bluuebunny/crossref_metadata_2025 huggingface dataset:
What Is Trust?
Authors: Simpson Thomas W.
Published: October 2012

Trust is difficult to define. Instead of doing so, I propose that the best way to understand the concept is through a genealogical account. I show how a root notion of trust arises out of some basic features of what it is for humans to live socially, in which we rely on others to act cooperatively. I explore how this concept acquires resonances of hope and threat, and how we analogically apply this in related but different contexts. The genealogical account explains both why the notion has such value for us and why it is difficult to define.
Soil biotic impact on plant species shoot chemistry and hyperspectral reflectance patterns
Authors: Carvalho Sabrina , Macel Mirka , Schlerf Martin , Skidmore Andrew K. , van der Putten Wim H.
Published: October 2012

Recent studies revealed that plant–soil biotic interactions may cause changes in above‐ground plant chemistry. It would be a new step in below‐ground–above‐ground interaction research if such above‐ground chemistry changes could be efficiently detected. Here we test how hyperspectral reflectance may be used to study such plant–soil biotic interactions in a nondestructive and rapid way.

The native plant species Jacobaea vulgaris and Jacobaea erucifolius, and the exotic invader Senecio inaequidens were grown in different soil biotic conditions. Biomass, chemical content and shoot reflectance between 400 and 2500 nm wavelengths were determined. The data were analysed with multivariate statistics.

Exposing the plants to soil biota enhanced the content of defence compounds. The highest increase (400%) was observed for the exotic invader S. inaequidens. Chemical and spectral data enabled plant species to be classified with an accuracy > 85%. Plants grown in different soil conditions were classified with 50–60% correctness.

Our data suggest that soil microorganisms can affect plant chemistry and spectral reflectance. Further studies should test the potential to study plant–soil biotic interactions in the field. Such techniques could help to monitor, among other things, where invasive exotic plant species develop biotic resistance or the development of hotspots of crop soil diseases.
The genetic basis for natural variation in heteroblasty in Antirrhinum
Authors: Costa M. Manuela R. , Yang Suxin , Critchley Joanna , Feng Xianzhong , Wilson Yvette , Langlade Nicolas , Copsey Lucy , Hudson Andrew
Published: October 2012

Heteroblasty refers to the changes in leaf shape and size (allometry) along stems. Although evolutionary changes involving heteroblasty might contribute to leaf diversity, little is known of the extent to which heteroblasty differs between species or how it might relate to other aspects of allometry or other developmental transitions.

Here, we develop a computational model that can quantify differences in leaf allometry between Antirrhinum (snapdragon) species, including variation in heteroblasty. It allows the underlying genes to be mapped in inter‐species hybrids, and their effects to be studied in similar genetic backgrounds.

Heteroblasty correlates with overall variation in leaf allometry, so species with smaller, rounder leaves produce their largest leaves earlier in development. This involves genes that affect both characters together and is exaggerated by additional genes with multiplicative effects on leaf size. A further heteroblasty gene also alters leaf spacing, but none affect other developmental transitions, including flowering.

We suggest that differences in heteroblasty have co‐evolved with overall leaf shape and size in Antirrhinum because these characters are constrained by common underlying genes. By contrast, heteroblasty is not correlated with other developmental transitions, with the exception of internode length, suggesting independent genetic control and evolution.
Risk of developmental delay increases exponentially as gestational age of preterm infants decreases: a cohort study at age 4 years
Authors: KERSTJENS JORIEN M , DE WINTER ANDREA F , BOCCA‐TJEERTES INGER F , BOS AREND F , REIJNEVELD SIJMEN A
Published: October 2012

Aim  The aim of the study was to assess the influence of decreasing gestational age on the risk of developmental delay in various domains at age 4 years among children born at a wide range of gestational ages.

Method  In a community‐based cohort, the parents of 1439 preterm‐born children (24 0/7 to 35 6/7wks) and 544 term‐born children (38 0/7 to 41 6/7wks’) born in 2002 and 2003 completed the Ages and Stages Questionnaire (ASQ) when their child was 3 years 7 months to 4 years 1 month old. The prevalence rates of abnormal scores on the ASQ‐total problems scale were compared in preterm and term‐born children and the resulting odds ratios for gestational age groups were calculated and adjusted for social and biological covariates.

Results  The prevalence rates of abnormal scores on the ASQ‐total problems scale increased with decreasing gestational age: from 4.2% among term‐born children to 37.5% among children born at 24–25 weeks’ gestation (p<0.001). The risk of an abnormal ASQ‐total score increased exponentially with decreasing gestational age compared with children born at term (odds ratio per week of gestation 1.14, 95% confidence interval 1.09–1.19). A similar exponential pattern was seen on all underlying ASQ domains, both before and after adjustment.

