniques include inference, classification of action sequences, subgoals, contradiction, working backward, relations between problems, and mathematical representation. Also, problems from mathematics, science, and engineering with complete solutions.

  2. No Problem? No Research, Little Learning ... Big Problem!

    Directory of Open Access Journals (Sweden)

    Fernando Ornelas Marques

    2012-06-01

    Full Text Available The motivation to carry out this study stemmed from the generalized perception that nowadays youth lacks the skills for the 21st century. Especially the high-level competences like critical thinking, problem solving and autonomy. Several tools can help to improve these competences (e.g. the SCRATCH programming language, but, as researchers and educators, we are mostly concerned with the skill to recognize problems. What if we do not find problems to solve? What if we do not even feel the need to find or solve problems? The problem is to recognize the problem; the next step is to equate the problem; finally we have to feel the need to solve it. No need? No invention. Recognizing a problem is probably the biggest problem of everyday life, because we are permanently faced with problems (many ill-defined problems, which we need to identify, equate and solve.

  3. Follistatin allows efficient retroviral-mediated gene transfer into rat liver

    International Nuclear Information System (INIS)

    Borgnon, Josephine; Djamouri, Fatima; Lorand, Isabelle; Rico, Virginie Di; Loux, Nathalie; Pages, Jean-Christophe; Franco, Dominique; Capron, Frederique; Weber, Anne

    2005-01-01

    Retroviral vectors are widely used tools for gene therapy. However, in vivo gene transfer is only effective in dividing cells, which, in liver, requires a regenerative stimulus. Follistatin is effective in promoting liver regeneration after 90% and 70% hepatectomy in rats. We studied its efficacy on liver regeneration and retroviral-mediated gene delivery in 50% hepatectomized rats. When human recombinant follistatin was infused into the portal vein immediately after 50% hepatectomy, hepatocyte proliferation was significantly higher than in control 50% hepatectomized rats. A single injection of virus particles administered 23 h after follistatin infusion resulted in more than 20% gene transduction efficiency in hepatocytes compared to 3% in control rats. It is concluded that a single injection of follistatin induces onset of proliferation in 50% hepatectomized rats and allows efficient retroviral-mediated gene transfer to the liver

  4. FBST for Cointegration Problems

    Science.gov (United States)

    Diniz, M.; Pereira, C. A. B.; Stern, J. M.

    2008-11-01

    In order to estimate causal relations, the time series econometrics has to be aware of spurious correlation, a problem first mentioned by Yule [21]. To solve the problem, one can work with differenced series or use multivariate models like VAR or VEC models. In this case, the analysed series are going to present a long run relation i.e. a cointegration relation. Even though the Bayesian literature about inference on VAR/VEC models is quite advanced, Bauwens et al. [2] highlight that "the topic of selecting the cointegrating rank has not yet given very useful and convincing results." This paper presents the Full Bayesian Significance Test applied to cointegration rank selection tests in multivariate (VAR/VEC) time series models and shows how to implement it using available in the literature and simulated data sets. A standard non-informative prior is assumed.

  5. RTD problems at Darlington

    International Nuclear Information System (INIS)

    McAllindon, D.; Sloan, D.; Mayer, P.

    1997-01-01

    Resistance Temperature Detectors (RTDs) and their measurement circuit components have been a significant maintenance item at Darlington. Analysis of the problems has shown that RTDs and electrical penetrations (EPs) have been the largest sources of faults. A failure mechanism in which the RTD electrical resistance shifts upward was identified as a major source of RTD failures, which prompted a detailed failure investigation by Ontario Hydro Technologies (OHT). The investigation concluded that the root cause failure mechanism is chlorine contamination of the platinum wire during manufacture which resulted in surface damage to the wire and flaking of the wire surface during operation. Electrical penetrations in Darlington are of a pre-built modular design with two crimps internal to the EP. Spurious resistance in poor quality crimps in the EPs lead to errors in resistance measurement. The problem led to a complex and costly job to insert new modules in existing spare EPs. (author)

  6. The generation problem

    International Nuclear Information System (INIS)

    Ecker, G.

    1983-01-01

    Evidence for the generation structure of quarks and leptons is reviewed. The two main aspects of the generation problem are emphasized. The concept and possible problems of horizontal symmetries are discussed. Two different mechanisms for horizontal symmetries are considered leading to a generalized permutation symmetry in SU(2)sub(L) x u(1) in one case. The second mechanism uses the discrete unbroken subgroup of an axial U(1) with hypercolour anomalies in composite models. A concrete realization in the rishon model is investigated. The two different approaches produce almost identical quark mass matrices for three generations. In addition to a correct prediction for the Cabibbo angle the models yield a very small Kobayashi-Maskawa mixing angle Theta 3 and thus provide for a natural explanation of the smallness of CP violation. (Author)

  7. Problems of judiciary trust

    Directory of Open Access Journals (Sweden)

    Vuković Slobodan

    2007-01-01

    Full Text Available Topic of the article is problem of trust in judiciary as a most important part of legal system. For all empirical researches so far have shown very law degree of this trust many authors were searching for the causes of this phenomenon. Among multifold causes some are special worth while to be mentioned here: historical inheritance, political pressures, delaying of judiciary decisions, respect of the laws, transferring of responsibility from political power to the judiciary, public comments of judiciary decisions, media pressures, efficiency of judiciary and police. Among inner factors author pays attention to competency of judges, modes of penal policy, modes of judges’ entitlement, problems of communication, involvement into criminal and corruptional affairs, etc.

  8. Energy - the existential problem

    International Nuclear Information System (INIS)

    Michaelis, H.

