bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of ‘Student‐to‐Student Local Analgesia Administration’ on undergraduate students' opinions regarding ‘Pain‐Free Local Analgesia Technique’ in children
Authors: Kuscu O. O. , Kucuktepe C. , Caglar E. , Cildir S. K. , Hacinlioglu N. , Sandallı N.
Published: March 2013

Aim

To examine the role of ‘student‐to‐student local analgesia administration’ on undergraduate dental students' opinions regarding pain‐free local analgesia techniques in children.

Methods

Grade 3 (n:29), Grade 4 (n:59) and Grade 5 students (n:28) of Yeditepe University, School of Dentistry, Istanbul, Turkey participated in the study. Informed consent and ethical approval were obtained. Students' opinions were evaluated by means of a short survey administered before and after educational activities. Activities were provided in a didactic manner (theoretical, practical and clinical stages) and lasted for 6 months. Theoretical lectures on ‘pain‐free local analgesia techniques in children’ were given to all classes. In the practical stage, 3rd and 4th grade students were paired and performed infiltration analgesia on each other according to the lectured technique. In the final clinical stage, 4th and 5th grade students were supervised, whilst administering the technique on children during their clinical training.

Results

Before the activities, only 40% of students believed in the possibility of pain‐free local analgesia in children, whereas after the educational activities, the percentage had risen to 68% (P = 0.0001). A significant difference was observed between the opinions of 4th grade students who attended the practical stage and 5th grade students who did not.

Conclusion

The role of ‘student‐to‐student local analgesia administration’ was found to be significant in changing undergraduate students' opinions about pain‐free dental injections in children.
Development of cortical influences on superior colliculus multisensory neurons: effects of dark‐rearing
Authors: Yu Liping , Xu Jinghong , Rowland Benjamin A. , Stein Barry E.
Published: March 2013

Rearing cats from birth to adulthood in darkness prevents neurons in the superior colliculus (SC) from developing the capability to integrate visual and non‐visual (e.g. visual‐auditory) inputs. Presumably, this developmental anomaly is due to a lack of experience with the combination of those cues, which is essential to form associative links between them. The visual‐auditory multisensory integration capacity of SC neurons has also been shown to depend on the functional integrity of converging visual and auditory inputs from the ipsilateral association cortex. Disrupting these cortico‐collicular projections at any stage of life results in a pattern of outcomes similar to those found after dark‐rearing; SC neurons respond to stimuli in both sensory modalities, but cannot integrate the information they provide. Thus, it is possible that dark‐rearing compromises the development of these descending tecto‐petal connections and the essential influences they convey. However, the results of the present experiments, using cortical deactivation to assess the presence of cortico‐collicular influences, demonstrate that dark‐rearing does not prevent the association cortex from developing robust influences over SC multisensory responses. In fact, dark‐rearing may increase their potency over that observed in normally‐reared animals. Nevertheless, their influences are still insufficient to support SC multisensory integration. It appears that cross‐modal experience shapes the cortical influence to selectively enhance responses to cross‐modal stimulus combinations that are likely to be derived from the same event. In the absence of this experience, the cortex develops an indiscriminate excitatory influence over its multisensory SC target neurons.
Effect of pretreatment with calcium‐containing desensitizer on the dentine bonding of mild self‐etch adhesives
Authors: Pei Dandan , Liu Siying , Huang Cui , Du Xijin , Yang Hongye , Wang Yake , Deng Donglai
Published: March 2013

Desensitizing agents are frequently applied to sensitive teeth and may affect subsequent resin bonding. The current study aimed to evaluate the bonding performance of two self‐etch adhesives containing functional monomers to dentine pretreated with three new calcium‐containing desensitizers. No desensitizer was applied in the control group. Groups 1, 2, and 3 were treated with an arginine–calcium carbonate‐containing polishing paste, a casein phosphopeptide–amorphous calcium phosphate (CPP‐ACP)‐containing paste, and an experimental hydroxyapatite paste, respectively. G‐Bond and Clearfil S3 Bond were used for bonding after desensitizer treatments. The microtensile bond strength (μTBS) was tested (n = 20 beams per group) and failure mode distribution was analyzed. Scanning electron microscopy was used to observe the occlusion of dentinal tubules. The mean (±SD) μTBS values, expressed in MPa, of groups 1, 2, and 3 and the control group were, respectively, 30.81 (7.79), 44.41 (8.02), 31.49 (6.13), and 41.40 (8.67) for G‐Bond and 39.63 (9.59), 32.55 (7.86), 37.50 (8.60), 27.90 (6.52) for S3 Bond. Most failures were recorded as adhesive failure (69.375%), instead of cohesive failure or mixed failure. The dentinal tubules were seldom plugged in group 2, but were mostly occluded in groups 1 and 3. Two‐way anova indicated that desensitizer application in association with a compatible adhesive system should be used when endeavoring to control hypersensitivity without adverse interference in bonding.
A phylomedicine approach to understanding the evolution of auditory sensory perception and disease in mammals
Authors: Kirwan John D. , Bekaert Michaël , Commins Jennifer M. , Davies Kalina T. J. , Rossiter Stephen J. , Teeling Emma C.
Published: March 2013

