cssi/SciSciGPT-SciSciNet huggingface dataset:
Sustained Overexpression of IGF-1 Prevents Age-Dependent Decrease in Charge Movement and Intracellular Ca2+ in Mouse Skeletal Muscle

In this work we tested the hypothesis that transgenic sustained overexpression of IGF-1 prevents age-dependent decreases in charge movement and intracellular Ca(2+) in skeletal muscle fibers. To this end, short flexor digitorum brevis (FDB) muscle fibers from 5-7- and 21-24-month-old FVB (wild-type) and S1S2 (IGF-1 transgenic) mice were studied. Fibers were voltage-clamped in the whole-cell configuration of the patch-clamp technique according to described procedures (Wang, Z. M., M. L. Messi, and O. Delbono. 1999. Biophys. J. 77:2709-2716). Charge movement and intracellular Ca(2+) concentration were recorded simultaneously. The maximum charge movement (Q(max)) recorded in young wild-type and transgenic mice was (mean +/- SEM, in nC microF(-1)): 52 +/- 2.1 (n = 46) and 54 +/- 1.9 (n = 38) (non-significant, ns), respectively, whereas in old wild-type and old transgenic mice the values were 36 +/- 2.1 (n = 32) and 49 +/- 2.3 (n = 35), respectively (p < 0.01). The peak intracellular calcium [Ca(2+)](i) recorded in young wild-type and transgenic mice was (in muM): 14.5 +/- 0.9 and 16 +/- 2.1 (ns), whereas in old wild-type and transgenic mice the values were 9.9 +/- 0.1 and 14 +/- 1.1 (p < 0.01), respectively. No significant changes in the voltage distribution or steepness of the Q-V or [Ca(2+)]-V relationship were found. These data support the concept that overexpression of IGF-1 in skeletal muscle prevents age-dependent reduction in charge movement and peak [Ca(2+)](i).
Bainbridge sets the stage on scaling in fish swimming.

![Graphic][1] This classic by Richard Bainbridge is the first of three data papers ([Bainbridge, 1958][2]; [Bainbridge, 1960][3]; [Bainbridge, 1962][4]) on the scaling of swimming motions and performance in fishes. When published, a quarter century had passed since the earlier key 1933
Theory and applications of fluorescence spectroscopy in food research

Abstract Fluorescence spectroscopy is a rapid, sensitive method for characterizing molecular environments and events. In spite of its utility, food researchers have been slow to adopt fluorescence methodology, partly because its value has gone unrecognized. This article presents a brief overview of the theory of fluorescence spectroscopy, together with some examples of applications of this technique to illustrate its potential for addressing key problems in food science.
Forms of Predation: Tiger and Markhor Hunting in Colonial Governance*

In this paper I compare late nineteenth and early twentieth-century sport hunting of markhor, a mountain goat, by British civil and military officials in the mountainous northern frontier region of Kashmir State, with their hunting of tigers, particularly man-eating tigers in the hilly and plains regions of India. Using these two instances, this paper elucidates and compares two competing visions of colonial governance. The British sportsman hunted man-eating tigers in order to protect Indian society from wild nature. Hunting them was also symbolic of their welfare-oriented governance ideology. They also hunted markhor in the northern mountainous region using begar, or forced labour, which they justified by falling back on the wider colonial representation of the northern mountainous region as a civilization-less area, where a more coercive form of governance was needed. So, rather than protecting society from nature, as in the case of man-eating tiger hunting in the plains, what was needed in the mountains was the ability of the British to introduce civilization into unruly nature via a strong disciplinary force. I argue that colonial governance entailed not simply a struggle to civilize India and its population, but a more profound struggle for control over nature.
On the mechanism of acetate enhancement of renal p-aminohippurate transport.

The effect of acetate on the ability of renal cortical tissue to accumulate and to synthesize p-aminohippurate was determined in young and adult rats. Acetate increased the maximal rate of p-aminohippurate uptake in tissue from adult rats with no change in Km values. The effect of acetate on p-aminohippurate accumulation by renal cortical slices from adult rats was smaller than that from rabbits but the stimulatory effect was apparent. The p-aminohippurate slice/medium (SM) ratio was increased at high pH (8.2) and acetate increased further the p-aminohippurate SM ratio in both age groups. The ability of renal cortical homogenates to synthesize p-aminohippurate was used to estimate the activity of the enzyme glycine acyltransferase (EC 2.3.1.13). Enzyme activity was low in renal cortical homogenates from 10-day-old rats when measured under optimal conditions and with glycine rate limiting. Acetate did not change p-aminohippurate synthesis in tissues from young or adult rats. These data discount the hypothesis that acetate enhancement of p-aminohippurate transport is due to the formation of acetylglycine.
Spaceflight Environment Induces Mitochondrial Oxidative Damage in Ocular Tissue

