cssi/SciSciGPT-SciSciNet huggingface dataset:
A budding yeast's perspective on aging: The shape I'm in

Aging is exemplified by progressive, deleterious changes that increase the probability of death. However, while the effects of age are easy to recognize, identification of the processes involved has proved to be much more difficult. Somewhat surprisingly, research using the budding yeast has had a profound impact on our current understanding of the mechanisms involved in aging. Herein, we examine the biological significance and implications surrounding the observation that genetic pathways involved in the modulation of aging and the determination of lifespan in yeast are highly complicated and conserved.
Spatially multiplexed multi-input-multi-output optical imaging system in a turbid, turbulent atmosphere

Active optical imaging is preferred over radio frequency counterparts due to its higher resolution, faster area search rate, and relatively easier learning and interpretation of the image by a human observer. However, in imaging through atmosphere, one should consider dispersive effects of multiple scatterings and turbulence-induced wave perturbations, which give rise to intensity fluctuations and wavefront distortions. All these phenomena broaden and distort the spatial impulse response known as the point spread function (PSF). In this paper, a spatially multiplexed multi-input-multi-output imaging system design, inspired by multispot diffuse indoor communications configuration first introduced by Yun and Kavehrad [IEEE International Conference Selected Topics in Wireless Communications (IEEE, 1992), pp 262-265], is presented. At the transmitter, a computer-generated holographic beam splitter is used to generate arrays of beamlets, providing a faster area search rate and a uniformly distributed illumination over the entire target area. Then, at the receiver, an array of photodetectors is used to collect the reflected rays. While a Monte Carlo ray-tracing algorithm developed at Pennsylvania State University, Center for Information and Communications Research (CICTR), is used to model imaging in multiple-scattering turbid media, phase screens are employed to simulate turbulence-induced wavefront distortions. Hence, a comprehensive framework is exploited that takes into account possible sources of degradation. Using this framework, system performance is analyzed under different meteorological conditions. Restoration techniques such as adaptive-optics corrections, blind deconvolution, and time gating are used to improve the contrast and enhance the sharpness and resolution of the images.
An Integral Method for Turbulent Boundary Layers on Rotating Disks

An integral method for computing turbulent boundary layers on rotating disks has been developed using a power law profile for the tangential velocity and a new model for the radial profile. A similarily solution results from the formulation. Radical transport, boundary layer growth, and drag on the disk were computed for the case of a forced vortex freestream flow. The results were compared to previous similarity solutions. The method was extended to a Rankine vortex freestream flow. Differential equations for boundary layer parameters were developed and solved for different Reynolds numbers to look at the net entrainment, boundary layer growth, and drag on the disk
Blood groups of Baboons. Population genetics of feral animals.

Blood and saliva from 495 Ethiopan baboons were collected in the field and tested for their human-type A-B-O groups while 493 blood samples were tested for their simian-type blood factors Ap, Bp, Cp, Gp, Np, ca and hu. Four series of feral animals were tested: 194 olive baboons, a troop of 82 and another of 90 hamadryas baboons, and a series of 129 baboons classified as olive/hamadryas hybrids. In addition, 126 baboons from other sources were tested for their human-type A-B-O groups and 131 for their simian-type blood groups. Human-type groups A, B and AB but not group O were found in combined series of 621 animals. Gene frequency analysis also indicated the absence of group O. Population analysis of the data obtained for the 493 Ethiopian baboons has shown that the simian-type blood groups Ap and Bp are independent of one another. In contrast Bp and Gp appear to be determined by corresponding allelic genes; if confirmed by population data on additional series of animals, this would define the first baboon blood group system found. There is a close association between the blood group specificities ca and hu, the exact nature of which still remains to be clarified. Blood group ca, originally believed to be species specific, is found to be polymorphic in both olive baboons and hamadryas as well as in the hybrids; hu, on the other hand, present in all hamadryas tested, is polymorphic only in olive baboons.
Response rate of bone mineral density to teriparatide in postmenopausal women with osteoporosis