Hereditary deafness affects 0.1% of individuals globally and is considered as one of the most debilitating diseases of man. Despite recent advances, the molecular basis of normal auditory function is not fully understood and little is known about the contribution of single‐nucleotide variations to the disease. Using cross‐species comparisons of 11 ‘deafness’ genes (Myo15, Ush1 g, Strc, Tecta, Tectb, Otog, Col11a2, Gjb2, Cldn14, Kcnq4, Pou3f4) across 69 evolutionary and ecologically divergent mammals, we elucidated whether there was evidence for: (i) adaptive evolution acting on these genes across mammals with similar hearing capabilities; and, (ii) regions of long‐term evolutionary conservation within which we predict disease‐associated mutations should occur. We find evidence of adaptive evolution acting on the eutherian mammals in Myo15, Otog and Tecta. Examination of selection pressures in Tecta and Pou3f4 across a taxonomic sample that included a wide representation of auditory specialists, the bats, did not uncover any evidence for a role in echolocation. We generated ‘conservation indices’ based on selection estimates at nucleotide sites and found that known disease mutations fall within sites of high evolutionary conservation. We suggest that methods such as this, derived from estimates of evolutionary conservation using phylogenetically divergent taxa, will help to differentiate between deleterious and benign mutations.
Single and repeated sevoflurane or desflurane exposure does not impair spatial memory performance of young adult mice
Authors: Kilicaslan Alper , Belviranli Muaz , Okudan Nilsel , Nurullahoglu Atalik Esra
Published: March 2013

Volatile anesthetics are known to disturb the spatial memory in aged rodents, but there is insufficient information on their effects on young adult rodents. The aim of this study was to compare the effects of single and repeated exposure to desflurane and sevoflurane on spatial learning and memory functions in young adult mice. Balb/c mice (2 months old) were randomly divided into six equal groups (n = 8). The groups with single inhalation were exposed to 3.3% sevoflurane or 7.8% desflurane or vehicle gas for 4 h, respectively. The groups with repeated inhalation were exposed to 3.3% sevoflurane or 7.8% desflurane or vehicle gas for 2 h a day during 5 consecutive days. Spatial learning and memory were tested in the Morris water maze 24 h after exposure. In the learning phase, the parameters associated with finding the hidden platform and swimming speed, and in the memory phase, time spent in the target quadrant and the adjacent quadrants, were assessed and compared between the groups. In the 4‐day learning process, there was no significant difference between the groups in terms of mean latency to platform, mean distance traveled and average speed (P > 0.05). During the memory‐test phase, all mice exhibited spatial memory, but there was no significant difference between the groups in terms of time spent in the target quadrant (P > 0.05). Sevoflurane and desflurane anesthesia did not impair acquisition learning and retention memory in young adult mice.
Evaluation of the fluorescent probes Nile Red and 25‐NBD‐cholesterol as substrates for steroid‐converting oxidoreductases using pure enzymes and microorganisms
Authors: Faletrov Yaroslav V. , Frolova Nina S. , Hlushko Hanna V. , Rudaya Elena V. , Edimecheva Irina P. , Mauersberger Stephan , Shkumatov Vladimir M.
Published: March 2013

The fluorescent probes Nile Red (nonsteroidal dye) and 25‐{N‐[(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl)‐methyl]amino}‐27‐norcholesterol (25‐NBD‐cholesterol) (a cholesterol analog) were evaluated as novel substrates for steroid‐converting oxidoreductases. Docking simulations with autodock showed that Nile Red fits well into the substrate‐binding site of cytochrome P450 17α‐hydroxylase/17,20‐lyase (CYP17A1) (binding energy value of −8.3 kcal·mol−1). Recombinant Saccharomyces cerevisiae and Yarrowia lipolytica, both expressing CYP17A1, were found to catalyze the conversion of Nile Red into two N‐dealkylated derivatives. The conversion by the yeasts was shown to increase in the cases of coexpression of electron‐donating partners of CYP17A1. The highest specific activity value (1.30 ± 0.02 min−1) was achieved for the strain Y. lipolytica DC5, expressing CYP17A1 and the yeast's NADPH‐cytochrome P450 reductase. The dye was also metabolized by pure CYP17A1 into the N‐dealkylated derivatives, and gave a type I difference spectrum when titrated into low‐spin CYP17A1. Analogously, docking simulations demonstrated that 25‐NBD‐cholesterol binds into the active site of the microbial cholesterol oxidase (CHOX) from Brevibacterium sterolicum (binding energy value of −5.6 kcal·mol−1). The steroid was found to be converted into its 4‐en‐3‐one derivative by CHOX (Km and kcat values were estimated to be 58.1 ± 5.9 μm and 0.66 ± 0.14 s−1, respectively). The 4‐en‐3‐one derivative was also detected as the product of 25‐NBD‐cholesterol oxidation with both pure microbial cholesterol dehydrogenase (CHDH) and a pathogenic bacterium, Pseudomonas aeruginosa, possessing CHOXs and CHDHs. These results provide novel opportunities for investigation of the structure–function relationships of the aforementioned oxidoreductases, which catalyze essential steps of steroid bioconversion in mammals (CYP17A1) and bacteria (CHOX and CHDH), with fluorescence‐based techniques.
A Descriptive and Co‐Constructive Approach to Integrated Performance Assessment Feedback
Authors: Adair‐Hauck Bonnie , Troyan Francis J.
Published: March 2013

