bluuebunny/crossref_metadata_2025_split huggingface dataset:
Presynaptic action of neurotensin on dopamine release through inhibition of D2 receptor function
Authors: Fawaz Charbel S , Martel Philippe , Leo Damiana , Trudeau Louis-Eric 
Published: August 2009

AbstractBackgroundNeurotensin (NT) is known to act on dopamine (DA) neurons at the somatodendritic level to regulate cell firing and secondarily enhance DA release. In addition, anatomical and indirect physiological data suggest the presence of NT receptors at the terminal level. However, a clear demonstration of the mechanism of action of NT on dopaminergic axon terminals is lacking. We hypothesize that NT acts to increase DA release by inhibiting the function of terminal D2 autoreceptors. To test this hypothesis, we used fast-scan cyclic voltammetry (FCV) to monitor in real time the axonal release of DA in the nucleus accumbens (NAcc).ResultsDA release was evoked by single electrical pulses and pulse trains (10 Hz, 30 pulses). Under these two stimulation conditions, we evaluated the characteristics of DA D2autoreceptors and the presynaptic action of NT in the NAcc shell and shell/core border region. The selective agonist of D2autoreceptors, quinpirole (1 μM), inhibited DA overflow evoked by both single and train pulses. In sharp contrast, the selective D2receptor antagonist, sulpiride (5 μM), strongly enhanced DA release triggered by pulse trains, without any effect on DA release elicited by single pulses, thus confirming previous observations. We then determined the effect of NT (8–13) (100 nM) and found that although it failed to increase DA release evoked by single pulses, it strongly enhanced DA release evoked by pulse trains that lead to prolonged DA release and engage D2autoreceptors. In addition, initial blockade of D2autoreceptors by sulpiride considerably inhibited further facilitation of DA release generated by NT (8–13).ConclusionTaken together, these data suggest that NT enhances DA release principally by inhibiting the function of terminal D2autoreceptors and not by more direct mechanisms such as facilitation of terminal calcium influx.
Breast, cervical, and colorectal cancer screening rates amongst female Cambodian, Somali, and Vietnamese immigrants in the USA
Authors: Samuel Ponnila S , Pringle Jane P , James Nathaniel W , Fielding Susan J , Fairfield Kathleen M 
Published: August 2009

AbstractIntroductionMinority women, particularly immigrants, have lower cancer screening rates than Caucasian women, but little else is known about cancer screening among immigrant women. Our objective was to assess breast, cervical, and colorectal cancer screening rates among immigrant women from Cambodia, Somalia, and Vietnam and explore screening barriers.MethodsWe measured screening rates by systematic chart review (N = 100) and qualitatively explored screening barriers via face-to-face questionnaire (N = 15) of women aged 50–75 from Cambodia, Somalia, and Vietnam attending a general medicine clinic (Portland, Maine, USA).ResultsChart Review– Somali women were at higher risk of being unscreened for breast, cervical, and colorectal cancer compared with Cambodian and Vietnamese women. A longer period of US residency was associated with being screened for colorectal cancer. We observed a 7% (OR 1.07, 95% CI 1.01–1.13, p = 0.01) increase in the odds that a woman would undergo a fecal occult blood test for each additional year in the US, and a 39% increase in the odds of a woman being screened by colonoscopy or flexible sigmoidoscopy for every five years of additional US residence (OR 1.39, 95% CI 1.21–1.61, p = 0.02). We did not observe statistically significant relationships between odds of being screened by mammography, clinical breast exam or papanicolaou test according to years in the US.Questionnaire– We identified several barriers to breast, cervical, and colorectal cancer screening, including discomfort with exams conducted by male physicians.DiscussionSomali women were less likely to be screened for breast, cervical, and colorectal cancer than Cambodian and Vietnamese women in this population, and uptake of colorectal cancer screening is associated with years of residency in this country. Future efforts to improve equity in cancer screening among immigrants may require both provider and community education.
The Anabaena sensory rhodopsin transducer defines a novel superfamily of prokaryotic small-molecule binding domains
Authors: De Souza Robson F , Iyer Lakshminarayan M , Aravind L 
Published: August 2009

