bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the disease on female carriers of X-linked lysosomal disorders: a brief review
Authors: Pinto Louise LC , Vieira Taiane A , Giugliani Roberto , Schwartz Ida VD 
Published: May 2010

AbstractMost lysosomal diseases (LD) are inherited as autosomal recessive traits, but two important conditions have X-linked inheritance: Fabry disease and Mucopolysaccharidosis II (MPS II). These two diseases show a very different pattern regarding expression on heterozygotes, which does not seem to be explained by the X-inactivation mechanism only. While MPS II heterozygotes are asymptomatic in most instances, in Fabry disease most of female carriers show some disease manifestation, which is sometimes severe. It is known that there is a major difference among X-linked diseases depending on the cell autonomy of the gene product involved and, therefore, on the occurrence of cross-correction. Since lysosomal enzymes are usually secreted and uptaken by neighbor cells, the different findings between MPS II and Fabry disease heterozygotes can also be due to different efficiency of cross-correction (higher in MPS II and lower in Fabry disease). In this paper, we review these two X-linked LD in order to discuss the mechanisms that could explain the different rates of penetrance and expressivity observed in the heterozygotes; this could be helpful to better understand the expression of X-linked traits.
Evidence for within-individual energy reallocation in cold-challenged, egg-producing birds
Authors: Salvante Katrina G. , Vézina François , Williams Tony D. 
Published: May 2010

SUMMARYRecent studies have shown that the metabolic cost of avian egg production involves a 16–27% increase in metabolic rate (MR) above non-reproductive basal or resting values (BMR and RMR, respectively). To determine how the metabolic cost of egg production interacted with the costs of other essential processes (such as cold acclimation and active heat production), we measured the MR of non-breeding and egg-producing zebra finches (Taeniopygia guttata) while (a) warm-acclimated (to 19–21°C) and measured within their thermoneutral zone (at 35°C), (b) cold-acclimated (to 7°C) and measured at thermoneutrality (at 35°C, i.e. not actively producing heat), and (c) cold-acclimated and measured below thermoneutrality (at 7°C) (i.e. during active heat production). The metabolic cost of egg production was small (24% above BMR) compared with the additive costs of cold acclimation and active heat production (224% above BMR). Exposure to low ambient temperatures was accompanied by an increase in seed consumption (by 72%) and a decrease in locomotor activity (by 72%) compared with warm-acclimated, non-breeding values. By contrast, egg production in heat-producing females was associated with an 11% decrease in MR and a 22% decrease in seed consumption compared with non-breeding thermoregulating values. Our data suggest that while the increase in MR associated with egg production is small in relation to the birds' capacity to increase MR in response to other energetically demanding processes, the addition of egg production to these metabolically costly activities may be enough to necessitate the use of energy-saving strategies, such as internal energy reallocation, to cope with the additional energetic demands.
Directional constraint of endpoint force emerges from hindlimb anatomy
Authors: Bunderson Nathan E. , McKay J. Lucas , Ting Lena H. , Burkholder Thomas J. 
Published: May 2010

SUMMARYPostural control requires the coordination of force production at the limb endpoints to apply an appropriate force to the body. Subjected to horizontal plane perturbations, quadruped limbs stereotypically produce force constrained along a line that passes near the center of mass. This phenomenon, referred to as the force constraint strategy, may reflect mechanical constraints on the limb or body, a specific neural control strategy or an interaction among neural controls and mechanical constraints. We used a neuromuscular model of the cat hindlimb to test the hypothesis that the anatomical constraints restrict the mechanical action of individual muscles during stance and constrain the response to perturbations to a line independent of perturbation direction. In a linearized neuromuscular model of the cat hindlimb, muscle lengthening directions were highly conserved across 10,000 different muscle activation patterns, each of which produced an identical, stance-like endpoint force. These lengthening directions were closely aligned with the sagittal plane and reveal an anatomical structure for directionally constrained force responses. Each of the 10,000 activation patterns was predicted to produce stable stance based on Lyapunov stability analysis. In forward simulations of the nonlinear, seven degree of freedom model under the action of 200 random muscle activation patterns, displacement of the endpoint from its equilibrium position produced restoring forces, which were also biased toward the sagittal plane. The single exception was an activation pattern based on minimum muscle stress optimization, which produced destabilizing force responses in some perturbation directions. The sagittal force constraint increased during simulations as the system shifted from an inertial response during the acceleration phase to a viscoelastic response as peak velocity was obtained. These results qualitatively match similar experimental observations and suggest that the force constraint phenomenon may result from the anatomical arrangement of the limb.
To eat or not to eat: the effect of AICAR on food intake regulation in yellow-bellied marmots (Marmota flaviventris)
Authors: Florant Gregory L. , Fenn Ashley M. , Healy Jessica E. , Wilkerson Gregory K. , Handa Robert J. 
Published: May 2010

