bluuebunny/crossref_metadata_2025 huggingface dataset:
Reference Points and Contractual Choices: An Experimental Examination
Authors: Feldman Yuval , Schurr Amos , Teichman Doron
Published: August 2013

This article focuses on the influence of framing on the way people understand their contractual obligations. A large body of both psychological and economic studies suggests that people treat payoffs framed as gains and payoffs framed as losses distinctly. Building on these studies, we hypothesize that the ways parties understand their duties are affected by the way in which they are framed. More specifically, we expect that promisors will tend to adopt a more self‐serving interpretation when they are making decisions in the domain of losses. To test this prediction, we run a series of four experiments that are all based on a between‐subject design. The first two studies utilize experimental surveys that measure and compare participants' attitudes toward a contract interpretation dilemma. The third and fourth studies are incentive‐compatible experiments, in which participants' actual interpretive decisions determine their payoff. All four experiments confirm our basic hypothesis and show that framing contractual payoffs as losses rather than as gains raises parties' tendency to interpret their obligations selfishly. These findings refine some of the previous understanding regarding the ability of penalties to optimize parties' contractual behavior, especially in situations in which monitoring is limited. Based on these findings, the article revisits some of the basic questions of contract law, shedding new light on an array of issues such as the law of liquidated damages and the optimal design of contracts.
Development of a selective and differential medium for capsulated Lactococcus garvieae
Authors: Chang C‐I , Lee C‐F , Tsai J‐M , Wu C‐C , Chen L‐H , Chen S‐C , Lin K‐J
Published: August 2013

A selective and differential medium termed ‘LG agar’ was developed for the isolation and presumptive identification of Lactococcus garvieae that results in black colonies with red halos. In this study, all 14 strains of L. garvieae and only 9 of the 148 strains representing 38 other species were able to grow on the LG agar. The nine viable strains on LG agar plates (including Enterococcus faecalis, Enterococcus faecium, Lactococcus lactis, Vibrio fluvialis, Vibrio furnissii, Vibrio mimicus and Vibrio salmonicida) were further differentiated from L. garvieae by various colours or colony features. Colonies isolated from the mixing culture and the infected giant sea perch using LG agar plates were all positively identified as L. garvieae by conventional tests and 16S rDNA sequencing. Furthermore, LG agar discriminated capsulated strains of L. garvieae, which were believed to be correlated with pathogens of fish and shellfish, from non‐capsulated ones by colony appearances. The specificity and differentiating ability of LG agar suggest that this medium displays considerable potential for primary isolation and presumptive identification of L. garvieae from pathological and environmental samples.
Hypothalamic Agouti‐Related Protein Expression Is Affected by Both Acute and Chronic Experience of Food Restriction and Re‐Feeding in Chickens
Authors: Dunn I. C. , Wilson P. W. , Smulders T. V. , Sandilands V. , D'Eath R. B. , Boswell T.
Published: August 2013

The central melanocortin system is conserved across vertebrates. However, in birds, little is known about how energy balance influences orexigenic agouti‐related protein (AGRP) and anorexigenic pro‐opiomelanocortin (POMC) expression, despite the fact that commercial food restriction is critical to the efficient production of poultry meat. To enable contrasts to be made, in broiler‐breeder chickens, between levels of food restriction, between birds with the same body weight but different feeding experience, and between birds moved from restricted feeding to ad lib. feeding for different periods, five groups of hens were established between 6 and 12 weeks of age with different combinations of food restriction and release from restriction. AGRP and neuropeptide Y expression in the basal hypothalamus was significantly increased by chronic restriction but only AGRP mRNA levels reflected recent feeding experience: hens at the same body weight that had recently been on ad lib. feeding showed lower expression than restricted birds. AGRP expression also distinguished between hens released from restriction to ad lib. feeding for different periods. By contrast, POMC and cocaine‐ and amphetamine‐regulated transcript mRNA levels were not different. These results showed that AGRP mRNA not only reflected differences between a bird's weight and its potential weight or set point, but also discriminated between differing feeding histories of birds at the same body weight. Therefore, AGRP expression potentially provides an integrated measure of food intake experience and an objective tool to assess a bird's perception of satiety in feeding regimes for improved poultry welfare.
Comparison of a Safety Strategy Using Transradial Access and Dual‐Axis Rotational Coronary Angiography with Transfemoral Access and Standard Coronary Angiography
Authors: YASAR AYSE S. , PERINO ALEXANDER C. , DATTILO PHILIP B. , CASSERLY IVAN P. , CARROLL JOHN D. , MESSENGER JOHN C.
Published: August 2013

Objectives

We sought to investigate the radiation exposure and contrast utilization associated with using a strategy of transradial access and rotational angiography (radial‐DARCA) compared to the traditional approach of transfemoral access and standard angiography (femoral‐SA).

Background

There is an increased focus on optimizing patient safety during cardiac catheterization procedures. Professional guidelines have highlighted physician responsibility to minimize radiation doses and contrast volume. Dual axis rotational coronary angiography (DARCA) is the most recently investigated type of rotational angiography. This new technique permits complete visualization of the left or right coronary tree with a single injection, and is felt to reduce contrast and radiation exposure.