Abstract
The Anabaena sensory rhodopsin transducer (ASRT) is a small protein that has been claimed to function as a signaling molecule downstream of the cyanobacterial sensory rhodopsin. However, orthologs of ASRT have been detected in several bacteria that lack rhodopsin, raising questions about the generality of this function. Using sequence profile searches we show that ASRT defines a novel superfamily of β-sandwich fold domains. Through contextual inference based on domain architectures and predicted operons and structural analysis we present strong evidence that these domains bind small molecules, most probably sugars. We propose that the intracellular versions like ASRT probably participate as sensors that regulate a diverse range of sugar metabolism operons or even the light sensory behavior in Anabaena by binding sugars or related metabolites. We also show that one of the extracellular versions define a predicted sugar-binding structure in a novel cell-surface lipoprotein found across actinobacteria, including several pathogens such as Tropheryma, Actinomyces and Thermobifida. The analysis of this superfamily also provides new data to investigate the evolution of carbohydrate binding modes in β-sandwich domains with very different topologies.
Reviewers: This article was reviewed by M. Madan Babu and Mark A. Ragan.
Genomic profiling of breast tumours in relation to BRCAabnormalities and phenotypes
Authors: Stefansson Olafur Andri , Jonasson Jon Gunnlaugur , Johannsson Oskar Thor , Olafsdottir Kristrun , Steinarsdottir Margret , Valgeirsdottir Sigridur , Eyfjord Jorunn Erla 
Published: August 2009

Abstract
Introduction
Germline mutations in the BRCA1 and BRCA2 genes account for a considerable fraction of familial predisposition to breast cancer. Somatic mutations in BRCA1 and BRCA2 have not been found and the involvement of these genes in sporadic tumour development therefore remains unclear.

Methods
The study group consisted of 67 primary breast tumours with and without BRCA1 or BRCA2 abnormalities. Genomic alterations were profiled by high-resolution (~7 kbp) comparative genome hybridisation (CGH) microarrays. Tumour phenotypes were analysed by immunohistochemistry on tissue microarrays using selected biomarkers (ER, PR, HER-2, EGFR, CK5/6, CK8, CK18).

Results
Classification of genomic profiles through cluster analysis revealed four subgroups, three of which displayed high genomic instability indices (GII). Two of these GII-high subgroups were enriched with either BRCA1- or BRCA2-related tumours whereas the third was not BRCA-related. The BRCA1-related subgroup mostly displayed non-luminal phenotypes, of which basal-like were most prominent, whereas the other two genomic instability subgroups BRCA2- and GII-high-III (non-BRCA), were almost entirely of luminal phenotype. Analysis of genome architecture patterns revealed similarities between the BRCA1- and BRCA2 subgroups, with long deletions being prominent. This contrasts with the third instability subgroup, not BRCA-related, where small gains were more prominent.

Conclusions
The results suggest that BRCA1- and BRCA2-related tumours develop largely through distinct genetic pathways in terms of the regions altered while also displaying distinct phenotypes. Importantly, we show that the development of a subset of sporadic tumours is similar to that of either familial BRCA1- or BRCA2 tumours. Despite their differences, we observed clear similarities between the BRCA1- and BRCA2-related subgroups reflected in the type of genomic alterations acquired with deletions of long DNA segments being prominent. This suggests similarities in the mechanisms promoting genomic instability for BRCA1- and BRCA2-associated tumours, possibly relating to deficiency in DNA repair through homologous recombination. Indeed, this feature characterized both familial and sporadic tumours displaying BRCA1- or BRCA2-like spectrums of genomic alterations. The importance of these findings lies in the potential benefit from targeted therapy, through the use of agents leading to DNA double-strand breaks such as PARP inhibitors (olaparib) and cisplatin, for a much larger group of patients than the few BRCA1 and BRCA2 germline mutation carriers.
Methods for analyzing deep sequencing expression data: constructing the human and mouse promoterome with deepCAGE data
Authors: Balwierz Piotr J , Carninci Piero , Daub Carsten O , Kawai Jun , Hayashizaki Yoshihide , Van Belle Werner , Beisel Christian , van Nimwegen Erik 
Published: August 2009