SUMMARY
Mammals that hibernate (hibernators) exhibit a circannual rhythm of food intake and body mass. In the laboratory during the winter hibernation period, many hibernators enter a series of multi-day torpor bouts, dropping their body temperature to near ambient, and cease to feed even if food is present in their cage. The mechanism(s) that regulates food intake in hibernators is unclear. Recently, AMP-activated protein kinase (AMPK) has been shown to play a key role in the central regulation of food intake in mammals. We hypothesized that infusing an AMPK activator, 5-aminoimidazole-4-carboxamide 1 B-D-ribofuranoside (AICAR), intracerebroventricularly (ICV) into the third ventricle of the hypothalamus would stimulate yellow-bellied marmots (Marmota flaviventris) to feed during their hibernation season. Infusion of AICAR ICV into marmots at an ambient temperature of 22°C caused a significant (P&lt;0.05) increase in food intake. In addition, animals stimulated to feed did not enter torpor during the infusion period. Marmots ICV infused with saline did not increase food intake and these animals continued to undergo torpor at an ambient temperature of 22°C. Our results suggest that AICAR stimulated the food intake pathway, presumably by activating AMPK. These results support the hypothesis that AMPK may be involved in regulating food intake in hibernators and that there may be common neural pathways involved in regulating feeding and eliciting torpor.
Physiological and immunocytochemical evidence that glutamatergic neurotransmission is involved in the activation of arm autotomy in the featherstarAntedon mediterranea(Echinodermata: Crinoidea)
Authors: Wilkie I. C. , Barbaglio A. , Maclaren W. M. , Carnevali M. D. Candia 
Published: May 2010

SUMMARYThe crinoid echinoderm Antedon mediterranea autotomises its arms at specialised skeletal joints known as syzygies that occur at regular intervals along the length of each arm. Detachment is achieved through the nervously mediated destabilisation of ligament fibres at a particular syzygy. The aim of this investigation was to identify neurotransmitters that are involved in the autotomy response. Physiological experiments were conducted on isolated preparations of syzygial joints, which can be induced to undergo autotomy-like fracture by applying stimulatory agents such as elevated [K+]o. Initial experiments with elevated [K+]o showed that the autotomy threshold (the minimum amount of stimulation required to provoke autotomy) is lowest in syzygies at the arm base and rises distally. Of a range of neurotransmitter agonists tested, only l-glutamate invoked syzygial destabilisation, as did its analogues l-aspartate, α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and kainate, but not l-(+)-2-amino-4-phosphonobutyrate (l-AP4) or N-methyl-d-aspartate (NMDA). The implication that l-glutamate stimulates syzygial fracture through AMPA/kainate-like receptors was supported by the finding that the action of l-glutamate was inhibited by the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Acetylcholine depressed the response of syzygial preparations to l-glutamate, suggesting a possible mechanism by which the autotomy threshold could be varied constitutively and facultatively. An immunocytochemical method employing a polyclonal antibody against l-glutamate conjugated to glutaraldehyde revealed l-glutamate-like immunoreactivity in all components of the putative neural pathway controlling the autotomy reflex, including the epidermis, brachial nerve, syzygial nerves and cellular elements close to the syzygial ligaments. We conclude that it is highly probable that l-glutamate acts as an excitatory neurotransmitter in the activation of arm autotomy in A. mediterranea.
Effects of static magnetic fields on the development and aging ofCaenorhabditis elegans
Authors: Hung Yao-Ching , Lee Jia-Huey , Chen Huang-Meng , Huang Guewha Steven 
Published: May 2010