    1980-01-01

    The volume contains the 16 speeches held on the meeting of the German Atom Forum Nuclear energy with the background of the world's energy situation of January 1980. They deal with the new dimensions of the world energy problem, possibilities of an alternative long-term development, long-term prognoses, energy for the Third World, international problems of energy policy, availability of hard coal, energy policy in the Federal Republic, ways of application and substitution potential of nuclear energy, industrial development, new energy sources, the purpose of energy decentralized energy supply, the energy demand, environment protection as a vehicle for cultural criticism. The editor sees in the debate a serious approach between supporters and opponents of nuclear energy. (HSCH) [de

  9. Translating a wicked problem

    DEFF Research Database (Denmark)

    Tietjen, Anne; Jørgensen, Gertrud

    2016-01-01

    , place-based and project-oriented process directed at concrete physical outcomes. We frame strategic planning as a translation process where the interaction between human and non-human actors translates a unique, complex and contested situation into an innovated situation. We find that local physical...... on the case of a Danish planning process which was carried out in collaboration with a charitable trust, this paper discusses an emerging strategic planning approach at the municipal level. We use the concept of wicked problems, strategic planning theory and Actor-Network-Theory to study a collaborative...... projects played a major role in this process. First, they acted as a vehicle that assembled planners, politicians and stakeholders to work towards strategic visions across multiple scales. Second and consequently, they stimulated considerable second and third order effects in the form of shared problem...

  10. Problems in Cybersemiotic Modelling

    DEFF Research Database (Denmark)

    Brier, Søren

    2014-01-01

    the Peircean theory of the observer as the phaneroscopic foundation. 4. Cobley points out that both models, as they are combined in Cybersemiotics lacks to integrate a theory of interest and power. They are too consensual in their view on communication. This is a general problem in both theories. Still Luhmann...... do work with the power problem in his triple autopoietic communicative system theory as he sees communication specialized into generalized symbolic media, with no controlling center in the modern industrialized media society. Another way to go is Habermas’ critical theory in a social semiotic theory......Going from an empirical to an informational paradigm of cognition and communication, does not really help us to analyze, how the living systems manage to make a meaningful interpretation of environment that is useful for their survival and procreation. Other models are needed. 1. There is von...

  11. The grasshopper problem

    Science.gov (United States)

    Goulko, Olga; Kent, Adrian

    2017-11-01

    We introduce and physically motivate the following problem in geometric combinatorics, originally inspired by analysing Bell inequalities. A grasshopper lands at a random point on a planar lawn of area 1. It then jumps once, a fixed distance d, in a random direction. What shape should the lawn be to maximize the chance that the grasshopper remains on the lawn after jumping? We show that, perhaps surprisingly, a disc-shaped lawn is not optimal for any d>0. We investigate further by introducing a spin model whose ground state corresponds to the solution of a discrete version of the grasshopper problem. Simulated annealing and parallel tempering searches are consistent with the hypothesis that, for dcogs, where the integer n is close to π (arcsin⁡(√{π }d / 2 )) -1. We find transitions to other shapes for d ≳π-1 / 2.

  12. [Delayed reactions of active avoidance in white rats under conditions of an alternative choice].

    Science.gov (United States)

    Ioseliani, T K; Sikharulidze, N I; Kadagishvili, A Ia; Mitashvili, E G

    1995-01-01

    It was shown that if the rats had been learned and then tested using conventional pain punishment of erroneous choice they were able to solve the problem of alternative choice only in the period of immediate action of conditioned stimuli. If the pain punishment for erroneously chosen compartment had not been applied in animal learning and testing, rats successfully solved the problem of alternative choice even after 5-second delay. Introduction of pain punishment led to the frustration of earlier elaborated delayed avoidance reactions. Analysis of the obtained results allows us to argue that the apparent incapability of white rats for solving the problems of delayed avoidance is caused by simultaneous action of two different mechanisms, i.e., those of the active and passive avoidance rather than short-term memory deficit.

  13. Creativity and Problem Solving

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    2004-01-01

    This paper presents some modern and interdisciplinary concepts about creativity and creative processes of special relevance for Operational Research workers. Central publications in the area Creativity-Operational Research are shortly reviewed. Some creative tools and the Creative Problem Solving...... approach are also discussed. Finally, some applications of these concepts and tools are outlined. Some central references are presented for further study of themes related to creativity or creative tools....

  14. Problems of Chernobyl

    International Nuclear Information System (INIS)

    Shcherbyin, V.M.

    1998-01-01

    The collection comprises the materials of working meeting 'The Development of Technologies of the 'Ukrytie' Radioactive Waste Management', held on May 20-21, 1997 in Chernobyl. The results of research work of the experts of Ukraine and other countries directed on solving problems, concerning removal of fuel containing materials and other radioactive waste from destroyed Unit 4 of Chernobyl NPP are given. The data on waste quantities, their location and classification, strategy of waste management and some technologies are described

  15. The problem of plagiarism.

    Science.gov (United States)

    Cronin, Sherill Nones

    2007-01-01

    Unfortunately, the frequency of plagiarism is increasing in the nursing profession. We are encouraged to write, especially those of us in academia, and we all live very active lives. Pressure to publish, especially when coupled with lack of time, can lead to plagiarism, whether inadvertent or not. This article will discuss the problem of plagiarism and provide tips on how to avoid it in your own work.

  16. Creativity and problem Solving

    Directory of Open Access Journals (Sweden)

    René Victor Valqui Vidal

    2004-12-01

    Full Text Available This paper presents some modern and interdisciplinary concepts about creativity and creative processes of special relevance for Operational Research workers. Central publications in the area Creativity-Operational Research are shortly reviewed. Some creative tools and the Creative Problem Solving approach are also discussed. Finally, some applications of these concepts and tools are outlined. Some central references are presented for further study of themes related to creativity or creative tools.

