bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE MECHANICS OF HEARING: A COMPARATIVE CASE STUDY IN BIO-MATHEMATICAL MODELLING
Authors: CHAMPNEYS A. R. , AVITABILE D. , HOMER M. , SZALAI R. 
Published: December 2011

AbstractA synthesis is presented of two recent studies on modelling the nonlinear neuro-mechanical hearing processes in mosquitoes and in mammals. In each case, a hierarchy of models is considered in attempts to understand data that shows nonlinear amplification and compression of incoming sound signals. The insect’s hearing is tuned to the vicinity of a single input frequency. Nonlinear response occurs via an arrangement of many dual capacity neuro-mechanical units called scolopidia within the Johnston’s organ. It is shown how the observed data can be captured by a simple nonlinear oscillator model that is derived from homogenization of a more complex model involving a radial array of scolopidia. The physiology of the mammalian cochlea is much more complex, with hearing occurring via a travelling wave along a tapered, compartmentalized tube. Waves travel a frequency-dependent distance along the tube, at which point they are amplified and “heard”. Local models are reviewed for the pickup mechanism, within the outer hair cells of the organ of Corti. The current debate in the literature is elucidated, on the relative importance of two possible nonlinear mechanisms: active hair bundles and somatic motility. It is argued that the best experimental agreement can be found when the nonlinear terms include longitudinal coupling, the physiological basis of which is described. A discussion section summarizes the lessons learnt from both studies and attempts to shed light on the more general question of what constitutes a good mathematical model of a complex physiological process.
Molecular Gas in Galaxies at all Redshifts
Authors: Combes Françoise 
Published: December 2011

AbstractI review some recent results about the molecular content of galaxies, obtained essentially from the CO lines, but also dense tracers, or the dust continuum emission. New results have been obtained on molecular cloud physics, and their efficiency to form stars, shedding light on the Kennicutt-Schmidt law as a function of surface density and galaxy type. Large progress has been made on galaxy at moderate and high redshifts, allowing to interprete the star formation history and star formation efficiency as a function of gas content, or galaxy evolution. In massive galaxies, the gas fraction was higher in the past, and galaxy disks were more unstable and more turbulent. ALMA observations will allow the study of more normal galaxies at high z with higher spatial resolution and sensitivity.
Gas and Dust in M33
Authors: Braine J. , Gratier P. , Kramer C. , Mookerjea B. , Xilouris M. , Calzetti D. 
Published: December 2011

AbstractWe present results from the Herschel and IRAM projects to map M33 in the dust continuum and main emission lines, particularly C[II] and CO. The temperature of the cool dust decreases with distance from the center of M33 from ~25K to ~13K. The CO emission generally follows the dust temperature and the overall dust emission. However, about 1/6 of the molecular clouds are not associated with massive stars, such that about 1/6th the lifetime of an entity identifiable as a molecular cloud is in a pre-star formation state. These clouds are less CO-bright than those with massive stars. The largest sample of molecular clouds currently available for an external galaxy shows that the cloud CO luminosity function, usually viewed as the cloud H2 mass, steepens with radius such that smaller clouds are more numerous in the outer parts. The observations of the C[II] line with Herschel indicate that the C[II] emission traces on-going star formation rather than the neutral gas. This identification will be tested via velocity-resolved Herschel/HIFI C[II] spectra in the near future.
HI and Hα Mapping of M31 & M33
Authors: Kam Z. S. , Carignan C. , Chemin L. , Hernandez O. , de Denus-Baillargeon M. , Djabo Y. 
Published: December 2011