Methods

A total of 56 consecutive patients who underwent radial‐DARCA were identified. From the same time period, an age‐ and gender‐matched group of 61 patients who had femoral‐SA were selected for comparison. Total volume of contrast agent used, fluoroscopy time, and 2 measures of radiation dose (dose area product and air kerma) were recorded for each group.

Results

Mean contrast agent use and patient radiation exposure of the radial‐DARCA group were significantly less than that of the femoral‐SA group. There was no significant difference in fluoroscopy time between the 2 groups.

Conclusions

Physicians can successfully employ an innovative safety strategy of transradial access combined with DARCA that is feasible and is associated with lower radiation doses and contrast volume than femoral artery access and traditional coronary angiography approach. (J Interven Cardiol 2013;26:524‐529)
Influence of Renal Sympathetic Denervation on Quality of Life
Authors: DÖRR OLIVER , LIEBETRAU CHRISTOPH , MÖLLMANN HELGE , RIXE JOHANNES , HECKER FRANZISKA , SZARDIEN SEBASTIAN , WILLMER MATTHIAS , HAMM CHRISTIAN , NEF HOLGER M.
Published: August 2013

Background

Therapy‐resistant arterial hypertension causing psychosocial stress and is associated with cardiovascular morbidity and mortality. The aim of the study was to evaluate the effect on quality of life (QoL) in patients with resistant hypertension undergoing renal sympathetic denervation (RSD).

Methods and Results

We analyzed responses to the SF‐36 Quality of Life Questionnaire provided by patients with resistant arterial hypertension after RSD. Thirty consecutive patients from 2 centers were included in this study, from October 2011 until February 2012. The phone interview was performed after the 3‐month follow‐up. A significant reduction (26 ± 13.5 mmHg) in systolic blood pressure (BP) was detected at the 3‐month follow‐up (142.0 ± 15.1 mmHg vs 168.0 ± 13.7 mmHg; P < 0.001). Seventy‐five percent of the patients indicated that their health situation was a lot better (better, 21%; equal to, 4%) 3 months after RSD compared to the time before the therapeutic procedure. Furthermore, the majority of patients felt full of pep (always, 29%; mostly, 58%; quite often, 8%; sometimes, 4%), and full of energy (always, 25%; mostly, 54%; quite often, 16.7%; sometimes, 4.2%) after the procedure. Recipients of RSD indicated that they felt more light and healthy, and nearly all recipients (93%) described a loss of anxiety and indisposition.

Conclusions

This investigation revealed that sufficient BP reduction by RSD and time following therapeutic success lead to significant improvements in patient QoL. (J Interven Cardiol 2013;26:536‐541)
A Comparative Study of Bivalirudin Plus Clopidogrel versus Bivalirudin Plus Prasugrel in Primary Angioplasty Using Propensity Score Matching
Authors: DÍAZ DE LA LLERA LUIS S. , CUBERO GÓMEZ JOSÉ‐M. , RANGEL DIEGO , PAREJO JUAN , ACOSTA JUAN , FERNÁNDEZ‐CISNAL AGUSTÍN , ZAFRA FRANCISCO , BENEZET JAVIER
Published: August 2013

Introduction and Objectives

In primary angioplasty, bivalirudin is superior to treatment with heparin plus glycoprotein inhibitors for reducing cardiovascular events, although bivalirudin increases the risk of stent thrombosis. Our hypothesis is that the use of prasugrel plus bivalirudin in primary angioplasty would reduce stent thrombosis and cardiovascular events.

Method

Consecutive patients with acute ST‐segment elevation myocardial infarction who were treated by primary angioplasty within 12 hours of the onset of symptoms received bivalirudin plus clopidogrel (Group A) or bivalirudin plus prasugrel (Group B). We compared the groups using propensity score matching. The combined end‐point was cardiac death, thrombosis, acute myocardial infarction, and cerebrovascular accident at 30 days.

Results

We assessed 168 patients. The approach was preferentially radial (95.7%). No differences in baseline characteristics were observed between Groups A (n = 70) and B (n = 70). The total mortality and rate of major bleeding complications at 30 days were 0% for both of the groups. The rate of acute and subacute thrombosis was 4.3% in Group A and 0% in Group B (P = 0.08). We observed an increased rate of events in Group A (5.7%) versus Group B (0%) (P = 0.042).

Conclusions

The administration of bivalirudin plus prasugrel in primary percutaneous coronary intervention reduces cardiovascular effects compared to bivalirudin plus clopidogrel without increasing major bleeding complications during the first 30 days following primary angioplasty performed with a preferentially radial approach. (J Interven Cardiol 2013;26:463‐469)
Electronic health records: new opportunities for clinical research
Authors: Coorevits P. , Sundgren M. , Klein G. O. , Bahr A. , Claerhout B. , Daniel C. , Dugas M. , Dupont D. , Schmidt A. , Singleton P. , De Moor G. , Kalra D.
Published: August 2013