Purpose: It is desirable for clinicians to know what bone mineral density (BMD) response they can expect in women treated with osteoporosis therapies. The focus of this analysis was to determine what percentage of women attained a lumbar spine BMD response to teriparatide that equaled or exceeded the least significant change (LSC) value of 3%. Methods: Data from three clinical trials involving postmenopausal women with osteoporosis were examined. The Fracture Prevention Trial was a double-blinded, placebo-controlled clinical trial examining the safety and efficacy of teriparatide 20 and 40 μg/day. The other two trials were double-blinded, head-to-head comparisons of alendronate 10 mg/day and teriparatide 20 or 40 μg/day, respectively. Only treatment-compliant women who had lumbar spine BMD measurements at all specified time points in these trials were included. For reference, we also examined the percentage of women with lumbar spine BMD responses to alendronate. Hip BMD responses that equaled or exceeded 3% were also examined. Results: According to the LSC criteria, 91% of the teriparatide 20 μg/day group and 94% of the teriparatide 40 μg/day group were lumbar spine BMD responders at 18 months in the Fracture Prevention Trial. In the teriparatide 20 μg/alendronate head-to-head trial, 94% of women receiving teriparatide had a lumbar spine BMD response that equaled or exceeded the 3% criterion at 18 months compared to 75% of those receiving alendronate 10 mg/day (p<0.01). In the teriparatide 40 μg/day group of the other head-to-head trial, 92% of women achieved the 3% criterion for the lumbar spine at 12 months compared to 69% of those receiving alendronate 10 mg/day (p<0.01). The median 3-month change in aminoterminal extension peptide of procollagen type 1 [PINP] in women who had a lumbar spine BMD response to teriparatide at 18 months was larger than in women who did not have a lumbar spine BMD response. However, the median 3-month PINP change in lumbar spine BMD nonresponders still exceeded the LSC value of 10 μg/L. Although the percentage of teriparatide-treated women with a hip BMD response that met the 3% criterion was significantly greater than for placebo, there was no significant difference between the percentage of teriparatide 20 μg/day and alendronate 10 mg/day responders in the comparison trial. The baseline characteristics of teriparatide lumbar spine responders and nonresponders were similar. Conclusion: This analysis demonstrates that the vast majority of treatment-compliant postmenopausal women with osteoporosis and minimal prior bisphosphonate exposure have a lumbar spine BMD response to teriparatide that meets or exceeds the LSC. The characteristics of teriparatide responders and nonresponders were not significantly different; thus, we were unable to discern any characteristics that could be used to identify potential nonresponders.
Recombinant Human Cytokines Stimulate Neutrophil Adherence to IgG Autoantibody-Treated Epithelial Basement Membranes

We investigated the ability of the purified recombinant human cytokines: tumor necrosis factor-alpha (rTNF), granulocyte-macrophage colony-stimulating factor (rGM-CSF), interleukin-1 beta (rlL-1), interleukin-3, and tumor necrosis factor-beta (rTNF-beta) to stimulate neutrophil adherence (NA) to basement membranes (BMs) of stratified squamous epithelia pretreated with autoantibodies (ABM) specific for the BM matrix protein, type-VII collagen. rTNF, rGM-CSF, rIL- 1, and rTNF-beta, but not IL-3, stimulated NA and stimulation was ABM- and cytokine-concentration-dependent. Stimulation was cytokine-specific and not due to endotoxin since it was significantly inhibited by cytokine-specific antibodies but not by polymyxin B (PB). rTNF and rGM-CSF were the most potent stimulators, were effective at concentrations 600%. Relative potency was: rTNF = rGM-CSF > rTNF-beta> rIL-1. Stimulation by rTNF was due to a rapid, time-dependent effect on the neutrophil, and NA appeared to be dependent, in part, on the low-affinity neutrophil receptor for lgG, Fc(gamma)RIII, because it could be specifically inhibited by monoclonal antibody (3G8) to Fc(gamma)RIII. These results suggest that rTNF, rGM-CSF, rIL-1, and rTNF-beta may contribute individually or in combination to immune-mediated inflammation and tissue injury by stimulating immune adherence of neutrophils to tissue-bound autoantibodies and immune complexes.
Processing and Characterization of Carbon Fiber/Epoxy Composites Reinforced With Graphite Nanoplatelets