A recent report shows that more than 30% of the astronauts returning from Space Shuttle missions or the International Space Station (ISS) were diagnosed with eye problems that can cause reduced visual acuity. We investigate here whether spaceflight environment-associated retinal damage might be related to oxidative stress-induced mitochondrial apoptosis. Female C57BL/6 mice were flown in the space shuttle Atlantis (STS-135), and within 3–5 h of landing, the spaceflight and ground-control mice, similarly housed in animal enclosure modules (AEMs) were euthanized and their eyes were removed for analysis. Changes in expression of genes involved in oxidative stress, mitochondrial and endothelial cell biology were examined. Apoptosis in the retina was analyzed by caspase-3 immunocytochemical analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. Levels of 4-hydroxynonenal (4-HNE) protein, an oxidative specific marker for lipid peroxidation were also measured. Evaluatio...
Metastatic epidural osteosarcoma initially diagnosed as cisplatin neuropathy

Unexpected early epidural spinal metastatis in a case of osteosarcoma occurred in a patient receiving treatment with cis-diamminedichloroplatinum-II (cisplatin). The initial neurologic symptomatology manifested as paresthesias in the feet which developed 2 months after initiation of treatment (cumulative dose of cisplatin 450 mg/M2) at which stage the primary tumor demonstrated a marked response. Concurrently two small pulmonary metastases appeared. Epidural metastasis in osteosarcoma is generally considered a late complication and is usually associated with disseminated disease. This communication draws attention to changes in the metastatic pattern which may occur with the administration of seemingly effective treatment and the potential for confusing the symptomatology of epidural spinal metastasis with cisplatin neuropathy.
Mitochondrial inner membrane electrophysiology assessed by rhodamine-123 transport and fluorescence.

Rhodamine-123 is widely used to make dynamic measurements of mitochondrial membrane potential both in vitro and in situ. Yet data interpretation is difficult due to a lack of quantitative understanding of how membrane potential and measured fluorescence are related. To develop such understanding, a model for dye transport across the mitochondrial inner membrane and partition into the membrane was developed. The model accounts for experimentally measured dye self-quenching and was integrated into a model of mitochondrial electrophysiology to estimate transients in mitochondrial membrane potential from kinetic fluorescence measurements. Our analysis indicates that (i) R123 fluorescence peaks at concentrations near 50 μM due to self-quenching; (ii) measured fluorescence intensity and membrane potential are related by a non-linear calibration curve sensitive to certain experimental details, including total concentration of dye and mitochondria in suspensions; and (iii) the time courses of membrane potential and electron transport fluxes following a perturbation (i.e. addition of ADP) significantly differ from observed transients in fluorescence intensity. These findings are consistent with the model predictions that mitochondria display a characteristic time of response to changes in substrate concentration of less than 0.1 s, corresponding to the time scale over which the rate of ATP synthesis changes to meet changes in ADP concentration.
Controlling Solid-State Reaction Pathways: Composition Dependence in the Nucleation Energy of InSe

The crystallization of InSe from bulk amorphous indium−selenium alloys was studied as a function of composition. The composition dependence of the nucleation energy of InSe from amorphous alloys was determined using a Kissinger analysis of differential scanning calorimetry data. A minimum in the nucleation energy was found for the one-to-one composition. This minimum reflects the maximum driving force per unit volume found for this composition as well as the lack of short-range composition fluctuations required to nucleate stoichiometric InSe from nonstoichiometric amorphous alloys.
In Defense of Unanimous Jury Verdicts: Mistrials, Communication, and Strategic Voting

The requirement of unanimous jury verdicts in criminal trials is widely believed to reduce the likelihood of convicting the innocent. This belief depends largely upon the assumption that jurors will vote nonstrategically based on their impression of the trial evidence. Recent literature, however, has questioned this assumption, and Feddersen and Pesendorfer propose a model in which it is never a Nash equilibrium for jurors to vote nonstrategically under unanimity rule, and equilibrium behavior produces higher probabilities of both convicting the innocent and acquitting the guilty under unanimity rule than under numerous alternatives. I extend this work by incorporating two additional features of actual jury procedure: the possibility of mistrial and communication among jurors. Under each circumstance, I demonstrate that nonstrategic voting is a Nash equilibrium under fairly general conditions and that unanimity performs better than any alternative rule in minimizing probability of trial error and maximizing expected utility.
Class-II neurons display a higher degree of stochastic synchronization than class-I neurons

We describe the relationship between the shape of the phase-resetting curve (PRC) and the degree of stochastic synchronization observed between a pair of uncoupled general oscillators receiving partially correlated Poisson inputs in addition to inputs from independent sources. We use perturbation methods to derive an expression relating the shape of the PRC to the probability density function (PDF) of the phase difference between the oscillators. We compute various measures of the degree of synchrony and cross correlation from the PDF's and use the same to compare and contrast differently shaped PRCs, with respect to their ability to undergo stochastic synchronization. Since the shape of the PRC depends on underlying dynamical details of the oscillator system, we utilize the results obtained from the analysis of general oscillator systems to study specific models of neuronal oscillators. It is shown that the degree of stochastic synchronization is controlled both by the firing rate of the neuron and the membership of the PRC (type I or type II). It is also shown that the circular variance for the integrate and fire neuron and the generalized order parameter for a hippocampal interneuron model have a nonlinear relationship to the input correlation.
An intrinsic equation of interfacial motion for the solidification of a pure hypercooled melt