Interpretation  The risk of developmental delay increases exponentially with decreasing gestational age below 36 weeks’ gestation on all developmental domains of the ASQ. Adjustment for covariates did not alter the pattern of exponential increase in developmental risk with decreasing gestational age. We speculate that both direct perinatal cerebral injuries and tropic and maturational brain disturbances are involved.
Do Earnings Targets and Managerial Incentives Affect Sticky Costs?
Authors: KAMA ITAY , WEISS DAN
Published: October 2012

This study explores motivations underlying managers’ resource adjustments. We focus on the impact of incentives to meet earnings targets on resource adjustments and the ensuing cost structures. We find that, when managers face incentives to avoid losses or earnings decreases, or to meet financial analysts’ earnings forecasts, they expedite downward adjustment of slack resources for sales decreases. These deliberate decisions lessen the degree of cost stickiness rather than induce cost stickiness. The results suggest that efforts to understand determinants of firms’ cost structures should be made in light of the managers’ motivations, particularly agency‐driven incentives underlying resource adjustment decisions.
Does Stress Increase Imitation of Drinking Behavior? An Experimental Study in a (Semi‐)Naturalistic Context
Authors: Larsen Helle , Engels Rutger C. M. E. , Granic Isabela , Huizink Anja C.
Published: October 2012

Background

That alcohol consumption is strongly influenced by the drinking behavior of social company has been demonstrated in observational research. However, not everyone is equally vulnerable to other people's drinking, and it is important to unravel which factors underlie these individual differences. This study focuses on the role of psychosocial stress in attempting to explain individual differences in the propensity to imitate alcohol consumption.

Methods

With a 2 (confederate's drinking condition: alcohol vs. soda) × 2 (participant's stress condition: stress vs. no stress) experimental design, we tested whether the tendency to imitate other people's drinking was related to participants' induced stress levels. The young male adults (N = 106) were randomly assigned to each of the conditions. In each session, directly after the stress or no‐stress period, confederates and participants entered a bar laboratory where we observed their drinking behavior. Prior to entering the session, confederates were instructed to drink alcohol or soda.

Results

Participants in both stress and no‐stress conditions consumed substantially more alcohol when confederates drank alcohol than when they drank soda. There was no difference in alcohol consumed between stress and no‐stress conditions. No moderating effect of stress on the tendency to drink along with peers was found.

Conclusions

Generally, it appears that among young male adults, imitation of alcohol consumption is a robust phenomenon not dependent on individual stress levels.
Time‐Varying Latent Effect Model for Longitudinal Data with Informative Observation Times
Authors: Cai Na , Lu Wenbin , Zhang Hao Helen
Published: October 2012

Summary In analysis of longitudinal data, it is not uncommon that observation times of repeated measurements are subject‐specific and correlated with underlying longitudinal outcomes. Taking account of the dependence between observation times and longitudinal outcomes is critical under these situations to assure the validity of statistical inference. In this article, we propose a flexible joint model for longitudinal data analysis in the presence of informative observation times. In particular, the new procedure considers the shared random‐effect model and assumes a time‐varying coefficient for the latent variable, allowing a flexible way of modeling longitudinal outcomes while adjusting their association with observation times. Estimating equations are developed for parameter estimation. We show that the resulting estimators are consistent and asymptotically normal, with variance–covariance matrix that has a closed form and can be consistently estimated by the usual plug‐in method. One additional advantage of the procedure is that it provides a unified framework to test whether the effect of the latent variable is zero, constant, or time‐varying. Simulation studies show that the proposed approach is appropriate for practical use. An application to a bladder cancer data is also given to illustrate the methodology.
A Low Sintering Temperature Low Loss Microwave Dielectric Material ZnZrNb2O8
Authors: Liao Qingwei , Li Lingxia , Ren Xiang , Yu Xiaoxu , Guo Dong , Wang Mingjing
Published: October 2012

A low sintering temperature microwave dielectric material ZnZrNb2O8 was reported. It exhibits a monoclinic structure, belongs to the space group P2/c (C2h4), and Z = 1. The dielectric constant increased with increasing relative density. The Qf value increased with increasing packing fraction. The τf increased with increasing dielectric constant. The typical values of ZnZrNb2O8 were ε = 30, Qf = 61 000 GHz, τf=−52 × 10−6 °C−1, sintered at 950°C.
Genetic variation in DNMT3B and increased global DNA methylation is associated with suicide attempts in psychiatric patients
Authors: Murphy T. M. , Mullins N. , Ryan M. , Foster T. , Kelly C. , McClelland R. , O'Grady J. , Corcoran E. , Brady J. , Reilly M. , Jeffers A. , Brown K. , Maher A. , Bannan N. , Casement A. , Lynch D. , Bolger S. , Buckley A. , Quinlivan L. , Daly L. , Kelleher C. , Malone K. M.
Published: October 2012

Recently, a significant epigenetic component in the pathology of suicide has been realized. Here we investigate candidate functional SNPs in epigenetic‐regulatory genes, DNMT1 and DNMT3B, for association with suicide attempt (SA) among patients with co‐existing psychiatric illness. In addition, global DNA methylation levels [5‐methyl cytosine (5‐mC%)] between SA and psychiatric controls were quantified using the Methylflash Methylated DNA Quantification Kit. DNA was obtained from blood of 79 suicide attempters and 80 non‐attempters, assessed for DSM‐IV Axis I disorders. Functional SNPs were selected for each gene (DNMT1; n = 7, DNMT3B; n = 10), and genotyped. A SNP (rs2424932) residing in the 3′ UTR of the DNMT3B gene was associated with SA compared with a non‐attempter control group (P = 0.001; Chi‐squared test, Bonferroni adjusted P value = 0.02). Moreover, haplotype analysis identified a DNMT3B haplotype which differed between cases and controls, however this association did not hold after Bonferroni correction (P = 0.01, Bonferroni adjusted P value = 0.56). Global methylation analysis showed that psychiatric patients with a history of SA had significantly higher levels of global DNA methylation compared with controls (P = 0.018, Student's t‐test). In conclusion, this is the first report investigating polymorphisms in DNMT genes and global DNA methylation quantification in SA risk. Preliminary findings suggest that allelic variability in DNMT3B may be relevant to the underlying diathesis for suicidal acts and our findings support the hypothesis that aberrant DNA methylation profiles may contribute to the biology of suicidal acts. Thus, analysis of global DNA hypermethylation in blood may represent a biomarker for increased SA risk in psychiatric patients.
Effectiveness of an educational intervention to improve child feeding practices and growth in rural China: updated results at 18 months of age
Authors: Zhang Jingxu , Shi Ling , Chen Da‐fang , Wang Jing , Wang Yan
Published: October 2012

