bluuebunny/crossref_metadata_2025_split huggingface dataset:
Omcg1 is critically required for mitosis in rapidly dividing mouse intestinal progenitors and embryonic stem cells
Authors: Léguillier Teddy , Vandormael-Pournin Sandrine , Artus Jérôme , Houlard Martin , Picard Christel , Bernex Florence , Robine Sylvie , Cohen-Tannoudji Michel 
Published: June 2012

Summary
Recent studies have shown that factors involved in transcription-coupled mRNA processing are important for the maintenance of genome integrity. How these processes are linked and regulated in vivo remains largely unknown. In this study, we addressed in the mouse model the function of Omcg1, which has been shown to participate in co-transcriptional processes, including splicing and transcription-coupled repair. Using inducible mouse models, we found that Omcg1 is most critically required in intestinal progenitors. In absence of OMCG1, proliferating intestinal epithelial cells underwent abnormal mitosis followed by apoptotic cell death. As a consequence, the crypt proliferative compartment of the small intestine was quickly and totally abrogated leading to the rapid death of the mice. Lack of OMCG1 in embryonic stem cells led to a similar cellular phenotype, with multiple mitotic defects and rapid cell death. We showed that mutant intestinal progenitors and embryonic stem cells exhibited a reduced cell cycle arrest following irradiation, suggesting that mitotic defects may be consecutive to M phase entry with unrepaired DNA damages. These findings unravel a crucial role for pre-mRNA processing in the homeostasis of the small intestine and point to a major role of OMCG1 in the maintenance of genome integrity.
Coordination of bat sonar activity and flight for the exploration of three-dimensional objects
Authors: Genzel Daria , Geberl Cornelia , Dera Thomas , Wiegrebe Lutz 
Published: June 2012

SUMMARY
The unique combination of flight and echolocation has opened the nocturnal air space as a rich ecological niche for bats. By analysing echoes of their sonar emissions, bats discriminate and recognize three-dimensional (3-D) objects. However, in contrast to vision, the 3-D information that can be gained by ensonifying an object from only one observation angle is sparse. To date, it is unclear how bats synchronize echolocation and flight activity to explore the 3-D shape of ensonified objects. We have devised an experimental design that allows creating 3-D virtual echo-acoustic objects by generating in real-time echoes from the bat's emissions that depend on the bat's position relative to the virtual object. Bats were trained to evaluate these 3-D virtual objects differing in their azimuthal variation of either echo amplitude or spectral composition. The data show that through a very effective coordination of sonar and flight activity, bats analyse an azimuthal variation of echo amplitude with a resolution of approximately 16 dB and a variation of echo centre frequency of approximately 19%. Control experiments show that the bats can detect not only these variations but also perturbations in the spatial arrangement of these variations. The current experimental paradigm shows that echolocating bats assemble echo-acoustic object information – acquired sequentially in flight – to reconstruct the 3-D shape of the ensonified object. Unlike previous approaches, the recruitment of virtual objects allows for a direct quantification of this reconstruction success in a highly controlled experimental approach.
The role of elastic energy storage and recovery in downhill and uphill running
Authors: Snyder Kristine L. , Kram Rodger , Gottschall Jinger S. 
Published: June 2012

SUMMARY
In level running, humans and other animals store and recover elastic energy during each step. What role does elastic energy play during downhill and uphill running? We measured the fluctuations of the mechanical energy of the center of mass (CoM) of 15 human participants running at 3 m s–1 on the level, downhill and uphill on a force-measuring treadmill mounted at 3, 6 and 9 deg. In level running, nearly symmetrical decreases and increases of the combined gravitational potential and kinetic (GPE+KE) energy of the CoM indicated equal possible elastic energy storage and recovery. However, asymmetrical fluctuations during hill running indicate reduced maximum possible elastic energy storage and return. We analyzed mechanical energy generation and dissipation during level and hill running by quantifying the anatomically estimated elastic energy storage (AEEE) in the arch and Achilles' tendon using peak ground reaction forces and anatomical characteristics. AEEE did not change with grade. At shallow downhill grades, the body must generate mechanical energy, though it dissipates more than it generates. At steeper downhill grades, little to no energy generation is required and only mechanical energy dissipation must occur. The downhill grade at which mechanical energy must no longer be generated occurs at approximately –9 deg, near the metabolically optimal running grade. At shallow uphill grades, mechanical energy must be generated to raise the CoM, and at steeper grades, additional energy must be generated to offset reduced elastic energy storage and return.
Spectral sensitivity of phototaxis in the dinoflagellateKryptoperidinium foliaceumand their reaction to physical encounters
Authors: Moldrup Morten , Garm Anders 
Published: June 2012