This article presents a descriptive and Co‐Constructive Approach to feedback related to performance in the interpersonal mode of communication on the Integrated Performance Assessment (IPA). The goal of this research study was to describe the discursive features of effective IPA feedback. To this end, critical discourse analysis of a feedback session between a teacher and one student is presented and discussed. Based on this analysis, the discourse features of feedback that encourage self‐reflection and self‐regulation are extrapolated. Characteristics for effective feedback are presented to serve as guidelines for teachers implementing the IPA in their classrooms.
The Determinants of Sticky Prices and Sticky Plans: Evidence from German Business Survey Data
Authors: Schenkelberg Heike
Published: March 2013

So far, there is no consensus on the price adjustment determinants in the empirical literature. Analyzing a novel firm-level business survey data set, we provide new insights on the price setting behavior of German retailers during a low inflation period. Relating the probability of both price and pricing plan adjustment to time- and state-dependent variables, we find that state-dependence is important; the macroeconomic environment as well as the firm-specific condition significantly determines the timing of both actual price changes and pricing plan adjustments. Moreover, input cost changes are important determinants of price setting. Finally, price increases respond more strongly to cost shocks compared to price decreases.
Variations in circulating sex steroid levels in metastatic prostate cancer patients with combined androgen blockade: observation and implication
Authors: Qin X. , Zhang H. , Ye D. , Yao X. , Zhang S. , Dai B.
Published: March 2013

Testosterone is the major precursor of estradiol (E2) in men. We hypothesized that, in metastatic prostate cancer, androgen deprivation therapy suppression of serum androgen to the castration level may also disrupt serum E2 level, and variation in serum E2 level might play a role in the development of castration‐resistant prostate cancer. Our investigation was designed to observe the variation in circulating oestrogen and androgen levels in metastatic prostate cancer patients after combined androgen blockade, and to explore the possible clinical significance. We recruited 105 consecutive metastatic prostate cancer patients who were treated with combined androgen blockade from June to August 2011, and divided them into three groups according to different hormone‐sensitivity status, including 58 hormone‐sensitive prostate cancers, 27 after failure of first‐line hormone therapy (androgen‐independent prostate cancer) and 20 castration‐resistant prostate cancers. Another 36 consecutive patients with treatment‐naive metastatic prostate cancer during the same period were used as controls. Serum testosterone, E2 and E2/testosterone (E2/T) ratio were analysed and compared between the groups. After combined androgen blockade, testosterone was suppressed to a low level, regardless of different hormone sensitivity (p > 0.05). Mean serum testosterone was 4.07, 0.15, 0.11 and 0.09 ng/mL in treatment‐naive, hormone‐sensitive, androgen‐independent and castration‐resistant prostate cancer respectively. For each group, mean E2 was 33.06, 9.23, 9.13 and 15.05 pg/mL respectively. Mean E2/T was 9.58, 269.29, 292.06 and 996.67 respectively. Recovery of E2 and increased E2/T ratio were more significantly associated with combined androgen blockade failure, especially in castration‐resistant prostate cancer (p < 0.001). This study indicated that metabolism of oestrogen might change during combined androgen blockade in metastatic prostate cancer patients, and oestrogen‐related pathways might play a role in the development of castration‐resistant prostate cancer.
Environmental Factors Predict the Severity of Delirium Symptoms in Long‐Term Care Residents with and without Delirium
Authors: McCusker Jane , Cole Martin G. , Voyer Philippe , Vu Minh , Ciampi Antonio , Monette Johanne , Champoux Nathalie , Belzile Eric , Dyachenko Alina
Published: March 2013

Objectives

To identify potentially modifiable environmental factors (including number of medications) associated with changes over time in the severity of delirium symptoms and to explore the interactions between these factors and resident baseline vulnerability.

Design

Prospective, observational cohort study.

Setting

Seven long‐term care (LTC) facilities.

Participants

Two hundred seventy‐two LTC residents aged 65 and older with and without delirium.

Measurements

Weekly assessments (for up to 6 months) of the severity of delirium symptoms using the Delirium Index (DI), environmental risk factors, and number of medications. Baseline vulnerability measures included a diagnosis of dementia and a delirium risk score. Associations between environmental factors, medications, and weekly changes in DI were analyzed using a general linear model with correlated errors.

Results

Six potentially modifiable environmental factors predicted weekly changes in DI (absence of reading glasses, aids to orientation, family member, and glass of water and presence of bed rails and other restraints) as did the prescription of two or more new medications. Residents with dementia appeared to be more sensitive to the effects of these factors.

Conclusion

Six environmental factors and prescription of two or more new medications predicted changes in the severity of delirium symptoms. These risk factors are potentially modifiable through improved LTC clinical practices.
Evidence on the Benefits of Alternative Mortgage Products
Authors: COCCO JOÃO F.
Published: March 2013

Alternative mortgage products have been identified by many as culprits in the financial crisis. However, because of their lower initial mortgage payments relative to loan amount, they may be a valuable tool for households that expect higher and more certain future labor income, and that wish to smooth consumption over the life‐cycle. Using U.K. household‐level panel data, this paper provides evidence in support of this hypothesis and highlights other important benefits of alternative mortgages, including portfolio diversification, tax benefits, and a reduction in the transaction costs incurred in housing transactions.
Competitive effect and response of savanna tree seedlings: comparison of survival, growth and associated functional traits
Authors: Pillay Tiffany , Ward David
Published: March 2013

Questions

What is the effect of neighbour competition on the survival, growth and biomass of mesic and humid savanna tree species? Can competitive effect and response be linked to plant functional traits?