  17. Government Is Whose Problem?

    OpenAIRE

    Jon D. Wisman

    2013-01-01

    This article addresses the political meaning of President Ronald Reagan's 1981 declaration that "government is the problem." Whereas historically the state had been used by elites to extract as much surplus as possible from producers, with democratization of the franchise, the state became the sole instrument that could limit, or even potentially end, the extraction of workers' surplus. Once control of the state is in principle democratized by the ballot box, the fortunes of the elite depend ...

  18. SOCIAL PROBLEMS AND ENVIRONMENT

    OpenAIRE

    Neeta Tiwari

    2017-01-01

    With ever increasing social and environmental problems, the principles of Socio-Economic Sustainable development have gained prime importance. Human activities and their after-effects, direct and indirect, strongly influence nature and its resources. Keeping the huge role played by mankind in sustaining the glory of nature in mind, development goals need to be shaped in accordance with the parallel development and benefit of nature. India, as a developing nation, has a landmark role to play i...

  19. Effect of Iron Containing Supplements on Rats' Dental Caries Progression

    OpenAIRE

    AR. Eshghi; R. Kowsari-Isfahan; M. Rezaiefar; M. Razavi; S. Zeighami

    2012-01-01

    Objective: Iron deficiency is the most common form of malnutrition in developing countries. Iron containing supplements have been used effectively to solve this problem. In children, because of teeth staining after taking iron drops, parents have the idea that iron drops are the cause of tooth decay; therefore, they limit this vital supplement in their children’s diet. Hereby, we evaluate the histologic effect of iron containing supplements on tooth caries in rice rats with cariogenic or non-...

  20. Tubuloglomerular feedback in Dahl rats

    DEFF Research Database (Denmark)

    Karlsen, F M; Leyssac, P P; Holstein-Rathlou, N H

    1998-01-01

    in both Dahl-S and salt-resistant Dahl rats on high- and low-salt diets. TGF was investigated in the closed-loop mode with a videometric technique, in which the response in late proximal flow rate to perturbations in Henle flow rate was measured. All Dahl rats showed a similar compensatory response...

  1. Neutron radiography of osteopetrotic rat

    International Nuclear Information System (INIS)

    Graf, B.; Renard, G.; Le Gall, J.; Laporte, A.

    1983-01-01

    The osteopetrotic disease is characterized by bone and cartilage tissue coexistence in the medullary space of long bones. The authors have studied ''congenital osteopetrosis'' of ''op'' rats. Comparing radiography, neutrography and histology, the evolution of the ''osteopetrotic disease'' and the healing of the ill rats by a single injection of bone marrow from normal animals is shown. (Auth.)

  2. The three-kidney rat

    International Nuclear Information System (INIS)

    Provoost, A.P.; Van Aken, M.

    1984-01-01

    In contrast to the numerous research into the adaption of renal function when nephons are lost, much less attention has been paid to the effects of an extra kidney. Through the availability of inbred rat strains, techniques to transplant rat kidneys, and methods to measure total and individual kidney function repeatedly in the same animal, it became possible to study the renal function in rats with three kidneys. Adult male rats of a highly inbred Wistar strain were used. Nine recipients of a third kidney (3-K) were compared with 5 sham operated control (2-K) rats. The total GFR, as measured by the plasma clearance of Cr-5l EDTA, was taken 1,3,6,9, and 15 weeks after operation. The contribution of each kidney to the total renal function was determined by a Tc-99m DTPA scan performed at weeks 10 and 16. After transplantation the total GFR of 3-K rats was, in general, not different from the value before transplantation or from that of 2-K rats. The lack of increase of the GFR of 3-K rats was not the result of a non-functioning graft

  3. Ear Problems in Swimmers

    Directory of Open Access Journals (Sweden)

    Mao-Che Wang

    2005-08-01

    Full Text Available Acute diffuse otitis externa (swimmer's ear, otomycosis, exostoses, traumatic eardrum perforation, middle ear infection, and barotraumas of the inner ear are common problems in swimmers and people engaged in aqua activities. The most common ear problem in swimmers is acute diffuse otitis externa, with Pseudomonas aeruginosa being the most common pathogen. The symptoms are itching, otalgia, otorrhea, and conductive hearing loss. The treatment includes frequent cleansing of the ear canal, pain control, oral or topical medications, acidification of the ear canal, and control of predisposing factors. Swimming in polluted waters and ear-canal cleaning with cotton-tip applicators should be avoided. Exostoses are usually seen in people who swim in cold water and present with symptoms of accumulated debris, otorrhea and conductive hearing loss. The treatment for exostoses is transmeatal surgical removal of the tumors. Traumatic eardrum perforations may occur during water skiing or scuba diving and present with symptoms of hearing loss, otalgia, otorrhea, tinnitus and vertigo. Tympanoplasty might be needed if the perforations do not heal spontaneously. Patients with chronic otitis media with active drainage should avoid swimming, while patients who have undergone mastoidectomy and who have no cavity problems may swim. For children with ventilation tubes, surface swimming is safe in a clean, chlorinated swimming pool. Sudden sensorineural hearing loss and some degree of vertigo may occur after diving because of rupture of the round or oval window membrane.

