Fatigue crack propagation: Probabilistic models and experimental evidence

International Nuclear Information System (INIS)

Lucia, A.C.; Jovanovic, A.

1987-01-01

The central aim of the LWR Primary Circuit Component Life Prediction Project, going on at JRC-Ispra, is to develop and check a 'procedure' (encompassing monitoring and inspection, data collection and analysis, prediction) allowing the quantitatives estimation of the accumulation of structural damage and of the residual lifetime. The ongoing activity matches theoretical development and experimentation, the latter being at present essentially based on a test-rig for room-temperature fatigue cycling of 1:5 scaled models of pressure vessels. During Phase I of fatigue testing of vessel R2, different pieces of information coming from material characterization, non-destructive inspection, continuous monitoring, stress analysis, have been merged and used to infere the future behaviour of the structure. The prediction of residual lifetime (cycles to failure), based on the outcomes of the ultrasonic continuous monitoring and made by means of the COVASTOL code, was in quite good agreement with experimental evidence. (orig./HP)

How experimental biology and ecology can support evidence-based decision-making in conservation: avoiding pitfalls and enabling application.

Science.gov (United States)

Cooke, Steven J; Birnie-Gauvin, Kim; Lennox, Robert J; Taylor, Jessica J; Rytwinski, Trina; Rummer, Jodie L; Franklin, Craig E; Bennett, Joseph R; Haddaway, Neal R

2017-01-01

Policy development and management decisions should be based upon the best available evidence. In recent years, approaches to evidence synthesis, originating in the medical realm (such as systematic reviews), have been applied to conservation to promote evidence-based conservation and environmental management. Systematic reviews involve a critical appraisal of evidence, but studies that lack the necessary rigour (e.g. experimental, technical and analytical aspects) to justify their conclusions are typically excluded from systematic reviews or down-weighted in terms of their influence. One of the strengths of conservation physiology is the reliance on experimental approaches that help to more clearly establish cause-and-effect relationships. Indeed, experimental biology and ecology have much to offer in terms of building the evidence base that is needed to inform policy and management options related to pressing issues such as enacting endangered species recovery plans or evaluating the effectiveness of conservation interventions. Here, we identify a number of pitfalls that can prevent experimental findings from being relevant to conservation or would lead to their exclusion or down-weighting during critical appraisal in a systematic review. We conclude that conservation physiology is well positioned to support evidence-based conservation, provided that experimental designs are robust and that conservation physiologists understand the nuances associated with informing decision-making processes so that they can be more relevant.

CHANGING OF THE BIOCHEMICAL INDICES ON REGENERATION OF EXPERIMENTAL DEFECT OF THE MANDIBLE BONE

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A. Borysenko

2012-09-01

Full Text Available Summary. The results of an experimental biochemical investigation on the influence of the proposed drug composition for the experimental mandible bone defect regeneration in rats were presented. The high efficiency and osteoregenerative properties of this paste were shown. The experimental investigations showed that the proposed drug composition exerts a considerable normalization influence upon the biochemical indicators of bone mineral metabolism, comparable to Collapan influence.

Evaluating the use of key performance indicators to evidence the patient experience.

Science.gov (United States)

McCance, Tanya; Hastings, Jack; Dowler, Hilda

2015-11-01

To test eight person-centred key performance indicators and the feasibility of an appropriate measurement framework as an approach to evidencing the patient experience. The value of measuring the quality of patient care is undisputed in the international literature, however, the type of measures that can be used to generate data that is meaningful for practice continues to be debated. This paper offers a different perspective to the 'measurement' of the nursing and midwifery contribution to the patient experience. Fourth generation evaluation was the methodological approach used to evaluate the implementation of the key performance indicators and measurement framework across three participating organisations involving nine practice settings. Data were collected by repeated use of claims, concerns and issues with staff working across nine participating sites (n = 18) and the senior executives from the three partner organisations (n = 12). Data were collected during the facilitated sessions with stakeholders and analysed in conjunction with the data generated from the measurement framework. The data reveal the inherent value placed on the evidence generated from the implementation of the key performance indicators as reflected in the following themes: measuring what matters; evidencing the patient experience; engaging staff; a focus for improving practice; and articulating and demonstrating the positive contribution of nursing and midwifery. The implementation of the key performance indicators and the measurement framework has been effective in generating evidence that demonstrates the patient experience. The nature of the data generated not only privileges the patient voice but also offers feedback to nurses and midwives that can inform the development of person-centred cultures. The use of these indicators will produce evidence of patient experience that can be used by nurse and midwives to celebrate and further inform person-centred practice. © 2015 John

Evidence of low dimensional chaos in renal blood flow control in genetic and experimental hypertension

Science.gov (United States)

Yip, K.-P.; Marsh, D. J.; Holstein-Rathlou, N.-H.

1995-01-01

We applied a surrogate data technique to test for nonlinear structure in spontaneous fluctuations of hydrostatic pressure in renal tubules of hypertensive rats. Tubular pressure oscillates at 0.03-0.05 Hz in animals with normal blood pressure, but the fluctuations become irregular with chronic hypertension. Using time series from rats with hypertension we produced surrogate data sets to test whether they represent linearly correlated noise or ‘static’ nonlinear transforms of a linear stochastic process. The correlation dimension and the forecasting error were used as discriminating statistics to compare surrogate with experimental data. The results show that the original experimental time series can be distinguished from both linearly and static nonlinearly correlated noise, indicating that the nonlinear behavior is due to the intrinsic dynamics of the system. Together with other evidence this strongly suggests that a low dimensional chaotic attractor governs renal hemodynamics in hypertension. This appears to be the first demonstration of a transition to chaotic dynamics in an integrated physiological control system occurring in association with a pathological condition.

The process of construction of evidence: An analysis of the use of indicators in two decisions of innovation policy

Energy Technology Data Exchange (ETDEWEB)

Boavida, N.; Moniz, A.; Laranja, M.

2016-07-01

Despite increasing calls for evidence-based policies, knowledge about the practical use of evidences remains limited. This paper studies the process of construction of evidences in decisions of innovation policy to understand how evidences were used. It analysis the use of indicators and other evidences through interviews conducted to inquire about the two decisions: an electric mobility policy and a nanotechnology laboratory. Results show indicators and other evidences were brought to decision processes according to their availability and capacity to support the different interests of the actors and the stakeholders. Their role was influenced by the particular situation of the decision makers. More importantly, the use of persuasive analytical evidences appears to be related with the adversity of the policy context. In addition, research suggests that indicators are one tool among others to foster innovation decisions. In fact, the relatively minor instrumental role of indicators suggests that indicators are mostly a complementary instrument of decision. When used relevantly, indicators can offer support to a decision. But there are other significant influences that need to be taken into account to understand the specific role indicators and other evidences play, such as the social relations of the decision makers and their emotional-intuitive decisions. (Author)

Experimental evidence of a symbiosis between red-cockaded woodpeckers and fungi.

Science.gov (United States)

Jusino, Michelle A; Lindner, Daniel L; Banik, Mark T; Rose, Kevin R; Walters, Jeffrey R

2016-03-30

Primary cavity excavators, such as woodpeckers, are ecosystem engineers in many systems. Associations between cavity excavators and fungi have long been hypothesized to facilitate cavity excavation, but these relationships have not been experimentally verified. Fungi may help excavators by softening wood, while excavators may facilitate fungal dispersal. Here we demonstrate that excavators facilitate fungal dispersal and thus we report the first experimental evidence of a symbiosis between fungi and a cavity excavator, the red-cockaded woodpecker (RCW,Picoides borealis). Swab samples of birds showed that RCWs carry fungal communities similar to those found in their completed excavations. A 26-month field experiment using human-made aseptically drilled excavations in live trees, half of which were inaccessible to RCWs, demonstrated that RCWs directly alter fungal colonization and community composition. Experimental excavations that were accessible to RCWs contained fungal communities similar to natural RCW excavations, whereas inaccessible experimental excavations contained significantly different fungal communities. Our work demonstrates a complex symbiosis between cavity excavators and communities of fungi, with implications for forest ecology, wildlife management, and conservation. © 2016 The Author(s).

Effect of land use change on ecosystem function of dung beetles: experimental evidence from Wallacea Region in Sulawesi, Indonesia

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SHAHABUDDIN

2011-07-01

Full Text Available Shahabuddin (2011 Effect of land use change on ecosystem function of dung beetles: experimental evidence from Wallacea Region in Sulawesi, Indonesia. Biodiversitas 12: 177-181. The deforestation of tropical forests and their subsequent conversion to human-dominated land-use systems is one of the most significant causes of biodiversity loss. However clear understanding of the links between ecological functions and biodiversity is needed to evaluate and predict the true environmental consequences of human activities. This study provided experimental evidence comparing ecosystem function of dung beetles across a land use gradient ranging from natural tropical forest and agroforestry systems to open cultivated areas in Central Sulawesi. Therefore, standardized dung pats were exposed at each land-use type to assess dung removal and parasite suppression activity by dung beetles. The results showed that ecosystem function of dung beetles especially dung burial activity were remarkably disrupted by land use changes from natural forest to open agricultural area. Dung beetles presence enhanced about 53% of the total dung removed and reduced about 83% and 63% of fly population and species number respectively, indicating a pronounce contribution of dung beetles in our ecosystem.

Experimental evidence of body centered cubic iron in Earth's core

Science.gov (United States)

Hrubiak, R.; Meng, Y.; Shen, G.

2017-12-01

The Earth's core is mainly composed of iron. While seismic evidence has shown a liquid outer core and a solid inner core, the crystalline nature of the solid iron at the core condition remains debated, largely due to the difficulties in experimental determination of exact polymorphs at corresponding pressure-temperature conditions. We have examined crystal structures of iron up to 220 GPa and 6000 K with x-ray diffraction using a double-sided laser heating system at HPCAT, Advanced Photon Source. The iron sample is confined in a small chamber surrounded by single crystal MgO. The laser power can be modulated together with temperature measurements. The modulated heating of iron in an MgO single crystal matrix allows for microstructure analysis during heating and after the sample is quenched. We present experimental evidence of a body-centered-cubic (BCC) iron from about 100 GPa and 3000 K to at least 220 GPa and 4000 K. The observed BCC phase may be consistent with a theoretically predicted BCC phase that is dynamically stable in similar pressure-temperature conditions [1]. We will discuss the stability region of the BCC phase and the melting curve of iron and their implications in the nature of the Earth's inner core. References: A. B. Belonoshko et al., Nat. Geosci., 1-6 (2017).

An experimental study on developing seismic damage indicator appearing OBE exceedance

International Nuclear Information System (INIS)

Park, D. S.; Kwon, K. J.; Lee, J. L.

2000-01-01

Immediate measurement should be taken depending on the level of seismic damage to nuclear power plants when an earthquake exceeds Operating Base Earthquake by NRC regulatory guide. An earthquake at nuclear plant site is felt with seismic instrument and analyzed by seismic monitoring systems. However, if operators of insufficient knowledge to earthquake can recognize the intensity of the earthquake with a subsidiary indicating model, more immediate response can be conducted. This subsidiary indicating model is called seismic damage indicator. In this regard, an experimental study using shaking table was conducted to develop the seismic damage indicator by CAV and OBE compatible with NRC standard response spectrum. In this test result, stacked acrylic cylinders were manufactured to behave consistently for each direction of seismic load. If the developed SDI is installed in nuclear power plants, it is seemed to be useful in easily determining OBE exceedance easily, and counteracting by plant operator along with the existing seismic monitoring systems

Quasi-experimental study designs series-paper 12: strengthening global capacity for evidence synthesis of quasi-experimental health systems research.

Science.gov (United States)

Rockers, Peter C; Tugwell, Peter; Grimshaw, Jeremy; Oliver, Sandy; Atun, Rifat; Røttingen, John-Arne; Fretheim, Atle; Ranson, M Kent; Daniels, Karen; Luiza, Vera Lucia; Bärnighausen, Till

2017-09-01

Evidence from quasi-experimental studies is often excluded from systematic reviews of health systems research despite the fact that such studies can provide strong causal evidence when well conducted. This article discusses global coordination of efforts to institutionalize the inclusion of causal evidence from quasi-experiments in systematic reviews of health systems research. In particular, we are concerned with identifying opportunities for strengthening capacity at the global and local level for implementing protocols necessary to ensure that reviews that include quasi-experiments are consistently of the highest quality. We first describe the current state of the global infrastructure that facilitates the production of systematic reviews of health systems research. We identify five important types of actors operating within this infrastructure: review authors; synthesis collaborations that facilitate the review process; synthesis interest groups that supplement the work of the larger collaborations; review funders; and end users, including policymakers. Then, we examine opportunities for intervening to build the capacity of each type of actors to support the inclusion of quasi-experiments in reviews. Finally, we suggest practical next steps for proceeding with capacity building efforts. Because of the complexity and relative nascence of the field, we recommend a carefully planned and executed approach to strengthening global capacity for the inclusion of quasi-experimental studies in systematic reviews. Copyright © 2017 Elsevier Inc. All rights reserved.

Experimental evidence for inherent Lévy search behaviour in foraging animals.

Science.gov (United States)

Kölzsch, Andrea; Alzate, Adriana; Bartumeus, Frederic; de Jager, Monique; Weerman, Ellen J; Hengeveld, Geerten M; Naguib, Marc; Nolet, Bart A; van de Koppel, Johan

2015-05-22

Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Lignin biodegradation: experimental evidence, molecular, biochemical and physiological mechanisms

Energy Technology Data Exchange (ETDEWEB)

Monties, B

1985-01-01

A critical review is presented of English, French and some German language literature, mainly from 1983 onwards. It examines experimental evidence on the behaviour as barriers to biodegradation of lignins and phenolic polymers such as tannins and suberins. The different molecular mechanisms of lignolysis by fungi (mainly), actinomycetes and bacteria are examined. A new biochemical approach to the physiological mechanism of regulation of lignolytic activities is suggested based on the discoveries of ligniolytic enzymes: effects of nitrogen, oxygen and substrate are discussed. It is concluded that a better knowledge of the structure and reactivity of phenolic barriers is needed in order to control the process of lignolysis.

The fetal programming of food preferences: current clinical and experimental evidence.

Science.gov (United States)

Dalle Molle, R; Bischoff, A R; Portella, A K; Silveira, P P

2015-09-28

Increased energy consumption is one of the major factors implicated in the epidemic of obesity. There is compelling evidence, both clinical and experimental, that fetal paucity of nutrients may have programming effects on feeding preferences and behaviors that can contribute to the development of diseases. Clinical studies in different age groups show that individuals born small for their gestational age (SGA) have preferences towards highly caloric foods such as carbohydrates and fats. Some studies have also shown altered eating behaviors in SGA children. Despite an apparent discrepancy in different age groups, all studies seem to converge to an increased intake of palatable foods in SGA individuals. Small nutrient imbalances across lifespan increase the risk of noncommunicable diseases in adult life. Homeostatic factors such as altered responses to leptin and insulin and alterations in neuropeptides associated with appetite and satiety are likely involved. Imbalances between homeostatic and hedonic signaling are another proposed mechanism, with the mesocorticolimbic dopaminergic pathway having differential reward and pleasure responses when facing palatable foods. Early exposure to undernutrition also programs hypothalamic-pituitary-adrenal axis, with SGA having higher levels of cortisol in different ages, leading to chronic hyperactivity of this neuroendocrine axis. This review summarizes the clinical and experimental evidence related to fetal programming of feeding preferences by SGA.

Magnetic order in graphite: Experimental evidence, intrinsic and extrinsic difficulties

International Nuclear Information System (INIS)

Esquinazi, P.; Barzola-Quiquia, J.; Spemann, D.; Rothermel, M.; Ohldag, H.; Garcia, N.; Setzer, A.; Butz, T.

2010-01-01

We discuss recently obtained data using different experimental methods including magnetoresistance measurements that indicate the existence of metal-free high-temperature magnetic order in graphite. Intrinsic as well as extrinsic difficulties to trigger magnetic order by irradiation of graphite are discussed in view of recently published theoretical work.

Further evidence for periodontal disease as a risk indicator for adverse pregnancy outcomes.

Science.gov (United States)

Turton, Mervyn; Africa, Charlene W J

2017-06-01

Although there is increasing evidence to suggest an association between periodontal disease and adverse pregnancy outcomes, the issue remains controversial. This study tested the hypothesis that periodontal disease is a risk indicator for preterm delivery of low-birthweight infants. The study sample comprised 443 pregnant women with a mean (± standard deviation) age of 24.13 (±5.30) years. At first visit, maternal oral health status was assessed by the measurement of probing pocket depth and clinical attachment loss, and periodontal status was graded as absent, mild, moderate or severe. An association was sought between pregnancy outcomes and maternal periodontal status. While controlling for other factors, significant associations were found between pregnancy outcomes and maternal periodontal index scores. This study provides further evidence that periodontal disease is a risk indicator for adverse pregnancy outcomes. © 2016 FDI World Dental Federation.

Facial expressions and speech acts: experimental evidences on the role of the upper face as an illocutionary force indicating device in language comprehension.

Science.gov (United States)

Domaneschi, Filippo; Passarelli, Marcello; Chiorri, Carlo

2017-08-01

Language scientists have broadly addressed the problem of explaining how language users recognize the kind of speech act performed by a speaker uttering a sentence in a particular context. They have done so by investigating the role played by the illocutionary force indicating devices (IFIDs), i.e., all linguistic elements that indicate the illocutionary force of an utterance. The present work takes a first step in the direction of an experimental investigation of non-verbal IFIDs because it investigates the role played by facial expressions and, in particular, of upper-face action units (AUs) in the comprehension of three basic types of illocutionary force: assertions, questions, and orders. The results from a pilot experiment on production and two comprehension experiments showed that (1) certain upper-face AUs seem to constitute non-verbal signals that contribute to the understanding of the illocutionary force of questions and orders; (2) assertions are not expected to be marked by any upper-face AU; (3) some upper-face AUs can be associated, with different degrees of compatibility, with both questions and orders.

A review of the evidence supporting the aesthetic orthodontic treatment need indices.

Science.gov (United States)

Borzabadi-Farahani, Ali

2012-11-01

Aesthetic improvement and psychological enhancement have been cited as justifications for orthodontic treatment. This paper reviews the evidence that relates malocclusion to psychological health and quality of life and explores whether this evidence supports the most commonly used aesthetic Orthodontic Treatment Need Indices (OTNI). The relevant cited material from the MEDLINE, Web of Science, Scopus, Cochrane databases, and scientific textbooks were used. The citation rate was confirmed by using the Google Scholar. The subjective nature of aesthetic indices and the variable perception of attractiveness between clinicians and patients, and among various cultures or countries are a few limitations of aesthetic OTNI. The available evidence of mainly cross-sectional studies on the link between malocclusion and either psychosocial well-being or quality of life is not conclusive, and sometimes contradictory, to suggest these characteristics are affected by malocclusions. Further, the long-term longitudinal studies did not suggest that people with malocclusion are disadvantaged psychologically, or their quality of life would be worse off, which challenges using aesthetic OTNI to assess the social and psychological implications of malocclusion. The subjective nature of aesthetic OTNI and the minor contributory role of malocclusion in psychosocial health or quality of life undermine using aesthetic indices to assess the likely social and psychological implications of malocclusion. Consequently, using aesthetic OTNI, as a method to quantify malocclusion remains open to debate. Various soft and hard-tissue analyses are used before formulating a treatment plan (i.e., assessment of sagittal and vertical skeletal relationships). The addition of a shortened version of these analyses to the aesthetic OTNI can be a good substitute for the aesthetic components of OTNI, if an assessment of the aesthetic aspects of malocclusion is intended. This reduces subjectivity and improves the

Experimental evidence for improved confinement with quasisymmetry in HSX

International Nuclear Information System (INIS)

Gerhardt, S.P.; Abdou, A.; Almagri, A.

2003-01-01

Plasmas produced by second harmonic electron cyclotron heating (ECH) in the HSX stellarator provide the first evidence of transport improvement due to quasisymmetry in a stellarator. Comparisons are made between plasmas in the base quasi helically symmetric (QHS) configuration and two neo classically degraded configurations which lack quasisymmetry (Mirror configurations). It is found that the plasma breakdown occurs more easily in the QHS configuration, indicating improved confinement of the breakdown electrons. The stored energy in the QHS configuration is up to six times larger than discharges in the Mirror configurations, and evidence is shown for enhanced prompt loss of trapped particles when the Mirror field is applied. The momentum damping rate is measured to be factors of three to four less in the QHS configuration than the Mirror configuration. (author)

Experimental identification of nitrogen-vacancy complexes in nitrogen implanted silicon

Science.gov (United States)

Adam, Lahir Shaik; Law, Mark E.; Szpala, Stanislaw; Simpson, P. J.; Lawther, Derek; Dokumaci, Omer; Hegde, Suri

2001-07-01

Nitrogen implantation is commonly used in multigate oxide thickness processing for mixed signal complementary metal-oxide-semiconductor and System on a Chip technologies. Current experiments and diffusion models indicate that upon annealing, implanted nitrogen diffuses towards the surface. The mechanism proposed for nitrogen diffusion is the formation of nitrogen-vacancy complexes in silicon, as indicated by ab initio studies by J. S. Nelson, P. A. Schultz, and A. F. Wright [Appl. Phys. Lett. 73, 247 (1998)]. However, to date, there does not exist any experimental evidence of nitrogen-vacancy formation in silicon. This letter provides experimental evidence through positron annihilation spectroscopy that nitrogen-vacancy complexes indeed form in nitrogen implanted silicon, and compares the experimental results to the ab initio studies, providing qualitative support for the same.

Evidence for side-chain π-delocalization in a planar substituted benzene: an experimental and theoretical charge density study on 2,5-dimethoxybenzaldehyde thiosemicarbazone.

Science.gov (United States)

Farrugia, Louis J; Khalaji, Aliakbar Dehno

2011-11-17

The charge density in 2,5-dimethoxybenzaldehyde thiosemicarbazone (1) has been studied experimentally using Mo-K(α) X-ray diffraction at 100 K, and by theory using DFT calculations at the B3LYP/6-311++G(2d,2p) level. The quantum theory of atoms in molecules (QTAIM) was used to investigate the extent of π-delocalization in the thioamide side-chain, which is virtually coplanar with the benzene ring. The experimental and theoretical ellipticity profiles along the bond paths were in excellent agreement, and showed that some of the formal single bonds in the side-chain have significant π-bond character. This view was supported by the magnitudes of the topological bond orders and by the delocalization indices δ(Ω(A), Ω(B)). An orbital decomposition of δ(Ω(A), Ω(B)) demonstrated that there was significant π-character in all the interchain non-H chemical bonds. On the other hand, the source function referenced at the interchain bond critical points could not provide any evidence for π-delocalization, showing instead only limited σ-delocalization between nearest neighbors. Overall, the topological evidence and the atomic graphs of the oxygen atoms did not provide convincing evidence for π-delocalization involving the methoxy substituents.

Latent interface-trap building in power VDMOSFETs: new experimental evidence and numerical simulation

International Nuclear Information System (INIS)

Ristic, G.F.; Jaksic, A.B.; Pejovic, M.M.

1999-01-01

The paper presents new experimental evidence of the latent interface-trap buildup during annealing of gamma-ray irradiated power VDMOSFETs. We try to reveal the nature of this still ill-understood phenomenon by isothermal annealing, switching temperature annealing and switching bias annealing experiments. The results of numerical simulation of interface-trap kinetics during annealing are also shown. (authors)

Linking clinical quality indicators to research evidence - a case study in asthma management for children.

Science.gov (United States)

Choong, Miew Keen; Tsafnat, Guy; Hibbert, Peter; Runciman, William B; Coiera, Enrico

2017-07-21

Clinical quality indicators are used to monitor the performance of healthcare services and should wherever possible be based on research evidence. Little is known however about the extent to which indicators in common use are based on research. The objective of this study is to measure the extent to which clinical quality indicators used in asthma management in children with outcome measurements can be linked to results in randomised controlled clinical trial (RCT) reports. This work is part of a broader research program to trial methods that improve the efficiency and accuracy of indicator development. National-level indicators for asthma management in children were extracted from the National Quality Measures Clearinghouse database and the National Institute for Health and Care Excellence quality standards by two independent appraisers. Outcome measures were extracted from all published English language RCT reports for asthma management in children below the age of 12 published between 2005 and 2014. The two sets were then linked by manually mapping both to a common set of Unified Medical Language System (UMLS) concepts. The analysis identified 39 indicators and 562 full text RCTs dealing with asthma management in children. About 95% (37/39) of the indicators could be linked to RCT outcome measures. It is possible to identify relevant RCT reports for the majority of indicators used to assess the quality of asthma management in childhood. The methods reported here could be automated to more generally support assessment of candidate indicators against the research evidence.

Transparency about past, present and future conduct : Experimental evidence on the impact of competitiveness

NARCIS (Netherlands)

Potters, J.J.M.; Hinloopen, J.; Normann, H-T

2009-01-01

Transparency relates to communication and information about the conduct of firms. Transparency can relate to the past, the present and the future and it can vary in format, content and reliability. In this chapter I review experimental evidence which relates to the impact of transparency on the

Experimental evidence of lateral flow in unsaturated homogeneous isotropic sloping soil due to rainfall

NARCIS (Netherlands)

Sinai, G.; Dirksen, C.

2006-01-01

This paper describes laboratory experimental evidence for lateral flow in the top layer of unsaturated sloping soil due to rainfall. Water was applied uniformly on horizontal and V-shaped surfaces of fine sand, at rates about 100 times smaller than the saturated hydraulic conductivity. Flow regimes

Infectivity of DWV associated to flower pollen: experimental evidence of a horizontal transmission route.

Directory of Open Access Journals (Sweden)

Maurizio Mazzei

Full Text Available Deformed wing virus (DWV is a honeybee pathogen whose presence is generally associated with infestation of the colony by the mite Varroa destructor, leading to the onset of infections responsible for the collapse of the bee colony. DWV contaminates bee products such as royal jelly, bee-bread and honey stored within the infected hive. Outside the hive, DWV has been found in pollen loads collected directly from infected as well as uninfected forager bees. It has been shown that the introduction of virus-contaminated pollen into a DWV-free hive results in the production of virus-contaminated food, whose role in the development of infected bees from virus-free eggs has been experimentally demonstrated. The aim of this study was twofold: (i to ascertain the presence of DWV on pollen collected directly from flowers visited by honeybees and then quantify the viral load and (ii determine whether the virus associated with pollen is infective. The results of our investigation provide evidence that DWV is present on pollen sampled directly from visited flowers and that, following injection in individuals belonging to the pollinator species Apis mellifera, it is able to establish an active infection, as indicated by the presence of replicating virus in the head of the injected bees. We also provide the first indication that the pollinator species Osmia cornuta is susceptible to DWV infection.

Expert opinions and scientific evidence for colonoscopy key performance indicators.

Science.gov (United States)

Rees, Colin J; Bevan, Roisin; Zimmermann-Fraedrich, Katharina; Rutter, Matthew D; Rex, Douglas; Dekker, Evelien; Ponchon, Thierry; Bretthauer, Michael; Regula, Jaroslaw; Saunders, Brian; Hassan, Cesare; Bourke, Michael J; Rösch, Thomas

2016-12-01

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Student Perceptions of Auditor Responses to Evidence of Suspicious Activities: An Experimental Assessment

Directory of Open Access Journals (Sweden)

David S Murphy

2015-12-01

Full Text Available This study assessed student perceptions of auditor responses to evidence that a client failed to respond appropriately to suspicious activities that could indicate money laundering. Subjects were presented with a series of randomized cases in which partner type (new vs. experienced, firm type (regional vs. international and audit fee materiality (not material, material to the local office only, material to the firm were manipulated asked to indicate their perceptions of the likelihood that an audit partner would discuss such evidence with the client, and the likelihood that the issue would be disclosed by the auditor. Both partner type and audit fee materiality was found to have significant effects on perceived likelihoods.

Laparoscopic surgery for benign and malign diseases of the digestive system: indications, limitations, and evidence.

Science.gov (United States)

Küper, Markus Alexander; Eisner, Friederike; Königsrainer, Alfred; Glatzle, Jörg

2014-05-07

The laparoscopic technique was introduced in gastrointestinal surgery in the mid 1980s. Since then, the development of this technique has been extraordinary. Triggered by technical innovations (stapling devices or coagulation/dissecting devices), nowadays any type of gastrointestinal resection has been successfully performed laparoscopically and can be performed laparoscopically dependent on the patient's condition. This summary gives an overview over 30 years of laparoscopic surgery with focus on today's indications and evidence. Main indications remain the more common procedures, e.g., appendectomy, cholecystectomy, bariatric procedures or colorectal resections. For all these indications, the laparoscopic approach has become the gold standard with less perioperative morbidity. Regarding oncological outcome there have been several high-quality randomized controlled trials which demonstrated equivalency between laparoscopic and open colorectal resections. Less common procedures like esophagectomy, oncological gastrectomy, liver and pancreatic resections can be performed successfully as well by an experienced surgeon. However, the evidence for these special indications is poor and a general recommendation cannot be given. In conclusion, laparoscopic surgery has revolutionized the field of gastrointestinal surgery by reducing perioperative morbidity without disregarding surgical principles especially in oncological surgery.

Theory and experimental evidence of phonon domains and their roles in pre-martensitic phenomena

Science.gov (United States)

Jin, Yongmei M.; Wang, Yu U.; Ren, Yang

2015-12-01

Pre-martensitic phenomena, also called martensite precursor effects, have been known for decades while yet remain outstanding issues. This paper addresses pre-martensitic phenomena from new theoretical and experimental perspectives. A statistical mechanics-based Grüneisen-type phonon theory is developed. On the basis of deformation-dependent incompletely softened low-energy phonons, the theory predicts a lattice instability and pre-martensitic transition into elastic-phonon domains via 'phonon spinodal decomposition.' The phase transition lifts phonon degeneracy in cubic crystal and has a nature of phonon pseudo-Jahn-Teller lattice instability. The theory and notion of phonon domains consistently explain the ubiquitous pre-martensitic anomalies as natural consequences of incomplete phonon softening. The phonon domains are characterised by broken dynamic symmetry of lattice vibrations and deform through internal phonon relaxation in response to stress (a particular case of Le Chatelier's principle), leading to previously unexplored new domain phenomenon. Experimental evidence of phonon domains is obtained by in situ three-dimensional phonon diffuse scattering and Bragg reflection using high-energy synchrotron X-ray single-crystal diffraction, which observes exotic domain phenomenon fundamentally different from usual ferroelastic domain switching phenomenon. In light of the theory and experimental evidence of phonon domains and their roles in pre-martensitic phenomena, currently existing alternative opinions on martensitic precursor phenomena are revisited.

Experimental Evidence for Wigner’s Tunneling Time

Science.gov (United States)

Camus, N.; Yakaboylu, E.; Fechner, L.; Klaiber, M.; Laux, M.; Mi, Y.; Hatsagortsyan, K. Z.; Pfeifer, T.; Keitel, C. H.; Moshammer, R.

2018-04-01

Tunneling of a particle through a barrier is one of the counter-intuitive properties of quantum mechanical motion. Thanks to advances in the generation of strong laser fields, new opportunities to dynamically investigate this process have been developed. In the so-called attoclock measurements the electron’s properties after tunneling are mapped on its emission direction. We investigate the tunneling dynamics and achieve a high sensitivity thanks to two refinements of the attoclock principle. Using near-IR wavelength we place firmly the ionization process in the tunneling regime. Furthermore, we compare the electron momentum distributions of two atomic species of slightly different atomic potentials (argon and krypton) being ionized under absolutely identical conditions. Experimentally, using a reaction microscope, we succeed in measuring the 3D electron momentum distributions for both targets simultaneously. Theoretically, the time resolved description of tunneling in strong-field ionization is studied using the leading quantum-mechanical Wigner treatment. A detailed analysis of the most probable photoelectron emission for Ar and Kr allows testing the theoretical models and a sensitive check of the electron initial conditions at the tunnel exit. The agreement between experiment and theory provides a clear evidence for a non-zero tunneling time delay and a non-vanishing longitudinal momentum at this point.

Study types and reliability of Real World Evidence compared with experimental evidence used in Polish reimbursement decision-making processes.

Science.gov (United States)

Wilk, N; Wierzbicka, N; Skrzekowska-Baran, I; Moćko, P; Tomassy, J; Kloc, K

2017-04-01

The aim of this study was to identify the relationship and impact between Real World Evidence (RWE) and experimental evidence (EE) in Polish decision-making processes for the drugs from selected Anatomical Therapeutic Chemical (ATC) groups. Descriptive study. A detailed analysis was performed for 58 processes from five ATC code groups in which RWE for effectiveness, or effectiveness and safety were cited in Agency for Health Technology Assessment and Tariff System's (AOTMiT) documents published between January 2012 and September 2015: Verification Analysis of AOTMiT, Statement of the Transparency Council of AOTMiT, and Recommendation of the President of AOTMiT. In 62% of the cases, RWE supported the EE and confirmed its main conclusions. The majority of studies in the EE group showed to be RCTs (97%), and the RWE group included mainly cohort studies (89%). There were more studies without a control group within RWE compared with the EE group (10% vs 1%). Our results showed that EE are more often assessed using Jadad, NICE or NOS scale by AOTMiT compared with RWE (93% vs 48%). When the best evidence within a given decision-making process is analysed, half of RWE and two-thirds of EE are considered high quality evidence. RWE plays an important role in the decision-making processes on public funding of drugs in Poland, contributing to nearly half (45%) of all the evidence considered. There exist such processes in which the proportion of RWE is dominant, with one process showing RWE as the only evidence presented. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Evolution and maintenance of sexual size dimorphism: Aligning phylogenetic and experimental evidence

Directory of Open Access Journals (Sweden)

Matjaz eKuntner

2014-06-01

Full Text Available Integrating the insights derived from both phylogenetic and experimental approaches offers a more complete understanding of evolutionary patterns and processes, yet it is rarely a feature of investigations of the evolutionary significance of trait variation. We combine these approaches to reinterpret the patterns and processes in the evolution of female biased sexual size dimorphism in Nephilidae, a spider lineage characterized by the most extreme sexual size dimorphism among terrestrial animals. We use a molecular phylogeny to reconstruct the size evolution for each sex and reveal a case of sexually dimorphic gigantism: both sexes steadily outgrow their ancestral sizes, but the female and male slopes differ, and hence sexual size dimorphism steadily increases. A review of the experimental evidence reveals a predominant net selection for large size in both sexes, consistent with the phylogenetic pattern for females but not for males. Thus, while sexual size dimorphism in spiders most likely originates and is maintained by fecundity selection on females, it is unclear what selection pressures prevent males from becoming as large as females. This integrated approach highlights the dangers of inferring evolutionary significance from experimental studies that isolate the effects of single selection pressures.

Experimental evidence against the paradigm of mortality risk aversion.

Science.gov (United States)

Rheinberger, Christoph M

2010-04-01

This article deals with the question of how societal impacts of fatal accidents can be integrated into the management of natural or man-made hazards. Today, many governmental agencies give additional weight to the number of potential fatalities in their risk assessments to reflect society's aversion to large accidents. Although mortality risk aversion has been proposed in numerous risk management guidelines, there has been no evidence that lay people want public decisionmakers to overweight infrequent accidents of large societal consequences against more frequent ones of smaller societal consequences. Furthermore, it is not known whether public decisionmakers actually do such overweighting when they decide upon the mitigation of natural or technical hazards. In this article, we report on two experimental tasks that required participants to evaluate negative prospects involving 1-100 potential fatalities. Our results show that neither lay people nor hazard experts exhibit risk-averse behavior in decisions on mortality risks.

Intraoperative radiotherapy in early stage breast cancer: potential indications and evidence to date

Science.gov (United States)

Kirby, A M

2015-01-01

Following early results of recent studies of intraoperative radiotherapy (IORT) in the adjuvant treatment of patients with early breast cancer, the clinical utility of IORT is a subject of much recent debate within the breast oncology community. This review describes the intraoperative techniques available, the potential indications and the evidence to date pertaining to local control and toxicity. We also discuss any implications for current practice and future research. PMID:25734489

Transanal total mesorectal excision: a systematic review of the experimental and clinical evidence.

Science.gov (United States)

Araujo, S E; Crawshaw, B; Mendes, C R; Delaney, C P

2015-02-01

Achieving a clear distal or circumferential resection margins with laparoscopic total mesorectal excision (TME) may be laborious, especially in obese males and when operating on advanced distal rectal tumors with a poor response to neoadjuvant treatment. Transanal (TaTME) is a new natural orifice translumenal endoscopic surgery modality in which the rectum is mobilized transanally using endoscopic techniques with or without laparoscopic assistance. We conducted a comprehensive systematic review of publications on this new technique in PubMed and Embase databases from January, 2008, to July, 2014. Experimental and clinical studies written in English were included. Experimental research with TaTME was done on pigs with and without survival models and on human cadavers. In these studies, laparoscopic or transgastric assistance was frequently used resulting in an easier upper rectal dissection and in a longer rectal specimen. To date, 150 patients in 16 clinical studies have undergone TaTME. In all but 15 cases, transabdominal assistance was used. A rigid transanal endoscopic operations/transanal endoscopic microsurgery (TEO/TEM) platform was used in 37 patients. Rectal adenocarcinoma was the indication in all except for nine cases of benign diseases. Operative times ranged from 90 to 460 min. TME quality was deemed intact, satisfactory, or complete. Involvement in circumferential resection margins was detected in 16 (11.8 %) patients. The mean lymph node harvest was equal or greater than 12 in all studies. Regarding morbidity, pneumoretroperitoneum, damage to the urethra, and air embolism were reported intraoperatively. Mean hospital stay varied from 4 to 14 days. Postoperative complications occurred in 34 (22.7 %) patients. TaTME with TEM is feasible in selected cases. Oncologic safety parameters seem to be adequate although the evidence relies on small retrospective series conducted by highly trained surgeons. Further studies are expected.

Experimental evidence of planar channeling in a periodically bent crystal

Energy Technology Data Exchange (ETDEWEB)

Bagli, E.; Bandiera, L.; Bellucci, V.; Camattari, R.; Germogli, G.; Guidi, V.; Mazzolari, A. [Univ. di Ferrara, Dipartimento di Fisica, Ferrara (Italy); INFN, Sezione di Ferrara (Italy); Berra, A.; Lietti, D.; Prest, M. [Univ. dell' Insubria, Como (Italy); INFN Sezione di Milano Bicocca, Milan (Italy); De Salvador, D. [INFN Laboratori Nazionali di Legnaro, Legnaro (Italy); Univ. di Padova, Dipartimento di Fisica, Padua (Italy); Lanzoni, L. [San Marino Univ. (San Marino). Dept. of Engineering; Tikhomirov, V.V. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Vallazza, E. [INFN, Sezione di Trieste (Italy)

2014-10-15

The usage of a crystalline undulator (CU) has been identified as a promising solution for generating powerful and monochromatic γ-rays. A CU was fabricated at Sensors and Semiconductors Lab (SSL) through the grooving method, i.e., by the manufacturing of a series of periodical grooves on the major surfaces of a crystal. The CU was extensively characterized both morphologically via optical interferometry at SSL and structurally via X-ray diffraction at ESRF. Then, it was finally tested for channeling with a 400 GeV/c proton beam at CERN. The experimental results were compared to Monte Carlo simulations. Evidence of planar channeling in the CU was firmly observed. Finally, the emission spectrum of the positron beam interacting with the CU was simulated for possible usage in currently existing facilities. (orig.)

Experimental and CFD evidence of multiple solutions in a naturally ventilated building.

Science.gov (United States)

Heiselberg, P; Li, Y; Andersen, A; Bjerre, M; Chen, Z

2004-02-01

This paper considers the existence of multiple solutions to natural ventilation of a simple one-zone building, driven by combined thermal and opposing wind forces. The present analysis is an extension of an earlier analytical study of natural ventilation in a fully mixed building, and includes the effect of thermal stratification. Both computational and experimental investigations were carried out in parallel with an analytical investigation. When flow is dominated by thermal buoyancy, it was found experimentally that there is thermal stratification. When the flow is wind-dominated, the room is fully mixed. Results from all three methods have shown that the hysteresis phenomena exist. Under certain conditions, two different stable steady-state solutions are found to exist by all three methods for the same set of parameters. As shown by both the computational fluid dynamics (CFD) and experimental results, one of the solutions can shift to another when there is a sufficient perturbation. These results have probably provided the strongest evidence so far for the conclusion that multiple states exist in natural ventilation of simple buildings. Different initial conditions in the CFD simulations led to different solutions, suggesting that caution must be taken when adopting the commonly used 'zero initialization'.

Experimental Evidence on Transfer Pricing

Directory of Open Access Journals (Sweden)

Tran Quoc H.

2016-06-01

Full Text Available We use incentivized economics experiments to test both the point predictions and comparative static predictions of optimal transfer pricing models, comparing behavior under varying conditions, including wholly versus partially-owned subsidiaries and different tariff and tax rates. As predicted, we find that transfer prices are responsive to relative tax and tariff rates as well as ownership proportions. Additionally, we examine convergence and learning in this setting. While individuals do not choose optimal transfer prices, their choices converge to optimal levels with experience. This paper thus makes two important contributions. First, by comparing behavior with theoretical predictions it provides evidence of whether (and when individuals set transfer prices optimally. Second, by comparing behavior under conditions of full and partial ownership it provides evidence on the impact of policy interventions (like regulating ownership proportions by MNEs on tax revenues.

Photorespiratory Bypasses Lead to Increased Growth in Arabidopsis thaliana: Are Predictions Consistent with Experimental Evidence?

Science.gov (United States)

Basler, Georg; Küken, Anika; Fernie, Alisdair R.; Nikoloski, Zoran

2016-01-01

Arguably, the biggest challenge of modern plant systems biology lies in predicting the performance of plant species, and crops in particular, upon different intracellular and external perturbations. Recently, an increased growth of Arabidopsis thaliana plants was achieved by introducing two different photorespiratory bypasses via metabolic engineering. Here, we investigate the extent to which these findings match the predictions from constraint-based modeling. To determine the effect of the employed metabolic network model on the predictions, we perform a comparative analysis involving three state-of-the-art metabolic reconstructions of A. thaliana. In addition, we investigate three scenarios with respect to experimental findings on the ratios of the carboxylation and oxygenation reactions of Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). We demonstrate that the condition-dependent growth phenotypes of one of the engineered bypasses can be qualitatively reproduced by each reconstruction, particularly upon considering the additional constraints with respect to the ratio of fluxes for the RuBisCO reactions. Moreover, our results lend support for the hypothesis of a reduced photorespiration in the engineered plants, and indicate that specific changes in CO2 exchange as well as in the proxies for co-factor turnover are associated with the predicted growth increase in the engineered plants. We discuss our findings with respect to the structure of the used models, the modeling approaches taken, and the available experimental evidence. Our study sets the ground for investigating other strategies for increase of plant biomass by insertion of synthetic reactions. PMID:27092301

The paradox of natural products as pharmaceuticals. Experimental evidences of a mango stem bark extract.

Science.gov (United States)

Núñez-Sellés, Alberto J; Delgado-Hernández, René; Garrido-Garrido, Gabino; García-Rivera, Dagmar; Guevara-García, Mariela; Pardo-Andreu, Gilberto L

2007-05-01

Recent findings regarding basic, pre-clinical and clinical studies on a mango stem bark extract (MSBE) developed in Cuba (Vimang) on an industrial scale are summarized. Ethnomedical studies, extract reproducibility, biological effects and clinical evaluations in terms of patient quality of life are described as experimental evidences to support the statement that natural products, even being a mixture of compounds, could be as effective as "monoceuticals" for medical uses. Discussion about the use of "monoceuticals" versus "natureceuticals" in health care and medicine is based on effectiveness and availability, taking Vimang as an example of a natural product with supported scientific evidence to be used as antioxidant, analgesic, anti-inflammatory and immunomodulator.

New experimental evidence of the diffusionless transformation nature of bainite

International Nuclear Information System (INIS)

Caballero, F.G.; Miller, M.K.; Garcia-Mateo, C.; Cornide, J.

2013-01-01

Highlights: ► A new generation of steels has been designed, which on transformation at low temperature (200–350 °C), lead to a nano-scale microstructure, known as NanoBain. The microstructure consists of slender crystals of ferrite, whose controlling scale compares well with that of carbon nanotubes (20–40 nm). ► NanoBain present the highest strength/toughness combinations ever recorded in bainitic steels (∼2.5 GPa/40 MPa m 1/2 ). This structure can be produced without any severe heat treatment, without deformation, simply by phase changes occurring slowly at low temperatures. ► The characterization of NanoBain at the atomic scale has led to revealed extremely important detail on the atomic mechanisms of phase transformations which have been controversial for the last seventy years. ► The results reported in this work have proven beyond doubt that the bainite phase change is essentially displacive in nature. -- Abstract: Since the discovery of bainite, research over many decades has revealed a substantial amount of information about the mechanism of the bainite transformation in steels. Elements of the theory are now routinely being used in many parts of the world in the design of novel alloys and in the interpretation of a variety of experimental data. However, current experimental and theoretical understanding is limiting technological progress. The purpose of this atom probe tomography study was to track atom distributions during the bainite reaction in a nanocrystalline steel. The results are providing new experimental evidence on subjects critically relevant to the understanding of the atomic mechanisms controlling bainitic ferrite formation, such as the incomplete transformation phenomenon, the carbon supersaturation of ferrite, and the plastic accommodation of the surrounding austenite

New experimental evidence of the diffusionless transformation nature of bainite

Energy Technology Data Exchange (ETDEWEB)

Caballero, F.G., E-mail: fgc@cenim.csic.es [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avda Gregorio del Amo, 8, Madrid, E-28040 (Spain); Miller, M.K. [Oak Ridge National Laboratory (ORNL), Materials Science and Technology Division, Oak Ridge, TN 37831-6136 (United States); Garcia-Mateo, C.; Cornide, J. [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avda Gregorio del Amo, 8, Madrid, E-28040 (Spain)

2013-11-15

Highlights: ► A new generation of steels has been designed, which on transformation at low temperature (200–350 °C), lead to a nano-scale microstructure, known as NanoBain. The microstructure consists of slender crystals of ferrite, whose controlling scale compares well with that of carbon nanotubes (20–40 nm). ► NanoBain present the highest strength/toughness combinations ever recorded in bainitic steels (∼2.5 GPa/40 MPa m{sup 1/2}). This structure can be produced without any severe heat treatment, without deformation, simply by phase changes occurring slowly at low temperatures. ► The characterization of NanoBain at the atomic scale has led to revealed extremely important detail on the atomic mechanisms of phase transformations which have been controversial for the last seventy years. ► The results reported in this work have proven beyond doubt that the bainite phase change is essentially displacive in nature. -- Abstract: Since the discovery of bainite, research over many decades has revealed a substantial amount of information about the mechanism of the bainite transformation in steels. Elements of the theory are now routinely being used in many parts of the world in the design of novel alloys and in the interpretation of a variety of experimental data. However, current experimental and theoretical understanding is limiting technological progress. The purpose of this atom probe tomography study was to track atom distributions during the bainite reaction in a nanocrystalline steel. The results are providing new experimental evidence on subjects critically relevant to the understanding of the atomic mechanisms controlling bainitic ferrite formation, such as the incomplete transformation phenomenon, the carbon supersaturation of ferrite, and the plastic accommodation of the surrounding austenite.

Smectite clays in Mars soil - Evidence for their presence and role in Viking biology experimental results

Science.gov (United States)

Banin, A.; Rishpon, J.

1979-01-01

Evidence for the presence of smectite clays in Martian soils is reviewed and results of experiments with certain active clays simulating the Viking biology experiments are reported. Analyses of Martian soil composition by means of X-ray fluorescence spectrometry and dust storm spectroscopy and Martian geological history strongly suggest the presence of a mixture of weathered ferro-silicate minerals, mainly nontronite and montmorillonite, accompanied by soluble sulphate salts, as major constituents. Samples of montmorillonite and nontronite incubated with (C-14)-formate or the radioactive nutrient medium solution used in the Viking Labeled Release experiment, were found to produce patterns of release of radioactive gas very similar to those observed in the Viking experiments, indicating the iron-catalyzed decomposition of formate as the reaction responsible for the Viking results. The experimental results of Hubbard (1979) simulating the results of the Viking Pyrolytic Release experiment using iron montmorillonites are pointed out, and it is concluded that many of the results of the Viking biology experiments can be explained in terms of the surface activity of smectite clays in catalysis and adsorption.

Experimental evidence that RNA recombination occurs in the Japanese encephalitis virus

International Nuclear Information System (INIS)

Chuang, C.-K.; Chen, W.-J.

2009-01-01

Due to the lack of a proofreading function and error-repairing ability of genomic RNA, accumulated mutations are known to be a force driving viral evolution in the genus Flavivirus, including the Japanese encephalitis (JE) virus. Based on sequencing data, RNA recombination was recently postulated to be another factor associated with genomic variations in these viruses. We herein provide experimental evidence to demonstrate the occurrence of RNA recombination in the JE virus using two local pure clones (T1P1-S1 and CJN-S1) respectively derived from the local strains, T1P1 and CJN. Based on results from a restriction fragment length polymorphism (RFLP) assay on the C/preM junction comprising a fragment of 868 nucleotides (nt 10-877), the recombinant progeny virus was primarily formed in BHK-21 cells that had been co-infected with the two clones used in this study. Nine of 20 recombinant forms of the JE virus had a crossover in the nt 123-323 region. Sequencing data derived from these recombinants revealed that no nucleotide deletion or insertion occurred in this region favoring crossovers, indicating that precisely, not aberrantly, homologous recombination was involved. With site-directed mutagenesis, three stem-loop secondary structures were destabilized and re-stabilized in sequence, leading to changes in the frequency of recombination. This suggests that the conformation, not the free energy, of the secondary structure is important in modulating RNA recombination of the virus. It was concluded that because RNA recombination generates genetic diversity in the JE virus, this must be considered particularly in studies of viral evolution, epidemiology, and possible vaccine safety.

Models of Investor Forecasting Behavior — Experimental Evidence

Directory of Open Access Journals (Sweden)

Federico Bonetto

2017-12-01

Full Text Available Different forecasting behaviors affect investors’ trading decisions and lead to qualitatively different asset price trajectories. It has been shown in the literature that the weights that investors place on observed asset price changes when forecasting future price changes, and the nature of their confidence when price changes are forecast, determine whether price bubbles, price crashes, and unpredictable price cycles occur. In this paper, we report the results of behavioral experiments involving multiple investors who participated in a market for a virtual asset. Our goal is to study investors’ forecast formation. We conducted three experimental sessions with different participants in each session. We fit different models of forecast formation to the observed data. There is strong evidence that the investors forecast future prices by extrapolating past price changes, even when they know the fundamental value of the asset exactly and the extrapolated forecasts differ significantly from the fundamental value. The rational expectations hypothesis seems inconsistent with the observed forecasts. The forecasting models of all participants that best fit the observed forecasting data were of the type that cause price bubbles and cycles in dynamical systems models, and price bubbles and cycles ended up occurring in all three sessions.

Design rules for piping: experimental validation of flexibility and elastic stress indices for elbows under bending

International Nuclear Information System (INIS)

Touboul, F.; Ben Jdidia, M.; Acker, D.

1989-01-01

Design rules for class 1 piping components are based on stress indices (B, C, K) and flexibility factors (k). For elbows, adjacent straight parts and internal pressure inhibit ovalization of the cross-section, so reducing the sub-mentioned indices. Published theoretical works and experimental results allow for improvement of coded values. End effect may be represented by a suitable function of the elbow angle. The favourable effect of pressure on C 2 , for fatigue damage evaluation, can be taken into account

Why Nudges Coerce: Experimental Evidence on the Architecture of Regulation.

Science.gov (United States)

Hill, Adam

2017-07-04

Critics frequently argue that nudges are more covert, less transparent, and more difficult to monitor than traditional regulatory tools. Edward Glaeser, for example, argues that "[p]ublic monitoring of soft paternalism is much more difficult than public monitoring of hard paternalism". As one of the leading proponents of soft paternalism, Cass Sunstein, acknowledges, while "[m]andates and commands are highly visible", soft paternalism, "and some nudges in particular[,] may be invisible". In response to this challenge, proponents of nudging argue that invisibility for any given individual in a particular choice environment is compatible with "careful public scrutiny" of the nudge. This paper offers the first of its kind experimental evidence that tests whether nudges are, in fact, compatible with "careful public scrutiny". Using three sets of experiments, the paper argues that, even when entirely visible, nudges attract less scrutiny than their "hard law" counterparts.

Scientific reasoning in early and middle childhood: the development of domain-general evidence evaluation, experimentation, and hypothesis generation skills.

Science.gov (United States)

Piekny, Jeanette; Maehler, Claudia

2013-06-01

According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation, and non-covariation evidence emerges, (b) when experimentation emerges, (c) when hypothesis generation skills emerge, and (d), whether these abilities develop synchronously during childhood. We administered three scientific reasoning tasks referring to the three components to 223 children of five age groups (from age 4.0 to 13.5 years). Our results show that the three cognitive components of domain-general scientific reasoning emerge asynchronously. The development of domain-general scientific reasoning begins with the ability to handle unambiguous data, progresses to the interpretation of ambiguous data, and leads to a flexible adaptation of hypotheses according to the sufficiency of evidence. When children understand the relation between the level of ambiguity of evidence and the level of confidence in hypotheses, the ability to differentiate conclusive from inconclusive experiments accompanies this development. Implications of these results for designing science education concepts for young children are briefly discussed. © 2012 The British Psychological Society.

Experimental evidence of an effective medium seen by diffuse light in turbid colloids

International Nuclear Information System (INIS)

Contreras-Tello, H; Garcia-Valenzuela, A

2011-01-01

The propagation of diffuse light in turbid media is usually modeled with radiative transfer theory. When diffuse light travelling in a turbid colloid is reflected and transmitted at a flat interface where there is a refractive index mismatch, it is not clear whether one should assume the incident diffuse-light is travelling in a medium with a refractive index equal to that of the background medium (usually referred to as the matrix) or if one should assume it travels in an effective medium. Most authors simply avoid this issue and most often use the refractive index of the matrix. While this might be a good approximation for dilute turbid media one may suspect that for highly scattering materials it may not be the case. In this work we investigate experimentally this issue. Our experimental results provide clear evidence that diffuse light inside the turbid colloid travels in an effective medium and not in the matrix.

Delayed school start times and adolescent sleep: A systematic review of the experimental evidence.

Science.gov (United States)

Minges, Karl E; Redeker, Nancy S

2016-08-01

Many schools have instituted later morning start times to improve sleep, academic, and other outcomes in response to the mismatch between youth circadian rhythms and early morning start times. However, there has been no systematic synthesis of the evidence on the effects of this practice. To examine the impact of delayed school start time on students' sleep, health, and academic outcomes, electronic databases were systematically searched and data were extracted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Six studies satisfied selection criteria and used pre-post, no control (n = 3), randomized controlled trial (n = 2), and quasi-experimental (n = 1) designs. School start times were delayed 25-60 min, and correspondingly, total sleep time increased from 25 to 77 min per weeknight. Some studies revealed reduced daytime sleepiness, depression, caffeine use, tardiness to class, and trouble staying awake. Overall, the evidence supports recent non-experimental study findings and calls for policy that advocates for delayed school start time to improve sleep. This presents a potential long-term solution to chronic sleep restriction during adolescence. However, there is a need for rigorous randomized study designs and reporting of consistent outcomes, including objective sleep measures and consistent measures of health and academic performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Is the anomalous effect an experimental evidence for the excitation of new exotic states in heavy-ion collisions

International Nuclear Information System (INIS)

Ion, D.B.; Ion, R.; Topor Pop, V.

1984-10-01

Lower bound on the mean free path of the projectile fragments from the relativistic heavy ion collisions are drived using generalized Rarita-Schwed's theorems. These bounds are compared with the experimental data on the anomalous mean free path observed in recent experiments. The near saturation of these bounds provide a specific interpretation of the anomalous effects as an experimental evidence for the excitation of those extreme nuclear states which saturate the limits of the convetional nuclear physics. (authors)

The broader economic impact of vaccination: reviewing and appraising the strength of evidence.

Science.gov (United States)

Jit, Mark; Hutubessy, Raymond; Png, May Ee; Sundaram, Neisha; Audimulam, Jananie; Salim, Safiyah; Yoong, Joanne

2015-09-03

Microeconomic evaluations of public health programmes such as immunisation typically only consider direct health benefits and medical cost savings. Broader economic benefits around childhood development, household behaviour, and macro-economic indicators are increasingly important, but the evidence linking immunization to such benefits is unclear. A conceptual framework of pathways between immunisation and its proposed broader economic benefits was developed through expert consultation. Relevant articles were obtained from previous reviews, snowballing, and expert consultation. Articles were associated with one of the pathways and quality assessed using modified Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. We found 20 studies directly relevant to one or more pathways. Evidence of moderate quality from experimental and observational studies was found for benefits due to immunisation in improved childhood physical development, educational outcomes, and equity in distribution of health gains. Only modelling evidence or evidence outside the immunization field supports extrapolating these benefits to household economic behaviour and macro-economic indicators. Innovative use of experimental and observational study designs is needed to fill evidence gaps around key pathways between immunisation and many of its proposed economic benefits.

The significance of secondary organic aerosol formation and growth in buildings: experimental and computational evidence

DEFF Research Database (Denmark)

Sarwar, G.; Corsi, R.; Allen, D.

2003-01-01

-pinene, and subsequent gas-to-particle partitioning of the products. A new indoor air quality model was used to predict dynamic particle mass concentrations based on detailed homogeneous chemical mechanisms and partitioning of semi-volatile products to particles. Chamber particle mass concentrations were estimated from......Experiments were conducted in an 11 m3 environmental chamber to investigate secondaryparticles resulting from homogeneous reactions between ozone and alpha-pinene. Experimental results indicate that rapid fine particle growth occurs due to homogeneous reactions between ozone and alpha...... measured particle size distributions and were in reasonable agreement with results predicted from the model. Both experimental and model results indicate that secondary particle mass concentrations incfrease substantially with lower air exchange rates. This is an interesting results, given a continuing...