Location

Neil Tainton Arboretum, University of KwaZulu‐Natal, Pietermaritzburg, ZA.

Methods

Using a target–neighbour design, all combinations of four humid and four mesic savanna tree seedlings were tested in a greenhouse experiment, to establish the effects of neighbourhood competition on target plant performance. The competitive response and effect of each species was quantified, and regressed against several functional traits to determine which traits are predictive of competitive ability.

Results

We found that neighbour density negatively affected the survival of mesic tree seedlings but not humid tree seedlings. Mesic plants were able to maintain their relative growth rates (RGRs) despite increasing neighbourhood competition. The RGRs of humid species significantly decreased as the density of neighbours increased, indicating that competition may be a factor affecting plants in savannas receiving more than 650 mm mean annual rainfall. We used the quantile regression method to show that the biomass of humid tree seedlings decreased with increased neighbour biomass, when considering competitive response only. We also found that resource‐acquiring traits (such as maximum RGR, plant height and root biomass) were positively correlated with the competitive effect of mesic savanna seedlings, while specific leaf area captured the competitive response of humid savanna seedlings to neighbour competition.

Conclusions

Competitive interactions between savanna trees negatively affect survival and growth rate, although the competitive effect or response of a particular species depends on its adaptation to either high‐ or low‐resource environments. Our results show significant relationships between plant traits and competitive ability, which may be used to predict competitive interactions between tree seedlings from humid and mesic savannas.
Bite force and encephalization in theCanidae (Mammalia:Carnivora)
Authors: Damasceno E. M. , Hingst‐Zaher E. , Astúa D.
Published: March 2013

The ways in which the taxonomic differences in morphology, behavior or life history relate to each other have been used regularly to test ideas about the selective forces involved in their evolution. Canid species vary significantly in diet, hunting techniques, sociality and cranial morphology. The main goal of this study is to test and explore the possible correlation between bite force and brain volume in canids. For that, we calculated the bite force based on the beam theory, and the brain volume based on three cranial measurements. The species with biggest values of bite force quotient (BFQ) wereSpeothos venaticus(162.25),Cuon alpinus(129.24) andLycaon pictus(124.41) due to several adaptations acquired along with hypercarnivory. Species with the highest values of brain volume quotient (BVQ) wereS. venaticus,Cu. alpinusandL. pictuswith, respectively, 141.35, 139.01 and 131.61, possibly due to the same adaptations that resulted in their biggerBFQ. The highest values of bite force belonged toCanis lupus(830.51 Pa),L. pictus(719.03 Pa) andCa. rufus(530.52 Pa) and the smallest values belong toUrocyon littoralis(98.14 Pa),Vulpes macrotis(92.53 Pa) andV. zerda(72.6 Pa).Ca. lupus,L. pictusandChrysocyon brachyuruspossess the largest brain volumes with respectively 159.29, 146.94 and 120.84 mm3and the smallest values belong toNyctereutes procyonoides(28.2 mm3),V. rueppelli(27.86 mm3) andV. zerda(20.65 mm3). The independent contrasts correlation showed that there is no correlation betweenBVQandBFQ(r = 0.14/P= 0.46), as well as no correlation betweenBFQandBF(r = 0.22/P= 0.26), which indicates the efficiency of the size correction. Bite force and brain volume estimates are much higher in the group hunting hypercarnivores (Lycaon,CuonandSpeothos) and only these showed correlation betweenBFQandBVQ. Our results indicate that cranial adaptations for hypercarnivory also influence braincase size.
LiverAtlas: a unique integrated knowledge database for systems‐level research of liver and hepatic disease
Authors: Zhang Yanqiong , Yang Chunyuan , Wang Shaochuang , Chen Tao , Li Mansheng , Wang Xue , Li Dongsheng , Wang Kang , Ma Jie , Wu Songfeng , Zhang Xueli , Zhu Yunping , Wu Jinsheng , He Fuchu
Published: March 2013

Background

A large amount of liver‐related physiological and pathological data exist in publicly available biological and bibliographic databases, which are usually far from comprehensive or integrated. Data collection, integration and mining processes pose a great challenge to scientific researchers and clinicians interested in the liver.

Method

To address these problems, we constructed LiverAtlas (http://liveratlas.hupo.org.cn), a comprehensive resource of biomedical knowledge related to the liver and various hepatic diseases by incorporating 53 databases.

Results

In the present version, LiverAtlas covers data on liver‐related genomics, transcriptomics, proteomics, metabolomics and hepatic diseases. Additionally, LiverAtlas provides a wealth of manually curated information, relevant literature citations and cross‐references to other databases. Importantly, an expert‐confirmed Human Liver Disease Ontology, including relevant information for 227 types of hepatic disease, has been constructed and is used to annotate LiverAtlas data. Furthermore, we have demonstrated two examples of applying LiverAtlas data to identify candidate markers for hepatocellular carcinoma (HCC) at the systems level and to develop a systems biology‐based classifier by combining the differential gene expression with topological features of human protein interaction networks to enhance the ability of HCC differential diagnosis.

