bluuebunny/crossref_metadata_2025 huggingface dataset:
p57kip2 regulates glial fate decision in adult neural stem cells
Authors: Jadasz Janusz J. , Rivera Francisco J. , Taubert Agnes , Kandasamy Mahesh , Sandner Beatrice , Weidner Norbert , Aktas Orhan , Hartung Hans-Peter , Aigner Ludwig , Küry Patrick
Published: August 2012

Our recent studies revealed p57kip2 as an intrinsic regulator of late gliogenesis and demonstrated that in oligodendroglial precursor cells p57kip2 inhibition leads to accelerated maturation. Adult neural stem cells have been described as a source of glial progenitors; however, the underlying mechanisms of cell fate specification are still poorly understood. Here, we have investigated whether p57kip2 can influence early events of glial determination and differentiation. We found that Sox2/GFAP double-positive cells express p57kip2 in stem cell niches of the adult brain. Short-hairpin RNA-mediated suppression of p57kip2 in cultured adult neural stem cells was found to strongly reduce astroglial characteristics, while oligodendroglial precursor features were increased. Importantly, this anti-astrogenic effect of p57kip2 suppression dominated the bone morphogenetic protein-mediated promotion of astroglial differentiation. Moreover, we observed that in p57kip2 knockdown cells, the BMP antagonist chordin was induced. Finally, when p57kip2-suppressed stem cells were transplanted into the adult spinal cord, fewer GFAP-positive cells were generated and oligodendroglial markers were induced when compared with control cells, demonstrating an effect of in vivo relevance.
DrosophilaCORL is required for Smad2-mediated activation of Ecdysone Receptor expression in the mushroom body
Authors: Takaesu Norma T. , Stinchfield Michael J. , Shimizu Kazumichi , Arase Mayu , Quijano Janine C. , Watabe Tetsuro , Miyazono Kohei , Newfeld Stuart J.
Published: August 2012

CORL proteins (FUSSEL/SKOR proteins in humans) are related to Sno/Ski oncogenes but their developmental roles are unknown. We have cloned Drosophila CORL and show that its expression is restricted to distinct subsets of cells in the central nervous system. We generated a deletion of CORL and noted that homozygous individuals rarely survive to adulthood. Df(4)dCORL adult escapers display mushroom body (MB) defects and Df(4)dCORL larvae are lacking Ecdysone Receptor (EcR-B1) expression in MB neurons. This is phenocopied in CORL-RNAi and Smad2-RNAi clones in wild-type larvae. Furthermore, constitutively active Baboon (type I receptor upstream of Smad2) cannot stimulate EcR-B1 MB expression in Df(4)dCORL larvae, which demonstrates a formal requirement for CORL in Smad2 signaling. Studies of mouse Corl1 (Skor1) revealed that it binds specifically to Smad3. Overall, the data suggest that CORL facilitates Smad2 activity upstream of EcR-B1 in the MB. The conservation of neural expression and strong sequence homology of all CORL proteins suggests that this is a new family of Smad co-factors.
Formation and specification of a Drosophila dopaminergic precursor cell
Authors: Watson Joseph D. , Crews Stephen T.
Published: August 2012

Dopaminergic neurons play important roles in animal behavior, including motivation, reward and locomotion. The Drosophila dopaminergic H-cell interneuron is an attractive system for studying the genetics of neural development because analysis is focused on a single neuronal cell type. Here we provide a mechanistic understanding of how MP3, the precursor to the H-cell, forms and acquires its identity. We show that the gooseberry/gooseberry-neuro (gsb/gsb-n) transcription factor genes act to specify MP3 cell fate. It is proposed that single-minded commits neuroectodermal cells to a midline fate, followed by a series of signaling events that result in the formation of a single gsb+/gsb-n+ MP3 cell per segment. The wingless signaling pathway establishes a midline anterior domain by activating expression of the forkhead transcription factors sloppy paired 1 and sloppy paired 2. This is followed by hedgehog signaling that activates gsb/gsb-n expression in a subgroup of anterior cells. Finally, Notch signaling results in the selection of a single MP3, with the remaining cells becoming midline glia. In MP3, gsb/gsb-n direct H-cell development, in large part by activating expression of the lethal of scute and tailup H-cell regulatory genes. Thus, a series of signaling and transcriptional events result in the specification of a unique dopaminergic precursor cell. Additional genetic experiments indicate that the molecular mechanisms that govern MP3/H-cell development might also direct the development of non-midline dopaminergic neurons.
BMP-dependent serosa and amnion specification in the scuttle fly Megaselia abdita
Authors: Rafiqi Ab. Matteen , Park Chee-Hyurng , Kwan Chun Wai , Lemke Steffen , Schmidt-Ott Urs
Published: August 2012