SUMMARYThe current study investigated the possible effects of static magnetic fields (SMFs) on the developmental and aging processes of Caenorhabditis elegans. Nematodes were grown in the presence of SMFs of strengths varying from 0 to 200 mT. The rate of development and the lifespan were recorded. Treatment with a 200 mT SMF reduced the development time from the L2 to the L3 stage by 20%, from L3 to L4 by 23%, and from L4 to young adult by 31%. After SMF treatment, the average lifespan was reduced from 31 days to 24 days for wild-type nematodes. The up-regulation of clk-1, lim-7, daf-2, unc-3 and age-1 after SMF treatment was verified by quantitative real-time RT-PCR. Apparently, induction of gene expression is selective and dose dependent. The total developmental time was significantly reduced for the lin-4, lin-14, lin-41 and lim-7 mutants, but not for the let-7, clk-1, unc-3 and age-1 mutants. Lifespan analyses revealed that the let-7, unc-3 and age-1 mutants were not affected by SMF treatment. Here we show that SMFs accelerate nematode development and shorten nematode lifespan through pathways associated with let-7, clk-1, unc-3 and age-1.
Numerical simulation of a pectoral fin during labriform swimming
Authors: Shoele Kourosh , Zhu Qiang 
Published: May 2010

SUMMARYWe numerically examine the fluid–structure interaction and force generation of a skeleton-reinforced fin that geometrically, structurally and kinematically resembles the pectoral fin of a fish during labriform swimming. This fin contains a soft membrane with negligible bending stiffness and 12 embedded rays (modeled as beams). A potential flow-based boundary element model is applied to solve the fluid flow around the fin, in which the vorticity field is modeled as thin vorticity sheets shed from prescribed locations (the sharp trailing edge). The fin motion is actuated by dorsoventral and anteroposterior rotations of the rays (the motion of each ray is controlled individually), as well as pitching motion of the baseline. Consequently, the fin undergoes a combination of flapping (lift-based) and rowing (drag-based) motions typical in labriform swimming. The fin motion contains two strokes: a recovery stroke and a power stroke. The performance of the fin depends upon kinematic parameters such as the Strouhal number, the phase lag between rays, the pitching motion of the baseline and the passive deformations of the rays. The most interesting finding is that the strengthening of the ray at the leading edge plays a pivotal role in performance enhancement by reducing the effective angle of attack and decreasing the power expenditure during the recovery stroke.
Feasting, fasting and freezing: energetic effects of meal size and temperature on torpor expression by little brown batsMyotis lucifugus
Authors: Matheson Amanda L. , Campbell Kevin L. , Willis Craig K. R. 
Published: May 2010

SUMMARYTorpor is an adaptation for energy conservation employed by many species of small-bodied endotherms. However, surprisingly little is known regarding proximate factors influencing day-to-day variation in torpor expression in the wild. We used open-flow respirometry to quantify torpor expression in nine little brown bats (Myotis lucifugus, LeConte 1831) at two ambient temperatures (7°C and 17°C) following either sham feeding or consumption of a high-protein meal (50% or 100% of the mass required to reach satiation for each individual). Food consumption significantly increased the time spent normothermic before torpor entry but did not affect either the rate of body cooling or torpid metabolic rate. Bats did not fully exploit potential energy savings by maximising their use of torpor. Instead they varied torpor expression such that total energy expenditure over the course of each 22-h trial was balanced against gross energy intake immediately before the trial, independent of ambient temperature. This was accomplished by adjusting the timing of entry into torpor (thus altering the time spent torpid), rather than by modulating torpid metabolic rate. However, pre-trial body mass was also a significant predictor of torpor expression, which suggests that energy reserves combine with recent foraging success to influence individuals' decisions about depth and duration of their torpor bouts. We also present evidence that little brown bats use the heat generated through digestion (i.e. the heat increment of feeding) to substitute for active thermogenesis at sub-thermoneutral temperatures, thereby reducing the energetic costs of thermoregulation prior to torpor entry.
G-proteins modulate invertebrate synaptic calcium channel (LCav2) differently from the classical voltage-dependent regulation of mammalian Cav2.1 and Cav2.2 channels
Authors: Huang Xuan , Senatore Adriano , Dawson Taylor F. , Quan Quyen , Spafford John David 
Published: May 2010