Conclusion

LiverAtlas is the most comprehensive liver and hepatic disease resource, which helps biologists and clinicians to analyse their data at the systems level and will contribute much to the biomarker discovery and diagnostic performance enhancement for liver diseases.
Heme deficiency of soluble guanylate cyclase induces gastroparesis
Authors: Cosyns S. M. R. , Dhaese I. , Thoonen R. , Buys E. S. , Vral A. , Brouckaert P. , Lefebvre R. A.
Published: March 2013

Background

Soluble guanylate cyclase (sGC) is the principal target of nitric oxide (NO) to control gastrointestinal motility. The consequence on nitrergic signaling and gut motility of inducing a heme‐free status of sGC, as induced by oxidative stress, was investigated.

Methods

sGCβ1H105F knock‐in (apo‐sGC) mice, which express heme‐free sGC that has basal activity, but cannot be stimulated by NO, were generated.

Key Results

Diethylenetriamine NONOate did not increase sGC activity in gastrointestinal tissue of apo‐sGC mice. Exogenous NO did not induce relaxation in fundic, jejunal and colonic strips, and pyloric rings of apo‐sGC mice. The stomach was enlarged in apo‐sGC mice with hypertrophy of the muscularis externa of the fundus and pylorus. In addition, gastric emptying and intestinal transit were delayed and whole‐gut transit time was increased in the apo‐sGC mice, while distal colonic transit time was maintained. The nitrergic relaxant responses to electrical field stimulation at 1–4 Hz were abolished in fundic and jejunal strips from apo‐sGC mice, but in pyloric rings and colonic strips, only the response at 1 Hz was abolished, indicating the contribution of other transmitters than NO.

Conclusions & Inferences

The results indicate that the gastrointestinal consequences of switching from a native sGC to a heme‐free sGC, which cannot be stimulated by NO, are most pronounced at the level of the stomach establishing a pivotal role of the activation of sGC by NO in normal gastric functioning. In addition, delayed intestinal transit was observed, indicating that nitrergic activation of sGC also plays a role in the lower gastrointestinal tract.
Association genetics of oleoresin flow in loblolly pine: discovering genes and predicting phenotype for improved resistance to bark beetles and bioenergy potential
Authors: Westbrook Jared W. , Resende Marcio F. R. , Munoz Patricio , Walker Alejandro R. , Wegrzyn Jill L. , Nelson C. Dana , Neale David B. , Kirst Matias , Huber Dudley A. , Gezan Salvador A. , Peter Gary F. , Davis John M.
Published: March 2013

Rapidly enhancing oleoresin production in conifer stems through genomic selection and genetic engineering may increase resistance to bark beetles and terpenoid yield for liquid biofuels.

We integrated association genetic and genomic prediction analyses of oleoresin flow (g 24 h−1) using 4854 single nucleotide polymorphisms (SNPs) in expressed genes within a pedigreed population of loblolly pine (Pinus taeda) that was clonally replicated at three sites in thesoutheasternUnitedStates.

Additive genetic variation in oleoresin flow (h2≈ 0.12–0.30) was strongly correlated between years in which precipitation varied (ra≈ 0.95), while the genetic correlation between sites declined from 0.8 to 0.37 with increasing differences in soil and climate among sites. A total of 231SNPs were significantly associated with oleoresin flow, of which 81% were specific to individual sites.SNPs in sequences similar to ethylene signaling proteins,ABCtransporters, and diterpenoid hydroxylases were associated with oleoresin flow across sites.

Despite this complex genetic architecture, we developed a genomic prediction model to accelerate breeding for enhanced oleoresin flow that is robust to environmental variation. Results imply that breeding could increase oleoresin flow 1.5‐ to 2.4‐fold in one generation.
Control of T cell tolerance by phosphatase and tensin homolog
Authors: Huynh Alexandria , Turka Laurence A.
Published: March 2013

The in vivo maintenance of immune tolerance is critically dependent on regulatory T (Treg) cells, a lineage of CD4+ T cells expressing the transcription factor Foxp3 that exerts immunoregulatory function. Because of the potential benefit of using Treg cells for cellular immunotherapy in clinical settings, including autoimmune disease and transplantation, much attention has been directed at understanding the signals that govern Treg cell development, function, and homeostasis. Studies with genetically modified mouse models have shown that the lipid phosphatase PTEN (phosphatase and tensin homolog), the predominant negative regulator of the PI3K/Akt pathway in T cells, has multiple functions in sustaining T cell–mediated immune tolerance in vivo. In addition to its role in maintaining T cell homeostasis, the PI3K/Akt pathway also has an essential role in T cell development and lineage commitment, contributing to the cell fate decision between conventional and regulatory T cells.
Role of SHIP1 in cancer and mucosal inflammation
Authors: Fernandes Sandra , Iyer Sonia , Kerr William G.
Published: March 2013

The SH‐2 containing inositol 5′‐polyphosphatase 1 (SHIP1) is a multifunctional protein expressed predominantly, but not exclusively, by hematopoietic cells. SHIP1 removes the 5′‐phosphate from the product of PI3K, PI(3,4,5)P3, to generate PI(3,4)P2. Both PIP species influence the activity level of Akt and ultimately regulate cell survival and differentiation. SHIP1 also harbors several protein interaction domains that endow it with many nonenzymatic cell signaling or receptor masking functions. In this review, we discuss the opposing roles of SHIP1 in cancer and in mucosal inflammation. On one hand, germline loss of SHIP1 causes myeloid lung consolidation and severe inflammation in the ileum, a phenotype that closely mimics human Crohn's disease and can be rescued by reconstitution with SHIP1‐competent T cells. On the other, transient inhibition of the enzymatic activity of SHIP1 in cancer cells leads to apoptosis and enhances survival in lethal murine xenograft models. Overall, careful dissection of the different pathological mechanisms involved in several diseases provides novel opportunities for therapeutic intervention targeting SHIP1.
Durum wheat varieties in N‐deficient environments and organic farming: a comparison of yield, quality and stability performances
Authors: Stagnari Fabio , Onofri Andrea , Codianni Pasquale , Pisante Michele
Published: March 2013

