bluuebunny/crossref_metadata_2025_split huggingface dataset:
Host adaptations reduce the reproductive success ofVarroa destructorin two distinct European honey bee populations
Authors: Locke Barbara , Conte Yves Le , Crauser Didier , Fries Ingemar 
Published: May 2012

AbstractHoney bee societies (Apis mellifera), the ectoparasitic miteVarroa destructor, and honey bee viruses that are vectored by the mite, form a complex system of host–parasite interactions. Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process. An increasing mite population means increasing transmission opportunities for viruses that can quickly develop into severe infections, killing a bee colony. Remarkably, a few subpopulations in Europe have survived mite infestation for extended periods of over 10 years without management by beekeepers and offer the possibility to study their natural host–parasite coevolution. Our study shows that two of these “natural” honey bee populations, in Avignon, France and Gotland, Sweden, have in fact evolved resistant traits that reduce the fitness of the mite (measured as the reproductive success), thereby reducing the parasitic load within the colony to evade the development of overt viral infections. Mite reproductive success was reduced by about 30% in both populations. Detailed examinations of mite reproductive parameters suggest these geographically and genetically distinct populations favor different mechanisms of resistance, even though they have experienced similar selection pressures of mite infestation. Compared to unrelated control colonies in the same location, mites in the Avignon population had high levels of infertility while in Gotland there was a higher proportions of mites that delayed initiation of egg‐laying. Possible explanations for the observed rapid coevolution are discussed.
A novel tracking jitter computation method for delay‐locked loops in spread‐spectrum systems
Authors: Groh Ingmar , Gentner Christian , Selva Jesus 
Published: May 2012

ABSTRACTIn spread‐spectrum navigation systems, the positioning error (or tracking accuracy) is determined from the jitter deviation of delay‐locked loops (DLLs). However, jitter simulations are computationally complex, and conventional analytical methods provide only unsatisfactory and incomplete jitter results. Thus, our contribution presents a novel method for the analytical jitter computation by mapping the stochastic differential equation (SDE) of the DLL onto an Ornstein–Uhlenbeck (OU) SDE. Its solution is the well‐known OU random process, which is a time‐variant Gaussian distribution. The expectation value and the variance of the OU random process yield the jitter deviation. Thus, we derive the analytical time‐variant jitter function with its transient response, which was to date unavailable. Contrary to previous jitter computations based on a loop transfer function, our method covers DLLs of any order. We obtain the loop parameters that minimise the jitter deviation analytically without computationally complex simulations. Above all, our method based on OU random processes enables for the first time an efficient joint analytical mean time to lose lock (MTLL) and jitter computation. Therefore, both computationally complex MTLL and jitter simulations become obsolete for many kinds of DLLs.Copyright © 2012 John Wiley & Sons, Ltd.
Cost‐effectiveness analysis of alternative treatments of African gambiense trypanosomiasis in Uganda
Authors: Politi Claudio , Carrin Guy , Evans David , Kuzoe F.A.S. , Cattand P.D. 
Published: May 2012

AbstractAfrican trypanosomiasis, or sleeping sickness, is a tropical disease caused by trypanosome parasites transmitted by tsetse flies. The focus of this paper is on the cost‐effectiveness of alternative drug treatments for patients in the late stage of the disease. Melarsoprol has been used for many decades. More recently, eflornithine has been developed. It has fewer side effects and improves the overall cure rate. It is much more expensive than melarsoprol, however.The objective of the present cost‐effectiveness is to identify the costs and benefits that would be involved in switching from melarsoprol to eflornithine in the treatment of late stage sleeping sickness. Benefits are expressed in lives saved as well as in disability adjusted life years (DALYs). The analysis is applied to the case of Uganda. The implications for affordability are also considered, by taking account of how the treatment costs would be shared between the national government, donors and patients.The baseline results indicate that melarsoprol treatment is associated with an incremental cost per life and DALY saved of $209 and $8, respectively. Each additional life saved by switching from melarsoprol alone to a combination of melarsoprol and eflornithine would cost an extra $1,033 per life saved, and an extra $40.9 per DALY gained. Shifting from this second alternative to treatment of all patients with eflornithine leads to an incremental cost per life saved of $4,444 and an incremental cost of $166.8 per DALY gained.
Confidence intervals for cost/effectiveness ratios
Authors: Wakker Peter , Klaassen Marc P. 
Published: May 2012