AbstractWith the advent of ultra high-throughput sequencing technologies, increasingly researchers are turning to deep sequencing for gene expression studies. Here we present a set of rigorous methods for normalization, quantification of noise, and co-expression analysis of deep sequencing data. Using these methods on 122 cap analysis of gene expression (CAGE) samples of transcription start sites, we construct genome-wide 'promoteromes' in human and mouse consisting of a three-tiered hierarchy of transcription start sites, transcription start clusters, and transcription start regions.
Expression and functional characterization of four aquaporin water channels from the European eel (Anguilla anguilla)
Authors: MacIver Bryce , Cutler Christopher P. , Yin Jia , Hill Myles G. , Zeidel Mark L. , Hill Warren G. 
Published: August 2009

SUMMARY
The European eel is a euryhaline teleost which has been shown to differentially up- and downregulate aquaporin (AQP) water channels in response to changes in environmental salinity. We have characterized the transport properties of four aquaporins localized to osmoregulatory organs – gill,esophagus, intestine and kidney. By sequence comparison these four AQP orthologs resemble human AQP1 (eel AQP1), AQP3 (eel AQP3) and AQP10 (AQPe). The fourth member is a duplicate form of AQP1 (AQP1dup) thought to arise from a duplication of the teleost genome. Using heterologous expression in Xenopus oocytes we demonstrate that all four eel orthologs transport water and are mercury inhibitable. Eel AQP3 and AQPe also transport urea and glycerol, making them aquaglyceroporins. Eel AQP3 is dramatically inhibited by extracellular acidity (91% and 69% inhibition of water and glycerol transport respectively at pH 6.5) consistent with channel gating by protons. Maximal water flux of eel AQP3 occurred around pH 8.2 – close to the physiological pH of plasma in the eel. Exposure of AQP-expressing oocytes to heavy metals revealed that eel AQP3 is highly sensitive to extracellular nickel and zinc (88.3% and 86.3% inhibition, respectively) but less sensitive to copper (56.4% inhibition). Surprisingly, copper had a stimulatory effect on eel AQP1 (153.7% activity of control). Copper, nickel and zinc did not affect AQP1dup or AQPe. We establish that all four eel AQP orthologs have similar transport profiles to their human counterparts, with eel AQP3 exhibiting some differences in its sensitivity to metals. This is the first investigation of the transport properties and inhibitor sensitivity of salinity-regulated aquaporins from a euryhaline species. Our results indicate a need to further investigate the deleterious effects of metal pollutants on AQP-containing epithelial cells of the gill and gastrointestinal tract at environmentally appropriate concentrations.
Visual perception of motion in a hunting spider
Authors: Neuhofer Daniela , Machan Rudi , Schmid Axel 
Published: August 2009

SUMMARYLike most other spiders Cupiennius salei (Keyserling 1877) has two different eye types, one pair of principal eyes and three pairs of secondary eyes. The principal eyes have two eye muscles each, which allow movement of the retina and are mainly used for the discrimination of stationary objects. The secondary eyes without such eye muscles are supposed to detect moving objects. Masking experiments were used to analyse the role of these two eye types in motion detection. In a white arena the animals were stimulated with short sequences of moving black bars. The principal eyes move involuntarily when objects are moving within the visual field of an ipsilateral secondary eye. The eye muscle activity of the principal eyes was recorded using single channel telemetry, and activity changes were taken as an indicator for the perception of motion. Masking the principal eyes with black paint and presenting a moving visual stimulus did not modify the induced muscle activity, whereas masking the secondary eyes eliminated the increase in eye muscle activity. This suggests that the secondary eyes are responsible for movement detection. We conclude that the animals are able to detect moving targets visually only with the secondary eyes. The principal eyes, by contrast, do not seem to be involved in the detection of moving targets.
Surface tension propulsion of fungal spores
Authors: Noblin Xavier , Yang Sylvia , Dumais Jacques 
Published: August 2009