Bone morphogenetic protein (BMP) signaling is an essential factor in dorsoventral patterning of animal embryos but how BMP signaling evolved with fundamental changes in dorsoventral tissue differentiation is unclear. Flies experienced an evolutionary reduction of extra-embryonic tissue types from two (amniotic and serosal tissue) to one (amnionserosal tissue). BMP-dependent amnioserosa specification has been studied in Drosophila melanogaster. However, the mechanisms of serosal and amniotic tissue specification in less diverged flies remain unknown. To better understand potential evolutionary links between BMP signaling and extra-embryonic tissue specification, we examined the activity profile and function of BMP signaling in serosa and amnion patterning of the scuttle fly Megaselia abdita (Phoridae) and compared the BMP activity profiles between M. abdita and D. melanogaster. In blastoderm embryos of both species, BMP activity peaked at the dorsal midline. However, at the beginning of gastrulation, peak BMP activity in M. abdita shifted towards prospective amnion tissue. This transition correlated with the first signs of amnion differentiation laterally adjacent to the serosa anlage. Marker-assisted analysis of six BMP signaling components (dpp, gbb, scw, tkv, sax, sog) by RNA interference revealed that both serosa and amnion specification of M. abdita are dependent on BMP activity. Conversely, BMP gain-of-function experiments caused sharpened expression boundaries of extra-embryonic target genes indicative of positive feedback. We propose that changes in the BMP activity profile at the beginning of gastrulation might have contributed to the reduction of extra-embryonic tissue types during the radiation of cyclorrhaphan flies.
Fasting hyperglycemia in the Goto-Kakizaki rat is dependent on corticosterone: a confounding variable in rodent models of type 2 diabetes
Authors: Beddow Sara A. , Samuel Varman T.
Published: August 2012

The Goto-Kakizaki (GK) rat is an inbred model of type 2 diabetes (T2D); GK rats are lean but have hyperglycemia and increased gluconeogenesis. However, fasting hyperglycemia in other commonly used rodent models of T2D is associated with increased corticosterone, and thus the underlying mechanism for hyperglycemia differs significantly from T2D in humans. Information regarding corticosterone in the GK rat is not readily available. We studied 14- to 16-week-old GK rats in comparison with age-matched control Wistar-Kyoto (WK) rats. GK rats had lower body weights (WK: 343±10 g vs GK: 286±9 g, P<0.01), but higher plasma glucose concentrations (WK: 132±1.5 mg/dl vs GK: 210±11.7 mg/dl, P<0.01). This was associated with an ~twofold increase in PEPCK1 expression (P<0.05). However, these findings were also associated with elevations in plasma corticosterone and urinary corticosterone excretion. Ketoconazole (KTZ) treatment in GK rats reduced plasma corticosterone, fasting glucose (GK: 218±15 mg/dl vs GK-KTZ: 135±19 mg/dl, P<0.01) and rates of glucose production (GK: 16.5±0.6 mg/(kg-minute) vs GK-KTZ: 12.2±0.9 mg/(kg-minute), P<0.01). This was associated with an ~40% reduction in hepatic PEPCK1 expression as well as a 20% reduction in alanine turnover. Thus, hypercorticosteronemia might contribute to the diabetic phenotype of GK rats and should be considered as a potential confounder in rodent models of T2D.
Mutation of sec63 in zebrafish causes defects in myelinated axons and liver pathology
Authors: Monk Kelly R. , Voas Matthew G. , Franzini-Armstrong Clara , Hakkinen Ian S. , Talbot William S.
Published: August 2012

Mutations in SEC63 cause polycystic liver disease in humans. Sec63 is a member of the endoplasmic reticulum (ER) translocon machinery, although it is unclear how mutations in SEC63 lead to liver cyst formation in humans. Here, we report the identification and characterization of a zebrafish sec63 mutant, which was discovered in a screen for mutations that affect the development of myelinated axons. Accordingly, we show that disruption of sec63 in zebrafish leads to abnormalities in myelinating glia in both the central and peripheral nervous systems. In the vertebrate nervous system, segments of myelin are separated by the nodes of Ranvier, which are unmyelinated regions of axonal membrane containing a high density of voltage-gated sodium channels. We show that sec63 mutants have morphologically abnormal and reduced numbers of clusters of voltage-gated sodium channels in the spinal cord and along peripheral nerves. Additionally, we observe reduced myelination in both the central and peripheral nervous systems, as well as swollen ER in myelinating glia. Markers of ER stress are upregulated in sec63 mutants. Finally, we show that sec63 mutants develop liver pathology. As in glia, the primary defect, detectable at 5 dpf, is fragmentation and swelling of the ER, indicative of accumulation of proteins in the lumen. At 8 dpf, ER swelling is severe, other pathological features include disrupted bile canaliculi, altered cytoplasmic matrix, and accumulation of large lysosomes. Together, our analyses of sec63 mutant zebrafish highlight the possible role of ER stress in polycystic liver disease and suggest that these mutants will serve as a model for understanding the pathophysiology of this disease and other abnormalities involving ER stress.
A mathematical model of weight loss under total starvation: evidence against the thrifty-gene hypothesis
Authors: Speakman John R. , Westerterp Klaas R.
Published: August 2012