Stability and reliability of yield and quality for 15 durum wheat genotypes (old and modern) were evaluated in a 5‐year experiment (southern Italy) in organic farming. Genotypes were grown at two N levels (0 and 80 kg/ha), with the aim of evaluating ‘genotype × environment’ (GE) interactions and their role on genotype selection in N‐limited environments. Several approaches to stability were used, within the frame of mixed models and additive main effects and multiplicative interaction analysis, and their validity in stressful conditions and organic farming was discussed. Especially for protein and gluten content, results indicate high environmental variability and the presence of crossover ‘N × environment’ interactions, which supports the need for specific breeding programmes in N‐deficient environments. The average response was strongly affected by N availability (on average, yield was 2.95 and 3.42 t/ha, protein content was 11.6% and 12.85%, gluten content was 8.55% and 9.92%, respectively, at 0 and 80 kg N/ha), and few genotypes gave high yield and quality at both fertilization levels. Only ‘Gargano’ and ‘Fortore’ showed a good inter‐year stability at both N levels. The old cultivars gave minimal responsiveness to increased N input, but gave good results in limiting conditions, indicating that they may play a role in organic farming.
Diagnostic Value of the Skin Lesions in Immune Dysregulation, Polyendocrinopathy, Enteropathy, X‐Linked Syndrome
Authors: Martín‐Santiago Ana , Hervás Juan A. , Hervás Daniel , Rosell Antonio , Caimari María , de Carlos Juan C. , Matamoros Nuria
Published: March 2013

We report a child with immune dysregulation, polyendocrinopathy, enteropathy, X‐linked (IPEX) syndrome due to a de novo c.1190G>A (p.R397Q) mutation in exon 11 of the forkhead domain of the FOXP3 gene. He had chronic dermatitis with an eczematous and ichthyosiform appearance and had an allogeneic bone marrow transplantation. IPEX syndrome is a rare, often fatal recessive disease caused by mutations in the FOXP3 gene on the X chromosome (Xp11.23‐q13.3).
Congenital Myxoid and Pigmented Dermatofibrosarcoma Protuberans: A Case Report
Authors: Hachem May El , Diociaiuti Andrea , Latella Ermenegilda , Zama Mario , Lambiase Caterina , Giraldi Loredana , Surrenti Tiziana , Callea Francesco
Published: March 2013

Dermatofibrosarcoma protuberans (DFSP) is a low‐grade, mesenchymal, spindle cell tumor. In addition to the classical form characterized by a storiform pattern of tumor cells, pigmented (Bednar's tumor) and myxoid variants can be observed. Classical DFSP and Bednar's tumor are easily diagnosed. The myxoid variant represents a diagnostic challenge. Pigmented and myxoid variants are rare and thus far have never been reported in association in congenital DFSP. We came across a unique DFSP that was, at the same time, congenital, pigmented, and myxoid. The tumor was surgically excised with broad free margins and no recurrence. The differential diagnosis with other entities such as giant cell fibroblastoma, CD34‐positive plaque‐like dermal fibroma, superficial plaque‐like CD34 DFSP, and neurocristic hamartoma is discussed. The recognition of this hybrid variant of congenital DFSP is important to avoid under‐ or overtreatment.
Modeling Poliovirus Risks and the Legacy of Polio Eradication
Authors: Thompson Kimberly M.
Published: March 2013

This introduction to the special issue on modeling poliovirus risks provides context about historical efforts to manage polioviruses and reviews the insights from models developed to support risk management and policy development. Following an overview of the contents of the special issue, the introduction explores the road ahead and offers perspective on the legacy of polio eradication.
Evaluating Methods for Estimating Existential Risks
Authors: Tonn Bruce , Stiefel Dorian
Published: March 2013

Researchers and commissions contend that the risk of human extinction is high, but none of these estimates have been based upon a rigorous methodology suitable for estimating existential risks. This article evaluates several methods that could be used to estimate the probability of human extinction. Traditional methods evaluated include: simple elicitation; whole evidence Bayesian; evidential reasoning using imprecise probabilities; and Bayesian networks. Three innovative methods are also considered: influence modeling based on environmental scans; simple elicitation using extinction scenarios as anchors; and computationally intensive possible‐worlds modeling. Evaluation criteria include: level of effort required by the probability assessors; level of effort needed to implement the method; ability of each method to model the human extinction event; ability to incorporate scientific estimates of contributory events; transparency of the inputs and outputs; acceptability to the academic community (e.g., with respect to intellectual soundness, familiarity, verisimilitude); credibility and utility of the outputs of the method to the policy community; difficulty of communicating the method's processes and outputs to nonexperts; and accuracy in other contexts. The article concludes by recommending that researchers assess the risks of human extinction by combining these methods.
Identification of a novel HLA‐A*33:03:11 allele by polymerase chain reaction sequence‐based typing in a Chinese cord blood donor
Authors: Zhang W. , Tao S.‐D. , Zhu F.‐M. , He J. , Lv H.‐J.
Published: March 2013