The epoxy matrix in carbon fiber/epoxy composites was modified with graphite nanoplatelets to improve the matrix dominated mechanical properties of the composite. A prepreg-autoclave process was developed for preparation of nanoparticle-reinforced fiber composites. The in-plane shear modulus and longitudinal compressive strength were enhanced. The compressive strength of the composite was increased by 43% and 44%, and the in-plane shear modulus was improved by 7% and 15% for 3 wt% and 5 wt% of nanoparticle loadings, respectively. This mechanical enhancement is mainly attributed to the reinforcement of matrix phase by the nanoparticles. However, the substantially improved compressive strength is attributed in large part to the reduced waviness of the fibers in the uni-weave perform caused by the nanoparticles between layers.© 2007 ASME
Prolonging patency--choosing coronary bypass grafts.

The benefits of coronary bypass surgery last only as long as the grafts continue to function, notes Dr. Bruce W. Lytle. He discusses the important differences among coronary bypass grafts.
Development of a Model to Estimate 24‐Hour Urinary Creatinine Excretion

The accuracy of the spot urine analyte/creatinine ratio in estimating 24-hour excretion of the analyte is compromised because it is not adjusted for 24-hour creatinine excretion. The authors developed a model for conveniently estimating 24-hour creatinine excretion. The model was derived from 24-hour urine collections using multiple linear regression, including sex, weight, race, and age. The model was then evaluated in a validation cohort, assessing the correlation between estimated and measured 24-hour creatinine excretion and by comparing their correlation with muscle mass. Estimated creatinine excretion correlated strongly with measured creatinine excretion (r=0.80 in the entire cohort and 0.93 after eliminating patients with incomplete collections), and correlated at least as strongly as measured creatinine excretion with lean muscle mass (r=0.94 vs r=0.82, respectively). Adjusting spot urine analyte/creatinine ratios using the estimated 24-hour creatinine excretion by this convenient method can improve the accuracy of estimating 24-hour excretion of albumin, sodium, and other analytes.
Partial splenectomy with CO2 laser: An experimental study

A freehand carbon dioxide laser is now available for surgical procedures. A comparison of its utility with the electrocautery was carried out in five dogs by the performance of hemisplenectomy. All dogs survived without complications. The laser proved to be an effective instrument for partial splenectomy under the terms of the experiment.
Kinetic model of the effects of electrogenic enzymes on the membrane potential

Electrogenic enzymes contribute to the electrical field existing across biological membranes by using a source of free energy to generate an ionic current. The model introduced here permits one to evaluate this contribution. Since the model incorporates the electrogenic enzyme in the form of a sequential kinetic diagram, it permits one to study the kinetic effects of the concentration of the enzyme, the substrates and the different ligands on the membrane potential. Ionic electrodiffusion is expressed in terms of a chemical reaction; ionic permeabilities are thus treated as voltage-dependent rate constants. We use the condition of global electroneutrality to obtain an expression for the electrical potential difference across the membrane; such expression constitutes an extension of the Goldman-Hodgkin-Katz equation. The enzyme-related terms appear in the equation as functions of the rate constants and the diverse concentrations. The model is used to analyze the case of a cell membrane traversed by Na+ and K+ by simple diffusion, and by electrogenic transport mediated by a Na+-K+ ATPase. The enzyme reaction is represented by the six-step scheme proposed by Chapman et al. (1983, J. membr. Biol. 74, 139–153). The main results of the numerical calculations are that, within a certain interval, the membrane potential difference depends linearly on the enzyme density and hyperbolically on the ATP concentration. A similar behavior has been experimentally observed for the electrogenic proton pump of Neurospora crassa. Thus, the model here can be useful in the explanation and prediction of effects of electrogenic enzymes on the membrane potential.
Diffuse Infiltrative Hepatocellular Carcinoma: Assessment of Presentation, Treatment, and Outcomes

Background Data on infiltrating hepatocellular carcinoma (HCC) are limited. We sought to define treatment and outcome of patients treated with infiltrating HCC compared with patients who had advanced multifocal HCC.
Report Calls for Balancing Energy Security, Energy Equity, and Environmental Concerns