The thrifty-gene hypothesis (TGH) posits that the modern genetic predisposition to obesity stems from a historical past where famine selected for genes that promote efficient fat deposition. It has been previously argued that such a scenario is unfeasible because under such strong selection any gene favouring fat deposition would rapidly move to fixation. Hence, we should all be predisposed to obesity: which we are not. The genetic architecture of obesity that has been revealed by genome-wide association studies (GWAS), however, calls into question such an argument. Obesity is caused by mutations in many hundreds (maybe thousands) of genes, each with a very minor, independent and additive impact. Selection on such genes would probably be very weak because the individual advantages they would confer would be very small. Hence, the genetic architecture of the epidemic may indeed be compatible with, and hence support, the TGH. To evaluate whether this is correct, it is necessary to know the likely effects of the identified GWAS alleles on survival during starvation. This would allow definition of their advantage in famine conditions, and hence the likely selection pressure for such alleles to have spread over the time course of human evolution. We constructed a mathematical model of weight loss under total starvation using the established principles of energy balance. Using the model, we found that fatter individuals would indeed survive longer and, at a given body weight, females would survive longer than males, when totally starved. An allele causing deposition of an extra 80 g of fat would result in an extension of life under total starvation by about 1.1-1.6% in an individual with 10 kg of fat and by 0.25-0.27% in an individual carrying 32 kg of fat. A mutation causing a per allele effect of 0.25% would become completely fixed in a population with an effective size of 5 million individuals in 6000 selection events. Because there have probably been about 24,000 famine events since the evolution of hominins 4 million years ago, there has been ample time even for genes with only very minor impacts on adiposity to move to fixation. The observed polymorphic variation in the genes causing the predisposition to obesity is incompatible with the TGH, unless all these single nucleotide polymorphisms (SNPs) arose in the last 900,000 years, a requirement we know is incorrect. The TGH is further weakened by the observation of no link between the effect size of these SNPs and their prevalence, which would be anticipated under the TGH model of selection if all the SNPs had arisen in the last 900,000 years.
Cognitive effects of dopamine depletion in the context of diminished acetylcholine signaling capacity in mice
Authors: Zurkovsky Lilia , Bychkov Evgeny , Tsakem Elviche L. , Siedlecki Carley , Blakely Randy D. , Gurevich Eugenia V.
Published: August 2012

A subset of patients with Parkinson's disease acquires a debilitating dementia characterized by severe cognitive impairments (i.e. Parkinson's disease dementia; PDD). Brains from PDD patients show extensive cholinergic loss as well as dopamine (DA) depletion. We used a mutant mouse model to directly test whether combined cholinergic and DA depletion leads to a cognitive profile resembling PDD. Mice carrying heterozygous deletion of the high-affinity, hemicholinium-3-sensitive choline transporter (CHTHET) show reduced levels of acetylcholine throughout the brain. We achieved bilateral DA depletion in CHTHET and wild-type (WT) littermates via intra-striatal infusion of 6-hydroxydopamine (6-OHDA), or used vehicle as control. Executive function and memory were evaluated using rodent versions of cognitive tasks commonly used with human subjects: the set-shifting task and spatial and novel-object recognition paradigms. Our studies revealed impaired acquisition of attentional set in the set-shifting paradigm in WT-6OHDA and CHTHET-vehicle mice that was exacerbated in the CHTHET-6OHDA mice. The object recognition test following a 24-hour delay was also impaired in CHTHET-6OHDA mice compared with all other groups. Treatment with acetylcholinesterase (AChE) inhibitors physostigmine (0.05 or 0.1 mg/kg) and donepezil (0.1 and 0.3 mg/kg) reversed the impaired object recognition of the CHTHET-6OHDA mice. Our data demonstrate an exacerbated cognitive phenotype with dual ACh and DA depletion as compared with either insult alone, with traits analogous to those observed in PDD patients. The results suggest that combined loss of DA and ACh could be sufficient for pathogenesis of specific cognitive deficits in PDD.
Role of chymase in diabetic nephropathy
Authors: Cristovam Priscila C , Carmona Adriana K , Arnoni Carine P , Maquigussa Edgar , Pereira Luciana G , Boim Mirian A
Published: August 2012

Chymase is an alternative pathway for angiotensin-converting enzyme in angiotensin II (Ang II) formation, and its expression is increased in human diabetic kidneys and in human mesangial cells (MCs) stimulated with high glucose. In addition, chymase activates transforming growth factor (TGF- β1) via an Ang II-independent pathway. The aim of this study was to evaluate the role of chymase on TGF- β1 activation in diabetic rats and in rat MCs (RMCs) stimulated with high glucose (HG). Diabetes was induced in male Wistar rats by streptozotocin (60 mg/kg, intravenous). After 30 (D30) or 60 (D60) days, chymase activity and the expression of profibrotic markers were evaluated. RMCs were stimulated with HG in the presence or absence of 50 μmol/L chymostatin, a chymase inhibitor, or 100 nmol/L of losartan, an Ang II antagonist. Chymase activity and expression increased in D60 kidneys, with increased expression of fibronectin, type I and III collagen, TGF- β1 and Smad 3 and with no change in Smad 7 expression. RMCs exposed to HG presented increases in chymase activity and expression, together with upregulation in fibrosis markers and in the TGF- β1 signaling pathway. All these effects were reversed by chymostatin and by losartan, but type 1 angiotensin II receptor blockade did not interfere with the Smad 3 and 7 pathway. Similar to HG-stimulated RMCs, control RMCs treated with chymase responded with increased expression of TGF- β1, Smad 3 and fibrosis markers. These effects were reversed by chymostatin but not by losartan. The results indicate an important role for chymase in inducing fibrosis through TGF- β1 activation, parallel with Ang II effects.
Prenatal and early postnatal exposure to high-saturated-fat diet represses Wnt signaling and myogenic genes in offspring rats
Authors: Yang Ke-Feng , Shen Xiu-Hua , Cai Wei
Published: August 2012