Grading Gradients: Evaluating Evidence for Time-dependent Memory Reorganization in Experimental Animals

Directory of Open Access Journals (Sweden)

Katherine G. Akers

2009-01-01

Full Text Available In humans, hippocampal damage typically produces temporally graded retrograde amnesia, with relative sparing of remote memories compared to recent memories. This observation led to the idea that as memories age, they are reorganized in a time-dependent manner. Here, we evaluate evidence for time-dependent memory reorganization in animal models. We conclude that, although hippocampal lesions may not always produce temporal gradients under all conditions, studies using alternate experimental approaches consistently support the idea that memories reorganize over time—becoming less dependent on the hippocampus and more dependent on a cortical network. We further speculate on the processes that drive memory reorganization such as sleep, memory reactivation, synaptic plasticity, and neurogenesis.

The impact of free trial acceptance on demand for alternative nicotine products: evidence from experimental auctions.

Science.gov (United States)

Rousu, Matthew C; O'Connor, Richard J; Bansal-Travers, Maansi; Pitcavage, James M; Thrasher, James F

2015-06-11

This study explored the relationship between product trials and consumer demand for alternative nicotine products (ANP). An experimental auction was conducted with 258 adult smokers, wherein participants were randomly assigned to one of four experimental conditions. The participants received the opportunity to try, but did not have to accept, one of three relatively novel ST products (i.e., snus, dissolvable tobacco, or medicinal nicotine), or they were placed into a control group (i.e., no trial). All the participants then bid on all three of these products, as well as on cigarettes. We assessed interest in using ANP based on both trial of the product and bids placed for the products in the experimental auction. Fewer smokers were willing to try snus (44%) than dissolvable tobacco (64%) or medicine nicotine (68%). For snus, we find modest evidence suggesting that willingness to try is associated with greater demand for the product. For dissolvable tobacco or medicinal nicotine, we find no evidence that those who accept the product trial have higher demand for the product. Free trials of a novel ANP were not strongly associated with product demand, as assessed by willingness to pay. Given the debate over the potential for ANP to reduce the harm from smoking, these results are important in understanding the impact of free trial offers on adoption of ST product as a strategy to reduce harm from tobacco use.

Correlation between catalytic activity and bonding and coordination number of atoms and molecules on transition metal surfaces: theory and experimental evidence

International Nuclear Information System (INIS)

Falicov, L.M.; Somorjai, G.A.

1985-01-01

Correlation between catalytic activity and low-energy local electronic fluctuation in transition metals is proposed. A theory and calculations are presented which indicate that maximum electronic fluctuants take place at high-coordination metal sites. Either (i) atomically rough surfaces that expose to the reactant molecules atoms with large numbers of nonmagnetic or weakly magnetic neighbors in the first or second layer at the surface or (ii) stepped and kinked surfaces are the most active in carrying out structure-sensitive catalytic reactions. The synthesis of ammonia from N 2 and H 2 over iron and rhenium surfaces, 1 H 2 / 2 H 2 exchange over stepped platinum crystal surfaces at low pressures, and the hydrogenolysis (C - C bond breaking) of isobutane at kinked platinum crystal surfaces are presented as experimental evidence in support of the theory

Predicting the Unpredictable: 75 Years of Experimental Evidence

Science.gov (United States)

Radin, Dean I.

2011-11-01

From time immemorial, people have reported foreknowledge of future events. To determine whether such experiences are best understood via conventional explanations, or whether a retrocausal phenomenon might be involved in some instances, researchers have conducted hundreds of controlled laboratory experiments over the past 75 years. These studies fall into four general classes, and each class has generated repeatable evidence consistent with retrocausation. The statistical results for a class of forced-choice studies is associated with odds against chance of about 1024; for a class of free-response studies, odds about 1020; for psychophysiological-based studies, odds about 1017; and for implicit decision studies, odds about 1010. Effect sizes observed in the latter three classes are nearly identical, indicating replication of similar underlying effects. These effects are also in close agreement with the average effect size across 25,000 conventional social psychology experiments conducted over the last century, suggesting that retrocausal phenomena may not be especially unique, at least not in terms of the magnitude of effect. Bayesian analyses of the most recent classes of experiments confirm that the evidence is strongly in favor of a genuine effect, with Bayes Factors ranging from 13,669 to 1 for implicit decision experiments, to 2.9×1013 to 1 for psychophysiological designs. For the two most recent classes of studies examining retrocausal effects via unconscious physiological or behavioral measures, 85 of 101 studies (84%) reported by 25 different laboratories from the United States, Italy, Spain, Holland, Austria, Sweden, England, Scotland, Iran, Japan, and Australia, have produced results in the direction predicted by a retrocausal effect (odds against chance = 1.3×1012, via a sign test). Assessment of the methodologies used in these studies has not identified plausible conventional alternatives for the observed outcomes, suggesting the existence of a

Lecture 1: Experimental evidence for collective and thermal features in heavy ion reactions

International Nuclear Information System (INIS)

Moretto, L.G.

1979-01-01

The set of degrees of freedom playing a relevant role in deep inelastic processes is discussed. General considerations concerning the dynamic regimes prevailing during the nucleus--nucleus interaction lead to interesting conclusions regarding classical and quantal features as well as to the applicability of transport theories. The damping associated with the relative distance coordinate is considered and the evidence for thermal equilibrium between fragments is presented. The role of the E1 mode and of all the other odd isovector modes on the charge distrbution at fixed mass asymmetry is discussed and the posssible evidence for quantal fluctuations is analyzed. The mass asymmetry degree of freedom is considered in terms of the experimental mass distributions. The origin of the two components, deep inelastic and fusion--fission, is explained in terms of different dynamical regimes leading to greatly different interaction times. The rotational degrees of freedom are discussed in terms of γ-ray multiplicities and sequential fission. The problem of angular momentum fractionation along the mass asymmetry coordinate is considered and the depolarization and misalignment of the fragment spins are discussed. 43 references

Is the Readmission Rate a Valid Quality Indicator? A Review of the Evidence

Science.gov (United States)

Fischer, Claudia; Lingsma, Hester F.; Marang-van de Mheen, Perla J.; Kringos, Dionne S.; Klazinga, Niek S.; Steyerberg, Ewout W.

2014-01-01

Introduction Hospital readmission rates are increasingly used for both quality improvement and cost control. However, the validity of readmission rates as a measure of quality of hospital care is not evident. We aimed to give an overview of the different methodological aspects in the definition and measurement of readmission rates that need to be considered when interpreting readmission rates as a reflection of quality of care. Methods We conducted a systematic literature review, using the bibliographic databases Embase, Medline OvidSP, Web-of-Science, Cochrane central and PubMed for the period of January 2001 to May 2013. Results The search resulted in 102 included papers. We found that definition of the context in which readmissions are used as a quality indicator is crucial. This context includes the patient group and the specific aspects of care of which the quality is aimed to be assessed. Methodological flaws like unreliable data and insufficient case-mix correction may confound the comparison of readmission rates between hospitals. Another problem occurs when the basic distinction between planned and unplanned readmissions cannot be made. Finally, the multi-faceted nature of quality of care and the correlation between readmissions and other outcomes limit the indicator's validity. Conclusions Although readmission rates are a promising quality indicator, several methodological concerns identified in this study need to be addressed, especially when the indicator is intended for accountability or pay for performance. We recommend investing resources in accurate data registration, improved indicator description, and bundling outcome measures to provide a more complete picture of hospital care. PMID:25379675

Is the readmission rate a valid quality indicator? A review of the evidence.

Directory of Open Access Journals (Sweden)

Claudia Fischer

Full Text Available Hospital readmission rates are increasingly used for both quality improvement and cost control. However, the validity of readmission rates as a measure of quality of hospital care is not evident. We aimed to give an overview of the different methodological aspects in the definition and measurement of readmission rates that need to be considered when interpreting readmission rates as a reflection of quality of care.We conducted a systematic literature review, using the bibliographic databases Embase, Medline OvidSP, Web-of-Science, Cochrane central and PubMed for the period of January 2001 to May 2013.The search resulted in 102 included papers. We found that definition of the context in which readmissions are used as a quality indicator is crucial. This context includes the patient group and the specific aspects of care of which the quality is aimed to be assessed. Methodological flaws like unreliable data and insufficient case-mix correction may confound the comparison of readmission rates between hospitals. Another problem occurs when the basic distinction between planned and unplanned readmissions cannot be made. Finally, the multi-faceted nature of quality of care and the correlation between readmissions and other outcomes limit the indicator's validity.Although readmission rates are a promising quality indicator, several methodological concerns identified in this study need to be addressed, especially when the indicator is intended for accountability or pay for performance. We recommend investing resources in accurate data registration, improved indicator description, and bundling outcome measures to provide a more complete picture of hospital care.

Experimental and theoretical evidence for fluctuation driven activations in an excitable chemical system

Science.gov (United States)

Hastings, Harold; Sobel, Sabrina; Field, Richard; Minchenberg, Scott; Spinelli, Nicole; Zauderer, Keith

2011-03-01

An excitable medium is a system in which small perturbations die out, but sufficiently large perturbations generate large ``excitations.'' Biological examples include neurons and the heart; the latter supports waves of excitation normally generated by the sinus node, but occasionally generated by other mechanisms. The ferroin-catalyzed Belousov-Zhabotinsky reaction is the prototype chemical excitable medium. We present experimental and theoretical evidence for that random fluctuations can generate excitations in the Belousov-Zhabothinsky reaction. Although the heart is significantly different, there are some scaling analogies. This material is based upon work supported by the Department of Energy under Award Number DE-FG02-08ER64623.

The experimental status of neutrino masses and mixings

International Nuclear Information System (INIS)

Robertson, R.G.H.

1992-01-01

We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

Experimental evidence of a liquid-liquid transition in interfacial water

Science.gov (United States)

Zanotti, J.-M.; Bellissent-Funel, M.-C.; Chen, S.-H.

2005-07-01

At ambient pressure, bulk liquid water shows an anomalous increase of thermodynamic quantities and apparent divergences of dynamic properties on approaching a temperature Ts of 228 K. At normal pressure, supercooled water spontaneously freezes below the homogeneous nucleation temperature, TH = 235 K. Upon heating, the two forms of Amorphous Solid Water (ASW), LDA (Low Density Amorphous Ice) and HDA (High Density Amorphous Ice), crystallise above TX = 150 K. As a consequence, up to now no experiment has been able to explore the properties of liquid water in this very interesting temperature range between 150 and 235 K. We present nanosecond-time-scale measurements of local rotational and translational dynamics of interfacial, non-crystalline, water from 77 to 280 K. These experimental dynamic results are combined with calorimetric and diffraction data to show that after exhibiting a glass transition at 165 K, interfacial water experiences a first-order liquid-liquid transition at 240 K from a low-density to a high-density liquid. This is the first direct evidence of the existence of a liquid-liquid transition involving water.

Is the Internet making markets more efficient? The evidence according to price indicators in Spain

OpenAIRE

Sabaté i Garriga, Ferran; Cañabate Carmona, Antonio; Cobo Valeri, Erik; García, Dominie

2009-01-01

It has been theorized that low search costs associated with e-commerce imply greater levels of efficiency relative to the conventional retail channels. Multiple empirical studies confirm this hypothesis concerning price level, although the evidence is mixed relative to price dispersion. This article empirically compares the efficiency of the Internet with the conventional retail channel through 4 price indicators for the CD market. The results, based on 1,603 prices collected in Spain, are su...

The parasitic model of L2 and L3 vocabulary acquisition: evidence from naturalistic and experimental studies

Directory of Open Access Journals (Sweden)

Peter Ecke

2014-09-01

Full Text Available This paper reviews evidence for the Parasitic Model of Vocabulary Acquisition for second and third language learners/developing multilinguals. It first describes the model’s predictions about default processes based on the detection and use of similarity at the three stages involved in the development of individual lexical items: (1 the establishing of a form representation, (2 the building of connections to syntactic frame and concept representations, and (3 the strengthening and automatization of representations and access routes. The paper then summarizes both naturalistic and experimental evidence for processes involved at these three stages. Finally it discusses open issues and potential areas for future investigation.

Experimental evidence for a Mott-Wigner glass phase of magnetite above the Verwey temperature

International Nuclear Information System (INIS)

Boekema, C.; Lichti, R.L.; Chan, K.C.B.; Brabers, V.A.M.; Denison, A.B.; Cooke, D.W.; Heffner, R.H.; Hutson, R.L.; Schillaci, M.E.

1986-01-01

New muon-spin-relaxation (μSR) results on magnetite are reported and discussed in light of earlier Moessbauer, neutron, and μSR results. Modification of the μSR anomaly (observed at 247 K in zero field), when an external magnetic field is applied, provides evidence that the anomaly results from cross relaxation between the muon Larmor precession and the electron-correlation process in the B sublattice. The combined results strongly indicate that phonon-assisted electron hopping is the principal conduction mechanism above the Verwey transition temperature (T/sub V/). Together with theoretical evidence, these data support Mott's suggestion that above T/sub V/ magnetite is in the Wigner-glass state

Experimental evidence for the ancestry of allotetraploid Trifolium repens and creation of synthetic forms with value for plant breeding.

Science.gov (United States)

Williams, Warren M; Ellison, Nicholas W; Ansari, Helal A; Verry, Isabelle M; Hussain, S Wajid

2012-04-24

White clover (Trifolium repens) is a ubiquitous weed of the temperate world that through use of improved cultivars has also become the most important legume of grazed pastures world-wide. It has long been suspected to be allotetraploid, but the diploid ancestral species have remained elusive. Putative diploid ancestors were indicated by DNA sequence phylogeny to be T. pallescens and T. occidentale. Here, we use further DNA evidence as well as a combination of molecular cytogenetics (FISH and GISH) and experimental hybridization to test the hypothesis that white clover originated as a hybrid between T. pallescens and T. occidentale. T. pallescens plants were identified with chloroplast trnL intron DNA sequences identical to those of white clover. Similarly, T. occidentale plants with nuclear ITS sequences identical to white clover were also identified. Reciprocal GISH experiments, alternately using labeled genomic DNA probes from each of the putative ancestral species on the same white clover cells, showed that half of the chromosomes hybridized with each probe. F1 hybrids were generated by embryo rescue and these showed strong interspecific chromosome pairing and produced a significant frequency of unreduced gametes, indicating the likely mode of polyploidization. The F1 hybrids are inter-fertile with white clover and function as synthetic white clovers, a valuable new resource for the re-incorporation of ancestral genomes into modern white clover for future plant breeding. Evidence from DNA sequence analyses, molecular cytogenetics, interspecific hybridization and breeding experiments supports the hypothesis that a diploid alpine species (T. pallescens) hybridized with a diploid coastal species (T. occidentale) to generate tetraploid T. repens. The coming together of these two narrowly adapted species (one alpine and the other maritime), along with allotetraploidy, has led to a transgressive hybrid with a broad adaptive range.

Experimental evidence for the ancestry of allotetraploid Trifolium repens and creation of synthetic forms with value for plant breeding

Directory of Open Access Journals (Sweden)

Williams Warren M

2012-04-01

Full Text Available Abstract Background White clover (Trifolium repens is a ubiquitous weed of the temperate world that through use of improved cultivars has also become the most important legume of grazed pastures world-wide. It has long been suspected to be allotetraploid, but the diploid ancestral species have remained elusive. Putative diploid ancestors were indicated by DNA sequence phylogeny to be T. pallescens and T. occidentale. Here, we use further DNA evidence as well as a combination of molecular cytogenetics (FISH and GISH and experimental hybridization to test the hypothesis that white clover originated as a hybrid between T. pallescens and T. occidentale. Results T. pallescens plants were identified with chloroplast trnL intron DNA sequences identical to those of white clover. Similarly, T. occidentale plants with nuclear ITS sequences identical to white clover were also identified. Reciprocal GISH experiments, alternately using labeled genomic DNA probes from each of the putative ancestral species on the same white clover cells, showed that half of the chromosomes hybridized with each probe. F1 hybrids were generated by embryo rescue and these showed strong interspecific chromosome pairing and produced a significant frequency of unreduced gametes, indicating the likely mode of polyploidization. The F1 hybrids are inter-fertile with white clover and function as synthetic white clovers, a valuable new resource for the re-incorporation of ancestral genomes into modern white clover for future plant breeding. Conclusions Evidence from DNA sequence analyses, molecular cytogenetics, interspecific hybridization and breeding experiments supports the hypothesis that a diploid alpine species (T. pallescens hybridized with a diploid coastal species (T. occidentale to generate tetraploid T. repens. The coming together of these two narrowly adapted species (one alpine and the other maritime, along with allotetraploidy, has led to a transgressive hybrid with a

The impact of energy, agriculture, macroeconomic and human-induced indicators on environmental pollution: evidence from Ghana.

Science.gov (United States)

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2017-03-01

In this study, the impact of energy, agriculture, macroeconomic and human-induced indicators on environmental pollution from 1971 to 2011 is investigated using the statistically inspired modification of partial least squares (SIMPLS) regression model. There was evidence of a linear relationship between energy, agriculture, macroeconomic and human-induced indicators and carbon dioxide emissions. Evidence from the SIMPLS regression shows that a 1% increase in crop production index will reduce carbon dioxide emissions by 0.71%. Economic growth increased by 1% will reduce carbon dioxide emissions by 0.46%, which means that an increase in Ghana's economic growth may lead to a reduction in environmental pollution. The increase in electricity production from hydroelectric sources by 1% will reduce carbon dioxide emissions by 0.30%; thus, increasing renewable energy sources in Ghana's energy portfolio will help mitigate carbon dioxide emissions. Increasing enteric emissions by 1% will increase carbon dioxide emissions by 4.22%, and a 1% increase in the nitrogen content of manure management will increase carbon dioxide emissions by 6.69%. The SIMPLS regression forecasting exhibited a 5% MAPE from the prediction of carbon dioxide emissions.

A Health 'Kuznets' Curve'? Cross-Sectional and Longitudinal Evidence on Concentration Indices'.

Science.gov (United States)

Costa-Font, Joan; Hernandez-Quevedo, Cristina; Sato, Azusa

2018-01-01

The distribution of income related health inequalities appears to exhibit changing patterns when both developing countries and developed countries are examined. This paper tests for the existence of a health Kuznets' curve; that is, an inverse U-shape pattern between economic developments (as measured by GDP per capita) and income-related health inequalities (as measured by concentration indices). We draw upon both cross sectional (the World Health Survey) and a long longitudinal (the European Community Household Panel survey) dataset. Our results suggest evidence of a health Kuznets' curve on per capita income. We find a polynomial association where inequalities decline when GDP per capita reaches a magnitude ranging between $26,000 and $38,700. That is, income-related health inequalities rise with GDP per capita, but tail off once a threshold level of economic development has been attained.

Scientific Reasoning in Early and Middle Childhood: The Development of Domain-General Evidence Evaluation, Experimentation, and Hypothesis Generation Skills

Science.gov (United States)

Piekny, Jeanette; Maehler, Claudia

2013-01-01

According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation,…

Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

International Nuclear Information System (INIS)

O’Brien, Daniel B.; Massari, Aaron M.

2015-01-01

In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report

Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation.

Science.gov (United States)

O'Brien, Daniel B; Massari, Aaron M

2015-01-14

In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N'-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

Energy Technology Data Exchange (ETDEWEB)

O’Brien, Daniel B.; Massari, Aaron M., E-mail: massari@umn.edu [Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455 (United States)

2015-01-14

In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

Astragaloside IV for Experimental Focal Cerebral Ischemia: Preclinical Evidence and Possible Mechanisms

Directory of Open Access Journals (Sweden)

Hui-Lin Wang

2017-01-01

Full Text Available Astragaloside IV (AST-IV is a principal component of Radix Astragali seu Hedysari (Huangqi and exerts potential neuroprotection in experimental ischemic stroke. Here, we systematically assessed the effectiveness and possible mechanisms of AST-IV for experimental acute ischemic stroke. An electronic search in eight databases was conducted from inception to March 2016. The study quality score was evaluated using the CAMARADES. Rev Man 5.0 software was used for data analyses. Thirteen studies with 244 animals were identified. The study quality score of included studies ranged from 3/10 to 8/10. Eleven studies showed significant effects of AST-IV for ameliorating the neurological function score (P<0.05; seven studies for reducing the infarct volume (P<0.05; and three or two studies for reducing the brain water content and Evans blue leakage (P<0.05, respectively, compared with the control. The mechanisms of AST-IV for ischemic stroke are multiple such as antioxidative/nitration stress reaction, anti-inflammatory, and antiapoptosis. In conclusion, the findings of present study indicated that AST-IV could improve neurological deficits and infarct volume and reduce the blood-brain barrier permeability in experimental cerebral ischemia despite some methodological flaws. Thus, AST-IV exerted a possible neuroprotective effect during the cerebral ischemia/reperfusion injury largely through its antioxidant, anti-inflammatory, and antiapoptosis properties.

Experimental study on p-V indicator diagrams of twin-screw refrigeration compressor with economizer

International Nuclear Information System (INIS)

Wu Huagen; Peng Xueyuan; Xing Ziwen; Shu Pengcheng

2004-01-01

This paper presents the experimental investigation on the effects of the superfeed pressure together with economizer type on the performance of the twin-screw refrigeration compressor by means of the indicator diagram. With a pressure sensor embedded into the groove at the root of the female rotor on the discharge side, the pressure within the working chamber of a semi-hermetic twin-screw compressor with an economizer is recorded and then transformed into the indicator diagram. The results thus obtained are utilized to investigate the thermodynamic process of the compressor. It is shown that the compressor with an economizer has higher pressure during almost the whole compression process than without an economizer, resulting in the increase in the indicated power. Under different superfeed pressures, the pressure within the compression experiences different changes. This results in an optimal superfeed pressure for maximized compressor efficiency, which can be identified from the calculated compressor efficiency based on the indicator diagrams. It is also found that the pressure has a rapid increase at the beginning of superfeed process, and then a slow rise even a slight drop at the end of superfeed process, which is caused by the dynamic effect during superfeed process. Furthermore, if the superfeed pressure keeps the same, the pressure during compression in the compressor with the heat exchanger economizer is slightly higher than with the flash tank economizer, due to the higher temperature of superfeed refrigerant gas in the former case

Fostering Early Math Comprehension: Experimental Evidence from Paraguay

Directory of Open Access Journals (Sweden)

Emma Naslund-Hadley

2014-11-01

Full Text Available Research indicates that preschool children need to learn pre-math skills to build a foundation for primary- and secondary-level mathematics. This paper presents the results from the early stages of a pilot mathematics program implemented in Cordillera, Paraguay. In a context of significant gaps in teacher preparation and pedagogy, the program uses interactive audio segments that cover the entire preschool math curriculum. Since Paraguayan classrooms tend to be bilingual, the audio and written materials use a combination of Spanish and Guaraní. Based on an experimental evaluation since the program’s implementation, we document positive and significant improvements of 0.16 standard deviations in standardized test scores. The program helped narrow learning gaps between low- and high-performing students, and between students with trained teachers and those whose teachers lack formal training in early childhood education. Moreover, the program improved learning equally among both Guaraní- and Spanish-speaking students. But not all learning gaps narrowed as a result of the program. Although girls improved significantly, boys improved much more, ultimately increasing the gender gap. To close this gender gap, the program has been modified to encourage girls’ increased participation in the classroom and general interest in math

Experimental analysis of IMEP in a rotary combustion engine. [Indicated Mean Effective Pressure

Science.gov (United States)

Schock, H. J.; Rice, W. J.; Meng, P. R.

1981-01-01

This experimental work demonstrates the use of a NASA designed, real time Indicated Mean Effective Pressure (IMEP) measurement system which will be used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate the volume function in real time. Measurements at two engine speeds (2000 and 3000 RPM) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 RPM.

Website quality indicators for consumers.

Science.gov (United States)

Griffiths, Kathleen M; Christensen, Helen

2005-11-15

The rating tool DISCERN was designed for use by consumers without content expertise to evaluate the quality of health information. There is some evidence that DISCERN may be a valid indicator of evidence-based website quality when applied by health professionals. However, it is not known if the tool is a valid measure of evidence-based quality when used by consumers. Since it is a lengthy instrument requiring training in its use, DISCERN may prove impractical for use by the typical consumer. It is therefore important to explore the validity of other simpler potential indicators of site quality such as Google PageRank. This study aimed to determine (1) whether the instrument DISCERN is a valid indicator of evidence-based Web content quality for consumers without specific mental health training, and (2) whether Google PageRank is an indicator of website content quality as measured by an evidence-based gold standard. This was a cross-sectional survey of depression websites using consumer and health professional raters. The main outcome measures were (1) site characteristics, (2) evidence-based quality of content as measured by evidence-based depression guidelines, (3) DISCERN scores, (4) Google PageRank, and (5) user satisfaction. There was a significant association between evidence-based quality ratings and average DISCERN ratings both for consumers (r = 0.62, P = .001) and health professionals (r = 0.80, P PageRank (r = 0.59, P = .002). However, the correlation between DISCERN scores and user satisfaction was higher than the correlation between Google PageRank and user satisfaction. DISCERN has potential as an indicator of content quality when used either by experts or by consumers. Google PageRank shows some promise as an automatic indicator of quality.

Using the Theoretical Domains Framework (TDF) to understand adherence to multiple evidence-based indicators in primary care: a qualitative study.

Science.gov (United States)

Lawton, Rebecca; Heyhoe, Jane; Louch, Gemma; Ingleson, Emma; Glidewell, Liz; Willis, Thomas A; McEachan, Rosemary R C; Foy, Robbie

2016-08-08

There are recognised gaps between evidence and practice in general practice, a setting posing particular implementation challenges. We earlier screened clinical guideline recommendations to derive a set of 'high-impact' indicators based upon criteria including potential for significant patient benefit, scope for improved practice and amenability to measurement using routinely collected data. Here, we explore health professionals' perceived determinants of adherence to these indicators, examining the degree to which determinants were indicator-specific or potentially generalisable across indicators. We interviewed 60 general practitioners, practice nurses and practice managers in West Yorkshire, the UK, about adherence to four indicators: avoidance of risky prescribing; treatment targets in type 2 diabetes; blood pressure targets in treated hypertension; and anticoagulation in atrial fibrillation. Interview questions drew upon the Theoretical Domains Framework (TDF). Data were analysed using framework analysis. Professional role and identity and environmental context and resources featured prominently across all indicators whilst the importance of other domains, for example, beliefs about consequences, social influences and knowledge varied across indicators. We identified five meta-themes representing more general organisational and contextual factors common to all indicators. The TDF helped elicit a wide range of reported determinants of adherence to 'high-impact' indicators in primary care. It was more difficult to pinpoint which determinants, if targeted by an implementation strategy, would maximise change. The meta-themes broadly underline the need to align the design of interventions targeting general practices with higher level supports and broader contextual considerations. However, our findings suggest that it is feasible to develop interventions to promote the uptake of different evidence-based indicators which share common features whilst also including

Cardiovascular autonomic dysfunction in primary ovarian insufficiency: clinical and experimental evidence

Science.gov (United States)

Goldmeier, Silvia; De Angelis, Kátia; Rabello Casali, Karina; Vilodre, César; Consolim-Colombo, Fernanda; Belló Klein, Adriane; Plentz, Rodrigo; Spritzer, PoliMara; Irigoyen, Maria-Cláudia

2014-01-01

Objective: Women with primary ovarian insufficiency (POI) present an increased risk for cardiovascular disease. In this study we tested the hypothesis that POI in women under hormone therapy (HT) are associated with vascular vasodilatation attenuation and cardiovascular autonomic dysfunction and these impairments are related to changes in systemic antioxidant enzymes. Furthermore, the possibility that ovarian hormone deprivation can induce such changes and that HT cannot reverse all of those impairments was examined in an experimental model of POI. Methods: Fifteen control and 17 patients with primary ovarian insufficiency receiving HT were included in the study. To test the systemic and cardiac consequences of ovarian hormone deprivation, ovariectomy was induced in young female rats that were submitted or not to HT. Spectral analysis of RR interval and blood pressure signals were performed and oxidative stress parameters were determined. Results: POI women under HT have increased mean arterial pressure (94±10 vs. 86±5 mmHg) despite normal endothelial and autonomic modulation of vasculature. Additionally, they presented impaired baroreflex sensitivity (3.9±1.38 vs. 7.15±3.62 ms/mmHg) and reduced heart rate variability (2310±1173 vs. 3754±1921 ms2). Similar results obtained in ovariectomized female rats were accompanied by an increased lipoperoxidation (7433±1010 vs. 6180±289 cps/mg protein) and decreased antioxidant enzymes in cardiac tissue. As it was observed in women, the HT in animals did not restore hemodynamic and autonomic dysfunctions. Conclusion: These data provide clinical and experimental evidence that long term HT may not restore all cardiovascular risk factors associated with ovarian hormone deprivation. PMID:24349626

Isomer depletion as experimental evidence of nuclear excitation by electron capture

Science.gov (United States)

Chiara, C. J.; Carroll, J. J.; Carpenter, M. P.; Greene, J. P.; Hartley, D. J.; Janssens, R. V. F.; Lane, G. J.; Marsh, J. C.; Matters, D. A.; Polasik, M.; Rzadkiewicz, J.; Seweryniak, D.; Zhu, S.; Bottoni, S.; Hayes, A. B.; Karamian, S. A.

2018-02-01

The atomic nucleus and its electrons are often thought of as independent systems that are held together in the atom by their mutual attraction. Their interaction, however, leads to other important effects, such as providing an additional decay mode for excited nuclear states, whereby the nucleus releases energy by ejecting an atomic electron instead of by emitting a γ-ray. This ‘internal conversion’ has been known for about a hundred years and can be used to study nuclei and their interaction with their electrons. In the inverse process—nuclear excitation by electron capture (NEEC)—a free electron is captured into an atomic vacancy and can excite the nucleus to a higher-energy state, provided that the kinetic energy of the free electron plus the magnitude of its binding energy once captured matches the nuclear energy difference between the two states. NEEC was predicted in 1976 and has not hitherto been observed. Here we report evidence of NEEC in molybdenum-93 and determine the probability and cross-section for the process in a beam-based experimental scenario. Our results provide a standard for the assessment of theoretical models relevant to NEEC, which predict cross-sections that span many orders of magnitude. The greatest practical effect of the NEEC process may be on the survival of nuclei in stellar environments, in which it could excite isomers (that is, long-lived nuclear states) to shorter-lived states. Such excitations may reduce the abundance of the isotope after its production. This is an example of ‘isomer depletion’, which has been investigated previously through other reactions, but is used here to obtain evidence for NEEC.

Some kinetic and spectroscopic evidence on intramolecular relaxation processes in polyatomic molecules

International Nuclear Information System (INIS)

Quack, M.

1983-01-01

The description and definition of intramolecular vibrational relaxation processes is discussed within the framework of the quantum mechanical and statistical mechanical equations of motion. The evidence from quite different experimental sources is summarized under the common aspect of vibrational relaxation. Although much of the evidence remains ambiguous, there is good indication that a localized vibrational excitation relaxes typically in 0.1 to 10 picoseconds, which is long compared to many optical and reactive processes

Live Fast, Die Young: Experimental Evidence of Population Extinction Risk due to Climate Change

Science.gov (United States)

Bestion, Elvire; Teyssier, Aimeric; Richard, Murielle; Clobert, Jean; Cote, Julien

2015-01-01

Evidence has accumulated in recent decades on the drastic impact of climate change on biodiversity. Warming temperatures have induced changes in species physiology, phenology, and have decreased body size. Such modifications can impact population dynamics and could lead to changes in life cycle and demography. More specifically, conceptual frameworks predict that global warming will severely threaten tropical ectotherms while temperate ectotherms should resist or even benefit from higher temperatures. However, experimental studies measuring the impacts of future warming trends on temperate ectotherms' life cycle and population persistence are lacking. Here we investigate the impacts of future climates on a model vertebrate ectotherm species using a large-scale warming experiment. We manipulated climatic conditions in 18 seminatural populations over two years to obtain a present climate treatment and a warm climate treatment matching IPCC predictions for future climate. Warmer temperatures caused a faster body growth, an earlier reproductive onset, and an increased voltinism, leading to a highly accelerated life cycle but also to a decrease in adult survival. A matrix population model predicts that warm climate populations in our experiment should go extinct in around 20 y. Comparing our experimental climatic conditions to conditions encountered by populations across Europe, we suggest that warming climates should threaten a significant number of populations at the southern range of the distribution. Our findings stress the importance of experimental approaches on the entire life cycle to more accurately predict population and species persistence in future climates. PMID:26501958

Bridging Ayurveda with evidence-based scientific approaches in medicine.

Science.gov (United States)

Patwardhan, Bhushan

2014-01-01

This article reviews contemporary approaches for bridging Ayurveda with evidence-based medicine. In doing so, the author presents a pragmatic assessment of quality, methodology and extent of scientific research in Ayurvedic medicine. The article discusses the meaning of evidence and indicates the need to adopt epistemologically sensitive methods and rigorous experimentation using modern science. The author critically analyzes the status of Ayurvedic medicine based on personal observations, peer interactions and published research. This review article concludes that traditional knowledge systems like Ayurveda and modern scientific evidence-based medicine should be integrated. The author advocates that Ayurvedic researchers should develop strategic collaborations with innovative initiatives like 'Horizon 2020' involving predictive, preventive and personalized medicine (PPPM).

Gluconeogenesis in the ruminant fetus: evaluation of conflicting evidence from radiotracer and other experimental techniques

International Nuclear Information System (INIS)

Prior, R.L.

1982-01-01

Conflicting evidence exists as to whether the gluconeogenetic process is active in the late gestation fetal lamb. In vitro evidence based on measurements of enzyme activity and substrate flux into glucose indicates that the capacity for gluconeogenesis exists in fetal liver. The in vivo conversion of [ 14 C]lactate and [ 14 C]alanine into glucose in the lamb fetus has been demonstrated. Lactate and alanine account for 49 and 2.3% of the fetal glucose pool, respectively. Although gluconeogenesis can occur in the fetal lamb, alterations in net rates of umbilical uptake of glucose or lactate, fetal blood glucose concentrations, fetal or maternal glucose replacement rates, or maternal nutrition may alter the observed rates of fetal gluconeogenesis

Experimental evidence of infrared scintillation in crystals

CERN Document Server

Belogurov, S; Carugno, Giovanni; Conti, E; Iannuzzi, D; Meneguzzo, Anna Teresa

2000-01-01

We present experimental results on infrared emission induced by protons in some solid-state samples. Infrared scintillation occurs in many crystals, with different yield values and time-response behaviours. A rough measurement of the emission wavelength of CsI(Tl) is also reported.

Experimental Evidence for Abiotic Sulfurization of Marine Dissolved Organic Matter

Directory of Open Access Journals (Sweden)

Anika M. Pohlabeln

2017-11-01

Full Text Available Dissolved organic sulfur (DOS is the largest pool of organic sulfur in the oceans, and as such it is an important component of the global sulfur cycle. DOS in the ocean is resistant against microbial degradation and turns over on a millennium time scale. However, sources and mechanisms behind its stability are largely unknown. Here, we hypothesize that in sulfate-reducing sediments sulfur is abiotically incorporated into dissolved organic matter (DOM and released to the ocean. We exposed natural seawater and the filtrate of a plankton culture to sulfidic conditions. Already after 1-h at 20°C, DOS concentrations had increased 4-fold in these experiments, and 14-fold after 4 weeks at 50°C, indicating that organic matter does not need long residence times in natural sulfidic environments to be affected by sulfurization. Molecular analysis via ultrahigh-resolution mass spectrometry showed that sulfur was covalently and unselectively bound to DOM. Experimentally produced and natural DOS from sediments were highly similar on a molecular and structural level. By combining our data with published benthic DOC fluxes we estimate that 30–200 Tg DOS are annually transported from anaerobic and sulfate reducing sediments to the oceans. Uncertainties in this first speculative assessment are large. However, this first attempt illustrates that benthic DOS flux is potentially one order of magnitude larger than that via rivers indicating that this could balance the estimated global net removal of refractory DOS.

Decompression to altitude: assumptions, experimental evidence, and future directions.

Science.gov (United States)

Foster, Philip P; Butler, Bruce D

2009-02-01

Although differences exist, hypobaric and hyperbaric exposures share common physiological, biochemical, and clinical features, and their comparison may provide further insight into the mechanisms of decompression stress. Although altitude decompression illness (DCI) has been experienced by high-altitude Air Force pilots and is common in ground-based experiments simulating decompression profiles of extravehicular activities (EVAs) or astronauts' space walks, no case has been reported during actual EVAs in the non-weight-bearing microgravity environment of orbital space missions. We are uncertain whether gravity influences decompression outcomes via nitrogen tissue washout or via alterations related to skeletal muscle activity. However, robust experimental evidence demonstrated the role of skeletal muscle exercise, activities, and/or movement in bubble formation and DCI occurrence. Dualism of effects of exercise, positive or negative, on bubble formation and DCI is a striking feature in hypobaric exposure. Therefore, the discussion and the structure of this review are centered on those highlighted unresolved topics about the relationship between muscle activity, decompression, and microgravity. This article also provides, in the context of altitude decompression, an overview of the role of denitrogenation, metabolic gases, gas micronuclei, stabilization of bubbles, biochemical pathways activated by bubbles, nitric oxide, oxygen, anthropometric or physiological variables, Doppler-detectable bubbles, and potential arterialization of bubbles. These findings and uncertainties will produce further physiological challenges to solve in order to line up for the programmed human return to the Moon, the preparation for human exploration of Mars, and the EVAs implementation in a non-zero gravity environment.

Output commitment through product bundling : Experimental evidence

NARCIS (Netherlands)

Hinloopen, Jeroen; Mueller, Wieland; Normann, Hans-Theo

We analyze the impact of product bundling in experimental markets. One firm has monopoly power in a first market but competes with another firm la Cournot in a second market. We compare treatments where the multi-product firm (i) always bundles, (ii) never bundles, and (iii) chooses whether to

Output commitment through product bundling: experimental evidence

NARCIS (Netherlands)

Hinloopen, J.; Mueller, W.; Normann, H.T.

2011-01-01

We analyze the impact of product bundling in experimental markets. A firm has monopoly power in one market but faces competition by a second firm in another market. We compare treatments where the monopolist can bundle its two products to treatments where it cannot, and we contrast simultaneous and

Proprioceptive dysfunction in focal dystonia: from experimental evidence to rehabilitation strategies.

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Laura eAvanzino

2014-12-01

Full Text Available Dystonia has historically been considered a disorder of the basal ganglia, mainly affecting planning and execution of voluntary movements. This notion comes from the observation that most lesions responsible for secondary dystonia involve the basal ganglia. However, what emerges from recent research is that dystonia is linked to the dysfunction of a complex neural network that comprises basal ganglia-thalamic-frontal cortex, but also the inferior parietal cortex and the cerebellum. While dystonia is clearly a motor problem, it turned out that sensory aspects are also fundamental, especially those related to proprioception.We outline experimental evidence for proprioceptive dysfunction in focal dystonia from intrinsic sensory abnormalities to impaired sensorimotor integration, that is the process by which sensory information is used to plan and execute volitional movements. Particularly, we will focus on proprioceptive aspects of dystonia, including: i processing of vibratory input, ii temporal discrimination of two passive movements, iii multimodal integration of visual-tactile and proprioceptive inputs and, iv motor control in the absence of visual feedback. We suggest that these investigations contribute not only to a better understanding of dystonia pathophysiology, but also to develop rehabilitation strategies aimed at facilitating the processing of proprioceptive input.

Quality indicators

DEFF Research Database (Denmark)

Hjorth-Andersen, Christian

1991-01-01

In recent literature it has been suggested that consumers need have no knowledge of product quality as a number of quality indicators (or signals) may be used as substitutes. Very little attention has been paid to the empirical verification of these studies. The present paper is devoted...... to the issue of how well these indicators perform, using market data provided by consumer magazines from 3 countries. The results strongly indicate that price is a poor quality indicator. The paper also presents some evidence which suggests that seller reputation and easily observable characteristics are also...

Quarks, QCD [quantum chromodynamics] and the real world of experimental data

International Nuclear Information System (INIS)

Lipkin, H.J.

1987-07-01

The experimental evidence that supports quantum chromodynamics as the theory that describes how the quarks interact is briefly discussed. The indications of the existence of quarks are reviewed, and calculation of hadron masses is discussed. Additional evidence of hadron substructure as seen in the antiproton is reviewed. Arguments for the existence of color as the ''charge'' carried by quarks by which they interact are given. Hadron masses and the hyperfine interaction are presented, followed by more exotic quark systems and a study of multiquark systems. Weak interactions in the quark model are discussed

An experimental study of the job demand-control model with measures of heart rate variability and salivary alpha-amylase: Evidence of increased stress responses to increased break autonomy.

Science.gov (United States)

O'Donnell, Emma; Landolt, Kathleen; Hazi, Agnes; Dragano, Nico; Wright, Bradley J

2015-01-01

We assessed in an experimental design whether the stress response towards a work task was moderated by the autonomy to choose a break during the assigned time to complete the task. This setting is defined in accordance with the theoretical framework of the job-demand-control (JDC) model of work related stress. The findings from naturalistic investigations of a stress-buffering effect of autonomy (or 'buffer hypothesis') are equivocal and the experimental evidence is limited, especially with relation to physiological indices of stress. Our objective was to investigate if increased autonomy in a particular domain (break time control) was related with adaptive physiology using objective physiological markers of stress; heart rate variability (HRV) and salivary alpha amylase (sAA). We used a within-subject design and the 60 female participants were randomly assigned to an autonomy (free timing of break) and standard conditions (fixed timing of break) of a word processing task in a simulated office environment in a random order. Participants reported increased perceptions of autonomy, no difference in demand and performed worse in the task in the break-time autonomy versus the standard condition. The results revealed support for the manipulation of increased autonomy, but in the opposing direction. Increased autonomy was related with dysregulated physiological reactivity, synonymous with typical increased stress responses. Potentially, our findings may indicate that autonomy is not necessary a resource but could become an additional stressor when it adds additional complexity while the amount of work (demands) remains unchanged. Further, our findings underscore the need to collect objective physiological evidence of stress to supplement self-reported information. Self-report biases may partially explain the inconsistent findings with the buffer hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Are glendonites reliable indicators of cold conditions? Evidence from the Lower Cretaceous of Spitsbergen

Science.gov (United States)

Vickers, Madeleine; Price, Gregory; Watkinson, Matthew; Jerrett, Rhodri

2017-04-01

Glendonites are pseudomorphs after the mineral ikaite, and have been found in marine sediments throughout geological time. Ikaite is a metastable, hydrated form of calcium carbonate, which is only stable under specific conditions: between -2 and +5 °C, and with high alkalinity and phosphate concentrations. Glendonites are often associated with cold climates due to the strong temperature control on ikaite growth, and the coincidence in the geological record with episodes of global cooling. Glendonites are found in the Lower Cretaceous succession in Spitsbergen. During the Early Cretaceous, Spitsbergen was at a palaeolatitude of 60°N, and was part of a shallow epicontinental sea that formed during the Mesozoic as Atlantic rifting propagated northwards. Though the Early Cretaceous was generally characterised by greenhouse climate conditions, episodic cold snaps occurred during the Valanginian (the "Weissert Event") and during Aptian-Albian. Using high resolution carbon-isotope stratigraphy, we show that the first occurrences of glendonites are in the upper Lower Hauterivian and in the very upper Upper Hauterivian, stratigraphically higher than the Valanginian cooling event. Glendonites are also found in horizons in the Upper Aptian, coincident with the Aptian-Albian cold snap. Petrological analysis of the glendonite structure reveals differences between the Hauterivian and Aptian glendonites, with evidence for multiple diagenetic phases of growth in the Hauterivian glendonites, suggesting oscillating chemical conditions. This evidence suggests that local environmental conditions may have a stronger control on glendonite formation and preservation than global climate. We present a new model for ikaite growth and slow transformation to glendonite in marine sediments, which points to a more complex suite of diagenetic transformations than previously modelled. Furthermore, we critically assess whether such pseudomorphs after marine sedimentary ikaite may be indicators

Currency Crisis and Contagion; Evidence From Exchange Rates and Sectoral Stock Indices of the Philippines and Thailand

OpenAIRE

Jun Nagayasu

2000-01-01

This paper analyzes empirically the recent Asian financial crisis using high frequency data of exchange rates and stock indices of the Philippines and Thailand. Utilizing standard time-series techniques, this study confirms that there is evidence that developments in some sectoral indices—including those of banking and financial sectors—seem to have caused upward pressure on exchange rates. A correlation between some of these variables is also found to be strong across countries in the crisis...

Gender differences in cooperation: experimental evidence on high school students.

Directory of Open Access Journals (Sweden)

J Alberto Molina

Full Text Available The emergence of cooperation among unrelated human subjects is a long-standing conundrum that has been amply studied both theoretically and experimentally. Within the question, a less explored issue relates to the gender dependence of cooperation, which can be traced back to Darwin, who stated that "women are less selfish but men are more competitive". Indeed, gender has been shown to be relevant in several game theoretical paradigms of social cooperativeness, including prisoner's dilemma, snowdrift and ultimatum/dictator games, but there is no consensus as to which gender is more cooperative. We here contribute to this literature by analyzing the role of gender in a repeated Prisoners' Dilemma played by Spanish high-school students in both a square lattice and a heterogeneous network. While the experiment was conducted to shed light on the influence of networks on the emergence of cooperation, we benefit from the availability of a large dataset of more 1200 participants. We applied different standard econometric techniques to this dataset, including Ordinary Least Squares and Linear Probability models including random effects. All our analyses indicate that being male is negatively associated with the level of cooperation, this association being statistically significant at standard levels. We also obtain a gender difference in the level of cooperation when we control for the unobserved heterogeneity of individuals, which indicates that the gender gap in cooperation favoring female students is present after netting out this effect from other socio-demographics factors not controlled for in the experiment, and from gender differences in risk, social and competitive preferences.

Experimental evidence for the involvement of dinuclear alkynylcopper(I) complexes in alkyne-azide chemistry.

Science.gov (United States)

Buckley, Benjamin R; Dann, Sandra E; Heaney, Harry

2010-06-01

Dinuclear alkynylcopper(I) ladderane complexes are prepared by a robust and simple protocol involving the reduction of Cu(2)(OH)(3)OAc or Cu(OAc)(2) by easily oxidised alcohols in the presence of terminal alkynes; they function as efficient catalysts in copper-catalysed alkyne-azide cycloaddition reactions as predicted by the Ahlquist-Fokin calculations. The same copper(I) catalysts are formed during reactions by using the Sharpless-Fokin protocol. The experimental results also provide evidence that sodium ascorbate functions as a base to deprotonate terminal alkynes and additionally give a convincing alternative explanation for the fact that the Cu(I)-catalysed reactions of certain 1,3-diazides with phenylacetylene give bis(triazoles) as the major products. The same dinuclear alkynylcopper(I) complexes also function as catalysts in cycloaddition reactions of azides with 1-iodoalkynes.

Violation of specific indicators pigment and lipid metabolism in experimental pneumonia in an immobilization stress and correction of corvitin

Directory of Open Access Journals (Sweden)

N. M. Ferenc

2015-09-01

  Abstract   The aim of study was to investigate the features change cholesterol and bilirubin in the blood serum of guinea pigs (males with experimental pneumonia (EP under conditions of immobilization stress (IS and prove the feasibility of Corvitin. The study was conducted on 48 guinea pigs (males were divided into 6 groups. The research results make it possible to detect liver damage in terms of IS EP and in violation of its functional state. Application domestic preparation Corvitin led to a significant reduction in the changed parameters bilirubin and cholesterol under conditions of formation of EP and IP, which indicates its positive corrective effect.   Keywords: experimental pneumonia, stress, liver, cholesterol, bilirubin.

Pressure Ulcers: Developing Clinical Indicators in Evidence-based Practice. A Prospective Study.

Science.gov (United States)

Tsaras, Konstantinos; Chatzi, Maria; Kleisiaris, Christos F; Fradelos, Evangelos C; Kourkouta, Lambrini; Papathanasiou, Ioanna V

2016-10-01

It is widely recognized that Intensive Care Unit (ICU) patients have a greater likelihood of developing pressure ulcers in comparison to hospital or home care patients. Accordingly, this study aimed to evaluate whether specific clinical characteristics could be used as clinical indicators towards pressure ulcers prevention. We monitored 210 hospitalized ICU patients during a 12-month period. Pressure ulcers were assessed following the current guidelines. Clinical characteristics such as gender, age, hospitalized days, hemodialysis treatment, hematocrit, and serum albumin levels were considered as the most common predictors for pressure ulcers development. The significance of associations was controlled using multiple logistic regression after adjusting for clinical characteristics and was presented as adjusted odds ratio (AOR). The prevalence of pressure ulcers was 24.3%. Logistic regression revealed that patients with increased age AOR=1.04; (CI: 1.01-1.07) and last-long hospitalization AOR=1.17; (CI: 1.11-1.23) were significantly more likely to present pressure ulcers compared to the younger ones and patients with less length of stay, respectively. We also found that patients under hemodialysis treatment were more likely to present pressure ulcers AOR=4.09; (CI: 1.12-14.98) compared to patients that did not underwent hemodialysis and the risk of pressure ulcers development was decreased by 9% for every single unit of hematocrit value increase AOR=0.91; (CI: 0.82-0.99). Our data analysis confirms that the clinical characteristics that were studied are independently associated with pressure ulcers development, and therefore, it is a crucial incentive to consider that these specific clinical characteristics are important indicators in the evidence-based practice.

Secondary school physics teachers' conceptions of scientific evidence: A collective case study

Science.gov (United States)

Taylor, Joseph A.

Engaging secondary school students in inquiry-oriented tasks that more closely simulate the scholarly activities of scientists has been recommended as a way to improve scientific literacy. Two tasks that are frequently recommended include students' design of original experiments, and students' evaluation of scientific evidence and conclusions. Yet, little is known about teachers' conceptions of experimentation. The principal aim of this study, therefore, was to describe the nature of prospective and practicing physics teachers' conceptions of scientific evidence. More specifically, the following research questions guided this study: (1) What types of issues related to the measurement reliability and experimental validity of scientific evidence do practicing and prospective physics teachers think about when designing experiments? (2) When presented with hypothetical scenarios that describe unsound experimental procedures or poorly supported conclusions (or both), what concerns will prospective and practicing physics teachers raise? And (3) When the participants' responses to parallel research prompts are compared across protocols, what similarities and differences exist? The nature of the teacher-participants' conceptions was described from an analysis of data collected from research prompts such as interviews and hand written artifacts. In these research prompts, the teachers "thought aloud" while designing experiments and critically evaluated student-collected evidence presented in hypothetical classroom scenarios. The data from this study suggested that the three teachers, while contemplating the reliability and validity of scientific evidence, frequently used their conceptions of evidence in conjunction with specific subject matter conceptions. The data also indicated that the relationship between subject matter knowledge and conceptions of evidence was more pronounced for some conceptions of evidence than for others. Suggestions for future research included

Essays in the Economics of Corruption: Experimental and empirical evidence

OpenAIRE

Leszczynska, Nastassia

2018-01-01

The advent of experimental methodologies have led to decisive progress in the study of corrupt behaviour in the last two decades. Since they can complement survey data and perception indexes with controlled experimental data, scholars and policy makers have reached a better understanding of decision-making in bribery situations and are able to design innovative anticorruption policies.In this thesis, I use experimental and empirical data to contribute to the field of the economics of corrupti...

Experimental Evidence for Quantum Tunneling Time

Science.gov (United States)

Camus, Nicolas; Yakaboylu, Enderalp; Fechner, Lutz; Klaiber, Michael; Laux, Martin; Mi, Yonghao; Hatsagortsyan, Karen Z.; Pfeifer, Thomas; Keitel, Christoph H.; Moshammer, Robert

2017-07-01

The first hundred attoseconds of the electron dynamics during strong field tunneling ionization are investigated. We quantify theoretically how the electron's classical trajectories in the continuum emerge from the tunneling process and test the results with those achieved in parallel from attoclock measurements. An especially high sensitivity on the tunneling barrier is accomplished here by comparing the momentum distributions of two atomic species of slightly deviating atomic potentials (argon and krypton) being ionized under absolutely identical conditions with near-infrared laser pulses (1300 nm). The agreement between experiment and theory provides clear evidence for a nonzero tunneling time delay and a nonvanishing longitudinal momentum of the electron at the "tunnel exit."

An Evidence-Based Review Literature About Risk Indicators and Management of Unknown-Origin Xerostomia

Directory of Open Access Journals (Sweden)

Farzaneh Agha-hosseini

2013-01-01

Full Text Available Objective: This evidence-based article reviews risk indicators and management of unknown-origin xerostomia. Xerostomia and hyposalivation refer to different aspects of dry mouth. Xerostomia is a subjective sensation of dry mouth, whilst hyposalivation is defined as an objective assessment of reduced salivary flow rate. About 30% of the elderly (65 years and older experience xerostomia and hyposalivation. Structural and functional factors, or both may lead to salivary gland dysfunction.Study Selection: The EBM literature search was conducted by using the medical literature database MEDLINE via PubMed and OvidMedline search engines. Results were limited to English language articles (1965 to present including clinical trials (CT, randomized controlled trials (RCT, systematic reviews and review articles. Case control or cohort studies were included for the etiology.Results: Neuropathic etiology such as localized oral alteration of thermal sensations, saliva composition change (for example higher levels of K, Cl, Ca, IgA, amylase, calcium, PTH and cortisol, lower levels of estrogen and progesterone, smaller salivary gland size, and illnesses such as lichen planus, are risk indicators for unknown-origin xerostomia. The management is palliative and preventative. Management of symptoms includes drug administration (systemic secretogogues, saliva substitutes and bile secretion-stimulator, night guard, diet and habit modifications. Other managements may be indicated to treat adverse effects.Conclusion: Neuropathic etiology, saliva composition change, smaller salivary gland size, and illnesses such as oral lichen planus can be suggestive causes for unknown-origin xerostomia. However, longitudinal studies will be important to elucidate the causes of unknown-origin xerostomia.

Experimental evidence for the cardioprotective effects of red wine

OpenAIRE

Das, Samarjit; Santani, Dev D; Dhalla, Naranjan S

2007-01-01

Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary ...

Experimental Evidence of Momentum Transport Induced by an Up-Down Asymmetric Magnetic Equilibrium in Toroidal Plasmas

International Nuclear Information System (INIS)

Camenen, Y.; Peeters, A. G.; Casson, F. J.; Hornsby, W. A.; Snodin, A. P.; Szepesi, G.; Bortolon, A.; Duval, B. P.; Federspiel, L.; Karpushov, A. N.; Piras, F.; Sauter, O.

2010-01-01

The first experimental evidence of parallel momentum transport generated by the up-down asymmetry of a toroidal plasma is reported. The experiments, conducted in the Tokamak a Configuration Variable, were motivated by the recent theoretical discovery of ion-scale turbulent momentum transport induced by an up-down asymmetry in the magnetic equilibrium. The toroidal rotation gradient is observed to depend on the asymmetry in the outer part of the plasma leading to a variation of the central rotation by a factor of 1.5-2. The direction of the effect and its magnitude are in agreement with theoretical predictions for the eight possible combinations of plasma asymmetry, current, and magnetic field.

Characteristics of efficacy evidence supporting approval of supplemental indications for prescription drugs in United States, 2005-14: systematic review.

Science.gov (United States)

Wang, Bo; Kesselheim, Aaron S

2015-09-23

To characterize the types of comparators and endpoints used in efficacy trials for approvals of supplemental indications, compared with the data supporting these drugs' originally approved indications. Systematic review. Publicly accessible data on supplemental indications approved by the US Food and Drug Administration from 2005 to 2014. Types of comparators (active, placebo, historical, none) and endpoints (clinical outcomes, clinical scales, surrogate) in the efficacy trials for these drugs' supplemental and original indication approvals. The cohort included 295 supplemental indications. Thirty per cent (41/136) of supplemental approvals for new indications were supported by efficacy trials with active comparators, compared with 51% (47/93) of modified use approvals and 11% (7/65) of approvals expanding the patient population (Pindications, 30% (28/93) of modified indication approvals, and 22% (14/65) of expanded population approvals (P=0.29). Orphan drugs had supplemental approvals for 40 non-orphan indications, which were supported by similar proportions of trials using active comparators (28% (11/40) for non-orphan supplemental indications versus 24% (10/42) for original orphan indications; P=0.70) and clinical outcome endpoints (25% (10/40) versus 31% (13/42); P=0.55). Wide variations were seen in the evidence supporting approval of supplemental indications, with the fewest active comparators and clinical outcome endpoints used in trials leading to supplemental approvals that expanded the patient population. © Wang et al 2015.

Float level indicator

International Nuclear Information System (INIS)

Grishchuk, M.Kh.; Laptev, A.G.; Pashkov, V.A.

1980-01-01

Specially developed level indicator is suggested with differential to-transformer converter of the float motion, operating in line with a movable electronic block, intended for indicating the level of the dissociating nitrogen tetroxide liquid phase. On the basis of the indicator elements the device is realized to measure the time of calibrated volume fillino. in by liquid nitrogen tetroxide in steady state operation of the experimental bench-marks [ru

The experimental determination and evaluation of the spectral indices of the IPEN/MB-01 reactor for the IRPhE project

International Nuclear Information System (INIS)

Santos, Adimir dos; Fanaro, Leda C.C.B.; Jerez, Rogério

2013-01-01

Highlights: • A new experimental method for the spectral index measurements was developed. • The method eliminates the need of calculated correction factors for the case of 28 ρ. • The experimental results were approved for inclusion in the IRPhE handbook. • MCNP5 with ENDF/B-VII.0 described well the experimental data. - Abstract: New experimental results for the spectral indices of the IPEN/MB-01 reactor are presented in this work. The experimental approach considers a new technique for the 28 ρ case which does not require any sort of calculated correction factors. This aspect gave to the IPEN/MB-01 experiment an excellent quality and free of possible bias due to these calculated correction factors. The uncertainty analysis show, even considering the uncertainties of the geometric and material data of the facility, that the final uncertainties are small enough and well understood for a benchmark problem. The experiment was evaluated and included in the IRPhE handbook. The theory/experiment comparison reveals that there is considerable progress in the 238 U nuclear data for application in thermal reactors. The theory/experiment comparison employs the nuclear data libraries ENDF/B-VII.0, ENDF/B-VI.8, JEF3.1, and JENDL3.3 and reveals an excellent agreement for the spectral index 28 ρ * independently of the nuclear data library considered; aspect never found before in several other comparisons. The long term overprediction of the 238 U neutron epithermal capture appears to be eliminated with the improvements in the recent nuclear data libraries. The experimental performed at the IPEN/MB-01 reactor supports the changes in the 238 U nuclear data incorporated in ENDF/B-VII.0 as well as in the other libraries studied in this work. The theory/experiment comparison of 25 δ * and (C8/F) ept show that these spectral indices are in general slightly overpredicted, thus suggesting that the thermal fission cross section of 235 U might be a little bit underestimated

Towards the evidence of a purely spatial Einstein-Podolsky-Rosen paradox in images: measurement scheme and first experimental results

Science.gov (United States)

Devaux, F.; Mougin-Sisini, J.; Moreau, P. A.; Lantz, E.