  4. The inhomogeneous Suslov problem

    Energy Technology Data Exchange (ETDEWEB)

    García-Naranjo, Luis C., E-mail: luis@mym.iimas.unam.mx [Departamento de Matemáticas y Mecánica, IIMAS-UNAM, Apdo Postal 20-726, Mexico City 01000 (Mexico); Maciejewski, Andrzej J., E-mail: andrzej.j.maciejewski@gmail.com [J. Kepler Institute of Astronomy, University of Zielona Góra, Licealna 9, 65-417 Zielona Góra (Poland); Marrero, Juan C., E-mail: jcmarrero@ull.edu.es [ULL-CSIC, Geometría Diferencial y Mecánica Geométrica, Departamento de Matemática Fundamental, Facultad de Matemáticas, Universidad de la Laguna, La Laguna, Tenerife, Canary Islands (Spain); Przybylska, Maria, E-mail: M.Przybylska@if.uz.zgora.pl [Institute of Physics, University of Zielona Góra, Licealna 9, 65-417 Zielona Góra (Poland)

    2014-06-27

    We consider the Suslov problem of nonholonomic rigid body motion with inhomogeneous constraints. We show that if the direction along which the Suslov constraint is enforced is perpendicular to a principal axis of inertia of the body, then the reduced equations are integrable and, in the generic case, possess a smooth invariant measure. Interestingly, in this generic case, the first integral that permits integration is transcendental and the density of the invariant measure depends on the angular velocities. We also study the Painlevé property of the solutions. - Highlights: • We consider the Suslov problem of nonholonomic rigid body motion with inhomogeneous constraints. • We study the problem in detail for a particular choice of the parameters that has a clear physical interpretation. • We show that the equations of motion possess an invariant measure whose density depends on the velocity variables. • We show that the reduced system is integrable due to the existence of a transcendental first integral. • We study the Painlevé property of the solutions.

  5. The Online Specialization Problem

    Directory of Open Access Journals (Sweden)

    Ed Hong

    2006-01-01

    Full Text Available We study the online specialization problem, where items arrive in an online fashion for processing by one of n different methods. Each method has two costs: a processing cost (paid once for each item processed, and a set-up cost (paid only once, on the method's first use. There are n possible types of items; an item's type determines the set of methods available to process it. Each method has a different degree of specialization. Highly specialized methods can process few item types while generic methods may process all item types. This is a generalization of ski-rental and closely related to the capital investment problem of Y. Azar, Y. Bartal, E. Feuerstein, A. Fiat, S. Leonardi, and A. Rosen. On capital investment. In Algorithmica, 25(1:22-36, 1999. We primarily study the case where method i+1 is always more specialized than method i and the set-up cost for a more specialized method is always higher than that of a less specialized method. We describe an algorithm with competitive ratio O(log(n, and also show an Ω(log(n lower bound on the competitive ratio for this problem; this shows our ratio is tight up to constant factors.

  6. [Language Competence and Behavioural Problems in Preschool].

    Science.gov (United States)

    Rißling, J K; Melzer, J; Menke, B; Petermann, F; Daseking, M

    2015-10-01

    Children with language disorders are at increased risk of developing behavioural and emotional problems. The analysis focused on the question whether behavioural problems differ depending on the type of language deficit. The present study examines the behaviour of preschool children with different language impairments. The results of N=540 children aged between 4;0 and 5;11 years were analyzed. Language impairments were classified into phonetics/phonology (n=44), vocabulary (n=44), grammar (n=58), pragmatics (n=26) and multiple language impairments (n=171). In addition, a distinction was made between deficits in language production and comprehension. The children were compared with an unimpaired control group (n=197). The extent of emotional and behavioural problems were analyzed. The results indicate that emotional and behavioural problems differ depending on the type of language deficit already in preschoolers. Especially deficits in language comprehension, pragmatic impairments and multiple language impairments increase the risk of behavioural and emotional problems and hyperactivity. The relationship between language skills and emotional and behavioural problems should be emphasized in the developmental observation and documentation in preschool. In particular, the distinction between deficits in pragmatics and behavioural problems requires a differentiated examination to ensure an optimal intervention. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Postmarket Requirements and Commitments

    Data.gov (United States)

    U.S. Department of Health & Human Services — Provides information to the public on postmarket requirements and commitments. The phrase postmarket requirements and commitments refers to studies and clinical...

  8. Requirements for existing buildings

    DEFF Research Database (Denmark)

    Thomsen, Kirsten Engelund; Wittchen, Kim Bjarne

    This report collects energy performance requirements for existing buildings in European member states by June 2012.......This report collects energy performance requirements for existing buildings in European member states by June 2012....

  9. Replacing reserve requirements

    OpenAIRE

    Edward J. Stevens

    1993-01-01

    An examination of the fading significance of the Federal Reserve System's reserve requirements and the recent flowering of required clearing balances, a rapidly growing feature of Reserve Bank operations.

  10. Noticing relevant problem features: activating prior knowledge affects problem solving by guiding encoding

    Science.gov (United States)

    Crooks, Noelle M.; Alibali, Martha W.

    2013-01-01

    This study investigated whether activating elements of prior knowledge can influence how problem solvers encode and solve simple mathematical equivalence problems (e.g., 3 + 4 + 5 = 3 + __). Past work has shown that such problems are difficult for elementary school students (McNeil and Alibali, 2000). One possible reason is that children's experiences in math classes may encourage them to think about equations in ways that are ultimately detrimental. Specifically, children learn a set of patterns that are potentially problematic (McNeil and Alibali, 2005a): the perceptual pattern that all equations follow an “operations = answer” format, the conceptual pattern that the equal sign means “calculate the total”, and the procedural pattern that the correct way to solve an equation is to perform all of the given operations on all of the given numbers. Upon viewing an equivalence problem, knowledge of these patterns may be reactivated, leading to incorrect problem solving. We hypothesized that these patterns may negatively affect problem solving by influencing what people encode about a problem. To test this hypothesis in children would require strengthening their misconceptions, and this could be detrimental to their mathematical development. Therefore, we tested this hypothesis in undergraduate participants. Participants completed either control tasks or tasks that activated their knowledge of the three patterns, and were then asked to reconstruct and solve a set of equivalence problems. Participants in the knowledge activation condition encoded the problems less well than control participants. They also made more errors in solving the problems, and their errors resembled the errors children make when solving equivalence problems. Moreover, encoding performance mediated the effect of knowledge activation on equivalence problem solving. Thus, one way in which experience may affect equivalence problem solving is by influencing what students encode about the

  11. Improved apparatus for neutron capture therapy of rat brain tumors

    International Nuclear Information System (INIS)

    Liu, Hungyuan B.; Joel, D.D.; Slatkin, D.N.; Coderre, J.A.