SUMMARY
Voltage-gated calcium channels in the Cav2 channel class are regulators of synaptic transmission and are highly modified by transmitter inputs that activate synaptic G-protein-coupled receptors (GPCRs). A ubiquitous form of G-protein modulation involves an inhibition of mammalian Cav2.1 and Cav2.2 channels by Gβγ dimers that can be relieved by high-frequency trains of action potentials. Here, we address whether the ubiquitous and versatile form of G-protein regulation in mammals is also found in simpler invertebrate nervous systems. Remarkably, the invertebrate LCav2 channel from the pond snail, Lymnaea stagnalis, does not bear any of the hallmarks of mammalian, voltage-dependent G-protein inhibition of Cav2.2. Swapping either the I-II linker or N-terminus of Cav2.2, which serve as key binding domains for G-protein inhibition, does not endow invertebrate LCav2 channels with voltage-dependent G-protein modulatory capacity. Instead, in vitro expressed LCav2 channels are inhibited slowly by the activation of cAMP, in a manner that depends on G-proteins but does not depend on Gβγ subunits. A similar G-protein and cAMP-dependent inhibition of nifedipine-insensitive LCav2 currents is also consistent in native and identified Lymnaea VD4 neurons. The slower inhibition using a cellular messenger such as cAMP may meet the modulatory needs in invertebrates while an activity-dependent regulation, evolving in vertebrates, provides a more dynamic, fine-tuning of neurosecretion by regulating the influence of neurotransmitter inputs through presynaptic GPCRs.
Aquatic feeding in pipid frogs: the use of suction for prey capture
Authors: Carreño Carrie A. , Nishikawa Kiisa C. 
Published: May 2010

SUMMARYInertial suction feeding is the most common method of prey capture among aquatic vertebrates. However, it had been unclear whether the aquatic frogs in the family Pipidae also used inertial suction for prey capture. In this study, we examined feeding behavior in four species of pipids, Pipa pipa, Xenopus laevis, Hymenochirus boettgeri and Pseudhymenochirus merlini. Pressure in the buccopharyngeal cavity was measured during prey capture. These pressure measurements were coupled with high-speed recordings of feeding behavior. For each species, the internal buccopharyngeal pressure was found to drop significantly below ambient pressure, and changes in pressure corresponded with the onset of mouth opening. Kinematic analysis revealed that all species of pipids generated subambient pressure during prey capture; H. boettgeri and P. merlini relied solely on inertial suction feeding. Pipa pipa and X. laevis additionally employed forelimb scooping during prey capture but both of these species demonstrated the ability to capture prey with inertial suction alone. Based on buccopharyngeal pressure measurements as well as kinematic analyses, we conclude that inertial suction feeding is used during prey capture in these four species of pipids.
Roles of Mono- and Divalent Cations in DNA Compaction Induced by Histone-Mimic Nanoparticles
Authors: Takenaka Toshio , Zinchenko Anatoly A , Yoshikawa Kenichi , Murata Shizuaki 
Published: May 2010