SUMMARYMost basidiomycete fungi actively eject their spores. The process begins with the condensation of a water droplet at the base of the spore. The fusion of the droplet onto the spore creates a momentum that propels the spore forward. The use of surface tension for spore ejection offers a new paradigm to perform work at small length scales. However, this mechanism of force generation remains poorly understood. To elucidate how fungal spores make effective use of surface tension, we performed a detailed mechanical analysis of the three stages of spore ejection: the transfer of energy from the drop to the spore, the work of fracture required to release the spore from its supporting structure and the kinetic energy of the spore after ejection. High-speed video imaging of spore ejection in Auricularia auriculaand Sporobolomyces yeasts revealed that drop coalescence takes place over a short distance (∼5 μm) and energy transfer is completed in less than 4 μs. Based on these observations, we developed an explicit relation for the conversion of surface energy into kinetic energy during the coalescence process. The relation was validated with a simple artificial system and shown to predict the initial spore velocity accurately (predicted velocity: 1.2 m s–1; observed velocity: 0.8 m s–1 for A. auricula). Using calibrated microcantilevers, we also demonstrate that the work required to detach the spore from the supporting sterigma represents only a small fraction of the total energy available for spore ejection. Finally, our observations of this unique discharge mechanism reveal a surprising similarity with the mechanics of jumping in animals.
Bone strength is maintained after 8 months of inactivity in hibernating golden-mantled ground squirrels, Spermophilus lateralis
Authors: Utz Jenifer C. , Nelson Stacy , O'Toole Brendan J. , van Breukelen Frank 
Published: August 2009

SUMMARY
Prolonged inactivity leads to disuse atrophy, a loss of muscle and bone mass. Hibernating mammals are inactive for 6–9 months per year but must return to full activity immediately after completing hibernation. This necessity for immediate recovery presents an intriguing conundrum, as many mammals require two to three times the period of inactivity to recover full bone strength. Therefore, if hibernators experience typical levels of bone disuse atrophy during hibernation, there would be inadequate time available to recover during the summer active season. We examined whether there were mechanical consequences as a result of the extended inactivity of hibernation. We dissected femur and tibia bones from squirrels in various stages of the annual hibernation cycle and measured the amount of force required to fracture these bones. Three groups were investigated; summer active animals were captured during the summer and immediately killed, animals in the 1 month detraining group were captured in the summer and killed following a 1-month period of restricted mobility, hibernating animals were killed after 8 months of inactivity. A three-point bend test was employed to measure the force required to break the bones. Apparent flexural strength and apparent flexural modulus (material stiffness) were calculated for femurs. There were no differences between groups for femur fracture force, tibia fracture force, or femur flexural strength. Femur flexural modulus was significantly less for the 1 month detraining group than for the hibernation and summer active groups. Thus, hibernators seem resistant to the deleterious effects of prolonged inactivity during the winter. However, they may be susceptible to immobilization-induced bone loss during the summer.
Osmoregulation and salinity tolerance in the Antarctic midge,Belgica antarctica: seawater exposure confers enhanced tolerance to freezing and dehydration
Authors: Elnitsky Michael A. , Benoit Joshua B. , Lopez-Martinez Giancarlo , Denlinger David L. , Lee Richard E. 
Published: August 2009

SUMMARYSummer storms along the Antarctic Peninsula can cause microhabitats of the terrestrial midge Belgica antarctica to become periodically inundated with seawater from tidal spray. As microhabitats dry, larvae may be exposed to increasing concentrations of seawater. Alternatively, as a result of melting snow or following rain, larvae may be immersed in freshwater for extended periods. The present study assessed the tolerance and physiological response of B. antarctica larvae to salinity exposure, and examined the effect of seawater acclimation on their subsequent tolerance of freezing, dehydration and heat shock. Midge larvae tolerated extended exposure to hyperosmotic seawater; nearly 50% of larvae survived a 10-day exposure to 1000 mOsm kg–1 seawater and ∼25% of larvae survived 6 days in 2000 mOsm kg–1 seawater. Exposure to seawater drastically reduced larval body water content and increased hemolymph osmolality. By contrast,immersion in freshwater did not affect water content or hemolymph osmolality. Hyperosmotic seawater exposure, and the accompanying osmotic dehydration,resulted in a significant correlation between the rate of oxygen consumption and larval water content and induced the de novo synthesis and accumulation of several organic osmolytes. A 3-day exposure of larvae to hyperosmotic seawater increased freezing tolerance relative to freshwater-acclimated larvae. Even after rehydration, the freezing survival of larvae acclimated to seawater was greater than freshwater-acclimated larvae. Additionally, seawater exposure increased the subsequent tolerance of larvae to dehydration. Our results further illustrate the similarities between these related, yet distinct, forms of osmotic stress and add to the suite of physiological responses used by larvae to enhance survival in the harsh and unpredictable Antarctic environment.
Three new, quick CEC methods for determining the amounts of exchangeable calcium cations in calcareous clays
Authors: Dohrmann R. , Kaufhold S. 
Published: August 2009