SUMMARYThe dinoflagellate Kryptoperidinium foliaceum possesses one of the largest eyespots among the autotrophic dinoflagellates. Until now they were believed to be negatively phototactic using a non-opsin photopigment. Here we provide evidence that in newly established cultures they are positively phototactic and that the dynamic range of phototaxis is ∼2.5 log units. Additionally, we find that the spectral sensitivity of the phototaxis agrees reasonably well with the absorption curve of a theoretical opsin, with a peak sensitivity around 500 nm. The sensitivity in the short wavelength end of the tested spectrum is unexpectedly low, but this is probably due to selective filtering. Interestingly, the phototaxis could be temporarily overruled by tactile stimuli. After physical contact with the light guide, the cells escaped the area, and we suggest that this may serve as predator avoidance.
Pheromone mediated modulation of pre-flight warm-up behavior in male moths
Authors: Crespo José G. , Goller Franz , Vickers Neil J. 
Published: June 2012

SUMMARYAn essential part of sexual reproduction typically involves the identification of an appropriate mating partner. Males of many moth species utilize the scent of sex pheromones to track and locate conspecific females. However, before males engage in flight, warm-up by shivering of the major flight muscles is necessary to reach a thoracic temperature suitable to sustain flight. Here we show that Helicoverpa zea males exposed to an attractive pheromone blend (and in some instances to the primary pheromone component alone) started shivering earlier and took off at a lower thoracic temperature than moths subjected to other incomplete or unattractive blends. This resulted in less time spent shivering and faster heating rates. Two interesting results emerge from these experiments. First, the rate of heat generation can be modulated by different olfactory cues. Second, males detecting the pheromone blend take off at lower thoracic temperatures than males exposed to other stimuli. The take-off temperature of these males was below that for optimal power production in the flight muscles, thus generating a trade-off between rapid departure and suboptimal flight performance. Our results shed light on thermoregulatory behaviour of unrestrained moths associated with the scramble competition for access to females and suggest ecological trade-offs between rapid flight initiation and sub-optimal flight performance.
Development of cardiovascular function in the marine gastropodLittorina obtusata(Linnaeus)
Authors: Bitterli Tabitha S. , Rundle Simon D. , Spicer John I. 
Published: June 2012

SUMMARYThe molluscan cardiovascular system typically incorporates a transient extracardiac structure, the larval heart, early in development, but the functional importance of this structure is unclear. We documented the ontogeny and regulatory ability of the larval heart in relation to two other circulatory structures, the true heart and the velum, in the intertidal gastropod Littorina obtusata. There was a mismatch between the appearance of the larval heart and the velum. Velar lobes appeared early in development (day 4), but the larval heart did not begin beating until day 13. The beating of the larval heart reached a maximum on day 17 and then decreased until the structure itself disappeared (day 24). The true heart began to beat on day 17. Its rate of beating increased as that of the larval heart decreased, possibly suggesting a gradual shift from a larval heart-driven to a true heart-driven circulation. The true heart was not sensitive to acutely declining PO2 shortly after it began to beat, but increased in activity in response to acutely declining PO2 by day 21. Larval heart responses were similar to those of the true heart, with early insensitivity to declining PO2 (day 13) followed by a response by day 15. Increased velum-driven rotational activity under acutely declining PO2 was greatest in early developmental stages. Together, these findings point to cardiovascular function in L. obtusata larvae being the result of a complex interaction between velum, larval and true heart activities, with the functions of the three structures coinciding but their relative importance changing throughout larval development.
The discerning predator: decision rules underlying prey classification by a mosquito-eating jumping spider
Authors: Nelson Ximena J. , Jackson Robert R. 
Published: June 2012