    1994-01-01

    The assembly for irradiating tumors in the rat brain at the thermal neutron beam port of the Brookhaven Medical Research Reactor was redesigned to lower the average whole-body dose from different components of concomitant radiation without changing the thermal neutron fluence at the brain tumor. At present, the tumor-bearing rat is positioned in a rat holder that functions as a whole-body radiation shield. A 2.54 cm-thick collimator with a centered conical aperture, 6 cm diameter tapering to 2 cm diameter, is used to restrict the size of the thermal neutron field. Using the present holder and collimator as a baseline design, Monte Carlo calculations and mixed-field dosimetry were used to assess new designs. The computations indicate that a 0.5 cm-thick plate, made of 6 Li 2 CO 3 dispersed in polyethylene (Li-poly), instead of the existing rat holder, will reduce the whole-body radiation dose. Other computations show that a 10.16 cm-thick (4 inches) Li-poly collimator, having a centered conical aperture of 12 cm diameter tapering to 2 cm diameter, would further reduce the whole-body dose. The proposed irradiation apparatus of tumors in the rat brain, although requiring a 2.3-fold longer irradiation time, would reduce the average whole-body dose to less than half of that from the existing irradiation assembly. 7 refs., 4 figs., 7 tabs

  12. Both hypothyroidism and hyperthyroidism increase atrial fibrillation inducibility in rats.

    Science.gov (United States)

    Zhang, Youhua; Dedkov, Eduard I; Teplitsky, Diana; Weltman, Nathan Y; Pol, Christine J; Rajagopalan, Viswanathan; Lee, Bianca; Gerdes, A Martin

    2013-10-01

    Evidence indicates that cardiac hypothyroidism may contribute to heart failure progression. It is also known that heart failure is associated with an increased risk of atrial fibrillation (AF). Although it is established that hyperthyroidism increases AF incidence, the effect of hypothyroidism on AF is unclear. This study investigated the effects of different thyroid hormone levels, ranging from hypothyroidism to hyperthyroidism on AF inducibility in thyroidectomized rats. Thyroidectomized rats with serum-confirmed hypothyroidism 1 month after surgery were randomized into hypothyroid (N=9), euthyroid (N=9), and hyperthyroid (N=9) groups. Rats received placebo, 3.3-mg l-thyroxine (T4), or 20-mg T4 pellets (60-day release form) for 2 months, respectively. At the end of treatment, hypothyroid, euthyroid, and hyperthyroid status was confirmed. Hypothyroid animals showed cardiac atrophy and reduced cardiac systolic and diastolic functions, whereas hyperthyroid rats exhibited cardiac hypertrophy and increased cardiac function. Hypothyroidism and hyperthyroidism produced opposite electrophysiological changes in heart rates and atrial effective refractory period, but both significantly increased AF susceptibility. AF incidence was 78% in hypothyroid, 67% in hyperthyroid, and the duration of induced AF was also longer, compared with 11% in the euthyroid group (all Phyperthyroidism lead to increased AF vulnerability in a rat thyroidectomy model. Our results stress that normal thyroid hormone levels are required to maintain normal cardiac electrophysiology and to prevent cardiac arrhythmias and AF.

  13. Both Hypothyroidism and Hyperthyroidism Increase Atrial Fibrillation Inducibility in Rats

    Science.gov (United States)

    Zhang, Youhua; Dedkov, Eduard I.; Teplitsky, Diana; Weltman, Nathan Y.; Pol, Christine J.; Rajagopalan, Viswanathan; Lee, Bianca; Gerdes, A. Martin

    2014-01-01

    Background Evidence indicates that cardiac hypothyroidism may contribute to heart failure (HF) progression. It is also known that HF is associated with an increased risk of atrial fibrillation (AF). While it is established that hyperthyroidism increases AF incidence, the effect of hypothyroidism on AF is unclear. This study investigated the effects of different thyroid hormone levels, ranging from hypothyroidism to hyperthyroidism on AF inducibility in thyroidectomized rats. Methods and Results Thyroidectomized rats with serum confirmed hypothyroidism 1 month after surgery were randomized into hypothyroid (n=9), euthyroid (n=9) and hyperthyroid (n=9) groups. Rats received placebo, 3.3mg L-thyroxine (T4), or 20 mg T4 pellets (60 day release form) for 2 months, respectively. At the end of treatment, hypothyroid, euthyroid and hyperthyroid status was confirmed. Hypothyroid animals showed cardiac atrophy and reduced cardiac systolic and diastolic function, while hyperthyroid rats exhibited cardiac hypertrophy and increased cardiac function. Hypothyroidism and hyperthyroidism produced opposite electrophysiological changes in heart rates and atrial effective refractory period, but both significantly increased AF susceptibility. AF incidence was 78% in hypothyroid, 67% in hyperthyroid, and the duration of induced AF was also longer, compared with 11% in the euthyroid group (all phyperthyroidism lead to increased AF vulnerability in a rat thyroidectomy model. Our results stress that normal thyroid hormone levels are required to maintain normal cardiac electrophysiology and prevent cardiac arrhythmias and AF. PMID:24036190

  14. PIT Coating Requirements Analysis

    International Nuclear Information System (INIS)

    MINTEER, D.J.

    2000-01-01

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products

  15. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  16. Future Home Network Requirements

    DEFF Research Database (Denmark)

    Charbonnier, Benoit; Wessing, Henrik; Lannoo, Bart

    This paper presents the requirements for future Home Area Networks (HAN). Firstly, we discuss the applications and services as well as their requirements. Then, usage scenarios are devised to establish a first specification for the HAN. The main requirements are an increased bandwidth (towards 1...