2012-07-01

We propose a scheme to evidence the Einstein-Podolsky-Rosen (EPR) paradox for photons produced by spontaneous down conversion, from measurement of purely spatial correlations of photon positions both in the near- and in the far-field. Experimentally, quantum correlations have been measured in the far-field of parametric fluorescence created in a type II BBO crystal. Imaging is performed in the photon counting regime with an electron-multiplying CCD (EMCCD) camera.

Is the Internet making markets more efficient? The evidence according to price indicators in Spain

Directory of Open Access Journals (Sweden)

Ferran Sabate

2009-04-01

Full Text Available It has been theorized that low search costs associated with e-commerce imply greater levels of efficiency relative to the conventional retail channels. Multiple empirical studies confirm this hypothesis concerning price level, although the evidence is mixed relative to price dispersion. This article empirically compares the efficiency of the Internet with the conventional retail channel through 4 price indicators for the CD market. The results, based on 1,603 prices collected in Spain, are surprising. The conventional channel shows greater efficiency for both posted and final prices. These findings together with the coincident results of other reviewed studies would suggest key factors related to the development of e-commerce. Implications of the study and future considerations are discussed.

Plain packaging of cigarettes: do we have sufficient evidence?

Science.gov (United States)

Smith, Collin N; Kraemer, John D; Johnson, Andrea C; Mays, Darren

2015-01-01

Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. PMID:25897269

An experimental study on providing a scientific evidence for seven-time alcohol-steaming of Rhei Rhizoma when clinically used.

Science.gov (United States)

Sim, Yeomoon; Oh, Hyein; Oh, Dal-Seok; Kim, Namkwon; Gu, Pil Sung; Choi, Jin Gyu; Kim, Hyo Geun; Kang, Tong Ho; Oh, Myung Sook

2015-10-27

Rhei Rhizoma (RR) has been widely used as laxative and processed to alter its therapeutic actions or reduce its side effects. In this study, we evaluated experimentally the clinical application guideline that RR should be alcohol-steamed seven times before being used in elderly patients, as described in Dongeuibogam, the most famous book on Korean traditional medicine. Unprocessed RR (RR-U) was soaked in rice wine, steamed and then fully dried (RR-P1). The process was repeated four (RR-P4) or seven times (RR-P7). Reversed-phase high-performance liquid chromatography was used to determine the RR-U, RR-P1, RR-P4 and RR-P7 (RRs) constituents. To evaluate the effect of RRs on liver toxicity, human hepatoma cells (HepG2) were treated with RRs at 100 μg/mL for 4 h and then cell viabilities were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. To confirm the effects in vivo, 5-week-old male Sprague-Dawley rats were treated with RRs at 3 g/kg/day for 21 days. Body weight and serum biochemical parameters were measured and liver histology was assessed. The levels of sennosides decreased in processed RRs in an iteration-dependent manner, while the emodin level was unaffected. In HepG2 cells, cell viability was reduced with RR-U, while the toxicity decreased according to the number of processing cycles. The changes in body weight, relative liver weight and liver enzymes of RR-U-treated rats were reduced in processed RRs-treated rats. Histopathological analysis indicated swelling and cholestasis improved following seven times alcohol-steaming cycles. These results provide experimental evidence that RR-P7 almost completely reduces RR hepatotoxicity.

Experimental evidence for dual diffractive resonances in nucleon-nucleus scattering

International Nuclear Information System (INIS)

Ion, D.B.; Ion-Mihai, R.

1981-09-01

Experimental data on nucleon-nucleus scattering for laboratory momenta between 0.9:10 GeV/c are analysed in terms of the dual diffractive resonance (DDR) mechanism. The experimental data for all the nuclei are found to agree well with the predictions of the collective DDR states dominance. (authors)

Experimental Shock Transformation of Gypsum to Anhydrite: A New Low Pressure Regime Shock Indicator

Science.gov (United States)

Bell, Mary S.; Zolensky, Michael E.

2011-01-01

The shock behavior of gypsum is important in understanding the Cretaceous/Paleogene event and other terrestrial impacts that contain evaporite sediments in their targets (e.g., Mars Exploration Rover Spirit detected sulfate at Gusev crater, [1]). Most interest focuses on issues of devolatilization to quantify the production of SO2 to better understand its role in generating a temporary atmosphere and its effects on climate and biota [2,3]. Kondo and Ahrens [4] measured induced radiation emitted from single crystal gypsum shocked to 30 and 40 GPa. They observed greybody emission spectra corresponding to temperatures in the range of 3,000 to 4,000 K that are a factor of 2 to 10 times greater than calculated pressure-density energy equation of state temperatures (Hugoniot) and are high enough to melt gypsum. Chen et al. [5] reported results of shock experiments on anhydrite, gypsum, and mixtures of these phases with silica. Their observations indicated little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another report of shock experiments on calcite, anhydrite, and gypsum, Badjukov et al. [6] observed only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa but have not experimentally shocked gypsum in a step-wise manner to constrain possible incipient transformation effects. Schmitt and Hornemann [7] shock loaded anhydrite and quartz to a peak pressure of 60 GPa and report the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggested that recrystallization of anhydrite grains is the result of a solid-state transformation. They concluded that significant decomposition of anhydrite requires shock pressures higher than 60 GPa. Gupta et al. [8

Effectiveness of Student Learning during Experimental Work in Primary School.

Science.gov (United States)

Logar, Ana; Peklaj, Cirila; Ferk Savec, Vesna

2017-09-01

The aim of the research was to optimize the effectiveness of student learning based on experimental work in chemistry classes in Slovenian primary schools. To obtain evidence about how experimental work is implemented during regular chemistry classes, experimental work was videotaped during 19 units of chemistry lessons at 12 Slovenian primary schools from the pool of randomly selected schools. Altogether 332 eight-grade students were involved in the investigation, with an average age of 14.2 years. Students were videotaped during chemistry lessons, and their worksheets were collected afterward. The 12 chemistry teachers, who conducted lessons in these schools, were interviewed before the lessons; their teaching plans were also collected. The collected data was analyzed using qualitative methods. The results indicate that many teachers in Slovenian primary schools are not fully aware of the potential of experimental work integrated into chemistry lessons for the development of students' experimental competence. Further research of the value of different kinds of training to support teachers for the use of experimental work in chemistry teaching is needed.

Favorable results from the use of herbal and plant products in inflammatory bowel disease: evidence from experimental animal studies

Science.gov (United States)

Triantafillidis, John K.; Triantafyllidi, Aikaterini; Vagianos, Constantinos; Papalois, Apostolos

2016-01-01

The use of herbal therapy for inflammatory bowel disease is increasing worldwide. The aim of this study was to review the available literature on the efficacy of herbal therapy in experimental colitis. All relevant studies published in Medline and Embase up to June 2015 have been reviewed. The results of bowel histology and serum parameters have been recorded. A satisfactory number of published experimental studies, and a quite large one of both herbal and plant products tested in different studies have been reported. The results showed that in the majority of the studies, herbal therapy reduced the inflammatory activity of experimental colitis and diminished the levels of many inflammatory indices, including serum cytokines and indices of oxidative stress. The most promising plant and herbal products were tormentil extracts, wormwoodherb, Aloe vera, germinated barley foodstuff, curcumin, Boswellia serrata, Panax notoginseng, Ixeris dentata, green tea, Cordia dichotoma, Plantago lanceolata, Iridoidglycosides, and mastic gum. Herbal therapies exert their therapeutic benefit via various mechanisms, including immune regulation, anti-oxidant activity, inhibition of leukotriene B4 and nuclear factor-κB, and antiplatelet activity. Large, double-blind clinical studies assessing these natural substances should be urgently conducted. PMID:27366027

Plasmapheresis in immune hematology: review of clinical outcome data with respect to evidence-based medicine and clinical experience.

Science.gov (United States)

von Baeyer, Hans

2003-02-01

The objective of this paper is to assess the role of plasmapheresis in immune hematology by reviewing published clinical outcome data and narrative review articles. This information will be used to define evidence levels for appraisal of the efficacy and rank of plasmapheresis among other management options. This evidence-based strategy conforms to the concepts of the American Society of Hematology (ASH). as put forward in 1996 in the context of immune thrombocytopenia (ITP) treatment. The term 'experimental' is used to describe indications where the only scientific evidence of the efficacy of plasmapheresis consists of pathophysiological reasoning and empiric clinical findings. We reviewed the available literature on the use of plasmapheresis in autoimmune hemolytic anemia (AIHA), hemolytic disease of the newborn (HDN), autoimmune thrombocytopenic purpura (AITP), heparin-induced thrombocytopenia type II (HIT II), post-transfusion purpura (PTP), refractoriness to platelet transfusion (RPT), coagulation factor inhibitor (CFI) and catastrophic antiphospholipid syndrome (CAS). Plasmapheresis completes the spectrum of management options as it eliminates physically circulating free antibodies involved in the pathogenesis of these immune hematological syndromes. Because of the paucity of data, evidence levels had to be defined based on the findings of uncontrolled case series and the opinions of independent experts. In many cases, randomized clinical trials were not feasible because the syndromes are so rare. When defined as an 'experimental indication', plasmapheresis has a firm scientific basis, but larger scale clinical experience with the method is still lacking. In these cases, the detection and monitoring of symptomatic disease-related circulating free antibodies or immune complexes is a mandatory prerequisite for the use of plasmapheresis. The therapeutic benefit of plasmapheresis is substantiated by the level V of evidence of its efficacy in treatment of HDN, HIV

Experimental evidence for πK-atoms

International Nuclear Information System (INIS)

Amsler, C.

2009-01-01

We present evidence for the first observation of electromagnetically bound pion-kaon pairs (πK- atoms) with the DIRAC-II experiment at the CERN-PS. The mean life of πK-atoms is related to the s-wave πK-scattering lengths, a measurement of which is relevant to low energy QCD, in particular chiral perturbation theories including the s-quarks. The atoms are produced by a 24 GeV/c proton beam in a thin Pt-target and the dissociated pions and kaons analyzed in a two-arm magnetic spectrometer. The observed enhancement at low relative momentum corresponds to the production of 173± 54 πK-atoms. From these first data we derive a lower limit for the mean life of 0.8 fs at the 90 % confidence level. (author)

An experimental study on anti-electrostatic gauge rulers

International Nuclear Information System (INIS)

Lou, Renjie; Dai, Liping; Sun, Hong

2013-01-01

The process of oil filling will produce electrostatic phenomena which may cause fire accidents. There were no reports about research on the danger of static electricity generation in the process of gauging operation to date. This paper presents an experiment on charge transferring quantity of gauge rulers, and calculates the charge transferring quantity of an anti-electrostatic gauge ruler and a metal one, respectively. The results indicate that the charge transferring quantity can be more than 0.1 μC for a metal gauge ruler, while it is less than 0.1 μC for an antistatic gauge ruler. Therefore, this experimental research proves that using an anti-electrostatic gauge ruler is safer than using a metal one. This study also provides some theoretical and experimental evidence for making anti-electrostatic gauge rulers.

Experimental animal studies of radon and cigarette smoke

International Nuclear Information System (INIS)

Cross, F.T.; Dagle, G.E.; Gies, R.A.; Smith, L.G.; Buschbom, R.L.

1992-01-01

Cigarette-smoking is a dominant cause of lung cancer and confounds risk assessment of exposure to radon decay products. Evidence in humans on the interaction between cigarette-smoking and exposure to radon decay products, although limited, indicates a possible synergy. Experimental animal data, in addition to showing synergy, also show a decrease or no change in risk with added cigarette-smoke exposures. This article reviews previous animal data developed at Compagnie Generale des Matieres Nucleaires and Pacific Northwest Laboratory (PNL) on mixed exposures to radon and cigarette smoke, and highlights new initiation-promotion-initiation (IPI) studies at PNL that were designed within the framework of a two-mutation carcinogenesis model. Also presented are the PNL exposure system, experimental protocols, dosimetry, and biological data observed to date in IPI animals

An extended model of electrons: experimental evidence from high-resolution scanning tunneling microscopy

International Nuclear Information System (INIS)

Hofer, Werner A

2012-01-01

In a recent paper we introduced a model of extended electrons, which is fully compatible with quantum mechanics in the formulation of Schrödinger. However, it contradicts the current interpretation of electrons as point-particles. Here, we show by a statistical analysis of high-resolution scanning tunneling microscopy (STM) experiments, that the interpretation of electrons as point particles and, consequently, the interpretation of the density of electron charge as a statistical quantity will lead to a conflict with the Heisenberg uncertainty principle. Given the precision in these experiments we find that the uncertainty principle would be violated by close to two orders of magnitude, if this interpretation were correct. We are thus forced to conclude that the density of electron charge is a physically real, i.e. in principle precisely measurable quantity, as derived in a recent paper. Experimental evidence to the contrary, in particular high-energy scattering experiments, is briefly discussed. The finding is expected to have wide implications in condensed matter physics, chemistry, and biology, scientific disciplines which are based on the properties and interactions of electrons.

Babesia sp. BQ1 (Lintan): molecular evidence of experimental transmission to sheep by Haemaphysalis qinghaiensis and Haemaphysalis longicornis.

Science.gov (United States)

Guan, Guiquan; Moreau, Emmanuelle; Liu, Junlong; Hao, Xuefen; Ma, Miling; Luo, Jianxun; Chauvin, Alain; Yin, Hong

2010-06-01

Ovine babesiosis is an economically important disease induced by tick transmitted haemoparasites throughout the world. In China, several ovine Babesia strains have been isolated from field-collected ticks or sheep blood during the last two decades but little is known about the vector ticks and transmission pattern. Babesia sp. BQ1 (Lintan) is a Babesia strain infective for sheep and goats, isolated from blood of sheep experimentally infested with Haemaphysalis qinghaiensis collected in field. In the present study, we explored the experimental transmission of Babesia sp. BQ1 (Lintan) to sheep by H. qinghaiensis and Haemaphysalis longicornis. Based on the evidence from nested PCR, it suggested that H. qinghaiensis and H. longicornis are the potential vector ticks of Babesia sp. BQ1 (Lintan) and that larvae, nymphs and adults of both tick species were able to transmit Babesia sp. BQ1 (Lintan) to sheep. Parasites could be detected in the blood, by specific nested PCR, for one month post-infestation.

The impact of product information and trials on demand for smokeless tobacco and cigarettes: evidence from experimental auctions.

Science.gov (United States)

Rousu, Matthew C; O'Connor, Richard J; Thrasher, James F; June, Kristie M; Bansal-Travers, Maansi; Pitcavage, James

2014-03-01

Epidemiological and toxicological evidence suggests lower risk of smokeless tobacco (ST) products compared to cigarettes. Less is known, however, about consumer perceptions and use of novel forms of ST, including snus and dissolvable tobacco. In this study, we conducted in-person experimental auctions in Buffalo, NY, Columbia, SC, and Selinsgrove, PA with 571 smokers to test the impact of information and product trials on smokers' preferences. Auctions were conducted between November 2010-November 2011. We found no evidence of an impact of product trials on demand in our auctions. Anti-ST information increased demand for cigarettes when presented alone, but when presented with pro-ST information it decreased demand for cigarettes. It did not decrease demand for ST products. Anti-smoking information increased demand for ST products, but did not affect cigarette demand. These findings suggest that credible and effective communications about tobacco harm reduction should reinforce the negative effects of smoking. Copyright © 2013 Elsevier Inc. All rights reserved.

Experimental evidence of off-diagonal transport term and the discrepancy between energy/particle balance and perturbation analyses

International Nuclear Information System (INIS)

Nagashima, Keisuke; Fukuda, Takeshi

1991-12-01

Evidence of temperature gradient driven particle flux was observed from the sawtooth induced density propagation phenomenon in JT-60. This off-diagonal particle flux was confirmed using the numerical calculation of measured chord integrated electron density. It was shown that the discrepancies between thermal and particle diffusivities estimated from the perturbation method and energy/particle balance analysis can be explained by considering the flux equations with off-diagonal transport terms. These flux equations were compared with the E x B convective fluxes in an electro-static drift wave instability and it was found that the E x B fluxes are consistent with several experimental observations. (author)

Neural Correlates of Indicators of Sound Change in Cantonese: Evidence from Cortical and Subcortical Processes.

Science.gov (United States)

Maggu, Akshay R; Liu, Fang; Antoniou, Mark; Wong, Patrick C M

2016-01-01

Across time, languages undergo changes in phonetic, syntactic, and semantic dimensions. Social, cognitive, and cultural factors contribute to sound change, a phenomenon in which the phonetics of a language undergo changes over time. Individuals who misperceive and produce speech in a slightly divergent manner (called innovators ) contribute to variability in the society, eventually leading to sound change. However, the cause of variability in these individuals is still unknown. In this study, we examined whether such misperceptions are represented in neural processes of the auditory system. We investigated behavioral, subcortical (via FFR), and cortical (via P300) manifestations of sound change processing in Cantonese, a Chinese language in which several lexical tones are merging. Across the merging categories, we observed a similar gradation of speech perception abilities in both behavior and the brain (subcortical and cortical processes). Further, we also found that behavioral evidence of tone merging correlated with subjects' encoding at the subcortical and cortical levels. These findings indicate that tone-merger categories, that are indicators of sound change in Cantonese, are represented neurophysiologically with high fidelity. Using our results, we speculate that innovators encode speech in a slightly deviant neurophysiological manner, and thus produce speech divergently that eventually spreads across the community and contributes to sound change.

Bacteria are not too small for spatial sensing of chemical gradients: An experimental evidence

DEFF Research Database (Denmark)

Thar, Roland; Kühl, Michael

2003-01-01

By analyzing the chemotactic behavior of a recently described marine bacterial species, we provide experimental evidence that bacteria are not too small for sensing chemical gradients spatially. The bipolar flagellated vibrioid bacteria (typical size 2 × 6 µm) exhibit a unique motility pattern...... as they translate along as well as rotate around their short axis, i.e., the pathways of the cell poles describe a double helix. The natural habitat of the bacteria is characterized by steep oxygen gradients where they accumulate in a band at their preferred oxygen concentration of ˜2 µM. Single cells leaving...... the band toward the oxic region typically return to the band within 16 s following a U-shaped track. A detailed analysis of the tracks reveals that the cells must be able to sense the oxygen gradient perpendicular to their swimming direction. Thus, they can detect oxygen gradients along a distance of ˜5 µm...

Experimental evidence of the spatial coherence moiré and the filtering of classes of radiator pairs.

Science.gov (United States)

Castaneda, Roman; Usuga-Castaneda, Mario; Herrera-Ramírez, Jorge

2007-08-01

Evidence of the physical existence of the spatial coherence moiré is obtained by confronting numerical results with experimental results of spatially partial interference. Although it was performed for two particular cases, the results reveal a general behavior of the optical fields in any state of spatial coherence. Moreover, the study of the spatial coherence moiré deals with a new type of filtering, named filtering of classes of radiator pairs, which allows changing the power spectrum at the observation plane by modulating the complex degree of spatial coherence, without altering the power distribution at the aperture plane or introducing conventional spatial filters. This new procedure can optimize some technological applications of actual interest, as the beam shaping for instance.

Enjoyment: A Conceptual Exploration and Overview of Experimental Evidence in the Context of Games for Health.

Science.gov (United States)

Crutzen, Rik; van 't Riet, Jonathan; Short, Camille E

2016-02-01

Enjoyment is consistently noted as important for engaging audiences in games for health. However, as a term, enjoyment is often used interchangeably with a host of other terms, some of which overlap conceptually. This obscures what does and what does not constitute enjoyment, and in turn slows scientific progress by making the study of enjoyment and the synthesis of enjoyment-related research difficult. This article is aimed at improving our understanding of enjoyment by distinguishing enjoyment from other important constructs, such as fun and engagement, and by providing an overview of the experimental evidence on the determinants of enjoyment in videogames. Competence, narrative transportation, and relevance are identified as key factors related to enjoyment, and future studies examining these factors using games for health are recommended.

Bisphenol A and Reproductive Health: Update of Experimental and Human Evidence, 2007–2013

Science.gov (United States)

Peretz, Jackye; Vrooman, Lisa; Ricke, William A.; Hunt, Patricia A.; Ehrlich, Shelley; Hauser, Russ; Padmanabhan, Vasantha; Taylor, Hugh S.; Swan, Shanna H.; VandeVoort, Catherine A.

2014-01-01

health: update of experimental and human evidence, 2007–2013. Environ Health Perspect 122:775–786; http://dx.doi.org/10.1289/ehp.1307728 PMID:24896072

Effects of Ichthyophonus hoferi on condition indices and blood chemistry of experimentally infected rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Rand, T G; Cone, D K

1990-07-01

Body condition, hepatosomatic index and blood chemistry of Oncorhynchus mykiss experimentally infected with a tissue dwelling fish pathogenic fungus, Ichthyophonus hoferi, were monitored over a 6 wk period. This was to determine whether the infection constituted a stress manifest by changes in the hypothalamic-pituitary interrenal axis, and especially plasma cortisol levels. Infection caused anaemia and leucopenia but did not change the condition, hepatosomatic indices, or plasma chloride, cholesterol, cortisol, creatinine, glucose, osmolarity, potassium, total protein, sodium and T4. It is suggested that increased cortisol levels may not be a normal component of the stress response of fish to disease caused by invasive infectious agents.

Experimental and theoretical evidence for the chaotic dynamics of complex structures

International Nuclear Information System (INIS)

Agop, M; Dimitriu, D G; Poll, E; Niculescu, O; Radu, V

2013-01-01

This paper presents the experimental results on the formation, dynamics and evolution towards chaos of complex space charge structures that emerge in front of a positively biased electrode immersed in a quiescent plasma. In certain experimental conditions, we managed to obtain the so-called multiple double layers (MDLs) with non-concentric configuration. Our experiments show that the interactions between each MDL's constituent entities are held responsible for the complex dynamics and eventually for its transition to chaos through cascades of spatio-temporal sub-harmonic bifurcations. Further, we build a theoretical model based on the fractal approximation (scale relativity theory) in order to reproduce the experimental results (plasma self-structuring and scenario of evolution to chaos). Comparing the experimental results with the theoretical ones, we observe a good correlation between them. (paper)

Experimental evidence on formation of imminent and short-term hydrochemical precursors for earthquakes

International Nuclear Information System (INIS)

Du Jianguo; Amita, Kazuhiro; Ohsawa, Shinji; Zhang Youlian; Kang Chunli; Yamada, Makoto

2010-01-01

The formation of imminent hydrochemical precursors of earthquakes is investigated by the simulation for water-rock reaction in a brittle aquifer. Sixty-one soaking experiments were carried out with granodiorite and trachyandesite grains of different sizes and three chemically-distinct waters for 6 to 168 h. The experimental data demonstrate that water-rock reaction can result in both measurable increases and decreases of ion concentrations in short times and that the extents of hydrochemical variations are controlled by the grain size, dissolution and secondary mineral precipitation, as well as the chemistry of the rock and groundwater. The results indicate that water-rock reactions in brittle aquifers and aquitards may be an important genetic mechanism of hydrochemical seismic precursors when the aquifers and aquitards are fractured in response to tectonic stress.

An environmental scan of quality indicators in critical care.

Science.gov (United States)

Valiani, Sabira; Rigal, Romain; Stelfox, Henry T; Muscedere, John; Martin, Claudio M; Dodek, Peter; Lamontagne, François; Fowler, Robert; Gheshmy, Afshan; Cook, Deborah J; Forster, Alan J; Hébert, Paul C

2017-06-21

We performed a directed environmental scan to identify and categorize quality indicators unique to critical care that are reported by key stakeholder organizations. We convened a panel of experts ( n = 9) to identify key organizations that are focused on quality improvement or critical care, and reviewed their online publications and website content for quality indicators. We identified quality indicators specific to the care of critically ill adult patients and then categorized them according to the Donabedian and the Institute of Medicine frameworks. We also noted the organizations' rationale for selecting these indicators and their reported evidence base. From 28 targeted organizations, we identified 222 quality indicators, 127 of which were unique. Of the 127 indicators, 63 (32.5%) were safety indicators and 61 (31.4%) were effectiveness indicators. The rationale for selecting quality indicators was supported by consensus for 58 (26.1%) of the 222 indicators and by published research evidence for 45 (20.3%); for 119 indicators (53.6%), the rationale was not reported or the reader was referred to other organizations' reports. Of the 127 unique quality indicators, 27 (21.2%) were accompanied by a formal grading of evidence, whereas for 52 (40.9%), no reference to evidence was provided. There are many quality indicators related to critical care that are available in the public domain. However, owing to a paucity of rationale for selection, supporting evidence and results of implementation, it is not clear which indicators should be adopted for use. Copyright 2017, Joule Inc. or its licensors.

Competition and quality indicators in the health care sector: empirical evidence from the Dutch hospital sector.

Science.gov (United States)

Croes, R R; Krabbe-Alkemade, Y J F M; Mikkers, M C

2018-01-01

There is much debate about the effect of competition in healthcare and especially the effect of competition on the quality of healthcare, although empirical evidence on this subject is mixed. The Netherlands provides an interesting case in this debate. The Dutch system could be characterized as a system involving managed competition and mandatory healthcare insurance. Information about the quality of care provided by hospitals has been publicly available since 2008. In this paper, we evaluate the relationship between quality scores for three diagnosis groups and the market power indicators of hospitals. We estimate the impact of competition on quality in an environment of liberalized pricing. For this research, we used unique price and production data relating to three diagnosis groups (cataract, adenoid and tonsils, bladder tumor) produced by Dutch hospitals in the period 2008-2011. We also used the quality indicators relating to these diagnosis groups. We reveal a negative relationship between market share and quality score for two of the three diagnosis groups studied, meaning that hospitals in competitive markets have better quality scores than those in concentrated markets. We therefore conclude that more competition is associated with higher quality scores.

Experimental evidence of enhancement in the anticipation time by cascading

International Nuclear Information System (INIS)

Baraik, Abhijit; Singh, Harpartap; Parmananda, P.

2014-01-01

We have studied and verified experimentally the enhancement in the anticipation time by cascading Chua's circuits. The experiments have been carried out in a one dimensional array of Chua's circuits (2 to 8) coupled unidirectionally, such that each one acts as a master for the next one. By doing so, it has been observed that the anticipation time increases with an increase in the array size. Moreover, the numerical simulations of an array of eighty Chua's circuits verify the experimental observations.

Cash transfers, maternal depression and emotional well-being: Quasi-experimental evidence from India's Janani Suraksha Yojana programme.

Science.gov (United States)

Powell-Jackson, Timothy; Pereira, Shreya K; Dutt, Varun; Tougher, Sarah; Haldar, Kaveri; Kumar, Paresh

2016-08-01

Maternal depression is an important public health concern. We investigated whether a national-scale initiative that provides cash transfers to women giving birth in government health facilities, the Janani Suraksha Yojana (JSY), reduced maternal depression in India's largest state, Uttar Pradesh. Using primary data on 1695 women collected in early 2015, our quasi-experimental design exploited the fact that some women did not receive the JSY cash due to administrative problems in its disbursement - reasons that are unlikely to be correlated with determinants of maternal depression. We found that receipt of the cash was associated with an 8.5% reduction in the continuous measure of maternal depression and a 36% reduction in moderate depression. There was no evidence of an association with measures of emotional well-being, namely happiness and worry. The results suggest that the JSY had a clinically meaningful effect in reducing the burden of maternal depression, possibly by lessening the financial strain of delivery care. They contribute to the evidence that financial incentive schemes may have public health benefits beyond improving uptake of targeted health services. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

eHealth indicators

DEFF Research Database (Denmark)

HYPPÖNEN, Hannele; AMMENWERTH, Elske; Nøhr, Christian

2012-01-01

eHealth indicators are needed to measure defined aspects of national eHealth implementations. However, until now, eHealth indicators are ambiguous or unclear. Therefore, an expert workshop "Towards an International Minimum Dataset for Monitoring National Health Information System Implementations......" was organized. The objective was to develop ideas for a minimum eHealth indicator set. The proposed ideas for indicators were classified based on EUnetHTA and De-Lone & McClean, and classification was compared with health IT evaluation criteria classification by Ammenwerth & Keizer. Analysis of the workshop...... results emphasized the need for a common methodological framework for defining and classifying eHealth indicators. It also showed the importance of setting the indicators into context. The results will benefit policy makers, developers and researchers in pursuit of provision and use of evidence...

The Modulation of Pain by Circadian and Sleep-Dependent Processes: A Review of the Experimental Evidence

DEFF Research Database (Denmark)

Hagenauer, Megan; Crodelle, Jennifer; Piltz, Sofia Helena

2017-01-01

conditions, pain sensitivity varies across the 24 h day, with highest sensitivity occurring during the evening in humans. Pain sensitivity is also modulated by sleep behavior, with pain sensitivity increasing in response to the build-up of homeostatic sleep pressure following sleep deprivation or sleep...... of physiologically meaningful stimulation levels. Following this normalization, we find that the estimated impact of the daily rhythm and of sleep deprivation on experimental pain measurements is surprisingly consistent across different pain modalities. We also review evidence documenting the impact of circadian...... rhythms and sleep deprivation on the neural circuitry in the spinal cord underlying pain sensation. The characterization of sleep-dependent and circadian influences on pain sensitivity in this review paper is used to develop and constrain the mathematical models introduced in the two companion articles....

Experimental evidence that wildflower strips increase pollinator visits to crops.

Science.gov (United States)

Feltham, Hannah; Park, Kirsty; Minderman, Jeroen; Goulson, Dave

2015-08-01

Wild bees provide a free and potentially diverse ecosystem service to farmers growing pollination-dependent crops. While many crops benefit from insect pollination, soft fruit crops, including strawberries are highly dependent on this ecosystem service to produce viable fruit. However, as a result of intensive farming practices and declining pollinator populations, farmers are increasingly turning to commercially reared bees to ensure that crops are adequately pollinated throughout the season. Wildflower strips are a commonly used measure aimed at the conservation of wild pollinators. It has been suggested that commercial crops may also benefit from the presence of noncrop flowers; however, the efficacy and economic benefits of sowing flower strips for crops remain relatively unstudied. In a study system that utilizes both wild and commercial pollinators, we test whether wildflower strips increase the number of visits to adjacent commercial strawberry crops by pollinating insects. We quantified this by experimentally sowing wildflower strips approximately 20 meters away from the crop and recording the number of pollinator visits to crops with, and without, flower strips. Between June and August 2013, we walked 292 crop transects at six farms in Scotland, recording a total of 2826 pollinators. On average, the frequency of pollinator visits was 25% higher for crops with adjacent flower strips compared to those without, with a combination of wild and commercial bumblebees (Bombus spp.) accounting for 67% of all pollinators observed. This effect was independent of other confounding effects, such as the number of flowers on the crop, date, and temperature. Synthesis and applications. This study provides evidence that soft fruit farmers can increase the number of pollinators that visit their crops by sowing inexpensive flower seed mixes nearby. By investing in this management option, farmers have the potential to increase and sustain pollinator populations over time.

Experimental evidence of enhancement in the anticipation time by cascading

Energy Technology Data Exchange (ETDEWEB)

Baraik, Abhijit; Singh, Harpartap; Parmananda, P.

2014-04-01

We have studied and verified experimentally the enhancement in the anticipation time by cascading Chua's circuits. The experiments have been carried out in a one dimensional array of Chua's circuits (2 to 8) coupled unidirectionally, such that each one acts as a master for the next one. By doing so, it has been observed that the anticipation time increases with an increase in the array size. Moreover, the numerical simulations of an array of eighty Chua's circuits verify the experimental observations.

Nanostructured diamine-fullerene derivatives: computational density functional theory study and experimental evidence for their formation via gas-phase functionalization.

Science.gov (United States)

Contreras-Torres, Flavio F; Basiuk, Elena V; Basiuk, Vladimir A; Meza-Laguna, Víctor; Gromovoy, Taras Yu

2012-02-16

Nanostructure derivatives of fullerene C(60) are used in emerging applications of composite matrices, including protective and decorative coating, superadsorbent material, thin films, and lightweight high-strength fiber-reinforced materials, etc. In this study, quantum chemical calculations and experimental studies were performed to analyze the derivatives of diamine-fullerene prepared by the gas-phase solvent-free functionalization technique. In particular, the aliphatic 1,8-diamino-octane and the aromatic 1,5-diaminonaphthalene, which are diamines volatile in vacuum, were studied. We addressed two alternative mechanisms of the amination reaction via polyaddition and cross-linking of C(60) with diamines, using the pure GGA BLYP, PW91, and PBE functionals; further validation calculations were performed using the semiempirical dispersion GGA B97-D functional which contains parameters that have been specially adjusted by a more realistic view on dispersion contributions. In addition, we looked for experimental evidence for the covalent functionalization by using laser desorption/ionization time-of-flight mass spectrometry, thermogravimetric analysis, and atomic force microscopy.

Enhancing the gene-environment interaction framework through a quasi-experimental research design: evidence from differential responses to September 11.

Science.gov (United States)

Fletcher, Jason M

2014-01-01

This article uses a gene-environment interaction framework to examine the differential responses to an objective external stressor based on genetic variation in the production of depressive symptoms. This article advances the literature by utilizing a quasi-experimental environmental exposure design, as well as a regression discontinuity design, to control for seasonal trends, which limit the potential for gene-environment correlation and allow stronger causal claims. Replications are attempted for two prominent genes (5-HTT and MAOA), and three additional genes are explored (DRD2, DRD4, and DAT1). This article provides evidence of a main effect of 9/11 on reports of feelings of sadness and fails to replicate a common finding of interaction using 5-HTT but does show support for interaction with MAOA in men. It also provides new evidence that variation in the DRD4 gene modifies an individual's response to the exposure, with individuals with no 7-repeats found to have a muted response.

Is there any evidence that cerebral protection is beneficial? Experimental data.

Science.gov (United States)

Macdonald, S

2006-04-01

This article presents the available experimental data from the world literature on the use of cerebral protection devices during carotid artery stenting (CAS). Clinical studies relying on surrogate markers of cerebral embolisation in place of neurological event rate as primary outcome measures are evaluated alongside bench-top and animal studies. These surrogate markers include evaluations of outcomes using procedural transcranial Doppler (TCD) and diffusion-weighted magnetic resonance imaging of brain (DWI). Pathological analyses of debris retrieved from in-vivo analyses of protection devices are also included in this review because although the focus of these studies was primarily clinical, the laboratory data will be preferentially presented and it provides interesting insights. It can be shown that each of the three philosophies of cerebral protection, namely flow arrest (proximal or distal), flow reversal and distal filtration is capable of the entrapment of sizeable debris that would logically threaten devastating stroke if it embolized to the brain. Whilst balloon occlusion significantly reduces the procedural microembolic load (particles less than 60 mm) and flow reversal may be the first means to entirely eliminate it, filters may be associated with increased microembolization. This has been described by some workers as controlled embolization. Certainly, particles smaller than the pore size of currently available filters (60-140 mm) will readily evade capture due to filter periflow and through-flow. There is evidence to suggest that tens of thousands of particles of this size may be released during CAS and there is some evidence that this may be associated with more new white lesions on DWI of brain. The clinical consequences of this controlled embolization however, remain unclear and sophisticated neuropsychometric test batteries may need to be applied at later time points to detect subtle injury that may be compounded by a late inflammatory response

Physics of human cooperation: experimental evidence and theoretical models

Science.gov (United States)

Sánchez, Angel

2018-02-01

In recent years, many physicists have used evolutionary game theory combined with a complex systems perspective in an attempt to understand social phenomena and challenges. Prominent among such phenomena is the issue of the emergence and sustainability of cooperation in a networked world of selfish or self-focused individuals. The vast majority of research done by physicists on these questions is theoretical, and is almost always posed in terms of agent-based models. Unfortunately, more often than not such models ignore a number of facts that are well established experimentally, and are thus rendered irrelevant to actual social applications. I here summarize some of the facts that any realistic model should incorporate and take into account, discuss important aspects underlying the relation between theory and experiments, and discuss future directions for research based on the available experimental knowledge.

Socioeconomic status indicators and common mental disorders: Evidence from a study of prenatal depression in Pakistan

Directory of Open Access Journals (Sweden)

Joanna Maselko

2018-04-01

Full Text Available There is growing interest in the relationship between socioeconomic status (SES, poverty, and mental health in low and middle-income countries (LMIC. However, it is not clear whether a gradient approach focused on a wider SES distribution or a binary poverty approach is more salient for mental health in LMIC. Yet this distinction has implications for interventions aimed at improving population health. We contribute to the literature by examining how multiple indicators of socioeconomic status, including gradient SES and binary poverty indicators, contribute to prenatal depression symptoms in a LMIC context. Prenatal depression is an important public health concern with negative sequela for the mother and her children. We use data on assets, education, food insecurity, debt, and depression symptoms from a sample of 1154 pregnant women residing in rural Pakistan. Women who screened positive for depression participated in a cluster randomized controlled trial of a perinatal depression intervention; all women were interviewed October 2015-February 2016, prior to the start of the intervention. Cluster-specific sampling weights were used to approximate a random sample of pregnant women in the area. Findings indicate that fewer assets, experiencing food insecurity, and having household debt are independently associated with worse depression symptoms. The association with assets is linear with no evidence of a threshold effect, supporting the idea of a gradient in the association between levels of SES and depression symptoms. A gradient was also initially observed with woman’s educational attainment, but this association was attenuated once other SES variables were included in the model. Together, the asset, food insecurity, and debt indicators explain 14% of the variance in depression symptoms, more than has been reported in high income country studies. These findings support the use of multiple SES indicators to better elucidate the complex

Experimental evidence concerning the significant information depth of electron backscatter diffraction (EBSD)

Energy Technology Data Exchange (ETDEWEB)

Wisniewski, Wolfgang, E-mail: wolfgang.w@uni-jena.de [Otto-Schott-Institut, Jena University, Fraunhoferstr. 6, 07743 Jena (Germany); Saager, Stefan [Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Winterbergstraße 28, 01277 Dresden (Germany); Böbenroth, Andrea [Fraunhofer Institute for the Microstructure of Materials and Systems IMWS, Walter-Huelse-Straße 1, 06120 Halle (Saale) (Germany); Rüssel, Christian [Otto-Schott-Institut, Jena University, Fraunhoferstr. 6, 07743 Jena (Germany)

2017-02-15

Experiments concerning the information depth of electron backscatter diffraction (EBSD) are performed on samples featuring an amorphous wedge on a crystalline substrate and a crystalline wedge on an amorphous substrate. The effects of the acceleration voltage and exemplary software settings on the ability to measure through an amorphous layer are presented. Changes in the EBSD-signal could be detected through a ≈142 nm thick layer of amorphous Si while orientation measurements could be performed through a ≈116 nm thick layer when using a voltage of 30 kV. The complexity of the information depth significant to a given EBSD-pattern and the multiple parameters influencing it are discussed. It is suggested that a “core information depth” is significant to high quality patterns while a larger “maximum information depth” becomes relevant when the pattern quality decreases or the sample is inhomogeneous within the information volume, i.e. in the form of partially crystalline materials or crystal layers in the nm scale. - Highlights: • Experimental evidence of the significant information depth of EBSD is presented. • Effects of the voltage and exemplary software settings are discussed. • Dependence of the significant information depth on the pattern quality is proposed. • The information depth may reach up to 142 nm in Si when using a voltage of 30 kV. • The information depth depends on the available technology.

Optimal decision making on the basis of evidence represented in spike trains.

Science.gov (United States)

Zhang, Jiaxiang; Bogacz, Rafal

2010-05-01

Experimental data indicate that perceptual decision making involves integration of sensory evidence in certain cortical areas. Theoretical studies have proposed that the computation in neural decision circuits approximates statistically optimal decision procedures (e.g., sequential probability ratio test) that maximize the reward rate in sequential choice tasks. However, these previous studies assumed that the sensory evidence was represented by continuous values from gaussian distributions with the same variance across alternatives. In this article, we make a more realistic assumption that sensory evidence is represented in spike trains described by the Poisson processes, which naturally satisfy the mean-variance relationship observed in sensory neurons. We show that for such a representation, the neural circuits involving cortical integrators and basal ganglia can approximate the optimal decision procedures for two and multiple alternative choice tasks.

Violation of specific indicators pigment and lipid metabolism in experimental pneumonia in an immobilization stress and correction of corvitin

OpenAIRE

Ferenc, N. M.

2015-01-01

Ferenc N. M. Violation of specific indicators pigment and lipid metabolism in experimental pneumonia in an immobilization stress and correction of corvitin. Journal of Education, Health and Sport. 2015;5(9):709-713. ISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.32430 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%289%29%3A709-713 https://pbn.nauka.gov.pl/works/658656 Formerly Journal of Health Sciences. ISSN 1429-9623 / 2300-665X. Archives 2011–2014 http://journ...

Pharmacology of human experimental anxiety

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F.G. Graeff

2003-04-01

Full Text Available This review covers the effect of drugs affecting anxiety using four psychological procedures for inducing experimental anxiety applied to healthy volunteers and patients with anxiety disorders. The first is aversive conditioning of the skin conductance responses to tones. The second is simulated public speaking, which consists of speaking in front of a video camera, with anxiety being measured with psychometric scales. The third is the Stroop Color-Word test, in which words naming colors are painted in the same or in a different shade, the incongruence generating a cognitive conflict. The last test is a human version of a thoroughly studied animal model of anxiety, fear-potentiated startle, in which the eye-blink reflex to a loud noise is recorded. The evidence reviewed led to the conclusion that the aversive conditioning and potentiated startle tests are based on classical conditioning of anticipatory anxiety. Their sensitivity to benzodiazepine anxiolytics suggests that these models generate an emotional state related to generalized anxiety disorder. On the other hand, the increase in anxiety determined by simulated public speaking is resistant to benzodiazepines and sensitive to drugs affecting serotonergic neurotransmission. This pharmacological profile, together with epidemiological evidence indicating its widespread prevalence, suggests that the emotional state generated by public speaking represents a species-specific response that may be related to social phobia and panic disorder. Because of scant pharmacological data, the status of the Stroop Color-Word test remains uncertain. In spite of ethical and economic constraints, human experimental anxiety constitutes a valuable tool for the study of the pathophysiology of anxiety disorders.

Development of an experimental method for the determination of the dose equivalent indices for low - and medium energy X- and gamma rays

International Nuclear Information System (INIS)

Silva Estrada, J.J. da.

1980-01-01

An experimental method was developed to measure Dose Equivalent Indices for low and medium energy X-rays. A sphere was constructed to simulate the human body in accordance with ICRU Report 19 but using plexiglass instead of tissue equivalent material of density 1 g.cm -3 . Experimentally it was demonstrated that for the purpose of applied radiation protection both materials are equivalent in spite of a 18% higher density of plexiglass. CaF 2 :Mn and LiF:Mg might be utilized to determine the absorbed dose distribution within the sphere. Measurements indicate that the effective energy can be determined with an accuracy better than 15% for the energy range under consideration. Depth dose curves measured with ionization chamber compared with those of LiF:Mg showed an agreement better than 12% and in the case of CaF 2 :Mn better than 11% for all irradiation conditions used. Conversion factors in units rad R -1 measured with TLD and compared with those obtained from the literature based upon Monte Carlo calculation showed an agreement better than 23% for CaF 2 :Mn and 19% for LiF:Mg. It is concluded from these experiments that the system plexiglass sphere-TLD dosimeters might be used to measure Dose Equivalent Indices for low and medium energy photons. (Author) [pt

Review: fetal programming of polycystic ovary syndrome by androgen excess: evidence from experimental, clinical, and genetic association studies.

Science.gov (United States)

Xita, Nectaria; Tsatsoulis, Agathocles

2006-05-01

Polycystic ovary syndrome (PCOS) is a common endocrine disorder of premenopausal women, characterized by hyperandrogenism, polycystic ovaries, and chronic anovulation along with insulin resistance and abdominal obesity as frequent metabolic traits. Although PCOS manifests clinically during adolescence, emerging data suggest that the natural history of PCOS may originate in intrauterine life. Evidence from experimental, clinical, and genetic research supporting the hypothesis for the fetal origins of PCOS has been analyzed. Female primates, exposed in utero to androgen excess, exhibit the phenotypic features of PCOS during adult life. Clinical observations also support a potential fetal origin of PCOS. Women with fetal androgen excess disorders, including congenital 21-hydroxylase deficiency and congenital adrenal virilizing tumors, develop features characteristic of PCOS during adulthood despite the normalization of androgen excess after birth. The potential mechanisms of fetal androgen excess leading to a PCOS phenotype in humans are not clearly understood. However, maternal and/or fetal hyperandrogenism can provide a plausible mechanism for fetal programing of PCOS, and this, in part, may be genetically determined. Thus, genetic association studies have indicated that common polymorphic variants of genes determining androgen activity or genes that influence the availability of androgens to target tissues are associated with PCOS and increased androgen levels. These genomic variants may provide the genetic link to prenatal androgenization in human PCOS. Prenatal androgenization of the female fetus induced by genetic and environmental factors, or the interaction of both, may program differentiating target tissues toward the development of PCOS phenotype in adult life.

Fission track dating of volcanic glass: experimental evidence for the validity of the Size-Correction Method

International Nuclear Information System (INIS)

Bernardes, C.; Hadler Neto, J.C.; Lattes, C.M.G.; Araya, A.M.O.; Bigazzi, G.; Cesar, M.F.

1986-01-01

Two techniques may be employed for correcting thermally lowered fission track ages on glass material: the so called 'size-correcting method' and 'Plateau method'. Several results from fission track dating on obsidian were analysed in order to compare the model rising size-correction method with experimental evidences. The results from this work can be summarized as follows: 1) The assumption that mean size of spontaneous and induced etched tracks are equal on samples unaffected by partial fading is supported by experimental results. If reactor effects such as an enhancing of the etching rate in the irradiated fraction due to the radiation damage and/or to the fact that induced fission releases a quantity of energy slightly greater than spontaneous one exist, their influence on size-correction method is very small. 2) The above two correction techniques produce concordant results. 3) Several samples from the same obsidian, affected by 'instantaneous' as well as 'continuous' natural fading to different degrees were analysed: the curve showing decreasing of spontaneous track mean-size vs. fraction of spontaneous tracks lost by fading is in close agreement with the correction curve constructed for the same obsidian by imparting artificial thermal treatements on induced tracks. By the above points one can conclude that the assumptions on which size-correction method is based are well supported, at least in first approximation. (Author) [pt

Practice and application of problem-based learning in evidence-based medicine teaching

Directory of Open Access Journals (Sweden)

Tian-Ao Li

2014-10-01

Full Text Available AIM:To investigate the effect of problem-based learning(PBLused in the teaching of medical students' evidence-based medicine(EBM.METHODS: Five classes(total 147 studentswere randomly selected as experimental(PBLgroup, at the same time, another 5 classes(total 149 studentswere also randomly selected as control group, using traditional teaching method(lecture-based learning, LBLin 2010 grade. The final examination scores of the experimental group were compared with control at the end of term. In addition, all students were interviewed using self-administered questionnaire to obtain their evaluation for PBL practice. SPSS13.0 software was used for statistical analysis.RESULTS: The homogeneity test in baseline survey showed that the basic characteristics between the two groups of students were no significant differences, and were comparable(P>0.05. Final exam results showed that in addition to the scores of the EBM basic knowledge indicated no significant difference between two groups of students(P>0.05, for the 5 steps of EBM procedure, namely, asking questions, finding the best evidence, evaluating the evidence, using and practicing the evidence, re-evaluating the evidence, and the total scores between the two groups, there were significant statistically differences(PP>0.05in aspects of better understanding classroom knowledge, improving language expression ability, and writing skill exercises. And other residual items had a significant difference(PPCONCLUSION:PBL teaching mode can effectively improve teaching effectiveness and the quality of EBM teaching, so the this teaching mode is worth further popularizing.

Experimental type 2 diabetes mellitus and acetaminophen toxic lesions: glutathione system indices changes

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Olga Furka

2017-11-01

Full Text Available Background. The goal of the research was to study the effect of acetaminophen on major glutathione part of antioxidant system indices in liver homogenate of rats with type 2 diabetes mellitus in time dynamics. Materials and methods. We conducted two series of experiments. In the first series toxic lesion was caused by a single intragastric administration of acetaminophen suspension in 2 % starch solution to animals in a dose of 1250 mg/kg (1/2 LD50. In the second series  the suspension of acetaminophen in 2 % starch solution in a dose of 55 mg/kg was given, which corresponds to the highest therapeutic dose during 7 days. Non-genetic form of experimental type 2 diabetes mellitus was modeled by Islam S., Choi H. method (2007. Activity of glutathione peroxidase (GPx and glutathione reductase (GR, and contents of reduced glutathione (GSH were determined in liver homogenate. Results. The obtained results have shown that GR and GPx activity actively decreased after acetaminophen administration in higher therapeutic doses to rats with type 2 DM. However, the changes were less pronounced than in rats with type 2 DM and acute acetaminophen toxic lesions. Conclusion. Results of the research have shown that acetaminophen administration to rats with type 2 DM causes a significant violation of compensatory mechanisms, especially of the enzyme and nonenzyme parts of antioxidant system.

Experimental evidence for the cardioprotective effects of red wine.

Science.gov (United States)

Das, Samarjit; Santani, Dev D; Dhalla, Naranjan S

2007-01-01

Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary vasodilation in addition to attenuating oxidative stress by its action on the central nervous system. The antioxidant components of red wine may provide cardioprotection by their ability to reduce oxidative stress in the heart under different pathological conditions. Mild-to-moderate red wine consumption improves cardiac function in the ischemic myocardium through the protection of endothelial function, the expression of several cardioprotective oxidative stress-inducible proteins, as well as the activation of adenosine receptors and nitrous oxide synthase mechanisms.

Experimental evidence for the cardioprotective effects of red wine

Science.gov (United States)

Das, Samarjit; Santani, Dev D; Dhalla, Naranjan S

2007-01-01

Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary vasodilation in addition to attenuating oxidative stress by its action on the central nervous system. The antioxidant components of red wine may provide cardioprotection by their ability to reduce oxidative stress in the heart under different pathological conditions. Mild-to-moderate red wine consumption improves cardiac function in the ischemic myocardium through the protection of endothelial function, the expression of several cardioprotective oxidative stress-inducible proteins, as well as the activation of adenosine receptors and nitrous oxide synthase mechanisms. PMID:18650973

Is Deqi an Indicator of Clinical Efficacy of Acupuncture? A Systematic Review

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Shuo Zhang

2013-01-01

Full Text Available Objective. Despite the systematic literature review of the current evidence, we aim to answer the question “ is Deqi an indicator of clinical effects in acupuncture treatment?” Methods. We systematically searched CNKI, VIP, Wanfang Data, PubMed, Embase, and the CENTRAL for three types of study: (1 empirical research probing into the role of Deqi in acupuncture; (2 mechanism studies examining the effect of Deqi on physiological parameters in animal models and human subjects; (3 clinical studies that compared the outcome of acupuncture with Deqi with that of acupuncture without Deqi. Two reviewers independently extracted data, undertook qualitative or quantitative analysis, and summarized findings. Results. The ancient Chinese acupuncturists valued the role of Deqi as a diagnostic tool, a prognosis predictor, and a necessary part of the therapeutic procedure. Findings from modern experimental research provided preliminary evidence for the physiological mechanism that produced Deqi. Few clinical studies generated conflicting evidence of the comparative effectiveness of acupuncture with Deqi versus acupuncture without Deqi for a variety of conditions. Conclusion. The current evidence base is not solid enough to draw any conclusion regarding the predicative value of natural Deqi for clinical efficacy or the therapeutic value of manipulation-facilitated Deqi.

Experimental induced avian E. coli salpingitis

DEFF Research Database (Denmark)

Olsen, Rikke Heidemann; Thøfner, Ida; Pors, Susanne Elisabeth

2016-01-01

Several types of Escherichia coli have been associated with extra-intestinal infections in poultry, however, they may vary significantly in their virulence potential. The aim of the present study was to investigate the virulence of five strains of E. coli obtained from different disease......) had a distinct ability to cause disease. Results of the study shows major differences in virulence of different strains of E. coli in ascending infections; however, there was no indication of tissue-specific adaptation, since strains obtained from lesions unrelated to the reproductive system were...... fully capable of causing experimental infection. In conclusion, the study provides evidence for the clinical outcome of infection with E. coli in poultry is largely influenced by the specific strain as well as individual host factors....

Pediatric obstructive sleep apnea and the critical role of oral-facial growth: evidences.

Science.gov (United States)

Huang, Yu-Shu; Guilleminault, Christian

2012-01-01

Review of evidence in support of an oral-facial growth impairment in the development of pediatric sleep apnea in non-obese children. Review of experimental data from infant monkeys with experimentally induced nasal resistance. Review of early historical data in the orthodontic literature indicating the abnormal oral-facial development associated with mouth breathing and nasal resistance. Review of the progressive demonstration of sleep-disordered-breathing (SDB) in children who underwent incomplete treatment of OSA with adenotonsillectomy, and demonstration of abnormal oral-facial anatomy that must often be treated in order for the resolution of OSA. Review of data of long-term recurrence of OSA and indication of oral-facial myofunctional dysfunction in association with the recurrence of OSA. Presentation of prospective data on premature infants and SDB-treated children, supporting the concept of oral-facial hypotonia. Presentation of evidence supporting hypotonia as a primary element in the development of oral-facial anatomic abnormalities leading to abnormal breathing during sleep. Continuous interaction between oral-facial muscle tone, maxillary-mandibular growth and development of SDB. Role of myofunctional reeducation with orthodontics and elimination of upper airway soft tissue in the treatment of non-obese SDB children. Pediatric OSA in non-obese children is a disorder of oral-facial growth.

Experimental evidence of structural transition at the crystal-amorphous interphase boundary between Al and Al2O3

International Nuclear Information System (INIS)

Yang, Z.Q.; He, L.L.; Zhao, S.J.; Ye, H.Q.

2002-01-01

High-resolution transmission electron microscopy observations on the structure of the interphase boundary between crystalline Al and amorphous Al 2 O 3 coating reveal that an interfacial melting transition of Al occurs at 833 K, which is distinctly lower than the bulk melting point of Al. The crystalline lattice planes of Al near the interface bend or small segments of crystalline Al deviated from the matrix Al grains are formed. Stand-off dislocations formed at the interphase boundary are also observed. The amorphous Al 2 O 3 coating plays an important role in retaining the evidence for structural transition at high temperature to room temperature, which makes it possible to make experimental observations. (author)

Peroxisome Proliferator-Activated Receptors as Mediators of Phthalate-Induced Effects in the Male and Female Reproductive Tract: Epidemiological and Experimental Evidence

Directory of Open Access Journals (Sweden)

Giuseppe Latini

2008-01-01

Full Text Available There is growing evidence that male as well as female reproductive function has been declining in human and wildlife populations over the last 40 years. Several factors such as lifestyle or environmental xenobiotics other than genetic factors may play a role in determining adverse effects on reproductive health. Among the environmental xenobiotics phthalates, a family of man-made pollutants are suspected to interfere with the function of the endocrine system and therefore to be endocrine disruptors. The definition of endocrine disruption is today extended to broader endocrine regulations, and includes activation of metabolic sensors, such as the peroxisome proliferator-activated receptors (PPARs. Toxicological studies have shown that phthalates can activate a subset of PPARs. Here, we analyze the epidemiological and experimental evidence linking phthalate exposure to both PPAR activation and adverse effects on male and female reproductive health.

Leading indicators of crisis incidence: evidence from developed countries

Czech Academy of Sciences Publication Activity Database

Babecký, J.; Havránek, T.; Matějů, Jakub; Rusnák, M.; Šmídková, K.; Vašíček, B.

2013-01-01

Roč. 35, June (2013), s. 1-19 ISSN 0261-5606 R&D Projects: GA MŠk(CZ) SVV 267801/2013 Institutional support: PRVOUK-P23 Keywords : early warning indicators * Bayesian model averaging * economic crises Subject RIV: AH - Economics Impact factor: 1.090, year: 2013

Quasi-experimental study designs series-paper 11: supporting the production and use of health systems research syntheses that draw on quasi-experimental study designs.

Science.gov (United States)

Lavis, John N; Bärnighausen, Till; El-Jardali, Fadi

2017-09-01

To describe the infrastructure available to support the production of policy-relevant health systems research syntheses, particularly those incorporating quasi-experimental evidence, and the tools available to support the use of these syntheses. Literature review. The general challenges associated with the available infrastructure include their sporadic nature or limited coverage of issues and countries, whereas the specific ones related to policy-relevant syntheses of quasi-experimental evidence include the lack of mechanism to register synthesis titles and scoping review protocols, the limited number of groups preparing user-friendly summaries, and the difficulty of finding quasi-experimental studies for inclusion in rapid syntheses and research syntheses more generally. Although some new tools have emerged in recent years, such as guidance workbooks and citizen briefs and panels, challenges related to using available tools to support the use of policy-relevant syntheses of quasi-experimental evidence arise from such studies potentially being harder for policymakers and stakeholders to commission and understand. Policymakers, stakeholders, and researchers need to expand the coverage and institutionalize the use of the available infrastructure and tools to support the use of health system research syntheses containing quasi-experimental evidence. Copyright © 2017 Elsevier Inc. All rights reserved.