Abstract Solidification of a pure hypercooled melt is studied in the case where heat diffusion is localized within a narrow boundary layer along the solid-liquid interface. An intrinsic coordinate system, based on the distance to the interface, and a perturbation expansion in the boundary layer thickness are used to derive an expression for the normal velocity of the interface as a function of the local surface geometry. This intrinsic equation of motion represents an extension of the ideas of long-wave theories. We identify and examine a co-dimension two limit in this theory in which two terms may vanish corresponding to small front speed and marginal long-wave stability. Two special geometries are considered: near-planar and near-spherical interfaces. For near-planar interfaces, long-wave theory yields a modified Kuramoto-Sivashinsky equation. We analytically examine the bifurcation of steady planform solutions (i.e. rolls, squares and hexagons) from a planar interface, and numerically extend the roll solutions into the fully non-linear regime. In certain cases, an analytical solution suggests that some periodic disturbances will grow without bound. For spherical particles, we identify a critical growth radius (below which particles shrink) and an instability radius, above which non-spherical deformations are amplified. The intrinsic coordinate methodology developed here should be applicable to many other problems in interface motion including directional solidification, solidification of a dilute binary alloy and reaction-diffusion and phase-field models that mimic solidification dynamics.
Continuous recollection versus unitized familiarity in associative recognition.

Recollection has long been thought to play a key role in associative recognition tasks. Evidence that associative recollection might be a threshold process has come from analyses of the associative recognition Receiver Operating Characteristic (ROC). Specifically, the ROC is not as curvilinear as a signal-detection theory requires. In addition, the z-ROC is usually curvilinear, as a threshold recollection model requires, not linear, as a signal-detection model requires. In Experiment 1, word pairs were strengthened at study, which yielded a curvilinear ROC and a linear z-ROC (in accordance with signal-detection theory). This result suggests that associative recognition performance was based on a continuous variable, one that likely consists either of unitized familiarity or continuous recollection. The Remember/Know procedure and an unexpected cued recall test suggested that the more curvilinear ROC in the strong condition was mainly due to increased recollection. In Experiment 2, word pairs were presented for an old/new recognition decision before being presented for an associative recognition decision. When pairs consisting of items not recognized as having been seen on the list were removed from the analysis, the ROC again became curvilinear, the z-ROC again became linear, and most associative recognition decisions were associated with Remember judgments. These findings suggest that the curvilinear z-ROC often observed on associative recognition tests results from noise, as a mixture signal-detection model assumes, and that recollection is a continuous process that yields a curvilinear ROC that is well characterized by signal-detection theory.
Measurements of the relative output factors for CyberKnife collimators.

OBJECTIVE: To determine accurately the relative output factors, defined as the ratio of the nominal dose rate for a given collimator to that of the 60-mm collimator. This is particular important for radiosurgical treatment of functional disorders, such as trigeminal neuralgia, inj which a single large radiation dose is delivered to the target with a small collimator, such as the 5-mm collimator for CyberKnite radiosurgery. Numerous studies on the output factors have been reported for the Leksell gamma knife unit but none for the CyberKnife system. METHODS: Measurements of the relative output factors for all 12 collimators were periformed by three different methods, silicon diode, radiographic film, and thermoluminescent dosimetry microcybes. The silicon diode is designed for measurements in amall (1-50 MV) photon beams performed in water or air. Film and thermoiuminescent dosimetry measurements were performed in a plastic phantom. RESULTS: The measured relative output factors for the three methods were very similar except for the three smallest colimators (5, 7.5, and 10 mm). The measured difference between the above methods was approximately 2%. The mean value of the output factor for the 5-mm collimator was 0.686 ± 0.024. The uncertainties of the output factors are expected to increase with the decrease of collimator diameter. They range from approximately 1 to 4% of the relative output factor. CONCLUSlON: The relative output factor can be measured with an acceptable accuracy even for the smallest (5-mm) CyberKnife collimators. This requires the selection of appropriate dosimetric delectors and measuring procedures. The results obtained with the diode are considered more accurate than with the other two methods.
A precise numerical prediction of effective dielectric constant for polymer-ceramic composite based on effective-medium theory

Nanostructure polymer-ceramic composite with high dielectric constant (/spl epsiv//sub /spl tau///spl sim/90) has been developed for embedded capacitor application. This polymer-ceramic system consists of lead magnesium niobate-lead titanate (PMN-PT) ceramic particle and modified high-dielectric constant low-viscosity epoxy resin. In order to obtain precise prediction of effective dielectric constant of this composite, an empirical prediction model based on self-consistent theory is proposed. The electrical polarization mechanism and interaction between epoxy resin and ceramic filler has been studied. This model can establish the relevant constitutional parameters of polymer-ceramic composite materials such as particle shape, composition, and connectivity that determine the dielectric properties of the composite. This model is simpler, uses fewer parameters and its prediction compares better with experiment (error <10%). The precision and simplicity of the model can be exploited for predictions of the properties and design of nanostructure ferroelectric polymer-ceramic composites. The effective-medium theory (EMT) has been proved a good tool to predict effective properties of nanocomposites.
Resistance is futile: but it is slowing the pace of EHR adoption nonetheless.