The prenatal and early postnatal period is a key developmental window for nutrition status, and high-fat exposure in this period has been shown to be associated with type 2 diabetes, obesity and other features of metabolic disorders later in life. The present study was designed to investigate the underlying molecular mechanisms and role of relative genes involved in this process. We investigated the impact of prenatal and early postnatal exposure to a high-saturated-fat diet on the regulation of the Wnt signaling pathway and myogenic genes in skeletal muscle of rat offspring as well as the serum and muscle physiological outcomes. Timed-pregnant Sprague-Dawley rats were fed either a control (C, 16% kcal fat) or high-saturated-fat diet (HF, 45% kcal fat) throughout gestation and lactation. After weaning, female offspring were fed a control diet to generate two offspring groups: control diet-fed offspring of control diet-fed dams (C/C) and control diet-fed offspring of HF diet-fed dams (HF/C). The serum glucose of the HF/C offspring (5.58 ± 0.26 mmol/L) was significantly higher than that of C/C offspring (4.97 ± 0.28 mmol/L), and the Homeostasis Model Assessment-Insulin Resistance of HF/C offspring (2.00 ± 0.11) was also significantly higher when compared with C/C (1.84 ± 0.09). Furthermore, HF/C offspring presented excessive intramuscular fat accumulation (1.8-fold, P < 0.05) and decreased muscle glycogen (1.3-fold, P < 0.05), as well as impairment of muscle development at the age of 12 weeks. Meanwhile, we observed the repression of Wnt/ β-catenin signaling and myogenic genes in HF/C offspring. The present study indicates that prenatal and early postnatal exposure to a high-saturated-fat diet suppresses the development of skeletal muscle and myogenic genes via Wnt/ β-catenin signaling, and the inappropriate muscle development could potentially contribute to the predisposition of offspring to develop metabolic-syndrome-like phenotype in adulthood.
Resveratrol promotes neurotrophic factor release from astroglia
Authors: Zhang Feng , Lu Yuan-Fu , Wu Qin , Liu Jie , Shi Jing-Shan
Published: August 2012

Neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) are considered to contribute to the development, maintenance and survival of neurons, glia and oligodendrocytes. Astroglia are a major source of various neurotrophic factors. Thus, enhancement of astroglia-mediated neurotrophic factor release might hold promising potential for neurological diseases. Resveratrol, a natural non-flavonoid polyphenol found in grapes and red wine, has been recognized to be beneficial for health. Here, rat primary astroglia-enriched cultures were used to investigate the effects of resveratrol-mediated neurotrophic factor release and the related mechanisms. The cultures were treated with 25–100 μmmol/L resveratrol for 12–48 h. Results showed resveratrol increased BDNF and GDNF production in the culture medium. In addition, the production of BDNF in the supernatant of cultures was increased five-fold over control cultures 24 h after resveratrol treatment and then remained high 36 h later. Meanwhile, the production of GDNF was initially increased by up to four-fold 24 h after resveratrol treatment and continued to increase to six-fold at 36 h and remained at a high level till 48 h. Western blot analysis of BDNF and GDNF protein in astroglia at different time points after resveratrol treatment indicated similar increases. Furthermore, resveratrol significantly induced the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and cAMP responsive element-binding protein (CREB) in astroglia. Overall, resveratrol is effective in promoting astroglia-derived neurotrophic factor release, and this effect is mediated, at least in part, by the activation of ERK1/2 and CREB.
Medical forensic examination of detained immigrants: is the Istanbul Protocol followed?
Authors: Keten Alper , Akçan Ramazan , Karacaoğlu Emre , Odabaşı Aysun Balseven , Rıza Tümer Ali
Published: August 2012

Introduction

Maltreatment and torture during custody is still an important problem in many countries. Both national and international regulations and the Istanbul Protocol are of great importance in terms of elimination of maltreatment and torture. In this study, we evaluated whether examinations for custody of immigrants were performed in accordance with the Istanbul Protocol.

Method

We retrospectively evaluated reports of forensic examinations for custody of 100 immigrants in Van-çaldıran Government Hospital in 2009. Data about nationality, age, gender, examination date, referring department, examination findings and departments to which the reports were submitted were collected.

Results

Fifty percent of the immigrants were Iranian and they were aged between 11 and 62 years. Ninety-nine immigrants were men and one was woman. Data about history of arrest were missing in forensic reports about all immigrants. Data about signs of trauma were present only for seven immigrants. Ninety-three immigrants were reported to have no signs of trauma. None of the immigrants underwent psychiatric examination. All forensic reports were found to be submitted to the police personally. Whether the immigrants were examined before or after the custody was not clear in the reports.

Conclusion

Evaluation of the data showed that none of the forensic examinations were performed in accordance with the Istanbul Protocol. It can be recommended that the protocol should be incorporated into the curricula for undergraduate, graduate and in-service training programmes in order to improve relevant forensic practices.
Unusual localization of a primary superficial venous aneurysm: a case report
Authors: Cakia M , Ersoy O , Ince I , Kiziltepe U
Published: August 2012

Objectives

Primary aneurysms of superficial venous system are rare and frequently misdiagnosed as varicose veins. Clinical presentation is variable depending on the presence of compression to surrounding structures. We report a rare case of primary cephalic vein aneurysm presented with wrist pain due to radial nerve compression.

Method/case

A 61-year-old woman was admitted with right wrist pain and localized mass. Physical and imaging examinations showed a localized cephalic vein aneurysm compressing radial nerve. Simple excision was performed successfully.

Results

Cosmetic and clinical results at the first month follow-up were successful.