Inappropriate complementary feeding practices have led to, in part, significant disparities in growth and nutritional status between rural and urban children in China. A cluster‐randomised, controlled trial was implemented in Laishui, China to assess the effectiveness of an educational intervention on caregivers' feeding practices and children's growth. Eight townships were randomly assigned to the intervention or control. Five hundred ninety‐nine healthy infants were enrolled at 2–4 months old, and were followed up at ages 6, 9, 12, 15 and 18 months. The intervention group received information on enhanced home‐prepared recipes and food preparation and hygiene through group training, counselling and home visit. Key outcomes were children's physical growth, caregivers' knowledge and behaviours on complementary feeding, and the infant and child feeding index (ICFI). Analysis was by intention to treat. The intervention group achieved better knowledge and practices related to complementary feeding, and significantly higher ICFI scores at each follow‐up point. Children in the intervention group achieved higher z‐scores for weight‐for‐age (WAZ) and weight‐for‐height (WHZ) than the control (0.18 vs. 0.01 and 0.49 vs. 0.19, respectively) at 18 months old, and were less likely to have stunted growth (odds ratio = 0.71, 95% confidence interval: 0.53–0.94). Mixed model showed that the intervention group achieved significantly better linear growth over time, including WAZ (P = 0.016), WHZ (P = 0.030) and HAZ (P = 0.078). These results indicated that an educational intervention delivered through local health services can enhance caregivers' knowledge and practices of complementary feeding and ultimately improve children's growth.
Early growth velocities and weight gain plasticity improve linear growth inPeruvian infants
Authors: Iannotti Lora L. , Zavaleta Nelly , Huasaquiche Clara , Leon Zulema , Caulfield Laura E.
Published: October 2012

Growth velocity patterns have the potential to signal unhealthy responses to environmental insults with long‐term consequences. We aimed to investigate velocities inPeruvian infants (n = 259) in relation to attained anthropometric outcomes at 12 months and to identify determinants of velocities during critical periods of infancy. From 1995 to 1997, a randomised controlled trial of maternal zinc supplementation was conducted in a peri‐urban slum area of Lima. Infants were followed monthly through 1 year on a range of anthropometric measures. Three types of velocity variables were studied: (1)incremental velocity(1 months and 3 months); (2)proportional changes(% of total size gained/month); and (3)individual velocity variability[standard deviation (SD) of individual child incremental velocities]. Mean individual childSDof weight velocity was 417 g (±126). In multivariate ordinary least squares regression analyses, growth velocities in month 1 and individual weight velocity variability positively predicted attained length and weight by 12 months. Panel regression by generalised least‐squares with random effects of length and weight velocities confirmed the exponentially decelerating pace of growth through infancy and the importance of birth size in driving this trajectory. This study contributes evidence to support the importance of early growth velocities and greater degrees of weight gain plasticity for attained length and weight.
Difference between parental perception and actual weight status of children: a systematic review
Authors: Rietmeijer‐Mentink Marloes , Paulis Winifred D. , van Middelkoop Marienke , Bindels Patrick J.E. , van der Wouden Johannes C.
Published: October 2012

An increasing number of children worldwide are overweight, and the first step in treating obesity is to identify overweight. However, do parents recognise overweight in their child and which factors influence parental perception? The aim of the present review is to systematically study differences between parental perception and the actual weight status of children. Medline, EMbase, CINAHL and PsychINFO were searched. After screening 2497 abstracts and 106 full texts, two reviewers independently scored the methodological quality of 51 articles (covering 35 103 children), which fulfilled the inclusion criteria. The primary outcome parameters were sensitivity and specificity of parental perception for actual weight status of their child. The methodological quality of the studies ranged from poor to excellent. Pooled results showed that according to objective criteria 11 530 children were overweight; of these, 7191 (62.4%) were incorrectly perceived as having normal weight by their parents. The misperception of overweight children is higher in parents with children aged 2–6 years compared with parents of older children. Sensitivity (correct perception of overweight) of the studies ranged from 0.04 to 0.89, while specificity (correct perception of normal weight) ranged from 0.86 to 1.00. There were no significant differences in sensitivity or specificity for different cut‐off points for overweight, or between newer and older studies. Therefore we can conclude that parents are likely to misperceive the weight status of their overweight child, especially in children aged 2–6 years. Because appropriate treatment starts with the correct perception of overweight, health care professionals should be aware of the frequent parental misperception of the overweight status of their children.
Conservation genetics of highly isolated populations of the xerothermic beetle Crioceris quatuordecimpunctata (Chrysomelidae)
Authors: Kubisz Daniel , Kajtoch Łukasz , Mazur Miłosz A. , Lis Agata , Holecová Milada
Published: October 2012