RésuméWe performed a deep Hi and Hα mapping of M31 and M33 in order to get accurate kinematical data of those two galaxies and also to make a comparison between the Hi and Hα kinematics. The Hi data were obtained with the DRAO interferometer and the Hα data with the Fabry-Perot system of the Observatoire du mont Mégantic using an EMCCD as a detector. These data will give us the best possible datasets to derive accurate rotation curves and mass models for those two Local Group spirals and provide some new data for the Hii regions studies of these galaxies. While the Hi observations are of low resolution (~1 arcmin), the high resolution of the Hα data (~1 arcsec) should allow us to get much more details in the central regions, allowing at the same time a much better determination of the kinematical parameters. Hence, the inner part of the rotation curve, so inportant to constraint properly the mass models, will be determined more accurately.
Star Formation in Isolated LIRGs: Clues to Star-forming Processes at Higher z
Authors: Fuentes-Carrera Isaura , Olguín Lorenzo , Ambrocio-Cruz Patricia , Verley Simon , Rosado Margarita , Verdes-Montenegro Lourdes , Repetto Paolo , Vázquez Celia , Aguilera Verónica 
Published: December 2011

AbstractLuminous infrared galaxies (LIRGs) are galaxies with LIR > 1011 L⊙. For a star-forming galaxy to emit at a LIRG level, it must have a very high star formation rate (SFR). In the local Universe, the star formation (SF) is primarily triggered by interactions. However, at intermediate redshift, a large fraction of LIRGs are disk galaxies with little sign of recent merger activity. The question arises whether the intermediate redshift LIRGs are “triggered” or experiencing “normal”, if elevated, SF. Understanding these SF processes is important since this type of systems may have contributed to 20% or more of the cosmic SFR in the early Universe. In order to address this issue we study similar systems in the Local Universe, that is isolated late-type galaxies displaying LIRG activity. We use different observational techniques in order to trace the star-forming history of these systems. Here we present preliminary results.
Quantifying the Redistribution of Mass in Galactic Disks due to Bars
Authors: Sánchez-Blázquez Patricia , Pérez Isabel , Ocvirk Pierre 
Published: December 2011

AbstractNumerical simulations have shown that strong gravitational torque by non-axisymmetric components induce evolutionary processes such as redistribution of mass and angular momentum in the galactic disks and consequent change of chemical abundance profiles. If we hope to understand chemical evolution gradients and their evolution we must understand the secular processes and re-arrangement of material by non-axisymmetric components and vice-versa. The most obvious of these aforementioned non-axisymmetric components are bars - at least 2/3 of spiral galaxies host a bar, and possibly all disk galaxies have hosted a bar at some point in their evolution. While observationally it has been found that barred galaxies have shallower gas-phase metallicity gradients than non-barred galaxies, a complementary analysis of the stellar abundance profiles has not yet been undertaken. This is unfortunate because the study of both gas and stars is important in providing a complete picture, as the two components undergo (and suffer from) very different evolutionary process. We present here a pilot study of the gas and stellar metallicity and age distributions in a sample of barred and non-barred galaxies using 2D spectroscopic observations. We found that the majority of the stellar mass in our sample is composed of old (~10 Gyr) stars. This is true in the bulge and the disc region, even beyond two disc scalelengths. In the disc region, a larger fraction of young stars is present in the external parts of the disc compared with the inner disc. The disc growth is, therefore, compatible with a moderate inside-out formation scenario, where the luminosity-weighted age changes from ~10 Gyrs in the centre, to ~4 Gyrs at two disc scalelengths, depending upon the galaxy. However, the presence of substructure, like star forming rings, can produce stellar population trends that are not directly related with the growing of the disc but to the bar potential. In the disc region, the metallicity gradient always decrease with the radius. In the bulge region this is not always true and we find inverse metallicity gradients in several galaxies.
Environmental Effects in Galaxy Clusters: Infalling Groups in Abell 85 and 1367
Authors: Bravo-Alfaro H. , Scott T. C. , Brinks E. , Cortese L. , Granados P. , Navarro-Poupard F. , Mayya Y. D. , Durret F. 
Published: December 2011