  17. User Requirements for Wireless

    DEFF Research Database (Denmark)

    in the elicitation process. Cases and user requirement elements discussed in the book include: User requirements elicitation processes for children, construction workers, and farmers User requirements for personalized services of a broadcast company Variations in user involvement Practical elements of user...

  18. A further problem of the hard problem of consciousness | Gbenga ...

    African Journals Online (AJOL)

    Justifying this assertion is identified as the further problem of the hard problem of consciousness. This shows that assertions about phenomenal properties of mental experiences are wholly epistemological. Hence, the problem of explaining phenomenal properties of a mental state is not a metaphysical problem, and what is ...

  19. East Carnduff Unit: corrosion problems

    Energy Technology Data Exchange (ETDEWEB)

    Banks, C D

    1966-07-01

    Waterflooding of the East Carnduff Unit began in late 1962. The first injection line leak was discovered April 29, 1965. The first 6 leaks in the East Carnduff Unit occurred within a period of less than one month--a very startling and serious warning of pending problems. Analysis of the pipe removed showed a deep pit covered by a severe scale in the piping fitting. Several remedial actions were tried in order to develop the present inhibition program. First, the lines were cleaned as well as possible utilizing rubber pig spheres with normal injection pressure. This proved very effective and 2 passes wiped out most of the scale in the lines. Only one line required acid. After the lines had been cleaned, a water treating rate of an organic amine corrosion inhibitor, 10 ppm of the scale inhibitor, and bactericide at the rate of 40 ppm slugs 2 days per month was initiated. The above treating program is in use at the present time and is maintaining a very low leak frequency. This experience has demonstrated 2 important points in waterflood operations: (1) a bare piping system in warm brine service requires constant attention to insure that it is being kept clean; and (2) reliance cannot be placed on any one method of checking corrosion rates.

  20. THE EQUALITY PRINCIPLE REQUIREMENTS

    Directory of Open Access Journals (Sweden)

    CLAUDIA ANDRIŢOI

    2013-05-01

    Full Text Available The problem premises and the objectives followed: the idea of inserting the equality principle between the freedom and the justice principles is manifested in positive law in two stages, as a general idea of all judicial norms and as requirement of the owner of a subjective right of the applicants of an objective law. Equality in face of the law and of public authorities can not involve the idea of standardization, of uniformity, of enlisting of all citizens under the mark of the same judicial regime, regardless of their natural or socio-professional situation. Through the Beijing Platform and the position documents of the European Commission we have defined the integrative approach of equality as representing an active and visible integration of the gender perspective in all sectors and at all levels. The research methods used are: the conceptualist method, the logical method and the intuitive method necessary as means of reasoning in order to argue our demonstration. We have to underline the fact that the system analysis of the research methods of the judicial phenomenon doesn’t agree with “value ranking”, because one value cannot be generalized in rapport to another. At the same time, we must fight against a methodological extremism. The final purpose of this study is represented by the reaching of the perfecting/excellence stage by all individuals through the promotion of equality and freedom. This supposes the fact that the existence of a non-discrimination favourable frame (fairness represents a means and a condition of self-determination, and the state of perfection/excellency is a result of this self-determination, the condition necessary for the obtaining of this nondiscrimination frame for all of us and in conditions of freedom for all individuals, represents the same condition that promotes the state of perfection/excellency. In conclusion we may state the fact that the equality principle represents a true catalyst of the

  1. Do rats have orgasms?

    Science.gov (United States)

    Pfaus, James G.; Scardochio, Tina; Parada, Mayte; Gerson, Christine; Quintana, Gonzalo R.; Coria-Avila, Genaro A.

    2016-01-01

    Background Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs) in other species: 1) physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2) short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3) long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results Both male and female rats display behavioral patterns consistent with OLRs. Conclusions The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research. PMID:27799081

  2. Do rats have orgasms?

    Directory of Open Access Journals (Sweden)

    James G. Pfaus

    2016-10-01

    Full Text Available Background: Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method: Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs in other species: 1 physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2 short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3 long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results: Both male and female rats display behavioral patterns consistent with OLRs. Conclusions: The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research.

  3. Obstacle problems in mathematical physics

    CERN Document Server

    Rodrigues, J-F

    1987-01-01

    The aim of this research monograph is to present a general account of the applicability of elliptic variational inequalities to the important class of free boundary problems of obstacle type from a unifying point of view of classical Mathematical Physics.The first part of the volume introduces some obstacle type problems which can be reduced to variational inequalities. Part II presents some of the main aspects of the theory of elliptic variational inequalities, from the abstract hilbertian framework to the smoothness of the variational solution, discussing in general the properties of the free boundary and including some results on the obstacle Plateau problem. The last part examines the application to free boundary problems, namely the lubrication-cavitation problem, the elastoplastic problem, the Signorini (or the boundary obstacle) problem, the dam problem, the continuous casting problem, the electrochemical machining problem and the problem of the flow with wake in a channel past a profile.

  4. The spatial distribution of errors made by rats in Hebb-Williams type mazes in relation to the spatial properties of the blind alleys

    NARCIS (Netherlands)

    Boer, S. de; Bohus, B.

    The various configurations in series of Hebb-Williams type of mazes, which are used to measure problem solving behaviour in rats, differ markedly in structure. The relationship between error behaviour and spatial maze structure in control rats tested in a number of pharmacological experiments is

  5. Comprehensive behavioural analysis of Long Evans and Sprague-Dawley rats reveals differential effects of housing conditions on tests relevant to neuropsychiatric disorders.