Clinical research is on the threshold of a new era in which electronic health records (EHRs) are gaining an important novel supporting role. Whilst EHRs used for routine clinical care have some limitations at present, as discussed in this review, new improved systems and emerging research infrastructures are being developed to ensure that EHRs can be used for secondary purposes such as clinical research, including the design and execution of clinical trials for new medicines. EHR systems should be able to exchange information through the use of recently published international standards for their interoperability and clinically validated information structures (such as archetypes and international health terminologies), to ensure consistent and more complete recording and sharing of data for various patient groups. Such systems will counteract the obstacles of differing clinical languages and styles of documentation as well as the recognized incompleteness of routine records. Here, we discuss some of the legal and ethical concerns of clinical research data reuse and technical security measures that can enable such research while protecting privacy. In the emerging research landscape, cooperation infrastructures are being built where research projects can utilize the availability of patient data from federated EHR systems from many different sites, as well as in international multilingual settings. Amongst several initiatives described, the EHR4CR project offers a promising method for clinical research. One of the first achievements of this project was the development of a protocol feasibility prototype which is used for finding patients eligible for clinical trials from multiple sources.
Core Dimensions of Personality Broadly Account for the Link from Perceived Social Support to Symptoms of Depression and Anxiety
Authors: Lewis Gary J. , Bates Timothy C. , Posthuma Danielle , Polderman Tinca J. C.
Published: August 2013

Specific personality traits and poor social support are risk factors for anxiety and depression. Little work, however, has considered the effects of social support and personality on these aspects of psychopathology simultaneously. We examined whether perceived social support mediates the effects of core personality domains on symptoms of anxiety and depression. Measures of personality (based on the Five‐Factor Model [FFM]), perceived social support, and symptoms of depression and anxiety were collected in a large Dutch adult population‐based sample (n = 555), and, except for depression symptoms, in an independent U.S. adult population‐based sample (n = 511). Path modeling was used to test the effects of FFM traits on symptoms of depression and anxiety, with and without the mediation of perceived social support. Social support showed no link to symptoms of anxiety and only modest links to symptoms of depression when controlling for the FFM traits. Neuroticism had the strongest effect on symptoms of both depression and anxiety, with Extraversion also showing links to symptoms of depression. Social support has limited influence on symptoms of depression, and no effects on anxiety, over and above the effects of personality. Links between social support and anxiety/depression may largely reflect influences of Neuroticism and Extraversion.
Selecting and Retaining Friends on the Basis of Cigarette Smoking Similarity
Authors: DeLay Dawn , Laursen Brett , Kiuru Noona , Salmela‐Aro Katariina , Nurmi Jari‐Erik
Published: August 2013

This study examines whether friend selection, deselection, and socialization differ as a function of the level of cigarette smoking in the friendship group. A total of 1419 students (median age = 16) from upper secondary and vocational schools in Finland were included as targets in the peer network. Targets in the peer network were asked to nominate friends and describe their own cigarette smoking at two time points one year apart. Network analyses revealed similarity arising from selection and deselection on the basis of smoking. Selection effects (i.e., selecting new friends based on similarity) were stronger for adolescents in low‐smoking groups. Deselection effects (i.e., dropping friends based on dissimilarity) were stronger for adolescents in high‐smoking groups.
Selection and Influence Mechanisms Associated With Marijuana Initiation and Use in Adolescent Friendship Networks
Authors: de la Haye Kayla , Green Harold D. , Kennedy David P. , Pollard Michael S. , Tucker Joan S.
Published: August 2013

Friends are thought to influence adolescent drug use. However, few studies have examined the role of drugs in friendship selection, which is necessary to draw sound conclusions about influence. This study applied statistical models for social networks to test the contribution of selection and influence to associations in marijuana use among friends in two large high schools (N = 1,612; M age = 16.4). There was evidence for friend selection based on similar lifetime and current marijuana use at both schools, but friends were found to influence the initiation and frequency of adolescent marijuana use in just one of these schools. There was minimal evidence that peer effects were moderated by personal, school, or family risk factors.
Popularity as an Organizing Factor of Preadolescent Friendship Networks: Beyond Prosocial and Aggressive Behavior
Authors: Logis Handrea A. , Rodkin Philip C. , Gest Scott D. , Ahn Hai‐Jeong
Published: August 2013

This study investigates friendship selection and influence processes in relation to popularity, aggression, and prosociality among 613 fifth graders in 26 classrooms within one academic year. Results showed that youth tended to select their friends based on similarity in popularity more than similarity in aggression or prosociality. Aggressive youths tended to select prosocial peers as friends given similarity in popularity, but prosocial youths did not disproportionately nominate aggressive peers. Socialization within friendships was evident for aggressive and prosocial behavior and popularity. Discussion considers the importance of social status as a grouping mechanism in peer social ecologies, and as a malleable factor that can impact student adjustment.
Peers and the Emergence of Alcohol Use: Influence and Selection Processes in Adolescent Friendship Networks
Authors: Osgood D. Wayne , Ragan Daniel T. , Wallace Lacey , Gest Scott D. , Feinberg Mark E. , Moody James
Published: August 2013

This study addresses not only influence and selection of friends as sources of similarity in alcohol use, but also peer processes leading drinkers to be chosen as friends more often than nondrinkers, which increases the number of adolescents subject to their influence. Analyses apply a stochastic actor‐based model to friendship networks assessed five times from 6th through 9th grades for 50 grade cohort networks in Iowa and Pennsylvania, which include 13,214 individuals. Results show definite influence and selection for similarity in alcohol use, as well as reciprocal influences between drinking and frequently being chosen as a friend. These findings suggest that adolescents view alcohol use as an attractive, high‐status activity and that friendships expose adolescents to opportunities for drinking.
Onset to First Alcohol Use in Early Adolescence: A Network Diffusion Model
Authors: Light John M. , Greenan Charlotte C. , Rusby Julie C. , Nies Kimberley M. , Snijders Tom A. B.
Published: August 2013