SUMMARYEvarcha culicivora is an East African jumping spider that feeds indirectly on vertebrate blood by choosing blood-fed female Anopheles mosquitoes as prey. Previous studies have shown that this predator can identify its preferred prey even when restricted to using only visual cues. Here, we used lures and virtual mosquitoes to investigate the optical cues underlying this predator's prey-choice behaviour. We made lures by dissecting and then reconstructing dead mosquitoes, combining the head plus thorax with different abdomens. Depending on the experiment, lures were either moving or motionless. Findings from the lure experiments suggested that, for E. culicivora, seeing a blood-fed female mosquito's abdomen on a lure was a necessary, but not sufficient, cue by which preferred prey was identified, as cues from the abdomen needed to be paired with cues from the head and thorax of a mosquito. Conversely, when abdomens were not visible or were identical, spiders based their decisions on the appearance of the head plus thorax of mosquitoes, choosing prey with female characteristics. Findings from a subsequent experiment using animated 3D virtual mosquitoes suggest that it is specifically the mosquito's antennae that influence E. culicivora's prey-choice decisions. Our results show that E. culicivora uses a complex process for prey classification.
Inter-animal variability in the effects of C-type allatostatin on the cardiac neuromuscular system in the lobster Homarus americanus
Authors: Wiwatpanit Teerawat , Powers Brian , Dickinson Patsy S. 
Published: June 2012

SUMMARY
Although the global effects of many modulators on pattern generators are relatively consistent among preparations, modulators can induce different alterations in different preparations. We examined the mechanisms that underlie such variability in the modulatory effects of the peptide C-type allatostatin (C-AST; pQIRYHQCYFNPISCF) on the cardiac neuromuscular system of the lobster Homarus americanus. Perfusion of C-AST through the semi-intact heart consistently decreased the frequency of ongoing contractions. However, the effect of C-AST on contraction amplitude varied between preparations, decreasing in some preparations and increasing in others. To investigate this variable effect, we examined the effects of C-AST both peripherally and centrally. When contractions of the myocardium were elicited by controlled stimuli, C-AST did not alter heart contraction at the periphery (myocardium or neuromuscular junction) in any hearts. However, when applied either to the semi-intact heart or to the cardiac ganglion (CG) isolated from hearts that responded to C-AST with increased contraction force, C-AST increased both motor neuron burst duration and the number of spikes per burst by about 25%. In contrast, CG output was increased only marginally in hearts that responded to C-AST with a decrease in contraction amplitude, suggesting that the decrease in amplitude in those preparations resulted from decreased peripheral facilitation. Our data suggest that the differential effects of a single peptide on the cardiac neuromuscular system are due solely to differential effects of the peptide on the pattern generator; the extent to which the peptide induces increased burst duration is crucial in determining its overall effect on the system.
Formation of Porous Pt Nanoparticles through Core–Shell Pt–Al Nanoalloys and Wet Chemical Etching
Authors: Shen Zhongrong , Matsuki Yasuo , Higashimine Koichi , Miyake Mikio , Shimoda Tatsuya 
Published: June 2012

Abstract
We introduce a strategy for preparation of porous Pt nanoparticles with high catalytic activity and large surface area by changing the morphology of large-sized Pt nanoparticle into Pt–Al nanoalloy, then following a simple wet-chemical etching to remove partial Al.
Review of the Safety and Efficacy of Exenatide Once Weekly for the Treatment of Type 2 Diabetes Mellitus
Authors: Murphy Catherine E 
Published: June 2012