    Directory of Open Access Journals (Sweden)

    Karly M Turner

    Full Text Available Genetic (G and environmental (E manipulations are known to alter behavioural outcomes in rodents, however many animal models of neuropsychiatric disorders only use a restricted selection of strain and housing conditions. The aim of this study was to examine GxE interactions comparing two outbred rat strains, which were housed in either standard or enriched cages. The strains selected were the albino Sprague-Dawley rat, commonly used for animal models, and the other was the pigmented Long Evans rat, which is frequently used in cognitive studies. Rats were assessed using a comprehensive behavioural test battery and included well-established tests frequently employed to examine animal models of neuropsychiatric diseases, measuring aspects of anxiety, exploration, sensorimotor gating and cognition. Selective strain and housing effects were observed on a number of tests. These included increased locomotion and reduced pre-pulse inhibition in Long Evans rats compared to Sprague Dawley rats; and rats housed in enriched cages had reduced anxiety-like behaviour compared to standard housed rats. Long Evans rats required fewer sessions than Sprague Dawley rats to learn operant tasks, including a signal detection task and reversal learning. Furthermore, Long Evans rats housed in enriched cages acquired simple operant tasks faster than standard housed Long Evans rats. Cognitive phenotypes in animal models of neuropsychiatric disorders would benefit from using strain and housing conditions where there is greater potential for both enhancement and deficits in performance.

  6. TRANSPORTATION SYSTEM REQUIREMENTS DOCUMENT

    International Nuclear Information System (INIS)

    2004-01-01

    This document establishes the Transportation system requirements for the U.S. Department of Energy's (DOE's) Civilian Radioactive Waste Management System (CRWMS). These requirements are derived from the Civilian Radioactive Waste Management System Requirements Document (CRD). The Transportation System Requirements Document (TSRD) was developed in accordance with LP-3.1Q-OCRWM, Preparation, Review, and Approval of Office of National Transportation Level-2 Baseline Requirements. As illustrated in Figure 1, the TSRD forms a part of the DOE Office of Civilian Radioactive Waste Management (OCRWM) Technical Baseline

  7. Direct Problems and Inverse Problems in Biometric Systems

    OpenAIRE

    Mihailescu Marius Iulian

    2013-01-01

    The article purpose is to describe the two sides of biometrics technologies, direct problems and inverse problems. The advance that we face today in field of Information Technology makes Information Security an inseparable part. The authentication has a huge role when we deal about security. The problems that can appear in implementing and developing biometrics systems is raising many problems, and one of the goal of this article is to focus on direct and inverse problems which is a new and c...

  8. Whose Problem Is Poverty?

    Science.gov (United States)

    Rothstein, Richard

    2008-01-01

    Closing or substantially narrowing achievement gaps requires combining school improvement with reforms to narrow the vast socioeconomic inequalities in the United States. Recognizing the effects of socioeconomic disparities on student learning is not "making excuses" for poor instruction or "letting schools off the hook" for raising student…

  9. Tackling a Problem School.

    Science.gov (United States)

    Lowe, Robert B.; Gervais, Robert L.

    1984-01-01

    Case study of a new principal who turns around an elementary school with a misbehaving student body and and apathetic staff by setting, publicizing, and consistently enforcing clear rules; documenting infractions; involving parents; encouraging student responsibility; and requiring lesson plans. (DCS)

  10. Tool Storage Problem Solved!

    Science.gov (United States)

    Klenke, Andrew M.; Dell, Tim W.

    2007-01-01

    Graduates of the automotive technology program at Pittsburg State University (PSU) generally enter the workforce in some type of automotive management role. As a result, the program does not require students to purchase their own tools, and it does not have room for all 280 majors to roll around a personal tool chest. Each instructor must maintain…

  11. Context-driven Salt Seeking Test (Rats)

    Science.gov (United States)

    Chang, Stephen E.; Smith, Kyle S.

    2018-01-01

    Changes in reward seeking behavior often occur through incremental learning based on the difference between what is expected and what actually happens. Behavioral flexibility of this sort requires experience with rewards as better or worse than expected. However, there are some instances in which behavior can change through non-incremental learning, which requires no further experience with an outcome. Such an example of non-incremental learning is the salt appetite phenomenon. In this case, animals such as rats will immediately seek out a highly-concentrated salt solution that was previously undesired when they are put in a novel state of sodium deprivation. Importantly, this adaptive salt-seeking behavior occurs despite the fact that the rats never tasted salt in the depleted state, and therefore never tasted it as a highly desirable reward. The following protocol is a method to investigate the neural circuitry mediating adaptive salt seeking using a conditioned place preference (CPP) procedure. The procedure is designed to provide an opportunity to discover possible dissociations between the neural circuitry mediating salt seeking and salt consumption to replenish the bodily deficit after sodium depletion. Additionally, this procedure is amenable to incorporating a number of neurobiological techniques for studying the brain basis of this behavior.

  12. The world food problem

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R A

    1974-07-01

    Argument continues in the world press as to the urgency of the food problem. Some economists in equating world food production statistics with population figures have convinced themselves there is more than enough food per capita and, accordingly, no problem. Looking in greater depth than these gross averages, however, we find that there is indeed a prospective problem, and of such a nature and magnitude as to tax all of mankind's talents and resources in its resolution. It is true that certain of the developed countries of the world in the last generation acquired agricultural production capabilities that notably exceeded the resident population's capacity to consume. 'Surplus' in these areas became an ugly word during this period of a generally favorable weather cycle, and restrictions on the amount of and that could be devoted to graincrops were imposed to curb this tremendous capacity. A fickle Mother Nature, however, has turned things around during the early 1970's by one or another of her many vacillations in the form of local drought, excess moisture, shortened growing season, or other means, in some of the major producing areas. Inconsequence, the food grain surpluses are now gone and the world is looking at a three to four week reserve at any given moment. The cost of food products available from exporting countries has doubled and trebled in price during the past two years. The potential for famine exceeds in magnitude anything the world has ever known. It is against this background that the World Food Conference will be held in Rome during November of this year. (author)

  13. The world food problem

    International Nuclear Information System (INIS)

    Olson, R.A.