The purpose of this study is to reassess the projected rate of Electronic Health Record (EHR) diffusion and examine how the federal government's efforts to promote the use of EHR technology have influenced physicians' willingness to adopt such systems. The study recreates and extends the analyses conducted by Ford et al.1 The two periods examined come before and after the U.S. Federal Government's concerted activity to promote EHR adoption. Meta-analysis and bass modeling are used to compare EHR diffusion rates for two distinct periods of government activity. Very low levels of government activity to promote EHR diffusion marked the first period, before 2004. In 2004, the President of the United States called for a ?Universal EHR Adoption? by 2014 (10 yrs), creating the major wave of activity and increased awareness of how EHRs will impact physicians' practices. EHR adoption parameters—external and internal coefficients of influence—are estimated using bass diffusion models and future adoption rates are projected. Comparing the EHR adoption rates before and after 2004 (2001–2004 and 2001–2007 respectively) indicate the physicians' resistance to adoption has increased during the second period. Based on current levels of adoption, less than half the physicians working in small practices will have implemented an EHR by 2014 (47.3%). The external forces driving EHR diffusion have grown in importance since 2004 relative to physicians' internal motivation to adopt such systems. Several national forces are likely contributing to the slowing pace of EHR diffusion.
All-Optical Chromatic Dispersion Monitoring for Phase-Modulated Signals Utilizing Cross-Phase Modulation in a Highly Nonlinear Fiber

We propose and experimentally demonstrate an all-optical chromatic dispersion (CD) monitoring technique for phase-modulated signals utilizing the cross-phase-modulation effect between the input signal and the inserted continuous-wave probe. The probe's optical spectrum changes with the accumulated CD on the input signal, indicating that the optical power variations can be measured for monitoring. The experimental results show that this technique can monitor up to 120 ps/nm of CD for a 40-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) transmission system, with the maximum measured optical power increment of 16.5 dB. The applicability of this monitoring technique to higher bit-rate phase-modulated signals, such as 80-Gb/s RZ differential quadrature phase-shift keying and 80-Gb/s polarization-multiplexed RZ-DPSK, is also investigated via simulation.
Evaluating commonsense knowledge with a computer game

Collecting commonsense knowledge from freely available text can reduce the cost and effort of creating large knowledge bases. For the acquired knowledge to be useful, we must ensure that it is correct, and that it carries information about its relevance and about the context in which it can be considered commonsense. In this paper, we design, and evaluate an online game that classifies, using the input from players, text extracted from the web as either commonsense knowledge, domain-specific knowledge, or nonsense. A continuous scale is defined to classify the knowledge as nonsense or commonsense and it is later used during the evaluation of the data to identify which knowledge is reliable and which one needs further qualification. When comparing our results to other similar knowledge acquisition systems, our game performs better with respect to coverage, redundancy, and reliability of the commonsense acquired.
Representing Part-Whole Relationships in Recurrent Neural Networks

There is little consensus about the computational function of top-down synaptic connections in the visual system. Here we explore the hypothesis that top-down connections, like bottom-up connections, reflect part-whole relationships. We analyze a recurrent network with bidirectional synaptic interactions between a layer of neurons representing parts and a layer of neurons representing wholes. Within each layer, there is lateral inhibition. When the network detects a whole, it can rigorously enforce part-whole relationships by ignoring parts that do not belong. The network can complete the whole by filling in missing parts. The network can refuse to recognize a whole, if the activated parts do not conform to a stored part-whole relationship. Parameter regimes in which these behaviors happen are identified using the theory of permitted and forbidden sets [3, 4]. The network behaviors are illustrated by recreating Rumelhart and McClelland's "interactive activation" model [7].
A gene expression profile of stem cell pluripotentiality and differentiation is conserved across diverse solid and hematopoietic cancers.

Background: Understanding the fundamental mechanisms of tumorigenesis remains one of the most pressing problems in modern biology. To this end, stem-like cells with tumor-initiating potential have become a central focus in cancer research. While the cancer stem cell hypothesis presents a compelling model of self-renewal and partial differentiation, the relationship between tumor cells and normal stem cells remains unclear. Results: We identify, in an unbiased fashion, mRNA transcription patterns associated with pluripotent stem cells. Using this profile, we derive a quantitative measure of stem cell-like gene expression activity. We show how this 189 gene signature stratifies a variety of stem cell, malignant and normal tissue samples by their relative plasticity and state of differentiation within Concordia, a diverse gene expression database consisting of 3,209 Affymetrix HGU133+ 2.0 microarray assays. Further, the orthologous murine signature correctly orders a time course of differentiating embryonic mouse stem cells. Finally, we demonstrate how this stem-like signature serves as a proxy for tumor grade in a variety of solid tumors, including brain, breast, lung and colon. Conclusions: This core stemness gene expression signature represents a quantitative measure of stem cellassociated transcriptional activity. Broadly, the intensity of this signature correlates to the relative level of plasticity and differentiation across all of the human tissues analyzed. The fact that the intensity of this signature is also capable of differentiating histological grade for a variety of human malignancies suggests potential therapeutic and diagnostic implications.
Direct measurement of the meridional circulation in the stratosphere during the IGY