AbstractThe cation exchange capacity (CEC) is one of the most important properties of clays in terms of their performance in both natural and technical processes. For decades, common methods for determining exchangeable cations have failed when calcareous clays or soils were examined, because calcite is at least partly dissolved throughout the exchange experiment which in turn increases measureable Ca2+ concentrations. As a result, exchangeable Ca2+ and the sum of exchangeable cations by far exceed the amount of negative charges. In the past, the silver-thiourea method (AgTU) has been modified to overcome this problem (AgTUcalcite), but is unsatisfactory as the method is laborious. In the present study three new methods based on two alternative metal complexes, cobalt(III) hexamine (CoHex) and copper(II) triethylenetetramine (Cu-trien), are proposed. The optimum solid/liquid ratios of these methods and the optimum complex concentration of Cu-trien are reported, depending on the mineralogical composition of the samples. The key development is that the exchange solutions are saturated with respect to calcite prior to the experiment. Approximately 70–90% of the dissolution of calcite present as an admixture in a clay sample is suppressed in the subsequent cation exchange experiment, but not all. The Ca2+ exchange is not suppressed and there is no evidence for any precipitation of this Ca2+. Three possibilities for how to handle this problem are discussed, one of which is to perform no further correction. The resulting error arises from the remaining calcite solubility of the different solutions after pre-treatment with calcite. This corresponds to errors of 0.2–1.3 (CoHexcalcite)and 0.7–8.4 (Cu-triencalcite) meq/100 gCa2+ for samples with small and large CEC values, respectively. As a consequence of the poor performance of Cu-triencalcite for samples with large CEC, a more concentrated Cu-trien5 × calcite solution was developed which performed much better: 0.1–0.8 meq/100 g(Cu-trien5 × calcite). For Cu-trien5 × calcite and CoHexcalcite at least, the errors are in the range of the non-systematic scattering for exchangeable Ca2+ determination. Therefore, the methods suggested provide ‘operationally correct’ Ca2+ values without additional effort. Moreover, owing to the high selectivity of the index cations applied in the present study, only one exchange step is required, providing a significant advantage over the AgTUcalcite method.
Factors governing the formation of lithiophorite at atmospheric pressure
Authors: Cui Haojie , You Lei , Feng Xionghan , Tan Wenfeng , Qiu Guohong , Liu Fan 
Published: August 2009

AbstractLithiophorite is a naturally occurring Mn oxide mineral commonly found in soils and sediments. The usual method of synthesizing lithiophorite is via a hydrothermal process in an autoclave at relatively high temperature and pressure. In the present study, an alternative, reflux method, at atmospheric pressure, for synthesis of lithiophorite was developed successfully. The influence of reaction duration, temperature, type of precursor birnessite (H-birnessite, Na-birnessite, aged Na-birnessite), and pH on the formation of lithiophorite were investigated by reflux treatment of lithium-aluminum hydroxide complex ion (

)-exchanged birnessite. The results show that the degree of conversion of lithiophorite decreases with decreasing reaction temperature. Lithiophorite can be obtained at pH values from 5.0 to 9.0, but a circumneutral pH is more favorable for formation at atmospheric pressure. Conversion of Na-birnessite (Bir-OH) to lithiophorite is more favored than aged Na-birnessite (Bir-OH-A). Lithiophorite was not obtained by refluxing the

ion-exchanged H-birnessite (Bir-H) sample. The rate of conversion of lithiophorite increases with increasing reflux time. Lithiophorite synthesized by a reflux process has pseudo-hexagonal crystals of 0.1–0.5 µm with a chemical composition of Li0.24Al0.46MnO2.67(H2O)1.25. The results have important implications for the origin and underlying mechanism of lithiophorite formation in the environment.