HLA‐A*33:03:11 differs from A*33:03:01 by one nucleotide substitution in exon 3 at position 531 G>A.
The Inhibitor of wax 1 locus (Iw1) prevents formation of β‐ and OH‐β‐diketones in wheat cuticular waxes and maps to a sub‐cM interval on chromosome arm 2BS
Authors: Adamski Nikolai M. , Bush Maxwell S. , Simmonds James , Turner Adrian S. , Mugford Sarah G. , Jones Alan , Findlay Kim , Pedentchouk Nikolai , von Wettstein‐Knowles Penny , Uauy Cristobal
Published: March 2013

Glaucousness is described as the scattering effect of visible light from wax deposited on the cuticle of plant aerial organs. In wheat, two dominant genes lead to non‐glaucous phenotypes: Inhibitor of wax 1 (Iw1) and Iw2. The molecular mechanisms and the exact extent (beyond visual assessment) by which these genes affect the composition and quantity of cuticular wax is unclear. To describe the Iw1 locus we used a genetic approach with detailed biochemical characterization of wax compounds. Using synteny and a large number of F2 gametes, Iw1 was fine‐mapped to a sub‐cM genetic interval on wheat chromosome arm 2BS, which includes a single collinear gene from the corresponding Brachypodium and rice physical maps. The major components of flag leaf and peduncle cuticular waxes included primary alcohols, β‐diketones and n‐alkanes. Small amounts of C19–C27 alkyl and methylalkylresorcinols that have not previously been described in wheat waxes were identified. Using six pairs of BC2F3 near‐isogenic lines, we show that Iw1 inhibits the formation of β‐ and hydroxy‐β‐diketones in the peduncle and flag leaf blade cuticles. This inhibitory effect is independent of genetic background or tissue, and is accompanied by minor but consistent increases in n‐alkanes and C24 primary alcohols. No differences were found in cuticle thickness and carbon isotope discrimination in near‐isogenic lines differing at Iw1.
Two-Phase Liquid Cooling for Thermal Management of IGBT Power Electronic Module
Authors: Wang Peng , McCluskey Patrick , Bar-Cohen Avram
Published: March 2013

Recent trends including rapid increases in the power ratings and continued miniaturization of semiconductor devices have pushed the heat dissipation of power electronics well beyond the range of conventional thermal management solutions, making control of device temperature a critical issue in the thermal packaging of power electronics. Although evaporative cooling is capable of removing very high heat fluxes, two-phase cold plates have received little attention for cooling power electronics modules. In this work, device-level analytical modeling and system-level thermal simulation are used to examine and compare single-phase and two-phase cold plates for a specified inverter module, consisting of 12 pairs of silicon insulated gate bipolar transistor (IGBT) devices and diodes. For the conditions studied, an R134a-cooled, two-phase cold plate is found to substantially reduce the maximum IGBT temperature and spatial temperature variation, as well as reduce the pumping power and flow rate, in comparison to a conventional single-phase water-cooled cold plate. These results suggest that two-phase cold plates can be used to substantially improve the performance, reliability, and conversion efficiency of power electronics systems.
Study on Heat Conduction in a Simulated Multicore Processor Chip—Part I: Analytical Modeling
Authors: Nakayama Wataru
Published: March 2013

A system of temperature calculations is developed to study the conditions leading to hot spot occurrence on multicore processor chips. The analysis is performed on a physical model which incorporates certain salient features of multicore processor. The model has active and background cells laid out in a checkered pattern, and the pattern repeats itself in fine grain active cells. The die has a buried dioxide and a wiring layer stacked on the die body, and heat sources are placed at the wiring layer/buried oxide interface. With this model we explore the effects of various parameters on the target spot temperature. The parameters are the die dimensions, the materials' thermal conductivities, the effective heat transfer coefficients on the die surfaces, the power map, and the spatial resolution with which we view the power and temperature distributions on the die. Closed-form analytical solutions are derived and used to examine the roles of these parameters in creating hot spots. The present paper reports the details of mathematical formulations and steps of temperature calculation. The results for a particular example case are included to illustrate what can be learned from the calculations.
Study on Heat Conduction in a Simulated Multicore Processor Chip—Part II: Case Studies
Authors: Nakayama Wataru
Published: March 2013

The objective of this study is to understand the effects of various parameters involved in the chip design and cooling on the occurrence of hot spots on a multicore processor chip. The thermal environment for the die is determined by the cooling design which differs distinctly between different classes of electronic equipment. In the present study, like many other hot spot studies, the effective heat transfer coefficient represents the thermal environment for the die, but, its representative values are derived for different cooling schemes in order to examine in what classes of electronic equipment the hot spot concern grows. The cooling modes under study are high-performance air-cooling, high-performance liquid-cooling, conventional air-cooling, and oil-cooling in infrared radiation (IR) thermography setup. Temperature calculations were performed on a model which is designed to facilitate the study of several questions that have not been fully addressed in the existing literature. These questions are concerned with the granularity of power and temperature distributions, thermal interactions between circuits on the die, the roles of on-chip wiring layer and the buried dioxide in heat spreading, and the mechanism of producing temperature contrast across the die. The main results of calculations are the temperature of the target spot and the temperature contrast across the die. Temperature contrasts are predicted in a range 10–25 K, and the results indicate that a major part of the temperature contrast is formed at a granularity corresponding to the size of functional units on actual microprocessor chips. At a fine granularity level and under a scenario of high power concentration, the on-chip wiring layer and the buried oxide play some roles in heat spreading, but their impact on the temperature is generally small. However, the details of circuits need to be taken into account in future studies in order to investigate the possibility of nanometer-scale hot spots. Attention is also called to the need to understand the effect of temperature nonuniformity on the processor performance for which low temperature at inactive cells makes a major contribution. In contrast to the situation for the die under forced convection cooling, the die in passively cooled compact equipment is in distinctly different thermal environment. Strong thermal coupling between the die and the system structure necessitates the integration of package and system level analysis with the die-level analysis.
Application of Distance Geometry to Tracing Coupler Curves of Pin-Jointed Linkages1
Authors: Rojas Nicolás , Thomas Federico
Published: March 2013