A novel version of Snijders's stochastic actor‐based modeling (SABM) framework is applied to model the diffusion of first alcohol use through middle school–wide longitudinal networks of early adolescents, aged approximately 11–14 years. Models couple a standardSABMfor friendship network evolution with a proportional hazard model for first alcohol use. Meta‐analysis of individual models for 12 schools found significant effects for friendship selection based on the same alcohol use status and for an increased rate of onset to first use based on exposure to already‐onset peers. Onset rate was greater at higher grades and among participants who spent more unsupervised time with friends. Neither selection nor exposure effects interacted with grade, adult supervision, or gender.
Stochastic Agent‐Based Modeling of Influence and Selection in Adolescence: Current Status and Future Directions in Understanding the Dynamics of Peer Contagion
Authors: Dishion Thomas J.
Published: August 2013

This commentary focuses on the theoretical issues raised in this special issue. It is argued that both selection and influence in peer social networks reflect a process of peer contagion. The findings from the special issue studies are briefly reviewed. Some suggestions for future research are made, including the use of multilevel models that integrate interpersonal dynamics with peer network change as well as the use of natural and randomized experimentation to test hypotheses regarding the influence of contexts such as schools on the formation of peer networks. It is hoped that research on peer network can eventually be applied to the design of environments that promote a variety of health behaviors and peer support.
A NOTE ON THE DIFFERENTIAL REGIONAL EFFECTS OF INCOME INEQUALITY: EMPIRICAL EVIDENCE USING U.S. COUNTY‐LEVEL DATA
Authors: Atems Bebonchu
Published: August 2013

This note examines the correlation between income inequality and economic growth using a panel of income distribution data for 3,109 counties of the U.S. Using the System Generalized Method of Moments (GMM) approach, we find that for the entire sample of 3,109 counties, an increase in a county's level of inequality has a significant negative relationship with future economic growth. In reality, however, the magnitude, sign, and significance of this relationship is not necessarily uniform across all regions of the U.S., motivating the need to examine regional differentials in the relationship between inequality and growth. Consequently, we split our dataset into metropolitan and nonmetropolitan counties, into the eight Bureau of Economic Analysis regions, and into regions of different political affiliation and economic‐dependence typology. Our results show considerable heterogeneity in the relationship between inequality and growth across these regions.
HLA‐DQ polymorphisms with HBV infection: different outcomes upon infection and prognosis to lamivudine therapy
Authors: Zhang X. , Jia J. , Dong J. , Yu F. , Ma N. , Li M. , Liu X. , Liu W. , Li T. , Liu D.
Published: August 2013

Two recent genome‐wide studies showed that the single‐nucleotide polymorphisms in the HLA‐DQ region (rs2856718 and rs9275572) were associated with chronic hepatitis B virus infection and chronic hepatitis C virus‐associated hepatocellular carcinoma in Japanese patients. We tested the effects of the two single‐nucleotide polymorphisms for all major HBV outcomes and lamivudine treatment in Han Chinese. A total of 1649 samples were enrolled, and peripheral blood samples were collected in this study. The single‐nucleotide polymorphisms in the HLA‐DQ region were genotyped using matrix‐assisted laser desorption/ionization time of flight mass spectrometry. Our study demonstrated the clear relevance of HLA‐DQ rs2856718 and rs9275572 with HBV susceptibility, natural clearance and HBV‐associated HCC. HLA‐DQ rs2856718G and rs9275572A were strongly associated with decreased risk of chronic HBV infection (odds ratio = 0.641; P = 2.64 × 10−4; odds ratio = 0.627, P = 7.22 × 10−5) and HBV natural clearance (odds ratio = 0.610; P = 4.80 × 10−4; odds ratio = 0.714, P = 0.013). Moreover, rs9275572A was also associated with development of cirrhosis and hepatocellular carcinoma (odds ratio = 0.632, P = 0.008). In addition, we showed for the first time to our knowledge that rs9275572 was a predictor for lamivudine therapy (viral response: odds ratio = 2.599, P = 4.43 × 10−4; biochemical response: odds ratio = 2.279, P = 4.23 × 10−4). Our study suggested that HLA‐DQ loci were associated with both HBV clearance and HBV‐related diseases and outcomes of lamivudine treatment in Han Chinese.
Pharmacodynamic Evaluation of 4 Angiotensin‐Converting Enzyme Inhibitors in Healthy Adult Horses
Authors: Afonso T. , Giguère S. , Rapoport G. , Berghaus L.J. , Barton M.H. , Coleman A.E.
Published: August 2013

Background

Angiotensin‐converting enzyme (ACE) inhibitors are used in horses with cardiovascular disorders despite the paucity of available data regarding their efficacy.

Hypothesis

The degree of serumACEinhibition varies considerably between drugs.

Animals

Eight healthy adult horses.