Discussion

Although primary superficial venous aneurysms of upper extremities are very rare, the treatment of choice is most commonly same as the ones in lower limbs. Simple excision is the best approach in the most of the cases, while sclerotherapy could be preferred in order to obtain better cosmesis or to avoid injuries to surrounding structures.
Conditionalization of Copula-Based Models
Authors: Kurowicka Dorota
Published: August 2012

Copula models are becoming increasingly popular in engineering and financial applications. They provide a flexible way of constructing joint distributions with arbitrary one-dimensional margins and a wide variety of dependence structures. This paper studies different types of conditionalization of copula-based models. We conditionalize these models in the usual way on point values but also propose a different type of conditionalization on a new margin. This new type of conditionalization is motivated by experience with a model built for application in modeling risk in civil aviation. Changing one margin in a copula model is very easy; however, it is not equivalent to conditionalizing on a new margin. For this purpose, the technique presented by Holland and Wang [Holland PW, Wang YJ (1987) Dependence function for continuous bivariate densities. Commun. Statist. Theory Methods 16(3):867–876], called marginal replacement, is used. The main result of this paper allows a simplified way of conditionalizing on more than one univariate margin in a normal copula model.
Multiple-Unit Holdings Yield Attenuated Endowment Effects
Authors: Burson Katherine , Faro David , Rottenstreich Yuval
Published: August 2012

Previous endowment effect experiments have examined circumstances in which people encounter a single unit of a good (e.g., one chocolate). We contrast single-unit treatments with multiple-unit treatments in which participants encounter several units of a good (e.g., five chocolates). We observe endowment effects of typical magnitude for singleton holdings but attenuated endowment effects for multiple-unit holdings. Moreover, endowment effects consistently arise for singletons even as the definition of a unit is altered. For instance, participants holding one piece of chocolate show an endowment effect of standard size, but so do participants holding one box of chocolates. Yet the box contains about 20 individual pieces of chocolate, and participants given that many separate pieces show a substantially attenuated endowment effect. We thus propose the property of “unit dependence”: the definition of a unit can change, but contingent on any given definition, a pronounced endowment effect may emerge for singletons but not multiples.

This paper was accepted by Teck Ho, decision analysis.
Performance-Based Contracts for Outpatient Medical Services
Authors: Jiang Houyuan , Pang Zhan , Savin Sergei
Published: August 2012

In recent years, the performance-based approach to contracting for medical services has been gaining popularity across different healthcare delivery systems, both in the United States (under the name of “pay for performance”) and abroad (“payment by results” in the United Kingdom). The goal of our research is to build a unified performance-based contracting (PBC) framework that incorporates patient access-to-care requirements and that explicitly accounts for the complex outpatient care dynamics facilitated by the use of an online appointment scheduling system. We address the optimal contracting problem in a principal–agent framework where a service purchaser (the principal) minimizes her cost of purchasing the services and achieves the performance target (a waiting-time target) while taking into account the response of the provider (the agent) to the contract terms. Given the incentives offered by the contract, the provider maximizes his payoff by allocating his outpatient service capacity among three patient groups: urgent patients, dedicated advance patients, and flexible advance patients. We model the appointment dynamics as that of an M/D/1 queue and analyze several contracting approaches under adverse selection (asymmetric information) and moral hazard (private actions) settings. Our results show that simple and popular schemes used in practice cannot implement the first-best solution and that the linear performance-based contract cannot implement the second-best solution. To overcome these limitations, we propose a threshold-penalty PBC approach and show that it coordinates the system for an arbitrary patient mix and that it achieves the second-best performance for the setting where all advance patients are dedicated.
Shared Decision Making: Improving Care for Children with Autism
Authors: Golnik Allison , Maccabee-Ryaboy Nadia , Scal Peter , Wey Andrew , Gaillard Philippe
Published: August 2012

We assessed the extent to which parents of children with autism spectrum disorder report that they are engaged in shared decision making. We measured the association between shared decision making and (a) satisfaction with care, (b) perceived guidance regarding controversial issues in autism spectrum disorder, and (c) perceived assistance navigating the multitude of treatment options. Surveys assessing primary medical care and decision-making processes were developed on the basis of the U.S. Department of Health and Human Service's Consumer Assessment of Healthcare Providers and Systems survey. In May 2009, after pilot testing, we sent surveys to 203 parents of children from ages 3 to 18 with International Classification of Diseases–9 and parent-confirmed autism spectrum disorder diagnoses. The response rate was 64%. Controlling for key demographic variables, parents of children with autism spectrum disorder reporting higher levels of shared decision making reported significantly greater satisfaction with the overall quality of their child's health care (p ≤ .0001). Parents reporting higher levels of shared decision making were also significantly more likely to report receiving guidance on the many treatment options (p  =  .0002) and controversial issues related to autism spectrum disorder (p  =  .0322). In this study, shared decision making was associated with higher parent satisfaction and improved guidance regarding treatments and controversial issues within primary care for children with autism spectrum disorder.
Fabrication, Operation, and Health Monitoring of Bender Elements for Aggressive Environments
Authors: Montoya Brina M. , Gerhard Ray , DeJong Jason T. , Wilson Daniel W. , Weil Matthew H. , Martinez Brian C. , Pederson Lars
Published: August 2012