AbstractWe are carrying out a multifrequency survey of late type galaxies in nearby clusters with the aim to investigate the effects exerted by both the very local and the global cluster environments. We report new VLA-HI images of galaxies in Abell 1367 and study the evolution of their gaseous component. In Abell 85 we perform a deep NIR imaging survey of the brightest spirals projected up to 1.0 Abell radius with the aim of unveiling possible gravitational effects on their stellar disks. Here we show preliminary results of these projects, mainly focused on infalling compact groups of galaxies moving towards their respective cluster centers.
Epidermal growth factor induces tumour marker AKR1B10 expression through activator protein-1 signalling in hepatocellular carcinoma cells
Authors: Liu Ziwen , Yan Ruilan , Al-Salman Ahmed , Shen Yi , Bu Yiwen , Ma Jun , Luo Di-Xian , Huang Chenfei , Jiang Yuyang , Wilber Andrew , Mo Yin-Yuan , Huang Mei Chris , Zhao Yupei , Cao Deliang 
Published: December 2011

AKR1B10 (aldo-keto reductase 1B10) is overexpressed in liver and lung cancer, and plays a critical role in tumour development and progression through promoting lipogenesis and eliminating cytotoxic carbonyls. AKR1B10 is a secretory protein and potential tumour marker; however, little is known about the regulatory mechanism of AKR1B10 expression. The present study showed that AKR1B10 is induced by mitogen EGF (epidermal growth factor) and insulin through the AP-1 (activator protein-1) signalling pathway. In human HCC (hepatocellular carcinoma) cells (HepG2 and Hep3B), EGF (50 ng/ml) and insulin (10 nM) stimulated endogenous AKR1B10 expression and promoter activity. In the AKR1B10 promoter, a putative AP-1 element was found at bp −222 to −212. Deletion or mutation of this AP-1 element abrogated the basal promoter activity and response to EGF and AP-1 proteins. This AP-1 element bound to nuclear proteins extracted from HepG2 cells, and this binding was stimulated by EGF and insulin in a dose-dependent manner. Chromatin immunoprecipitation showed that the AP-1 proteins c-Fos and c-Jun were the predominant factors bound to the AP-1 consensus sequence, followed by JunD and then JunB. The same order was followed in the stimulation of endogenous AKR1B10 expression by AP-1 proteins. Furthermore, c-Fos shRNA (short hairpin RNA) and AP-1 inhibitors/antagonists (U0126 and Tanshinone IIA) inhibited endogenous AKR1B10 expression and promoter activity in HepG2 cells cultured in vitro or inoculated subcutaneously in nude mice. U0126 also inhibited AKR1B10 expression induced by EGF. Taken together, these results suggest that AKR1B10 is up-regulated by EGF and insulin through AP-1 mitogenic signalling and may be implicated in hepatocarcinogenesis.
Seasonally Dynamic Diel Vertical Migrations of Mysis diluviana, Coregonine Fishes, and Siscowet Lake Trout in the Pelagia of Western Lake Superior
Authors: Ahrenstorff Tyler D. , Hrabik Thomas R. , Stockwell Jason D. , Yule Daniel L. , Sass Greg G. 
Published: December 2011

AbstractDiel vertical migrations are common among many aquatic species and are often associated with changing light levels. The underlying mechanisms are generally attributed to optimizing foraging efficiency or growth rates and avoiding predation risk (μ). The objectives of this study were to (1) assess seasonal and interannual changes in vertical migration patterns of three trophic levels in the Lake Superior pelagic food web and (2) examine the mechanisms underlying the observed variability by using models of foraging, growth, and μ. Our results suggest that the opossum shrimp Mysis diluviana, kiyi Coregonus kiyi, and siscowet lake trout Salvelinus namaycush migrate concurrently during each season, but spring migrations are less extensive than summer and fall migrations. In comparison with M. diluviana, kiyis, and siscowets, the migrations by ciscoes C. artedi were not as deep in the water column during the day, regardless of season. Foraging potential and μ probably drive the movement patterns of M. diluviana, while our modeling results indicate that movements by kiyis and ciscoes are related to foraging opportunity and growth potential and receive a lesser influence from μ. The siscowet is an abundant apex predator in the pelagia of Lake Superior and probably undertakes vertical migrations in the water column to optimize foraging efficiency and growth. The concurrent vertical movement patterns of most species are likely to facilitate nutrient transport in this exceedingly oligotrophic ecosystem, and they demonstrate strong linkages between predators and prey. Fishery management strategies should use an ecosystem approach and should consider how altering the densities of long‐lived top predators produces cascading effects on the nutrient cycling and energy flow in lower trophic levels.
Effect of Predators on Growth and Reproductive Investment in Bluegills: Comparison of Populations with Differing Size and Age of Maturation
Authors: Oplinger Randall W. , Wahl David H. , Nannini Michael A. 
Published: December 2011