Xerothermic species are rare and threatened in central and eastern Europe. In light of the continuing loss of steppe‐like habitats due to anthropogenic fragmentation and degradation, the evaluation of genetic variation in populations inhabiting them is of immediate importance if appropriate conservation measures are to be undertaken. Here we report on the genetic diversity of the rare leaf beetle Crioceris quatuordecimpunctata, whose populations in central and eastern Europe inhabit highly geographically isolated areas. All of the studied populations (in Poland, Ukraine, and Slovakia) were differentiated at the mitochondrial marker COI. However, with respect to the nuclear marker ITS1, Polish populations were monomorphic, but distinct from all other populations. The distinctiveness of the studied populations was confirmed by Wolbachia screening, which showed that all populations carried different strains (one or two), which were probably transferred independently from other insects. On the other hand, no diversity was found in any marker within particular populations, which could be caused (at least for mtDNA) by a Wolbachia selective sweep. Crioceris quatuordecimpunctata probably consists of isolated populations, which went through narrow bottlenecks leading to a drastic reduction in their genetic diversity. As these populations are reciprocally monophyletic for mtDNA haplotypes and show a significant divergence of allele frequencies at nuclear loci, they could be classified as evolutionarily significant units (ESUs). In addition, DNA barcodes were used to identify Asparagus officinalis as the host plant for members of all studied populations. These data should be valuable in efforts to conserve populations of C. quatuordecimpunctata (e.g., for guiding reintroductions).
Migration of a retained surgical swab into the jejunum in a dog
Authors: Day J. L. , Pechman R. D. , Bahr R. J.
Published: October 2012

A two‐year‐old spayed female shih‐tzu was referred with a 10‐month history of lethargy, chronic diarrhoea and weight loss. On presentation, a partial response to antibiotics was noted. Physical examination revealed an abdominal mass, and serum biochemistry and haematology revealed a mature neutrophilia, hypoalbuminaemia and a non‐regenerative anaemia. Contrast radiography and abdominal ultrasound were suggestive of an intraluminal foreign body. Exploratory laparotomy revealed a surgical swab in the lumen of the jejunum that was associated with severe adhesions. Histopathology showed evidence of transmural migration of the swab from the peritoneal cavity to the lumen of the jejunum.
Rare Earth and High Field‐Strength Elements in the Multani Mitti Clay: A Study Using INAA
Authors: Waheed Shahida , Siddique Naila , Faiz Yasir
Published: October 2012

Instrumental neutron activation analysis was used to determine nine rare earth elements (REE), Sc and five high field‐strength elements (HFSE) in the Multani Mitti (MM) clay. Chondrite‐normalised rare earth element patterns for the MM clay compared with those for the Post‐Archaean Australian Shale (PAAS), Upper Continental Crust (UCC) and North American Shale Composite (NASC) showed enrichment of light REEs and depletion of heavy REEs with a slight negative Eu anomaly. The Multani Mitti clay showed close resemblance to PAAS and NASC in its average REE and HFSE contents. Positive correlations between La/Ce, La/Sm, La/Yb, Zr/Hf, Th/U and Th/Ta ratios predict enrichment of LREEs, Zr and Th and depletion of HREEs. A parent source of felsic origin for the MM clay is also endorsed through the high La/Th and low Th/Sc ratios observed.
Estimates of biological variation in routinely measured biochemical analytes in clinically healthy dogs
Authors: Ruaux Craig G. , Carney Patrick C. , Suchodolski Jan S. , Steiner Jörg M.
Published: October 2012

Background

The degree of biological variation in routinely measured concentrations and activities of biochemical analytes has not been well defined in client‐owned pet dogs.

Objectives

The aim of this study was to define indices of biological variation and, where appropriate, indices of individuality and critical change values for routinely measured serum biochemical analytes in a group of clinically healthy dogs owned and housed privately.

Methods

A prospective cohort study was conducted. Serum samples obtained from clinically healthy adult dogs at varying intervals over a 12‐week period were analyzed. For each sample, a panel of 14 analytes was measured. Three levels of outlier analyses were applied (analytical, intra‐individual, and inter‐individual), followed by nested ANOVA to calculate intra‐individual, inter‐individual, and analytical coefficients of variation (CVI, CVG, and CVA, respectively).

Results

Specimens from 11 dogs were analyzed. Individuality indices ranged from 0.9 for glucose and total triglyceride concentrations to 3.4 for ALT activity. Analytical variation (CVA) was > ½ CVI for 9/14 analytes, failing to meet criteria for acceptable analytical variation when defining critical change values. Where analyzer performance was acceptable, critical change values ranged from 26.4% for glucose concentration to 84.0% for total triglyceride concentration.