In this study the horizontal component of the meridional circulation at the 100, 50 and 30 mb levels in the stratosphere is computed for the IGY period July 1957 through June 1958. Radiosonde data from approximately 240 stations, well distributed over the northern hemisphere, are used in the analysis of the north-south component of the wind. Values of the mean meridional circulation for the four seasons are presented at every 5° latitude from the equator to 80°N.
Radiographic Outcomes Following Lateral Column Lengthening With a Porous Titanium Wedge

Background:Lateral column lengthening (LCL) is commonly utilized in treating stage II posterior tibialis tendon dysfunction. This study aimed to analyze the outcomes of LCL with porous titanium wed...
THE INFORMATIONAL REQUIREMENTS FOR EFFECTIVE REGULATORY REVIEW: AN ANALYSIS OF THE EPA LEAD STANDARD

The shortcomings of the EPA lead standard were largely determined by the requirements of the Clean Air Act. EPA's analysis was inadequate since the underlying risks were modelled in terms of critical thresholds irrespective of the particular probability of the adverse health outcome associated with the exposure. The informational requirements for meaningful review are compared with the actual benefit and cost data provided by EPA. The misplaced EPA approach prevented the generation of appropriate information on which to base a policy decision and hampered the subsequent review efforts by the White House oversight group. It is doubtful whether any oversight effort can be fully effective without a major change in the Clean Air Act.
Charge symmetry in pion-nucleus scattering

It is shown that a conventional Kisslinger model analysis of the 64.8 MeV ..pi..-/sup 40/Ca elastic scattering data of Dam et al. indicates that the optical model potentials are the same for ..pi../sup + -/. This is in disagreement with the earlier analysis of Dam et al. but in agreement with the requirements of charge symmetry.
Electrostatic surface drives: theoretical considerations and fabrication

Micromachined actuators with large travel, highly precise position control, and low actuation voltage are essential for atomic resolution storage, micro-optical stages, microwave devices, and control surfaces for a variety of sensors. We describe the characteristics and limitations of a novel electrostatic surface drive. A prototype, fabricated with two-level metallization, deep silicon etching, and a dry release process, has demonstrated 8 /spl mu/m travel at 4 V applied bias.
Contact mechanics description of inelastic displacement response of a nano-positioning device

A classical mechanistic model was developed to capture the existence of pre-sliding tangential deflection (PSTD) in contacting polysilicon and coated polysilicon surfaces. For the purposes of modeling asperity friction, experiments have shown, and been supported through detailed finite element analyses, that frictional forces developed through tangential sliding scale linearly through a material parameter known as the junction strength. A junction strength model coupled with a discrete quasi-static contact mechanics analysis, using contacting surface descriptions sampled by AFM from actual polysilicon surfaces, predicts inelastic tangential displacements that are qualitatively consistent with observed PSTD response. The simulations imply that the existence of PSTD depends not only on the spatial characteristics of contacting surfaces, but also on the local loading characteristics.
New drugs for treatment of attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is one of the longest recognised and most common neuropsychiatric disorders of childhood. Recent research indicates that ADHD is most often a lifelong condition associated with significant impairment in multiple domains of functioning. ADHD is a clinical diagnosis made on the basis of history and clinical examination. Current molecular, neuroimaging and neuropsychological studies have greatly elucidated our understanding of the basic science of ADHD. The underlying pathophysiology of ADHD has been theorised to be dysregulation of inhibitory noradrenergic frontocortical activity on dopaminergic striatal structures. Pharmacotherapy is recognised as the most effective component of ADHD treatment, although some role exists for proper educational placement, parent management training and social skills development. Methylphenidate and amphetamine are the current standards in ADHD medication treatment. Other medication classes such as tricyclic antidepressants and certain antihypertensives are also used in off-label therapy. Anticipated improvements in new ADHD medications include the development of extended release delivery systems, improved tolerability, alternative mechanisms of action and enhanced efficacy in treatment refractory cases.
California Wintertime Precipitation Bias in Regional and Global Climate Models

Abstract In this paper, wintertime precipitation from a variety of observational datasets, regional climate models (RCMs), and general circulation models (GCMs) is averaged over the state of California and compared. Several averaging methodologies are considered and all are found to give similar values when the model grid spacing is less than 3°. This suggests that California is a reasonable size for regional intercomparisons using modern GCMs. Results show that reanalysis-forced RCMs tend to significantly overpredict California precipitation. This appears to be due mainly to the overprediction of extreme events; RCM precipitation frequency is generally underpredicted. Overprediction is also reflected in wintertime precipitation variability, which tends to be too high for RCMs on both daily and interannual scales. Wintertime precipitation in most (but not all) GCMs is underestimated. This is in contrast to previous studies based on global blended gauge–satellite observations, which are shown here to under...
Studies on tRNA and aminoacyl-tRNA synthetases during the development of Rana pipiens.