AbstractThe reduction of costs is becoming increasingly important in the medical field. The relevant topic of many clinical trials is not effectivenessper se, but rather cost‐effectiveness ratios. Surprisingly, no statistical tools for analyzing cost‐effectiveness ratios have been provided in the medical literature yet. This paper explains the gap in the literature, and provides a first technique for obtaining confidence intervals for cost‐effectiveness ratios. The technique does not use sophisticated tools to achieve maximal optimality, but seeks for tractability and ease of application while still satisfying all formal statistical requirements.
Where are we now in British health economics?
Authors: Blaug Mark 
Published: May 2012

AbstractHealth economics took off in 1970 or thereabouts, just after the take‐off date for the economics of education. Although early health economics made use of human capital theory as did the economics of education, it soon took a different route inspired by Arrow's work on medical insurance. The economics of education failed to live up to its promising start in the 1960s and gradually ran out of steam. The economics of health, however, has made steady theoretical and empirical progress since 1970, principally in coming to grips with the implications of supplier‐induced demand and the difficulties of evaluating health care outcomes. Some of the best work on British health economics has been in the area of normative welfare economics, defining more precisely what is meant by equity in the delivery of health care and measuring the degree of success in achieving equity. Recent efforts to reform the NHS by the introduction of ‘quasi markets’ have improved the quantity and quality of health care in Britain. In short, British health economics has been characterised by the use of Pigovian piecemeal rather than Paretian global welfare economics, retaining a distinctive style that sets it apart from American health economics.
Do Clinicians Conceptualize DSM‐IV Disorders Hierarchically?
Authors: Flanagan Elizabeth , Keeley Jared , Blashfield Roger 
Published: May 2012

ObjectiveAll classification systems of psychopathology use hierarchical categories. The purpose of the two studies in this article was to test whether clinicians think hierarchically about mental disorders.MethodSeventy six clinicians were asked to sort 67 diagnostic categories into groups using different instruction sets, either to make progressively larger and smaller groups of diagnoses (Study 1) or to place similar groups next to each other (Study 1 and Study 2).ResultsClinicians’ sortings of mental disorders had a hierarchical structure regardless of the methodology, profession, expertise, and instructional set used.ConclusionsGiven that all modern diagnostic systems have been hierarchical, it is important to know that clinicians' thinking is also hierarchical.
Stress and matrix‐responsive cytoskeletal remodeling in fibroblasts
Authors: Abbott Rosalyn D , Koptiuch Cathryn , Iatridis James C , Howe Alan K , Badger Gary J , Langevin Helene M 
Published: May 2012

AbstractIn areolar “loose” connective tissue, fibroblasts remodel their cytoskeleton within minutes in response to static stretch resulting in increased cell body cross‐sectional area that relaxes the tissue to a lower state of resting tension. It remains unknown whether the loosely arranged collagen matrix, characteristic of areolar connective tissue, is required for this cytoskeletal response to occur. The purpose of this study was to evaluate cytoskeletal remodeling of fibroblasts in, and dissociated from, areolar and dense connective tissue in response to 2 h of static stretch in both native tissue and collagen gels of varying crosslinking. Rheometric testing indicated that the areolar connective tissue had a lower dynamic modulus and was more viscous than the dense connective tissue. In response to stretch, cells within the more compliant areolar connective tissue adopted a large “sheet‐like” morphology that was in contrast to the smaller dendritic morphology in the dense connective tissue. By adjusting the in vitro collagen crosslinking, and the resulting dynamic modulus, it was demonstrated that cells dissociated from dense connective tissue are capable of responding when seeded into a compliant matrix, while cells dissociated from areolar connective tissue can lose their ability to respond when their matrix becomes stiffer. This set of experiments indicated stretch‐induced fibroblast expansion was dependent on the distinct matrix material properties of areolar connective tissues as opposed to the cells' tissue of origin. These results also suggest that disease and pathological processes with increased crosslinks, such as diabetes and fibrosis, could impair fibroblast responsiveness in connective tissues. J. Cell. Physiol. 228: 50–57, 2013. © 2012 Wiley Periodicals, Inc.
Methane treatment in biotrickling filters packed with inert materials in presence of a non‐ionic surfactant
Authors: Avalos Ramirez Antonio , Jones J. Peter , Heitz Michèle 
Published: May 2012