Methods

Randomized prospective study. Horses were fasted overnight prior to receiving one of 4ACEinhibitors intragastrically, administered at one of 2 dosages, using a randomized Latin square design (benazepril: 0.5 and 0.25 mg/kg; ramipril: 0.3 and 0.1 mg/kg; quinapril: 0.25 and 0.125 mg/kg; perindopril: 0.1 and 0.05 mg/kg). SerumACEactivity was measured using a kinetic spectrophotometric method.

Results

There was a significant effect of drug and dosage on maximumACEinhibition (Imax),ACEinhibition 24 hours after administration (I24h), and area under the curve (AUC0–48h). Benazepril at 0.5 mg/kg resulted in significantly higherImax(86.9 ± 7.0%) andI24h(60.3 ± 7.9%) compared to the other drugs. There was a significant decrease in indirect blood pressure (BP) over time after administration of each drug, but differences inBPwere not significantly different between drugs. Pharmacodynamic variables measured after administration of benazepril to horses with free access to hay were not significantly different from those obtained after fasting. Administration of benazepril orally once daily for 7 days did not result in a cumulative effect onACEinhibition.

Conclusions and Clinical Importance

Of theACEinhibitors tested, oral benazepril (0.5 mg/kg) is the most effective at inhibiting serumACEactivity in healthy horses.
Neurological Disease in Lambs Associated with Exposure to High Environmental Temperature and Humidity
Authors: Sprake P.M. , Hubertus C. , Bissett W.T. , Porter B.F. , Russell K.E. , Garland T. , Young B.D. , Washburn K.E.
Published: August 2013

Background

We detected a pattern of lambs presenting with hyperthermia and neurological signs during the summer.

Objectives

The main objectives of this study were to compare clinical findings and results of diagnostic testing and to identify a potential etiology.

Animals

Fifteen clinical cases of lambs less than 12 months of age presenting with neurological signs, tachypnea, and hyperthermia over 4 summers.

Methods

Retrospective case series. Medical records were searched for lambs less than 12 months of age that presented with neurological signs including the following: kyphosis, pelvic limb hyperextension, treading of feet, muscle tremors and recumbency, and hyperthermia of greater than 104°F. A grading system was established to describe severity of presenting neurological signs. Weather data were collected from weather stations near the farm of origin for 3 days prior to presentation.

Results

The lambs were from 7 flocks in central Texas. All cases occurred between July and September, with a median heat index of 90.5 for the 3 days before presentation. Complete blood count, serum chemistry, necropsy examination, rumen content, virology, brain MRI, liver copper, selenium, and vitamin E failed to identify a consistent etiology for the signs presented. The only common factor was high heat and humidity. Histopathological examination identified axonal degeneration and skeletal muscle necrosis in some lambs.

Conclusions and Clinical Importance

These clinical cases appeared similar to the Australian disease humpyback and indicate that lambs exposed to high environmental temperatures and humidity might be at risk of developing the described clinical presentation.
Amino Acid, Iodine, Selenium, and Coat Color Status among Hyperthyroid, Siamese, and Age‐Matched Control Cats
Authors: Sabatino B.R. , Rohrbach B.W. , Armstrong P.J. , Kirk C.A.
Published: August 2013

Background

Hyperthyroidism is common among older cats, but its pathogenesis remains poorly understood. Siamese and Himalayan cats have a reduced risk of hyperthyroidism compared with domestic short‐hair cat breeds. A mechanism of risk reduction in pointed‐coat breeds is unknown.

Objectives

To determine if tyrosine, phenylalanine, iodine, or selenium blood concentrations are altered in hyperthyroid cats and to describe the plasma amino acid profiles of client‐owned cats with naturally occurring hyperthyroidism.

Animals

Twenty‐seven client‐owned cats with (n = 12) and without (n = 15) hyperthyroidism were studied.

Methods

Cross‐sectional study. Hyperthyroid cats were prospectively recruited among cats presenting for radioiodine therapy. Control cats were recruited among pets of hospital personnel. Blood was collected for total thyroxine, plasma amino acid, selenium, and iodine determination. Coat color (8 white or pointed; 19 dark), breed, and diet history were recorded.

Results

Tyrosine, phenylalanine, iodine, and selenium levels were not significantly different among light or dark cats or cats with or without hyperthyroidism (P > .05). Plasma amino acid profiles of hyperthyroid cats and control cats were similar, and neither group was deficient in any of the amino acids. l‐glutamine was significantly lower in cats with hyperthyroidism (mean ± SD: 648 ± 193) compared with control cats (816 ± 134; P < .05).