Abstract Amphibian embryos at different developmental stages have been studied with respect to their aminoacyl-tRNA synthetases and tRNA. Synthetase preparations from each embryonic stage were active in aminoacylation of tRNA and showed properties similar to synthetases from other sources as judged by the ATP-PP i exchange and hydroxamate formation reactions. Transfer-RNA was quantitated in two ways: one by the total amount of A 260 material in the 4 S fraction of preparations from different developmental stages, and the other by measuring the amino acid acceptor activity of these same preparations aminoacylated with stage 25 synthetases. The two methods gave very different values for tRNA from early embryonic stages. Only a small part of the difference could be accounted for by the amount of inactive tRNA from early embryos. Preliminary experiments indicate that most of the difference noted was due to changes in the tRNA and synthetase pools during embryogenesis. Furthermore, it is suggested that two major groups of these macromolecules are present: one group appears predominate between ovulation and gastrulation, and the other gains dominance during subsequent development.
Targeting protein–protein interactions by rational design: mimicry of protein surfaces

Protein–protein interactions play key roles in a range of biological processes, and are therefore important targets for the design of novel therapeutics. Unlike in the design of enzyme active site inhibitors, the disruption of protein–protein interactions is far more challenging, due to such factors as the large interfacial areas involved and the relatively flat and featureless topologies of these surfaces. Nevertheless, in spite of such challenges, there has been considerable progress in recent years. In this review, we discuss this progress in the context of mimicry of protein surfaces: targeting protein–protein interactions by rational design.
Renewable resource management with environmental prediction

Variations in environmental conditions affect renewable resource growth. The ability to predict such variations is improving, providing scope for improved management. We generalize a common stochastic stock recruitment model to explore how optimal management changes with environmental prediction. We obtain three main results. First, while it might seem that a prediction of adverse future conditions should lead to more conservative management, the opposite may be true. Second, optimal management requires only a one-period-ahead forecast, suggesting forecast accuracy is more important than forecast lead time. Finally, we derive conditions on environmental fluctuations guaranteeing positive optimal harvest in every period. Gestion d'une ressource renouvelable quand on predit les conditions futures de l'environnement. Les variations dans les conditions de l'environnement affectent la croissance de la ressource renouvelable. La capacitea prevoir ces variations s'ameliore et ouvre la possibilite d'ameliorer la gestion de la ressource. Les auteurs utilisent un modele de ressource renouvelable avec croissance stochastique et obtiennent trois resultats. D'abord, alors qu'il peut sembler que des previsions pessimistes de conditions difficiles dans l'avenir peuvent conduire a une gestion plus conservatrice, le contraire peut etre vrai. Ensuite, la gestion optimale requiert seulement une prediction pour la prochaine periode: voila qui suggere qu'il est plus important d'avoir une prevision exacte que d'avoir des previsions a plus long terme. Enfin, on developpe les conditions pour les fluctuations de l'environnement qui garantissent une recolte positive optimale a chaque periode.
Human Evolution and Osteoporosis-Related Spinal Fractures

The field of evolutionary medicine examines the possibility that some diseases are the result of trade-offs made in human evolution. Spinal fractures are the most common osteoporosis-related fracture in humans, but are not observed in apes, even in cases of severe osteopenia. In humans, the development of osteoporosis is influenced by peak bone mass and strength in early adulthood as well as age-related bone loss. Here, we examine the structural differences in the vertebral bodies (the portion of the vertebra most commonly involved in osteoporosis-related fractures) between humans and apes before age-related bone loss occurs. Vertebrae from young adult humans and chimpanzees, gorillas, orangutans, and gibbons (T8 vertebrae, n = 8-14 per species, male and female, humans: 20-40 years of age) were examined to determine bone strength (using finite element models), bone morphology (external shape), and trabecular microarchitecture (micro-computed tomography). The vertebrae of young adult humans are not as strong as those from apes after accounting for body mass (p<0.01). Human vertebrae are larger in size (volume, cross-sectional area, height) than in apes with a similar body mass. Young adult human vertebrae have significantly lower trabecular bone volume fraction (0.26±0.04 in humans and 0.37±0.07 in apes, mean ± SD, p<0.01) and thinner vertebral shells than apes (after accounting for body mass, p<0.01). Since human vertebrae are more porous and weaker than those in apes in young adulthood (after accounting for bone mass), even modest amounts of age-related bone loss may lead to vertebral fracture in humans, while in apes, larger amounts of bone loss would be required before a vertebral fracture becomes likely. We present arguments that differences in vertebral bone size and shape associated with reduced bone strength in humans is linked to evolutionary adaptations associated with bipedalism.
Case Report of Unilateral Clefting: Is Sonic Hedgehog to Blame?