Balancing the sometimes conflicting needs for energy security, energy equity, and environmental sustainability—including trying to limit average global temperature increases—can be a daunting task for countries. A new report focuses on the challenges and potential pathways to achieving this energy “trilemma” of meeting energy and environmental needs.
Free air carbon dioxide enrichment: development, progress, results

Credible predictions of climate change depend in part on predictions of future CO2 concentrations in the atmosphere. Terrestrial plants are a large sink for atmospheric CO2 and the sink rate is influenced by the atmospheric CO2 concentration. Reliable field experiments are needed to evaluate how terrestrial plants will adjust to increasing CO2 and thereby influence the rate of change of atmospheric CO2. Brookhaven National Laboratory (BNL) has developed a unique Free-Air CO2 Enrichment (FACE) system for a cooperative research program sponsored by the U.S. Department of Energy and U.S. Department of Agriculture, currently operating as the FACE User Facility at the Maricopa Agricultural Center (MAC) of the University of Arizona. The BNL FACE system is a tool for studying the effects of CO2 enrichment on vegetation and natural ecosystems, and the exchange of carbon between the biosphere and the atmosphere, in open-air settings without any containment. The FACE system provides stable control of CO2 at 550 ppm ± 10%, based on 1-min averages, over 90% of the time. In 1990, this level of control was achieved over an area as large as 380 m2, at an annual operating cost of $668 m−2. During two field seasons of enrichment with cotton (Gossypium hirsutum) as the test plant, enrichment to 550 ppm CO2 resulted in significant increases in photosynthesis and biomass of leaves, stems and roots, reduced evapotranspiration, and changes in root morphology. In addition, soil respiration increased and evapotranspiration decreased.
The History of Multiphase Computational Fluid Dynamics

Advertisements Larger Cover June 2, 2010 Volume 49, Issue 11 Pages 5027-5488 GIDASPOW ISSUE EDITORIAL COMMENTARY KINETICS, CATALYSIS, AND REACTION ENGINEERING PROCESS DESIGN AND CONTROL SEPARATIONS GENERAL RESEARCH REVIEWS APPLIED CHEMISTRY KINETICS, CATALYSIS, AND REACTION ENGINEERING MATERIALS AND INTERFACES PROCESS DESIGN AND CONTROL SEPARATIONS GENERAL RESEARCH RESEARCH NOTES In this issue: Table of
Lack of influence of vitamin D deficiency on insulin release from the isolated pancreatic islets of rats.

Pancreatic islets were isolated from young (100 g) and adult (390 g), normal and vitamin D deficient male Sprague-Dawley rats. The release of insulin from leucine-stimulated or glucose-stimulated islet was not altered by vitamin D deficiency. The in vitro addition of either 25-hydroxy-or 1,25-dihydroxyvitamin-D had no effect on insulin release from either normal or vitamin D deficient islets. We conclude that the earlier report (Normal et al., Science209 (1980) 823–825) on vitamin D deficiency depressing insulin secretion from the perfused pancreas must be related to the vitamin's effect on insulin synthesis and not the islet's release of insulin.
A Neutral-Beam Injector for the Tandem-Mirror Fusion Reactor Delivering 147 MW of 1.2-MeV D°

A conceptual design of a high-current, 1.2-MeV Do injector is presented. This injector has an anticipated operating efficiency of 73%. Major advances in beam technology are needed to meet these specifications, including a continuous source of negative ions, an efficient electron-stripping cell, and the development of associated power conditioning and control equipment. All components in the proposed beam line are elaborations of physics experiments already reported in the literature; therefore, it should be possible to satisfy the neutral-beam requirements of the tandem-mirror reactor (TMR) in the not too distant future.
Interaction of Nonionic Hydrophilic Polymers with Phenols II: Interaction of Phenol and Hydroxyphenols with Certain Polyethylene Glycols

The general nature of the interaction between phenol and PEG was investigated utilizing equilibrium dialysis through a cellophane membrane and NMR analysis of the insoluble complexes. Equilibrium dialysis experiments indicated that there was no correlation between the binding of phenols and the increase in acidity associated with the addition of hydroxyl groups on the phenol nucleus. An increase in temperature was found to decrease the degree of binding of phenol with PEG. NMR data indicated that for high molecular weight PEG's complexed with phenol and p -chlorophenol, the insoluble, oily complexes contained two ETO base moles to each cosolute molecule.
Latent energy of deformation of amorphous polymers: 2. Thermomechanical and dynamic mechanical properties