Educational evidence based interventions for adults with autism spectrum disorders: experimental evidence

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Saverio Fontani

2017-01-01

Full Text Available The educational interventions for adults with autism spectrum disorders are a relatively unexplored topic, in the face of numerous studies on the educational intervention models for the child population. In this paper the results of major studies and meta-analysis on the topic are presented and their implications for educational intervention are discussed.Interventi educativi evidence based per adulti con disturbi dello spettro autistico: evidenze sperimentaliGli interventi educativi per adulti con Disturbi dello Spettro Autistico rappresentano un’area relativamente poco esplorata, a fronte di numerosi studi dedicati ai modelli di intervento educativo rivolti alla popolazione infantile. In questo articolo sono presentati i risultati dei principali studi e delle meta-analisi sul tema e vengono discusse le loro implicazioni per l’intervento educativo.

The fishermen were right: experimental evidence for tributary refuge hypothesis during floods.

Science.gov (United States)

Koizumi, Itsuro; Kanazawa, Yukiyo; Tanaka, Yuuki

2013-05-01

Fishermen often anecdotally report an unexpected increase of fish caught in small tributary streams during floods, presumably due to refuge-seeking behavior from the main stem. From a population perspective, this implies the significance of refuge habitats and connectivity for population viability against natural disturbances. Despite the plausibility, however, surprisingly few studies have examined the tributary refuge hypothesis, mainly due to the difficulty in field survey during floods. Here, we made use of a large-scale controlled flood to assess whether fishes move into tributaries during flooding in the main stem. A planned water release from the Satsunai River Dam located on Hokkaido Island in Japan rapidly increased the main stem discharge by more than 20-fold. Before, during, and after flooding censuses in four tributaries provided evidence of the refuge-seeking behavior of fishes from the main stem. For example, more than 10 Dolly Varden char, a salmonid fish, were caught in a tributary during the flood, even though almost no individuals were captured before or after the flood. The fish responded immediately to the flooding, suggesting the need for studies during disturbances. In addition, the likelihood of refuge movements varied among tributaries, suggesting the importance of local environmental differences between tributary and the main stem habitats. This is the first study to experimentally confirm the tributary refuge hypothesis, and underscores the roles of habitat diversity and connectivity during disturbances, even though some habitats are not used during normal conditions.

Do Students Behave Rationally in Multiple Choice Tests? Evidence from a Field Experiment

OpenAIRE

María Paz Espinosa; Javier Gardeazabal

2013-01-01

A disadvantage of multiple choice tests is that students have incentives to guess. To discourage guessing, it is common to use scoring rules that either penalize wrong answers or reward omissions. In psychometrics, penalty and reward scoring rules are considered equivalent. However, experimental evidence indicates that students behave differently under penalty or reward scoring rules. These differences have been attributed to the different framing (penalty versus reward). In this paper, we mo...

Experimental evidence of human recreational disturbance effects on bird-territory establishment.

Science.gov (United States)

Bötsch, Yves; Tablado, Zulima; Jenni, Lukas

2017-07-12

The worldwide increase in human outdoor activities raises concerns for wildlife. Human disturbances, even at low levels, are likely to impact species during sensitive periods of the annual cycle. However, experimental studies during the putative sensitive period of territory establishment of birds which not only investigate low disturbance levels, but which also exclude the effect of habitat modification (e.g. walking trails) are lacking. Here, we experimentally disturbed birds in forest plots by walking through twice a day during territory establishment. Later we compared the breeding bird community of experimentally disturbed plots with that of undisturbed control plots. We discovered that the number of territories (-15.0%) and species richness (-15.2%) in disturbed plots were substantially reduced compared with control plots. Species most affected included those sensitive to human presence (assessed by flight-initiation distances), open-cup nesters and above-ground foragers. Long-distance migrants, however, were unaffected due to their arrival after experimental disturbance took place. These findings highlight how territory establishment is a sensitive period for birds, when even low levels of human recreation may be perceived as threatening, and alter settlement decisions. This can have important implications for the conservation of species, which might go unnoticed when focusing only on already established birds. © 2017 The Author(s).

Quasi-experimental study designs series-paper 4: uses and value.

Science.gov (United States)

Bärnighausen, Till; Tugwell, Peter; Røttingen, John-Arne; Shemilt, Ian; Rockers, Peter; Geldsetzer, Pascal; Lavis, John; Grimshaw, Jeremy; Daniels, Karen; Brown, Annette; Bor, Jacob; Tanner, Jeffery; Rashidian, Arash; Barreto, Mauricio; Vollmer, Sebastian; Atun, Rifat

2017-09-01

Quasi-experimental studies are increasingly used to establish causal relationships in epidemiology and health systems research. Quasi-experimental studies offer important opportunities to increase and improve evidence on causal effects: (1) they can generate causal evidence when randomized controlled trials are impossible; (2) they typically generate causal evidence with a high degree of external validity; (3) they avoid the threats to internal validity that arise when participants in nonblinded experiments change their behavior in response to the experimental assignment to either intervention or control arm (such as compensatory rivalry or resentful demoralization); (4) they are often well suited to generate causal evidence on long-term health outcomes of an intervention, as well as nonhealth outcomes such as economic and social consequences; and (5) they can often generate evidence faster and at lower cost than experiments and other intervention studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Indicators of activity-friendly communities: an evidence-based consensus process.

Science.gov (United States)

Brennan Ramirez, Laura K; Hoehner, Christine M; Brownson, Ross C; Cook, Rebeka; Orleans, C Tracy; Hollander, Marla; Barker, Dianne C; Bors, Philip; Ewing, Reid; Killingsworth, Richard; Petersmarck, Karen; Schmid, Thomas; Wilkinson, William

2006-12-01

Regular physical activity, even at modest intensities, is associated with many health benefits. Most Americans, however, do not engage in the recommended levels. As practitioners seek ways to increase population rates of physical activity, interventions and advocacy efforts are being targeted to the community level. Yet, advocates, community leaders, and researchers lack the tools needed to assess local barriers to and opportunities for more active, healthy lifestyles. Investigators used a systematic review process to identify key indicators of activity-friendly communities that can assess and improve opportunities for regular physical activity. Investigators conducted a comprehensive literature review of both peer-reviewed literature and fugitive information (e.g., reports and websites) to generate an initial list of indicators for review (n=230). The review included a three-tiered, modified Delphi consensus-development process that incorporated input of international, national, state, and local researchers and practitioners from academic institutions, federal and state government agencies, nonprofit organizations, and funding agencies in public health, transportation, urban planning, parks and recreation, and public policy. Ten promising indicators of activity-friendly communities were identified: land use environment, access to exercise facilities, transportation environment, aesthetics, travel patterns, social environment, land use economics, transportation economics, institutional and organizational policies, and promotion. Collaborative, multidisciplinary approaches are underway to test, refine, and expand this initial list of indicators and to develop measures that communities, community leaders, and policymakers can use to design more activity-friendly community environments.

The fungal colonisation of rock-art caves: experimental evidence.

Science.gov (United States)

Jurado, Valme; Fernandez-Cortes, Angel; Cuezva, Soledad; Laiz, Leonila; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio; Saiz-Jimenez, Cesareo

2009-09-01

The conservation of rock-art paintings in European caves is a matter of increasing interest. This derives from the bacterial colonisation of Altamira Cave, Spain and the recent fungal outbreak of Lascaux Cave, France-both included in the UNESCO World Heritage List. Here, we show direct evidence of a fungal colonisation of rock tablets in a testing system exposed in Altamira Cave. After 2 months, the tablets, previously sterilised, were heavily colonised by fungi and bacteria. Most fungi isolated were labelled as entomopathogens, while the bacteria were those regularly identified in the cave. Rock colonisation was probably promoted by the dissolved organic carbon supplied with the dripping and condensation waters and favoured by the displacement of aerosols towards the interior of the cave, which contributed to the dissemination of microorganisms. The role of arthropods in the dispersal of spores may also help in understanding fungal colonisation. This study evidences the fragility of rock-art caves and demonstrates that microorganisms can easily colonise bare rocks and materials introduced into the cavity.

Intra- and Inter-Regional Return and Volatility Spillovers Across Emerging and Developing Markets: Evidence from Stock Indices and Stock Index Futures

OpenAIRE

Yarovaya, Larisa; Brzeszczynski, Janusz; Lau, Marco Chi Keung

2016-01-01

We provide empirical evidence on the patterns of intra- and inter-regional transmission of information across 10 developed and 11 emerging markets in Asia, the Americas, Europe and Africa using both stock indices and stock index futures. The main transmission channels are examined in the period from 2005 to 2014 through the analysis of return and volatility spillovers around the most recent crises based on the generalized vector autoregressive framework. Our findings demonstrate that markets ...

Giant multipole resonances: an experimental review

International Nuclear Information System (INIS)

Bertrand, F.E.

1979-01-01

During the past several years experimental evidence has been published for the existance of nondipole giant resonances. These giant multipole resonances, the so-called new giant resonances were first observed through inelastic hadron and electron scattering and such measurements have continued to provide most of the information in this field. A summary is provided of the experimental evidence for these new resonances. The discussion deals only with results from inelastic scattering and only with the electric multipoles. Emphasis is placed on the recent observations of the giant monopole resonance. Results from recent heavy-ion and pion inelastic scattering are discussed. 38 references

Quality Indicators for Learning Analytics

Science.gov (United States)

Scheffel, Maren; Drachsler, Hendrik; Stoyanov, Slavi; Specht, Marcus

2014-01-01

This article proposes a framework of quality indicators for learning analytics that aims to standardise the evaluation of learning analytics tools and to provide a mean to capture evidence for the impact of learning analytics on educational practices in a standardised manner. The criteria of the framework and its quality indicators are based on…

Improving implementation of evidence-based practice in mental health service delivery: protocol for a cluster randomised quasi-experimental investigation of staff-focused values interventions.

Science.gov (United States)

Williams, Virginia; Oades, Lindsay G; Deane, Frank P; Crowe, Trevor P; Ciarrochi, Joseph; Andresen, Retta

2013-07-02

There is growing acceptance that optimal service provision for individuals with severe and recurrent mental illness requires a complementary focus on medical recovery (i.e., symptom management and general functioning) and personal recovery (i.e., having a 'life worth living'). Despite significant research attention and policy-level support, the translation of this vision of healthcare into changed workplace practice continues to elude. Over the past decade, evidence-based training interventions that seek to enhance the knowledge, attitudes, and skills of staff working in the mental health field have been implemented as a primary redress strategy. However, a large body of multi-disciplinary research indicates disappointing rates of training transfer. There is an absence of empirical research that investigates the importance of worker-motivation in the uptake of desired workplace change initiatives. 'Autonomy' is acknowledged as important to human effectiveness and as a correlate of workplace variables like productivity, and wellbeing. To our knowledge, there have been no studies that investigate purposeful and structured use of values-based interventions to facilitate increased autonomy as a means of promoting enhanced implementation of workplace change. This study involves 200 mental health workers across 22 worksites within five community-managed organisations in three Australian states. It involves cluster-randomisation of participants within organisation, by work site, to the experimental (values) condition, or the control (implementation). Both conditions receive two days of training focusing on an evidence-based framework of mental health service delivery. The experimental group receives a third day of values-focused intervention and 12 months of values-focused coaching. Well-validated self-report measures are used to explore variables related to values concordance, autonomy, and self-reported implementation success. Audits of work files and staff work samples

Plain packaging of cigarettes: do we have sufficient evidence?

Directory of Open Access Journals (Sweden)

Smith CN

2015-04-01

Full Text Available Collin N Smith,1 John D Kraemer,2 Andrea C Johnson,1 Darren Mays1 1Department of Oncology, Georgetown University Medical Center, Lombardi Comprehensive Cancer Center, Washington, DC, USA; 2Department of Health Systems Administration, School of Nursing and Health Studies, Georgetown University, Washington, DC, USA Abstract: Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. Keywords: cigarette smoking, tobacco, plain packaging, regulation, policy

Self-transcendence facilitates meaning-making and flow: Evidence from a pilot experimental study

Directory of Open Access Journals (Sweden)

Osin, Evgeny N.

2016-06-01

Full Text Available We review the psychological theory of flow and focus on the notion of the autotelic personality, arguing that self-transcendence (understood within the existential tradition of Frankl and Längle as the individual’s ability to establish inner relationships with values can be viewed as a personality disposition conducive to flow experience. The study aimed to investigate the effects of situational task meaning and dispositional self-transcendence on productivity and flow experience. We present a pilot quasi-experimental study conducted in a student sample (N = 82 Students were asked to work in small-group settings on a creative task, which consisted in finding solutions to a social problem. Each group was randomly assigned to an instruction presenting the problem as happening either in a distant country (low-meaning or in their home country (high-meaning condition. The outcome variables were measures of flow, perceived meaning of the task, and satisfaction with time spent working. The solutions generated by the students were rated by three experts. The experimental manipulation had a main effect on the quality of the resulting solutions, but not on the subjective experience of the participants. A number of significant interaction effects were found, indicating that the associations of self-transcendence with experiential outcomes tended to be linear under the low-meaning condition, but curvilinear under the high-meaning condition. The findings suggest that self-transcendence is particularly beneficial to flow in situations with unclear meaning, but very high levels of self-transcendence may hinder flow in highly meaningful situations. Overall, the findings suggest that self-transcendence can be considered as a disposition of the autotelic personality.

Strategic sophistication of individuals and teams. Experimental evidence

Science.gov (United States)

Sutter, Matthias; Czermak, Simon; Feri, Francesco

2013-01-01

Many important decisions require strategic sophistication. We examine experimentally whether teams act more strategically than individuals. We let individuals and teams make choices in simple games, and also elicit first- and second-order beliefs. We find that teams play the Nash equilibrium strategy significantly more often, and their choices are more often a best response to stated first order beliefs. Distributional preferences make equilibrium play less likely. Using a mixture model, the estimated probability to play strategically is 62% for teams, but only 40% for individuals. A model of noisy introspection reveals that teams differ from individuals in higher order beliefs. PMID:24926100

Forensic Geopedology and Micropedology: New Indications and Lookouts from Pigs Experimental Burials.

Science.gov (United States)

Ern, Stephania Irmgard Elena; Trombino, Luca

2013-04-01

The role played by soil scientists in the modern forensic science is very real and important, above all in the crime scenes when buried remains, both strongly decomposed or skeletal, are found. Thanks to a PhD project on Forensic Geopedology, an interdisciplinary team of the Universities of Milano and Milano Bicocca, has been working for the last four years on several sets of experimental burials of pigs and piglets, in different soil types and for different times of burial, in order to get new evidences on environmental responses to the burial, including geopedological and micropedological aspects. The present work constitutes a conclusive synthesis of results emerged from comparative soil characterizations, listed as follow: - Grainsize analyses; - Determination of pH in H2O and KCl; - Total Nitrogen and Organic Carbon analyses: - Quantification of Available Phosphorous; - Determination of Cation Exchange Capacity and Base Saturation; - Analyses of Volatile Fatty Acids; - Scanning Electron Microscope and Energy Dispersive Spectroscopy analyses; - Petrographic Optical Microscope analyses (including thin sections descriptions). It is proposed a diachronic picture of the project where it is possible to follow the variability of significance of the different kinds of analyses carried out. The achieved results, especially when cross-checked, are very stimulating as regards the setting of analytical protocols for: - The determination of time since burial (TSB); - The discrimination between primary and secondary burials; - The identification of corpses concealments. All the analyses and different approaches discussed and addressed in this work require extreme care when applied to real forensic scenarios; however, the protocols tested can be a piece of a large and articulated puzzle that depicts the major forensic case studies in which Geopedology can be of help in solving problems or in answering some peculiar questions. It is important to understand that a science so

Core-meltdown experimental review

International Nuclear Information System (INIS)

1975-08-01

The results of a study of the experimental evidence having a bearing on hypothetical core meltdowns in light-water reactors are presented. The first objective of the study was to obtain a compendium of the experimental evidence applicable to the analysis of a hypothetical core meltdown. Literature from the nuclear power field and from other scientific disciplines and industrial sources was reviewed. Investigators and other persons knowledgeable in the subject were interviewed. A second objective was to determine what data are required and to determine the adequacy of existing data. In core-meltdown studies only land-based plants have been examined. A third, and final, task of this study was to examine offshore plants to determine applicability of onshore plant analysis to particular areas therein and to determine what information peculiar to meltdown accidents in offshore plants was needed. (U.S.)

Testing the environmental Kuznets curve hypothesis with bird populations as habitat-specific environmental indicators: evidence from Canada.

Science.gov (United States)

Lantz, Van; Martínez-Espiñeira, Roberto

2008-04-01

The traditional environmental Kuznets curve (EKC) hypothesis postulates that environmental degradation follows an inverted U-shaped relationship with gross domestic product (GDP) per capita. We tested the EKC hypothesis with bird populations in 5 different habitats as environmental quality indicators. Because birds are considered environmental goods, for them the EKC hypothesis would instead be associated with a U-shaped relationship between bird populations and GDP per capita. In keeping with the literature, we included other variables in the analysis-namely, human population density and time index variables (the latter variable captured the impact of persistent and exogenous climate and/or policy changes on bird populations over time). Using data from 9 Canadian provinces gathered over 37 years, we used a generalized least-squares regression for each bird habitat type, which accounted for the panel structure of the data, the cross-sectional dependence across provinces in the residuals, heteroskedasticity, and fixed- or random-effect specifications of the models. We found evidence that supports the EKC hypothesis for 3 of the 5 bird population habitat types. In addition, the relationship between human population density and the different bird populations varied, which emphasizes the complex nature of the impact that human populations have on the environment. The relationship between the time-index variable and the different bird populations also varied, which indicates there are other persistent and significant influences on bird populations over time. Overall our EKC results were consistent with those found for threatened bird species, indicating that economic prosperity does indeed act to benefit some bird populations.

Evaluating quality indicators for patients with community-acquired pneumonia.

Science.gov (United States)

Rhew, D C; Goetz, M B; Shekelle, P G

2001-11-01

Several organizations have published evidence-based quality indicators for community-acquired pneumonia (CAP). However, there is variability in the types of indicators presented between organizations and the level of supporting evidence for each of the indicators. A systematic review of the literature and relevant Internet Web sites was performed to identify quality indicators for CAP that have been proposed or recommended by organizations, and each of the indicators was then critically appraised, using a well-defined set of criteria. The MEDLINE, EMBASE, Best Evidence, and Cochrane Systematic Review databases and Internet Web sites were searched for articles and guidelines published between January 1980 and May 2001 to identify quality indicators for CAP and relevant evidence. Experts in the area of health services research were contacted to identify additional sources. A well-defined set of criteria was applied to evaluate each of the quality indicators. The systematic review of the literature and Internet Web sites yielded 44 CAP-specific quality indicators. The critical appraisal of these indicators yielded 16 indicators that were supported by a study that identified an association between quality of care and the process of care or outcome measure, were applied to enough patients to be able to detect clinically meaningful differences, were clinically and/or economically relevant, were measurable in a clinical practice setting, and were precise in their specifications. Many organizations recommend indicators for CAP. Indicators may serve as measures of clinical performance for clinicians and hospitals, may help in benchmarking, and may ultimately facilitate improvements in quality of care and cost reductions. However, CAP indicators often vary in their meaningfulness, scientific soundness, and interpretability of results. A set of five critical appraisal questions may assist in the evaluation of which quality indicators are most valid.

Experimental evidence of high pressure decoupling between charge transport and structural dynamics in a protic ionic glass-former.

Science.gov (United States)

Wojnarowska, Z; Rams-Baron, M; Knapik-Kowalczuk, J; Połatyńska, A; Pochylski, M; Gapinski, J; Patkowski, A; Wlodarczyk, P; Paluch, M

2017-08-01

In this paper the relaxation dynamics of ionic glass-former acebutolol hydrochloride (ACB-HCl) is studied as a function of temperature and pressure by using dynamic light scattering and broadband dielectric spectroscopy. These unique experimental data provide the first direct evidence that the decoupling between the charge transport and structural relaxation exists in proton conductors over a wide T-P thermodynamic space, with the time scale of structural relaxation being constant at the liquid-glass transition (τ α  = 1000 s). We demonstrate that the enhanced proton transport, being a combination of intermolecular H + hopping between cation and anion as well as tautomerization process within amide moiety of ACB molecule, results in a breakdown of the Stokes-Einstein relation at ambient and elevated pressure with the fractional exponent k being pressure dependent. The dT g /dP coefficient, stretching exponent β KWW and dynamic modulus E a /ΔV # were found to be the same regardless of the relaxation processes studied. This is in contrast to the apparent activation volume parameter that is different when charge transport and structural dynamics are considered. These experimental results together with theoretical considerations create new ideas to design efficient proton conductors for potential electrochemical applications.

What role can information play in improved equity in Pakistan's irrigation system? Evidence from an experimental game in Punjab

Directory of Open Access Journals (Sweden)

Andrew Reid. Bell

2015-03-01

Full Text Available The Indus Basin Irrigation System suffers significant inequity in access to surface water across its millions of users. Information, i.e., monitoring and reporting of water availability, may be of value in improving conditions across the basin, and we investigated this via an experimental game of water distribution in Punjab, Pakistan. We found evidence that flow information allowed players to take more effective action to target overuse, and that overall activities that might bring social disapproval were reduced with information. However, we did not find any overall improvement in equity across the system, suggesting that information on its own might not be sufficient to lead to better water distribution among irrigators.

[Indication for mitral valve interventions: Development of a quality indicator for external hospital quality assurance].

Science.gov (United States)

Köster, Christina; Schorbach, Lena; Wrede, Stephanie; Meyer, Sven; Kazmaier, Tonia; Szecsenyi, Joachim

2017-11-01

The indication for a mitral valve intervention is an important patient-relevant parameter for the assessment of process quality and the comparison of healthcare providers. In this article, we describe the development of a corresponding quality indicator for an external hospital quality assurance (QA) procedure in Germany. An expert panel was set up by the aQua Institute to assist with the development of a QA procedure for mitral valve interventions and the associated quality indicators. In a comprehensive, systematic literature and evidence research, the American and European guidelines were identified as the best evidence available. Especially the more current American guideline formed the basis on which a quality indicator dealing with the correct indication for a mitral valve intervention was developed. The developed quality indicator assesses the proportion of patients for whom an indication for a mitral valve intervention was determined in compliance with guideline recommendations. The indicator differentiates between surgical and catheter-based procedures. To determine whether or not the indication was correct, different medical parameters are included, such as, for example, type of mitral valve defect, etiology of the disease, severity of symptoms, valve morphology (e. g., mitral valve area), valve hemodynamics and comorbidity, which healthcare providers have to document. The documentation for the developed quality indicator is considerable. Nonetheless, its relevance is undeniable because it allows the user to determine whether a surgical or catheter-based mitral valve intervention was necessary and performed according to guideline recommendations. In the first year of its implementation, this indicator should be evaluated for further improvement and simplification of assessment. Copyright © 2017. Published by Elsevier GmbH.

Experimental Investigations of the Energy and Environmental Indices of Operation of a Low-Capacity Combined Gas Producer and Hot-Water Boiler

Science.gov (United States)

Bodnar, L. A.; Stepanov, D. V.; Dovgal‧, A. N.

2015-07-01

It has been shown that the introduction of combined gas producers and boilers on renewable energy sources is a pressing issue. A structural diagram of a low-capacity combined gas producer and boiler on renewable energy sources has been given; a bench and procedures for investigation and processing of results have been developed. Experimental investigations of the energy and environmental indices of a 40-kW combined gas producer and hotwater boiler burning wood have been carried out. Results of the experimental investigations have been analyzed. Distinctive features have been established and a procedure of thermal calculation of the double furnace of a lowcapacity combined gas producer and boiler burning solid fuel has been proposed. The calculated coefficients of heat transfer from the gases in the convection bank have been compared with the obtained experimental results. A calculation dependence for the heat transfer from the gases in convection banks of low-capacity hot-water boilers has been proposed. The quantities of harmful emissions from the combined gas producer and boiler on renewable energy sources have been compared with the existing Ukrainian and foreign standards. It has been established that the environmental efficiency of the boiler under study complies with most of the standard requirements of European countries.

Pediatric Obstructive Sleep Apnea and the critical role of oral-facial growth: evidences

Directory of Open Access Journals (Sweden)

Christian eGuilleminault

2013-01-01

Full Text Available Aims: Review of evidence in support of an oral-facial growth impairment in the development of pediatric sleep apnea in non-obese childrenMethod: Review of experimental data from infant monkeys with experimentally induced nasal resistance. Review of early historical data in the orthodontic literature indicating the abnormal oral-facial development associated with mouth breathing and nasal resistance. Review of the progressive demonstration of sleep disordered breathing in children who underwent incomplete treatment of OSA with adenotonsillectomy, and demonstration of abnormal oral-facial anatomy that must often to be treated in order for the resolution of OSA. Review of long term recurrence data on OSA and indication of oral-facial myofunctional dysfunction in association with the recurrence of OSA. Results: Presentation of prospective data on premature infants and sleep-disordered-breathing (SDB-treated children, supporting the concept of oral-facial hypotonia. Presentation of evidence supporting hypotonia as a primary element in the development of oral-facial anatomic abnormalities leading to abnormal breathing during sleep. Continuous interaction between oral facial muscle tone, maxillary-mandibular growth and development of SDB. Role of myofunctional re-education with orthodontics and elimination of upper airway soft tissue in the treatment of non-obese SDB children. Conclusion: Pediatric OSA in non-obese children is a disorder of oral facial growth.

Experimental evidence for convergent evolution of maternal care heuristics in industrialized and small-scale populations.

Science.gov (United States)

Kushnick, Geoff; Hanowell, Ben; Kim, Jun-Hong; Langstieh, Banrida; Magnano, Vittorio; Oláh, Katalin

2015-06-01

Maternal care decision rules should evolve responsiveness to factors impinging on the fitness pay-offs of care. Because the caretaking environments common in industrialized and small-scale societies vary in predictable ways, we hypothesize that heuristics guiding maternal behaviour will also differ between these two types of populations. We used a factorial vignette experiment to elicit third-party judgements about likely caretaking decisions of a hypothetical mother and her child when various fitness-relevant factors (maternal age and access to resources, and offspring age, sex and quality) were varied systematically in seven populations-three industrialized and four small-scale. Despite considerable variation in responses, we found that three of five main effects, and the two severity effects, exhibited statistically significant industrialized/ small-scale population differences. All differences could be explained as adaptive solutions to industrialized versus small-scale caretaking environments. Further, we found gradients in the relationship between the population-specific estimates and national-level socio-economic indicators, further implicating important aspects of the variation in industrialized and small-scale caretaking environments in shaping heuristics. Although there is mounting evidence for a genetic component to human maternal behaviour, there is no current evidence for interpopulation variation in candidate genes. We nonetheless suggest that heuristics guiding maternal behaviour in diverse societies emerge via convergent evolution in response to similar selective pressures.

Autism as the Low-Fitness Extreme of a Parentally Selected Fitness Indicator.

Science.gov (United States)

Shaner, Andrew; Miller, Geoffrey; Mintz, Jim

2008-12-01

Siblings compete for parental care and feeding, while parents must allocate scarce resources to those offspring most likely to survive and reproduce. This could cause offspring to evolve traits that advertise health, and thereby attract parental resources. For example, experimental evidence suggests that bright orange filaments covering the heads of North American coot chicks may have evolved for this fitness-advertising purpose. Could any human mental disorders be the equivalent of dull filaments in coot chicks-low-fitness extremes of mental abilities that evolved as fitness indicators? One possibility is autism. Suppose that the ability of very young children to charm their parents evolved as a parentally selected fitness indicator. Young children would vary greatly in their ability to charm parents, that variation would correlate with underlying fitness, and autism could be the low-fitness extreme of this variation. This view explains many seemingly disparate facts about autism and leads to some surprising and testable predictions.

A first-approximation urban-air-quality indicator

Science.gov (United States)

David M. Paproski; Julian R. Walker

1977-01-01

Development of the first-approximation-urban-air-quality indicator was reported by the Economic Council of Canada. The indicator takes account of ambient concentrations of five pollutants: sulfur dioxide, particulate matter, oxides of nitrogen, carbon monoxide, and total oxidants. Epidemiological evidence indicating the potential impact of these pollutants on human...

Nordic eHealth Indicators

DEFF Research Database (Denmark)

Hyppönen, Hannele; Faxvaag, Arild; Gilstad, Heidi

This report describes first results of the Network: eHealth policy analysis and first common Nordic eHealth indicators. The results show similarities and also some differences in the eHealth policies, priorities and implementation. Interesting similarities and differences in availability and use...... of eHealth services in the Nordic countries were found with the first comparable eHealth indicators. The results create a basis for Evidence-based policy making as well as benchmarking and learning best practices from each other....

The Impact of Smoking Bans on Smoking and Consumer Behavior: Quasi-Experimental Evidence from Switzerland.

Science.gov (United States)

Boes, Stefan; Marti, Joachim; Maclean, Johanna Catherine

2015-11-01

In this paper, we exploit the progressive implementation of smoking bans in public venues at the state level in Switzerland to evaluate both the direct effects on smoking and the potential unintended consequences of these legislations on consumer behaviors as measured by visiting restaurants/bars and discos ('going out'). Our results indicate that public venue smoking bans in Switzerland reduce smoking rates, but the findings do not emerge until 1 year following the ban. This pattern of results is consistent with delays in ban enforcement on the part of business owners, difficulties in changing addictive behaviors such as smoking, and/or learning on the part of smokers. We find evidence that smoking bans influence going-out behavior and there is substantial heterogeneity across venue and consumer characteristics. Copyright © 2014 John Wiley & Sons, Ltd.

Tax-Rate Biases in Tax-Planning Decisions: Experimental Evidence

OpenAIRE

Amberger, Harald; Eberhartinger, Eva; Kasper, Helmut

2016-01-01

Contrary to standard economic theory, recent empirical findings suggest that firms do not always engage in economically optimal tax planning. We conduct a laboratory experiment and find robust evidence that decision biases offer a behavioral explanation for suboptimal tax planning. When facing time pressure in an intra-group cross-border financing decision, subjects apply heuristics based on the salience of statutory tax rates. This stirs decision makers to underestimate the effects of tax-ba...

Risk, Credit, and Insurance in Peru: Field Experimental Evidence

OpenAIRE

Galarza, Francisco

2009-01-01

This paper reports the results of behavioral economic experiments conducted in Peru to examine the relationship amongst risk preferences, loan take-up, and insurance purchase decisions. This area-based yield insurance can help reduce people's vulnerability to large scale covariate shocks, and can also lower the loan default probability under extreme negative covariate shocks. In a context of collateralized formal credit markets, we provide suggestive evidence that insurance may help reduce th...

Adaptive synonymous mutations in an experimentally evolved Pseudomonas fluorescens population

DEFF Research Database (Denmark)

Bailey, Susan; Hinz, Aaron; Kassen, Rees

2014-01-01

Conventional wisdom holds that synonymous mutations, nucleotide changes that do not alter the encoded amino acid, have no detectable effect on phenotype or fitness. However, a growing body of evidence from both comparative and experimental studies suggests otherwise. Synonymous mutations have been...... shown to impact gene expression, protein folding and fitness, however, direct evidence that they can be positively selected, and so contribute to adaptation, is lacking. Here we report the recovery of two beneficial synonymous single base pair changes that arose spontaneously and independently...... in an experimentally evolved population of Pseudomonas fluorescens. We show experimentally that these mutations increase fitness by an amount comparable to non-synonymous mutations and that the fitness increases stem from increased gene expression. These results provide unequivocal evidence that synonymous mutations...

Experimental evidence for density dependence of reproduction in great tits

NARCIS (Netherlands)

Both, C.

1998-01-01

1. Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not

The effects of prosocial video games on prosocial behaviors: international evidence from correlational, longitudinal, and experimental studies.

Science.gov (United States)

Gentile, Douglas A; Anderson, Craig A; Yukawa, Shintaro; Ihori, Nobuko; Saleem, Muniba; Ming, Lim Kam; Shibuya, Akiko; Liau, Albert K; Khoo, Angeline; Bushman, Brad J; Rowell Huesmann, L; Sakamoto, Akira

2009-06-01

Although dozens of studies have documented a relationship between violent video games and aggressive behaviors, very little attention has been paid to potential effects of prosocial games. Theoretically, games in which game characters help and support each other in nonviolent ways should increase both short-term and long-term prosocial behaviors. We report three studies conducted in three countries with three age groups to test this hypothesis. In the correlational study, Singaporean middle-school students who played more prosocial games behaved more prosocially. In the two longitudinal samples of Japanese children and adolescents, prosocial game play predicted later increases in prosocial behavior. In the experimental study, U.S. undergraduates randomly assigned to play prosocial games behaved more prosocially toward another student. These similar results across different methodologies, ages, and cultures provide robust evidence of a prosocial game content effect, and they provide support for the General Learning Model.

The Effects of Prosocial Video Games on Prosocial Behaviors: International Evidence from Correlational, Longitudinal, and Experimental Studies

Science.gov (United States)

Gentile, Douglas A.; Anderson, Craig A.; Yukawa, Shintaro; Ihori, Nobuko; Saleem, Muniba; Ming, Lim Kam; Shibuya, Akiko; Liau, Albert K.; Khoo, Angeline; Bushman, Brad J.; Huesmann, L. Rowell; Sakamoto, Akira

2009-01-01

Although dozens of studies have documented a relation between violent video games and aggressive behaviors, very little attention has been paid to potential effects of prosocial games. Theoretically, games in which game characters help and support each other in nonviolent ways should increase both short-term and long-term prosocial behaviors. We report three studies conducted in three countries with three age groups to test this hypothesis. In the correlational study, Singaporean middle-school students who played more prosocial games behaved more prosocially. In the two longitudinal samples of Japanese children and adolescents, prosocial game play predicted later increases in prosocial behavior. In the experimental study, U.S. undergraduates randomly assigned to play prosocial games behaved more prosocially toward another student. These similar results across different methodologies, ages, and cultures provide robust evidence a prosocial game content effect, and provide support for the General Learning Model. PMID:19321812

Experimental evidence for density dependence of reproduction in great tits

NARCIS (Netherlands)

Both, Christiaan

1998-01-01

1.  Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not

Experimental evidence for suspence as determinant of video game enjoyment

NARCIS (Netherlands)

Klimmt, C.; Rizzo, A.; Vorderer, P.A.; Koch, J.; Fischer, T.

2009-01-01

Based on theoretical assumptions from film psychology and their application to video games, the hypothesis is tested that suspense is a major factor in video game enjoyment. A first-person shooter game was experimentally manipulated to create either a low level or a high level of suspense.

Granger Causality between Stock Market and Macroeconomic Indicators: Evidence from Germany

Directory of Open Access Journals (Sweden)

Tomáš Plíhal

2016-01-01

Full Text Available The aim of this paper is to investigate informational efficiency of the stock market in Germany. Granger causality between the stock market and the selected macroeconomic variables is investigated by bivariate analysis using Toda-Yamamoto (1995 approach. This study focuses on monthly data from January 1999 to September 2015, and the stock market is represented by blue chip stock market index DAX. Investigated macroeconomic indicators include industrial production, inflation, money supply, interest rate, trade balance and exchange rate. Stock market Granger-causes industrial production and interest rate, and is therefore leading indicator of these variables. Between money supply and stock prices is Granger causality in both directions. Other variables seem to be independent on development of the stock market. We do not find any violation of Efficient market hypothesis which indicates that the stock market in Germany is informational efficient.

Experimental evidence for partial spatial coherence in imaging Mueller polarimetry.

Science.gov (United States)

Ossikovski, Razvigor; Arteaga, Oriol; Yoo, Sang Hyuk; Garcia-Caurel, Enric; Hingerl, Kurt

2017-11-15

We demonstrate experimentally the validity of the partial spatial coherence formalism in Mueller polarimetry and show that, in a finite spatial resolution experiment, the measured response is obtained through convolving the theoretical one with the instrument function. The reported results are of primary importance for Mueller imaging systems.

Management and organizational indicators of process safety

International Nuclear Information System (INIS)

Van Hemel, S.B.; Connelly, E.M.; Haas, P.M.

1991-01-01

This study is part of a Nuclear Regulatory Commission research element on organizational factors in plant safety under the Human Factors research program. This paper reports that the study investigated the chemical industry, to find leading management or organizational tools which could be useful for the NRC. After collecting information form a variety of information sources, the authors concentrated our study on two types of indicators currently in use: the first is audit- or review-based, and concentrates on programmatic factors; the second, based on frequent behavioral observations, concentrates on the management of individual worker behaviors. The authors analyzed data on the relationships between the leading indictors and direct indictors such as accident and injury rates in three case studies, to determine whether sufficient evidence of validity and utility exists to justify consideration of these indicators as public safety indicators. This paper states that on the basis of statistical associations and other evidence, the authors concluded that the two indicator types have promise for use as plant safety performance indicators, and that further development and testing of the candidate indicators should be performed

Discriminating evidence accumulation from urgency signals in speeded decision making.

Science.gov (United States)

Hawkins, Guy E; Wagenmakers, Eric-Jan; Ratcliff, Roger; Brown, Scott D

2015-07-01

The dominant theoretical paradigm in explaining decision making throughout both neuroscience and cognitive science is known as “evidence accumulation”--The core idea being that decisions are reached by a gradual accumulation of noisy information. Although this notion has been supported by hundreds of experiments over decades of study, a recent theory proposes that the fundamental assumption of evidence accumulation requires revision. The "urgency gating" model assumes decisions are made without accumulating evidence, using only moment-by-moment information. Under this assumption, the successful history of evidence accumulation models is explained by asserting that the two models are mathematically identical in standard experimental procedures. We demonstrate that this proof of equivalence is incorrect, and that the models are not identical, even when both models are augmented with realistic extra assumptions. We also demonstrate that the two models can be perfectly distinguished in realistic simulated experimental designs, and in two real data sets; the evidence accumulation model provided the best account for one data set, and the urgency gating model for the other. A positive outcome is that the opposing modeling approaches can be fruitfully investigated without wholesale change to the standard experimental paradigms. We conclude that future research must establish whether the urgency gating model enjoys the same empirical support in the standard experimental paradigms that evidence accumulation models have gathered over decades of study. Copyright © 2015 the American Physiological Society.

[Effort-reward imbalance at work and depression: current research evidence].

Science.gov (United States)

Siegrist, J

2013-01-01

In view of highly prevalent stressful conditions in modern working life, in particular increasing work pressure and job insecurity, it is of interest to know whether specific constellations of an adverse psychosocial work environment increase the risk of depressive disorder among employed people. This contribution gives a short overview of current research evidence based on an internationally established work stress model of effort-reward imbalance. Taken together, results from seven prospective epidemiological investigations demonstrate a two-fold elevated relative risk of incident depressive disorder over a mean observation period of 2.7 years among exposed versus non-exposed employees. Additional findings from experimental and quasi-experimental studies point to robust associations of effort-reward imbalance at work with proinflammatory cytokines and markers of reduced immune competence. These latter markers may indicate potential psychobiological pathways. In conclusion, incorporating this new knowledge into medical treatment and preventive efforts seems well justified.

Experimental densities, refractive indices, and speeds of sound of 12 binary mixtures containing alkanes and aromatic compounds at T = 313.15 K

International Nuclear Information System (INIS)

Calvar, Noelia; Gomez, Elena; Gonzalez, Begona; Dominguez, Angeles

2009-01-01

Densities, speeds of sound, and refractive indices of 12 binary systems of alkanes (hexane, heptane, octane, and nonane) with aromatics (benzene, or toluene, or ethylbenzene) at T = 313.15 K and at atmospheric pressure were determined over the whole composition range, and are presented in this paper. From the experimental results, the derived and excess properties (isentropic compressibility, excess molar volumes, and excess molar isentropic compressibility) at T = 313.15 K were calculated and satisfactorily fitted to the Redlich-Kister equation.

Experimental Evidence on the Effects of Early Meetings and Activation

DEFF Research Database (Denmark)

Pedersen, Jonas Maibom; Rosholm, Michael; Svarer, Michael

and case workers increase employment rates over the next two years by 10%. For men, we find evidence of a threat effect of having to participate in early activation programmes. In general, we find large differences between men and women, especially in the dynamics of the effects. A cost-benefit analysis...

Granular biodurable nanomaterials: No convincing evidence for systemic toxicity.

Science.gov (United States)

Moreno-Horn, Marcus; Gebel, Thomas

2014-11-01

Nanomaterials are usually defined by primary particle diameters ranging from 1 to 100 nm. The scope of this review is an evaluation of experimental animal studies dealing with the systemic levels and putative systemic effects induced by nanoparticles which can be characterized as being granular biodurable particles without known specific toxicity (GBP). Relevant examples of such materials comprise nanosized titanium dioxide (TiO2) and carbon black. The question was raised whether GBP nanomaterials systemically accumulate and may possess a relevant systemic toxicity. With few exceptions, the 56 publications reviewed were not performed using established standard protocols, for example, OECD guidelines but used non-standard study designs. The studies including kinetic investigations indicated that GBP nanomaterials were absorbed and systemically distributed to rather low portions only. There was no valid indication that GPB nanomaterials possess novel toxicological hazard properties. In addition, no convincing evidence for a relevant specific systemic toxicity of GBP nanomaterials could be identified. The minority of the papers reviewed (15/56) investigated both nanosized and microsized GBP materials in parallel. A relevant different translocation of GBP nanomaterials in contrast to GBP micromaterials was not observed in these studies. There was no evidence that GPB nanomaterials possess toxicological properties other than their micromaterial counterparts.

Theoretical and Experimental Results Regarding LENR/CF

International Nuclear Information System (INIS)

Robert W. Bass; Wm. Stan Gleeson

2000-01-01

We challenge the predominant view that low-energy nuclear reactions (LENRs) are prohibited by standard quantum mechanics (QM). This view, supposedly based on standard nuclear theory, need not apply in condensed-matter environments. These considerations indicate that seemingly novel experimental evidence of rapid aneutronic bulk-process transmutation, at extraordinarily low-energy levels, in a simple electrochemical reactor, can occur. This explains: (a) induced rapid decay of radioactive thorium into stable nuclides, e.g., Cu and (b) resulting, anomalous distribution of Cu isotopes. We reexamine arguments of Peebles cited as evidence that standard QM 'forbids' cold fusion (CF). We note oversimplifications in those and present an alternative, more sophisticated calculation (see Bass, Refs. 3 through 8) demonstrating that conventional wisdom about impenetrability of the 'Coulomb barrier' fails as a result of periodic-order-induced resonance. We also examine empirical evidence. In three independent tests of an LENR electrolysis cell, using different I-V-T (current/voltage/time) protocols, the percentage of radiation reduction (RR) transmutation achieved η=[23%, 50%, 83%] versus expended energy E=[0.6535, 32.5, 74.6] (Watt-hours), obtained by numerical integration of recorded product I · V for processing time T, provides near-perfect straight-line correlation: η=α·E + η 0 , α=0.8105, η 0 =22.888, (0.65 < E < 0.75)

Competency Assessment Using Key Performance Indicators

OpenAIRE

Elena Alexandra Toader; Laura Brad

2015-01-01

The paper proposes a method for computing the scores of the key performance indicators resulted in the competency assessment process. The key performance indicators are estimated considering four performance levels that an IT professional can obtain at the end of the assessment process. We suggest as the best approach for estimating the performance key indicators an online questionnaire filled by 60 employees that work in IT Romanian companies. The results provide evidence that the difference...

Spray drift of pesticides and stream macroinvertebrates: Experimental evidence of impacts and effectiveness of mitigation measures

Energy Technology Data Exchange (ETDEWEB)

Maltby, Lorraine [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)], E-mail: l.maltby@sheffield.ac.uk; Hills, Louise [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)

2008-12-15

Impoverished stream communities in agricultural landscapes have been associated with pesticide contamination, but conclusive evidence of causality is rare. We address this deficiency by adopting an experimental approach to investigate the effects of the insecticides cypermethrin and chlorpyrifos on benthic macroinvertebrates. Three treatments were established and a combination of biomarker, bioassay and biomonitoring approaches was employed to investigate, individual, population and community-level effects. Animals deployed during pesticide application had altered enzyme activity, depressed feeding rate and reduced survival, but these effects were only observed where pesticide was sprayed to the stream edge. There were no clear pesticide-related effects on macroinvertebrate community structure or on the population densities of individual species. Hence, short-term pesticide exposure did cause individual-level effects in stream macroinvertebrates, but these were not translated to effects at the population or community-level and were effectively mitigated by the adoption of a no-spray buffer zone. - Pulsed pesticide exposures via spray drift adversely affected stream invertebrates but did not cause population or community-level effects and were mitigated by no-spray buffer zones.

Experimental violation of entropic inequalities

International Nuclear Information System (INIS)

Bovino, F.A.; Castagnoli, G.; Ekert, A.; Horodecki, P.; Alves, C.M.; Sergienko, A.V.

2005-01-01

Full text: We report the experimental evidence that polarization entangled photons violate the inequality based on Renyi entropy. Our experimental method is based on four-photon coincidences in photon bunching and antibunching effects. We introduce an additional 'phase marking' technique, which allow observing the violation of the inequalities even with non-deterministic sources of entangled photons. Our method can be applied to measure selected non-linear properties of bipartite quantum states, such as purity or entanglement. (author)

Experimental evidence of lateral flow in unsaturated homogeneous isotropic sloping soil due to rainfall

Science.gov (United States)

Sinai, G.; Dirksen, C.

2006-12-01

This paper describes laboratory experimental evidence for lateral flow in the top layer of unsaturated sloping soil due to rainfall. Water was applied uniformly on horizontal and V-shaped surfaces of fine sand, at rates about 100 times smaller than the saturated hydraulic conductivity. Flow regimes near the surface and in the soil bulk were studied by using dyes. Streamlines and streak lines and wetting fronts were visually studied and photographed through a vertical glass wall. Near wetting fronts the flow direction was always perpendicular to the fronts owing to dominant matrix potential gradients. Thus, during early wetting of dry sloping sand, the flow direction is directed upslope. Far above a wetting front the flow was vertical due to the dominance of gravity. Downslope flow was observed during decreasing rainfall and dry periods. The lateral movement was largest near the soil surface and decayed with soil depth. Unstable downslope lateral flow close to the soil surface was attributed to non-Darcian flow due to variable temporal and spatial raindrop distributions. The experiments verify the theory that predicts unsaturated downslope lateral flow in sloping soil due to rainfall dynamics only, without apparent soil texture difference or anisotropy. This phenomenon could have significant implications for hillside hydrology, desert agriculture, irrigation management, etc., as well as for the basic mechanisms of surface runoff and erosion.

Context-dependent cheating: Experimental evidence from 16 countries

NARCIS (Netherlands)

Pascual-ezama, David; Fosgaard, Toke R.; Cardenas, Juan Camilo; Kujal, Praveen; Veszteg, Robert; Gil-gómez De Liaño, Beatriz; Gunia, Brian; Weichselbaumer, Doris; Hilken, Katharina; Antinyan, Armenak; Delnoij, Joyce|info:eu-repo/dai/nl/371752213; Proestakis, Antonios; Tira, Michael D.; Pratomo, Yulius; Jaber-lópez, Tarek; Brañas-garza, Pablo

2015-01-01

Policy makers use several international indices that characterize countries according to the quality of their institutions. However, no effort has been made to study how the honesty of citizens varies across countries. This paper explores the honesty among citizens across 16 countries with 1440

The price elasticity of demand for heroin: Matched longitudinal and experimental evidence.

Science.gov (United States)

Olmstead, Todd A; Alessi, Sheila M; Kline, Brendan; Pacula, Rosalie Liccardo; Petry, Nancy M

2015-05-01

This paper reports estimates of the price elasticity of demand for heroin based on a newly constructed dataset. The dataset has two matched components concerning the same sample of regular heroin users: longitudinal information about real-world heroin demand (actual price and actual quantity at daily intervals for each heroin user in the sample) and experimental information about laboratory heroin demand (elicited by presenting the same heroin users with scenarios in a laboratory setting). Two empirical strategies are used to estimate the price elasticity of demand for heroin. The first strategy exploits the idiosyncratic variation in the price experienced by a heroin user over time that occurs in markets for illegal drugs. The second strategy exploits the experimentally induced variation in price experienced by a heroin user across experimental scenarios. Both empirical strategies result in the estimate that the conditional price elasticity of demand for heroin is approximately -0.80. Copyright © 2015 Elsevier B.V. All rights reserved.

The price elasticity of demand for heroin: matched longitudinal and experimental evidence#

Science.gov (United States)

Olmstead, Todd A.; Alessi, Sheila M.; Kline, Brendan; Pacula, Rosalie Liccardo; Petry, Nancy M.

2015-01-01

This paper reports estimates of the price elasticity of demand for heroin based on a newly constructed dataset. The dataset has two matched components concerning the same sample of regular heroin users: longitudinal information about real-world heroin demand (actual price and actual quantity at daily intervals for each heroin user in the sample) and experimental information about laboratory heroin demand (elicited by presenting the same heroin users with scenarios in a laboratory setting). Two empirical strategies are used to estimate the price elasticity of demand for heroin. The first strategy exploits the idiosyncratic variation in the price experienced by a heroin user over time that occurs in markets for illegal drugs. The second strategy exploits the experimentally-induced variation in price experienced by a heroin user across experimental scenarios. Both empirical strategies result in the estimate that the conditional price elasticity of demand for heroin is approximately −0.80. PMID:25702687

Integrative review of implementation strategies for translation of research-based evidence by nurses.

Science.gov (United States)

Wuchner, Staci S

2014-01-01

The purpose of this review was to synthesize and critique experimental and/or quasi-experimental research that has evaluated implementation strategies for translation of research-based evidence into nursing practice. Successfully implementing evidence-based research can improve patient outcomes. Identifying successful implementation strategies is imperative to move research-based evidence into practice. As implementation science gains popularity, it is imperative to understand the strategies that most effectively translate research-based evidence into practice. The review used the CINAHL and MEDLINE (Ovid) databases. Articles were included if they were experimental and/or quasi-experimental research designs, were written in English, and measured nursing compliance to translation of research-based evidence. An independent review was performed to select and critique the included articles. A wide array of interventions were completed, including visual cues, audit and feedback, educational meetings and materials, reminders, outreach, and leadership involvement. Because of the complex multimodal nature of the interventions and the variety of research topics, comparison across interventions was difficult. Many difficulties exist in determining what implementation strategies are most effective for translation of research-based evidence into practice by nurses. With these limited findings, further research is warranted to determine which implementation strategies most successfully translate research-based evidence into practice.

DEVELOPING MEASURES TO IMPROVE STRENGTH INDICES OF SUPPORTING STRUCTURES FOR HEAD CARS OF DIESEL TRAINS DR1A ON THE BASIS OF EXPERIMENTAL-AND-THEORETICAL WORKS

Directory of Open Access Journals (Sweden)

O. M. Bondarev

2014-11-01

Full Text Available Purpose. The objective is to determine the stress-strain state of supporting structures of the head car body and the traction transmission unit, which can be created in the operation of emergency situations, and to develop the measures aimed at improving the stress-strain state of these elements. Methodology. In order to achieve this objective, in performing the work an experimental determination of efforts and stress levels in the most loaded elements of supporting structures as well as the traction transmission units was conducted; design models for the theoretical determination of stress and effort levels were developed. Findings. Based on the analysis of the calculation results the best options for the upgrades, which have been put into the basis of proposals aimed at improving the strength indices, were revealed. Originality. Based on the experimental and theoretical studies, scientific monitoring of development works on modernization and improvement of strength indices of supporting structures of head cars of diesel trains DR1A was performed. Practical value. The technical solution to the measures, which are to be carried out beyond the limits of assigned operation lifetime for diesel train of the series specified was developed and transferred to the Ukrzaliznytsia experts to introduce the proposed measures on improving the strength indices.

Useful model organisms, indicators, or both? Ground beetles (Coleoptera, Carabidae) reflecting environmental conditions.

Science.gov (United States)

Koivula, Matti J

2011-01-01

Classic studies have successfully linked single-species abundances, life-history traits, assemblage structures and biomass of carabid beetles to past and present, human-caused environmental impacts and variation in 'natural' conditions. This evidence has led many to suggest carabids to function as 'indicators' - a term that bears multiple meanings. Here, a conservation-oriented definition for an indicator is used, carabid indicator potential from seven views is evaluated, and ways to proceed in indicator research are discussed. (1) Carabid species richness poorly indicates the richness and abundance of other taxa, which underlines the importance of using multiple taxa in environmental assessments. The ability of assemblage indices and specialist or functional-group abundances to reflect rare species and habitats should be examined in detail. (2) Experimental evidence suggests that carabids may potentially serve as keystone indicators. (3) Carabids are sensitive to human-altered abiotic conditions, such as pesticide use in agro-ecosystems and heavy metal contamination of soils. Carabids might thus reflect ecological sustainability and 'ecosystem health'. (4) Carabid assemblages host abundant species characteristic of particular habitat types or successional stages, which makes them promising dominance indicators. (5) Carabids reflect variation in 'natural' conditions, but vegetation and structural features are more commonly adopted as condition indicators. Carabids nevertheless provide yet another, equally accurate, view on the structure of the environment. (6) Carabids may function as early-warning signalers, as suggested by recent studies linking climate and carabid distributions. (7) Carabids reflect natural and human-caused disturbances and management, but the usefulness of these responses for conservation purposes requires further research. In summary, European carabids appear useful model organisms and possibly indicators because they are diverse

Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago

Science.gov (United States)

Meltzer, David J.; Holliday, Vance T.; Cannon, Michael D.; Miller, D. Shane

2014-05-01

According to the Younger Dryas Impact Hypothesis (YDIH), ∼12,800 calendar years before present, North America experienced an extraterrestrial impact that triggered the Younger Dryas and devastated human populations and biotic communities on this continent and elsewhere. This supposed event is reportedly marked by multiple impact indicators, but critics have challenged this evidence, and considerable controversy now surrounds the YDIH. Proponents of the YDIH state that a key test of the hypothesis is whether those indicators are isochronous and securely dated to the Younger Dryas onset. They are not. We have examined the age basis of the supposed Younger Dryas boundary layer at the 29 sites and regions in North and South America, Europe, and the Middle East in which proponents report its occurrence. Several of the sites lack any age control, others have radiometric ages that are chronologically irrelevant, nearly a dozen have ages inferred by statistically and chronologically flawed age-depth interpolations, and in several the ages directly on the supposed impact layer are older or younger than ∼12,800 calendar years ago. Only 3 of the 29 sites fall within the temporal window of the YD onset as defined by YDIH proponents. The YDIH fails the critical chronological test of an isochronous event at the YD onset, which, coupled with the many published concerns about the extraterrestrial origin of the purported impact markers, renders the YDIH unsupported. There is no reason or compelling evidence to accept the claim that a cosmic impact occurred ∼12,800 y ago and caused the Younger Dryas.

The impact of feedback valence and communication style on intrinsic motivation in middle childhood: Experimental evidence and generalization across individual differences.

Science.gov (United States)

Mabbe, Elien; Soenens, Bart; De Muynck, Gert-Jan; Vansteenkiste, Maarten

2018-06-01

Prior research among adolescents and emerging adults has provided evidence for the beneficial effects of positive (relative to negative) feedback and an autonomy-supportive (relative to a controlling) communication style on students' intrinsic motivation. Unfortunately, similar experimental research in middle childhood is lacking. Moreover, little attention has been paid to the question of whether individual differences in personality and perceived parenting play a role in these effects. In the current experimental study (N = 110; M age  = 10.71 years), children completed puzzles at school under one of four experimental conditions, thereby crossing normative feedback valence (i.e., positive vs. negative) with communication style (i.e., autonomy supportive vs. controlling). Prior to the experiment, children filled out questionnaires tapping into the Big Five personality traits and into perceived maternal autonomy support and psychological control. After the experimental induction, children rated several motivational constructs (i.e., intrinsic motivation and need-based experiences). In addition, their voluntary behavioral persistence in a subsequent challenging puzzle task was recorded objectively. Providing positive normative feedback in an autonomy-supportive way yielded the most favorable motivational outcomes. Both feedback valence and communication style yielded an independent impact on children's experiences of competence and autonomy during task engagement, which in turn helped to explain children's elevated intrinsic motivation, as reflected by their perceived interest and behavioral persistence. A few effects were moderated by children's perceived parenting and personality traits, but the number of interactions was limited. The discussion focuses on the motivating role of positive normative feedback and an autonomy-supportive communication style for children. Copyright © 2018 Elsevier Inc. All rights reserved.

Experimental evaluation of solar still performance

Energy Technology Data Exchange (ETDEWEB)

Saif-ur-Rehman, M

1973-01-01

A method is described to measure various temperatures, insolation, and the distillate outputs from various stills simultaneously. The experimental results are used to study the thermodynamic behavior of solar still performance with the help of temperature profiles of saline water, underneath soil and glass. Effects of ageing on material deterioration and still output are discussed and in the light of the experimental evidence, recommendations are made for better still performance.

Improving evidence based practice in postgraduate nursing programs: A systematic review: Bridging the evidence practice gap (BRIDGE project).

Science.gov (United States)

Hickman, Louise D; DiGiacomo, Michelle; Phillips, Jane; Rao, Angela; Newton, Phillip J; Jackson, Debra; Ferguson, Caleb

2018-04-01

The nursing profession has a significant evidence to practice gap in an increasingly complex and dynamic health care environment. To evaluate effectiveness of teaching and learning strategies related to a capstone project within a Masters of Nursing program that encourage the development of evidence based practice capabilities. Systematic review that conforms to the PRISMA statement. Master's Nursing programs that include elements of a capstone project within a university setting. MEDLINE, CINAHL, Cochrane Database of Systematic Reviews, ERIC and PsycInfo were used to search for RCT's or quasi experimental studies conducted between 1979 and 9 June 2017, published in a peer reviewed journal in English. Of 1592 studies, no RCT's specifically addressed the development of evidence based practice capabilities within the university teaching environment. Five quasi-experimental studies integrated blended learning, guided design processes, small group work, role play and structured debate into Masters of Nursing research courses. All five studies demonstrated some improvements in evidence based practice skills and/or research knowledge translation, with three out of five studies demonstrating significant improvements. There is a paucity of empirical evidence supporting the best strategies to use in developing evidence based practice skills and/or research knowledge translation skills for Master's Nursing students. As a profession, nursing requires methodologically robust studies that are discipline specific to identify the best approaches for developing evidence-based practice skills and/or research knowledge translation skills within the university teaching environment. Provision of these strategies will enable the nursing profession to integrate the best empirical evidence into nursing practice. Copyright © 2018. Published by Elsevier Ltd.