Abstract
The compaction of gene-size T4 DNA induced by the action of silica nanoparticles (10–100 nm diameter), the surfaces of which were modified to various degrees by a 3-aminopropylsilyl groups, was monitored by a fluorescent microscope in an aqueous solution. It was found that DNA compaction was facilitated by mono- and divalent cations such as Na+, K+, Mg2+, and Ca2+. This promotion by cations was the result of charge-neutralization of DNA and was more remarkable in compaction by histone-size nanoparticles (10 nm) than in that by larger ones (&gt;15 nm). Divalent metal ions were more effective at promoting compaction due to their greater charge-neutralizing character, but a quaternary diammonium derivative of 1,3-propanediamine deactivated DNA compaction by 10-nm nanoparticles. Although metal ions binding to DNA can reduce electrostatic tension on DNA and provide flexibility to create a DNA loop with a small diameter, such ammonium dication does not make DNA sufficiently flexible.
The Effects of Online User Reviews on Movie Box Office Performance: Accounting for Sequential Rollout and Aggregation Across Local Markets
Authors: Chintagunta Pradeep K. , Gopinath Shyam , Venkataraman Sriram 
Published: May 2010

Our objective in this paper is to measure the impact (valence, volume, and variance) of national online user reviews on designated market area (DMA)-level local geographic box office performance of movies. We account for three complications with analyses that use national-level aggregate box office data: (i) aggregation across heterogeneous markets (spatial aggregation), (ii) serial correlation as a result of sequential release of movies (endogenous rollout), and (iii) serial correlation as a result of other unobserved components that could affect inferences regarding the impact of user reviews. We use daily box office ticket sales data for 148 movies released in the United States during a 16-month period (out of the 874 movies released) along with user review data from the Yahoo! Movies website. The analysis also controls for other possible box office drivers. Our identification strategy rests on our ability to identify plausible instruments for user ratings by exploiting the sequential release of movies across markets—because user reviews can only come from markets where the movie has previously been released, exogenous variables from previous markets would be appropriate instruments in subsequent markets. In contrast with previous studies that have found that the main driver of box office performance is the volume of reviews, we find that it is the valence that seems to matter and not the volume. Furthermore, ignoring the endogenous rollout decision does not seem to have a big impact on the results from our DMA-level analysis. When we carry out our analysis with aggregated national data, we obtain the same results as those from previous studies, i.e., that volume matters but not the valence. Using various market-level controls in the national data model, we attempt to identify the source of this difference. By conducting our empirical analysis at the DMA level and accounting for prerelease advertising, we can classify DMAs based on their responsiveness to firm-initiated marketing effort (advertising) and consumer-generated marketing (online word of mouth). A unique feature of our study is that it allows marketing managers to assess a DMA's responsiveness along these two dimensions. The substantive insights can help studios and distributors evaluate their future product rollout strategies. Although our empirical analysis is conducted using motion picture industry data, our approach to addressing the endogeneity of reviews is generalizable to other industry settings where products are sequentially rolled out.
Mesh-Free Solution of Two-Dimensional Edge Crack Problems under Thermo-Mechanical Load
Authors: Pant Mohit , Singh I. V. , Mishra B. K. , Bhasin Vivek , Sharma Kamal , Khan I. A. 
Published: May 2010

Abstract
In this work, a mesh-free approach known as element free Galerkin method (EFGM) has been used to obtain the solution of two-dimensional edge crack problems in linear elastic fracture mechanics subjected to thermo-mechanical loads. The diffraction criterion has been modified with multiple crack weight technique to characterize the presence of all cracks in the domain of the influence of a node. The effect of crack orientation has been studied for two edge cracks lying on the same face as well as on opposite faces under plane stress conditions. The values of mode-I and mode-II stress intensity factors have been evaluated by domain based interaction integral approach. The results obtained by EFGM are compared with those obtained by finite element method.
Phase Change and Mechanical Behaviors of TixCoCrFeNiCu1−yAly High Entropy Alloys
Authors: Zhang Y. , Chen G. L. , Gan C. L. 
Published: May 2010

Abstract
The alloying effects of the Al, Ti, Cu, and Co in a typical TixCoCrFeNiCu1−yAly high entropy alloy (HEA) were systematically studied. The phase change of the HEAs is closely related to the atomic packing efficiency of the phases. The high entropy of the alloy will largely lower the Gibbs free energy when the enthalpy of the alloys are not changed too much, and the high entropy phase can be an equilibrium stable one. The HEAs can have ultrahigh fracture strength at room temperature and high temperature, e.g., yield strength of 1400 MPa at 500°C.