AbstractBACKGROUND: The treatment of methane in bioreactors with an aqueous phase such as biofilters is limited by low methane water solubility. In the case of biotrickling filters (BTF), the continuous trickling water is a barrier to methane transfer. In a previous study, the use of non‐ionic surfactants improved the performance of biofilters treating methane.RESULTS: Three BTFs treating methane were operated for 1 year under fixed operating conditions of methane concentration of 4.8 g m−3 and air flow rate of 0.25 m−3 h−1. Three kinds of packing material were tested and a non‐ionic surfactant (Brij 35) was periodically added to the nutrient solution at a concentration of 0.5% w/w. Methane conversion was a function of the type of packing materials and the presence of Brij 35 in the nutrient solution. When Brij 35 was added, the methane conversion doubled with respect to the BTFs without surfactant.CONCLUSION: The addition of Brij 35 to the nutrient solution increased the performance of the BTF for the three packing materials tested. The non‐ionic surfactant also affected the carbon dioxide production. The BTFs were stable when the packed bed was washed to remove the excess of biomass. Copyright © 2012 Society of Chemical Industry
Finding the neck–trunk boundary in snakes: Anteroposterior dissociation of myological characteristics in snakes and its implications for their neck and trunk body regionalization
Authors: Tsuihiji Takanobu , Kearney Maureen , Rieppel Olivier 
Published: May 2012

AbstractThe neck and trunk regionalization of the presacral musculoskeletal system in snakes and other limb‐reduced squamates was assessed based on observations on craniovertebral and body wall muscles. It was confirmed that myological features characterizing the neck in quadrupedal squamates (i.e., squamates with well‐developed limbs) are retained in all examined snakes, contradicting the complete lack of the neck in snakes hypothesized in previous studies. However, the posterior‐most origins of the craniovertebral muscles and the anterior‐most bony attachments of the body wall muscles that are located at around the neck–trunk boundary in quadrupedal squamates were found to be dissociated anteroposteriorly in snakes. Together with results of a recent study that the anterior expression boundaries of Hox genes coinciding with the neck–trunk boundary in quadrupedal amniotes were dissociated anteroposteriorly in a colubrid snake, these observations support the hypothesis that structures usually associated with the neck–trunk boundary in quadrupedal squamates are displaced relative to one another in snakes. Whereas certain craniovertebral muscles are elongated in some snakes, results of optimization on an ophidian cladogram show that the most recent common ancestor of extant snakes would have had the longest craniovertebral muscle, M. rectus capitis anterior, that is elongated only by several segments compared with that of quadrupedal squamates. Therefore, even such a posteriorly displaced “cervical” characteristic plesiomorphically lies fairly anteriorly in the greatly elongated precloacal region of snakes, suggesting that the trunk, not the neck, would have contributed most to the elongation of the snake precloacal region. A similar dissociation of structures usually associated with the neck–trunk boundary in quadrupedal squamates is observed in limb‐reduced squamates, suggesting that these forms and snakes may share a developmental mechanism producing modifications in the anterior–posterior patterning associated with body elongation. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.
Ameliorative effect of α‐tocopherol on monosodium glutamate‐induced cardiac histological alterations and oxidative stress
Authors: Paul Sauganth , Mohanan Abhilash , Varghese Mathews V , Alex Manju , Nair Harikumaran 
Published: May 2012