Bender elements are commonly used to monitor the shear wave velocity of soils in various tests, including triaxial, consolidation, and centrifuge tests. When used in aggressive soil environments, electromagnetic crosstalk can distort the received bender element signal, preventing accurate shear wave velocity measurements. Aggressive soil environments are defined herein as conductive soils with high relative permittivity. Under these conditions, the electrical source is transmitted from source to receiver bender, dominating any received shear wave signal propagating through the soil. Careful attention must be paid to reducing the transmission of the electromagnetic signal, particularly in aggressive soil environments. When the waterproof coating of a bender element degrades and the inner and outer electrodes become electrically connected in a saturated environment, the bender element will no longer operate. However, when the waterproofing material is degraded so that only a single electrode on the source element is exposed, electric current can enter the pore fluid and affect the received signal. Further, even if the waterproofing coating is intact, electromagnetic crosstalk from the induced electrical field generated by the transmitting bender element can still affect the received signal when the conductivity of the pore fluid is high. Bender elements can be constructed so as to greatly reduce the electromagnetic crosstalk, and simple tests can be performed to help ensure that the bender element system is not susceptible to crosstalk. The objective here is to present details and practical guidelines regarding the fabrication, operation, and health monitoring of bender elements that will help ensure clear shear wave velocity measurements in aggressive soil environments. The fabrication steps presented improve on previous recommendations. Bender element operation (including signal form, frequency, and amplitude) also affects signal quality and the accuracy of the measured travel time. Finally, recommendations for monitoring the health of the bender elements throughout the transducer life are outlined.
Research on Structural Performance of Conductive Asphalt Pavement Buried Tubes in Moving Load
Authors: Wang Hong , Wu Shaopeng , Wang Genyan
Published: August 2012

The study is focused on the structural performance of conductive asphalt pavement embedded with exchanger tubes, using the finite element method. The pavement structure was modeled as a three-dimensional four-layer stratum using ABAQUS finite element suite. Viscoelastic response models of the asphalt concrete were properly established by using the Prony series. The developed response models were used in finite element simulations on the conductive asphalt pavement. The model of pavement embedded with different types of tubes was subjected to moving load. When the material stress or strain in the layer is computed, the design life can be predicted by using a fatigue model. Finally, the simulating method of the conductive asphalt pavement embedded with tubes was put forward and the study will provide road structural engineers with some design basis.
Mechanical Impedance Measurement on Thin Layer Surface With Impedance Hammer Device
Authors: Li Mingliang , Molenaar A. A. A. , van de Ven M. F. C. , van Keulen Wim
Published: August 2012

The mechanical impedance describes the ability of a structure to resist motion when subjected to a given force. It has received increasing attention as a parameter that could influence the tire/road noise in the medium frequency range (630–1600 Hz). In this study, the impedance hammer device is used for measuring the mechanical impedance on thin layer surface mixture samples in the lab. In the test, the excitation is induced by hitting the sample surface with the hammer. Values of the driving force and acceleration of the vibrating slab are recorded. The mechanical impedance can then be calculated from the ratio of the force to the velocity that is obtained by integration of the acceleration. The influence of the material properties were investigated by comparing the results on different samples. A further measurement of dynamic stiffness on the same material is also discussed and related to the hammer measurement.
Effect of Phase-Change Materials on Thermal and Mechanical Properties of Asphalt Mixtures
Authors: Chen Meizhu , Wan Lu , Lin Juntao
Published: August 2012

The use of phase-change materials (PCMs) in asphalt mixture is expected to solve some problems related to asphalt-pavement temperature, such as rutting behaviors and urban heat island effect. This study mainly evaluated the thermal and mechanical properties of asphalt mixtures with and without various PCMs (PCM-L, PCM-Z) using laboratory performance tests. The experimental tests included thermal conductivity and diffusivity, volumetric heat capacity, indoor temperature changes versus time when heated or cooled, indirect tensile strength, high-temperature rutting, and low-temperature cracking. In addition, a hot disk thermal constants analyzer was used to measure the thermal constants of asphalt mixtures. The results showed that different PCMs had different effects on the thermal constants of asphalt mixtures. Compared with control sample, the sample with PCM-L showed a higher thermal conductivity, whereas the sample with PCM-Z had a lower thermal conductivity. Moreover, PCM-Z exhibited a more-significant phase-change adjusting-temperature effect on asphalt mixtures than PCM-L. However, the addition of PCM to asphalt mixtures resulted in a decreased indirect tensile strength and a weakened rutting resistance, but the effect of PCM-Z was smaller than that of PCM-L. In addition, the asphalt mixture with PCM-Z exhibited better cracking resistance than the mixture with PCM-L and control mixture. Therefore, it is recommended to use PCM-Z in asphalt mixtures to solve the problem of pavement at high temperatures.
Sensing Properties of Carbon Nanotube–Carbon Fiber/Cement Nanocomposites
Authors: Zuo Junqing , Yao Wu , Liu Xiaoyan , Qin Junjie
Published: August 2012

In this work, carbon nanotubes (CNTs) were added into a carbon fiber cement system to produce carbon nanotube–carbon fiber/cement nanocomposites in the form of pastes. The compressive strength, morphology, pressure-sensitive properties, and temperature-sensitive properties were tested. The results show strengthening of the mechanical properties and pressure sensitivity as the CNT content increases from 0.2 % to 1.0 % by mass of cement. The addition of CNTs into cement paste also leads to enhancement of the temperature sensitivity. Additionally, microscopic observation shows that CNTs act as fillers, which results in a dense microstructure of cement paste. Test results indicate that the carbon nanotube–carbon fiber/cement composites show potential either as stress sensors for vehicle detection, weigh-in-motion measurement, and vehicle speed detection or as thermistors for temperature monitoring in concrete structures.
IndependentFLCMutations as Causes of Flowering-Time Variation inArabidopsis thalianaandCapsella rubella
Authors: Guo Ya-Long , Todesco Marco , Hagmann Jörg , Das Sandip , Weigel Detlef
Published: August 2012