OBJECTIVE: To summarize and evaluate the available literature assessing the efficacy and safety of exenatide once weekly for the treatment of type 2 diabetes mellitus. DATA SOURCES: PubMed (1966-January 2012) and International Pharmaceutical Abstracts (1969-January 2012) were searched using the term exenatide once weekly. Abstracts presented at the European Association for the Study of Diabetes Annual Meeting in 2011 and reference citations from publications were reviewed for inclusion. Eli Lilly and Company and Amylin Pharmaceuticals were contacted for additional unpublished information. STUDY SELECTION AND DATA EXTRACTION: All English-language articles and abstracts were evaluated for inclusion. All randomized controlled trials were included in the review. DATA SYNTHESIS: The efficacy and safety of exenatide once weekly has been evaluated as initial monotherapy and as add-on therapy to metformin, sulfonylureas, and thiazolidinediones in patients with uncontrolled type 2 diabetes for up to 3 years. Results from 6 randomized, comparator-controlled studies in over 3000 patients indicate that treatment with exenatide once weekly results in significant glycemic improvements and weight loss. Gastrointestinal adverse effects and injection site reactions are common, but rarely lead to drug discontinuation. CONCLUSIONS: Exenatide once weekly holds promise as a convenient, efficacious, and well-tolerated antihyperglycemic agent for the treatment of type 2 diabetes. Studies evaluating outcomes such as cardiovascular events or all-cause mortality with exenatide once weekly are lacking.
Identification of Follistatin-Like 1 by Expression Cloning as an Activator of the Growth Differentiation Factor 15 Gene and a Prognostic Biomarker in Acute Coronary Syndrome
Authors: Widera Christian , Giannitsis Evangelos , Kempf Tibor , Korf-Klingebiel Mortimer , Fiedler Beate , Sharma Sarita , Katus Hugo A , Asaumi Yasuhide , Shimano Masayuki , Walsh Kenneth , Wollert Kai C 
Published: June 2012

Abstract

BACKGROUND
Growth differentiation factor 15 (GDF15) is a stress-responsive cytokine and biomarker that is produced after myocardial infarction and that is related to prognosis in acute coronary syndrome (ACS). We hypothesized that secreted proteins that activate GDF15 production may represent new ACS biomarkers.

METHODS
We expressed clones from an infarcted mouse heart cDNA library in COS1 cells and assayed for activation of a luciferase reporter gene controlled by a 642-bp fragment of the mouse growth differentiation factor 15 (GDF15) gene promoter. We measured the circulating concentrations of follistatin-like 1 (FSTL1) and GDF15 in 1369 patients with ACS.

RESULTS
One cDNA clone that activated the GDF15 promoter–luciferase reporter encoded the secreted protein FSTL1. Treatment with FSTL1 activated GDF15 production in cultured cardiomyocytes. Transgenic production of FSTL1 stimulated GDF15 production in the murine heart, whereas cardiomyocyte-selective deletion of FSTL1 decreased production of GDF15 in cardiomyocytes, indicating that FSTL1 is sufficient and required for GDF15 production. In ACS, FSTL1 emerged as the strongest independent correlate of GDF15 (partial R2 = 0.26). A total of 106 patients died of a cardiovascular cause during a median follow-up of 252 days. Patients with an FSTL1 concentration in the top quartile had a 3.7-fold higher risk of cardiovascular death compared with patients in the first 3 quartiles (P &lt; 0.001). FSTL1 remained associated with cardiovascular death after adjustment for clinical, angiographic, and biochemical variables.

CONCLUSIONS
Our study is the first to use expression cloning for biomarker discovery upstream of a gene of interest and to identify FSTL1 as an independent prognostic biomarker in ACS.
Learning-by-Exporting, Introduction of New Products, and Product Rationalization: Evidence from Korean Manufacturing
Authors: Hahn Chin Hee 
Published: June 2012