AbstractBACKGROUND: Chronic oral intake of high doses of monosodium glutamate (MSG) causes oxidative stress. Oxidative stress plays an important role in the development of cardiac dysfunction and injury. Supplementation with α‐tocopherol protects the body against oxidative stress and its related complications. This study was proposed to examine the protective effect of α‐tocopherol against MSG‐induced biochemical and histological alterations in blood and cardiac tissue of rats for a period of 180 days.RESULTS: Chronic oral administration of MSG (4 g kg−1) caused oxidative stress that was manifested by significant increase (P < 0.05) in malondialdehyde, conjugated dienes and by the decrease in the activities of superoxide dismutase, catalase, reduced glutathione, glutathione peroxidase and glutathione S‐transferase in cardiac tissue. The significantly increased (P < 0.05) activities of aspartate transaminase, creatine phosphokinase and lactate dehydrogenase in serum suggested a cardiac functional disorder. Moreover, heart muscle fibers showed cloudy swelling, fiber separation and vascular congestion. Administration of α‐tocopherol (200 mg kg−1) significantly (P < 0.05) attenuated the MSG‐induced biochemical alterations in serum and cardiac tissue. α‐Tocopherol also prevented the pathological changes in cardiac tissue when compared with the MSG‐treated group.CONCLUSION: Our findings suggest that α‐tocopherol may have a protective effect against MSG‐induced cardiotoxicity, possibly through its antioxidant activity. Copyright © 2012 Society of Chemical Industry
Kinetics of the brominated alkyl radical (CHBr2, CH3CHBr) reactions with NO2 in the temperature range 250–480 K
Authors: Rissanen Matti P. , Eskola Arkke J. , Timonen Raimo S. 
Published: April 2012

AbstractThe gas‐phase kinetics of CHBr2 + NO2 and CH3CHBr + NO2 reactions have been studied in direct time resolved measurements using a tubular flow reactor coupled to a photoionization mass spectrometer. The radicals were generated by pulsed laser photolysis of bromoform and 1,1‐dibromoethane at 248 nm. The subsequent decays of the radical concentrations were monitored as a function of [NO2] under pseudo–first‐order conditions. The rate coefficients of both reactions are independent of bath gas (He) pressure and display negative temperature dependence under the conditions of 2–6 Torr pressure (He) and 250–480 K. The obtained bimolecular rate coefficients are k(CHBr2 + NO2) = (9.8 ± 0.4) × 10−12 (T/300 K)−1.65 ± 0.18 cm3 s−1 (288–483 K) and k(CH3CHBr + NO2) = (2.27 ± 0.06) × 10−11 (T/300 K)−1.28 ± 0.11 cm3 s−1 (250–483 K), with the uncertainties given as one standard error. Estimated overall uncertainties in the measured bimolecular reaction rate coefficients are ±25%. The reaction products identified were CBr2O for the CHBr2 + NO2 reaction and CHBrO and CH3CHO with minor amounts of CH3 for the CH3CHBr + NO2 reaction, respectively. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 767–777, 2012
Laser Cutting Technology — A Commercial Perspective
Authors: Powell John , Kaplan Alexander F. H. 
Published: May 2012

AbstractSince the advent of commercial fibre and disk laser cutting machines there has been a lot of controversy about the performance of these devices – particularly in comparison to their more established CO2 counterparts. In the early days the sales staff promoting fibre technology would often declare that the new lasers would completely take over from CO2 technology very quickly – but this has not happened. Even taking into account the entrenched position of the older technology, fibre and disk lasers have not been as widely accepted as was predicted, although they have been proven to outperform CO2 lasers in certain important areas.This article presents a discussion of the advantages and disadvantages of both types of cutting technology from a commercial point of view – written from the perspective of a laser cutting jobshop owner trying to decide between buying a fibre or CO2 laser cutting machine.
Perfect Precision in Industrial Micro Machining
Authors: Heckl Oliver H. , Siebert Christof , Sutter Dirk , Kleinbauer Jochen , Bauer Dominik 
Published: May 2012

AbstractIndustrial applications have driven the commercial laser market for decades. The widespread usage of CW lasers in welding and cutting, in particular at kilowatt average powers, is complemented by the success of pulsed lasers in applications where excessive heat is undesired and where sublimation rather than melting provides ultimate precision in manufacturing. During the past years, ultrafast lasers have become established industrial tools for cold, yet efficient micro machining. They nowadays provide the desired tens of megawatt peak powers at average powers of several tens of watts as required to reach sufficient productivity, at a total cost of ownership below 10 cent (€ or $) per watt and hour of operation. TRUMPF has pioneered ultrafast machining with new lasers based on Yb:YAG disk modules since the beginning of this millennium. This article gives a brief review of the state of the art of ultrafast disk lasers, amplifiers and their industrial applications.
Sociolinguistics of Ethnicity in Francophone Louisiana
Authors: Dajko Nathalie 
Published: May 2012