Conclusions

Many frequently measured analytes included in routine serum biochemical panels have high individuality. Thus, use of standard reference intervals to monitor changes over time in an individual is likely to miss meaningful biological change.
Theileriosis in a reindeer (Rangifer tarandus tarandus) associated with a potentially novel Theileria sp
Authors: Garner Bridget C. , Holman Patricia , Berent Linda M.
Published: October 2012

A 5‐year‐old male neutered reindeer (Rangifer tarandus tarandus) from Missouri was presented with a 3‐week history of anorexia, respiratory distress, lethargy, and weight loss. Blood smear review revealed that a small percentage of RBCs contained small (1–2 μm in length) pleomorphic piroplasms (signet ring, rod‐ or pear‐shaped, and elongate forms) with an eccentric magenta nucleus and basophilic cytoplasm. Nested PCR to specifically amplify a portion of the piroplasm small subunit ribosomal RNA (SSU rRNA) gene was performed on DNA extracted from an EDTA specimen of whole blood. Subsequent sequence analyses showed similarity between the reindeer hemoparasite and Theileria spp SSU rRNA gene sequences in the GenBank database, with highest similarity to those of a Theileria sp in a White‐tailed deer from North Texas (AY735132, AY735133). The reindeer and North Texas Theileria sp are genetically distinct from, albeit closely related to, the White‐tailed deer Theileria sp (subsequently referred to as T cervi). To the authors' knowledge, this is the first identification of Theileria of this genotype in a reindeer. Historically, T tarandirangiferis infection was found with associated mortality in reindeer in Russia, but reports predate molecular characterization. Hence, the relationship of T tarandirangiferis with either T cervi or this agent remains unknown. T cervi is not typically pathogenic in White‐tailed deer in the US unless the animal is immune‐compromised by stress or disease; however, mortality from T cervi infection in reindeer has been reported.
Level of Inquiry as Motivator in an Inquiry Methods Course for Preservice Elementary Teachers
Authors: Bulunuz Mizrap , Jarrett Olga S. , Martin‐Hansen Lisa
Published: October 2012

Of great importance for achieving science education reform may be teachers' interest in science and enjoyment of science. This study explores the motivational qualities (rated for interest, fun, and learning value) of different levels of inquiry of hands‐on class activities. The participants, 53 preservice teachers in two sections of a science methods course, rated the activities at the end of each class. At the end of the course, these activities were categorized by level of inquiry (levels 0–3), with 30% rated as level 0 (no inquiry), 40% as level 1, 22% as level 2, and 8% as level 3, according to how much choice was given for posing questions and designing investigations. Ratings of each hands‐on activity indicated that participants perceived activities of higher levels of inquiry to be more fun and more interesting. They also perceived that they had learned more. These findings suggest that course instructors should determine level of inquiry when planning course activities, and degree of participant input into course activities may be important in the development of interest in science. A focus on hands‐on learning especially at higher levels of inquiry may serve both to capture the interest of teachers and to model how they can make science more authentic and engaging for children.
Incorporating individual variability into mark–recapture models
Authors: Ford Jessica H. , Bravington Mark V. , Robbins Jooke
Published: October 2012

Understanding individual variation is a key challenge in ecology. Inherent individual differences in movement and behaviour pose fundamental problems in the analysis of mark–recapture data as unmodelled individual differences can bias estimates of population size and survival rates. Multi‐state mark–recapture models have been the focus of much recent research but have yet to explicitly incorporate individual variability.

We use a multi‐state mark–recapture model with individual‐level random effects, built in admb‐re, a software tool that automatically provides an accurate analytical approximation of the likelihood which is otherwise intractable. We tested the model using simulation studies and applied the model to data from North Atlantic humpback whales in the Stellwagen Bank National Marine Sanctuary where heterogeneity is apparent in both sighting probability and site preference.

Simulation studies demonstrated accurate estimation of true parameter values with random effects models but bias sometimes resulted from fitting simpler models.

In application to data from the North Atlantic humpback whales, we were able to estimate both annual variation in the local population and three measures of individual‐level variation. Results indicate considerable heterogeneity within this population in both sighting probability and site preference. Ignoring random effects led to bias in estimates of proportion of time within a marine reserve.
A penalized likelihood approach to pooling estimates of covariance components from analyses by parts
Authors: Meyer K.
Published: October 2012

Estimates of covariance matrices for numerous traits are commonly obtained by pooling results from a series of analyses of subsets of traits. A penalized maximum‐likelihood approach is proposed to combine estimates from part analyses while constraining the resulting overall matrices to be positive definite. In addition, this provides the scope for ‘improving’ estimates of individual matrices by applying a penalty to the likelihood aimed at borrowing strength from their phenotypic counterpart. A simulation study is presented showing that the new method performs well, yielding unpenalized estimates closer to results from multivariate analyses considering all traits, than various other techniques used. In particular, combining results for all sources of variation simultaneously minimizes deviations in phenotypic estimates if sampling covariances can be approximated. A mild penalty shrinking estimates of individual covariance matrices towards their sum or estimates of canonical eigenvalues towards their mean proved advantageous in most cases. The method proposed is flexible, computationally undemanding and provides combined estimates with good sampling properties and is thus recommended as alternative to current methods for pooling.
Transcriptional suppression of the neuronal PAS domain 4 (Npas4) gene by stress via the binding of agonist‐bound glucocorticoid receptor to its promoter
Authors: Furukawa‐Hibi Yoko , Yun Jaesuk , Nagai Taku , Yamada Kiyofumi
Published: October 2012