Conclusions and Clinical Importance

Altered tyrosine, iodine, and selenium metabolism were not associated with coat color or hyperthyroidism in pointed or light coat–colored cats.
Ecological determinants of mating system within and between three Fagus sylvatica populations along an elevational gradient
Authors: Gauzere Julie , Klein Etienne K. , Oddou‐Muratorio Sylvie
Published: August 2013

Studies addressing the variation of mating system between plant populations rarely account for the variability of these parameters between individuals within populations, although this variability is often non‐negligible. Here, we propose a new direct method based on paternity analyses (Mixed Effect Mating Model) to estimate individual migration (mi) and selfing rates (si) together with the pollen dispersal kernel. Using this method and the KINDIST approach, we investigated the variation of mating system parameters within and between three populations of Fagus sylvatica along an elevational gradient. Among the mother trees, si varied from 0% to 48%, mi varied from 12% to 86% and the effective number of pollen donors (Nepi) varied from 2 to 364. The mating patterns differed along the gradient, the top population showing higher m and lower s, and a trend to higher Nep than the bottom populations. The phenological lag shaped long‐distance pollen flow both within population (by increasing mi at mother‐tree level) and between populations (by increasing m at high elevation). Rather than the mate density, the canopy density was detected as a major mating system determinant within population; it acted as a barrier to pollen flow, decreasing the proportion of long‐distance pollen flow and increasing si. Overall, the effects of ecological factors on mating system were not the same within vs. between populations across the gradient, and these factors also differed from those traditionally found to shape variation at range‐wide scale, highlighting the interest of multiscale approaches.
Expression of antimicrobial peptides and toll‐like receptors is increased in tinea and pityriasis versicolor
Authors: Brasch J. , Mörig A. , Neumann B. , Proksch E.
Published: August 2013

In superficial tinea and pityriasis versicolor, the causative fungi are for the most part confined to the stratum corneum which is barely reached by leukocytes. Therefore, a role of non‐cellular components in the epidermal antifungal defence was suggested. To investigate the presence of such factors in these infections, the expression of human beta defensins 2 and 3 (hBD‐2, hBD‐3), RNase 7, psoriasin, toll‐like receptors 2, 4 and 9 (TLR2, TLR4 and TLR9) and dectin 2 was analysed by use of immunostainings in skin biopsies. We found that hBD2, hBD3, psoriasin, RNase7, TLR2 and TLR4 were significantly more often expressed in distinct layers of lesional epidermis as compared with uninfected epidermis. In both infections but not in normal skin, hBD2 and hBD3 were commonly expressed within the stratum corneum and in the stratum granulosum. Similarly, psoriasin was seen more often in the upper skin layers of both infections as compared with normal skin. No significant differences between normal and infected skin were found for the expression of TLR9 and dectin 2. Our findings clearly show the expression of specific antimicrobial proteins and defence‐related ligands in superficial tinea as well as in pityriasis versicolor, suggesting that these factors contribute to fungal containment.
Paternal leakage, heteroplasmy, and the evolution of plant mitochondrial genomes
Authors: McCauley David E.
Published: August 2013

Plant mitochondrial genomes are usually transmitted to the progeny from the maternal parent. However, cases of paternal transmission are known and are perhaps more common than once thought. This review will consider recent evidence, both direct and indirect, of paternal transmission (leakage) of the mitochondrial genome of seed plants, especially in natural populations, and how this can result in offspring that carry a mixture of maternally and paternally derived copies of the genome; a type of heteroplasmy. It will further consider how this heteroplasmy facilitates recombination between genetically distinct partners; a process that can enhance mitochondrial genotypic diversity. This will then form the basis for a discussion of five evolutionary questions that arise from these observations. Questions include how plant mitochondrial genome evolution can be placed on a sexual to asexual continuum, whether cytoplasmic male sterility (CMS) facilitates the evolution of paternal leakage, whether paternal leakage is more likely in populations undergoing admixture, how leakage influences patterns of gene flow, and whether heteroplasmy occurs in natural populations at a frequency greater than predicted by crossing experiments. It is proposed that each of these questions offers fertile ground for future research on a diversity of plant species.

Contents

Summary
966

I.
Introduction
966

II.
Indirect and direct evidence for paternal leakage and heteroplasmy
967

III.
Five evolutionary issues raised by these observations
970

IV.
Conclusions
975

Acknowledgements
975

References
975
A novel role of PR2 in abscisic acid (ABA) mediated, pathogen‐induced callose deposition in Arabidopsis thaliana
Authors: Oide Shinichi , Bejai Sarosh , Staal Jens , Guan Na , Kaliff Maria , Dixelius Christina
Published: August 2013

Pathogenesis‐related protein 2 (PR2) is known to play a major role in plant defense and general stress responses. Resistance against the fungal pathogen Leptosphaeria maculans in Arabidopsis requires abscisic acid (ABA), which promotes the deposition of callose, a β‐1,3‐glucan polymer. Here, we examined the role of PR2 in callose deposition in relation to ABA treatment and challenge with L. maculans and Pseudomonas syringae.

Characterization of PR2‐overexpressing plants and the knockout line indicated that PR2 negatively affects callose deposition. Recombinant PR2 purified from Pichia pastoris showed callose‐degrading activity, and a considerable reduction in the callose‐degrading activity was observed in the leaf extract of the PR2 knockout line compared with the wild‐type.

ABA pretreatment before challenge with L. maculans concomitantly repressed PR2 and enhanced callose accumulation. Likewise, overexpression of an ABA biosynthesis gene NCED3 resulted in reduced PR2 expression and increased callose deposition.