Abstract Thermomechanical and dynamic mechanical measurements were made on some common amorphous polymers which had been deformed in uniaxial tension below their glass transition temperatures ( T g ). Stress-temperature experiments showed that a stress increase began just above the draw temperature for constrained samples which had been uniaxially predrawn. Similarly, unconstrained samples heated above the deformation temperature shrank in the draw direction. Dynamic mechanical experiments demonstrated the appearance of a relaxation below T g which disappeared upon annealing for the drawn samples. This behaviour was attributed to a partial release of energy stored during deformation. A qualitative explanation of the energy storage mechanism is proposed.
Effect of the sampling rate of the tracking system on free-space laser communications

Lasers play an ever-increasing role in aerospace communication systems by providing the most logical connectivity channels. They drive the advancements in modern optoelectronics; however, successful implementation of this technology hinges on having an equally advanced beam-steering system for tracking the communication counterpart in the presence of complex maneuvers and the resident vibration of the airframe. The work presented in this paper concentrates on the development of agile acousto-optic beam-steering systems for laser communication terminals, which use constant-gain controllers augmented with an adaptive Kalman filter. Experimental results are presented to demonstrate communication performance as a function of the sampling rate in the tracking loop.
Maxadilan activates PAC1 receptors expressed in Xenopus laevis melanophores

Functional interactions between ligands and their cognate receptors can be investigated using the ability of melanophores from Xenopus laevis to disperse or aggregate their pigment granules in response to alterations in the intracellular levels of second messengers. We have examined the response of long-term lines of cultured melanophores from X. laevis to pituitary adenylate cyclase activating peptide (PACAP), a neuropeptide with vasodilatory activity, and maxadilan, a vasodilatory peptide present in the salivary gland extracts of the blood feeding sand fly. Pituitary adenylate cyclase activating peptide increased the intracellular levels of cyclic adenosine monophosphate (cAMP) and induced pigment dispersion in the pigment cells, confirming that melanophores express an endogenous PACAP receptor. Maxadilan did not induce a response in non-transfected melanophores. When the melanophores were transfected with complementary DNA (cDNA) from the three different members of the PACAP receptor family, maxadilan induced pigment dispersion specifically and cAMP accumulation in melanophores transfected with the cDNA for PAC1 receptors but not VPAC1 or VPAC2 receptors. A melanophore line was generated that stably expresses the PAC1 receptor.
Self-determination: The tyranny of freedom.

Americans now live in a time and a place in which freedom and autonomy are valued above all else and in which expanded opportunities for self-determination are regarded as a sign of the psychological well-being of individuals and the moral well-being of the culture. This article argues that freedom, autonomy, and self-determination can become excessive, and that when that happens, freedom can be experienced as a kind of tyranny. The article further argues that unduly influenced by the ideology of economics and rational-choice theory, modern American society has created an excess of freedom, with resulting increases in people's dissatisfaction with their lives and in clinical depression. One significant task for a future psychology of optimal functioning is to deemphasize individual freedom and to determine which cultural constraints are necessary for people to live meaningful and satisfying lives.
Pay for performance: survey of diagnostic radiology faculty and trainees.

Purpose Pay-for-performance (P4P) programs have been implemented in many health care markets in the United States. The purpose of this study was to survey faculty members and trainees regarding familiarity with the P4P model and their interest in further education. Methods An eight-question survey designed to explore faculty member and trainee awareness of and attitudes toward P4P was distributed. Data were analyzed using Microsoft Excel. Results One hundred four of 144 questionnaires distributed to faculty members (50 of 70) and trainees (54 of 74) were returned. Sixty-one percent of trainees stated that they had never heard of the P4P model. Seventeen percent of trainees and 26% of attending radiologists were aware that P4P programs have already been instituted. Although 74% of trainees agreed that P4P will influence their reimbursement in the future, only 42% of attending radiologists agreed. A minority of trainees and attending radiologists (35%) felt that P4P improves the quality of care, whereas 42% were neutral. A majority were interested in further education. Conclusion Faculty members and trainees in diagnostic radiology in a university-based program were unfamiliar with the P4P model of reimbursement and were interested in learning more. Additional investigation is needed to ascertain whether this knowledge gap is widespread. This could influence future education about P4P on a national level.
The humanist moment