AbstractGrowth rate and age of maturation are two important factors that control adult body size. Predators can also exert an influence on the size and age of maturation of their prey. We compared the growth, timing of maturation, and investment in gonad development of bluegills Lepomis macrochirus in ponds with and without largemouth bass Micropterus salmoides predators. In addition, we compared the response between bluegills from stunted (small size and early age of maturation) and nonstunted (larger size and later age of maturation) populations to determine whether predation could explain the occurrence of stunted body size in bluegills. For both males and females, we found that bluegills grew faster but matured at the same rate in the presence of predators. The investment in gonad development (measured by the gonadosomatic index) did not differ between individuals raised with predators and those raised without. Regardless of predator treatment, fish from the nonstunted population grew more than those from the stunted population and invested less energy in gonad development. The interaction between population source and predator presence was not significant, suggesting that the observed predator responses did not differ between bluegills from the stunted and nonstunted populations. These results support the hypothesis that predators have a strong influence on the life history of the bluegill. Bluegills grew more in the presence of predators, but this did not result in a corresponding reduction in the investment in reproduction.
Effects of short‐term lifestyle activity modification on adiponectin mRNA expression and plasma concentrations
Authors: Moghadasi Mehrzad , Mohebbi Hamid , Rahmani‐Nia Farhad , Hassan‐Nia Sadegh , Noroozi Hamid 
Published: December 2011

AbstractAdiponectin mRNA and plasma concentrations were reduced in obesity. Exercise training may reduce the adipose tissue (AT), although it is not well known, whether exercise – induced change in AT, increases adiponectin mRNA expression and plasma concentrations or not. Therefore, the purpose of this study was to examine the effects of short‐term lifestyle activity modification (LAM) on adiponectin mRNA and plasma concentrations. Sixteen obese and overweight middle‐aged men (age, 35–50 years) with type 2 diabetes participated in this study. The subjects were randomly assigned to LAM group (n=8) or control group (n=8). The subjects in LAM group walked two miles in 30 min on a treadmill on 4 days per week for 12 weeks according to the guidelines of the Centers for Disease Control and Prevention and American College of Sports Medicine. The results showed that body mass, body mass index, central visceral adipose tissue and subcutaneous adipose tissue volume and hip and thigh subcutaneous adipose tissue (hip and thigh SAT) volume were decreased in the LAM group compared to the control group (P<0.05). Adiponectin mRNA in abdominal and gluteal subcutaneous AT were increased significantly in the LAM group compared to the control group (P<0.05), while plasma adiponectin concentrations, hs‐CRP and insulin resistance did not change significantly. In conclusion, adiponectin mRNA levels increase after 12 weeks of LAM; however, plasma adiponectin levels were not affected by this protocol in obese and overweight middle‐aged men with type 2 diabetes.
Motor performance and bodyweight of children and adolescents in Saarland – Status quo
Authors: Klein Markus , Fröhlich Michael , Emrich Eike 
Published: December 2011

AbstractThe motor performance of children and adolescents has been a subject of controversial discussion. As part of a pilot project, 839 schoolchildren from 14 different schools in Saarland were studied and their height, weight and sport motor performance were measured using the German motor performance test DMT 6‐18. The results show a slight increase in the number of overweight children compared to reference samples. However, these discrepancies are minor and cannot be judged to be practically relevant because of the weakness of the effects. The average motor test performances of the Saarland schoolchildren were above the average performance of the reference samples in almost all individual performances. There are also hardly any weaker performances in comparison to older studies. The current results for motor performance of Saarland children and adolescents do not, therefore, give any great reason for concern. Further evaluation steps will be needed to clarify the influences that might be associated with adverse characteristics for motor performance (socio‐economic status, living situation, leisure behaviour, school performance, etc.).
Response timing in the lunge and target change in elite versus medium‐level fencers
Authors: Gutierrez‐Davila Marcos , Rojas Francisco J. , Antonio Raquel , Navarro Enrique 
Published: December 2011