In general, high-order coupler curves of single-degree-of-freedom plane linkages cannot be properly traced by standard predictor–corrector algorithms due to drifting problems and the presence of singularities. Instead of focusing on finding better algorithms for tracing curves, a simple method that first traces the configuration space of planar linkages in a distance space and then maps it onto the mechanism workspace, to obtained the desired coupler curves, is proposed. Tracing the configuration space of a linkage in the proposed distance space is simple because the equation that implicitly defines this space can be straightforwardly obtained from a sequence of bilaterations, and the configuration space embedded in this distance space naturally decomposes into components corresponding to different combinations of signs for the oriented areas of the triangles involved in the bilaterations. The advantages of this two-step method are exemplified by tracing the coupler curves of a double butterfly linkage.
Comparative Study of Thermal Performance of Longitudinal and Transversal-Wavy Microchannel Heat Sinks for Electronic Cooling
Authors: Xie Gongnan , Liu Jian , Liu Yanquan , Sunden Bengt , Zhang Weihong
Published: March 2013

Liquid cooling incorporating microchannels are used to cool electronic chips in order to remove more heat load. However, such microchannels are often designed to be straight with rectangular cross section. In this paper, on the basis of straight microchannels having rectangular cross section (SRC), longitudinal-wavy microchannel (LWC), and transversal microchannel (TWC) were designed, respectively, and then the corresponding laminar flow and heat transfer were investigated numerically. Among them, the channel wall of LWC undulates along the flow direction according to a sinusoidal function while the TWC undulates along the transversal direction. The numerical results show that for removing an identical heat load, the overall thermal resistance of the LWC is decreased with increasing inlet Reynolds number while the pressure drop is increased greatly, so that the overall thermal performance of LWC is inferior to that of SRC under the considered geometries. On the contrary, TWC has a great potential to reduce the pressure drop compared to SRC, especially for higher wave amplitudes at the same Reynolds number. Thus the overall thermal performance of TWC is superior to that of SRC. It is suggested that the TWC can be used to cool chips effectively with much smaller pressure drop penalty. In addition to the overall thermal resistance, other criteria of evaluation of the overall thermal performance, e.g., (Nu/Nu0)/(f/f0) and (Nu/Nu0)/(f/f0)1/3, are applied and some controversial results are obtained.
Positional Error Estimation in Serial Link Manipulator Under Joint Clearances and Backlash
Authors: Jawale H. P. , Thorat H. T.
Published: March 2013

The serial link manipulators are most commonly used for industrial applications. The positional accuracy is an important specification for performance evaluation of a serial chain manipulator. The factors influencing the positional accuracy of serial link robotic manipulator includes joint clearances, and drive backlash. This paper presents method for evaluating the effect of joint error on positional accuracy of the robotic manipulator. Serial chain Two Revolute Joint (2R) planar manipulator is modeled to position the end effector in workspace. The inverse kinematic analysis under ideal joint provides the link properties for respective end effector location. Formulation for manipulator link properties under influence of the joint clearance is presented. Effect of drive backlash on positional accuracy of end effector is analyzed. Positional deviations at end effector positions over workspace are estimated. Maximum error under influence of backlash and clearances is estimated at all possible end effector positions.
The Biological Underpinnings of Namib Desert Fairy Circles
Authors: Juergens Norbert
Published: March 2013

Fairies? No, Termites!

Fairy circles consist of circles of perennial vegetation that grow within otherwise mostly barren desert habitat on the southwest coast of Africa. Many hypotheses have been put forward to explain the creation and maintenance of fairy circles. Using long-term data collected on the distribution and physical and biological components of these features,
Juergens
(p.
1618
) found that the circles are generated by the actions of the sand termite, which removes vegetation produced following intermittent rains. Once generated, the circles collect water, which sustains the growth of perennial vegetation at the edges of the circles, allowing for long-term persistence of the termites.
Epigenetic Reprogramming in Cancer
Authors: Suvà Mario L. , Riggi Nicolo , Bernstein Bradley E.
Published: March 2013

The demonstration of induced pluripotency and direct lineage conversion has led to remarkable insights regarding the roles of transcription factors and chromatin regulators in mediating cell state transitions. Beyond its considerable implications for regenerative medicine, this body of work is highly relevant to multiple stages of oncogenesis, from the initial cellular transformation to the hierarchical organization of established malignancies. Here, we review conceptual parallels between the respective biological phenomena, highlighting important interrelationships among transcription factors, chromatin regulators, and preexisting epigenetic states. The shared mechanisms provide insights into oncogenic transformation, tumor heterogeneity, and cancer stem cell models.