Neuronal PAS domain 4 (NPAS4), a brain‐specific helix–loop–helix transcription factor, has recently been shown to regulate the development of GABAergic inhibitory neurons. We previously reported that Npas4 mRNA expression levels were reduced in the hippocampus of mice exposed to social isolation or restraint stress, which was accompanied by impairment of memory, emotional behavior, and hippocampal neurogenesis. Therefore, the reduction of NPAS4 expression may play a role in stress‐induced brain dysfunction. In this study, to investigate the transcriptional regulation of Npas4 by stress, we focused on the effect of glucocorticoids (GCs) upon Npas4 transcription. Corticosterone treatment reduced Npas4 expression in the frontal cortex and hippocampus, whereas adrenalectomy caused an increase in expression. GC receptor (GR) antagonist, mifepristone, inhibited the stress‐induced reduction of Npas4 expression. Putative negative glucocorticoid response elements (GREs) were found −2000 to −1000 upstream of the Npas4 transcription initiation site. Npas4 promoter activity was increased by mifepristone or by mutation of the negative GRE sequences. A chromatin immunoprecipitation assay revealed that restraint stress increased the binding of GR to Npas4 promoter region in the hippocampus. These results suggest that transcription of Npas4 is down‐regulated by stress via the binding of agonist‐bound GR to its promoter.
Neuroprotective actions of Glucagon‐like peptide‐1 in differentiated human neuroprogenitor cells
Authors: Velmurugan Kalpana , Bouchard Ron , Mahaffey Gregory , Pugazhenthi Subbiah
Published: October 2012

Glucagon‐like peptide‐1 (GLP‐1)‐based therapies are currently available for the treatment of type 2 diabetes, based on their actions on pancreatic β cells. GLP‐1 is also known to exert neuroprotective actions. To determine its mechanism of action, we developed a neuron‐rich cell culture system by differentiating human neuroprogenitor cells in the presence of a combination of neurotrophins and retinoic acid. The neuronal nature of these cells was characterized by neurogenesis pathway‐specific array. GLP‐1 receptor expression was seen mainly in the neuronal population. Culture of neurons in the presence of Aβ oligomers resulted in the induction of apoptosis as shown by the activation of caspase‐3 and caspase‐6. Exendin‐4, a long‐acting analog of GLP‐1, protected the neurons from apoptosis induced by Aβ oligomers. Exendin‐4 stimulated cyclic AMP response element binding protein phosphorylation, a regulatory step in its activation. A transient transfection assay showed induction of a reporter linked to CRE site‐containing human brain‐derived neurotrophic factor promoter IV, by the growth factor through multiple signaling pathways. The anti‐apoptotic action of exendin‐4 was lost following down‐regulation of cAMP response element binding protein. Withdrawal of neurotrophins resulted in the loss of neuronal phenotype of differentiated neuroprogenitor cells, which was prevented by incubation in the presence of exendin‐4. Diabetes is a risk factor in the pathogenesis of Alzheimer's disease. Our findings suggest that GLP‐1‐based therapies can decrease the incidence of Alzheimer's disease among aging diabetic population.
Long‐term exogenous application of melatonin delays drought‐induced leaf senescence in apple
Authors: Wang Ping , Sun Xun , Li Chao , Wei Zhiwei , Liang Dong , Ma Fengwang
Published: October 2012

To examine the potential roles of melatonin in drought tolerance, we tested the effects of its long‐term exogenous application on ‘Hanfu’ apple (Malus domestica Borkh.). When 100 μm melatonin was added to soils under drought conditions, the resultant oxidative stress was eased and leaf senescence was delayed. This molecule significantly reduced chlorophyll degradation and suppressed the up‐regulation of senescence‐associated gene 12 (SAG12) and pheophorbide a oxygenase (PAO). Such treatment also alleviated the inhibition of photosynthesis brought on by drought stress. We also investigated quenching and the efficiency of Photosystem II (PSII) photochemistry under dark and light conditions and found that melatonin helped to maintain better function of PSII under drought. The addition of melatonin also controlled the burst of hydrogen peroxide, possibly through direct scavenging and by enhancing the activities of antioxidative enzymes and the capacity of the ascorbate–glutathione cycle. Thus, understanding this effect of melatonin on drought tolerance introduces new possibilities to use this compound for agricultural purposes.
Production and Characterization of the Intra‐ and Extracellular Carbohydrates and Polymeric Substances (EPS) of Three Sea‐Ice Diatom Species, and Evidence for a Cryoprotective Role for EPS
Authors: Aslam Shazia N. , Cresswell‐Maynard Tania , Thomas David N. , Underwood Graham J. C.
Published: October 2012

Diatoms and their associated extracellular polymeric substances (EPS) are major constituents of the microalgal assemblages present within sea ice. Yields and chemical composition of soluble and cell‐associated polysaccharides produced by three sea‐ice diatoms, Synedropsis sp., Fragilariopsis curta, and F. cylindrus, were compared. Colloidal carbohydrates (CC) contained heteropolysaccharides rich in mannose, xylose, galactose, and glucose. Synedropsis sp. CC consisted mainly of carbohydrates <8 kDa size, with relatively soluble EPS, compared to high proportions of less‐soluble EPS produced by both Fragilariopsis spp. F. curta colloidal EPS contained high concentrations of amino sugars (AS). Both Fragilariopsis species had high yields of hot bicarbonate (HB) soluble EPS, rich in xylose, mannose, galactose, and fucose (and AS in F. cylindrus). All species had frustule‐associated EPS rich in glucose–mannose. Nutrient limitation resulted in declines in EPS yields and in glucose content of all EPS fractions. Significant similarities between EPS fractions from cultures and different components of natural EPS from Antarctic sea ice were found. Increased salinity (52) reduced growth, but increased yields of EPS in Fragilariopsis cylindrus. Ice formation was inhibited byF. cylindrus, EPS, and by enhanced EPS content (additional xanthan gum) down to −12°C, with growth rate reduced in the presence of xanthan. Differences in the production and composition of EPS between Synedropsis sp. and Fragilariopsis spp., and the association between EPS, freezing and cell survival, supports the hypothesis that EPS production is a strategy to assist polar ice diatoms to survive the cold and saline conditions present in sea ice.
Oxygen Transport in the Microcirculation and Its Regulation
Authors: Pittman Roland N.
Published: October 2012