AbstractThe aim of the present work is to examine the differences between two groups of fencers with different levels of competition, elite and medium level. The timing parameters of the response reaction have been compared together with the kinetic variables which determine the sequence of segmented participation used during the lunge with a change in target during movement. A total of 30 male sword fencers participated, 13 elite and 17 medium level. Two force platforms recorded the horizontal component of the force and the start of the movement. One system filmed the movement in 3D, recording the spatial positions of 11 markers, while another system projected a mobile target over a screen. For synchronisation, an electronic signal enabled all the systems to be started simultaneously. Among the timing parameters of the reaction response, the choice reaction time (CRT) to the target change during the lunge was measured. The results revealed differences between the groups regarding the flight time, horizontal velocity at the end of the acceleration phase, and the length of the lunge, these being higher for the elite group, as well as other variables related to the temporal sequence of movement. No significant differences have been found in the simple reaction time or in CRT. According to the literature, the CRT appears to improve with sports practice, although this factor did not differentiate the elite from medium‐level fencers. The coordination of fencing movements, that is, the right technique, constitutes a factor that differentiates elite fencers from medium‐level ones.
Effect of skill level on cardiorespiratory and metabolic responses during Tai Chi training
Authors: Xiong Kai‐Yu , He Hui , Ni Guo‐Xin 
Published: December 2011

AbstractNowadays, Tai chi chuan (TCC) is practiced by millions worldwide with a range of skill levels. However, the effect of skill level on physiological response to TCC performance has yet to be clarified. In this study, physiological parameters during practicing simplified 24‐form TCC were investigated and compared in 10 young high‐level (HL) male TCC athletes and 10 ordinary‐level (OL) male TCC practitioners with similar age and body size. Significantly higher energy expenditure, heart rate, oxygen uptake and tidal volume were found in HL group than OL group during TCC performance. The respiratory frequency and exhalation time were similar between the two groups during practicing TC; however, significantly less inhalation time was found in HL group (1.02±0.2 s) than OL group (1.12±0.28 s). Our results suggested that skill level may have considerable impact on metabolic and cardiorespiratory responses to TCC performance. TCC practitioners with different skill levels may practice TCC in different ways, which was supposed to lead to distinguishable response between the two groups.
Differences in energy expenditure between high‐ and low‐volume training
Authors: Drenowatz Clemens , Eisenmann Joey C. , Pivarnik James M. , Pfeiffer Karin A. , Carlson Joseph J. 
Published: December 2011

AbstractSeveral studies have examined energy expenditure in various sports but there is a lack of research on the contribution of exercise and habitual activity during different training periods. This study examined changes in total daily energy expenditure (TDEE) and its components during high‐ and low‐volume training periods. Further, changes in time spent in sedentary, light, moderate and vigorous activity in response to different training volumes were explored. Energy expenditure was measured in 15 male endurance athletes during 2 non‐consecutive weeks – 1 week of high volume (>13 hours) training and another week of low volume (<7 hours) training. The SenseWear Pro 3 Armband, individual heart‐rate‐oxygen consumption regression and indirect calorimetry was used to measure non‐exercise activity thermogensis (NEAT), exercise energy expenditure (EEE) and resting metabolic rate, respectively. Time spent at different intensities was assessed using previously established MET cutpoints. TDEE as well as EEE increased significantly with higher training volume, while no difference in NEAT occurred. Further, significantly less time was spent in sedentary activities during the high‐volume week. These results suggest that highly trained athletes do not compensate for increased training volume and reduce sedentary activities to allow for more training time.