    1974-01-01

    Argument continues in the world press as to the urgency of the food problem. Some economists in equating world food production statistics with population figures have convinced themselves there is more than enough food per capita and, accordingly, no problem. Looking in greater depth than these gross averages, however, we find that there is indeed a prospective problem, and of such a nature and magnitude as to tax all of mankind's talents and resources in its resolution. It is true that certain of the developed countries of the world in the last generation acquired agricultural production capabilities that notably exceeded the resident population's capacity to consume. 'Surplus' in these areas became an ugly word during this period of a generally favorable weather cycle, and restrictions on the amount of and that could be devoted to graincrops were imposed to curb this tremendous capacity. A fickle Mother Nature, however, has turned things around during the early 1970's by one or another of her many vacillations in the form of local drought, excess moisture, shortened growing season, or other means, in some of the major producing areas. Inconsequence, the food grain surpluses are now gone and the world is looking at a three to four week reserve at any given moment. The cost of food products available from exporting countries has doubled and trebled in price during the past two years. The potential for famine exceeds in magnitude anything the world has ever known. It is against this background that the World Food Conference will be held in Rome during November of this year. (author)

  14. Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

    International Nuclear Information System (INIS)

    Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

    1987-01-01

    Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance. (author)

  15. Invasive rats strengthen predation pressure on bird eggs in a South Pacific island rainforest.

    Science.gov (United States)

    Duron, Quiterie; Bourguet, Edouard; De Meringo, Hélène; Millon, Alexandre; Vidal, Eric

    2017-12-01

    Invasive rats ( Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects are undertaken on islands worldwide. However, such projects represent a huge investment and the decision-making process requires proper assessment of rat impacts. Here, we assessed the influence of two sympatric invasive rats ( Rattus rattus and R. exulans ) on native bird eggs in a New Caledonian rainforest, using artificial bird-nest monitoring. A total of 178 artificial nests containing two eggs of three different sizes were placed either on the ground or 1.5 m high and monitored at the start of the birds' breeding season. Overall, 12.4% of the nests were depredated during the first 7 days. At site 1, where nests were monitored during 16 days, 41.8% of the nests were depredated. The main predator was the native crow Corvus moneduloides , responsible for 62.9% of the overall predation events. Rats were responsible for only 22.9% of the events, and ate only small and medium eggs at both heights. Our experiment suggests that in New Caledonia, predation pressure by rats strengthens overall bird-nest predation, adding to that by native predators. Experimental rat control operations may allow reduced predation pressure on nests as well as the recording of biodiversity responses after rat population reduction.

  16. Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

    Energy Technology Data Exchange (ETDEWEB)

    Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

    1987-04-01

    Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.

  17. Transportation System Requirements Document

    International Nuclear Information System (INIS)

    1993-09-01

    This Transportation System Requirements Document (Trans-SRD) describes the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of this document is to define the system-level requirements for Transportation consistent with the CRWMS Requirement Document (CRD). These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presents an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. The interface identification and description are published in the CRWMS Interface Specification

  18. Appreciative Problem Solving

    DEFF Research Database (Denmark)

    Hansen, David

    2012-01-01

    Many industrial production work systems have increased in complexity, and their new business model scompete on innovation, rather than low cost.At a medical device production facility committed to Lean Production, a research project was carried out to use Appreciative Inquiry to better engage...... employee strengths in continuou simprovements of the work system. The research question was: “How can Lean problem solving and Appreciative Inquiry be combined for optimized work system innovation?” The research project was carried out as a co-creation process with close cooperation between researcher...

  19. Radiological waste problems

    International Nuclear Information System (INIS)

    Milanov, M.

    1990-01-01

    The chapter offers a description of the system of radioactive waste treatment as presented in the Belene NPP technical project and goes beyond the scope of the project evaluation in the account of the radioactive waste treatment, storage and disposal of other sources including the industry, science and the medicine of Bulgaria. The necessity for a developed legislative basis and an accepted policy regarding the radioactive waste management in the country is stressed upon. There is an elaboration on the problem of the construction of a new radioactive waste depository, the capacities of the existing disposal site being used up. 17 refs., 7 tabs. (R.Ts.)

  20. The nanostructure problem

    International Nuclear Information System (INIS)

    Billinge, S.

    2010-01-01

    Diffraction techniques are making progress in tackling the difficult problem of solving the structures of nanoparticles and nanoscale materials. The great gift of x-ray crystallography has made us almost complacent in our ability to locate the three-dimensional coordinates of atoms in a crystal with a precision of around 10 -4 nm. However, the powerful methods of crystallography break down for structures in which order only extends over a few nanometers. In fact, as we near the one hundred year mark since the birth of crystallography, we face a resilient frontier in condensed matter physics: our inability to routinely and robustly determine the structure of complex nanostructured and amorphous materials. Knowing the structure and arrangement of atoms in a solid is so fundamental to understanding its properties that the topic routinely occupies the early chapters of every solid-state physics textbook. Yet what has become clear with the emergence of nanotechnology is that diffraction data alone may not be enough to uniquely solve the structure of nanomaterials. As part of a growing effort to incorporate the results of other techniques to constrain x-ray refinements - a method called 'complex modeling' which is a simple but elegant approach for combining information from spectroscopy with diffraction data to solve the structure of several amorphous and nanostructured materials. Crystallography just works, so we rarely question how and why this is so, yet understanding the physics of diffraction can be very helpful as we consider the nanostructure problem. The relationship between the electron density distribution in three dimensions (i.e., the crystal structure) and an x-ray diffraction pattern is well established: the measured intensity distribution in reciprocal space is the square of the Fourier transform of the autocorrelation function of the electron density distribution ρ(r). The fact that we get the autocorrelation function (rather than just the density