Is the Urban Child Health Advantage Declining in Malawi?: Evidence from Demographic and Health Surveys and Multiple Indicator Cluster Surveys.

Science.gov (United States)

Lungu, Edgar Arnold; Biesma, Regien; Chirwa, Maureen; Darker, Catherine

2018-06-01

In many developing countries including Malawi, health indicators are on average better in urban than in rural areas. This phenomenon has largely prompted Governments to prioritize rural areas in programs to improve access to health services. However, considerable evidence has emerged that some population groups in urban areas may be facing worse health than rural areas and that the urban advantage may be waning in some contexts. We used a descriptive study undertaking a comparative analysis of 13 child health indicators between urban and rural areas using seven data points provided by nationally representative population based surveys-the Malawi Demographic and Health Surveys and Multiple Indicator Cluster Surveys. Rate differences between urban and rural values for selected child health indicators were calculated to denote whether urban-rural differentials showed a trend of declining urban advantage in Malawi. The results show that all forms of child mortality have significantly declined between 1992 and 2015/2016 reflecting successes in child health interventions. Rural-urban comparisons, using rate differences, largely indicate a picture of the narrowing gap between urban and rural areas albeit the extent and pattern vary among child health indicators. Of the 13 child health indicators, eight (neonatal mortality, infant mortality, under-five mortality rates, stunting rate, proportion of children treated for diarrhea and fever, proportion of children sleeping under insecticide-treated nets, and children fully immunized at 12 months) show clear patterns of a declining urban advantage particularly up to 2014. However, U-5MR shows reversal to a significant urban advantage in 2015/2016, and slight increases in urban advantage are noted for infant mortality rate, underweight, full childhood immunization, and stunting rate in 2015/2016. Our findings suggest the need to rethink the policy viewpoint of a disadvantaged rural and much better-off urban in child health

Fostering Early Math Comprehension: Experimental Evidence from Paraguay

Science.gov (United States)

Naslund-Hadley, Emma; Parker, Susan W.; Hernandez-Agramonte, Juan Manuel

2014-01-01

Research indicates that preschool children need to learn pre-math skills to build a foundation for primary- and secondary-level mathematics. This paper presents the results from the early stages of a pilot mathematics program implemented in Cordillera, Paraguay. In a context of significant gaps in teacher preparation and pedagogy, the program uses…

Experimental evidence of the thermal effect of lubricating oil sprayed in sliding-vane air compressors

Directory of Open Access Journals (Sweden)

Gianluca Valenti

2014-11-01

Full Text Available A way to increase the efficiency of positive-displacement air compressor is spraying the lube oil to exploit it not only as lubricating and sealing agent but also as thermal ballast. This work seeks the experimental evidence in sliding-vane compressors by measuring the air standard volume flow rate and the electrical power input of three diverse configurations. The first configuration, taken as the reference, employs a conventional injection system comprising calibrated straight orifices. The other two, referred to as advanced, adopt smaller orifices and pressure-swirl full-cone nozzles designed for the purpose; the third configuration utilizes a pump to boost the oil pressure. The laser imagining technique shows that the nozzles generate sprays that break-up within a short distance into spherical droplets, ligaments, ramifications and undefined structures. Tests on the packaged compressors reveal that the advanced configurations provide almost the same air flow rate while utilizing half of the oil because the sprays generate a good sealing. Moreover, the sprayed oil is acting as a thermal ballast because the electrical input is reduced by 3.5% and 3.0%, respectively, if the pump is present or not , while the specific energy requirement, accounting for the slightly reduced air flow, by 2.4% and 2.9%, respectively.

Experimental evidence of oxygen thermo-migration in PWR UO{sub 2} fuels during power ramps using in-situ oxido-reduction indicators

Energy Technology Data Exchange (ETDEWEB)

Riglet-Martial, Ch., E-mail: chantal.martial@cea.fr; Sercombe, J.; Lamontagne, J.; Noirot, J.; Roure, I.; Blay, T.; Desgranges, L.

2016-11-15

The present study describes the in-situ electrochemical modifications which affect irradiated PWR UO{sub 2} fuels in the course of a power ramp, by means of in-situ oxido-reduction indicators such as chromium or neo-formed chemical phases. It is shown that irradiated fuels (of nominal stoichiometry close to 2.000) under temperature gradient such as that occurring during high power transients are submitted to strong oxido-reduction perturbations, owing to radial migration of oxygen from the hot center to the cold periphery of the pellet. The oxygen redistribution, similar to that encountered in Sodium Fast Reactors fuels, induces a massive reduction/precipitation of the fission products Mo, Ru, Tc and Cr (if present) in the high temperature pellet section and the formation of highly oxidized neo-formed grey phases of U{sub 4}O{sub 9} type in its cold section, of lower temperature. The parameters governing the oxidation states of UO{sub 2} fuels under power ramps are finally debated from a cross-analysis of our results and other published information. The potential chemical benefits brought by oxido-reductive additives in UO{sub 2} fuel such as chromium oxide, in connection with their oxygen buffering properties, are discussed.

Useful model organisms, indicators, or both? Ground beetles (Coleoptera, Carabidae reflecting environmental conditions

Directory of Open Access Journals (Sweden)

Matti Koivula

2011-05-01

Full Text Available Classic studies have successfully linked single-species abundances, life-history traits, assemblage structures and biomass of carabid beetles to past and present, human-caused environmental impacts and variation in ‘natural’ conditions. This evidence has led many to suggest carabids to function as ‘indicators’ − a term that bears multiple meanings. Here, a conservation-oriented definition for an indicator is used, carabid indicator potential from seven views is evaluated, and ways to proceed in indicator research are discussed. (1 Carabid species richness poorly indicates the richness and abundance of other taxa, which underlines the importance of using multiple taxa in environmental assessments. The ability of assemblage indices and specialist or functional-group abundances to reflect rare species and habitats should be examined in detail. (2 Experimental evidence suggests that carabids may potentially serve as keystone indicators. (3 Carabids are sensitive to human-altered abiotic conditions, such as pesticide use in agro-ecosystems and heavy metal contamination of soils. Carabids might thus reflect ecological sustainability and ‘ecosystem health’. (4 Carabid assemblages host abundant species characteristic of particular habitat types or successional stages, which makes them promising dominance indicators. (5 Carabids reflect variation in ‘natural’ conditions, but vegetation and structural features are more commonly adopted as condition indicators. Carabids nevertheless provide yet another, equally accurate, view on the structure of the environment. (6 Carabids may function as early-warning signalers, as suggested by recent studies linking climate and carabid distributions. (7 Carabids reflect natural and human-caused disturbances and management, but the usefulness of these responses for conservation purposes requires further research. In summary, European carabids appear useful model organisms and possibly indicators because

Is the readmission rate a valid quality indicator? A review of the evidence

NARCIS (Netherlands)

Fischer, Claudia; Lingsma, Hester F.; Marang-van de Mheen, Perla J.; Kringos, Dionne S.; Klazinga, Niek S.; Steyerberg, Ewout W.

2014-01-01

Hospital readmission rates are increasingly used for both quality improvement and cost control. However, the validity of readmission rates as a measure of quality of hospital care is not evident. We aimed to give an overview of the different methodological aspects in the definition and measurement

Floristic indicators of tropical landuse systems: Evidence from mining areas in Southwestern Nigeria

Directory of Open Access Journals (Sweden)

Sehinde Akinbiola

2016-07-01

Full Text Available Most forests in the tropics have not only been reduced in size but have also experienced forest degradation. The delicate balance of the components of the forest ecosystem has been altered largely by the landuse systems which have resulted in the disappearance of some species and the introduction of new ones. In order to understand the influence of human disturbance caused by artisanal mining on plant biodiversity and the physical environment, this study assessed changes in vegetation characteristics using plant functional groups, such as invasive, pioneer and understory species. The study was conducted at two sites in two Southwestern states of Nigeria, Itagunmodi in Atakumosa West Local Government Area of Osun State and Olode in Oluyole Local Government Area of Oyo State. Complete enumerations of woody, non-woody and herbaceous plant species were carried out in 20 m by 20 m plots selected using stratified random sampling as representative of landuse classes: freshly mined (6 months and a control plot (secondary forest. The results showed that the control plot in Itagunmodi had undergone degradation as indicated by the presence of Alchornea laxiflora, Geophilia obvallata, Musa sapientum,Elaeis guineensis and Keetia hispida. However, if left undisturbed, it has the potential of regeneration back to its original state because of its woody tree species composition and lianas (Triclisia gilletii. In addition the forest soils in the mines had been exposed to direct insolation for a long period, and the soil structure and texture have been affected, consequently altering the viability of the seed bank. Poaceae and Papilionoideae were the most common in the freshly mined plots while invasive species were the most common in abandoned mined plots. In conclusion, the floristic composition in the mining sites has been altered and there was no clear evidence that regrowth would bring restoration of the lost ecosystem services.

Gender discrimination and social identity: experimental evidence from urban Pakistan

OpenAIRE

Delavande, Adeline; Zafar, Basit

2013-01-01

Gender discrimination in South Asia is a well-documented fact. However, gender is only one of an individual's many identities. This paper investigates how gender discrimination depends on the social identities of interacting parties. We use an experimental approach to identify gender discrimination by randomly matching 2,836 male and female students pursuing bachelor's-equivalent degrees in three different types of institutions - Madrassas (religious seminaries), Islamic universities, and lib...

Honest sexual signaling in turtles: experimental evidence of a trade-off between immune response and coloration in red-eared sliders Trachemys scripta elegans.

Science.gov (United States)

Ibáñez, Alejandro; Polo-Cavia, Nuria; López, Pilar; Martín, José

2014-10-01

Sexual signals can be evolutionarily stable if they are honest and condition dependent or costly to the signaler. One possible cost is the existence of a trade-off between maintaining the immune system and the elaboration of ornaments. This hypothesis has been experimentally tested in some groups of animals but not in others such as turtles. We experimentally challenged the immune system of female red-eared sliders Trachemys scripta elegans, with a bacterial antigen (lipopolysaccharide (LPS)) without pathogenic effects to explore whether the immune activation affected visual colorful ornaments of the head. The LPS injection altered the reflectance patterns of color ornaments. In comparison to the control animals, the yellow chin stripes of injected animals exhibited (1) reduced brightness, (2) lower long wavelength (>470 nm) reflectance, and (3) lower values for carotenoid chroma. The postorbital patches of injected individuals also showed reduced very long wavelength (>570 nm) reflectance but did not change in carotenoid chroma. Thus, experimental turtles showed darker and less "yellowish" chin stripes and less "reddish" postorbital patches at the end of the experiment, whereas control turtles did not change their coloration. This is the first experimental evidence supporting the existence of a trade-off between the immune system and the expression of visual ornaments in turtles. We suggest that this trade-off may allow turtles to honestly signal individual quality via characteristics of coloration, which may have an important role in intersexual selection processes.

Honest sexual signaling in turtles: experimental evidence of a trade-off between immune response and coloration in red-eared sliders Trachemys scripta elegans

Science.gov (United States)

Ibáñez, Alejandro; Polo-Cavia, Nuria; López, Pilar; Martín, José

2014-10-01

Sexual signals can be evolutionarily stable if they are honest and condition dependent or costly to the signaler. One possible cost is the existence of a trade-off between maintaining the immune system and the elaboration of ornaments. This hypothesis has been experimentally tested in some groups of animals but not in others such as turtles. We experimentally challenged the immune system of female red-eared sliders Trachemys scripta elegans, with a bacterial antigen (lipopolysaccharide (LPS)) without pathogenic effects to explore whether the immune activation affected visual colorful ornaments of the head. The LPS injection altered the reflectance patterns of color ornaments. In comparison to the control animals, the yellow chin stripes of injected animals exhibited (1) reduced brightness, (2) lower long wavelength (>470 nm) reflectance, and (3) lower values for carotenoid chroma. The postorbital patches of injected individuals also showed reduced very long wavelength (>570 nm) reflectance but did not change in carotenoid chroma. Thus, experimental turtles showed darker and less "yellowish" chin stripes and less "reddish" postorbital patches at the end of the experiment, whereas control turtles did not change their coloration. This is the first experimental evidence supporting the existence of a trade-off between the immune system and the expression of visual ornaments in turtles. We suggest that this trade-off may allow turtles to honestly signal individual quality via characteristics of coloration, which may have an important role in intersexual selection processes.

Constructing a New Theory from Old Ideas and New Evidence

Science.gov (United States)

Rhodes, Marjorie; Wellman, Henry

2013-01-01

A central tenet of constructivist models of conceptual development is that children's initial conceptual level constrains how they make sense of new evidence and thus whether exposure to evidence will prompt conceptual change. Yet little experimental evidence directly examines this claim for the case of sustained, fundamental conceptual…

Spontaneous Time Symmetry Breaking in System with Mixed Strategy Nash Equilibrium: Evidences in Experimental Economics Data

Science.gov (United States)

Wang, Zhijian; Xu, Bin; Zhejiang Collaboration

2011-03-01

In social science, laboratory experiment with human subjects' interaction is a standard test-bed for studying social processes in micro level. Usually, as in physics, the processes near equilibrium are suggested as stochastic processes with time-reversal symmetry (TRS). To the best of our knowledge, near equilibrium, the breaking time symmetry, as well as the existence of robust time anti-symmetry processes, has not been reported clearly in experimental economics till now. By employing Markov transition method to analysis the data from human subject 2x2 Games with wide parameters and mixed Nash equilibrium, we study the time symmetry of the social interaction process near Nash equilibrium. We find that, the time symmetry is broken, and there exists a robust time anti-symmetry processes. We also report the weight of the time anti-symmetry processes in the total processes of each the games. Evidences in laboratory marketing experiments, at the same time, are provided as one-dimension cases. In these cases, time anti-symmetry cycles can also be captured. The proposition of time anti-symmetry processes is small, but the cycles are distinguishable.

Exposure affects the risk of an owl being mobbed - experimental evidence

DEFF Research Database (Denmark)

Hendrichsen, Ditte Katrine; Christiansen, Peter; Nielsen, Elsemarie K.

2006-01-01

Mobbing is a widespread anti-predator strategy in birds, and predators are generally expected to avoid mobbing. For example, observational studies suggest that the cryptic roosting behaviour of nocturnal predators, such as many owls, may be a strategy to limit mobbing. In this paper, we present...... the results of the first experimental study investigating to what degree roost exposure influences the risk of being mobbed, and the intensity of a mobbing incidence once initiated. To determine these factors, we used an experimental setup with taxidermic mounts of tawny owls Strix aluco in Grib Skov forest......, Denmark. The risk of an owl being mobbed during a 50 min morning survey period increased with the exposure of its roosting position, from 24% when hidden to 85% when openly exposed. The corresponding increase in the afternoon was from 6% to 36%. This suggests that an owl may minimize the mobbing rate...

Experimental evidence for adaptive personalities in a wild passerine bird

Science.gov (United States)

Nicolaus, Marion; Tinbergen, Joost M.; Bouwman, Karen M.; Michler, Stephanie P. M.; Ubels, Richard; Both, Christiaan; Kempenaers, Bart; Dingemanse, Niels J.

2012-01-01

Individuals of the same species differ consistently in risky actions. Such ‘animal personality’ variation is intriguing because behavioural flexibility is often assumed to be the norm. Recent theory predicts that between-individual differences in propensity to take risks should evolve if individuals differ in future fitness expectations: individuals with high long-term fitness expectations (i.e. that have much to lose) should behave consistently more cautious than individuals with lower expectations. Consequently, any manipulation of future fitness expectations should result in within-individual changes in risky behaviour in the direction predicted by this adaptive theory. We tested this prediction and confirmed experimentally that individuals indeed adjust their ‘exploration behaviour’, a proxy for risk-taking behaviour, to their future fitness expectations. We show for wild great tits (Parus major) that individuals with experimentally decreased survival probability become faster explorers (i.e. increase risk-taking behaviour) compared to individuals with increased survival probability. We also show, using quantitative genetics approaches, that non-genetic effects (i.e. permanent environment effects) underpin adaptive personality variation in this species. This study thereby confirms a key prediction of adaptive personality theory based on life-history trade-offs, and implies that selection may indeed favour the evolution of personalities in situations where individuals differ in future fitness expectations. PMID:23097506

Judging the Probability of Hypotheses Versus the Impact of Evidence: Which Form of Inductive Inference Is More Accurate and Time-Consistent?

Science.gov (United States)

Tentori, Katya; Chater, Nick; Crupi, Vincenzo

2016-04-01

Inductive reasoning requires exploiting links between evidence and hypotheses. This can be done focusing either on the posterior probability of the hypothesis when updated on the new evidence or on the impact of the new evidence on the credibility of the hypothesis. But are these two cognitive representations equally reliable? This study investigates this question by comparing probability and impact judgments on the same experimental materials. The results indicate that impact judgments are more consistent in time and more accurate than probability judgments. Impact judgments also predict the direction of errors in probability judgments. These findings suggest that human inductive reasoning relies more on estimating evidential impact than on posterior probability. Copyright © 2015 Cognitive Science Society, Inc.

Disclosing doubtful indications for emergency cesarean sections in rural hospitals in Tanzania

DEFF Research Database (Denmark)

Maaløe, Nanna; Bygbjerg, Ib Christian; Onesmo, Rwakyendela

2012-01-01

To investigate in depth to what extent indications for emergency cesarean sections followed evidence-based audit criteria for realistic best practice.......To investigate in depth to what extent indications for emergency cesarean sections followed evidence-based audit criteria for realistic best practice....

Further evidence for magnetic charge from meson spectroscopy

International Nuclear Information System (INIS)

Akers, D.

1987-01-01

Recently evidence was presented for the existence of magnetic charge from Zeeman splitting in meson states. The model by Akers predicted the existence of a new eta meson at 1814 MeV with I/sup G/ (J/sup PC/) = O + (O -+ ). Experimental evidence for this new meson is cited and discussed

Monitoring healthy and disturbed sleep through smartphone applications: a review of experimental evidence.

Science.gov (United States)

Fino, Edita; Mazzetti, Michela

2018-04-23

Smartphone applications are considered as the prime candidate for the purposes of large-scale, low-cost and long-term sleep monitoring. How reliable and scientifically grounded is smartphone-based assessment of healthy and disturbed sleep remains a key issue in this direction. Here we offer a review of validation studies of sleep applications to the aim of providing some guidance in terms of their reliability to assess sleep in healthy and clinical populations, and stimulating further examination of their potential for clinical use and improved sleep hygiene. Electronic literature review was conducted on Pubmed. Eleven validation studies published since 2012 were identified, evaluating smartphone applications' performance compared to standard methods of sleep assessment in healthy and clinical samples. Studies with healthy populations show that most sleep applications meet or exceed accuracy levels of wrist-based actigraphy in sleep-wake cycle discrimination, whereas performance levels drop in individuals with low sleep efficiency (SE) and in clinical populations, mirroring actigraphy results. Poor correlation with polysomnography (PSG) sleep sub-stages is reported by most accelerometer-based apps. However, multiple parameter-based applications (i.e., EarlySense, SleepAp) showed good capability in detection of sleep-wake stages and sleep-related breathing disorders (SRBD) like obstructive sleep apnea (OSA) respectively with values similar to PSG. While the reviewed evidence suggests a potential role of smartphone sleep applications in pre-screening of SRBD, more experimental studies are warranted to assess their reliability in sleep-wake detection particularly. Apps' utility in post treatment follow-up at home or as an adjunct to the sleep diary in clinical setting is also stressed.

Probability Judgements in Multi-Stage Problems : Experimental Evidence of Systematic Biases

NARCIS (Netherlands)

Gneezy, U.

1996-01-01

We report empirical evidence that in problems of random walk with positive drift, bounded rationality leads individuals to under-estimate the probability of success in the long run.In particular, individuals who were given the stage by stage probability distribution failed to aggregate this

Experimental evidence and modelling of drought induced alternative stable soil moisture states

Science.gov (United States)

Robinson, David; Jones, Scott; Lebron, Inma; Reinsch, Sabine; Dominguez, Maria; Smith, Andrew; Marshal, Miles; Emmett, Bridget

2017-04-01

The theory of alternative stable states in ecosystems is well established in ecology; however, evidence from manipulation experiments supporting the theory is limited. Developing the evidence base is important because it has profound implications for ecosystem management. Here we show evidence of the existence of alternative stable soil moisture states induced by drought in an upland wet heath. We used a long-term (15 yrs) climate change manipulation experiment with moderate sustained drought, which reduced the ability of the soil to retain soil moisture by degrading the soil structure, reducing moisture retention. Moreover, natural intense droughts superimposed themselves on the experiment, causing an unexpected additional alternative soil moisture state to develop, both for the drought manipulation and control plots; this impaired the soil from rewetting in winter. Our results show the coexistence of three stable states. Using modelling with the Hydrus 1D software package we are able to show the circumstances under which shifts in soil moisture states are likely to occur. Given the new understanding it presents a challenge of how to incorporate feedbacks, particularly related to soil structure, into soil flow and transport models?

Experimental evidence for importance of Hund's exchange interaction for incoherence of charge carriers in iron-based superconductors

Science.gov (United States)

Fink, J.; Rienks, E. D. L.; Thirupathaiah, S.; Nayak, J.; van Roekeghem, A.; Biermann, S.; Wolf, T.; Adelmann, P.; Jeevan, H. S.; Gegenwart, P.; Wurmehl, S.; Felser, C.; Büchner, B.

2017-04-01

Angle-resolved photoemission spectroscopy is used to study the scattering rates of charge carriers from the hole pockets near Γ in the iron-based high-Tc hole-doped superconductors KxBa1 -xFe2As2 , x =0.4 , and KxEu1 -xFe2As2 , x =0.55 , and the electron-doped compound Ba (Fe1-xCox) 2As2 , x =0.075 . The scattering rate for any given band is found to depend linearly on the energy, indicating a non-Fermi-liquid regime. The scattering rates in the hole-doped compound are considerably higher than those in the electron-doped compounds. In the hole-doped systems the scattering rate of the charge carriers of the inner hole pocket is about three times higher than the binding energy, indicating that the spectral weight is heavily incoherent. The strength of the scattering rates and the difference between electron- and hole-doped compounds signals the importance of Hund's exchange coupling for correlation effects in these iron-based high-Tc superconductors. The experimental results are in qualitative agreement with theoretical calculations in the framework of combined density functional dynamical mean-field theory.

Ethnic and gender discrimination in recruitment: experimental evidence from Finland

OpenAIRE

Liebkind, Karmela; Larja, Lisa; Brylka, Asteria Anna

2016-01-01

We ask (1) how the position of an ethnic (majority or minority) group in the local ethnic hierarchy affects the amount of recruitment discrimination faced by applicants from that group, and (2) whether gender discrimination is dependent on occupational gender stereotypes in the same way among ethnic majority and minority applicants. We use the situation testing method for the first time in Finland: In an experimental study (Study 1), 103 dentistry students made recruitment decisions based on ...

Experimental evidence of a symbiosis between red-cockaded woodpeckers and fungi

Science.gov (United States)

Michelle A. Jusino; Daniel L. Lindner; Mark T. Banik; Kevin R. Rose; Jeffrey R. Walters

2016-01-01

Primary cavity excavators, such as woodpeckers, are ecosystem engineers in many systems. Associations between cavity excavators and fungi have long been hypothesized to facilitate cavity excavation, but these relationships have not been experimentally verified. Fungi may help excavators by softening wood, while excavators may facilitate fungal dispersal. Here we...

Which experimental model can sensitively indicate brain death by functional near-infrared spectroscopy?

Science.gov (United States)

Pan, Boan; Liu, Weichao; Fang, Xiang; Huang, Xiaobo; Li, Ting

2018-02-01

Brain death is defined as permanent loss of the brain functions. The evaluation of it has many meanings, such as the relief of organ transplantation stress and family burden. However, it is hard to be judged precisely. The standard clinical tests are expensive, time consuming and even dangerous, and some auxiliary methods have limitations. Functional near infrared spectroscopy (fNIRS), monitoring cerebral hemodynamic responses noninvasively, evaluate brain death in some papers published, but there is no discussion about which experimental mode can monitor brain death patient more sensitively. Here, we attempt to use our fNIRS to evaluate brain death and find which experimental mode is effective. In order to discuss the problem, we detected eleven brain death patients and twenty normal patients under natural state. They were provided different fraction of inspiration O2 (FIO2) in different phase. We found that the ratio of Δ[HbO2] (the concentration changes in oxyhemoglobin) to Δ[Hb] (the concentration changes in deoxyhemoglobin) in brain death patients is significantly higher than normal patients in FIO2 experiment. Combined with the data analysis result, restore oxygen change process and low-high-low paradigm is more sensitively.

Modulation of Antioxidant Enzymatic Activities by Certain Antiepileptic Drugs (Valproic Acid, Oxcarbazepine, and Topiramate): Evidence in Humans and Experimental Models

Science.gov (United States)

Cárdenas-Rodríguez, Noemí; Coballase-Urrutia, Elvia; Rivera-Espinosa, Liliana; Romero-Toledo, Arantxa; Sampieri, Aristides III; Ortega-Cuellar, Daniel; Montesinos-Correa, Hortencia; Floriano-Sánchez, Esaú; Carmona-Aparicio, Liliana

2013-01-01

It is estimated that at least 100 million people worldwide will suffer from epilepsy at some point in their lives. This neurological disorder induces brain death due to the excessive liberation of glutamate, which activates the postsynaptic N-methyl-D-aspartic acid (NMDA) receptors, which in turn cause the reuptake of intracellular calcium (excitotoxicity). This excitotoxicity elicits a series of events leading to nitric oxide synthase (NOS) activation and the generation of reactive oxygen species (ROS). Several studies in experimental models and in humans have demonstrated that certain antiepileptic drugs (AEDs) exhibit antioxidant effects by modulating the activity of various enzymes associated with this type of stress. Considering the above-mentioned data, we aimed to compile evidence elucidating how AEDs such as valproic acid (VPA), oxcarbazepine (OXC), and topiramate (TPM) modulate oxidative stress. PMID:24454986

Identifying marine pelagic ecosystem management objectives and indicators

DEFF Research Database (Denmark)

Trenkel, Verena M.; Hintzen, Niels T.; Farnsworth, Keith D.

2015-01-01

. Overall 26 objectives were proposed, with 58% agreement in proposed objectives between two workshops. Based on published evidence for pressure-state links, examples of operational objectives and suitable indicators for each of the 26 objectives were then selected. It is argued that given the strong......International policy frameworks such as the Common Fisheries Policy and the European Marine Strategy Framework Directive define high-level strategic goals for marine ecosystems. Strategic goals are addressed via general and operational management objectives. To add credibility and legitimacy...... scale in some cases. In the evidence-based approach used in this study, the selection of species or region specific operational objectives and indicators was based on demonstrated pressure-state links. Hence observed changes in indicators can reliably inform on appropriate management measures. (C) 2015...

Empirical Evidence on Student-t Log-Returns of Diversified World Stock Indices

OpenAIRE

Eckhard Platen; Renata Rendek

2007-01-01

The aim of this paper is to document some empirical facts related to log-returns of diversified world stock indices when these are denominated in different currencies. Motivated by earlier results, we have obtained the estimated distribution of log-returns for a range of world stock indices over long observation periods. We expand previous studies by applying the maximum likelihood ratio test to the large class of generalized hyperbolic distributions, and investigate the log-returns of a vari...

Quasi experimental designs in pharmacist intervention research.

Science.gov (United States)

Krass, Ines

2016-06-01

Background In the field of pharmacist intervention research it is often difficult to conform to the rigorous requirements of the "true experimental" models, especially the requirement of randomization. When randomization is not feasible, a practice based researcher can choose from a range of "quasi-experimental designs" i.e., non-randomised and at time non controlled. Objective The aim of this article was to provide an overview of quasi-experimental designs, discuss their strengths and weaknesses and to investigate their application in pharmacist intervention research over the previous decade. Results In the literature quasi experimental studies may be classified into five broad categories: quasi-experimental design without control groups; quasi-experimental design that use control groups with no pre-test; quasi-experimental design that use control groups and pre-tests; interrupted time series and stepped wedge designs. Quasi-experimental study design has consistently featured in the evolution of pharmacist intervention research. The most commonly applied of all quasi experimental designs in the practice based research literature are the one group pre-post-test design and the non-equivalent control group design i.e., (untreated control group with dependent pre-tests and post-tests) and have been used to test the impact of pharmacist interventions in general medications management as well as in specific disease states. Conclusion Quasi experimental studies have a role to play as proof of concept, in the pilot phases of interventions when testing different intervention components, especially in complex interventions. They serve to develop an understanding of possible intervention effects: while in isolation they yield weak evidence of clinical efficacy, taken collectively, they help build a body of evidence in support of the value of pharmacist interventions across different practice settings and countries. However, when a traditional RCT is not feasible for

Experimental animal modelling for TB vaccine development

Directory of Open Access Journals (Sweden)

Pere-Joan Cardona

2017-03-01

Full Text Available Research for a novel vaccine to prevent tuberculosis is an urgent medical need. The current vaccine, BCG, has demonstrated a non-homogenous efficacy in humans, but still is the gold standard to be improved upon. In general, the main indicator for testing the potency of new candidates in animal models is the reduction of the bacillary load in the lungs at the acute phase of the infection. Usually, this reduction is similar to that induced by BCG, although in some cases a weak but significant improvement can be detected, but none of candidates are able to prevent establishment of infection. The main characteristics of several laboratory animals are reviewed, reflecting that none are able to simulate the whole characteristics of human tuberculosis. As, so far, no surrogate of protection has been found, it is important to test new candidates in several models in order to generate convincing evidence of efficacy that might be better than that of BCG in humans. It is also important to investigate the use of “in silico” and “ex vivo” models to better understand experimental data and also to try to replace, or at least reduce and refine experimental models in animals.

Empirical evidence of bias in the design of experimental stroke studies - A metaepidemiologic approach

NARCIS (Netherlands)

Crossley, Nicolas A.; Sena, Emily; Goehler, Jos; Horn, Jannekke; van der Worp, Bart; Bath, Philip M. W.; Macleod, Malcolm; Dirnagl, Ulrich

2008-01-01

Background and Purpose - At least part of the failure in the transition from experimental to clinical studies in stroke has been attributed to the imprecision introduced by problems in the design of experimental stroke studies. Using a metaepidemiologic approach, we addressed the effect of

Experimental Learning in Nursing Literature Education

Directory of Open Access Journals (Sweden)

Eskandar Fathiazar

2015-08-01

Full Text Available ​Experimental learning is a type of discovery learning. This method of learning appears to be suitable for nursing education, but there is not enough evidence about it. As a result, in this non-systematic review article, after explaining experimental learning, its application in nursing will be presented based on literature review and with functional examples. According to the results, in this kind of learning, students practice with experimental cases and learn by failure in. Participants should have the main role and teachers act as mentors or learning facilitators. According to the literature, it seems useful to use this new method in nursing education.

Sex-specific consequences of experimental cortisol elevation in pre-reproductive wild largemouth bass.

Science.gov (United States)

O'Connor, Constance M; Nannini, Michael; Wahl, David H; Wilson, Samantha M; Gilmour, Kathleen M; Cooke, Steven J

2013-01-01

Experimental implants were used to investigate the effect of elevated cortisol (the primary stress hormone in teleost fish) on energetic and physiological condition prior to reproduction in male and female largemouth bass (Micropterus salmoides). Fish were wild-caught from lakes in Illinois, and held in experimental ponds for the duration of the study. Between 9 and 13 days after cortisol treatment, and immediately prior to the start of the reproductive period, treated and control animals were sampled. Females exhibited lower muscle lipid content, lower liver glycogen content, and higher hepatosomatic indices than males, regardless of treatment. Also, cortisol-treated females had higher hepatosomatic indices and lower final mass than control females, whereas males showed no differences between treatment groups. Finally, cortisol-treated females had higher gonadal cortisol concentrations than control females. In general, we found evidence of reduced energetic stores in female fish relative to male fish, likely due to timing differences in the allocation of resources during reproduction between males and females. Perhaps driven by the difference in energetic reserves, our data further suggest that females are more sensitive than males to elevated cortisol during the period immediately prior to reproduction. Copyright © 2012 Wiley Periodicals, Inc.

Reproductive interference and fecundity affect competitive interactions of sibling species with low mating barriers: experimental and theoretical evidence.

Science.gov (United States)

Gebiola, M; Kelly, S E; Velten, L; Zug, R; Hammerstein, P; Giorgini, M; Hunter, M S

2017-12-01

When allopatric species with incomplete prezygotic isolation come into secondary contact, the outcome of their interaction is not easily predicted. The parasitoid wasp Encarsia suzannae (iES), infected by Cardinium inducing cytoplasmic incompatibility (CI), and its sibling species E. gennaroi (EG), not infected by bacterial endosymbionts, may have diverged because of the complementary action of CI and asymmetric hybrid incompatibilities. Whereas postzygotic isolation is now complete because of sterility of F1 hybrid progeny, prezygotic isolation is still incipient. We set up laboratory population cage experiments to evaluate the outcome of the interaction between ES and EG in two pairwise combinations: iES vs EG and cured ES (cES, where Cardinium was removed with antibiotics) vs EG. We also built a theoretical model aimed at exploring the role of life-history differences and asymmetric mating on competitive outcomes. In three of four cages in each treatment, ES dominated the interaction. We found evidence for reproductive interference, driven by asymmetric mating preferences, that gave a competitive edge to ES, the species that better discriminated against heterospecifics. However, we did not find the fecundity cost previously shown to be associated with Cardinium infection in iES. The model largely supported the experimental results. The finding of only a slight competitive edge of ES over EG in population cages suggests that in a more heterogeneous environment the species could coexist. This is supported by evidence that the two species coexist in sympatry, where preliminary data suggest reproductive character displacement may have reinforced postzygotic isolation.

What Behaviors are Disapproved? Experimental Evidence from Five Dictator Games

Directory of Open Access Journals (Sweden)

Marc Vorsatz

2012-04-01

Full Text Available The literature on social norms has often stressed that social disapproval is crucial to foster compliance with norms and promote fair and cooperative behavior. With this in mind, we explore the disapproval of allocation decisions using experimental data from five dictator games with a feedback stage. Our data suggests that subjects are heterogeneous in their disapproval patterns, distinguishing two main groups: (1 Subjects who only disapprove choices that harm them, and (2 subjects who disapprove socially inefficient choices.

Concussion guidelines step 1: systematic review of prevalent indicators.

Science.gov (United States)

Carney, Nancy; Ghajar, Jamshid; Jagoda, Andy; Bedrick, Steven; Davis-OʼReilly, Cynthia; du Coudray, Hugo; Hack, Dallas; Helfand, Nora; Huddleston, Amy; Nettleton, Tracie; Riggio, Silvana

2014-09-01

Currently, there is no evidence-based definition for concussion that is being uniformly applied in clinical and research settings. To conduct a systematic review of the highest-quality literature about concussion and to assemble evidence about the prevalence and associations of key indicators of concussion. The goal was to establish an evidence-based foundation from which to derive, in future work, a definition, diagnostic criteria, and prognostic indicators for concussion. Key questions were developed, and an electronic literature search from 1980 to 2012 was conducted to acquire evidence about the prevalence of and associations among signs, symptoms, and neurologic and cognitive deficits in samples of individuals exposed to potential concussive events. Included studies were assessed for potential for bias and confound and rated as high, medium, or low potential for bias and confound. Those rated as high were excluded from the analysis. Studies were further triaged on the basis of whether the definition of a case of concussion was exclusive or inclusive; only those with wide, inclusive case definitions were used in the analysis. Finally, only studies reporting data collected at fixed time points were used. For a study to be included in the conclusions, it was required that the presence of any particular sign, symptom, or deficit be reported in at least 2 independent samples. From 5437 abstracts, 1362 full-text publications were reviewed, of which 231 studies were included in the final library. Twenty-six met all criteria required to be used in the analysis, and of those, 11 independent samples from 8 publications directly contributed data to conclusions. Prevalent and consistent indicators of concussion are (1) observed and documented disorientation or confusion immediately after the event, (2) impaired balance within 1 day after injury, (3) slower reaction time within 2 days after injury, and/or (4) impaired verbal learning and memory within 2 days after injury

Glazed clay pottery and lead exposure in Mexico: Current experimental evidence.

Science.gov (United States)

Diaz-Ruiz, Araceli; Tristán-López, Luis Antonio; Medrano-Gómez, Karen Itzel; Torres-Domínguez, Juan Alejandro; Ríos, Camilo; Montes, Sergio

2017-11-01

Lead exposure remains a significant environmental problem; lead is neurotoxic, especially in developing humans. In Mexico, lead in human blood is still a concern. Historically, much of the lead exposure is attributed to the use of handcrafted clay pottery for cooking, storing and serving food. However, experimental cause-and-effect demonstration is lacking. The present study explores this issue with a prospective experimental approach. We used handcrafted clay containers to prepare and store lemonade, which was supplied as drinking water to pregnant rats throughout the gestational period. We found that clay pots, jars, and mugs leached on average 200 µg/l lead, and exposure to the lemonade resulted in 2.5 µg/dl of lead in the pregnant rats' blood. Neonates also showed increased lead content in the hippocampus and cerebellum. Caspase-3 activity was found to be statistically increased in the hippocampus in prenatally exposed neonates, suggesting increased apoptosis in that brain region. Glazed ceramics are still an important source of lead exposure in Mexico, and our results confirm that pregnancy is a vulnerable period for brain development.

Experimental insights into angiosperm origins.

Science.gov (United States)

Lomax, Barry; Lee, Alex; Smilie, Ian; Knight, Charles; Upchurch, Garland

2017-04-01

The angiosperms occupy almost every habitat type on Earth and comprise nearly 90% of extant plant species. Yet this ascendency is a relatively recent (geological) phenomenon. Palaeobotanical evidence indicates a likely first occurrence in the Early Cretaceous followed by a relatively rapid increase in diversity with their rise to dominance marking the onset of modern world. Understanding this diversification event has been a key research question since Darwin commented on this "abominable mystery", and it remains one of the most significant unanswered questions in plant biology. Sequencing work shows that the diversification and radiation was accompanied by successive whole genome duplication (WGD) events. Furthermore proxy data and predictions from long-term carbon cycle models indicate that the angiosperm diversification was accompanied by a decline in atmospheric CO2. These observation raise the intriguing possibility that declining atmospheric CO2 concentration and capacity to undergo polyploidy could have given angiosperms a competitive advantage when compared to other plant groups. Using comparative ecophysiology we set out to test the effects of declining atmospheric CO2 by growing a six species (Ranunculus acris and Polypodium vulgare, chosen to represent Cretaceous understorey angiosperms and pteridophytes respectively. Liquidambar styraciflua and Laurus nobilis represented canopy angiosperms and Ginkgo biloba and Metasequoia glyptostroboides canopy gymnosperms) in controlled conditions across a CO2 gradient (2000, 1200, 800 and 400 ppm) to simulate Cretaceous CO2decline. To test for WGDs we use the relationship between guard cell size and genome size to reconstruct angiosperm genome size as they radiated. Analysis of our fossil dataset shows that earliest angiosperms had a small genome size. Our experimental work shows that angiosperms have a greater capacity for acclimation suggesting that declining CO2 could have acted as a trigger for the angiosperm

Experimental evidence for self-sealing of fractures in argillites

International Nuclear Information System (INIS)

Zhang, Chun-Liang

2010-01-01

Document available in extended abstract form only. In argillaceous rocks, self-sealing of fractures generated by the excavation of underground repositories can be expected due to combined impact of rock compression, backfill resistance, and clay swelling during the post-closure phase. The sealing process is determined by the deformability and swelling capacity of the host rock and the backfill as well as by the boundary conditions. As a crucial factor for the long-term safety of repositories, the sealing behaviour of fractures in argillites has been experimentally investigated by GRS on the Callovo-Oxfordian argillite (COX) and the Opalinus clay (OPA) under relevant repository conditions. Comprehensive laboratory tests were carried out on artificially-fractured samples of different sizes (diameter/length = 50/50 - 280/600 mm) and shapes (cylinder and hollow cylinder) under various confining stresses, fluid pressures, and temperatures. The sealing of fractures was detected by measurement of deformation, permeability and wave velocity variations. Following previous studies in which the sealing of fractured samples was determined by gas flow at ambient temperature, additional tests were performed by flowing synthetic pore water through fractures under different confining stresses and at elevated temperatures. Typical results of the tests are presented in this paper. Current results of the ongoing long-term permeability measurements on fractured COX and OPA samples (D/L = 50/50 mm) are summarized, some of which were pre-heated up to high temperatures of 50, 100 and 150 deg. C. In those tests, synthetic pore water was flowed through at injection pressure of 1 MPa, confining stresses of 2 to 3 MPa, and elevated temperatures from 20 to 90 deg. C. All fractured samples showed the same high initial gas permeability of 3.10 -12 m 2 . As the water was injected, the permeability dropped down by three to five orders of magnitude to 10 -15 to 10 -18 m 2 , depending on the

Bias against foreign-born or foreign-trained doctors: experimental evidence.

Science.gov (United States)

Louis, Winnifred R; Lalonde, Richard N; Esses, Victoria M

2010-12-01

Bias against foreign-born or -trained medical students and doctors is not well understood, despite its documented impact on recruitment, integration and retention. This research experimentally examines the interaction of location of medical education and nationality in evaluations of doctors' competence and trustworthiness. A convenience sample of prospective patients evaluated fictitious candidates for a position as a doctor in community practice at a new local health clinic. All applicants were described as having the same personality profile, legal qualifications to practise, a multi-degree education and relevant work experience. The location of medical education (the candidate's home country or the UK) and national background (Australia or Pakistan) of the applicants were independently experimentally manipulated. Consistent with previous research on skills discounting and bias, foreign-born candidates were evaluated less favourably than native-born candidates, despite their comparable education level, work experience and personality. However, overseas medical education obtained in the First World both boosted evaluations (of competence and trustworthiness) and attenuated bias based on nationality. The present findings demonstrate the selective discounting of foreign-born doctors' credentials. The data show an interaction of location of medical education and birth nationality in bias against foreign doctors. On an applied level, the data document that the benefits of medical education obtained in the First World can extend beyond its direct outcomes (high-quality training and institutional recognition) to the indirect benefit of the attenuation of patient bias based on nationality. © Blackwell Publishing Ltd 2010.

Cerebral microcirculation during experimental normovolaemic anaemia

Directory of Open Access Journals (Sweden)

Judith eBellapart

2016-02-01

Full Text Available Anaemia is accepted amongst critically ill patients as an alternative to elective blood transfusion. This practice has been extrapolated to head injury patients with only one study comparing the effects of mild anaemia on neurological outcome. There are no studies quantifying microcirculation during anaemia. Experimental studies suggest that anaemia leads to cerebral hypoxia and increased rates of infarction, but the lack of clinical equipoise when testing the cerebral effects of transfusion amongst critically injured patients, supports the need of experimental studies. The aim of this study was to quantify cerebral microcirculation and the potential presence of axonal damage in an experimental model exposed to normovolaemic anaemia, with the intention of describing possible limitations within management practices in critically ill patients. Under non-recovered anaesthesia, six Merino sheep were instrumented using an intracardiac transeptal catheter to inject coded microspheres into the left atrium to ensure systemic and non-chaotic distribution. Cytometric analyses quantified cerebral microcirculation at specific regions of the brain. Amyloid precursor protein staining was used as an indicator of axonal damage. Animals were exposed to normovolaemic anaemia by blood extractions from the indwelling arterial catheter with simultaneous fluid replacement through a venous central catheter. Simultaneous data recording from cerebral tissue oxygenation, intracranial pressure and cardiac output was monitored. A regression model was used to examine the effects of anaemia on microcirculation with a mixed model to control for repeated measures. Homogeneous and normal cerebral microcirculation with no evidence of axonal damage was present in all cerebral regions, with no temporal variability, concluding that acute normovolaemic anaemia does not result in short term effects on cerebral microcirculation in the ovine brain.

geo-scientific indicators for safety

International Nuclear Information System (INIS)

Andersson, J.; Bruno, G.; Deguchi, A.; Fein, E.; Larue, P.J.; Lei, S.; Leung, H.; Norris, S.; Violette, S.; Wollrath, J.

2007-01-01

Working Group A was continuation of Working Group B of AMIGO-1, but participants explored more deeply the issues surrounding geo-scientific indicators for safety. The following outcomes were expected. - List different geo-scientific arguments or indicators for safety (with motivation) for various host rocks and sites. Consider dividing the arguments into those that support isolation or retention and discuss their applicability for different time frames. - What actual measurable field evidence supports these arguments/indicators? - What kind of field evidence would go counter to these safety arguments? - What key messages are the most promising in terms of scientific credibility to contribute to the safety case? Possibly examine the same message but in terms of potential ease of communication. The session started with two introductory presentations: - Following the presentations, in discussion the Working Group listed: - Safety Functions where geo-scientific support is needed; - Commonly used chains of argument for supporting these safety functions; - Whether the applicability of the arguments are host rock or site specific and how they apply for different time frames; - Field evidence or other issues that would go counter to the safety arguments; - Key messages most promising in terms of scientific credibility to contribute to the safety case. Overall it was concluded by the Working Group that: - The most important argument is to present a clear understanding of past geological evolution at the particular site, consistent with the global understanding of geological evolution. Efforts should be made to achieve a broad consensus on this from many independent experts. - The supporting arguments are seldom based on a single piece of evidence. It is the chain of arguments rather than individual arguments that is important. - We are primarily interested in 'reasonable' predictability of the geological system. We recognize that most geological systems evolve with time

Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam

International Nuclear Information System (INIS)

Sugiyama, Yuki; Fukui, Minoru; Kikuchi, Macoto; Hasebe, Katsuya; Nakayama, Akihiro; Nishinari, Katsuhiro; Tadaki, Shin-ichi; Yukawa, Satoshi

2008-01-01

A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like 'dynamical' phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway

Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam

Energy Technology Data Exchange (ETDEWEB)

Sugiyama, Yuki [Department of Complex Systems Science, Nagoya University, Nagoya 464-8601 (Japan); Fukui, Minoru [Nakanihon Automotive College, Sakahogi 505-0077 (Japan); Kikuchi, Macoto [Cybermedia Center, Osaka University, Toyonaka 560-0043 (Japan); Hasebe, Katsuya [Aichi University, Miyoshi 470-0296 (Japan); Nakayama, Akihiro [Faculty of Science and Technology, Meijo University, Nagoya 468-8502 (Japan); Nishinari, Katsuhiro [Department of Aeronautics and Astronautics, University of Tokyo, Bunkyo 113-8656 (Japan); Tadaki, Shin-ichi [Computer and Network Center, Saga University, Saga 840-8502 (Japan); Yukawa, Satoshi [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan)], E-mail: sugiyama@phys.cs.is.nagoya-u.ac.jp

2008-03-15

A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like 'dynamical' phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway.

Mechanisms of Acupuncture Therapy for Cerebral Ischemia: an Evidence-Based Review of Clinical and Animal Studies on Cerebral Ischemia.

Science.gov (United States)

Zhu, Wen; Ye, Yang; Liu, Yi; Wang, Xue-Rui; Shi, Guang-Xia; Zhang, Shuai; Liu, Cun-Zhi

2017-12-01

Ischemic stroke is a major cause of mortality and disability worldwide. As a part of Traditional Chinese Medicine (TCM), acupuncture has been shown to be effective in promoting recovery after stroke. In this article, we review the clinical and experimental studies that demonstrated the mechanisms of acupuncture treatment for cerebral ischemia. Clinical studies indicated that acupuncture activated relevant brain regions, modulated cerebral blood flow and related molecules in stroke patients. Evidence from laboratory indicated that acupuncture regulates cerebral blood flow and metabolism after the interrupt of blood supply. Acupuncture regulates multiple molecules and signaling pathways that lead to excitoxicity, oxidative stress, inflammation, neurons death and survival. Acupuncture also promotes neurogenesis, angiogenesis as well as neuroplasticity after ischemic damage. The evidence provided from clinical and laboratory suggests that acupuncture induces multi-level regulation via complex mechanisms and a single factor may not be enough to explain the beneficial effects against cerebral ischemia.

Reply to: Mounting evidence indicates that escalating doses of allopurinol are unnecessary for cardiovascular protection.

Science.gov (United States)

Coburn, Brian W; Michaud, Kaleb; Bergman, Debra A; Mikuls, Ted R

2018-05-08

We thank Dr. Bredemeier for his comments regarding our manuscript on allopurinol dose escalation and mortality. He raises important evidence to consider in support of an interesting hypothesis that dose escalation may be unnecessary for allopurinol's cardiovascular (CV) protection and may actually be related to adverse CV outcomes. While we agree that evidence exists suggesting that low doses of allopurinol may be sufficient for CV protection, we believe that the studies cited highlight a number of areas where knowledge gaps remain which preclude any definitive conclusions about the effect of dose escalation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Characterization of Evidence for Human System Risk Assessment

Science.gov (United States)

Steinberg, S. L.; Van Baalen, M.; Rossi, M.; Riccio, G.; Romero, E.; Francisco, D.

2016-01-01

Understanding the kinds of evidence available and using the best evidence to answer a question is critical to evidenced-based decision-making, and it requires synthesis of evidence from a variety of sources. Categorization of human system risks in spaceflight, in particular, focuses on how well the integration and interpretation of all available evidence informs the risk statement that describes the relationship between spaceflight hazards and an outcome of interest. A mature understanding and categorization of these risks requires: 1) sufficient characterization of risk, 2) sufficient knowledge to determine an acceptable level of risk (i.e., a standard), 3) development of mitigations to meet the acceptable level of risk, and 4) identification of factors affecting generalizability of the evidence to different design reference missions. In the medical research community, evidence is often ranked by increasing confidence in findings gleaned from observational and experimental research (e.g., "levels of evidence"). However, an approach based solely on aspects of experimental design is problematic in assessing human system risks for spaceflight. For spaceflight, the unique challenges and opportunities include: (1) The independent variables in most evidence are the hazards of spaceflight, such as space radiation or low gravity, which cannot be entirely duplicated in terrestrial (Earth-based) analogs, (2) Evidence is drawn from multiple sources including medical and mission operations, Lifetime Surveillance of Astronaut Health (LSAH), spaceflight research (LSDA), and relevant environmental & terrestrial databases, (3) Risk metrics based primarily on LSAH data are typically derived from available prevalence or incidence data, which may limit rigorous interpretation, (4) The timeframe for obtaining adequate spaceflight sample size (n) is very long, given the small population, (5) Randomized controlled trials are unattainable in spaceflight, (6) Collection of personal and

Time discounting and pain anticipation. Experimental evidence

Directory of Open Access Journals (Sweden)

Brañas Garza, Pablo

2012-03-01

Full Text Available This paper deals with pain anticipation experienced before medical procedures. our experimental results show that individuals with lower time discount factors are more prone to suffer pain in advance. We provide a framework to rationalize the connection between pain anticipation and impatience. in this set up, more impatient subjects, who only value very near events, mainly take into account the present negative effects of medical procedures (the costs, whereas more patient individuals have a net positive valuation of medical events, given that they are able to value both the cost incurred now and all the benefits to be accrued in the future.

Este artículo trata de la anticipación del dolor experimentada antes de los procedimientos médicos. nuestros resultados experimentales muestran que los individuos con factor de descuento temporal más bajo son más proclives a sufrir dolor por adelantado. el artículo proporciona un marco en el que racionalizar la relación existente entre impaciencia y anticipación del dolor. en este marco, los sujetos más impacientes, que evalúan sólo los eventos muy próximos en el tiempo, focalizan su atención principalmente en los efectos negativos de los procedimientos médicos (sólo los costes, mientras que los individuos más pacientes tienen una valoración neta positiva de los actos médicos puesto que valoran tanto el coste en el que se incurre en el presente como los beneficios que se obtendrán en el futuro.

Quality Appraisal of Single-Subject Experimental Designs: An Overview and Comparison of Different Appraisal Tools

Science.gov (United States)

Wendt, Oliver; Miller, Bridget

2012-01-01

Critical appraisal of the research literature is an essential step in informing and implementing evidence-based practice. Quality appraisal tools that assess the methodological quality of experimental studies provide a means to identify the most rigorous research suitable for evidence-based decision-making. In single-subject experimental research,…

Dose-specific effects of transcutaneous electrical nerve stimulation (TENS) on experimental pain: a systematic review.

Science.gov (United States)

Claydon, Leica S; Chesterton, Linda S; Barlas, Panos; Sim, Julius

2011-09-01

To determine the hypoalgesic effects of transcutaneous electrical nerve stimulation (TENS) parameter combinations on experimental models in healthy humans. Searches were performed using the electronic databases Ovid MEDLINE, CINAHL, AMED, and Web of Science (from inception to December 2009). Manual searches of journals and reference lists of retrieved trials were also performed. Randomized controlled trials (RCTs) were included in the review if they compared the hypoalgesic effect of TENS relative with placebo and control, using an experimental pain model in healthy human participants. Two reviewers independently selected the trials, assessed their methodologic quality and extracted data. Forty-three RCTs were eligible for inclusion. A best evidence synthesis revealed: Overall "conflicting" (inconsistent findings in multiple RCTs) evidence of TENS efficacy on experimental pain irrespective of TENS parameters used. Overall intense TENS has "moderate" evidence of efficacy (1 high-quality and 2 low-quality trials). Conventional TENS has overall conflicting evidence of efficacy, this is derived from "strong" evidence of efficacy (generally consistent findings in multiple high-quality RCTs) on pressure pain but strong evidence of inefficacy on other pain models. "Limited" evidence (positive findings from 1 RCT) of hypoalgesia exists for some novel parameters. Low-intensity, low-frequency, local TENS has strong evidence of inefficacy. Inappropriate TENS (using "barely perceptible" intensities) has moderate evidence of inefficacy. The level of hypoalgesic efficacy of TENS is clearly dependent on TENS parameter combination selection (defined in terms of intensity, frequency, and stimulation site) and experimental pain model. Future clinical RCTs may consider these TENS dose responses.

Modulation of Antioxidant Enzymatic Activities by Certain Antiepileptic Drugs (Valproic Acid, Oxcarbazepine, and Topiramate: Evidence in Humans and Experimental Models

Directory of Open Access Journals (Sweden)

Noemí Cárdenas-Rodríguez

2013-01-01

Full Text Available It is estimated that at least 100 million people worldwide will suffer from epilepsy at some point in their lives. This neurological disorder induces brain death due to the excessive liberation of glutamate, which activates the postsynaptic N-methyl-D-aspartic acid (NMDA receptors, which in turn cause the reuptake of intracellular calcium (excitotoxicity. This excitotoxicity elicits a series of events leading to nitric oxide synthase (NOS activation and the generation of reactive oxygen species (ROS. Several studies in experimental models and in humans have demonstrated that certain antiepileptic drugs (AEDs exhibit antioxidant effects by modulating the activity of various enzymes associated with this type of stress. Considering the above-mentioned data, we aimed to compile evidence elucidating how AEDs such as valproic acid (VPA, oxcarbazepine (OXC, and topiramate (TPM modulate oxidative stress.

The Measurement of Central Bank Autonomy; Survey of Models, Indicators, and Empirical Evidence

OpenAIRE

Bernard J Laurens; Marco Arnone; Jean-François Segalotto

2006-01-01

This paper presents a survey of the literature on the measurement of central bank autonomy. We distinguish inputs that constitute the building blocks in the literature, and the literature that builds on them. Issues including sensitivity analysis, robustness, and endogeneity are discussed. The review shows that empirical evidence regarding the beneficial effects of central bank autonomy is substantial, although some technical issues still remain for further research. In particular, central ba...

In vivo evidence for CD4+ and CD8+ suppressor T cells in vaccination-induced suppression of murine experimental autoimmune thyroiditis

International Nuclear Information System (INIS)

Flynn, J.C.; Kong, Y.C.

1991-01-01

In several experimental autoimmune diseases, including experimental autoimmune thyroiditis (EAT), vaccination with attenuated autoantigen-specific T cells has provided protection against subsequent induction of disease. However, the mechanism(s) of vaccination-induced suppression remains to be clarified. Since the authors have previously shown that suppression generated by pretreatment with mouse thyroglobulin (MTg) or thyroid-stimulating hormone in EAT is mediated by CD4+, not CD8+, suppressor T cells, they examined the role of T cell subsets in vaccination-induced suppression of EAT. Mice were vaccinated with irradiated, MTg-primed, and MTg-activated spleen cells and then challenged. Pretreatment with these cells suppressed EAT induced by immunization with MTg and adjuvant, but not by adoptive transfer of thyroiditogenic cells, suggesting a mechanism of afferent suppression. The activation of suppressor mechanisms did not require CD8+ cells, since mice depleted of CD8+ cells before vaccination showed reduced EAT comparable to control vaccinated mice. Furthermore, depletion of either the CD4+ or the CD8+ subset after vaccination did not significantly abrogate suppression. However, suppression was eliminated by the depletion of both CD4+ and CD8+ cells in vaccinated mice. These results provide evidence for the cooperative effects of CD4+ and CD8+ T cells in vaccination-induced suppression of EAT

Relative Release-to-Birth Indicators for Investigating TRISO Fuel Fission Gas Release Models

International Nuclear Information System (INIS)

Harp, Jason M.; Hawari, Ayman I.