We propose that ABA promotes callose deposition through the transcriptional repression of PR2 in Arabidopsis challenged by L. maculans and P. syringae. Callose by itself is likely to act antagonistically on salicylic acid (SA) defense signaling, suggesting that PR2 may function as a modulator of callose‐ and SA‐dependent defense responses.
Gene networks controlling Arabidopsis thaliana flower development
Authors: Ó'Maoiléidigh Diarmuid Seosamh , Graciet Emmanuelle , Wellmer Frank
Published: August 2013

The formation of flowers is one of the main models for studying the regulatory mechanisms that underlie plant development and evolution. Over the past three decades, extensive genetic and molecular analyses have led to the identification of a large number of key floral regulators and to detailed insights into how they control flower morphogenesis. In recent years, genome‐wide approaches have been applied to obtaining a global view of the gene regulatory networks underlying flower formation. Furthermore, mathematical models have been developed that can simulate certain aspects of this process and drive further experimentation. Here, we review some of the main findings made in the field of Arabidopsis thaliana flower development, with an emphasis on recent advances. In particular, we discuss the activities of the floral organ identity factors, which are pivotal for the specification of the different types of floral organs, and explore the experimental avenues that may elucidate the molecular mechanisms and gene expression programs through which these master regulators of flower development act.

Contents

Summary
16

I.
Introduction
16

II.
Initiation of flower development
17

III.
Specification of floral organs: the ABCE model
18

IV.
Floral patterning: activating the floral organ identity genes in specific domains
19

V.
Mechanistic insights into floral organ identity factor function
21

VI.
Gene expression programs controlled by the floral organ identity factors
23

VII.
Network modeling
26

VIII.
Conclusions
26

Acknowledgements
27

References
27
SWEET sugar transporters for phloem transport and pathogen nutrition
Authors: Chen Li‐Qing
Published: August 2013

Many intercellular solute transport processes require an apoplasmic step, that is, efflux from one cell and subsequent uptake by an adjacent cell. Cellular uptake transporters have been identified for many solutes, including sucrose; however, efflux transporters have remained elusive for a long time. Cellular efflux of sugars plays essential roles in many processes, such as sugar efflux as the first step in phloem loading, sugar efflux for nectar secretion, and sugar efflux for supplying symbionts such as mycorrhiza, and maternal efflux for filial tissue development. Furthermore, sugar efflux systems can be hijacked by pathogens for access to nutrition from hosts. Mutations that block recruitment of the efflux mechanism by the pathogen thus cause pathogen resistance. Until recently, little was known regarding the underlying mechanism of sugar efflux. The identification of sugar efflux carriers, SWEETs (Sugars Will Eventually be Exported Transporters), has shed light on cellular sugar efflux. SWEETs appear to function as uniporters, facilitating diffusion of sugars across cell membranes. Indeed, SWEETs probably mediate sucrose efflux from putative phloem parenchyma into the phloem apoplasm, a key step proceeding phloem loading. Engineering of SWEET mutants using transcriptional activator‐like effector nuclease (TALEN)‐based genomic editing allowed the engineering of pathogen resistance. The widespread expression of the SWEET family promises to provide insights into many other cellular efflux mechanisms.
Function of isoamylase‐type starch debranching enzymes ISA1 and ISA2 in the Zea mays leaf
Authors: Lin Qiaohui , Facon Maud , Putaux Jean‐Luc , Dinges Jason R. , Wattebled Fabrice , D'Hulst Christophe , Hennen‐Bierwagen Tracie A. , Myers Alan M.
Published: August 2013

Conserved isoamylase‐type starch debranching enzymes (ISAs), including the catalytic ISA1 and noncatalytic ISA2, are major starch biosynthesis determinants. Arabidopsis thaliana leaves require ISA1 and ISA2 for physiological function, whereas endosperm starch is near normal with only ISA1. ISA functions were characterized in maize (Zea mays) leaves to determine whether species‐specific distinctions in ISA1 primary structure, or metabolic differences in tissues, are responsible for the differing ISA2 requirement.

Genetic methods provided lines lacking ISA1 or ISA2. Biochemical analyses characterized ISA activities in mutant tissues. Starch content, granule morphology, and amylopectin fine structure were determined.

Three ISA activity forms were observed in leaves, two ISA1/ISA2 heteromultimers and one ISA1 homomultimer. ISA1 homomultimer activity existed in mutants lacking ISA2. Mutants without ISA2 differed in leaf starch content, granule morphology, and amylopectin structure compared with nonmutants or lines lacking both ISA1 and ISA2. The data imply that both the ISA1 homomultimer and ISA1/ISA2 heteromultimer function in the maize leaf.

The ISA1 homomultimer is present and functions in the maize leaf. Evolutionary divergence between monocots and dicots probably explains the ability of ISA1 to function as a homomultimer in maize leaves, in contrast to other species where the ISA1/ISA2 heteromultimer is the only active form.
European deciduous trees exhibit similar safety margins against damage by spring freeze events along elevational gradients
Authors: Lenz Armando , Hoch Günter , Vitasse Yann , Körner Christian
Published: August 2013

Minimum temperature is assumed to be an important driver of tree species range limits. We investigated during which period of the year trees are most vulnerable to freezing damage and whether the pressure of freezing events increases with increasing elevation.

We assessed the course of freezing resistance of buds and leaves from winter to summer at the upper elevational limits of eight deciduous tree species in the Swiss Alps. By reconstructing the spring phenology of these species over the last eight decades using a thermal time model, we linked freezing resistance with long‐term minimum temperature data along elevational gradients.