Capsella rubella is an inbreeding annual forb closely related to Arabidopsis thaliana, a model species widely used for studying natural variation in adaptive traits such as flowering time. Although mutations in dozens of genes can affect flowering of A. thaliana in the laboratory, only a handful of such genes vary in natural populations. Chief among these are FRIGIDA (FRI) and FLOWERING LOCUS C (FLC). Common and rare FRI mutations along with rare FLC mutations explain a large fraction of flowering-time variation in A. thaliana. Here we document flowering time under different conditions in 20 C. rubella accessions from across the species’ range. Similar to A. thaliana, vernalization, long photoperiods and elevated ambient temperature generally promote flowering. In this collection of C. rubella accessions, we did not find any obvious loss-of-function FRI alleles. Using mapping-by-sequencing with two strains that have contrasting flowering behaviors, we identified a splice-site mutation in FLC as the likely cause of early flowering in accession 1408. However, other similarly early C. rubella accessions did not share this mutation. We conclude that the genetic basis of flowering-time variation in C. rubella is complex, despite this very young species having undergone an extreme genetic bottleneck when it split from C. grandiflora a few tens of thousands of years ago.
Development of a-SiOx:H/a-Si1-xGex:H Tandem Solar Cell for Triple-Junction Solar Cell Applications
Authors: Tseng Y.W. , Lin Y.H. , Hsu H.J. , Hsu C.H. , Tsai C.C.
Published: August 2012

In this work, the development of hydrogenated amorphous silicon oxide (a-SiOx:H) absorber, a-SiOx:H single-junction solar cells and a-SiOx:H/a-Si1-xGex:H tandem solar cells were presented. The oxygen content of the a-SiOx:H materials controlled by changing CO2-to-SiH4 flow ratio had significant influence on its opto-electrical property. As CO2/SiH4 increased from 0 to 2, the bandgap increased from 1.75 to 2.13 eV while the photo-conductivity decreased from 8.25×10-6 to 1.02×10-8 S/cm. Photo-response of over 105 can be obtained as the bandgap was approximately 1.90 eV. The performance of single-junction solar cells revealed a better efficiency can be obtained as the absorber bandgap was in the range of 1.83 to 1.90 eV. Further increase of the absorber bandgap may lead to the increase in bulk defect density which deteriorated the cell efficiency. Finally, a-SiOx:H/a-Si1-xGex:H tandem solar cell was fabricated with the absorber bandgap of 1.90 eV in the top cell. By matching the current between the component cells, the tandem cell efficiency of 7.38% has been achieved.
The influence of prior experience with artificial fruits on the ovipositioning behavior of Anastrepha fraterculus (Diptera, Tephritidae)
Authors: Gregório Patrícia L. F. , Sant'Ana Josué , Redaelli Luiza R. , Idalgo Thiago D. N.
Published: August 2012

The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera, Tephritidae), is a leading pest of Brazilian fruit crops. This study evaluated how prior experience with artificial fruits containing peach and/or guabiroba pulp influenced the ovipositing behavior of A. fraterculus. Insects 15-21 days old were exposed to four treatments: 1) experience with guabiroba, Campomanesia xanthocarpa O. Berg (Myrtaceae); 2) experience with peach, Prunus persica (L.) Batsch (Chimarrita cultivar; Rosaceae); 3) experience with both fruits; and 4) no experience (naive). Naive females and females experienced with guabiroba pulp and with both fruits (peach and guabiroba) oviposited and showed dragging and puncturing behavior on substrates containing guabiroba, but females that were only exposed to peach pulp did not show a preference for any substrate. The study shows that prior experience with substrate influences ovipositing behavior in A. fraterculus.
Synchaeta jollyae (Shiel & Koste) (Rotifera, Synchaetidae): an overlooked species or a newcomer in Neotropical freshwaters?
Authors: Negreiros Natalia F. , Santos Renata M. dos , Oliveira Laira Lúcia Damasceno de , Santos-Wisniewski Maria J. dos , Rocha Odete
Published: August 2012

Populations of Synchaeta jollyae (Shiel & Koste, 1993) (Rotifera), a species recently recorded for the first time in Brazil and South America, were analyzed in reservoirs in Southeast Brazil. Sampling was carried out monthly from August 2006 to July 2007 at Furnas Reservoir in the Rio Grande basin, state of Minas Gerais, and in four cascade reservoirs in the Tietê River basin (Barra Bonita, Bariri, Ibitinga and Nova Avanhandava) state of São Paulo, in June and September 2008 and in January and May 2009. Synchaeta jollyae occurred in most samples and periods. From the results obtained it is evident that S. jollyae occurs in water bodies of varied trophic status but reaches larger populations in eutrophic water bodies and during lower temperature periods. The greatest densities of S. jollyae were found in the eutrophic Bariri Reservoir, on the Tietê River, during the winter. Mann-Whitney test confirmed the significant difference between the population densities in periods of high and low temperatures, with populations reaching higher densities at lower temperatures. It is not yet possible to tell whether S. jollyae is a widely distributed species that has been overlooked in previous plankton studies in South America. Wherever these populations of S. jollyae might have originated, it appears to be a species well established and adapted to a wide range of conditions in the Neotropics.
Distribuição espacial e sazonal de anfíbios em quatro poças na região serrana do Espírito Santo, sudeste do Brasil: influência de corredores florestais
Authors: Ferreira Rodrigo Barbosa , Dantas Roberto de Barros , Tonini João Filipe Riva
Published: August 2012