2008-01-01

TRISO microsphere fuel is the fundamental fuel unit for Very High Temperature Reactors (VHTR). A single TRISO particle consists of an inner kernel of uranium dioxide or uranium oxycarbide surrounded by layers of pyrolytic carbon and silicon carbide. If the silicon carbide layer fails, fission products, especially the noble fission gases Kr and Xe, will begin to escape the failed particle. The release of fission gas is usually quantified by measuring the ratio of the released activity (R) to the original birth activity (B), which is designated as the R/B ratio. In this work, relative Release-to-Birth indicators (I) are proposed as a technique for interpreting the results of TRISO irradiation experiments. By implementing a relative metric, it is possible to reduce the sensitivity of the indicators to instrumental uncertainties and variations in experimental conditions. As an example, relative R/B indicators are applied to the interpretation of representative data from the Advanced Gas Reactor-1 TRISO fuel experiment that is currently taking place at the Advanced Test Reactor of Idaho National Laboratory. It is shown that the comparison of measured to predicted relative R/B indicators (I) gives insight into the physics of release and helps validate release models. Different trends displayed by the indicators are related to the mechanisms of fission gas release such as diffusion and recoil. The current analysis shows evidence for separate diffusion coefficients for Kr and Xe and supports the need to account for recoil release. (authors)

Fuzzy method of recognition of high molecular substances in evidence-based biology

Science.gov (United States)

Olevskyi, V. I.; Smetanin, V. T.; Olevska, Yu. B.

2017-10-01

Nowadays modern requirements to achieving reliable results along with high quality of researches put mathematical analysis methods of results at the forefront. Because of this, evidence-based methods of processing experimental data have become increasingly popular in the biological sciences and medicine. Their basis is meta-analysis, a method of quantitative generalization of a large number of randomized trails contributing to a same special problem, which are often contradictory and performed by different authors. It allows identifying the most important trends and quantitative indicators of the data, verification of advanced hypotheses and discovering new effects in the population genotype. The existing methods of recognizing high molecular substances by gel electrophoresis of proteins under denaturing conditions are based on approximate methods for comparing the contrast of electrophoregrams with a standard solution of known substances. We propose a fuzzy method for modeling experimental data to increase the accuracy and validity of the findings of the detection of new proteins.

Skeletal Indicators of Shark Feeding on Human Remains: Evidence from Florida Forensic Anthropology Cases.

Science.gov (United States)

Stock, Michala K; Winburn, Allysha P; Burgess, George H

2017-11-01

This research examines a series of six Florida forensic anthropology cases that exhibit taphonomic evidence of marine deposition and shark-feeding activities. In each case, we analyzed patterns of trauma/damage on the skeletal remains (e.g., sharp-force bone gouges and punctures) and possible mechanisms by which they were inflicted during shark predation/scavenging. In some cases, shark teeth were embedded in the remains; in the absence of this evidence, we measured interdental distance from defects in the bone to estimate shark body length, as well as to draw inferences about the potential species responsible. We discuss similarities and differences among the cases and make comparisons to literature documenting diagnostic shark-inflicted damage to human remains from nearby regions. We find that the majority of cases potentially involve bull or tiger sharks scavenging the remains of previously deceased, adult male individuals. This scavenging results in a distinctive taphonomic signature including incised gouges in cortical bone. © 2017 American Academy of Forensic Sciences.

THEORETICAL AND EXPERIMENTAL EVALUATION OF STRENGTH INDICES OF BOGIE FRAME TRANSOMS FOR TRAILING CARS OF ELECTRIC TRAINS ER9M, ER9E

Directory of Open Access Journals (Sweden)

O. M. Bondarev

2013-10-01

Full Text Available Purpose. The article objectives are to identify the factors, which can contribute to the formation of cracks and to develop the measures on improving the strength indices of bogie frame transoms of trailing cars. Methodology. In order to achieve these objectives, in performing the work it was conducted the inspection of the technical condition of supporting structures for bogie frames of trailing cars; measured the Brіnell hardness numbers and estimated the endurance limits of transom material; tested on determination of the levels of efforts and stresses being created in the specified transoms under operation; developed the computational models for the theoretical determination of stress levels in the transom by simulating both normal and abnormal conditions of operating loading. Findings. Based on the analysis of results obtained: the situations with the highest stress levels were found; the measures on improving the strength indices of bogie frame transoms of trailing cars were developed. Originality. Based on the experimental and theoretical studies, the scientific monitoring of works to develop the measures on improving the strength indices of bogie frame transoms of trailing cars was carried out. Practical value. The developed measures on improving the strength indices were passed to professionals of Ukrzaliznytsia to introduce the proposed activities during the repairs of electric trains of specified series.

GEOMORPHOLOGY. Experimental evidence for hillslope control of landscape scale.

Science.gov (United States)

Sweeney, K E; Roering, J J; Ellis, C

2015-07-03

Landscape evolution theory suggests that climate sets the scale of landscape dissection by modulating the competition between diffusive processes that sculpt convex hillslopes and advective processes that carve concave valleys. However, the link between the relative dominance of hillslope and valley transport processes and landscape scale is difficult to demonstrate in natural landscapes due to the episodic nature of erosion. Here, we report results from laboratory experiments combining diffusive and advective processes in an eroding landscape. We demonstrate that rainsplash-driven disturbances in our experiments are a robust proxy for hillslope transport, such that increasing hillslope transport efficiency decreases drainage density. Our experimental results demonstrate how the coupling of climate-driven hillslope- and valley-forming processes, such as bioturbation and runoff, dictates the scale of eroding landscapes. Copyright © 2015, American Association for the Advancement of Science.

A multidisciplinary weight of evidence approach for environmental risk assessment at the Costa Concordia wreck: Integrative indices from Mussel Watch.

Science.gov (United States)

Regoli, Francesco; Pellegrini, David; Cicero, Anna Maria; Nigro, Marco; Benedetti, Maura; Gorbi, Stefania; Fattorini, Daniele; D'Errico, Giuseppe; Di Carlo, Marta; Nardi, Alessandro; Gaion, Andrea; Scuderi, Alice; Giuliani, Silvia; Romanelli, Giulia; Berto, Daniela; Trabucco, Benedetta; Guidi, Patrizia; Bernardeschi, Margherita; Scarcelli, Vittoria; Frenzilli, Giada

2014-05-01

A complex framework of chemical, biological and oceanographic activities was immediately activated after the Costa Concordia shipwreck, to assess possible contamination events and the environmental impact during both emergency and wreck removal operations. In the present paper, we describe the results obtained with caged mussels, Mytilus galloprovincialis, chosen as bioindicator organisms to detect variations of bioavailability and the early onset of molecular and cellular effects (biomarkers). Seven translocation experiments were carried out during the first year from the incident, with organisms deployed at 2 depths in 3 different sites. After 4-6 weeks, tissue concentrations were measured for the main classes of potentially released chemicals (trace metals, polycyclic aromatic hydrocarbons, volatile and aliphatic hydrocarbons, polychlorinated biphenyls, halogenated pesticides, organotin compounds, brominated flame retardants, anionic surfactants); a wide battery of biomarkers covered responses indicative of exposure, detoxification, oxidative stress, cell damage and genotoxic effects. Results excluded serious contamination events or a consistent increase of environmental pollution although some episodic spills with reversible effects were detected. Data were elaborated within a quantitative weight of evidence (WOE) model which provided synthetic hazard indices for each typology of data, before their overall integration in an environmental risk index, which generally ranged from slight to moderate. The proposed WOE model was confirmed a useful tool to summarize large datasets of complex data in integrative indices, and to simplify the interpretation for stakeholders and decision makers, thus supporting a more comprehensive process of "site-oriented" management decisions. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Medical indications for acupuncture: Systematic review].

Science.gov (United States)

Muñoz-Ortego, Juan; Solans-Domènech, Maite; Carrion, Carme

2016-09-16

Acupuncture is a medical procedure with a very wide range of indications according to the WHO. However the indications require robust scientific evidence to support them. We have conducted a systematic review (2010-2015) in order to define in which pathologies acupuncture can be an effective strategy, STRICTA criteria that aim to set up acupuncture clinical trials standard criteria were defined in 2010. Only systematic reviews and meta-analyses of good or very good methodological quality according to SIGN criteria were selected. Its main objective was to evaluate the effectiveness of acupuncture in the management of any disease. Most of the final 31 selected reviews focus on chronic pain-related diseases, mainly in the disciplines of Neurology, Orthopaedics and Rheumatology. Current evidence supports the use of acupuncture in the treatment of headaches, migraines, back pain, cervical pain and osteoarthritis. The remaining pathologies still require further good quality studies. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Pain perception in people with Down syndrome: a synthesis of clinical and experimental research

Science.gov (United States)

McGuire, Brian E.; Defrin, Ruth

2015-01-01

People with an intellectual disability experience both acute and chronic pain with at least the same frequency as the general population. However, considerably less is known about the pain perception of people with Down syndrome. In this review paper, we evaluated the available clinical and experimental evidence. Some experimental studies of acute pain have indicated that pain threshold was higher than normal but only when using a reaction time method to measure pain sensitivity. However, when reaction time is not part of the calculation of the pain threshold, pain sensitivity in people with Down syndrome is in fact lower than normal (more sensitive to pain). Clinical studies of chronic pain have shown that people with an intellectual disability experience chronic pain and within that population, people with Down syndrome also experience chronic pain, but the precise prevalence of chronic pain in Down syndrome has yet to be established. Taken together, the literature suggests that people with Down syndrome experience pain, both acute and chronic, with at least the same frequency as the rest of the population. Furthermore, the evidence suggests that although acute pain expression appears to be delayed, once pain is registered, there appears to be a magnified pain response. We conclude by proposing an agenda for future research in this area. PMID:26283936

Experimental determination of spectral indices by scanning of fuel rod in the IPEN/MB-01 reactor

International Nuclear Information System (INIS)

Fanaro, Leda Cristina Cabelo Bernardes

2009-01-01

In this work, the spectral indexes 28ρ * and 25δ * , and gamma efficiency factor in the IPEN/MB-01 reactor were determined experimentally employing a rod scanning technique. In the case of 28ρ * , this method has the advantage of eliminating most of the correction factors derived from the calculations. Only the fission yield factor and the relative fission rate in the 235 U remain in the determination of the 25δ * . The experiments were performed with different thicknesses of cadmium sleeves: 0.55 mm, 1.10 mm and 2.20 mm. The final experimental uncertainty achieved in the experiment, less that 1 %, and the excellent geometrical and material data characterization of the IPEN/MB-01 reactor allow to use the results as benchmark for validate calculation methods and related nuclear data libraries. The comparison between calculated values and experimental values was performed by employing the MCNP-5 code and the nuclear data libraries: ENDF/B-VI.8, ENDF/B-VII.0, JENDL-3.3 and JEFF-3.1. The results demonstrate that the difference among libraries is very small. Also, the comparison between calculated values and experimental values shows that there has been considerable progress in the recent nuclear data libraries. The best result is obtained with ENDF/B-VII.0 nuclear data library, and the highest discrepancy was obtained with JEFF-3.1 and JENDL-3.3 nuclear data libraries. (author)

Superheavy Elements Challenge Experimental and Theoretical Chemistry

CERN Document Server

Zvára, I

2003-01-01

When reflecting on the story of superheavy elements, the an experimenter, acknowledges the role, which the predictions of nuclear and chemical theories have played in ongoing studies. Today, the problems of major interest for experimental chemistry are the studies of elements 112 and 114 including their chemical identification. Advanced quantum chemistry calculations of atoms and molecules would be of much help. First experiments with element 112 evidence that the metal is much more volatile and inert than mercury.

Experimental study on heat transfer augmentation of graphene based ferrofluids in presence of magnetic field

DEFF Research Database (Denmark)

Sadeghinezhad, Emad; Mehrali, Mohammad; Akhiani, Amir Reza

2017-01-01

The effect of a permanent magnetic field on the heat transfer characteristics of hybrid graphene-magnetite nanofluids (hybrid nanofluid) under forced laminar flow was experimentally investigated. For this purpose, a reduced graphene oxide-Fe3O4 was synthesized by using two-dimensional (2D) graphene...... and it shows that the thermal conductivity increased up to 11%. The hybrid nanofluid behaves as a Newtonian fluid with liquid like behavior with superparamagnetic properties as was evident from its magnetic saturation value at 45.9 emu/g. Moreover, the experimental heat-transfer results indicated that the heat...... transfer enhancement of the hybrid nanofluid compared to the control fluid (distilled water) was negligible when no magnetic field was applied. Additionally, the convective heat transfer was significantly improved under the influence of a magnetic field with a maximum enhancement of 82% in terms...

Evidence for subwavelength imaging with positive refraction

Energy Technology Data Exchange (ETDEWEB)

Ma, Yun Gui [Temasek Laboratories, National University of Singapore, Singapore 119260 (Singapore); Sahebdivan, Sahar; Tyc, Tomas; Leonhardt, Ulf [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Ong, C K, E-mail: ulf@st-andrews.ac.uk [Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

2011-03-15

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction.

Evidence for subwavelength imaging with positive refraction

International Nuclear Information System (INIS)

Ma, Yun Gui; Sahebdivan, Sahar; Tyc, Tomas; Leonhardt, Ulf; Ong, C K

2011-01-01

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction.

Experimental evidence of energetic neutrals production in an ion diode

Energy Technology Data Exchange (ETDEWEB)

Pushkarev, A.I., E-mail: aipush@mail.ru; Isakova, Y.I.; Khaylov, I.P.

2015-01-15

The paper presents several experimental proofs of the formation of energetic charge-exchange neutrals in a self-magnetically insulated ion diode with a graphite cathode. The energetic neutrals are thought to be produced as a result of charge exchange process between accelerated ions and stationary neutral molecules. The experiments have been carried out using both a diode with externally applied magnetic insulation (single-pulse mode: 100 ns, 250–300 kV) and a diode with self-magnetic insulation (double-pulse mode: 300–500 ns, 100–150 kV (negative pulse); 120 ns, 250–300 kV (positive pulse)). The motivation for looking at the neutral component of the ion beam came when we compared two independent methods to measure the energy density of the beam. A quantitative comparison of infrared measurements with signals from Faraday cups and diode voltage was made to assess the presence of neutral atoms in the ion beam. As another proof of charge-exchange effects in ion diode we present the results of statistical analysis of diode performance. It was found that the shot-to shot variation of the energy density in a set of 50–100 shots does not exceed 11%, whilst the same variation for ion current density was 20–30%; suggesting the presence of neutrals in the beam. Moreover, the pressure in the zone of ion beam energy dissipation exceeds the results stated in cited references. The difference between our experimental data and results stated by other authors we attribute to the presence of a low-energy charge-exchange neutral component in the ion beam.

Experimental canine distemper infection as a means of demonstrating latent effects of subacute lead intoxication

Energy Technology Data Exchange (ETDEWEB)

White, D.J.; McLeod, S.

1976-01-01

Observations on the response of the body to experimental infection with distemper virus in dogs previously dosed subacutely with lead have demonstrated a latent effect of lead on several body systems. Effects which indicated a relationship to earlier treatment with lead included evidence for stimulation of haemoglobin synthesis, changes to red blood cells resulting in increased destruction, increased vulnerability of the parenchymatous cells of the liver to damage, reduction in the weight of the skeleton and thyroid, an increase in weight of the thymus and brain and histopathological changes in the thymus. 21 references, 2 figures, 1 table.

Expert opinion vs. empirical evidence

Science.gov (United States)

Herman, Rod A; Raybould, Alan

2014-01-01

Expert opinion is often sought by government regulatory agencies when there is insufficient empirical evidence to judge the safety implications of a course of action. However, it can be reckless to continue following expert opinion when a preponderance of evidence is amassed that conflicts with this opinion. Factual evidence should always trump opinion in prioritizing the information that is used to guide regulatory policy. Evidence-based medicine has seen a dramatic upturn in recent years spurred by examples where evidence indicated that certain treatments recommended by expert opinions increased death rates. We suggest that scientific evidence should also take priority over expert opinion in the regulation of genetically modified crops (GM). Examples of regulatory data requirements that are not justified based on the mass of evidence are described, and it is suggested that expertise in risk assessment should guide evidence-based regulation of GM crops. PMID:24637724

Do Decentralized Innovation Systems Promote Agricultural Technology Adoption? Experimental Evidence from Africa

NARCIS (Netherlands)

Pamuk, Haki; Bulte, Erwin|info:eu-repo/dai/nl/141315245; Adekunle, Adewale A.

2014-01-01

We use experimental data collected in 8 African countries to investigate whether a decentralized approach can promote the adoption of agricultural innovations. This participatory model is based on the creation of so-called ‘innovation platforms’ where local stakeholders meet and seek to identify

Theoretical and experimental indicators of falls during pregnancy as assessed by postural perturbations.

Science.gov (United States)

Ersal, Tulga; McCrory, Jean L; Sienko, Kathleen H

2014-01-01

Throughout pregnancy, women experience physical, physiological, and hormonal alterations that are often accompanied by decreased postural control. According to one study, nearly 27% of pregnant women fell while pregnant. This study had two objectives: (1) to characterize the postural responses of pregnant fallers, nonfallers, and controls to surface perturbations, and (2) to develop a mathematical model to gain insights into the postural control strategies of each group. This retrospective analysis used experimental data obtained from 15 women with a fall history during pregnancy, 14 women without a fall history during pregnancy, and 40 nonpregnant controls. Small, medium, and large translational support surface perturbations in the anterior and posterior directions were performed during the pregnant participants' second and third trimesters. A two-segmented mathematical model of bipedal stance was developed and parameterized, and optimization tools were used to identify ankle and hip stiffness, viscosity, and the feedback time delay by searching for the best fits to experimental COP data. The peak differences between the center of pressure and center of gravity (COP-COG) values were significantly smaller for the pregnant fallers compared with the pregnant nonfallers and controls (pcontrols, which suggests that ankle stiffness itself may be the dominant reason for the different dynamic response characteristics (e.g., peak COP-COG) observed. We conclude that increasing ankle stiffness could be an important strategy to prevent falling by pregnant women. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental evidence of a chaotic region in a neural pacemaker

Energy Technology Data Exchange (ETDEWEB)

Gu, Hua-Guang, E-mail: guhuaguang@tongji.edu.cn [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR (China); Jia, Bing [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Chen, Guan-Rong [Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR (China)

2013-03-15

In this Letter, we report the finding of period-adding scenarios with chaos in firing patterns, observed in biological experiments on a neural pacemaker, with fixed extra-cellular potassium concentration at different levels and taken extra-cellular calcium concentration as the bifurcation parameter. The experimental bifurcations in the two-dimensional parameter space demonstrate the existence of a chaotic region interwoven with the periodic region thereby forming a period-adding sequence with chaos. The behavior of the pacemaker in this region is qualitatively similar to that of the Hindmarsh–Rose neuron model in a well-known comb-shaped chaotic region in two-dimensional parameter spaces.

Experimental evidence for a vector-like behaviour of Pomeron exchange

CERN Document Server

Barberis, D.; Close, F.E.; Danielsen, K.M.; Donskov, S.V.; Earl, B.C.; Evans, D.; French, B.R.; Hino, T.; Inaba, S.; Jacholkowski, A.; Jacobsen, T.; Khaustov, G.V.; Kinson, J.B.; Kirk, A.; Kondashov, A.A.; Lednev, A.A.; Lenti, V.; Minashvili, I.; Peigneux, J.P.; Romanovsky, V.; Russakovich, N.; Semenov, A.; Shagin, P.M.; Shimizu, H.; Singovsky, A.V.; Sobol, A.; Stassinaki, M.; Stroot, J.P.; Takamatsu, K.; Tsuru, T.; Villalobos Baillie, O.; Votruba, M.F.; Yasu, Y.

1999-01-01

Evidence is presented that the Pomeron act as a non-conserved vector current. A study has been made of the azimuthal angle phi, which is defined as the angle between the pT vectors of the two outgoing protons, in the reaction pp -> pp(X0) for those resonances (X0) which are compatible with being produced by double Pomeron exchange. These distributions have been compared with a model which describes the Pomeron as a non-conserved vector current and a qualitative agreement is found. In addition, when one of the particles exchanged is known to have spin 0, namely pi-Pomeron exchange, the phi distribution is flat.

Nanosecond electrical explosion of thin aluminum wire in vacuum: experimental and computational investigations

International Nuclear Information System (INIS)

Cochrane, Kyle Robert; Struve, Kenneth William; Rosenthal, Stephen Edgar; McDaniel, Dillon Heirman; Sarkisov, Gennady Sergeevich; Deeney, Christopher

2004-01-01

The experimental and computational investigations of nanosecond electrical explosion of thin Al wire in vacuum are presented. We have demonstrated that increasing the current rate leads to increased energy deposited before voltage collapse. Laser shadowgrams of the overheated Al core exhibit axial stratification with a ∼100 (micro)m period. The experimental evidence for synchronization of the wire expansion and light emission with voltage collapse is presented. Two-wavelength interferometry shows an expanding Al core in a low-ionized gas condition with increasing ionization toward the periphery. Hydrocarbons are indicated in optical spectra and their influence on breakdown physics is discussed. The radial velocity of low-density plasma reaches a value of ∼100 km/s. The possibility of an overcritical phase transition due to high pressure is discussed. 1D MHD simulation shows good agreement with experimental data. MHD simulation demonstrates separation of the exploding wire into a high-density cold core and a low-density hot corona as well as fast rejection of the current from the wire core to the corona during voltage collapse. Important features of the dynamics for wire core and corona follow from the MHD simulation and are discussed.

Evidence for K+ -> π+ νbar ν

International Nuclear Information System (INIS)

Kettell, S.

1998-01-01

The first observation of the decay K + -> π + νbar ν has been reported. The E787 experiment presented evidence for the K + r a rrow π + νbar ν decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, B(K + -> π + νbar ν) = 4.2 -3.5 +9.7 x 10 -10 , is consistent with the Standard Model expectation although the central experimental value is four times larger. The final E787 data sample, from the 1995--98 runs, should reach a sensitivity of about five times that of the 1995 run alone. A new experiment, E949, has been given scientific approval and should start data collection in 2001. It is expected to achieve a sensitivity of more than an order of magnitude below the prediction of the Standard Model

Experimental evidence for vortex-glass superconductivity in Y-Ba-Cu-O

International Nuclear Information System (INIS)

Koch, R.H.; Foglietti, V.; Gallagher, W.J.; Koren, G.; Gupta, A.; Fisher, M.P.A.

1989-01-01

We demonstrate experimentally the existence of a continuous phase transition between a normal and a true superconducting phase (with zero linear resistivity) in epitaxial films of Y-Ba-Cu-O in strong magnetic fields fields, H much-gt H c1 . The nonlinear I-V curves show scaling behavior near the transition and the relevant critical exponents are extracted. These exponents are consistent with values expected for freezing into a superconducting vortex-glass phase

Experimental Evidence that Abrasion of Carbonate Sand is a Significant Source of Carbonate Mud

Science.gov (United States)

Trower, L.; Kivrak, L.; Lamb, M. P.; Fischer, W. W.

2017-12-01

Carbonate mud is a major sedimentary component of modern and ancient tropical carbonate environments, yet its enigmatic origin remains debated. Early views on the origin of carbonate mud considered the abrasion of carbonate sand during sediment transport as a possible mechanism. In recent decades, however, prevailing thought has generally settled on a binary explanation: 1) precipitation of aragonite needles within the water column, and 2) post-mortem dispersal of biological aragonite, in particular from algae, and perhaps aided by fish. To test these different hypotheses, we designed a model and a set of laboratory experiments to quantify the rates of mud production associated with sediment transport. We adapted a recent model of ooid abrasion rate to predict the rate of mud production by abrasion of carbonate sand as a function of grain size and sediment transport mode. This model predicts large mud production rates, ranging from 103 to 104 g CaCO3/m2/yr for typical grain sizes and transport conditions. These rate estimates are at least one order of magnitude more rapid than the 102 g CaCO3/m2/yr estimates for other mechanisms like algal biomineralization, indicating that abrasion could produce much larger mud fluxes per area as other mechanisms. We tested these estimates using wet abrasion mill experiments; these experiments generated mud through mechanical abrasion of both ooid and skeletal carbonate sand for grain sizes ranging from 250 µm to >1000 µm over a range of sediment transport modes. Experiments were run in artificial seawater, including a series of controls demonstrating that no mud was produced via homogenous nucleation and precipitation in the absence of sand. Our experimental rates match the model predictions well, although we observed small systematic differences in rates between abrasion ooid sand and skeletal carbonate sand that likely stems from innate differences in grain angularity. Electron microscopy of the experimental products revealed

Microencapsulation of Corrosion Indicators for Smart Coatings

Science.gov (United States)

Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott T.; Calle, Luz M.; Hanna,Joshua S.; Rawlins, James W.

2011-01-01

A multifunctional smart coating for the autonomous detection, indication, and control of corrosion is been developed based on microencapsulation technology. This paper summarizes the development, optimization, and testing of microcapsules specifically designed for early detection and indication of corrosion when incorporated into a smart coating. Results from experiments designed to test the ability of the microcapsules to detect and indicate corrosion, when blended into several paint systems, show that these experimental coatings generate a color change, indicative of spot specific corrosion events, that can be observed with the naked eye within hours rather than the hundreds of hours or months typical of the standard accelerated corrosion test protocols.. Key words: smart coating, corrosion detection, microencapsulation, microcapsule, pH-sensitive microcapsule, corrosion indicator, corrosion sensing paint

Experimental and computational evidence of halogen bonds involving astatine

Science.gov (United States)

Guo, Ning; Maurice, Rémi; Teze, David; Graton, Jérôme; Champion, Julie; Montavon, Gilles; Galland, Nicolas

2018-03-01

The importance of halogen bonds—highly directional interactions between an electron-deficient σ-hole moiety in a halogenated compound and an acceptor such as a Lewis base—is being increasingly recognized in a wide variety of fields from biomedicinal chemistry to materials science. The heaviest halogens are known to form stronger halogen bonds, implying that if this trend continues down the periodic table, astatine should exhibit the highest halogen-bond donating ability. This may be mitigated, however, by the relativistic effects undergone by heavy elements, as illustrated by the metallic character of astatine. Here, the occurrence of halogen-bonding interactions involving astatine is experimentally evidenced. The complexation constants of astatine monoiodide with a series of organic ligands in cyclohexane solution were derived from distribution coefficient measurements and supported by relativistic quantum mechanical calculations. Taken together, the results show that astatine indeed behaves as a halogen-bond donor—a stronger one than iodine—owing to its much more electrophilic σ-hole.

A Tax Evasion - Bribery Game: Experimental Evidence from Ukraine

Directory of Open Access Journals (Sweden)

Volodymyr Bilotkach

2006-06-01

Full Text Available This paper examines the issue of tax evasion by enterprises through underreporting activity. We develop a view of this phenomenon as an equilibrium of the game between a businessman and an imperfectly monitored supervising official, in which a businessman can hide part of his profit and offer bribe to official. We determine conditions under which such tax evasion and bribery become wide-spread in the society, resulting in shadow economy. The game is put into an experimental setting in Kiev, Ukraine, with the emphasis of spreading of the tax evasion and bribery activity in the laboratory setting. We find that once it becomes known that substantial share of subjects playing the role of supervising officials agree to accept bribes from subjects playing the role of businessmen, the latter offer bribes more aggressively. Yet, this in turn does not affect the behavior of subjects playing the role of supervising officials.

Effectiveness of student learning during experimental work in primary school

OpenAIRE

Logar, Ana; Peklaj, Cirila; Ferk Savec, Vesna

2017-01-01

The aim of the research was to optimize the effectiveness of student learning based on experimental work in chemistry classes in Slovenian primary schools. To obtain evidence about how experimental work is implemented during regular chemistry classes, experimental work was videotaped during 19 units of chemistry lessons at 12 Slovenian primary schools from the pool of randomly selected schools. Altogether 332 eight-grade students were involved in the investigation, with an average...

Pollinator-driven ecological speciation in plants: new evidence and future perspectives.

Science.gov (United States)

Van der Niet, Timotheüs; Peakall, Rod; Johnson, Steven D

2014-01-01

The hypothesis that pollinators have been important drivers of angiosperm diversity dates back to Darwin, and remains an important research topic today. Mounting evidence indicates that pollinators have the potential to drive diversification at several different stages of the evolutionary process. Microevolutionary studies have provided evidence for pollinator-mediated floral adaptation, while macroevolutionary evidence supports a general pattern of pollinator-driven diversification of angiosperms. However, the overarching issue of whether, and how, shifts in pollination system drive plant speciation represents a critical gap in knowledge. Bridging this gap is crucial to fully understand whether pollinator-driven microevolution accounts for the observed macroevolutionary patterns. Testable predictions about pollinator-driven speciation can be derived from the theory of ecological speciation, according to which adaptation (microevolution) and speciation (macroevolution) are directly linked. This theory is a particularly suitable framework for evaluating evidence for the processes underlying shifts in pollination systems and their potential consequences for the evolution of reproductive isolation and speciation. This Viewpoint paper focuses on evidence for the four components of ecological speciation in the context of plant-pollinator interactions, namely (1) the role of pollinators as selective agents, (2) floral trait divergence, including the evolution of 'pollination ecotypes', (3) the geographical context of selection on floral traits, and (4) the role of pollinators in the evolution of reproductive isolation. This Viewpoint also serves as the introduction to a Special Issue on Pollinator-Driven Speciation in Plants. The 13 papers in this Special Issue range from microevolutionary studies of ecotypes to macroevolutionary studies of historical ecological shifts, and span a wide range of geographical areas and plant families. These studies further illustrate

Pollinator-driven ecological speciation in plants: new evidence and future perspectives

Science.gov (United States)

Van der Niet, Timotheüs; Peakall, Rod; Johnson, Steven D.

2014-01-01

Background The hypothesis that pollinators have been important drivers of angiosperm diversity dates back to Darwin, and remains an important research topic today. Mounting evidence indicates that pollinators have the potential to drive diversification at several different stages of the evolutionary process. Microevolutionary studies have provided evidence for pollinator-mediated floral adaptation, while macroevolutionary evidence supports a general pattern of pollinator-driven diversification of angiosperms. However, the overarching issue of whether, and how, shifts in pollination system drive plant speciation represents a critical gap in knowledge. Bridging this gap is crucial to fully understand whether pollinator-driven microevolution accounts for the observed macroevolutionary patterns. Testable predictions about pollinator-driven speciation can be derived from the theory of ecological speciation, according to which adaptation (microevolution) and speciation (macroevolution) are directly linked. This theory is a particularly suitable framework for evaluating evidence for the processes underlying shifts in pollination systems and their potential consequences for the evolution of reproductive isolation and speciation. Scope This Viewpoint paper focuses on evidence for the four components of ecological speciation in the context of plant-pollinator interactions, namely (1) the role of pollinators as selective agents, (2) floral trait divergence, including the evolution of ‘pollination ecotypes‘, (3) the geographical context of selection on floral traits, and (4) the role of pollinators in the evolution of reproductive isolation. This Viewpoint also serves as the introduction to a Special Issue on Pollinator-Driven Speciation in Plants. The 13 papers in this Special Issue range from microevolutionary studies of ecotypes to macroevolutionary studies of historical ecological shifts, and span a wide range of geographical areas and plant families. These studies

Field induced decrystallization of silicon: Evidence of a microwave non-thermal effect

Science.gov (United States)

Nozariasbmarz, Amin; Dsouza, Kelvin; Vashaee, Daryoosh

2018-02-01

It is rather strange and not fully understood that some materials decrystallize when exposed to microwave radiation, and it is still debatable if such a transformation is a thermal or non-thermal effect. We hereby report experimental evidences that weight the latter effect. First, a single crystal silicon wafer exposed to microwaves showed strong decrystallization at high temperature. Second, when some areas of the wafer were masked with metal coating, only the exposed areas underwent decrystallization. Transmission electron microscopy analysis, x-ray diffraction data, and thermal conductivity measurements all indicated strong decrystallization, which occurred in the bulk of the material and was not a surface effect. These observations favor the existence of a non-thermal microwave effect.

Jogos de Empresas e Economia Experimental: um Estudo da Racionalidade Organizacional na Tomada de Decisão

Directory of Open Access Journals (Sweden)

Antonio Carlos Aidar Sauaia

2009-04-01

Full Text Available Through the empirical analysis of behavior in business games, this paper contributes to the discussion of the classical theories on decision making, especially the studies of Simon. Primary data from sequential experiments were collected from business games that operated as laboratory experiments. According to the theorists of Experimental Economics and Behavioral Finance (Barberis & Thaler, 2003; Breinholt, Chesteen, & Cooper, 1992; Shiller, 2000; Simon, 1957, 1976, there was evidence that the choices of some individuals were rational, although in a limited way, producing results in disagreement with the expected utility theory. Their judgment prevented their organizations from maximizing the results because of some cognitive factors (Simon as cited in Bazerman, 2004, p. 6 such as simplification, lack of criteria, time restriction, cost restriction, perception and the ability to retain information in the memory. The subjectively rational decisions (rational a priori, which seemed to align means and ends, were shown to be inefficient (a posteriori reducing the organizational performance indicator (internal rate of return and lowering incentives for the managers (performance evaluation. The evidence shown here, based on objective data and observations, makes it possible to study problems in the field of Experimental Economics through business games

A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust.

Science.gov (United States)

PytlikZillig, Lisa M; Kimbrough, Christopher D; Shockley, Ellie; Neal, Tess M S; Herian, Mitchel N; Hamm, Joseph A; Bornstein, Brian H; Tomkins, Alan J

2017-01-01

This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental

A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust.

Directory of Open Access Journals (Sweden)

Lisa M PytlikZillig

Full Text Available This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence

Experimental Evidence of the Knowledge Gap: Message Arousal, Motivation, and Time Delay

Science.gov (United States)

Grabe, Maria Elizabeth; Yegiyan, Narine; Kamhawi, Rasha

2008-01-01

This study experimentally tested the knowledge gap from an information processing perspective. Specifically, knowledge acquisition was investigated under conditions of medium and low news message arousal, with time delay. Results show the persistence of a knowledge gap, particularly for low arousing messages. In fact, at low levels of message…

Evidence for subwavelength imaging with positive refraction

OpenAIRE

Ma, Yun Gui; Sahebdivan, Sahar; Ong, C. K.; Tyc, Tomas; Leonhardt, Ulf

2011-01-01

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction. Publisher PDF Peer reviewed

Experimental study of the effect of task priority and coordination strategy on crew performance

International Nuclear Information System (INIS)

Braarud, Per Oeivind; Ludvigsen, Jan Tore

2002-08-01

This report documents the background and the results from the Teamwork and Task Management experiment 2001 (TTM-2001) performed in the HAlden Man-Machine LABoratory (HAMMLAB). The experiment emphasises concepts that are suggested as an alternative to the application of general workload measures, namely (1) task management; how operators plan, prioritise and accomplish their tasks individually, and (2) teamwork; coordination of work within the team. The concepts were operationalised for the experimental study by crews operating in accordance with 4 work styles combined from 2 experimental factors: Task Priority and Coordination Strategy. The results indicate that Task Priority has no effect on the operator's ability to handle plant malfunction, but that it increases operator ability to prioritise between the importance of the process data, and increases subjective performance. The results demonstrate that Coordination Strategies significantly improve crew performance. However, contrary to the expectations, there is no clear evidence that coordination supports the operator's situation understanding. The stable characteristics of teamwork observed across different tasks may indicate that teamwork is performed in a procedural way, and as a strategy to cope with a complex and uncertain situation. The practical lessons learned from the experiment were that the crews managed to learn the work styles with the given training and were able to perform the work style of the experimental conditions. Thus, it is possible to carry out studies of important task management and teamwork issues in HAMMLAB. (Author)

Hypoxia and oxidation levels of DNA and lipids in humans and animal experimental models

DEFF Research Database (Denmark)

Møller, Peter; Risom, Lotte; Lundby, Carsten

2008-01-01

The objective of this review was to evaluate the association between hypoxia and oxidative damage to DNA and lipids. Evaluation criteria encompassed specificity and validation status of the biomarkers, study design, strength of the association, dose-response relationship, biological plausibility......, analogous exposures, and effect modification by intervention. The collective interpretation indicates persuasive evidence from the studies in humans for an association between hypoxia and elevated levels of oxidative damage to DNA and lipids. The levels of oxidatively generated DNA lesions and lipid...... in subjects at high altitude. Most of the animal experimental models should be interpreted with caution because the assays for assessment of lipid peroxidation products have suboptimal validity....

When Does Money Make Money More Important? Survey and Experimental Evidence

OpenAIRE

Sanford E. DeVoe; Jeffrey Pfeffer; Byron Y. Lee

2013-01-01

The authors investigate how the amount and source of income affects the importance placed on money. Using a longitudinal analysis of the British Household Panel Survey and evidence from two laboratory experiments, they found that larger amounts of money received for labor were associated with individuals placing greater importance on money; but this effect did not hold for money not related to work. The longitudinal survey analysis demonstrated these differential effects of the source of inco...

[Overview of indicators in the context of environment and health].

Science.gov (United States)

Tobollik, Myriam; Kabel, Claudia; Mekel, Odile; Hornberg, Claudia; Plaß, Dietrich

2018-06-01

Evidence-based political measures need reliable information about the health status of a population and the determinants affecting health. Here, environment and health indicators can provide helpful additional insights. This article provides an overview of existing indicators in the field of environment and health. There are single indicators and indicator sets describing solely the environment or health as well as some indicators integrating both aspects. The indicator sets cover classical epidemiological indicators but also summary measures of population health, which combine mortality and morbidity as well as simple descriptions of the exposure towards environmental risks. The indicator sets mostly cover water and air quality related aspects. For some of the indicators their influence on health is also presented. Furthermore, environment related health indicators are part of sustainability indicator sets. There are indicators on the international, European, national, and municipal level. All indicator sets aim to support policy-making by advising on measures and setting priorities in the area of environment and health protection. However not all indicators reflect the effect of the environment on health adequately. Therefore, further development of the existing indicators is necessary to reflect current progress (e. g. political needs) and to include new scientific evidence in the field of environment and health. A continuous provision, review, and interpretation of meaningful indicators is required to identify trends and to react to these in order to protect the environment and health. This is necessary to adequately pursue the precautionary principle.

Experimental evidence for multi-pass extraction with a bent crystal

CERN Document Server

Dehning, Bernd; Fidecaro, Giuseppe; Gyr, Marcel; Herr, Werner; Klem, J T; Scandale, Walter; Vuagnin, G; Weisse, E; Weisz, S; Møller, S P; Uggerhøj, Erik; Freund, A; Hustache, R; Carboni, G; Bussa, M P; Tosello, F

1996-01-01

The feasibility of extracting particles from the halo of a circulating proton beam using a bent silicon crystal has been demonstrated experimentally at the SPS for a beam energy of 120 GeV. Presently studies are conducted to understand the extraction mechanisms and the measured efficiencies. In particular the contribution of multi-pass extraction, where the particles can pass through the crystal many times before being channelled and extracted, is investigated. In a recent experiment, using a crystal especially fabricated with a finite amorphous layer on its surface, it has been proven that multi-pass extraction plays an important role. The experiment is described and the implication for further studies are discussed.

Experimental evidence for the physiological role of bacterial luciferase in the protection of cells against oxidative stress.

Science.gov (United States)

Szpilewska, Hanna; Czyz, Agata; Wegrzyn, Grzegorz

2003-11-01

The origin and function of bioluminescence was considered a problematic question of the Charles Darwin theory. Early evolution of bacterial luminescence and its current physiological importance seem to be especially mysterious. Recently, it was proposed that stimulation of DNA repair may be a physiological role for production of light by bacterial cells. On the other hand, it was also proposed that primary role of luminescent systems could be detoxification of the deleterious oxygen derivatives. Although some previous results might suggest that this hypothesis can be correct, until now experimental evidence for such a mechanism operating in bacterial cells and having physiological importance was generally lacking. Here we demonstrate that in the presence of various oxidants (hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and ferrous ions) at certain concentrations in the culture medium, growth of Vibrio harveyi mutants luxA and luxB, but not of the mutant luxD, is severely impaired relative to wild-type bacteria. This deleterious effect of oxidants on the mutants luxA and luxB could be significantly reduced by addition of the antioxidants A-TEMPO or 40H-TEMPO. We conclude that bacterial luciferase may indeed play a physiological role in the protection of cells against oxidative stress.

Endothelial cell proliferation in swine experimental aneurysm after coil embolization.

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Yumiko Mitome-Mishima

Full Text Available After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.

Selective Cooperation in the Supermarket : Field Experimental Evidence for Indirect Reciprocity.

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Lange, Florian; Eggert, Frank

2015-12-01

Numerous laboratory experiments suggest that mechanisms of indirect reciprocity might account for human cooperation. However, conclusive field data supporting the predictions of indirect reciprocity in everyday life situations is still scarce. Here, we attempt to compensate for this lack by examining the determinants of cooperative behavior in a German supermarket. Our methods were as follows: Confederates of the experimenter lined up at the checkout, apparently to buy a single item. As an act of cooperation, the waiting person in front (the potential helper) could allow the confederate to go ahead. By this means, the potential helper could take a cost (additional waiting time) by providing the confederate with a benefit (saved waiting time). We recorded the potential helpers' behavior and the number of items they purchased as a quantitative measure proportional to the confederate's benefit. Moreover, in a field experimental design, we varied the confederates' image by manipulating the item they purchased (beer vs. water). As predicted, the more waiting time they could save, the more likely the confederates were to receive cooperation. This relationship was moderated by the confederates' image. Cost-to-benefit ratios were required to be more favorable for beer-purchasing individuals to receive cooperation. Our results demonstrate that everyday human cooperation can be studied unobtrusively in the field and that cooperation among strangers is selective in a way that is consistent with current models of indirect reciprocity.

Experimental approach towards shell structure at 100Sn and 78Ni

International Nuclear Information System (INIS)

Grawe, H.; Gorska, M.; Fahlander, C.

2000-07-01

The status of experimental approach to 100 Sn and 78 Ni is reviewed. Revised single particle energies for neutrons are deduced for the N=Z=50 shell closure and evidence for low lying I π =2 + and 3 - states is presented. Moderate E2 polarisation charges of 0.1 e and 0.6 e are found to reproduce the experimental data when core excitation of 100 Sn is properly accounted for in the shell model. For the neutron rich Ni region no conclusive evidence for a N=40 subshell is found, whereas firm evidence for the persistence of the N=50 shell at 78 Ni is inferred from the existence of seniority isomers. The disappearance of this isomerism in the mid νg 9/2 shell is discussed. (orig.)

Neuroprotection in Experimental Autoimmune Encephalomyelitis and Progressive Multiple Sclerosis by Cannabis-Based Cannabinoids.

Science.gov (United States)

Pryce, Gareth; Riddall, Dieter R; Selwood, David L; Giovannoni, Gavin; Baker, David

2015-06-01

Multiple sclerosis (MS) is the major immune-mediated, demyelinating, neurodegenerative disease of the central nervous system. Compounds within cannabis, notably Δ9-tetrahydrocannabinol (Δ9-THC) can limit the inappropriate neurotransmissions that cause MS-related problems and medicinal cannabis is now licenced for the treatment of MS symptoms. However, the biology indicates that the endocannabinoid system may offer the potential to control other aspects of disease. Although there is limited evidence that the cannabinoids from cannabis are having significant immunosuppressive activities that will influence relapsing autoimmunity, we and others can experimentally demonstrate that they may limit neurodegeneration that drives progressive disability. Here we show that synthetic cannabidiol can slow down the accumulation of disability from the inflammatory penumbra during relapsing experimental autoimmune encephalomyelitis (EAE) in ABH mice, possibly via blockade of voltage-gated sodium channels. In addition, whilst non-sedating doses of Δ9-THC do not inhibit relapsing autoimmunity, they dose-dependently inhibit the accumulation of disability during EAE. They also appear to slow down clinical progression during MS in humans. Although a 3 year, phase III clinical trial did not detect a beneficial effect of oral Δ9-THC in progressive MS, a planned subgroup analysis of people with less disability who progressed more rapidly, demonstrated a significant slowing of progression by oral Δ9-THC compared to placebo. Whilst this may support the experimental and biological evidence for a neuroprotective effect by the endocannabinoid system in MS, it remains to be established whether this will be formally demonstrated in further trials of Δ9-THC/cannabis in progressive MS.

Evidence for Future Cognition in Animals

Science.gov (United States)

Roberts, William A.

2012-01-01

Evidence concerning the possibility of mental time travel into the future by animals was reviewed. Both experimental laboratory studies and field observations were considered. Paradigms for the study of future anticipation and planning included inhibition of consumption of current food contingent on future receipt of either a larger quantity or…

Does national scale economic and environmental indicators spur logistics performance? Evidence from UK.

Science.gov (United States)

Khan, Syed Abdul Rehman; Qianli, Dong

2017-12-01

The aim of this study is to examine the association between national economic and environmental indicators with green logistics performance in a time series data of UK since 1981 to 2016. The research used autoregressive distributed lag method to understand the long-run and short-run relationships of national scale economic (foreign direct investment (FDI) inflows, per capita income) and environmental indicators (total greenhouse gases, fossil fuel, and renewable energy) on green logistics. In the short run, the research findings indicate that the green logistics and renewable energy have positive relationship, while fossil fuel is negatively correlated with green logistics operations. On the other hand, in the long run, the results show that FDI inflows, renewable energy sources, and per capita income have statistically significant and positive association with green logistics activities, while foreign investments attracted by environmental friendly policies and practices adopted in global logistics operations, which not only increase the environmental sustainability but also enhance economic activities with greater export opportunities in the region.

Prediction of Protein–Protein Interactions by Evidence Combining Methods

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Ji-Wei Chang

2016-11-01

Full Text Available Most cellular functions involve proteins’ features based on their physical interactions with other partner proteins. Sketching a map of protein–protein interactions (PPIs is therefore an important inception step towards understanding the basics of cell functions. Several experimental techniques operating in vivo or in vitro have made significant contributions to screening a large number of protein interaction partners, especially high-throughput experimental methods. However, computational approaches for PPI predication supported by rapid accumulation of data generated from experimental techniques, 3D structure definitions, and genome sequencing have boosted the map sketching of PPIs. In this review, we shed light on in silico PPI prediction methods that integrate evidence from multiple sources, including evolutionary relationship, function annotation, sequence/structure features, network topology and text mining. These methods are developed for integration of multi-dimensional evidence, for designing the strategies to predict novel interactions, and for making the results consistent with the increase of prediction coverage and accuracy.

Experimental and modelling studies of the shape memory properties of amorphous polymer network composites

International Nuclear Information System (INIS)

Arrieta, J S; Diani, J; Gilormini, P

2014-01-01

Shape memory polymer composites (SMPCs) have become an important way to leverage improvements in the development of applications featuring shape memory polymers (SMPs). In this study, an amorphous SMP matrix has been filled with different types of reinforcements. An experimental set of results is presented and then compared to three-dimensional (3D) finite-element simulations. Thermomechanical shape memory cycles were performed in uniaxial tension. The fillers effect was studied in stress-free and constrained-strain recoveries. Experimental observations indicate complete shape recovery and put in evidence the increased sensitivity of constrained length stress recoveries to the heating ramp on the tested composites. The simulations reproduced a simplified periodic reinforced composite and used a model for the matrix material that has been previously tested on regular SMPs. The latter combines viscoelasticity at finite strain and time-temperature superposition. The simulations easily allow representation of the recovery properties of a reinforced SMP. (paper)

Measuring quality of care: considering conceptual approaches to quality indicator development and evaluation.

Science.gov (United States)

Stelfox, Henry T; Straus, Sharon E

2013-12-01

In this article, we describe one approach for developing and evaluating quality indicators. We focus on describing different conceptual approaches to quality indicator development, review one approach for developing quality indicators, outline how to evaluate quality indicators once developed, and discuss quality indicator maintenance. The key steps for developing quality indicators include specifying a clear goal for the indicators; using methodologies to incorporate evidence, expertise, and patient perspectives; and considering contextual factors and logistics of implementation. The Strategic Framework Board and the National Quality Measure Clearinghouse have developed criteria for evaluating quality indicators that complement traditional psychometric evaluations. Optimal strategies for quality indicator maintenance and dissemination have not been determined, but experiences with clinical guideline maintenance may be informative. For quality indicators to effectively guide quality improvement efforts, they must be developed, evaluated, maintained, and implemented using rigorous evidence-informed practices. Copyright © 2013 Elsevier Inc. All rights reserved.

The subclinical form of experimental visceral leishmaniasis in dogs

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G. G. S. Oliveira

1993-06-01

Full Text Available Pathological aspects of a subclinical form of experimental canine leishmaniasis is reported here for the first time. Fifteen mongrel dogs were used in the present study. Eight dogs were infected and seven were used as control. Four of the control dogs were inoculated with spleen cells from non-infected hamsters. The eight mongrel dogs inoculated intravenously with amastigotes forms of Leishmania chagasi envolved for periods as long as 25 months without any clinical characteristic sign of classical Visceral Leishmaniasis (VL. Most of the laboratory test results were compatible to those of the seven control animals but culture of bone marrow aspirated material and serologic testing (IIF demonstrated or provided evidence that the animals were infected. The most important and predominant histopathological lesion in infected animals were epitheloid granulomas presented in the liver, spleen, adrenal gland and lung of some animals. Channels containing erythrocytes in some granulomas of the liver suggeste that these granulomas are formed inside sinusoidal capillaries. Despite the animals were proved to be infected and presented characteristic histologic lesions, they did not present external signs of disease. The granulomatous aspect of the lesions indicates a good immunologic reactivity and suggest that a host-parasite equilibrium does exist in the dog experimental model

A Systematic Review of Socioeconomic Indicators and Dental Caries in Adults

Science.gov (United States)

Costa, Simone M.; Martins, Carolina C.; Bonfim, Maria de Lourdes C.; Zina, Lívia G.; Paiva, Saul M.; Pordeus, Isabela A.; Abreu, Mauro H. N. G.

2012-01-01

Increasing evidence suggests that socioeconomic factors may be associated with an increased risk of dental caries. To provide better evidence of the association between dental caries in adults and socioeconomic indicators, we evaluated the relation between these two conditions in a thorough review of the literature. Seven databases were systematically searched: Pubmed, Cochrane, Web of Science, Bireme, Controlled Trials, Clinical Trials and the National Institute for Health and Clinical Excellence. No restrictions were placed on the language or year of publication. The search yielded 41 studies for systematic review. Two independent reviewers screened the studies for inclusion, extracted data and evaluated quality using the Newcastle-Ottawa scale. The following socioeconomic indicators were found: educational level, income, occupation, socio-economic status and the community index. These indicators were significantly associated with a greater occurrence of dental caries: the subject’s education, subject’s income, subject’s occupation and the Gini coefficient. A high degree of heterogeneity was found among the methods. Quality varied across studies. The criteria employed for socioeconomic indicators and dental caries should be standardized in future studies. The scientific evidence reveals that educational level, income, occupation and the Gini coefficient are associated with dental caries. PMID:23202762

Optimization of Forced Degradation Using Experimental Design and Development of a Stability-Indicating Liquid Chromatographic Assay Method for Rebamipide in Bulk and Tablet Dosage Form

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Sandeep SONAWANE

2016-09-01

Full Text Available A novel stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of rebamipide in bulk and tablet dosage form. Rebamipide (drug and drug product solutions were exposed to acid and alkali hydrolysis, thermal stress, oxidation by hydrogen peroxide and photodegradation. Experimental design has been used during forced degradation to determine significant factors responsible for degradation and to obtain optimal degradation conditions. In addition, acid and alkali hydrolysis was performed using a microwave oven. The chromatographic method employed the HiQ sil C-18HS (250 × 4.6 mm; 5 μm column with mobile phase consisting of 0.02 M potassium phosphate (pH adjusted to 6.8 and methanol (40:60, v/v and the detection was performed at 230 nm. The procedure was validated for specificity, linearity, accuracy, precision and robustness. There was no interference observed of excipients and degradation products in the determination of the active pharmaceutical ingredient. The method showed good accuracy and precision (intra and inter day and the response was linear in a range from 0.5 to 5 μg mL−1. The method was found to be simple and fast with less trial and error experimentation by making use of experimental design. Also, it proved that microwave energy can be used to expedite hydrolysis of rebamipide.

EXPERIMENTAL EVIDENCE FOR HOMING IN THE RED SWAMP CRAYFISH, PROCAMBARUS CLARKII

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BARBARESI S.

2006-01-01

Full Text Available The red swamp crayfish, Procambarus clarkii, is an efficient burrower, but its burrow fidelity has been recently questioned. In this study, we aimed at investigating whether individuals of this species are capable to learn the position of a goal (a wet burrow hidden to their sight in experimental tanks and to make more efficient with time their oriented movement towards it. We also analyzed crayfish behavior after having closed one of the two accesses to the goal. Indeed, in successive trials we recorded the crayfish tendency to reduce the distance covered to reach the goal and the time taken, except when they were already familiar to the experimental setting. Memory of the spatial configuration lasted for 16 hours at least and crayfish learned and maintained individual trajectories. The interruption of their usual path always caused a drastic increase of distance and time that however decreased in the successive trials. This study provided also some information of the sensory channels used by P. clarkii to orient. This crayfish, which can be active also during daytime, seemed to adopt a combination of tactile and visual information, together with the possible use of cues (i.e. humidity cues emitted by the goal. Future studies should clarify the paradox of a crayfish species whose individuals, although being physiologically capable to home, seem not to return to the previously occupied burrows at the end of their foraging excursions, notwithstanding the time and energy expended to excavate them.

Benzodiazepines, opioids and driving: an overview of the experimental research.

Science.gov (United States)

Leung, Stefanie Y

2011-05-01

Road crashes contribute significantly to the total burden of injury in Australia, with the risk of injury being associated with the presence of drugs and/or alcohol in the driver's blood. Increasingly, some of the most commonly detected drugs include prescription medicines, the most notable of these being benzodiazepines and opioids. However, there is a paucity of experimental research into the effects of prescribed psychoactive drugs on driving behaviours. This paper provides an overview of experimental studies investigating the effects of prescribed doses of benzodiazepines and opioids on driving ability, and points to future directions for research. There is growing epidemiological evidence linking the therapeutic use of benzodiazepines and opioids to an increased crash risk. However, the current experimental literature remains unclear. Limitations to study methodologies have resulted in inconsistent findings. Limited experimental evidence exists to inform policy and guidelines regarding fitness-to-drive for patients taking prescribed benzodiazepines and opioids. Further experimental research is required to elucidate the effects of these medications on driving, under varying conditions and in different medical contexts. This will ensure that doctors prescribing benzodiazepines and opioids are well informed, and can appropriately advise patients of the risks associated with driving whilst taking these medications. © 2011 Australasian Professional Society on Alcohol and other Drugs.

Apex Dips of Experimental Flux Ropes: Helix or Cusp?

Energy Technology Data Exchange (ETDEWEB)

Wongwaitayakornkul, Pakorn; Haw, Magnus A.; Bellan, Paul M. [Applied Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Li, Hui [Theoretical Division, Los Alamos National Laboratory, Mail Stop B227, Los Alamos, NM 87545 (United States); Li, Shengtai, E-mail: pwongwai@caltech.edu, E-mail: mhaw@caltech.edu [Mathematical Modeling and Analysis, Los Alamos National Laboratory, Mail Stop B284, Los Alamos, NM 87545 (United States)

2017-10-20

We present a new theory for the presence of apex dips in certain experimental flux ropes. Previously such dips were thought to be projections of a helical loop axis generated by the kink instability. However, new evidence from experiments and simulations suggest that the feature is a 2D cusp rather than a 3D helix. The proposed mechanism for cusp formation is a density pileup region generated by nonlinear interaction of neutral gas cones emitted from fast-gas nozzles. The results indicate that density perturbations can result in large distortions of an erupting flux rope, even in the absence of significant pressure or gravitational forces. The density pileup at the apex also suppresses the m = 1 kink mode by acting as a stationary node. Consequently, more accurate density profiles should be considered when attempting to model the stability and shape of solar and astrophysical flux ropes.

User preferences and willingness to pay for safe drinking water: Experimental evidence from rural Tanzania.

Science.gov (United States)

Burt, Zachary; Njee, Robert M; Mbatia, Yolanda; Msimbe, Veritas; Brown, Joe; Clasen, Thomas F; Malebo, Hamisi M; Ray, Isha

2017-01-01

Almost half of all deaths from drinking microbiologically unsafe water occur in Sub-Saharan Africa. Household water treatment and safe storage (HWTS) systems, when consistently used, can provide safer drinking water and improve health. Social marketing to increase adoption and use of HWTS depends both on the prices of and preferences for these systems. This study included 556 households from rural Tanzania across two low-income districts with low-quality water sources. Over 9 months in 2012 and 2013, we experimentally evaluated consumer preferences for six "low-cost" HWTS options, including boiling, through an ordinal ranking protocol. We estimated consumers' willingness to pay (WTP) for these options, using a modified auction. We allowed respondents to pay for the durable HWTS systems with cash, chickens or mobile money; a significant minority chose chickens as payment. Overall, our participants favored boiling, the ceramic pot filter and, where water was turbid, PuR™ (a combined flocculant-disinfectant). The revealed WTP for all products was far below retail prices, indicating that significant scale-up may need significant subsidies. Our work will inform programs and policies aimed at scaling up HWTS to improve the health of resource-constrained communities that must rely on poor-quality, and sometimes turbid, drinking water sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surface physics : experimental

International Nuclear Information System (INIS)

Padalia, B.D.

1978-01-01

In this report, discussion is confined to some important ultra high vacuum surface techniques such as ultra-violet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and the low energy electron diffraction (LEED). An attempt is made to cover the basic principles and the experimental details of XPS and AES. Selected examples illustrating the potentialities of the above techniques to solve the important basic as well as applied problems relating to surfaces are presented. Salient features of the available commercial machines in which UPS, AES and LEED are combined to facilitate surface examination sequentially or simultaneously under identical experimental conditions are indicated. (auth.)

Experimental constraints on theories of high Tc superconductors

International Nuclear Information System (INIS)

Little, W.A.