Objective

Cells require energy to carry out their functions and they typically use oxidative phosphorylation to generate the needed ATP. Thus, cells have a continuous need for oxygen, which they receive by diffusion from the blood through the interstitial fluid. The circulatory system pumps oxygen‐rich blood through a network of increasingly minute vessels, the microcirculation. The structure of the microcirculation is such that all cells have at least one nearby capillary for diffusive exchange of oxygen and red blood cells release the oxygen bound to hemoglobin as they traverse capillaries.

Methods

This review focuses first on the historical development of techniques to measure oxygen at various sites in the microcirculation, including the blood, interstitium, and cells.

Results

Next, approaches are described as to how these techniques have been employed to make discoveries about different aspects of oxygen transport. Finally, ways in which oxygen might participate in the regulation of blood flow toward matching oxygen supply to oxygen demand is discussed.

Conclusions

Overall, the transport of oxygen to the cells of the body is one of the most critical functions of the cardiovascular system and it is in the microcirculation where the final local determinants of oxygen supply, oxygen demand, and their regulation are decided.
Nuclear factor‐κB and p38 mitogen‐activated protein kinase signaling pathways are critically involved in Porphyromonas gingivalis lipopolysaccharide induction of lipopolysaccharide‐binding protein expression  in human oral keratinocytes
Authors: Ding P.‐H. , Wang C.‐Y. , Darveau R.P. , Jin L.J.
Published: October 2012

Lipopolysaccharide (LPS) ‐binding protein (LBP) plays a crucial role in innate host response to bacterial challenge. Porphyromonas gingivalis is a keystone pathogen in periodontal disease and the shift of P. gingivalis LPS lipid A structure from penta‐acylated (LPS1690) to tetra‐acylated (LPS1435/1449) isoform may significantly contribute to periodontal pathogenesis. We recently demonstrated that LBP is expressed in human gingiva and contributes to periodontal homeostasis. Furthermore, different isoforms of P. gingivalis LPS differently modulate the immuno‐inflammatory response, and P. gingivalis LPS1690 induces LBP expression in human oral keratinocytes (HOKs). This study further examined the signaling mechanisms of P. gingivalis LPS1690‐induced and Escherichia coli LPS‐induced LBP expression in HOKs. Both P. gingivalis LPS1690 and E. coli LPS were potent inducers of LBP expression in HOKs. The former activated phosphorylation of IκBα, p65, p38 mitogen‐activated protein kinase (MAPK) and stress‐activated protein kinase/c‐Jun N‐terminal kinase (SAPK/JNK), whereas the latter phosphorylated IκBα, p38 MAPK and SAPK/JNK. A nuclear translocation of NF‐κB transcription factor was confirmed upon stimulation by both forms of LPS. Further blocking assay showed that P. gingivalis LPS1690 induction of LBP was through NF‐κB and p38 MPAK pathways, whereas E. coli LPS‐induced LBP expression was mediated by NF‐κB, p38 MPAK and JNK pathways. This study demonstrates that NF‐κB and p38 MAPK signaling pathways are involved in P. gingivalis LPS1690 induction of LBP expression in HOKs. The current findings could enhance the understanding of the molecular mechanisms of innate defense in maintenance of periodontal homeostasis.
Genetic variation at KIT locus may predispose to melanoma
Authors: Bourillon Agnes , Hu Hui‐Han , Hetet Gilles , Lacapere Jean‐Jacques , André Jocelyne , Descamps Vincent , Basset‐Seguin Nicole , Ogbah Zighereda , Puig Susana , Saiag Philippe , Bagot Martine , Bensussan Armand , Grandchamp Bernard , Dumaz Nicolas , Soufir Nadem
Published: October 2012

As loss of KIT frequently occurs in melanoma progression, we hypothesized that KIT is implicated in predisposition to melanoma (MM). Thus, we sequenced the KIT coding region in 112 familial MM cases and 143 matched controls and genotyped tag single‐nucleotide polymorphisms (SNPs) in two cohorts of melanoma patients and matched controls. Five rare KIT substitutions, all predicted possibly or probably deleterious, were identified in five patients, but none in controls [RR = 2.26 (1.26–2.26)]. Expressed in melanocyte lines, three substitutions inhibited KIT signaling. Comparison with exomes database (7020 alleles) confirmed a significant excess of rare deleterious KIT substitutions in patients. Additionally, a common SNP, rs2237028, was associated with MM risk, and 6 KIT variants were associated with nevus count. Our data strongly suggest that rare KIT substitutions predispose to melanoma and that common variants at KIT locus may also impact nevus count and melanoma risk.
Gray Hausdorff distance measure for medical image comparison in dermatology: Evaluation of treatment effectiveness by image similarity
Authors: Spyridonos Panagiota , Gaitanis Georgios , Bassukas Ioannis D. , Tzaphlidou Margaret
Published: October 2012

Introduction

In clinical dermatology, the stabilization of the overall skin condition can be in many cases the earliest qualitative measure of the effectiveness of the therapeutic intervention. Subjective image comparisons, that offer empirical ‘qualitative’ judgments of degrees of image similarities, are traditionally employed by the involved physicians.