AbstractThe situation of French in Louisiana and its relationship to ethnicity is often presented in an oversimplified way. Misunderstandings of the terms Cajun and Creole tend to lead to a perception that Louisiana Francophone categories are easy to define or correspond simply to language varieties bearing the same names. In fact, historical changes to both Cajun and Creole identities have led to today’s conflation of terms that belies a much more complex state of affairs featuring considerable linguistic diversity. Furthermore, the focus on these two terms has ignored a third group of Francophones, American Indians. Linguistic fieldwork reveals that Cajuns, Creoles, and Indians all express their identities by manipulating the language differently, but that labels given are not always reliable indicators of the type of French spoken.
Hitze weist Magneten die Schaltrichtung
Authors: Nolting Frithjof 
Published: May 2012

AbstractZukünftige magnetische Datenspeicher sollen immer größere Speicherdichten besitzen. Schon jetzt sind Festplatten bereits wahre Wunderwerke der Technik, dennoch werden einzelne Komponenten immer weiter optimiert. Für eine wichtige Komponente, den Schreibkopf, konnte unsere Gruppe vom Paul Scherrer Institut in Villigen in einer internationalen Zusammenarbeit einen neuen Weg aufzeigen: Schreiben von magnetischer Information mit Hilfe eines intensiven Hitzepulses, erzeugt durch einen kurzen Laserblitz. Ein überraschender Effekt, denn wie kann etwas, was keine Richtung aufweist, dem Magneten die Richtung zum Schalten weisen?
Sie sind ganz Ohr
Authors: Rolfs Claus 
Published: May 2012

AbstractDie Ohren von Mensch und Tier sind raffiniert konstruierte Sinnesorgane. Insbesondere ermöglichen sie es, die Richtung zu bestimmen, aus welcher der Schall kommt. Dies ermittelt das Gehirn aus dem kleinen Laufzeitunterschied der Schallwellen zu den beiden Ohren.
Weakly acidic gastroesophageal refluxes are frequently triggers in young children with chronic cough
Authors: Ghezzi Michele , Guida Edoardo , Ullmann Nicola , Sacco Oliviero , Mattioli Girolamo , Jasonni Vincenzo , Rossi Giovanni A. , Silvestri Michela 
Published: May 2012

AbstractObjectiveTo evaluate whether the proportion of acid and weakly acidic refluxes preceding cough bursts could be different in infants, preschool‐ and school‐aged children with chronic, unexplained cough.Patients and MethodsOne hundred six children with unexplained chronic cough, not receiving acid suppressive therapy, underwent impedance–pH monitoring. They were divided into Group A: <2 years (21 pts), Group B: ≥2 to ≤6 years (41 pts), and Group C: >6 years (44 pts). Reflux was defined as acid (pH <4), weakly acidic (WA; pH 4–7), and weakly alkaline (pH >7).Cough episodes were considered temporally associated with gastroesophageal reflux (GER) when occurring within 2 min after a GER episode.ResultsImpedance–pH detected 55.50 (39.00–76.00) reflux episodes/patient with an acid‐to‐WA reflux event ratio of 3.31 (1.55–8.33). This parameter was significantly lower in Group A (1.33 [0.41–3.40]) than in Group B (3.06 [2.00–6.50]; P < 0.05] and Group C (5.09 [2.34–12.43; P < 0.001]). No cough episode was preceded by weakly alkaline refluxes in any patient. During impedance–pH recording, 93 patients (87.7%) had at least one cough episode that had been preceded by impedance refluxes in 83 patients. In this latter group (83 pts), the median number of cough episodes was 12.0 (5.0–25.5), of which 48.15% (30.15–71.43%) were preceded by refluxes; GER‐preceded cough episodes were similar in the three groups. The majority of children had cough episodes preceded by acid refluxes in the total population (78.3%), in Group B (80.5%) and in Group C (93.7%), but not in Group A (40.0%; P < 0.001).ConclusionsIn addition to acid, also a significant proportion of WA GER may precede cough episodes in young children with persistent cough, possibly explaining the inconstant effects of anti‐acid treatment on respiratory symptoms. Pediatr Pulmonol. 2013; 48:295–302. © 2012 Wiley Periodicals, Inc.