1989-01-01

Recent experiments on the high-T c superconductors have begun to narrow the possible theoretical explanations of the phenomenon. Experimental evidence on the size, structure and symmetry of the charge carriers will be reviewed; evidence for and against strong coupling; and, recent results on a search for direct evidence of magnetic signature in the coupling mechanism will be presented. The authors show how these experiments impose strong constraints on the theories of these superconductors. A new type of experiment is also discussed which appears capable of identifying the true nature of the coupling mechanism if the superconductors prove to be BCS-like in nature

Skin care for healthy babies at term: A systematic review of the evidence.

Science.gov (United States)

Cooke, Alison; Bedwell, Carol; Campbell, Malcolm; McGowan, Linda; Ersser, Steven J; Lavender, Tina

2018-01-01

to identify what skin practices are important for the protection of baby skin in healthy term babies (0-6 months) and generate evidence-based conclusions to inform health professionals and parents. eleven databases were searched for all empirical quantitative and qualitative research published between 2000-2015 which explored baby skin care for bathing and cleansing, nappy care, hair and scalp care, management of dry skin or baby massage, for healthy term babies up to 6 months old. Papers not published in English were excluded. A total of 3062 papers were identified. Pairs of reviewers assessed all citations and extracted data independently. There were 26 included papers: 16 RCTs, 3 non-randomised experimental studies, 1 mixed-methods study and 6 qualitative studies. Primary and secondary outcome measures were analysed using meta-analysis or narrative descriptive statistics. Synthesis of qualitative data was not possible due to disparity of the evidence. from the small numbers of studies with comparable data, there was no evidence of any significant differences between tested wash products and water or tested baby wipes and water. There was some evidence to suggest that daily use of full-body emollient therapy may help to reduce the risk of atopic eczema in high risk babies with a genetic predisposition to eczema; however, the use of olive oil or sunflower oil for baby dry skin may adversely affect skin barrier function. There was no evidence about hair/scalp care or baby massage. Qualitative research indicates that parents and health professionals believe that water alone is best. meta-analysis was restricted due to the lack of consistency of study outcome measures. Although there is considerable RCT evidence comparing the use of specific products against water alone, or another product, for bathing, cleansing and nappy care, the power of this evidence is reduced due to inconsistency of outcome measures in terms of outcome, treatment site or time-point. The

Overstated evidence for short-term effects of violent games on affect and behavior: A reanalysis of Anderson et al. (2010).

Science.gov (United States)

Hilgard, Joseph; Engelhardt, Christopher R; Rouder, Jeffrey N

2017-07-01

Violent video games are theorized to be a significant cause of aggressive thoughts, feelings, and behaviors. Important evidence for this claim comes from a large meta-analysis by Anderson and colleagues (2010), who found effects of violent games in experimental, cross-sectional, and longitudinal research. In that meta-analysis, the authors argued that there is little publication or analytic bias in the literature, an argument supported by their use of the trim-and-fill procedure. In the present manuscript, we reexamine their meta-analysis using a wider array of techniques for detecting bias and adjusting effect sizes. Our conclusions differ from those of Anderson and colleagues in 3 salient ways. First, we detect substantial publication bias in experimental research on the effects of violent games on aggressive affect and aggressive behavior. Second, after adjustment for bias, the effects of violent games on aggressive behavior in experimental research are estimated as being very small, and estimates of effects on aggressive affect are much reduced. In contrast, the cross-sectional literature finds correlations that appear largely unbiased. Third, experiments meeting the original authors' criteria for methodological quality do not yield larger adjusted effects than other experiments, but instead yield larger indications of bias, indicating that perhaps they were selected for significance. We outline future directions for stronger experimental research. The results indicate the need for an open, transparent, and preregistered research process to test the existence of the basic phenomenon. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Mechanical Performance versus Corrosion Damage Indicators for Corroded Steel Reinforcing Bars

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Silvia Caprili

2015-01-01

Full Text Available The experimental results of a testing campaign including tensile and low-cycle fatigue tests on different reinforcing steel bar types in the as-delivered and corroded condition are presented. Experimental data were statistically analyzed adopting ANOVA technique; Performance Indicators (PIs, describing the mechanical performance characteristics of reinforcements, and Corrosion Damage Indicators (CDIs, describing the detrimental effects of corrosion phenomena, were determined and correlated in order to evaluate the influence of corrosion on the behaviour of reinforcing steels, providing useful information for designers in addition to what is presented in current standards.

Review: Alterations in placental glycogen deposition in complicated pregnancies: Current preclinical and clinical evidence.

Science.gov (United States)

Akison, Lisa K; Nitert, Marloes Dekker; Clifton, Vicki L; Moritz, Karen M; Simmons, David G

2017-06-01

Normal placental function is essential for optimal fetal growth. Transport of glucose from mother to fetus is critical for fetal nutrient demands and can be stored in the placenta as glycogen. However, the function of this glycogen deposition remains a matter of debate: It could be a source of fuel for the placenta itself or a storage reservoir for later use by the fetus in times of need. While the significance of placental glycogen remains elusive, mounting evidence indicates that altered glycogen metabolism and/or deposition accompanies many pregnancy complications that adversely affect fetal development. This review will summarize histological, biochemical and molecular evidence that glycogen accumulates in a) placentas from a variety of experimental rodent models of perturbed pregnancy, including maternal alcohol exposure, glucocorticoid exposure, dietary deficiencies and hypoxia and b) placentas from human pregnancies with complications including preeclampsia, gestational diabetes mellitus and intrauterine growth restriction (IUGR). These pregnancies typically result in altered fetal growth, developmental abnormalities and/or disease outcomes in offspring. Collectively, this evidence suggests that changes in placental glycogen deposition is a common feature of pregnancy complications, particularly those associated with altered fetal growth. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Experimental probes of emergent symmetries in the quantum Hall system

CERN Document Server

Lutken, C A

2011-01-01

Experiments studying renormalization group flows in the quantum Hall system provide significant evidence for the existence of an emergent holomorphic modular symmetry Gamma(0)(2). We briefly review this evidence and show that, for the lowest temperatures, the experimental determination of the position of the quantum critical points agrees to the parts per mille level with the prediction from Gamma(0)(2). We present evidence that experiments giving results that deviate substantially from the symmetry predictions are not cold enough to be in the quantum critical domain. We show how the modular symmetry extended by a non-holomorphic particle hole duality leads to an extensive web of dualities related to those in plateau insulator transitions, and we derive a formula relating dual pairs (B, B(d)) of magnetic field strengths across any transition. The experimental data obtained for the transition studied so far is in excellent agreement with the duality relations following from this emergent symmetry, and rule out...

The Feeling of Agency: Empirical Indicators for a Pre-Reflective Level of Action Awareness

Science.gov (United States)

David, Nicole; Stenzel, Anna; Schneider, Till R.; Engel, Andreas K.

2011-01-01

The sense of agency has been defined as the sense that I am the author of my own actions. This sense, however, is usually not reflected upon but instead pre-reflectively experienced. Experimental approaches usually measure the sense of agency by judgments or verbal reports, despite evidence that the sense of agency is not sufficiently assessed on such a reflective level. Here we sought to identify non-verbal measures of the sense of agency, particularly testing the relevance of physiological activity such as skin conductance and heart rate. Manipulating the visual feedback to an executed movement, we investigated how well physiological activity and other movement parameters differed between real and false feedback (i.e., between actual agency and non-agency), and how they related to accuracy of agency judgments. Skin conductance and heart rate did not differ between agency and non-agency situations; neither did they inform agency judgments. In contrast, movement onsets – particularly, discrepancies between feedback and movement onsets – were related to agency judgments. Overall, our results indicate weak visceral–somatic associations with the sense of agency. Thus, physiological activity did not prove to be an empirical indicator for the feeling of agency. PMID:21779268

Experimental evidence for negative turgor pressure in small leaf cells of Robinia pseudoacacia L versus large cells of Metasequoia glyptostroboides Hu et W.C.Cheng. 1. Evidence from pressure-volume curve analysis of dead tissue.

Science.gov (United States)

Yang, Dongmei; Pan, Shaoan; Ding, Yiting; Tyree, Melvin T

2017-03-01

This paper provides a mini-review of evidence for negative turgor pressure in leaf cells starting with experimental evidence in the late 1950s and ending with biomechanical models published in 2014. In the present study, biomechanical models were used to predict how negative turgor pressure might be manifested in dead tissue, and experiments were conducted to test the predictions. The main findings were as follows: (i) Tissues killed by heating to 60 or 80 °C or by freezing in liquid nitrogen all became equally leaky to cell sap solutes and all seemed to pass freely through the cell walls. (ii) Once cell sap solutes could freely pass the cell walls, the shape of pressure-volume curves was dramatically altered between living and dead cells. (iii) Pressure-volume curves of dead tissue seem to measure negative turgor defined as negative when inside minus outside pressure is negative. (iv) Robinia pseudoacacia leaves with small palisade cells had more negative turgor than Metasequoia glyptostroboides with large cells. (v) The absolute difference in negative turgor between R. pseudoacacia and M. glyptostroboides approached as much as 1.0 MPa in some cases. The differences in the manifestation of negative turgor in living versus dead tissue are discussed. © 2016 John Wiley & Sons Ltd.

Nitrate ammonification by Nautilia profundicola AmH: experimental evidence consistent with a free hydroxylamine intermediate.

Directory of Open Access Journals (Sweden)

Thomas E Hanson

2013-07-01

Full Text Available The process of nitrate reduction via nitrite controls the fate and bioavailability of mineral nitrogen within ecosystems; i.e. whether it is retained as ammonium (ammonification or lost as nitrous oxide or dinitrogen (denitrification. Here, we present experimental evidence for a novel pathway of microbial nitrate reduction, the reverse hydroxylamine:ubiquinone reductase module (reverse-HURM pathway. Instead of a classical ammonia-forming nitrite reductase that performs a 6 electron-transfer process, the pathway is thought to employ two catalytic redox modules operating in sequence: the reverse-HURM reducing nitrite to hydroxylamine followed by a hydroxylamine reductase that converts hydroxylamine to ammonium. Experiments were performed on Nautilia profundicola strain AmH, whose genome sequence led to the reverse-HURM pathway proposal. N. profundicola produced ammonium from nitrate, which was assimilated into biomass. Furthermore, genes encoding the catalysts of the reverse-HURM pathway were preferentially expressed during growth of N. profundicola on nitrate as an electron acceptor relative to cultures grown on polysulfide as an electron acceptor. Finally, nitrate-grown cells of N. profundicola were able to rapidly and stoichiometrically convert high concentrations of hydroxylamine to ammonium in resting cell assays. These experiments are consistent with the reverse-HURM pathway and a free hydroxylamine intermediate, but could not definitively exclude direct nitrite reduction to ammonium by the reverse-HURM with hydroxylamine as an off-pathway product. N. profundicola and related organisms are models for a new pathway of nitrate ammonification that may have global impact due to the wide distribution of these organisms in hypoxic environments and symbiotic or pathogenic associations with animal hosts.

Evaluating the Impact of an Accountable Care Organization on Population Health: The Quasi-Experimental Design of the German Gesundes Kinzigtal.

Science.gov (United States)

Pimperl, Alexander; Schulte, Timo; Mühlbacher, Axel; Rosenmöller, Magdalena; Busse, Reinhard; Groene, Oliver; Rodriguez, Hector P; Hildebrandt, Helmut

2017-06-01

A central goal of accountable care organizations (ACOs) is to improve the health of their accountable population. No evidence currently links ACO development to improved population health. A major challenge to establishing the evidence base for the impact of ACOs on population health is the absence of a theoretically grounded, robust, operationally feasible, and meaningful research design. The authors present an evaluation study design, provide an empirical example, and discuss considerations for generating the evidence base for ACO implementation. A quasi-experimental study design using propensity score matching in combination with small-scale exact matching is implemented. Outcome indicators based on claims data were constructed and analyzed. Population health is measured by using a range of mortality indicators: mortality ratio, age at time of death, years of potential life lost/gained, and survival time. The application is assessed using longitudinal data from Gesundes Kinzigtal, one of the leading population-based ACOs in Germany. The proposed matching approach resulted in a balanced control of observable differences between the intervention (ACO) and control groups. The mortality indicators used indicate positive results. For example, 635.6 fewer years of potential life lost (2005.8 vs. 2641.4; t-test: sig. P < 0.05*) in the ACO intervention group (n = 5411) attributable to the ACO, also after controlling for a potential (indirect) immortal time bias by excluding the first half year after enrollment from the outcome measurement. This empirical example of the impact of a German ACO on population health can be extended to the evaluation of ACOs and other integrated delivery models of care.

Key performance indicators in intensive care medicine. A retrospective matched cohort study.

Science.gov (United States)

Kastrup, M; von Dossow, V; Seeling, M; Ahlborn, R; Tamarkin, A; Conroy, P; Boemke, W; Wernecke, K-D; Spies, Claudia

2009-01-01

Expert panel consensus was used to develop evidence-based process indicators that were independent risk factors for the main clinical outcome parameters of length of stay in the intensive care unit (ICU) and mortality. In a retrospective, matched data analysis of patients from five ICUs at a tertiary university hospital, agreed process indicators (sedation monitoring, pain monitoring, mean arterial pressure [MAP] >or= 60 mmHg, tidal volume [TV] or= 80 and or= 60 mmHg and BG >or= 80 mg/dl were relevant for survival. Linear regression of the 634 patients showed that analgesia monitoring, PIP or= 60 mmHg, BG >or= 80 mg/dl and indicating that adherence to evidence-based key process indicators may reduce mortality and length of ICU stay.

Wundt, Völkerpsychologie, and experimental social psychology.

Science.gov (United States)

Greenwood, John D

2003-02-01

Wilhelm Wundt distinguished between "experimental psychology" and Volkerpsychologie. It is often claimed that Wundt maintained that social psychological phenomena, the subject matter of Völkerpsychologie, could not be investigated experimentally but must be explored via comparative-historical methods. In this article it is argued that it is doubtful if many of the passages usually cited as evidence that Wundt held such a view actually such such a view. It is also argued that if Wundt did hold such a view, it was inconsistent with his own general theoretical position and methodological practice. It is suggested that it is anachronistic to attribute such a view to Wundt, because he appears to have had little interest in the experimental analysis of the synchronic social dynamics of psychological processes. Most of Wundt's arguments about the inappropriateness of experimentation were directed against the introspective analysis of diachronic historical processes.

An Experimental Framework for Generating Evolvable Chemical Systems in the Laboratory

Science.gov (United States)

Baum, David A.; Vetsigian, Kalin

2017-12-01

Most experimental work on the origin of life has focused on either characterizing the chemical synthesis of particular biochemicals and their precursors or on designing simple chemical systems that manifest life-like properties such as self-propagation or adaptive evolution. Here we propose a new class of experiments, analogous to artificial ecosystem selection, where we select for spontaneously forming self-propagating chemical assemblages in the lab and then seek evidence of a response to that selection as a key indicator that life-like chemical systems have arisen. Since surfaces and surface metabolism likely played an important role in the origin of life, a key experimental challenge is to find conditions that foster nucleation and spread of chemical consortia on surfaces. We propose high-throughput screening of a diverse set of conditions in order to identify combinations of "food," energy sources, and mineral surfaces that foster the emergence of surface-associated chemical consortia that are capable of adaptive evolution. Identification of such systems would greatly advance our understanding of the emergence of self-propagating entities and the onset of adaptive evolution during the origin of life.

When culture does not matter: Experimental evidence from coalition formation ultimatum games in Austria and Japan

NARCIS (Netherlands)

Okada, A.; Riedl, A.M.

1999-01-01

This paper reports the results of a cross-country comparison between Austria andJapan for an experimental 3-personcoalition formation ultimatum game. The experimental design allows thecomparison with respect to three decisions. (i)The coalition decision, (ii) proposers' demand behavior in 2- and

ANTHROPOGENIC POLLEN INDICATORS (API FROM ARCHAEOLOGICAL SITES AS LOCAL EVIDENCE OF HUMAN-INDUCED ENVIRONMENTS IN THE ITALIAN PENINSULA

Directory of Open Access Journals (Sweden)

A. M. Mercuri

2013-04-01

Full Text Available Pollen data from twenty-six archaeological sites are reviewed to investigate the development of human-induced environments through the presence of selected Anthropogenic Pollen Indicators (API. The sites are located in six Italian regions - Veneto, Emilia Romagna, Tuscany, Basilicata, Calabria, and Sicily - and in the Republic of San Marino. Their chronology spans from the Bronze to the Renaissance ages, from approximately 4200 to 500 years BP. The API which are common in these sites are properly considered important markers of human activity and anthropization in the Mediterranean area. The most frequent API taxa in pollen spectra are seven: Artemisia, Centaurea, Cichorieae and Plantago are ubiquitous and therefore they have the major relevance, followed by cereals and Urtica, and by Trifolium type. The spread of plants producing these pollen grains is sometimes marked by high percentage values in pollen spectra. Pollen records show that, as expected, cereals and wild synanthropic herbs were widespread near archaeological sites but local differences are evident. Ecological and chrono-cultural reasons may be at the base of the observed differences. In general, the synanthropic plants well represent the xeric environments that developed as a result of the continuous human pressure and changes in soil compositions. These changes have occurred especially during the mid and late Holocene.

An experimental and analytical investigation of glow plug performance in ignition and flame propagation through low concentrations of H2 in a steam/fog environment

International Nuclear Information System (INIS)

Davis, B.W.

1982-01-01

Thermal igniters proposed by the Tennessee Valley Authority for intentional ignition of hydrogen in nuclear reactor containments have been tested in mixtures of air, hydrogen, and steam. The igniters, conventional diesel engine glow plugs, were tested in a 10.6 ft 3 pressure vessel with dry hydrogen concentrations from 4% to 29%, and in steam fractions of up to 50%. Dry tests indicated complete combustion consistently occurred at H 2 fractions above 8% with no combustion for concentrations below 5%. Combustion tests in the presence of steam were conducted with hydrogen volume fractions of 8%, 10%, and 12%. Steam concentrations of up to 30% consistently resulted in ignition. Most of the 40% steam fraction tests indicated a pressure rise. Circulation of the mixture improved combustion in both the dry and the steam tests, most notably at low H 2 concentrations. An analysis of the high steam fraction test data yielded evidence of the presence of small, suspended, water droplets in the combustion mixture. The suppressive influence of condensation-generated fog on combustion is evaluated. Analysis of experimental results along with results derived from analytic models have provided consistent evidence of the strong influence of mass condensation rates and fog on experimentally observed ignition and flame propagation phenomena

Experimental evidence for excess entropy discontinuities in glass-forming solutions.

Science.gov (United States)

Lienhard, Daniel M; Zobrist, Bernhard; Zuend, Andreas; Krieger, Ulrich K; Peter, Thomas

2012-02-21

Glass transition temperatures T(g) are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO(3))(2)), malonic acid, raffinose, and ammonium bisulfate (NH(4)HSO(4)) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T(g) of multi-component systems can be predicted using mixing rules. However, the experimentally observed T(g) in multi-component solutions show considerable deviations from two theoretical approaches considered. The deviations from these predictions are explained in terms of the molar excess mixing entropy difference between the supercooled liquid and glassy state at T(g). The multi-component mixtures involve contributions to these excess mixing entropies that the mixing rules do not take into account. © 2012 American Institute of Physics

Climate warming drives local extinction: Evidence from observation and experimentation.

Science.gov (United States)

Panetta, Anne Marie; Stanton, Maureen L; Harte, John

2018-02-01

Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant ( Androsace septentrionalis ). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues.

Evaluation of DOE radionuclide solubility data and selected retardation parameters: description of calculational and confirmatory experimental activities

International Nuclear Information System (INIS)

Kelmers, A.D.; Clark, R.J.; Cutshall, N.H.; Johnson, J.S.; Kessler, J.H.

1983-01-01

An experimentally oriented program has been initiated to support the NRC analysis and licensing activities related to high-level nuclear waste repositories. The program will allow the NRC to independently confirm key geochemical values used in the site performance assessments submitted by the DOE candidate repository site projects. Key radionuclide retardation factor values, particularly radionuclide solubility and sorption values under site specific geochemical conditions, are being confirmed. The initial efforts are being directed toward basalt rock/groundwater systems relevant to the BWIP candidate site in the Pasco Basin. Future work will consider tuff (NNWSI candidate site in Yucca Mountain) and salt (unspecified ONWI bedded or domal salt sites) rock/groundwater systems. Initial experimental results with technetium have confirmed the BWIP values for basalt/groundwater systems under oxic redox conditions: high solubility and no sorption. Under reducing redox conditions, however, the experimental work did not confirm the proposed technetium values recommended by BWIP. In the presence of hydrazine to establish reducing conditions, an apparent solubility limit for technetium of about 5E-7 mol/L was encountered; BWIP recommended calculated values of 1E-12 or greater than or equal to 1E-14 mol/L. Experimental evidence concerning sorption of reduced technetium species is incomplete at this time. Equilibrium speciation and saturation indices were calculated for well water data sets from BWIP using the computer code PHREEQUE. Oversaturation was indicated for hematite and quartz in all data sets. Near surface samples were undersaturated with respect to calcite, but most deep samples were oversaturated with respect to calcite and other carbonate minerals

Peculiarities of changes in indices of immunological reactivity in experimental allergic alveolitis under adrenalin myocardial injury and their correction with thiotriazoline

Directory of Open Access Journals (Sweden)

Volodymyr Pyndus

2015-10-01

  Abstract Allergic diseases cover more than 20% of people living on the earth, among who exogenous allergic alveolitis (AA occupies a prominent place. However, the frequency of this disease increases and there is a number of complications with not only medical but also socio-economic values. Today the question remains to be not studied that concerns changes of selected indicators of clinical and humoral immunity in the blood for experimental allergic alveoli (EAA and adrenaline myocardial injury (AMI and the possibility of their correction with antioxidants. The goal of study was to elucidate peculiarities of changes of immunological reactivity in the EAA in terms of AMI and set the effect of  thiotriazoline on them. The study of individual markers of cellular and humoral immunity showed a malfunction of the immune system in the formation of EAA and AMI and set monocristalline the effect of thiotriazolin on the level of T and B-lymphocytes and  CIC in blood.   Key words: experimental allergic alveolitis, adrenaline myocardial injury, thiotriazolin. Ключові слова: експериментальний алергічний альвеоліт, адреналінове пошкодження міокарда, тіотриазолін.

Validating operational food insecurity indicators against a dynamic benchmark : evidence from Mali

OpenAIRE

Christiaensen, Luc J.; Boisvert, Richard N.; Hoddinott, John

2000-01-01

The authors develop an explicitly forward-looking indicator of food insecurity that takes into account both current dietary inadequacy and vulnerability to dietary inadequacy in the future. Application of this measure to data from northern Mali shows that neglecting the future dimension of food insecurity causes serious underestimation of food insecurity in this area. The authors evaluate ...

Lessons learnt from experimental temporary octopus fishing ...

African Journals Online (AJOL)

This paper presents evidence of the fisheries effect of experimental temporary fishing closures for Octopus in the then-emergent Velondriake Locally Managed Marine Area (LMMA) in south-west Madagascar during 2004–2006. We present an analysis of the O. cyanea catch data for the first two years of temporary closures ...

Evidence-Based Advances in Reptile Medicine.

Science.gov (United States)

Mitchell, Mark A; Perry, Sean M

2017-09-01

Evidence-based medicine allows veterinarians to practice high-quality medicine, because the basis for all decision making is quantitative, objective, and reproducible. Case reports and case series are limited in their scope and application. Cross-sectional studies, likewise, cannot provide answers to specific variable testing with a temporal application. It is essential for the reptile specialty to expand into case-control studies, cohort studies, and experimental/intervention studies. Unfortunately, much of the reptile literature remains limited to descriptive studies. This article reviews current evidence-based topics in reptile medicine and shares how everyone practicing in the field can contribute to improving this specialty. Copyright © 2017 Elsevier Inc. All rights reserved.

Hadronic collision and hadronic structure (an experimental review)

International Nuclear Information System (INIS)

Davier, M.

1975-01-01

In this set of lectures an attempt is made to present a survey of the available experimental data on hadronic collisions at large transverse momentum, together with their current phenomenological descriptions. In particular, the experimental confirmation of constituent structure is looked at in a critical way. The emphasis throughout is to let the data speak in the most unbiased way and to gather evidence as to the short range structure of the hadronic interactions. Finally the current information on lepton production in hadronic collisions is reviewed

Sustainability of Evidence-Based Acute Pain Management Practices for Hospitalized Older Adults.

Science.gov (United States)

Shuman, Clayton J; Xie, Xian-Jin; Herr, Keela A; Titler, Marita G

2017-11-01

Little is known regarding sustainability of evidence-based practices (EBPs) following implementation. This article reports sustainability of evidence-based acute pain management practices in hospitalized older adults following testing of a multifaceted Translating Research Into Practice (TRIP) implementation intervention. A cluster randomized trial with follow-up period was conducted in 12 Midwest U.S. hospitals (six experimental, six comparison). Use of evidence-based acute pain management practices and mean pain intensity were analyzed using generalized estimating equations across two time points (following implementation and 18 months later) to determine sustainability of TRIP intervention effects. Summative Index scores and six of seven practices were sustained. Experimental and comparison group differences for mean pain intensity over 72 hours following admission were sustained. Results revealed most evidence-based acute pain management practices were sustained for 18 months following implementation. Further work is needed to identify factors affecting sustainability of EBPs to guide development and testing of sustainability strategies.

Point-counterpoint in physics: theoretical prediction and experimental discovery of elementary particles

International Nuclear Information System (INIS)

Leite Lopes, J.

1984-01-01

A report is given on the theoretical prediction and the experimental discovery of elementary particles from the electron to the weak intermediate vector bosons. The work of Lattes, Occhialini and Powell which put in evidence the pions predicted by Yukawa was the starting point of the modern experimental particle physics

A TECHNIQUE OF EXPERIMENTAL INVESTIGATIONS OF LINEAR IMPULSE ELECTROMECHANICAL CONVERTERS

Directory of Open Access Journals (Sweden)

V.F. Bolyukh

2017-04-01

Full Text Available Purpose. Development of a technique of experimental studies linear pulse electromechanical converters parameters, which are used as shock-power devices and electromechanical accelerators, and comparing the experimental results with the calculated indices obtained using the mathematical model. Methodology. Method of experimental investigations of linear electromechanical converter is that the electrical parameters are recorded simultaneously (inductor winding current and mechanical parameters characterizing the power and speed indicators of the joke with actuator. Power indicators are primarily important for shock-power devices, and high velocity - for electromechanical accelerators. Power indices were investigated using piezoelectric sensors, a system of strain sensors, pressure pulsation sensor and high-speed videorecording. Velocity indicators were investigated using a resistive movement sensor which allows to record character of the armature movement with actuating element in each moment. Results. The technique of experimental research, which is the simultaneous recording of electrical and mechanical power and velocity parameters of the linear electromechanical converter pulse, is developed. In the converter as a shock-power device power indicators are recorded using a piezoelectric transducer, strain sensors system, pressure pulsation sensor and high-speed video. The parameters of the inductor winding current pulse, the time lag of mechanical processes in relation to the time of occurrence of the inductor winding current, the average speed of the joke, the magnitude and momentum of electrodynamics forces acting on the plate strikes are experimentally determined. In the converter as an electromechanical accelerator velocity performance recorded using resistive displacement sensors. It is shown that electromechanical converter processes have complex spatial-temporal character. The experimental results are in good agreement with the calculated

Blood flow rate measurements with indicator techniques revisited

DEFF Research Database (Denmark)

Sejrsen, Per; Bülow, Jens

2009-01-01

In view of the emerging role, disturbances in regional blood flow rate seem to play in the pathogenesis of the metabolic syndrome; we review the concepts of the classical indicator dilution and washout techniques used for determinations of regional blood flow rate. Prerequisites, assumptions......, necessary precautions for the application of these experimental techniques are emphasized. Special attention has been carried out to elucidate the consequence of a choice of indicators having a large distribution volume in the tissues....

In vivo evidence for a functional role of both tumor necrosis factor (TNF) receptors and transmembrane TNF in experimental hepatitis.

Science.gov (United States)

Küsters, S; Tiegs, G; Alexopoulou, L; Pasparakis, M; Douni, E; Künstle, G; Bluethmann, H; Wendel, A; Pfizenmaier, K; Kollias, G; Grell, M

1997-11-01

The significance of tumor necrosis factor receptor 1 (TNFR1) for TNF function in vivo is well documented, whereas the role of TNFR2 so far remains obscure. In a model of concanavalin A (Con A)-induced, CD4+ T cell-dependent experimental hepatitis in mice, in which TNF is a central mediator of apoptotic and necrotic liver damage, we now provide evidence for an essential in vivo function of TNFR2 in this pathophysiological process. We demonstrate that a cooperation of TNFR1 and TNFR2 is required for hepatotoxicity as mice deficient of either receptor were resistant against Con A. A significant role of TNFR2 for Con A-induced hepatitis is also shown by the enhanced sensitivity of transgenic mice overexpressing the human TNFR2. The ligand for cytotoxic signaling via both TNF receptors is the precursor of soluble TNF, i.e. transmembrane TNF. Indeed, transmembrane TNF is sufficient to mediate hepatic damage, as transgenic mice deficient in wild-type soluble TNF but expressing a mutated nonsecretable form of TNF developed inflammatory liver disease.

The Pay-What-You-Want game: What can be learned from the experimental evidence on Dictator and Trust Games?

Directory of Open Access Journals (Sweden)

Greiff Matthias

2017-03-01

Full Text Available This paper introduces the Pay-What-You-Want game which represents the interaction between a buyer and a seller in a Pay-What-You-Want (PWYW situation. The PWYW game embeds the dictator game and the trust game as subgames. This allows us to use previous experimental studies with the dictator and the trust game to identify three factors that can influence the success of PWYW pricing in business practice: (i social context, (ii social information, and (iii deservingness. Only few cases of PWYW pricing for a longer period of time have been documented. By addressing repeated games, we isolate two additional factors which are likely to contribute to successful implementations of PWYW as a long term pricing strategy. These are (iv communication and (v the reduction of goal conflicts. The central contribution of this study is an attempt to bridge the gap between laboratory experiments and the research on PWYW pricing, which relies largely on evidence from the field. By reviewing the relevant experiments, this study identifies factors crucial for the success of PWYW pricing and provides guidance to developing long-term applications of PWYW pricing.

Building evaluative culture in community services: Caring for evidence.

Science.gov (United States)

Mayne, John

2017-05-25

An organization with a strong evaluative culture engages in self-reflection, evidence-based learning and experimentation. It sees evidence as essential for managing well, but building such a culture is challenging. Community service organizations seek to provide effective services for their clients. To build an evaluative culture, they need to acquire basic monitoring and evaluation capabilities, be provided with opportunities for using these capabilities and be adequately motivated to care about evidence as a means to improve services to their clients. Leadership along with a phased in approach are key in bringing about these behaviour changes. Copyright © 2017. Published by Elsevier Ltd.

Experimental analysis in formation of anti-pp interactions between 0. and 1.2 GeV/c: evidence for a anti-pp→5π effect near 1950 MeV/c2

International Nuclear Information System (INIS)

Defoix, C.; Dobrzynski, L.; Espigat, P.; Laloum, M.; Ladron de Guevara, P.

1979-07-01

An experimental analysis of anti-pp interactions between the anti-pp threshold (√s=1878 MeV) and √s=2100 MeV leads to clear evidence for an s-channel effect in the reaction anti-pp→π + π - π + π - π 0 at 1949+-10 MeV/c 2 (GAMMA approximately 80 MeV/c 2 ). Comparison is made with the backward elastic scattering and charge-exchange behaviors. An interpretation in terms of an object strongly coupled to mesonic decay modes, with a sma-1 or middle-sized elasticity (x<=0.135 + 0.13 (or -0.06)) is given. No significant narrow structure is observed in the backward elastic scattering between 1.9 and 2 GeV. The experimental resolution on √s in this case is 2 MeV

Climate warming drives local extinction: Evidence from observation and experimentation

Science.gov (United States)

Panetta, Anne Marie; Stanton, Maureen L.; Harte, John

2018-01-01

Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant (Androsace septentrionalis). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues. PMID:29507884

The flaws and human harms of animal experimentation.

Science.gov (United States)

Akhtar, Aysha

2015-10-01

Nonhuman animal ("animal") experimentation is typically defended by arguments that it is reliable, that animals provide sufficiently good models of human biology and diseases to yield relevant information, and that, consequently, its use provides major human health benefits. I demonstrate that a growing body of scientific literature critically assessing the validity of animal experimentation generally (and animal modeling specifically) raises important concerns about its reliability and predictive value for human outcomes and for understanding human physiology. The unreliability of animal experimentation across a wide range of areas undermines scientific arguments in favor of the practice. Additionally, I show how animal experimentation often significantly harms humans through misleading safety studies, potential abandonment of effective therapeutics, and direction of resources away from more effective testing methods. The resulting evidence suggests that the collective harms and costs to humans from animal experimentation outweigh potential benefits and that resources would be better invested in developing human-based testing methods.

An experimenter's history of neutral currents

International Nuclear Information System (INIS)

Sciulli, F.

1979-01-01

The history of the experimental study of neutral currents, defined as the class of weak interactions engaged in by lepton pairs of net zero charge, is traced under the headings; historical motivations, experimental searches, first positive indications, neutral currents corroborated, neutrino experiments on neutral currents and some general experimental comments. It is concluded that the neutral current does exist and predicted on the basis of gauge theory ideas, and though to connect the weak and electromagnetic interactions, its very general experimental properties are quite consistent with those ideas. Among these are flavor conserving complicated isospin structure, complicated V, A structure and a structure which depends on the type (or quantum numbers) of the target. 50 references. (UK)

The use of albumin in the complications of cirrhosis: evidence and future perspectives

Directory of Open Access Journals (Sweden)

Alessandra Tovoli

2013-07-01

Full Text Available The therapeutic use of albumin in cirrhosis dates back to the 50s, when hypoalbuminemia was thought to play a crucial role in the pathophysiology of ascites. Today, while its efficacy in the treatment of ascites is still under investigation, it has been proved that albumin is able to improve patient outcome and survival in some specific complications of cirrhosis, such as the prevention of post-paracentesis circulatory dysfunction and the treatment of spontaneous bacterial peritonitis and hepatorenal syndrome. Beside its oncotic power, albumin carries other biological properties, the so called non-oncotic properties, including transportation and detoxification of several molecules, free radical scavenging, modulation of vascular permeability, activity on the immune system and on the haemostatic balance. Some experimental evidences indicate that not only albumin concentration but also its function is reduced in patients with cirrhosis. However, the clinical implications of such functional abnormalities is still unclear. We here present the available evidence on the use of albumin in cirrhosis and future perspectives.http://dx.doi.org/10.7175/rhc.v4i3.659

Early Detection of Junctional Adhesion Molecule-1 (JAM-1 in the Circulation after Experimental and Clinical Polytrauma

Directory of Open Access Journals (Sweden)

Stephanie Denk

2015-01-01

Full Text Available Severe tissue trauma-induced systemic inflammation is often accompanied by evident or occult blood-organ barrier dysfunctions, frequently leading to multiple organ dysfunction. However, it is unknown whether specific barrier molecules are shed into the circulation early after trauma as potential indicators of an initial barrier dysfunction. The release of the barrier molecule junctional adhesion molecule-1 (JAM-1 was investigated in plasma of C57BL/6 mice 2 h after experimental mono- and polytrauma as well as in polytrauma patients (ISS ≥ 18 during a 10-day period. Correlation analyses were performed to indicate a linkage between JAM-1 plasma concentrations and organ failure. JAM-1 was systemically detected after experimental trauma in mice with blunt chest trauma as a driving force. Accordingly, JAM-1 was reduced in lung tissue after pulmonary contusion and JAM-1 plasma levels significantly correlated with increased protein levels in the bronchoalveolar lavage as a sign for alveolocapillary barrier dysfunction. Furthermore, JAM-1 was markedly released into the plasma of polytrauma patients as early as 4 h after the trauma insult and significantly correlated with severity of disease and organ dysfunction (APACHE II and SOFA score. The data support an early injury- and time-dependent appearance of the barrier molecule JAM-1 in the circulation indicative of a commencing trauma-induced barrier dysfunction.

Early Detection of Junctional Adhesion Molecule-1 (JAM-1) in the Circulation after Experimental and Clinical Polytrauma

Science.gov (United States)

Denk, Stephanie; Wiegner, Rebecca; Hönes, Felix M.; Messerer, David A. C.; Radermacher, Peter; Kalbitz, Miriam; Braumüller, Sonja; McCook, Oscar; Gebhard, Florian; Weckbach, Sebastian; Huber-Lang, Markus

2015-01-01

Severe tissue trauma-induced systemic inflammation is often accompanied by evident or occult blood-organ barrier dysfunctions, frequently leading to multiple organ dysfunction. However, it is unknown whether specific barrier molecules are shed into the circulation early after trauma as potential indicators of an initial barrier dysfunction. The release of the barrier molecule junctional adhesion molecule-1 (JAM-1) was investigated in plasma of C57BL/6 mice 2 h after experimental mono- and polytrauma as well as in polytrauma patients (ISS ≥ 18) during a 10-day period. Correlation analyses were performed to indicate a linkage between JAM-1 plasma concentrations and organ failure. JAM-1 was systemically detected after experimental trauma in mice with blunt chest trauma as a driving force. Accordingly, JAM-1 was reduced in lung tissue after pulmonary contusion and JAM-1 plasma levels significantly correlated with increased protein levels in the bronchoalveolar lavage as a sign for alveolocapillary barrier dysfunction. Furthermore, JAM-1 was markedly released into the plasma of polytrauma patients as early as 4 h after the trauma insult and significantly correlated with severity of disease and organ dysfunction (APACHE II and SOFA score). The data support an early injury- and time-dependent appearance of the barrier molecule JAM-1 in the circulation indicative of a commencing trauma-induced barrier dysfunction. PMID:26556956

Point-counterpoint in physics: theoretical prediction and experimental discovery of elementary particles

International Nuclear Information System (INIS)

Lopes, J.L.

1984-01-01

A report is given on the theoretical prediction and the experimental discovery of elementary particles from the electron to the weak intermediate vector bosons. The work of Lattes, Occhialini and Powell which put in evidence the pions predicted by Yukawa was the starting point of the modern experimental particle physics. (Author) [pt

Sleep deprivation attenuates experimental stroke severity in rats

DEFF Research Database (Denmark)

Moldovan, Mihai; Constantinescu, Alexandra Oana; Balseanu, Adrian

2010-01-01

Indirect epidemiological and experimental evidence suggest that the severity of injury during stroke is influenced by prior sleep history. The aim of our study was to test the effect of acute sleep deprivation on early outcome following experimental stroke. Young male Sprague-Dawley rats (n=20...... after stroke was monitored using a battery of behavioral tests investigating the asymmetry of sensorimotor deficit (tape removal test and cylinder test), bilateral sensorimotor coordination (rotor-rod and Inclined plane) and memory (T-maze and radial maze). Following MCAO, control rats had impaired...

Indication for cataract surgery. Do we have evidence of who will benefit from surgery?

DEFF Research Database (Denmark)

Kessel, Line; Andresen, Jens; Erngaard, Ditte

2015-01-01

. To overcome this shortage of evidence, many systems have been developed internationally to prioritize patients on waiting lists for cataract surgery, but the Swedish NIKE (Nationell Indikationsmodell för Katarakt Ekstraktion) is the only system where an association to the preoperative scoring of a patient has...... been related to outcome of cataract surgery. We advise that clinicians are inspired by the NIKE system when they decide which patients to operate to ensure that surgery is only offered to patients who are expected to benefit from cataract surgery....

Experimental method for investigating helium effects in irradiated vanadium

International Nuclear Information System (INIS)

Smith, D.L.; Matsui, H.; Greenwood, L.; Loomis, B.

1987-10-01

Analyses have been performed which indicate that an effective method for experimentally investigating helium effects in neutron irradiated vanadium base alloys can be developed. The experimental procedure involves only modest modifications to existing procedures currently used for irradiation testing of vanadium-base alloys in the FFTF reactor. Helium is generated in the vanadium alloy by decay of tritium which is either preinjected or generated within the test capsule. Calculations indicate that nearly constant He/dpa ratios of desired magnitude can be attained by proper selection of experimental parameters. The proposed method could have a major impact on the development of vanadium base alloys for fusion reactor applications. 8 refs., 4 figs

Uranium mobility in non-oxidizing brines: field and experimental evidence

International Nuclear Information System (INIS)

Giblin, A.M.; Appleyard, E.C.

1987-01-01

The present distribution of U in the Wollaston Sediments in Saskatchewan can be related to the movement of brines as revealed in Na-Ca-Mg-Cl-metasomes. Experiments were conducted at 60 and 200 0 C under stringently non-oxidizing conditions using solvents ranging from distilled water to a Ca-Na-K brine formulated to simulate the major element composition of the Salton Sea geothermal brines. The experiments were conducted on natural pitchblende (UOsub(2.67)) and synthetic uraninite (UOsub(2.01)). Natural pitchblende was more strongly dissolved than the synthetic uraninite, and the synthetic Salton Sea brine was a more potent solvent than distilled water, 1:4 diluted Salton Sea brine, or pure NaCl brine. Within analytical limits of detection the dissolved U is present in the uranous (U 4+ ) state. The evidence demonstrates empirically the mechanism of dissolution of naturally occurring U minerals in reduced brines and describes a geological case where this appears to have happened. (author)

Indications of quantum diffusion of H in Pd

International Nuclear Information System (INIS)

Behar, M; Weiser, M.; Kalbitzer, S.

1989-01-01

Low temperature diffusion measurements of hydrogen in palladium using the nuclear reaction technique have shown indications of H quantum diffusion behaviour. For temperatures higher than 100 K the experimental diffusion coefficients follow an Arrhenius type behaviour. However, for lower temperatures (30 K 2 behaviour. (Author) [es

Queer challenges to evidence-based practice.

Science.gov (United States)

Zeeman, Laetitia; Aranda, Kay; Grant, Alec

2014-06-01

This paper aims to queer evidence-based practice by troubling the concepts of evidence, knowledge and mental illness. The evidence-based narrative that emerged within biomedicine has dominated health care. The biomedical notion of 'evidence' has been critiqued extensively and is seen as exclusive and limiting, and even though the social constructionist paradigm attempts to challenge the authority of biomedicine to legitimate what constitutes acceptable evidence or knowledge for those experiencing mental illness, biomedical notions of evidence appear to remain relatively intact. Queer theory offers theoretical tools to disrupt biomedical norms and challenges biomedical normativity to indicate how marginalisation occurs when normative truths about mental health classify those who differ from the norm as 'ill' or 'disordered'. Queer theory's emphasis on normativity serves the political aim to subvert marginalisation and bring about radical social and material change. Reference will be made to mental health subjects within each discourse by indicating how the body acts as a vehicle for knowing. Deleuzian notions of the rhizome are used as metaphor to suggest a relational approach to knowledge that does away with either/or positions in either biomedical, or queer knowledge to arrive at a both/and position where the biomedical, constructionist and queer are interrelated and entangled in needing the other for their own evolution. However, queer does not ask for assimilation but celebrates difference by remaining outside to disrupt that which is easily overlooked, assumed to be natural or represented as the norm. The task of queer knowledge is to do justice to the lives lived in the name of evidence-based practice and demands that we consider the relations of power where knowledge is produced. This pursuit creates different knowledge spaces where we identify new intersections that allow for socially just understandings of knowing or evidence to emerge. © 2013 John Wiley

Indication criteria for total hip or knee arthroplasty in osteoarthritis: a state-of-the-science overview.

Science.gov (United States)

Gademan, Maaike G J; Hofstede, Stefanie N; Vliet Vlieland, Thea P M; Nelissen, Rob G H H; Marang-van de Mheen, Perla J

2016-11-09

This systematic review gives an overview of guidelines and original publications as well as the evidence on which the currently proposed indication criteria are based. Until now such a state-of-the-science overview was lacking. Websites of orthopaedic and arthritis organizations (English/Dutch language) were independently searched by two authors for THA/TKA guidelines for OA. Furthermore, a systematic search strategy in several databases through August 2014 was performed. Quality of the guidelines was assessed with the AGREE II instrument, which consists of 6 domains (maximum summed score of 6 indicating high quality). Also, the level of evidence of all included studies was assessed. We found 6 guidelines and 18 papers, out of 3065 references. The quality of the guidelines summed across 6 domains ranged from 0.46 to 4.78. In total, 12 THA, 10 TKA and 2 THA/TKA indication sets were found. Four studies stated that no evidence-based indication criteria are available. Indication criteria concerning THA/TKA consisted of the following domains: pain (in respectively 11 and 10 sets), function (12 and 7 sets), radiological changes (10 and 9 sets), failed conservative therapy (8 and 4 sets) and other indications (6 and 7 sets). Specific cut-off values or ranges were often not stated and the level of evidence was low. The indication criteria for THA/TKA are based on limited evidence. Empirical research is needed, especially regarding domain specific cut-off values or ranges at which the best postoperative outcomes are achieved for patients, taking into account the limited lifespan of a prosthesis.

Non-baryonic dark matter: observational evidence and detection methods

International Nuclear Information System (INIS)

Bergstroem, Lars

2000-01-01

The evidence for the existence of dark matter in the universe is reviewed. A general picture emerges, where both baryonic and non-baryonic dark matter is needed to explain current observations. In particular, a wealth of observational information points to the existence of a non-baryonic component, contributing between around 20 and 40% of the critical mass density needed to make the universe geometrically flat on large scales. In addition, an even larger contribution from vacuum energy (or cosmological constant) is indicated by recent observations. To the theoretically favoured particle candidates for non-baryonic dark matter belong axions, supersymmetric particles, and of less importance, massive neutrinos. The theoretical foundation and experimental situation for each of these is reviewed. Direct and indirect methods for detection of supersymmetric dark matter are described in some detail. Present experiments are just reaching the required sensitivity to discover or rule out some of these candidates, and major improvements are planned over the coming years. (author)

Experimental evidence of EDGE turbulence driven by multiple mechanisms in ATF

International Nuclear Information System (INIS)

Hidalgo, C.

1993-01-01

The scaling properties of edge fluctuations have been investigated using Langmuir probes in the edge region of the Advance Toroidal Facility (ATF). Fluctuations in the ion saturation current (ls/ls) and transport inferred from the fluctuations increase with increasing density gradient, while keeping unchanged local electron temperature. The modification of the electron temperature in the range (10-50) eV, Keeping constant the density profile, does not have any significant influence on ls/ ls. In regions were Er/B =0, the poloidal phase velocity of the fluctuations is given by vph 2Te/LnB. More then one of any so far proposed mechanisms must be invoked to explain all the experimental observations. (Author) 14 refs

An Experimental Evaluation of Competing Age-Predictions of Future Time Perspective between Workplace and Retirement Domains.

Science.gov (United States)

Kerry, Matthew J; Embretson, Susan E

2017-01-01

Future time perspective (FTP) is defined as "perceptions of the future as being limited or open-ended" (Lang and Carstensen, 2002; p. 125). The construct figures prominently in both workplace and retirement domains, but the age-predictions are competing: Workplace research predicts decreasing FTP age-change, in contrast, retirement scholars predict increasing FTP age-change. For the first time, these competing predictions are pitted in an experimental manipulation of subjective life expectancy (SLE). A sample of N = 207 older adults (age 45-60) working full-time (>30-h/week) were randomly assigned to SLE questions framed as either 'Live-to' or 'Die-by' to evaluate competing predictions for FTP. Results indicate general support for decreasing age-change in FTP, indicated by independent-sample t -tests showing lower FTP in the 'Die-by' framing condition. Further general-linear model analyses were conducted to test for interaction effects of retirement planning with experimental framings on FTP and intended retirement; While retirement planning buffered FTP's decrease, simple-effects also revealed that retirement planning increased intentions for sooner retirement, but lack of planning increased intentions for later retirement. Discussion centers on practical implications of our findings and consequences validity evidence in future empirical research of FTP in both workplace and retirement domains.

Experimental Evaluation of Host Adaptation of Lactobacillus reuteri to Different Vertebrate Species.

Science.gov (United States)

Duar, Rebbeca M; Frese, Steven A; Lin, Xiaoxi B; Fernando, Samodha C; Burkey, Thomas E; Tasseva, Guergana; Peterson, Daniel A; Blom, Jochen; Wenzel, Cory Q; Szymanski, Christine M; Walter, Jens

2017-06-15

The species Lactobacillus reuteri has diversified into host-specific lineages, implying a long-term association with different vertebrates. Strains from rodent lineages show specific adaptations to mice, but the processes underlying the evolution of L. reuteri in other hosts remain unknown. We administered three standardized inocula composed of strains from different host-confined lineages to mice, pigs, chickens, and humans. The ecological performance of each strain in the gastrointestinal tract of each host was determined by typing random colonies recovered from fecal samples collected over five consecutive days postadministration. Results revealed that rodent strains were predominant in mice, confirming previous findings of host adaptation. In chickens, poultry strains of the lineage VI (poultry VI) and human isolates from the same lineage (human VI) were recovered at the highest and second highest rates, respectively. Interestingly, human VI strains were virtually undetected in human feces. These findings, together with ancestral state reconstructions, indicate poultry VI and human VI strains share an evolutionary history with chickens. Genomic analysis revealed that poultry VI strains possess a large and variable accessory genome, whereas human VI strains display low genetic diversity and possess genes encoding antibiotic resistance and capsular polysaccharide synthesis, which might have allowed temporal colonization of humans. Experiments in pigs and humans did not provide evidence of host adaptation of L. reuteri to these hosts. Overall, our findings demonstrate host adaptation of L. reuteri to rodents and chickens, supporting a joint evolution of this bacterial species with several vertebrate hosts, although questions remain about its natural history in humans and pigs. IMPORTANCE Gut microbes are often hypothesized to have coevolved with their vertebrate hosts. However, the evidence is sparse and the evolutionary mechanisms have not been identified. We

Pain and executive functions: A unique relationship between Stroop task and experimentally induced pain

NARCIS (Netherlands)

Bjekic, J.; Zivanovic, M.; Puric, D.; Oosterman, J.M.; Filipovic, S.R.

2018-01-01

There is a growing body of evidence that a higher level of cognitive inhibition is associated with lower experimental pain sensitivity. However, a systematic examination of the association between executive functions, which include not only inhibition but also updating and shifting, and experimental

Disclosure indices design: does it make a difference?

Directory of Open Access Journals (Sweden)

Francisco Bravo Urquiza

2009-07-01

Full Text Available Measurement of information disclosed by companies is a complex task. Accounting research usually relies on disclosure indices to obtain a proxy for the information disclosed by companies. However, there is no consensus about the best design for these indices. The purpose of this paper is to investigate if there are significant differences among the indices that are used in disclosure studies. Three indices that measure disclosure of forward-looking information are compared: A “quality index” of a multidimensional nature; a “scope index” designed specifically to measure the scope of information, and a “quantity index” that measures information disclosed exclusively in terms of quantity. Results of the empirical analysis indicate that although the indices are correlated, they have a big impact in the rankings of companies. Evidence against the idea of the irrelevance of the particular index chosen is provided.

Competition and quality indicators in the health care sector: empirical evidence from the Dutch hospital sector

NARCIS (Netherlands)

Croes, R.R.; Krabbe-Alkemade, Y.J.F.M.; Mikkers, M.C.

2017-01-01

textabstractThere is much debate about the effect of competition in healthcare and especially the effect of competition on the quality of healthcare, although empirical evidence on this subject is mixed. The Netherlands provides an interesting case in this debate. The Dutch system could be

Quasi-experimental study designs series-paper 8: identifying quasi-experimental studies to inform systematic reviews.

Science.gov (United States)

Glanville, Julie; Eyers, John; Jones, Andrew M; Shemilt, Ian; Wang, Grace; Johansen, Marit; Fiander, Michelle; Rothstein, Hannah

2017-09-01

This article reviews the available evidence and guidance on methods to identify reports of quasi-experimental (QE) studies to inform systematic reviews of health care, public health, international development, education, crime and justice, and social welfare. Research, guidance, and examples of search strategies were identified by searching a range of databases, key guidance documents, selected reviews, conference proceedings, and personal communication. Current practice and research evidence were summarized. Four thousand nine hundred twenty-four records were retrieved by database searches, and additional documents were obtained by other searches. QE studies are challenging to identify efficiently because they have no standardized nomenclature and may be indexed in various ways. Reliable search filters are not available. There is a lack of specific resources devoted to collecting QE studies and little evidence on where best to search. Searches to identify QE studies should search a range of resources and, until indexing improves, use strategies that focus on the topic rather than the study design. Better definitions, better indexing in databases, prospective registers, and reporting guidance are required to improve the retrieval of QE studies and promote systematic reviews of what works based on the evidence from such studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Understanding Counterfactuality: A Review of Experimental Evidence for the Dual Meaning of Counterfactuals

Science.gov (United States)

Nieuwland, Mante S.

2016-01-01

Abstract Cognitive and linguistic theories of counterfactual language comprehension assume that counterfactuals convey a dual meaning. Subjunctive‐counterfactual conditionals (e.g., ‘If Tom had studied hard, he would have passed the test’) express a supposition while implying the factual state of affairs (Tom has not studied hard and failed). The question of how counterfactual dual meaning plays out during language processing is currently gaining interest in psycholinguistics. Whereas numerous studies using offline measures of language processing consistently support counterfactual dual meaning, evidence coming from online studies is less conclusive. Here, we review the available studies that examine online counterfactual language comprehension through behavioural measurement (self‐paced reading times, eye‐tracking) and neuroimaging (electroencephalography, functional magnetic resonance imaging). While we argue that these studies do not offer direct evidence for the online computation of counterfactual dual meaning, they provide valuable information about the way counterfactual meaning unfolds in time and influences successive information processing. Further advances in research on counterfactual comprehension require more specific predictions about how counterfactual dual meaning impacts incremental sentence processing. PMID:27512408

Relationship among Translational Medicine, Evidence-Based Medicine and Precision Medicine

OpenAIRE

Xin-en HUANG

2016-01-01

Translational medicine is a new concept in international medical field. It integrates experimental research results and clinical guidance into the optimal implementation criteria for promoting the prediction, prevention and treatment of diseases. Based on people’s higher demand for medicine and health, appearance of translational medicine changes the mode of medical research.Evidence-based medicine (EBM) refers to cautious and accurate application of the current best research evidence and com...

Neuroprotection of Catalpol for Experimental Acute Focal Ischemic Stroke: Preclinical Evidence and Possible Mechanisms of Antioxidation, Anti-Inflammation, and Antiapoptosis

Directory of Open Access Journals (Sweden)

Xia-wei Zheng

2017-01-01

Full Text Available Neuroprotection is defined as using a therapy that affects the brain tissue in the still-viable ischemic penumbra to salvage or delay the infarction. Catalpol, the main active principle of the root of Radix Rehmanniae, was reported to have pleiotropic neuroprotective effects in neurodegenerative diseases including ischemic stroke. Here, we evaluated the neuroprotective effects of catalpol in experimental acute ischemic stroke. Studies on catalpol in animal models of acute ischemic stroke were identified from 6 databases. Twenty-five studies involving 805 animals were included. Twelve comparisons showed significant effects of catalpol on decreasing infarct size according to 2,3,5-triphenyltetrazolium chloride staining compared with the control (P<0.05. One study reported significant effect of catalpol on reducing infarct size according to magnetic resonance imaging scan compared with the control (P<0.05. Meta-analysis of these studies indicated that catalpol significantly improved the neurological function score according to Zea Longa score, Bederson score, balance beam-walking test, adhesive removal test, bar-grasping score, and corner test compared with the control (P<0.05. In conclusion, catalpol exerted neuroprotective effects for experimental acute focal ischemic stroke, largely through reducing oxidative reactions, inhibiting apoptosis, and repressing inflammatory reactions and autophagy. However, these apparently positive findings should be interpreted with caution because of the methodological flaws.

Sensitivity of stock market indices to oil prices: Evidence from manufacturing sub-sectors in Turkey

Directory of Open Access Journals (Sweden)

Eksi Halil Ibrahim

2012-01-01

Full Text Available Crude oil price is a critical cost factor for manufacturing industries that are of vital importance for economic growth. This study examines the relationship between crude oil prices and the indices of seven Turkish manufacturing sub-sectors over the period 1997:01-2009:12. The error correction model results reveal the long term causality from crude oil prices to chemical petroleum-plastic and basic metal sub-sectors indicating that these sub-sectors are highly sensitive to crude oil prices. We find no causal relationship for other sector indices for short or long time periods.

Design of energy management indicator.

Directory of Open Access Journals (Sweden)

Ernesto Tomás Dalmau García

2010-10-01

Full Text Available This work has as a main goal to demostrate the viability of the energy management indicator, that will be a part of the Balanced Scorecard in the organization and the own process of calculation allows to obtain a Balanced Scorecard of energy management. It describes the executive order of the actions that have to be done to reach to the mentioned indicator, based on the selection of the selected period of time; the types of power carriers, the weight of each carrier in the structure of the consumption and the activities where they are used. With these elements several tools are used to reach to the expected results, as the bar charts, comparative tables and indices of power intensity. The indices of energy intensity are recommended as comparative elements for the contribution to the operativity and information level, meaning that not always is necessary to tie them , if not, in some cases, may be other selected indicators that may result as qualitatives type, The Cuban enterprise system uses the model Control of Consumption and Catchment Demand of fuels and lubricants (CDA 002 of the Ministry of Economy and Planning (MEP that is used in the work and it is recommended for the organizations who apply it. The study and application of this method were made in the Company of Raw materials Recovery in an experimental form.

Biological indices of soil quality: an ecosystem case study of their use

Science.gov (United States)

Jennifer D. Knoepp; David C. Coleman; D.A. Crossley; James S. Clark

2000-01-01

Soil quality indices can help ensure that site productivity and soil function are maintained. Biological indices yield evidence of how a soil functions and interacts with the plants, animals, and climate that comprise an ecosystem. Soil scientists can identify and quantify both chemical and biological soil-quality indicators for ecosystems with a single main function,...