We describe the autopsy of a chromosomally normal multiple-anomaly fetus with left side-restricted malformations, terminated after routine screening ultrasound. Autopsy findings were remarkable for severe left-sided craniofacial malformations including a cleft left frontal calavarial bone and an oblique facial cleft. Internal examination showed multiple left-sided malformations including severe left ventricular hypoplasia and interrupted aortic arch. A hypoplastic left lung, an accessory spleen, and an absent left kidney and left ureter were also discovered. Some features of the Smith-Lemli-Opitz Syndrome (SLOS) are found in this fetus, yet the occurrence of left side-restricted anomalies indicates that developmental mechanisms responsible for body laterality are involved. Potential mechanisms leading to this constellation of anomalies include a ciliary defect, side-restricted chromosomal mosaicism, or a teratogenic insult, affecting developmental morphogens, including sonic hedgehog. The sonic hedgehog pathway is important in the molecular mechanisms underlying SLOS and in laterality development in the early embryo.
Viewing the 1996 FAF Restructuring as Policy Making without a Formal Due Process

In 1996, a major financial reporting controversy emerged, escalated, and was resolved without substantial exposure or a formal due process. Specifically, a committee of the Financial Executives Institute (FEI) sent a letter to the chair of the Financial Accounting Foundation (FAF) asserting that the Financial Accounting Standards Board (FASB) “process is broken and in need of substantive repair.” When Securities and Exchange Commission (SEC) Chair Arthur Levitt determined that neither FAF nor public accounting leaders were dealing with the FEI proposals to his satisfaction, he acted to defeat this perceived threat to FASB's independence, focusing on the composition of the FAF. In response, the FAF trustees resisted because they viewed his intervention as a threat to FASB's independence. When the trustees did not voluntarily change, Levitt proposed reconsidering Accounting Series Release No. 150, which designates FASB as the sole source of GAAP for SEC filings. Eventually, Levitt prevailed. This paper desc...
Recent Progress on Going-Down I

The years 1970–77 witnessed considerable research activity in connection with the “going-down” concept. To chronicle that activity and the sub­ject’s earlier history, Ira Papick and I wrote a survey [78] which appeared in 1978. Since then, work in this area has continued unabated, and I propose to survey most of the post-1977 work concerning “going-down.” Because of limitations of space, our focus here is almost exclusively on papers of which I was either the author or a coauthor. In doing so, I take this opportunity to thank my 24 coauthors whose work is referenced here, while begging the indulgence of the few authors whose post-1977 work on “going-down” goes unmentioned here.
Are Mutual Fund Investors Bayesian Learners

Many financial models assume that financial market participants learn following Bayes’ rule. In this paper, we use a new measure of investor disagreement to study the learning speed of mutual fund investors about manager skill. Although the precision of estimates of manager skill increases quickly over time, investors’ disagreement about manager skill does not decline for many years. Investors’ non-Bayesian learning is not due to the inconsistency of potential performance measures used by investors, or investing frictions, but is likely due to limited attention. Overall, our results suggest market participants learn much more slowly than currently assumed.
Chart-based strategies for solving Bayesian inference problems

This research examines problem-solving strategies students use to understand probabilistic inference. A qualitative analysis of one-on-one interviews with two undergraduate students was conducted to identify specific methods these students used to understand and solve Bayesian inference problems. The participants' use of chart-based methods helped them identify relevant information in the problem. From these interviews it seems that this disconnect between the text of a problem and an algebraic formula may indicate difficulties some students have with other mathematical concepts, including probabilistic dependence.
Benefits of Coherent Low-IF for Vital Signs Monitoring Using Doppler Radar

Homodyne receiver systems have been used extensively in wireless life signs monitoring applications. The main advantage of a homodyne system is range correlation resulting in cancellation of the oscillator phase noise. However, direct down-conversion to dc and the subsequent baseband amplification circuit will introduce additional flicker noise to the signal. Physiological signals have significant content around dc that will make them susceptible to 1/f noise. A coherent low-IF system is applied to solve this problem. This architecture has the range correlation benefits of the homodyne system, while minimizing the baseband flicker noise. Measurements on a mechanical target and a human subject demonstrate a signal-to-noise ratio improvement of 7 dB, which can increase the range of operation by 50%. Measurements on a human subject have demonstrated low-IF heart rate detection with a root-mean-square error of less than 0.8 beats/min at a distance of almost 3 m with transmit power of 0.1 mW, whereas direct conversion architecture output completely failed in this case.
Izucaris Masudai, New Genus, New Species (Decapoda: Caridea: Palaemonidae), a Sea Anemone Associate From Japan

ABSTRACT A new genus is proposed for Izucaris masudai, new species, a pontoniid shrimp associated with the sea anemone Nemanthus nitidus. Izucaris, new genus, is closely related to the genus Pontonides sensu stricto, but distinguished by the rostrum overreaching the midlength level of the distal peduncular article of the antennule, the pterygostomian margin distinctly tapering anteriorly, and the lack of a distinct protrusion on the medial margin of the dactyl of the second maxilliped. The type species is described and illustrated based on a male and a female collected from Izu Peninsula, Honshu, Japan. The color pattern of the new species may show a chromatic adaptation.
19 EVIDENCE OF OXIDATIVE STRESS IN A RAT MODEL OF PREECLAMPSIA.