Abstract
Utilizing a previously unexplored plant-product matched dataset in the Korean manufacturing sector, this paper examines the impact of exporting on firms’ productivity and the mechanism by which it operates. We find strong evidence for the learning-by-exporting hypothesis. We also find that exporting induces plants to introduce new products and rationalize their products beginning from one year prior to, and until two years after, export market entry. The synchronous responses of product churning and TFP suggest that new-product introduction and product rationalization are indeed one mechanism of the learning-by-exporting effect. Finally, we find that plants increase, rather than decrease, their product scope after exporting, in contrast with the prediction from the recent theories of multi-product firms.
Teaching medical professionals and trainees about adolescent suicide prevention: five key problems
Authors: Sher Leo 
Published: June 2012

Abstract
Predicting and preventing suicide represent very difficult challenges for clinicians. The awareness of adolescent suicide as a major social and medical problem has increased over the past years. However, many health care professionals who have frequent contact with adolescents are not sufficiently trained in suicide evaluation techniques and approaches to adolescents with suicidal behavior. Suicide prevention efforts among adolescents are restricted by the fact that there are five key problems related to the evaluation and management of suicidality in adolescents: 1. Many clinicians underestimate the importance of the problem of adolescent suicidal behavior and underestimate its prevalence. 2. There is a misconception that direct questioning of adolescents about suicidality is sufficient to evaluate suicide risk. 3. Another misconception is that adolescents with non-psychiatric illnesses do not need to be evaluated for suicidality. 4. Many clinicians do not know about or underestimate the role of contagion in adolescent suicidal behavior. 5. There is a mistaken belief that adolescent males are at lower suicide risk than adolescent females. Educating medical professionals and trainees about the warning signs and symptoms of adolescent suicide and providing them with tools to recognize, evaluate, and manage suicidal patients represent a promising approach to adolescent suicide prevention.
Prevalence of common mental disorders among Dutch medical students and related use and need of mental health care: a cross-sectional study
Authors: Gaspersz Roxanne , Frings-Dresen Monique H.W. , Sluiter Judith K. 
Published: June 2012

Abstract
Objective: The purpose of the study was to assess common mental disorders and the related use and need for mental health care among clinically not yet active and clinically active medical students.
Methods: All medical students (n=2266) at one Dutch medical university were approached. Students from study years 1–4 were defined as clinically not yet active and students from study years 5 and 6 as clinically active. An electronic survey was used to detect common mental disorders depression (BSI-DEP), anxiety (BSI-ANG), stress (4DSQ) and post-traumatic stress disorder (IES). The use of mental health services in the past 3 months and the need for mental health services were asked for. The prevalence of common mental disorders, the use and need for mental health services and differences between groups were calculated.
Results: The response rate was 52%: 814 clinically not yet active and 316 clinically active students. The prevalence of common mental disorders among clinically not yet active and clinically active students was 54% and 48%, respectively. The use of mental health services was 14% in clinically not yet active and 12% in clinically active students with common mental disorders (n.s.). The need for mental health services by clinically not yet active and clinically active students was 52% and 46%, respectively (n.s.).
Conclusions: The prevalence of probable common mental disorders are higher among clinically not yet active than among clinically active students. The need of mental health services exceeds use, but is the same in the two groups of students.
Late diagnosis of Cushing’s disease in a child: what lessons can be learned?1)
Authors: Gust Deborah Anne , Gordon Thomas P. 
Published: June 2012

Abstract
We present a case of late diagnosis of an adolescent female with Cushing’s disease or excess glucocorticoid secretion due to the presence of an adrenocorticotropic hormone (ACTH) secreting tumor on the pituitary. Her main complaints at first presentation in 2008 were short stature and weight gain. Although these are the main criteria for testing for Cushing’s syndrome outlined by the 2008 Endocrine Society guidelines, they were not enough to lead to a timely diagnosis. The reasons may include the endocrinologists believing that additional more common symptoms needed to be present to test for Cushing’s syndrome. Consequently, the guidelines were not followed leading to placing the child on growth hormone (GH) with no further evaluation until well after 1 year of minimal growth. While Cushing’s syndrome is rare in children and hard to diagnose, a more collaborative effort among pediatricians, endocrinologists, radiologists, surgeons, as well as parents, is required to diagnose and help cure children with this disease.