Counter‐intuitively, the pressure of freeze events does not increase with elevation, but deciduous temperate tree species exhibit a constant safety margin (5–8.5 K) against damage by spring freeze events along elevational gradients, as a result of the later flushing at higher elevation. Absolute minimum temperatures in winter and summer are unlikely to critically injure trees.

Our study shows that freezing temperatures in spring are the main selective pressure controlling the timing of flushing, leading to a shorter growing season at higher elevation and potentially driving species distribution limits. Such mechanistic knowledge is important to improve predictions of tree species range limits.
Scale dependence in the effects of leaf ecophysiological traits on photosynthesis: Bayesian parameterization of photosynthesis models
Authors: Feng Xiaohui , Dietze Michael
Published: August 2013

Relationships between leaf traits and carbon assimilation rates are commonly used to predict primary productivity at scales from the leaf to the globe. We addressed how the shape and magnitude of these relationships vary across temporal, spatial and taxonomic scales to improve estimates of carbon dynamics.

Photosynthetic CO2 and light response curves, leaf nitrogen (N), chlorophyll (Chl) concentration and specific leaf area (SLA) of 25 grassland species were measured. In addition, C3 and C4 photosynthesis models were parameterized using a novel hierarchical Bayesian approach to quantify the effects of leaf traits on photosynthetic capacity and parameters at different scales.

The effects of plant physiological traits on photosynthetic capacity and parameters varied among species, plant functional types and taxonomic scales. Relationships in the grassland biome were significantly different from the global average. Within‐species variability in photosynthetic parameters through the growing season could be attributed to the seasonal changes of leaf traits, especially leaf N and Chl, but these responses followed qualitatively different relationships from the across‐species relationship.

The results suggest that one broad‐scale relationship is not sufficient to characterize ecosystem condition and change at multiple scales. Applying trait relationships without articulating the scales may cause substantial carbon flux estimation errors.
The use of a double‐lumen central venous catheter for airway management in pediatric patients undergoing laryngeal papillomatosis surgery
Authors: Zhu Zhi‐rui , Hu Zhi‐yong , Jiang Yi‐lei , Xu Li‐li , McQuillan Patrick M.
Published: August 2013

Purpose

To evaluate the efficacy and safety of a spontaneous ventilation anesthesia technique with insufflation of oxygen and volatile agent through a double‐lumen central venous catheter (DLCVC) in pediatric patients undergoing suspension laryngoscopic surgery for laryngeal papillomatosis.

Methods

Thirty‐six pediatric patients with laryngeal papillomatosis undergoing suspension laryngoscopic surgery were anesthetized with oxygen and volatile anesthetic insufflation while spontaneously breathing. Anesthesia was induced by inhalation of 8% sevoflurane in oxygen by mask. Atropine, dexamethasone, lidocaine, and midazolam were administered intravenously. The tip of a 7Fr DLCVC was inserted below the glottis after placement of the laryngoscope and establishing suspension. Anesthesia was maintained with insufflation of 4–6% sevoflurane and oxygen with a total fresh gas flow of 6 l·min−1 through the 14G (larger lumen) of the DLCVC. Endtidal carbon dioxide tension (PetCO2) was monitored using the other lumen of the DLCVC, which was connected to the CO2 sampling line. Duration of the procedure as well as total anesthesia time was recorded. Electrocardiography (ECG), heart rate (HR), mean arterial pressure (MAP), oxygen saturation (SpO2), and PetCO2 were also monitored. Arterial blood was sampled for blood gas analysis including pH, PaO2, PaCO2, and actual base excess (ABE). Complications, including intraoperative patient movement, hypoxemia (SpO2 < 95% during oxygen insufflation), nausea, vomiting, bronchospasm, and arrhythmias, were recorded.

Results

There was a significant increase in PetCO2 and PaCO2 (P values <0.05) as well as a decrease in ABE, pH, and PaO2 (P values <0.05) in samples collected before and after surgery. MAP, HR, and SpO2 after surgery were not significantly different from after induction values (P values >0.05). During surgery, SpO2 < 95% in three cases and body movements in three cases were observed. No patient had any other of the complications previously described. Furthermore, no postsurgical endotracheal intubation was needed in any patient.

Conclusion

After establishing an adequate depth of anesthesia, a spontaneous ventilation anesthesia technique with insufflation of oxygen and volatile agent through a DLCVC is feasible in pediatric patients undergoing suspension laryngoscopic surgery for laryngeal papillomatosis.
Unreliable Knowledge
Authors: Turri John
Published: August 2013

There is a virtual consensus in contemporary epistemology that knowledge must be reliably produced. Everyone, it seems, is a reliabilist about knowledge in that sense. I present and defend two arguments that unreliable knowledge is possible. My first argument proceeds from an observation about the nature of achievements, namely, that achievements can proceed from unreliable abilities. My second argument proceeds from an observation about the epistemic efficacy of explanatory inference, namely, that inference to the best explanation seems to produce knowledge, even if it isn't reliable. I also propose a successor to standard versions of reliabilism, which I call ‘ecumenical reliabilism’. Ecumenical reliabilism is consistent with unreliably produced knowledge and helps explain why unreliably produced knowledge is possible.