We have developed a rat model of preeclampsia related to the administration to pregnant animals of desoxycorticosterone acetate (DOCA) and the replacement of their drinking water with 0.9% saline. At 16-19 days of gestation, the rats demonstrate established hypertension, proteinuria, and intrauterine growth restriction (IUGR). Oxidative stress has been reported in various hypertensive models and is considered to play an important role in the pathogenesis of some of the clinical features of preeclampsia. Accordingly, we have studied the urinary excretion of 8-isoprostane (8-IP), an indicator of the oxidative process. Pregnant Sprague-Dawley rats (250-300 g) were rendered “preeclamptic” (PDS, n = 7). Determinations were performed prior to pregnancy and at 16-19 days of gestation. Their blood pressures (BPs), 24-hour protein, and 8-IP excretion in urine and pup numbers for PDS rats were compared to those of normal pregnant animals (NP, n = 6). BP, obtained with a tail cuff method, increased in the PDS rats from a baseline level of 114 ± 3 to 136 ± 2 mm Hg (p .05) from prepregnancy to late gestation periods (6.6 ± 0.6 and 9.3 ± 1.3 pg/min, respectively). Based upon these data, we conclude that oxidative stress is a feature of a rat model of preeclampsia as it is in the human condition.
Selective, tunable O2 binding in cobalt(II)–triazolate/pyrazolate metal–organic frameworks

The air-free reaction of CoCl2 with 1,3,5-tri(1H-1,2,3-triazol-5-yl)benzene (H3BTTri) in N,N-dimethylformamide (DMF) and methanol leads to the formation of Co-BTTri (Co3[(Co4Cl)3(BTTri)8]2·DMF), a sodalite-type metal-organic framework. Desolvation of this material generates coordinatively unsaturated low-spin cobalt(II) centers that exhibit a strong preference for binding O2 over N2, with isosteric heats of adsorption (Qst) of -34(1) and -12(1) kJ/mol, respectively. The low-spin (S = 1/2) electronic configuration of the metal centers in the desolvated framework is supported by structural, magnetic susceptibility, and computational studies. A single-crystal X-ray structure determination reveals that O2 binds end-on to each framework cobalt center in a 1:1 ratio with a Co-O2 bond distance of 1.973(6) A. Replacement of one of the triazolate linkers with a more electron-donating pyrazolate group leads to the isostructural framework Co-BDTriP (Co3[(Co4Cl)3(BDTriP)8]2·DMF; H3BDTriP = 5,5'-(5-(1H-pyrazol-4-yl)-1,3-phenylene)bis(1H-1,2,3-triazole)), which demonstrates markedly higher yet still fully reversible O2 affinities (Qst = -47(1) kJ/mol at low loadings). Electronic structure calculations suggest that the O2 adducts in Co-BTTri are best described as cobalt(II)-dioxygen species with partial electron transfer, while the stronger binding sites in Co-BDTriP form cobalt(III)-superoxo moieties. The stability, selectivity, and high O2 adsorption capacity of these materials render them promising new adsorbents for air separation processes.
Generation and function of osteocyte dendritic processes.

Osteocytes in vivo possess a distinctive morphology – that of dendricity – connecting osteocyte to osteocyte creating the osteocyte syncytium and also connecting osteocytes with cells on the bone surface (see Figure 1). It is thought that bone fluid surrounding the dendrite within the canaliculi is responsible for the transmission of mechanical strain through fluid flow shear stress. Dendrites may be essential for osteocyte function, viability, and response to load. The cell processes of osteocytes are connected with each other via gap junctions, thereby allowing direct cell-to-cell coupling. Osteocytes and MLO-Y4 osteocyte-like cells express large amounts of Connexin 43, the component of gap junctions. But as these cells are only in contact through the tips of their dendritic processes, this raises the question, what is the function of Cx 43 located on the rest of the cell membrane? Recently it has been shown that connexins can complex and function in the form of un-apposed halves of gap junction channels called hemichannels. These channels are localized at the cell surface, independent of physical contact with adjacent cells. Recently evidence of functional hemichannels formed by Cx43 has been reported in neural progenitors and neurons, astrocytes, heart, and especially, osteoblasts and osteocytes. The opening of hemichannels appears to provide a mechanism for ATP and NAD release, which raises intracellular Ca levels and promotes Ca wave propagation in astrocytes, bone cells, epithelial cells, and outer retina. Hemichannels expressed in bone cells such as MLO-Y4 cells appear to function as essential transducers of the anti-apoptotic effects of bisphosphonates and act as a portal for the extracellular release of PGE2 in osteocytes upon exposure to fluid flow shear stress. Therefore, in osteocytes, gap junctions at the tip of dendrites appear to mediate a form of intracellular communication and J Musculoskelet Neuronal Interact 2005; 5(4):321-324
A First Upper Bound

Let a > 0, b, A > 0, B be integers for which $$\Delta = \det (\begin{array}{*{20}{c}} a&b \\ A&B \end{array}) \ne 0.$$