Objectives

To quantify, by means of an image similarity metric, the degree of stabilization of an expanding skin disease, and to identify the situation of ‘no further change’ of the skin condition of the patient, providing thus the physician with an early, objective measure of the efficacy of the used therapy.

Methods

For treatment assessment, a variant of gray Hausdorff distance metric was employed to compare images of lesional skin segments of a patient, taken at different time points during a therapeutic course. Prior to image comparison, an effective preprocessing scheme was adapted to constrain wide pose and light variations. The proposed similarity algorithm was tested on raw clinical image data sets of patients diagnosed with toxic epidermal necrolysis, a life‐threatening condition with rapid evolution. Fine tuning of algorithm's parameters was optimized using Precision‐Recall curves.

Results

Proposed image comparison method resulted in a high‐degree of image similarity (about 96%) between pictures taken at second and fifth day of hospitalization. Current similarity results substantiate a significant agreement between the computer‐treatment assessment, by means of image comparison, and the corresponding clinical experts’ review of skin condition.

Conclusion

Objective evidence of ‘no further change’ situation may provide (a) intuitive clinical decision support to dermatologists in assessing aggressive skin conditions, where the timely evaluation of treatment response is of vital importance and (b) a versatile end‐point measure for corresponding therapeutic clinical trials.
Apical myosin XI anticipates F‐actin during polarized growth of Physcomitrella patens cells
Authors: Furt Fabienne , Liu Yen‐Chun , Bibeau Jeffrey P. , Tüzel Erkan , Vidali Luis
Published: October 2012

Tip growth is essential for land colonization by bryophytes, plant sexual reproduction and water and nutrient uptake. Because this specialized form of polarized cell growth requires both a dynamic actin cytoskeleton and active secretion, it has been proposed that the F‐actin‐associated motor myosin XI is essential for this process. Nevertheless, a spatial and temporal relationship between myosin XI and F‐actin during tip growth is not known in any plant cell. Here, we use the highly polarized cells of the moss Physcomitrella patens to show that myosin XI and F‐actin localize, in vivo, at the same apical domain and that both signals fluctuate. Surprisingly, phase analysis shows that increase in myosin XI anticipates that of F‐actin; in contrast, myosin XI levels at the tip fluctuate in identical phase with a vesicle marker. Pharmacological analysis using a low concentration of the actin polymerization inhibitor latrunculin B showed that the F‐actin at the tip can be significantly diminished while myosin XI remains elevated in this region, suggesting that a mechanism exists to cluster myosin XI‐associated structures at the cell's apex. In addition, this approach uncovered a mechanism for actin polymerization‐dependent motility in the moss cytoplasm, where myosin XI‐associated structures seem to anticipate and organize the actin polymerization machinery. From our results, we inferred a model where the interaction between myosin XI‐associated vesicular structures and F‐actin polymerization‐driven motility function at the cell's apex to maintain polarized cell growth. We hypothesize this is a general mechanism for the participation of myosin XI and F‐actin in tip growing cells.
Mixed Convection Falkner–Skan Flow of a Maxwell Fluid
Authors: Hayat T. , Farooq M. , Iqbal Z. , Alsaedi A.
Published: October 2012

We performed a study for the effect of Newtonian heating on the nonsimilar mixed convection Falkner–Skan flow of a Maxwell fluid. Transformation procedure is adopted in obtaining the ordinary differential equations. Homotopic approach is adopted for the series solutions of velocity and temperature. Special emphasis is given to the effects of Prandtl number (Pr) and conjugate parameter (γ) which measure the strength of surface heating. It is observed that temperature and heat transfer rate are enhanced by increasing the conjugate parameter.
Nanotechnology Applications in Orthopedic Surgery
Authors: Brenner Sara A. , Ling John F.
Published: October 2012

Nanotechnology applications in medicine are poised to revolutionize the prevention, diagnosis, and treatment of disease. Researchers, scientists, and physicians across various disciplines and specialties are working to develop innovative clinical tools that incorporate materials, devices, and systems engineered at the nanoscale. Surgical specialties, such as orthopedic surgery, are among those developing nanotechnology applications for clinical use. Orthopedic surgery addresses disorders of the musculoskeletal system including repair by both surgical and nonsurgical means of tendons, ligaments, muscles, bones, and nerves injured due to trauma or disease. Medical interventions targeting orthopedic conditions are becoming increasingly important given current epidemiologic trends in these conditions. The purpose of this article is to highlight current and emerging applications of nanotechnology in orthopedic surgery. Selected, clinically relevant examples are described in the categories of drugs and drug delivery, imaging, sensors, biomaterials, diagnostics, and novel therapeutics. Several promising nanomedicine applications that target orthopedic conditions are in various stages of development from basic scientific research to clinical trials to product development and commercialization. Nanotechnology applications aimed at the prevention, diagnosis, and treatment of orthopedic conditions hold great promise for improving the standard of care in orthopedic surgery in the 21st century.