Este estudo avaliou a composição da anurofauna, bem como a distribuição espacial e temporal das espécies em quatro poças permanentes em uma região montanhosa do Espírito Santo, sudeste do Brasil. Duas dessas poças são conectadas a fragmentos florestais por corredores florestais e as outras duas poças são circundadas por plantação de eucalipto e habitação humana. Foram registradas 22 espécies, incluídas em cinco famílias, entre dezembro de 2003 a novembro de 2004. Hylidae foi a mais rica e abundante, apresentando elevada sobreposição espacial. Nove espécies foram coletadas em vegetação abaixo de 0,60 m, sendo o sítio de vocalização mais utilizado. Riqueza de espécies e abundância foram maiores em meses chuvosos. Poças com corredores abrigaram maior riqueza de espécies. Adicionalmente quatorze espécies foram exclusivamente encontradas nessas poças. A estrutura da comunidade de anuros em poças permanentes nessa paisagem fragmentada é aparentemente determinada pela presença ou ausência de corredores florestais conectando fragmentos em topos de morro às poças d'água ocorrentes ao longo dos vales.
Estructura de la comunidad de macroinvertebrados del arroyo Achiras (Córdoba, Argentina): análisis previo a la construcción de una presa
Authors: Gualdoni Cristina Mabel , Oberto Ana M.
Published: August 2012

La regulación de ríos y arroyos mediante diques modifica parámetros que influyen directamente sobre la biota. En la cuenca endorreica Achiras-del Gato ha finalizado recientemente la construcción de una presa de mediana envergadura que alterará las características limnológicas del sistema y la estructura de las comunidades bentónicas. Este estudio aporta los primeros registros del macrobentos de este sistema lótico y analiza la variación espacio-temporal de la estructura de la comunidad en tramos pedemontanos del arroyo Achiras. Durante un año, antes de la construcción de la presa, se colectaron muestras de zoobentos y se registraron variables abióticas en correderas y rabiones de dos sitios del arroyo, uno situado río arriba del área del dique y otro aguas abajo de la misma. Para cada sitio, hábitat y estación del año se determinó abundancia, frecuencia, riqueza taxonómica, Índice de Shannon y equidad, y se analizaron mediante ANOVA de una y tres vías. Los atributos de las comunidades de referencia se complementaron con la determinación de taxa exclusivos e indicadores y detectores ecológicos. En el primer sitio se registraron 73 taxa, Simulium fue más abundante y Leptohyphes eximius Eaton, 1882, más frecuente. En el segundo se hallaron 75 taxa, Caenis fue más abundante y Cricotopus sp. 3 más frecuente. La abundancia y la riqueza fueron significativamente mayores en primavera, y la diversidad en rabiones de invierno. Se determinó que los atributos de la comunidad estuvieron afectados por la época de muestreo. El arroyo Achiras posee un régimen hídrico freático-pluvial, con caudales bajos en invierno y altos en verano, por lo que se esperan cambios en la biota nativa y la integridad del sistema en respuesta a la reducción de la variabilidad hidráulica cuando el funcionamiento de la presa altere el caudal natural.
Cuatro nuevas especies del grupo Drosophila onychophora (Diptera, Drosophilidae) en el Parque Arqueológico Rumipamba, Pichincha, Ecuador
Authors: Figuero María Luna , León Renata , Rafael Violeta , Céspedes Diego
Published: August 2012

Las especies de los subgéneros Phloridosa y Drosophila (este último en relación con los grupos de especies: D. flavopilosa, D. onychophora y D. bromeliae) son especies de Drosophila que se desarrollan únicamente en flores. El grupo D. onychophora fue propuestopara agrupar a especies exclusivamente antófilas. El grupo D. onychophora está integrado por 18 especies, que se encuentran relacionadas con las flores de Asteraceae. En el Parque Arqueológico Rumipamba, provincia de Pichincha, Ecuador, se realizaron capturas de Drosophila, en los meses de febrero, mayo, julio, septiembre y diciembre del 2009. Las especies fueron recolectadas directamente en las flores con un aspirador entomológico. En total se capturaron 427 individuos de Drosophila y se identificaron 11 especies, de las cuales seis son nuevas especies del grupo D. onychophora y una es un nuevo registro para el Ecuador. En este trabajo se describen cuatro de las seis especies nuevas.
Novos táxons de Lamiinae (Coleoptera, Cerambycidae) da América do Sul
Authors: Galileo Maria Helena M. , Martins Ubirajara R.
Published: August 2012

Novos táxons descritos: Acanthoderini, Nesozineus osorioensis sp. nov., do Brasil (Rio Grande do Sul); Calliini, Drycothaea clara sp. nov., do Brasil (Rondônia) e Drycothaea hovorei sp. nov., do Equador (Napo); Forsteriini, Itacolomi gen. nov., espécie-tipo I. letiziae sp. nov., do Brasil (Minas Gerais); Yapyguara gen. nov., espécie-tipo Y. fusca sp. nov., da Bolívia (Santa Cruz); Xenofreini, Xenofrea zischkai sp. nov., do Equador (Napo) e da Bolívia (Santa Cruz).