Competition and quality indicators in the health care sector : Empirical evidence from the Dutch hospital sector

NARCIS (Netherlands)

Croes, Ramsis; Krabbe, Yvonne; Mikkers, Misja

There is much debate about the effect of competition in healthcare and especially the effect of competition on the quality of healthcare, although empirical evidence on this subject is mixed. The Netherlands provides an interesting case in this debate. The Dutch system could be characterized as a

Experimental evidence for the reducibility of multifragment emission probabilities

International Nuclear Information System (INIS)

Wozniak, G.J.; Tso, K.; Phair, L.

1995-01-01

Multifragmentation has been studied for 36 Ar-induced reactions on a 197 Au target at E/A = 80 and 110 MeV and for 129 Xe-induced reactions on several targets ( nat Cu, 89 y, 165 ho, 197 Au) and E/A = 40, 50 and 60 MeV. The probability of emitting n intermediate-mass-fragments is shown to be binomial at each transversal energy and reducible to an elementary binary probability p. For each target and at each bombarding energy, this probability p shows a thermal nature by giving linear Arrhenius plots. For the 129 Xe-induced reactions, a nearly universal linear Arrhenius plot is observed at each bombarding energy, indicating a large degree of target independence

Experimental Evidence of Edge turbulence driven by multiple mechanisms in ATF

International Nuclear Information System (INIS)

Hidalgo, C.; Harris, J.M.; Uckran, T.; Manson, G.R.; Bell, J.D.

1993-01-01

The scaling properties of edge fluctuations have been investigated using Langmuir probes in the edge region of the Advance Toroidal Facility (ATF). Fluctuations in the ion saturation current (I s /I s ) and transport inferred from the fluctuations increase with increasing density gradient, while keeping unchanged local electron temperature. The modification of the electron temperature in the range (10-50) eV, Keeping constant the density profile, does not have any significant influence on I s /I s . In regions were E r /B∼0, the poloidal phase velocity of the fluctuations is given by V p h∼ 2T e L n B. More then one of any so far proposed mechanisms must be invoked to explain all the experimental observations.(Author)

Direct Experimental Evidence of Back-Surface Acceleration from Laser-Irradiated Foils

International Nuclear Information System (INIS)

Allen, M; Patel, P; Mackinnon, A; Price, D; Wilks, S; Morse, E

2004-01-01

Au foils were irradiated with a 100-TW, 100-fs laser at intensities greater than 10 20 W/cm 2 producing proton beams with a total yield of ∼ 10 11 and maximum proton energy of > 9 MeV. Removing contamination from the back surface of Au foils with an Ar-ion sputter gun reduced the total yield of accelerated protons to less than 1% of the yield observed without removing contamination. Removing contamination the front surface (laser-interaction side) of the target had no observable effect on the proton beam. We present a one-dimensional particle-in-cell simulation that models the experiment. Both experimental and simulation results are consistent with the back-surface acceleration mechanism described in the text

Work at night and breast cancer--report on evidence-based options for preventive actions

DEFF Research Database (Denmark)

Bonde, Jens Peter; Hansen, Johnni; Kolstad, Henrik Albert

2012-01-01

In 2007, the International Agency for Research on Cancer classified shift work involving circadian disruption as probably carcinogenic to humans (group 2A), primarily based on experimental and epidemiologic evidence for breast cancer. In order to examine options for evidence-based preventive acti...

THE POSITION OF INDIRECT EVIDENCE AS VERIFICATION TOOLS IN THE CARTEL CASE

Directory of Open Access Journals (Sweden)

Veri Antoni

2014-06-01

Full Text Available Indirect (circumstantial evidence, either economic evidence or communication evidence, has been used in cartel cases in many countries such as United States of America, Japan, Australia, Brazil, Malaysia, and others. According to Indonesia criminal procedure law, the position of indirect (circumstantial evidence is categorized as an indication (clue evidence whereas according to Indonesia civil procedure law, indirect (circumstantial evidence is categorized as presumption. Considering the characteristics the antimonopoly law which aims to find material truth, the position of indirect evidence is more properly said to be an indication. Owing to its status as an indication, indirect evidence should be exhibited together with the other direct evidence.   Indirect evidenceatau bukti tidak langsung, baik bukti ekonomi atau bukti komunikasi, telah digunakan dalam kasus-kasus kartel di banyak negara, seperti Amerika Serikat, Jepang, Australia, Brazil, Malaysia, dan lain-lain. Menurut hukum acara pidana Indonesia, posisi bukti tidak langsung dikategorikan sebagai indikasi (bukti petunjuk, padahal menurut hukum acara perdata Indonesia, bukti tidak langsung dikategorikan sebagai praduga. Mengingat karakteristik hukum anti-monopoli yang bertujuan untuk mencari kebenaran materiil, posisi bukti tidak langsung lebih tepat dikatakan indikasi. Karena statusnya sebagai indikasi, bukti tidak langsung harus dipamerkan bersama dengan bukti langsung lainnya.

Experimental evidence of nitrous acid formation in the electron beam treatment of flue gas

International Nuclear Information System (INIS)

Maetzing, H.; Namba, H.; Tokunaga, O.

1994-01-01

In the Electron Beam Dry Scrubbing (EBDS) process, flue gas from fossil fuel burning power plants is irradiated with accelerated (300-800 keV) electrons. Thereby, nitrogen oxide (NO x ) and sulfur dioxide (SO 2 ) traces are transformed into nitric and sulfuric acids, respectively, which are converted into particulate ammonium nitrate and sulfate upon the addition of ammonia. The powdery product can be filtered from the main gas stream and can be sold as agricultural fertilizer. A lot of experimental investigations have been performed on the EBDS process and computer models have been developed to interpret the experimental results and to predict economic improvements. According to the model calculations, substantial amounts of intermediate nitrous acid (HNO 2 ) are formed in the electron beam treatment of flue gas. The first experimental investigation about the formation of nitrous acid in an irradiated mixture of NO in synthetic air has been undertaken. Under these conditions, aerosol formation is avoided. UV spectra of the irradiated gas were recorded in the wavelength range λ = 345-375 nm. Both NO 2 and HNO 2 have characteristic absorption bands in this wavelength range. Calibration spectra of NO 2 were subtracted from the sample spectra. The remaining absorption bands can clearly be assigned to nitrous acid. The concentration of nitrous acid was determined by differential optical absorption. It was found lower than the model prediction. The importance of nitrous acid formation in the EBDS process needs to be clarified. (author)

Student Preferences and Performance in Online and Face-to-Face Classes Using Myers-Briggs Indicator: A Longitudinal Quasi-Experimental Study

Directory of Open Access Journals (Sweden)

Seta Boghikian-Whitby

2016-05-01

Full Text Available This longitudinal, quasi-experimental study investigated students’ cognitive personality type using the Myers-Briggs personality Type Indicator (MBTI in Internet-based Online and Face-to-Face (F2F modalities. A total of 1154 students enrolled in 28 Online and 32 F2F sections taught concurrently over a period of fourteen years. The study measured whether the sample is similar to the national average percentage frequency of all 16 different personality types; whether specific personality type students preferred a specific modality of instructions and if this preference changed over time; whether learning occurred in both class modalities; and whether specific personality type students learned more from a specific modality. Data was analyzed using regression, t-test, frequency, and Chi-Squared. The study concluded that data used in the study was similar to the national statistics; that no major differences in preference occurred over time; and that learning did occur in all modalities, with more statistically significant learning found in the Online modality versus F2F for Sensing, Thinking, and Perceiving types. Finally, Sensing and Thinking (ST and Sensing and Perceiving (SP group types learned significantly more in Online modality versus F2F.

Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

OpenAIRE

Xiao Wang; Wei Wang; Jingli Wang; Hao Wu; Chang Liu

2017-01-01

P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgG...

Orthodontic treatment with preadjusted appliances and low-friction ligatures: experimental evidence and clinical observations.

Science.gov (United States)

Baccetti, Tiziano; Franchi, Lorenzo; Fortini, Arturo

2008-01-01

To describe the features of low-friction ligatures during the leveling and aligning phase of fixed appliance therapy with preadjusted brackets. Experimental in vitro and in vivo studies were carried out to test the performance of the low-friction system with regard to leveling and aligning of the dental arches, as well as to increasing the transverse dimension of the maxillary arch. The outcomes of experimental testing showed that the combination of the low-friction ligatures with the superelastic nickel-titanium wires produced a significantly smaller amount of binding at the bracket/archwire/ligature unit when compared to conventional elastomeric ligatures. The biomechanical consequences of the use of low-friction ligatures were shorter duration of orthodontic treatment during the leveling and aligning phase, concurrent dentoalveolar expansion of the dental arch, and the possibility of using biologically adequate orthodontic forces.

An Investigation of Global Reporting Initiative Performance Indicators in Corporate Sustainability Reports: Greek, Italian and Spanish Evidence

Directory of Open Access Journals (Sweden)

Lara Tarquinio

2018-03-01

Full Text Available This study has two main purposes. First, it explores the performance indicators disclosed in the Global Reporting Initiative (GRI-based Sustainability Reports (SRs produced by the companies of three different countries: Italy, Spain and Greece. Second, it verifies how some corporate variables, country of origin variables and “attributes” of the SRs can explain the disclosure of GRI indicators. To verify the quantity and type of the indicators disclosed, we performed a content analysis of the SRs. We use a regression trees technique to describe how the companies’ variables explain a different use of the indicators. The findings show that Spanish companies, on average, disclose the greatest number of indicators. The social indicators related to Labour are those more frequently reported in the SRs of the three countries. The least reported are social indicators related to Human Rights. The results show the central role that assurance, ROA and sector may have in classifying the disclosure level of indicators. The study contributes both theoretical and empirical literature on sustainability indicators. It also sheds further light on the determinants of the disclosure of indicators.

Experimental analysis of multivariate female choice in gray treefrogs (Hyla versicolor): evidence for directional and stabilizing selection.

Science.gov (United States)

Gerhardt, H Carl; Brooks, Robert

2009-10-01

Even simple biological signals vary in several measurable dimensions. Understanding their evolution requires, therefore, a multivariate understanding of selection, including how different properties interact to determine the effectiveness of the signal. We combined experimental manipulation with multivariate selection analysis to assess female mate choice on the simple trilled calls of male gray treefrogs. We independently and randomly varied five behaviorally relevant acoustic properties in 154 synthetic calls. We compared response times of each of 154 females to one of these calls with its response to a standard call that had mean values of the five properties. We found directional and quadratic selection on two properties indicative of the amount of signaling, pulse number, and call rate. Canonical rotation of the fitness surface showed that these properties, along with pulse rate, contributed heavily to a major axis of stabilizing selection, a result consistent with univariate studies showing diminishing effects of increasing pulse number well beyond the mean. Spectral properties contributed to a second major axis of stabilizing selection. The single major axis of disruptive selection suggested that a combination of two temporal and two spectral properties with values differing from the mean should be especially attractive.

The impact of positive affect on health cognitions and behaviours: a meta-analysis of the experimental evidence.

Science.gov (United States)

Cameron, David S; Bertenshaw, Emma J; Sheeran, Paschal

2015-01-01

Several reviews suggest that positive affect is associated with improved longevity, fewer physical symptoms, and biological indicators of good health. It is possible that positive affect could influence these outcomes by promoting healthful cognitions and behaviours. The present review identified conceptual pathways from positive affect to health cognitions and behaviour, and used random effects meta-analysis to quantify the impact of positive affect inductions (versus neutral affect conditions) on these outcomes. Literature searches located 54 independent tests that could be included in the review. Across all studies, the findings revealed no reliable effects on intentions (d+ = -.12, 95% CI = -.32 to .08, k = 15) or behaviour (d+ = .15, 95% CI = -.03 to .33, k = 23). There were four reliable effects involving specific cognitions and behaviours, but little clear evidence for generalised benefits or adverse effects of positive emotions on health-related cognitions or actions. Conclusions must be cautious given the paucity of tests available for analysis. The review offers suggestions about research designs that might profitably be deployed in future studies, and calls for additional tests of the impact of discrete positive emotions on health cognitions and behaviour.

[Botulinum toxin type A in headache treatment : Established and experimental indications].

Science.gov (United States)

Gaul, C; Holle-Lee, D; Straube, A

2016-08-01

In recent years botulinum toxin type A has been used increasingly more in the treatment of specific headache disorders. Especially regarding chronic migraine with and without combined medication overuse, convincing randomized studies have proven the efficacy of this treatment option and have led to approval for this indication. Regarding other headache entities, such as episodic migraine, tension-type headache, trigeminal autonomic cephalalgia (TAC), neuralgic, neuropathic and myofascial pain, currently available scientific data on the efficacy of botulinum toxin type A are scarce and often ambiguous. The exact underlying mechanisms of the influence of botulinum toxin type A on the pathophysiology of headache are not completely clear but an influence on the release of calcitonin gene-related peptide (CGRP) seems to play a crucial role. This article summarizes the most important studies as well as experiences of treatment with botulinum toxin type A regarding different headache entities.

[Study on risk assessing indicator system after schistosomiasis transmission interruption in Wuxi City].

Science.gov (United States)

Xiao-Jun, Meng; Sheng-Hua, Zong; Xuan, Zhang; Dong-Lin, Gao; Yan-Hua, Qian; Bing, Lu

2017-07-27

To establish a risk assessing indicator system after the transmission interruption of schistosomiasis in Wuxi City, so as to provide evidences for formulating strategies on schistosomiasis control and prevention. A primary risk assessing indicator system was established based on the literature review. Alternative indicators were scored and screened to establish a final indicator system through two rounds of Delphy method and the related normalized weights and combined weights were also calculated. The risk assessing indicator system was established through two rounds of expert consultation including 3 first grade indicators and 15 second grade indicators. Among the first grade indicators, the normalized weights of natural environment, key populations and social environment were 0.370 6, 0.292 9 and 0.336 5, respectively. Among the second grade indicators, the migrant population accounted for the highest combined weight of 0.125 2 compared to domestic animal of 0.037 1. The authority degree among the first grade indicators was between 0.91 and 0.93, while the authority degree among the second grade indicators was between 0.79 and 0.92. The scientific and authoritative risk assessing indicator system after the transmission interruption of schistosomiasis is established, which provides the evidences for risk assessment on schistosomiasis transmission in Wuxi City.

Proposed system for measuring project performance using process-based key performance indicators

NARCIS (Netherlands)

Haponava, T.; Al-Jibouri, Saad H.S.

2012-01-01

Despite some evidence of its usefulness, performance measurement by using Key Performance Indicators (KPIs) in the construction industry also has its critics. Among the shortcomings attributed to existing KPIs is the fact that almost all of them are product oriented. This means that the indicators

Measurement and Enhancement of Plasticity Indices of some ...

African Journals Online (AJOL)

Experimental procedures were followed and one basic modification was made to Worrall and Khan measurement of rate of flow of plastic clays in order to prevent sud-den rush of compressed air. Results indicate that plasticity brought about by ageing can be measured for clays in aqueous and organic medium. Clays aged ...

Trichloroethylene: Mechanistic, epidemiologic and other supporting evidence of carcinogenic hazard.

Science.gov (United States)

Rusyn, Ivan; Chiu, Weihsueh A; Lash, Lawrence H; Kromhout, Hans; Hansen, Johnni; Guyton, Kathryn Z

2014-01-01

The chlorinated solvent trichloroethylene (TCE) is a ubiquitous environmental pollutant. The carcinogenic hazard of TCE was the subject of a 2012 evaluation by a Working Group of the International Agency for Research on Cancer (IARC). Information on exposures, relevant data from epidemiologic studies, bioassays in experimental animals, and toxicity and mechanism of action studies was used to conclude that TCE is carcinogenic to humans (Group 1). This article summarizes the key evidence forming the scientific bases for the IARC classification. Exposure to TCE from environmental sources (including hazardous waste sites and contaminated water) is common throughout the world. While workplace use of TCE has been declining, occupational exposures remain of concern, especially in developing countries. The strongest human evidence is from studies of occupational TCE exposure and kidney cancer. Positive, although less consistent, associations were reported for liver cancer and non-Hodgkin lymphoma. TCE is carcinogenic at multiple sites in multiple species and strains of experimental animals. The mechanistic evidence includes extensive data on the toxicokinetics and genotoxicity of TCE and its metabolites. Together, available evidence provided a cohesive database supporting the human cancer hazard of TCE, particularly in the kidney. For other target sites of carcinogenicity, mechanistic and other data were found to be more limited. Important sources of susceptibility to TCE toxicity and carcinogenicity were also reviewed by the Working Group. In all, consideration of the multiple evidence streams presented herein informed the IARC conclusions regarding the carcinogenicity of TCE. © 2013.

Nurse staffing and system integration and change indicators in acute care hospitals: evidence from a balanced scorecard.

Science.gov (United States)

McGillis Hall, Linda; Peterson, Jessica; Baker, G Ross; Brown, Adalsteinn D; Pink, George H; McKillop, Ian; Daniel, Imtiaz; Pedersen, Cheryl

2008-01-01

This study examined relationships between financial indicators for nurse staffing and organizational system integration and change indicators. These indicators, along with hospital location and type, were examined in relation to the nursing financial indicators. Results showed that different indicators predicted each of the outcome variables. Nursing care hours were predicted by the hospital type, geographic location, and the system. Both nursing and patient care hours were significantly related to dissemination and benchmarking of clinical data.

Evidence, temperature, and the laws of thermodynamics.

Science.gov (United States)

Vieland, Veronica J

2014-01-01

A primary purpose of statistical analysis in genetics is the measurement of the strength of evidence for or against hypotheses. As with any type of measurement, a properly calibrated measurement scale is necessary if we want to be able to meaningfully compare degrees of evidence across genetic data sets, across different types of genetic studies and/or across distinct experimental modalities. In previous papers in this journal and elsewhere, my colleagues and I have argued that geneticists ought to care about the scale on which statistical evidence is measured, and we have proposed the Kelvin temperature scale as a template for a context-independent measurement scale for statistical evidence. Moreover, we have claimed that, mathematically speaking, evidence and temperature may be one and the same thing. On first blush, this might seem absurd. Temperature is a property of systems following certain laws of nature (in particular, the 1st and 2nd Law of Thermodynamics) involving very physical quantities (e.g., energy) and processes (e.g., mechanical work). But what do the laws of thermodynamics have to do with statistical systems? Here I address that question. © 2014 S. Karger AG, Basel.

Proton NMR imaging in experimental ischemic infarction

International Nuclear Information System (INIS)

Buonanno, F.S.; Pykett, I.L.; Brady, T.J.; Vielma, J.; Burt, C.T.; Goldman, M.R.; Hinshaw, W.S.; Pohost, G.M.; Kistler, J.P.

1983-01-01

Proton nuclear magnetic resonance (NMR) images depict the distribution and concentration of mobile protons modified by the relaxation times T1 and T2. Using the steady-state-free-precession (SSFP) technique, serial coronal images were obtained sequentially over time in laboratory animals with experimental ischemic infarction. Image changes were evident as early as 2 hours after carotid artery ligation, and corresponded to areas of ischemic infarction noted pathologically. Resulting SSFP images in experimental stroke are contrasted to inversion-recovery NMR images in an illustrative patient with established cerebral infarction. Bulk T1 and T2 measurements were made in vitro in three groups of gerbils: normal, those with clinical evidence of infarction, and those clinically normal after carotid ligature. Infarcted hemispheres had significantly prolonged T1 and T2 (1.47 +/- .12 sec, 76.0 +/- 9.0 msec, respectively) when compared to the contralateral hemisphere (T1 . 1.28 +/- .05 sec, T2 . 58.7 +/- 3.9 msec) or to the other two groups. These data suggest that changes in NMR parameters occur and can be detected by NMR imaging as early as two hours after carotid artery ligation

Experimental evolution of sperm competitiveness in a mammal

Directory of Open Access Journals (Sweden)

Simmons Leigh W

2011-01-01

Full Text Available Abstract Background When females mate with multiple partners, sperm from rival males compete to fertilise the ova. Studies of experimental evolution have proven the selective action of sperm competition on male reproductive traits. However, while reproductive traits may evolve in response to sperm competition, this does not necessarily provide evidence that sperm competitive ability responds to selection. Indeed, a study of Drosophila failed to observe divergence in sperm competitive ability of males in lines selected for enhanced sperm offence and defence. Results Adopting the naturally polygamous house mouse (Mus domesticus as our vertebrate model, we performed an experimental evolution study and observed genetic divergence in sperm quality; males from the polygamous selection lines produced ejaculates with increased sperm numbers and greater sperm motility compared to males from the monogamous lines. Here, after 12 generations of experimental evolution, we conducted competitive matings between males from lineages evolving under sperm competition and males from lineages subject to relaxed selection. We reduced variation in paternity arising from embryo mortality by genotyping embryos in utero at 14 days gestation. Our microsatellite data revealed a significant paternity bias toward males that evolved under the selective regime of sperm competition. Conclusion We provide evidence that the sperm competitiveness phenotype can respond to selection, and show that improved sperm quality translates to greater competitive fertilisation success in house mice.

Experimental evidence for electron localization on Au upon photo-activation of Au/anatase catalysts

NARCIS (Netherlands)

Carneiro, J.T.; Carneiro, Joana T.; Savenije, Tom J.; Mul, Guido

2009-01-01

Time resolved microwave conductivity (TRMC) measurements show that the presence of Au on anatase Hombikat UV100 significantly reduces the lifetime of mobile electrons formed by photo-excitation of this photocatalyst at 300 nm, providing evidence for the widely acclaimed electron localization effect

Epistemologic inquiries in evidence-based medicine.

Science.gov (United States)

Djulbegovic, Benjamin; Guyatt, Gordon H; Ashcroft, Richard E

2009-04-01

enhance reasonableness or truthfulness of some particular claim ("evidence as a guide to truth"), and (3) to serve as a neutral arbiter among competing views. Our analysis indicates that EBM does not have a rigorous epistemological stance. In fact, EBM enthusiastically draws on all major traditions of philosophical theories of scientific evidence. Our findings indicate that EBM should not be construed as a new scientific or philosophical theory that changes the nature of medicine or our understanding thereof. Rather, we should consider EBM as a continuously evolving heuristic structure for optimizing clinical practice.

[Indication and Evidence of Internationally Developed Online Coaches as Intervention for Mental Illness - a Meta-Review].

Science.gov (United States)

Stein, Janine; Röhr, Susanne; Luck, Tobias; Löbner, Margrit; Riedel-Heller, Steffi G

2018-01-01

The aim of the study was to investigate the current state of research concerning internationally developed Online Coaches for treatment support and prevention of mental disorders. Evidence and effectiveness of the Online Coaches ought to be explored. A systematic literature search was performed in international databases in order to provide a meta-review of existing Online Coaches for mental disorders. The assessment of the methodological quality and evidence of the studies was based on the established guidelines of the Scottish Intercollegiate Guideline Network. 52 studies (24 meta-analyses, 16 systematic reviews, 2 health-technology assessment reports, and 10 RCT studies) were identified. The efficacy was demonstrated for a variety of Online Coaches for mental disorders, especially for anxiety and depressive disorders, insomnia, and post-traumatic stress disorders, with predominantly acceptable and high quality. The present work provides an overview of internationally developed Online Coaches in the field of mental health care. Online Coaches can serve as a useful supplement to the treatment and prevention of mental disorders. © Georg Thieme Verlag KG Stuttgart · New York.

BACTERIAL MORTALITY DUE TO SOLAR RADIATION, COMPARING EXPERIMENTAL AND STATISTICAL EVIDENCE

Science.gov (United States)

Many researchers report that sunlight is a primary stressor of beach indicator bacteria. Some water quality models include code that quantifies the effect of radiation on bacterial decay. For example, the EPA Visual Plumes model includes two coliform and one enterococcus submodel...

Community-wide job loss and teenage fertility: evidence from North Carolina.

Science.gov (United States)

Ananat, Elizabeth Oltmans; Gassman-Pines, Anna; Gibson-Davis, Christina

2013-12-01

Using North Carolina data for the period 1990-2010, we estimate the effects of economic downturns on the birthrates of 15- to 19-year-olds, using county-level business closings and layoffs as a plausibly exogenous source of variation in the strength of the local economy. We find little effect of job losses on the white teen birthrate. For black teens, however, job losses to 1 % of the working-age population decrease the birthrate by around 2 %. Birth declines start five months after the job loss and then last for more than one year. Linking the timing of job losses and conceptions suggests that black teen births decline because of increased terminations and perhaps also because of changes in prepregnancy behaviors. National data on risk behaviors also provide evidence that black teens reduce sexual activity and increase contraception use in response to job losses. Job losses seven to nine months after conception do not affect teen birthrates, indicating that teens do not anticipate job losses and lending confidence that job losses are "shocks" that can be viewed as quasi-experimental variation. We also find evidence that relatively advantaged black teens disproportionately abort after job losses, implying that the average child born to a black teen in the wake of job loss is relatively more disadvantaged.

Lichens as pollution indicators

Energy Technology Data Exchange (ETDEWEB)

Rose, F

1970-01-01

Although lichens are generally considered to be of little use to man, their sensitivity to air pollution makes them good biological indicators. The author describes how this feature can help to establish relative degrees of air pollution. He notes areas where lichens are reduced in number and vigor, and some in which they have disappeared altogether. He challenges the idea that dryness is responsible, since they have also disappeared from damp woodland areas. Experimental work supports the view that sulfur dioxide is the major factor rather than smoke, although there is no definitive proof. Lichen damage correlates best with mean winter levels of air pollution by SO/sub 2/. 16 references, 1 figure.

Visuospatial Orientational Shifts: Evidence for Three Independent Mechanisms.

Science.gov (United States)

Noonan, Michael; Axelrod, Seymour

While it is often assumed that a single mechanism underlies varied experimental evidences of selectivity, Berlyne (1969) suggested that attention-like selectivity may take place in a number of quite separate neural systems. This study examined the issue of visuospatial attention by investigating covert orientation or "looking out of the corner of…

Vanadium supersaturated silicon system: a theoretical and experimental approach

Science.gov (United States)

Garcia-Hemme, Eric; García, Gregorio; Palacios, Pablo; Montero, Daniel; García-Hernansanz, Rodrigo; Gonzalez-Diaz, Germán; Wahnon, Perla

2017-12-01

The effect of high dose vanadium ion implantation and pulsed laser annealing on the crystal structure and sub-bandgap optical absorption features of V-supersaturated silicon samples has been studied through the combination of experimental and theoretical approaches. Interest in V-supersaturated Si focusses on its potential as a material having a new band within the Si bandgap. Rutherford backscattering spectrometry measurements and formation energies computed through quantum calculations provide evidence that V atoms are mainly located at interstitial positions. The response of sub-bandgap spectral photoconductance is extended far into the infrared region of the spectrum. Theoretical simulations (based on density functional theory and many-body perturbation in GW approximation) bring to light that, in addition to V atoms at interstitial positions, Si defects should also be taken into account in explaining the experimental profile of the spectral photoconductance. The combination of experimental and theoretical methods provides evidence that the improved spectral photoconductance up to 6.2 µm (0.2 eV) is due to new sub-bandgap transitions, for which the new band due to V atoms within the Si bandgap plays an essential role. This enables the use of V-supersaturated silicon in the third generation of photovoltaic devices.

Basic Evidence and Properties of Single-Particle States in Nuclei

Energy Technology Data Exchange (ETDEWEB)

Cindro, N. [Institute ' ' Rudjer Boskovic' ' , Zagreb, Yugoslavia (Croatia)

1970-07-15

1. Introduction: the shell-model orbitals; 2. Information about single-particle orbitals: a critical evaluation; 3. Experimental evidence: 3.1. The lead region; 3.2. The calcium region; 3.3. Nuclei far from closed shells; 4. Conclusion. (author)

Vitamins Associated with Brain Aging, Mild Cognitive Impairment, and Alzheimer Disease: Biomarkers, Epidemiological and Experimental Evidence, Plausible Mechanisms, and Knowledge Gaps.

Science.gov (United States)

Fenech, Michael

2017-11-01

The key to preventing brain aging, mild cognitive impairment (MCI), and Alzheimer disease (AD) via vitamin intake is first to understand molecular mechanisms, then to deduce relevant biomarkers, and subsequently to test the level of evidence for the impact of vitamins in the relevant pathways and their modulation of dementia risk. This narrative review infers information on mechanisms from gene and metabolic defects associated with MCI and AD, and assesses the role of vitamins using recent results from animal and human studies. Current evidence suggests that all known vitamins and some "quasi-vitamins" are involved as cofactors or influence ≥1 of the 6 key sets of pathways or pathologies associated with MCI or AD, relating to 1 ) 1-carbon metabolism, 2 ) DNA damage and repair, 3 ) mitochondrial function and glucose metabolism, 4 ) lipid and phospholipid metabolism and myelination, 5 ) neurotransmitter synthesis and synaptogenesis, and 6 ) amyloidosis and Tau protein phosphorylation. The contemporary level of evidence for each of the vitamins varies considerably, but it is notable that B vitamins are involved as cofactors in all of the core pathways or pathologies and, together with vitamins C and E, are consistently associated with a protective role against dementia. Outcomes from recent studies indicate that the efficacy and safety of supplementation with vitamins to prevent MCI and the early stages of AD will most likely depend on 1 ) which pathways are defective, 2 ) which vitamins are deficient and could correct the relevant metabolic defects, and 3 ) the modulating impact of nutrient-nutrient and nutrient-genotype interaction. More focus on a precision nutrition approach is required to realize the full potential of vitamin therapy in preventing dementia and to avoid causing harm. © 2017 American Society for Nutrition.

Numerical evidence of chiral magnetic effect in lattice gauge theory

International Nuclear Information System (INIS)

Buividovich, P. V.; Chernodub, M. N.; Luschevskaya, E. V.; Polikarpov, M. I.

2009-01-01

The chiral magnetic effect is the generation of electric current of quarks along an external magnetic field in the background of topologically nontrivial gluon fields. There is recent evidence that this effect is observed by the STAR Collaboration in heavy-ion collisions at the Relativistic Heavy Ion Collider. In our paper we study qualitative signatures of the chiral magnetic effect using quenched lattice simulations. We find indications that the electric current is indeed enhanced in the direction of the magnetic field both in equilibrium configurations of the quantum gluon fields and in a smooth gluon background with nonzero topological charge. In the confinement phase the magnetic field enhances the local fluctuations of both the electric charge and chiral charge densities. In the deconfinement phase the effects of the magnetic field become smaller, possibly due to thermal screening. Using a simple model of a fireball we obtain a good agreement between our data and experimental results of STAR Collaboration.

Analysis on the science literacy ability of vocational school physics teacher using NOSLiT indicators

Science.gov (United States)

Rahayu, P. P.; Masykuri, M.; Soeparmi

2018-04-01

Professional Physics teacher must be able to manage science learning process by associating science itself with the daily life. At first the teacher must have competency in the ability of science literacy. The target of this research is vocational school Physics teachers for the purpose to describe their ability on science literacy. This research is a survey research using test method. The test instrument is The NOSLiT by Wenning.Research results are: 1) Scientific Nomenclature : 38.46 %, 2) Basic experimental and observational abilities : 38.46 %, 3) Rules of scientific evidence : 0%, 4) Postulate science: 15.38%, 5) scientific disposition: 7. 69%.Conclusion: The result of each indicator shows that the ability of science literacy of vocational school Physics teachers has not met the expectations yet. It’s can be used as the reflection for education experts to improve their science literacy ability so that can be applied to the learning process that directly or indirectly will have an impact on improving the students’ science literacy.

Development of an epiphyte indicator of nutrient enrichment. A ...

Science.gov (United States)

An extensive review of the literature on epiphytes on submerged aquatic vegetation (SAV), primarily seagrasses but including some brackish and freshwater rooted macrophytes, was conducted in order to evaluate the evidence for response of epiphyte metrics to increased nutrients. Evidence from field observational studies together with laboratory and field mesocosm experiments was assembled from the literature and evaluated for evidence of a hypothesized positive response to nutrient addition. There was general consistency in the results to confirm that elevated nutrients tended to increase the load of epiphytes on the surface of SAV, in the absence of other limiting factors. In spite of multiple sources of uncontrolled variation, positive relationships of epiphyte load to nutrient concentration or load (either N or P) were often observed along strong anthropogenic or natural nutrient gradients in coastal regions, although response patterns may only be evident for parts of the year. Mesocosm nutrient studies tended to be more common for temperate regions and field addition studies more common for tropical and subtropical regions. Addition of nutrients via the water column tended to elicit stronger epiphyte responses than sediment additions, and may be a factor in the lack of epiphyte response reported in some studies. Mesograzer activity is a critical covariate for epiphyte response under experimental nutrient elevation, but the epiphyte response is highly de

An Analytical Hierarchy Process Model for the Evaluation of College Experimental Teaching Quality

Science.gov (United States)

Yin, Qingli

2013-01-01

Taking into account the characteristics of college experimental teaching, through investigaton and analysis, evaluation indices and an Analytical Hierarchy Process (AHP) model of experimental teaching quality have been established following the analytical hierarchy process method, and the evaluation indices have been given reasonable weights. An…

Evaluation of linkages between equity indices : evidence from İstanbul Stock Exchange and Dow Jones

OpenAIRE

Ertan, Aytekin

2009-01-01

Ankara : The Department of Management, Bilkent Univiversity, 2009. Thesis (Master's) -- Bilkent University, 2009. Includes bibliographical references leaves 30-33. This study investigates the linkage between the major stock market indices of Turkey (ISE National 100) and USA (Dow Jones Industrial Average). Main purpose of this research is to measure the interdependence and cointegration between these indices and figure out the significance and the direction of short run r...

Inclusion of quasi-experimental studies in systematic reviews of health systems research.

Science.gov (United States)

Rockers, Peter C; Røttingen, John-Arne; Shemilt, Ian; Tugwell, Peter; Bärnighausen, Till

2015-04-01

Systematic reviews of health systems research commonly limit studies for evidence synthesis to randomized controlled trials. However, well-conducted quasi-experimental studies can provide strong evidence for causal inference. With this article, we aim to stimulate and inform discussions on including quasi-experiments in systematic reviews of health systems research. We define quasi-experimental studies as those that estimate causal effect sizes using exogenous variation in the exposure of interest that is not directly controlled by the researcher. We incorporate this definition into a non-hierarchical three-class taxonomy of study designs - experiments, quasi-experiments, and non-experiments. Based on a review of practice in three disciplines related to health systems research (epidemiology, economics, and political science), we discuss five commonly used study designs that fit our definition of quasi-experiments: natural experiments, instrumental variable analyses, regression discontinuity analyses, interrupted times series studies, and difference studies including controlled before-and-after designs, difference-in-difference designs and fixed effects analyses of panel data. We further review current practices regarding quasi-experimental studies in three non-health fields that utilize systematic reviews (education, development, and environment studies) to inform the design of approaches for synthesizing quasi-experimental evidence in health systems research. Ultimately, the aim of any review is practical: to provide useful information for policymakers, practitioners, and researchers. Future work should focus on building a consensus among users and producers of systematic reviews regarding the inclusion of quasi-experiments. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Using semantics for representing experimental protocols.

Science.gov (United States)

Giraldo, Olga; García, Alexander; López, Federico; Corcho, Oscar

2017-11-13

An experimental protocol is a sequence of tasks and operations executed to perform experimental research in biological and biomedical areas, e.g. biology, genetics, immunology, neurosciences, virology. Protocols often include references to equipment, reagents, descriptions of critical steps, troubleshooting and tips, as well as any other information that researchers deem important for facilitating the reusability of the protocol. Although experimental protocols are central to reproducibility, the descriptions are often cursory. There is the need for a unified framework with respect to the syntactic structure and the semantics for representing experimental protocols. In this paper we present "SMART Protocols ontology", an ontology for representing experimental protocols. Our ontology represents the protocol as a workflow with domain specific knowledge embedded within a document. We also present the S ample I nstrument R eagent O bjective (SIRO) model, which represents the minimal common information shared across experimental protocols. SIRO was conceived in the same realm as the Patient Intervention Comparison Outcome (PICO) model that supports search, retrieval and classification purposes in evidence based medicine. We evaluate our approach against a set of competency questions modeled as SPARQL queries and processed against a set of published and unpublished protocols modeled with the SP Ontology and the SIRO model. Our approach makes it possible to answer queries such as Which protocols use tumor tissue as a sample. Improving reporting structures for experimental protocols requires collective efforts from authors, peer reviewers, editors and funding bodies. The SP Ontology is a contribution towards this goal. We build upon previous experiences and bringing together the view of researchers managing protocols in their laboratory work. Website: https://smartprotocols.github.io/ .

A review of the evidence regarding associations between attachment theory and experimentally induced pain.

Science.gov (United States)

Meredith, Pamela Joy

2013-04-01

Theoretical and empirical evidence suggests that adult attachment and pain-related variables are predictably and consistently linked, and that understanding these links may guide pain intervention and prevention efforts. In general, insecure attachment has been portrayed as a risk factor, and secure attachment as a protective factor, for people with chronic pain conditions. In an effort to better understand the relationships among attachment and pain variables, these links have been investigated in pain-free samples using induced-pain techniques. The present paper reviews the available research linking adult attachment and laboratory-induced pain. While the diverse nature of the studies precludes definitive conclusions, together these papers offer support for associations between insecure attachment and a more negative pain experience. The evidence presented in this review highlights areas for further empirical attention, as well as providing some guidance for clinicians who may wish to employ preventive approaches and other interventions informed by attachment theory.

Is There a Purchase Limit on Regional Growth? A Quasi-experimental Evaluation of Investment Grants Using Matching Techniques

DEFF Research Database (Denmark)

Mitze, Timo Friedel; Paloyo, Alfredo R.; Alecke, Björn

2015-01-01

In this article, we apply recent advances in quasi-experimental estimation methods to analyze the effectiveness of Germany’s large-scale regional policy instrument, the joint Federal Government/State Programme “Gemeinschaftsaufgabe Verbesserung der regionalen Wirtschaftsstruktur” (GRW), which is ...... of matching techniques in regional data settings. Overall, however, the matching approach can still be considered of great value for regional policy analysis and should be the subject of future research efforts in the field of empirical regional science.......In this article, we apply recent advances in quasi-experimental estimation methods to analyze the effectiveness of Germany’s large-scale regional policy instrument, the joint Federal Government/State Programme “Gemeinschaftsaufgabe Verbesserung der regionalen Wirtschaftsstruktur” (GRW), which...... is a means to foster labor-productivity growth in lagging regions. In particular, adopting binary and generalized propensity-score matching methods, our results indicate that the GRW can be generally considered effective. However, we find evidence for a nonlinear relationship between GRW funding and regional...

Developing Sensitivity Indicators for Hydraulic Perturbation

Directory of Open Access Journals (Sweden)

M.M. Heidari

2016-02-01

Full Text Available Introduction: Determination the hydraulic performance of an irrigation network requires adequate knowledge about the sensitivities of the network structures. Hydraulic sensitivity concept of structures and channel reaches aid network operators in identifying structures with higher sensitivities which will attract more attention both during network operation and maintenance program. Sluice gates are frequently used as regulator and delivery structures in irrigation networks. Usually discharge coefficient of sluice gate is considered constant in the design and operation stage. Investigation of sensitivity of offtakes and cross-regulators has carried out by various researchers and some hydraulic sensitivity indicators have been developed. In the previous researches, these indexes were developed based on constant coefficient of discharge for free flow sluice gates. However, the coefficient of discharge for free flow sluice gates depend on gate opening and the upstream water depth. So, in this research, some hydraulic sensitivity indicators at structure based on variable coefficient of discharge for free flow sluice gates were developed and they were validated by using observed data. Materials and Methods: An experimental setup was constructed to analyses the performance of the some hydraulic sensitivity. The flume was provided with storage reservoir, pumps, electromagnetic flowmeter, entrance tank, feeder canal, delivery canals, offtakes, cross-regulators, collector reservoir, piezometric boards. The flume is 60.5 m long and the depth of that is 0.25 m, of which only a small part close to offtake and Cross-regulators was needed for these tests. Offtakes and Cross-regulators are free-flowing sluice gates type. Offtakes were located at distances 20 m and 42.5 m downstream from the entrance tank, respectively. and, Cross-regulators were located 2 m downstream from each offtakes. The offtakes are 0.21 m and Cross-regulators are 0.29 m wide. The upstream

Benefit of multiple trait selection to increase reproductive traits; experimental evidence from Golden hamsters.

NARCIS (Netherlands)

Satoh, M.; Nishida, A.; Arendonk, van J.A.M.; Lende, van der T.

1997-01-01

Fifteen generations of selection were conducted to study responses for litter size at birth (LSB), weight at weaning of standardized litter (LWW), and individual body weight at 8 wk of age (BW8) using golden hamsters as an experimental model for pigs. The experiment involved three lines: selection

Quark deconfinement in nuclei: A review of experimental tests based on nuclear magnetic moment measurements

International Nuclear Information System (INIS)

Stone, N.J.; Rikovska, J.

1988-01-01

The introduction very briefly outlines the basic idea and experimental evidence to suggest that quarks may behave differently in nuclei and in individual nucleons, with possible consequences for the calculation of nuclear magnetic dipole moments. After description of a calculation of moments made using the extreme model of total quark deconfinement (the MIT bag model) attention is focussed on experimental tests and the state of current evidence for more partial quark deconfinement. The arguments of Yamazaki which give an experimental basis for distinguishing quark deconfinement effects from, specifically, effects caused by pion exchange currents, are given in more detail. The reasons underlying choice of nuclei in which meaningful tests may be possible are given. Early claims by Karl et al. to have demonstrated the existence of quark deconfinement in mass 3 nuclei are discussed. The current status of evidence for deconfinement based on orbital g-factor measurements in heavier nuclei is also summarised. Finally some examples are given of possible experiments using recently developed on-line facilities which may provide further tests of these ideas. (orig.)

Evidence for robots.

Science.gov (United States)

Shenoy, Ravikiran; Nathwani, Dinesh

2017-01-01

Robots have been successfully used in commercial industry and have enabled humans to perform tasks which are repetitive, dangerous and requiring extreme force. Their role has evolved and now includes many aspects of surgery to improve safety and precision. Orthopaedic surgery is largely performed on bones which are rigid immobile structures which can easily be performed by robots with great precision. Robots have been designed for use in orthopaedic surgery including joint arthroplasty and spine surgery. Experimental studies have been published evaluating the role of robots in arthroscopy and trauma surgery. In this article, we will review the incorporation of robots in orthopaedic surgery looking into the evidence in their use. © The Authors, published by EDP Sciences, 2017.

Practical Biostatistics A Friendly Step-by-Step Approach for Evidence-based Medicine

CERN Document Server

Suchmacher, Mendel

2012-01-01

Evidence-based medicine aims to apply the best available evidence gained from the scientific method to medical decision making. It is a practice that uses statistical analysis of scientific methods and outcomes to drive further experimentation and diagnosis. The profusion of evidence-based medicine in medical practice and clinical research has produced a need for life scientists and clinical researchers to assimilate biostatistics into their work to meet efficacy and practical standards. Practical Biostatistics provides researchers, medical professionals, and students with a friendly, practica

[Creation of experimental emphysema by the intratracheal administration of papain].

Science.gov (United States)

Basmadzhieva, K; Kolev, K; Balabaeva, L

1981-01-01

The authors formed lung emphysema in white rats under experimental conditions by intratracheal application of various concentrations of papaine at different intervals. In the performed experiment the most suitable dose for formation of emphysema was two fold administration of 2 milligrams of papaine. The following indices were observed in the experimental and control animals: body weight, weight coefficient of the internal organs, indices of lipid and nucleinic metabolism in homogenates of lung as well as histomorphologic examination of lung.

Experimental and Theoretical Study of 1.5-Diamino-4-H-Tetrazolium Perchlorate

National Research Council Canada - National Science Library

Drake, Greg

2004-01-01

... out. Experimental evidence strongly supports the protonation of a nitrogen atom of the tetrazole ring, including the structure observed in a single crystal x-ray diffraction study of the title compound...

Indications for breast imaging in women under age 35

International Nuclear Information System (INIS)

Harris, V.J.; Jackson, V.P.

1988-01-01

Many women under age 35 years undergo breast imaging, and the vast majority of studies are normal or compatible with benign disease. In our series of 649 patients aged 13 - 34, the only significant indicators were a palpable mass or infection. In the 383 patients with either of these indications, mammographic and/or US findings were normal in 53%, compatible with benign disease in 14%, and suggestive of malignancy in 33%. Biopsy performed in 80 of these women revealed breast cancer in five (6%). None of the 266 women with low-yield indications (pain, modularity, galactorrhea, fibrocystic disease, screening) had significant imaging findings or clinical or surgical evidence of breast cancer

Genetic evidence for patrilocal mating behavior among Neandertal groups

DEFF Research Database (Denmark)

Lalueza-Fox, Carles; Rosas, Antonio; Estalrrich, Almudena

2011-01-01

The remains of 12 Neandertal individuals have been found at the El Sidrón site (Asturias, Spain), consisting of six adults, three adolescents, two juveniles, and one infant. Archaeological, paleontological, and geological evidence indicates that these individuals represent all or part of a contem...... of the three adult females carried different mtDNA lineages. These findings provide evidence to indicate that Neandertal groups not only were small and characterized by low genetic diversity but also were likely to have practiced patrilocal mating behavior....

Invasive physiological indices to determine the functional significance of coronary stenosis

Directory of Open Access Journals (Sweden)

Firas R. AL-Obaidi

2018-03-01

Full Text Available Physiological measurements are now commonly used to assess coronary lesions in the cardiac catheterisation laboratory, and this practice is evidence-based and supported by clinical guidelines. Fractional flow reserve is currently the gold standard method to determine whether coronary lesions are functionally significant, and is used to guide revascularization. There are however several other physiological measurements that have been proposed as alternatives to the fractional flow reserve. This review aims to comprehensively discuss physiological indices that can be used in the cardiac catheterisation laboratory to determine the functional significance of coronary lesions. We will focus on their advantages and disadvantages, and the current evidence supporting their use. Keywords: Coronary physiology, Fractional flow reserve, Resting physiological indices, Coronary flow reserve

At-risk children's use of reflection and revision in hands-on experimental activities

Science.gov (United States)

Petrosino, Anthony J., Jr.

The goal of this study was to investigate the effects of incorporating opportunities for reflection and revision in hands-on science instruction which emphasized experimentation using model rockets. The participants were low achieving sixth grade summer school students (n = 23) designated as at-risk for school failure by their district. The group was asked a series of interview questions based on work by Schauble et al. (1995) relating to experimentation. The interviews took place over three distinct time points corresponding to a "hands-on only" condition, a "hands-on with reflection and revision" condition and a "hands-on with repeated reflection and revision" condition. A Friedman's Two-Way Analysis of Variance by Ranks indicate students score low at first with traditional hands-on instruction but improve significantly with opportunities to reflect and revise their experiments. In addition, a sociocultural analysis was conducted during the summer school session to assess the model rocket activity as an apprenticeship, as guided participation and as participatory appropriation using a framework established by Rogoff (1994). Finally, a survey (the Classroom Environment Survey) was administered to the students measuring five constructs consistent with a constructivist classroom: participation, autonomy, relevance, commitment to learning and disruptions to learning. Analysis indicate students in the summer school model rocket intervention experienced a greater sense of constructivist principles during the activity than a similar comparison group utilizing reform minded instruction but not including opportunities for reflection and revision cycles. This research provides important evidence that, like scientists, students in school can learn effectively from extended practice in a varied context. Importantly, the data indicate that hands-on instruction is best utilized when opportunities for reflection and revision are made explicit. Implications are discussed related

Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods.

Directory of Open Access Journals (Sweden)

Allison E Nickel

Full Text Available While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test; for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test. Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness.

Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods

Science.gov (United States)

Nickel, Allison E.; Henke, Katharina; Hannula, Deborah E.

2015-01-01

While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test); for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test). Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness. PMID:26512726

Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods.

Science.gov (United States)

Nickel, Allison E; Henke, Katharina; Hannula, Deborah E

2015-01-01

While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test); for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test). Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness.

Theoretical approaches and experimental evidence for liquid-vapor phase transitions in nuclei

Energy Technology Data Exchange (ETDEWEB)

Moretto, L.G.; Elliott, J.B.; Phair, L.; Wozniak, G.J.; Mader, C.M.; Chappars, A.

2001-01-01

The leptodermous approximation is applied to nuclear systems for T > 0. The introduction of surface corrections leads to anomalous caloric curves and to negative heat capacities in the liquid-gas coexistence region. Clusterization in the vapor is described by associating surface energy to clusters according to Fisher's formula. The three-dimensional Ising model, a leptodermous system par excellence, does obey rigorously Fisher's scaling up to the critical point. Multifragmentation data from several experiments including the ISiS and EOS Collaborations, as well as compound nucleus fragment emission at much lower energy follow the same scaling, thus providing the strongest evidence yet of liquid-vapor coexistence.

The rights of man and animal experimentation.

OpenAIRE

Martin, J

1990-01-01

Since emotions give contradictory signals about animal experimentation in medical science, man's relationship to animals must be based upon reason. Thomas Aquinas argues that man is essentially different from animals because man's intellectual processes show evidence of an abstract mechanism not possessed by animals. Man's rights arise in association with this essential difference. The consequence is that only man possesses true rights by Aquinas's definition; animals have them only by analog...

Black swan protection: an experimental investigation

OpenAIRE

Morone, Andrea; Ozdemir, Ozlem

2012-01-01

This experimental study investigates insurance decisions in low-probability, high-loss risk situations. Results indicate that subjects consider the probability of loss (loss size) when they make buying decisions (paying decisions). Most individuals are risk averse with no specific threshold probability.

[Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique].

Science.gov (United States)

Jiang, Zhi-quan; Hu, Ke-liang

2016-03-01

In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science.

Experimental evidence for a Mott-Wigner glass phase of magnetite above the Verwey temperature

NARCIS (Netherlands)

Boekema, C.; Lichti, R.L.; Chan, K.C.B.; Brabers, V.A.M.; Denison, A.B.; Cooke, D.W.; Heffner, R.H.; Hutson, R.L.; Schillaci, M.E.

1986-01-01

New muon-spin-relaxation (µSR) results on magnetite are reported and discussed in light of earlier Mössbauer, neutron, and µSR results. Modification of the µSR anomaly (observed at 247 K in zero field), when an external magnetic field is applied, provides evidence that the anomaly results from cross

Multiple Lines of Evidence

Energy Technology Data Exchange (ETDEWEB)

Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Venzin, Alexander M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bramer, Lisa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-06-03

This paper discusses the process of identifying factors that influence the contamination level of a given decision area and then determining the likelihood that the area remains unacceptable. This process is referred to as lines of evidence. These lines of evidence then serve as inputs for the stratified compliance sampling (SCS) method, which requires a decision area to be divided into strata based upon contamination expectations. This is done in order to focus sampling efforts more within stratum where contamination is more likely and to use the domain knowledge about these likelihoods of the stratum remaining unacceptable to buy down the number of samples necessary, if possible. Two different building scenarios were considered as an example (see Table 3.1). SME expertise was elicited concerning four lines of evidence factors (see Table 3.2): 1) amount of contamination that was seen before decontamination, 2) post-decontamination air sampling information, 3) the applied decontaminant information, and 4) the surface material. Statistical experimental design and logistic regression modelling were used to help determine the likelihood that example stratum remained unacceptable for a given example scenario. The number of samples necessary for clearance was calculated by applying the SCS method to the example scenario, using the estimated likelihood of each stratum remaining unacceptable as was determined using the lines of evidence approach. The commonly used simple random sampling (SRS) method was also used to calculate the number of samples necessary for clearance for comparison purposes. The lines of evidence with SCS approach resulted in a 19% to 43% reduction in total number of samples necessary for clearance (see Table 3.6). The reduction depended upon the building scenario, as well as the level of percent clean criteria. A sensitivity analysis was also performed showing how changing the estimated likelihoods of stratum remaining unacceptable affect the number

Experimental survey of the potential energy surfaces associated with fission

International Nuclear Information System (INIS)

Britt, H.C.

1980-01-01

Progress in the experimental determination of the properties of the potential energy surface associated with fission is reviewed. The importance of nuclear symmetry effects on the calculation of fission widths is demonstrated. Evidence is presented for the fragmentation of the mass-asymmetric second barrier in the thorium region and the axial asymmetric first barrier in the californium region. Detailed analyses of experimental data suggest the presence of two parallel second barriers; the normal mass-asymmetric, axial-symmetric barrier and a slightly higher mass-symmetric, axial-asymmetric barrier. Experimental barrier parameters are determined systematically and compared with calculations from various theoretical models. Techniques for expanding fission probability measurements to higher energies are discussed. (author)

Experimental estimation of mutation rates in a wheat population with a gene genealogy approach.

Science.gov (United States)

Raquin, Anne-Laure; Depaulis, Frantz; Lambert, Amaury; Galic, Nathalie; Brabant, Philippe; Goldringer, Isabelle

2008-08-01

Microsatellite markers are extensively used to evaluate genetic diversity in natural or experimental evolving populations. Their high degree of polymorphism reflects their high mutation rates. Estimates of the mutation rates are therefore necessary when characterizing diversity in populations. As a complement to the classical experimental designs, we propose to use experimental populations, where the initial state is entirely known and some intermediate states have been thoroughly surveyed, thus providing a short timescale estimation together with a large number of cumulated meioses. In this article, we derived four original gene genealogy-based methods to assess mutation rates with limited bias due to relevant model assumptions incorporating the initial state, the number of new alleles, and the genetic effective population size. We studied the evolution of genetic diversity at 21 microsatellite markers, after 15 generations in an experimental wheat population. Compared to the parents, 23 new alleles were found in generation 15 at 9 of the 21 loci studied. We provide evidence that they arose by mutation. Corresponding estimates of the mutation rates ranged from 0 to 4.97 x 10(-3) per generation (i.e., year). Sequences of several alleles revealed that length polymorphism was only due to variation in the core of the microsatellite. Among different microsatellite characteristics, both the motif repeat number and an independent estimation of the Nei diversity were correlated with the novel diversity. Despite a reduced genetic effective size, global diversity at microsatellite markers increased in this population, suggesting that microsatellite diversity should be used with caution as an indicator in biodiversity conservation issues.

Innovation indicators: Towards a User’s guide

Energy Technology Data Exchange (ETDEWEB)

Iizuka, M.; Hollanders, H.

2016-07-01

The increased use of innovation indicators is observed in policy sphere. Several reasons are attributed for this increased use: first, access to data on innovation increased as the result of over half a century of efforts made by international organizations and researchers in this field; second, an increase in types and number of innovation indicators; third, its increased use in business contexts with the understanding that innovation is an integral part of business performance, which further spurred the use and development of innovation indicators (Soete and Freeman, 2009); fourth, the expansion in geographical coverage of countries, particularly in emerging countries of Latin America, Asia and Africa (Gault, 2010) making innovation indicators more policy (politics) relevant in a wider variety of countries, e.g. by allowing to benchmark and compare countries’ innovation performance; and fifth, the innovation indicators (in particular, the composite indicator but any indicator if used in ranking countries) became a communicative tool in public debate, in the backdrop of recent emphasis on ‘evidence based policy’ and ‘participatory decision making’ in the policy domain (OECD, 2012). Considering innovation indicators are intended to improve the performance of innovation policy, their increasing use is generally good news. Nevertheless, due to the increase in diversity in type and context in which indicators are being applied there is an increased occurrence of inappropriate use and misinterpretation of innovation indicators in the policy sphere. This paper first describes the specific cases then tries to generalize the problem aiming to build a general guideline or check list on the appropriate use of innovation indicators. (Author)

Experimental evidence for the influence of cognitions on compulsive buying.

Science.gov (United States)

McQueen, Paul; Moulding, Richard; Kyrios, Michael

2014-12-01

Compulsive buying is a disabling condition, where individuals are unable to resist or control their buying behavior, leading to substantial social and financial problems. Cognitive models implicate the role of beliefs as one factor in buying behavior, for example, "this item is unique and will help me improve my life". This study experimentally examined the contribution of such beliefs to the disorder, in individuals who compulsively buy (N = 18) and in non-clinical controls (N = 17). Participants were presented with photographs of idiosyncratically appealing and unappealing items, in the context of imagined scenarios that either minimized or maximized aspects relevant to hypothesized "compulsive buying beliefs" (i.e., beliefs that acquisition can compensate for negative feelings, beliefs regarding uniqueness and lost opportunities, and emotional reasons for buying). It was found that individuals who compulsively buy demonstrated stronger urges to purchase than control participants, regardless of context, but the overall strength of these urges was responsive to manipulations of beliefs about consumer items said to be associated with compulsive buying. The main limitation of the study was a small sample size, potentially reducing power. Nonetheless, these findings provide insights into the processes underlying compulsive phenomena, in particular supporting the role of cognitions in compulsive buying. Copyright © 2014 Elsevier Ltd. All rights reserved.

New Indicated Mean Effective Pressure (IMEP) model for predicting crankshaft movement

International Nuclear Information System (INIS)

Omran, Rabih; Younes, Rafic; Champoussin, Jean-Claude; Outbib, Rachid

2011-01-01

Highlights: → IMEP is essential to estimate the indicated torque in internal combustion engine. → We proposed model which describes the IMEP-Low pressure and the IMEP-High pressure. → We studied the evolution of the IMEP with respect to the engine's variables. → We deduced the variables of influence that can be used to develop the models. → The IMEP model is compared to transient experimental New European Driving Cycle. - Abstract: Indicated Mean Effective Pressure models (IMEP) are essential to estimate the indicated torque in internal combustion engine; they also provide important information about the mechanical efficiency of the engine thermodynamic cycle which describes the conversion of the fuel combustion energy into mechanical work. In the past, many researches were made to improve the IMEP prediction and measurement techniques at different engine operating conditions. In this paper, we proposed a detailed IMEP model which separately describes the IMEP-Low pressure and the IMEP-High pressure of a modern diesel engine; the IMEP is the direct subtraction result between these two variables. We firstly studied the evolution of the IMEP HP and IMEP LP with respect to the engine's variables and then we deduced the variables of influence and the form of the equations that can be used to develop the models. Finally, the models' coefficients were determined based on experimental data collected on a steady state test bench and using the least square regression method. In addition, the IMEP HP model results were compared to transient experimental data collected on a chassis dynamometer test bench; the model results are in excellent agreement with the experimental data.