In “The Humanist Moment,” Chris Higgins sets out to recover a tenable, living humanism, rejecting both the version vilified by the anti-humanists and the one sentimentalized by the reactionary nostalgists. Rescuing humanism from such polemics is only the first step, as we find at least nine rival, contemporary definitions of humanism. Which movement or theory is the real humanism? Higgins contends that we can reconstruct a critical, dialectical humanism from the very tensions in these conceptions. On this view, humanism is neither a theory nor a movement, but a moment, a specific intervention evincing characteristic sensibilities, enabling us to navigate through one of a number of recurring dead spots in the life of culture. Higgins outlines four ongoing human dialectics whose vibrant center the humanist helps us regain: genuine hope/acceptance in the face of both fantasy and cynicism; combined awareness of our connectedness and distinctiveness rejecting both dogmatic universalizing and particularizing discourses; and humane learning as distant from scholasticism as it is from anti-intellectualism. An entire section is devoted to the fourth dialectic, showing how humanism has appeared as a corrective both to historicism and to presentism, helping us reconnect with the untimely, living voice of tradition.
Accentuating the Negative: The Mismatch Between Public Perception of Child Well-being and Official Statistics

This paper reports findings from a series of polls designed to ascertain how well the American public understands the circumstances, characteristics, and living conditions of American children. We compare poll responses to official statistics to assess the accuracy of the public’s perceptions. With few exceptions, the results suggest a large gap between the public’s perception of children and official statistics and highlight a second finding—primarily, where misperceptions exist the public tends to perceive children’s circumstances to be worse than they actually are. Bivariate and multivariate analyses indicate that there are small but significant group differences by education, gender, age and community type in the public’s understanding of child well-being. Our results also suggest that perceptions of children may be shaped in part by an individual’s environment and personal experiences. Possible contributors to this public gap in knowledge, implications for the dissemination of statistical information on children, and public policy are discussed.
Mutagenic potency and specificity of procarbazine in the ad-3 forward-mutation test in growing cultures of heterokaryon 12 of Neurospora crassa.

Abstract Procarbazine (Natulan®) was tested for its mutagenic potency and specificity in the ad-3 forward-mutation test in heterokaryon 12 (H-12) of Neurospora crassa . In these experiments, procarbazine was a weak mutagen when present in growing cultures but nonmutagenic when conidial suspensions (nongrowing conidia) were treated. A total of 208 ad-3 mutants recovered after exposure of growing cultures of H-12 to 1 mg of procarbazine/ml, and 2 ad-3 mutants of spontaneous origin, were characterized genetically. These tests distinguish among gene/point mutations ( ad-3 R ) at the ad-3A or ad-3B locus, multilocus deletion mutations ([ ad-3 ] IR ) covering one or more loci in the ad-3 and immediately adjacent regions, and 3 different classes of multiple-locus mutations: gene/point ad-3 mutations with a recessive lethal mutation elsewhere in the genome ( ad-3 R + RL ), gene/point mutations with a closely linked recessive lethal mutation ( ad-3 R + RL CL ), and multilocus deletion mutations with a closely linked recessive lethal mutation ([ ad-3 ] IR + RL CL ). All of the procarbazine-induced ad-3 mutants resulted from gene/point mutations; 92.2% ( 200 217 ) resulted from gene/point mutations at the ad-3A or ad-3B locus, and 3.7% ( 8 217 ) resulted from gene/point mutations with a recessive lethal mutation elsewhere in the genome. Identical percentages (15.4% [ 20 130 ] and 15.4% [ 12 78 ]) of the Σad-3B R and Σad-3A R mutants were leaky, and a high percentage (71.5% [ 93 130 ]) of the Σad-3B R mutants had nonpolarized complementation patterns. These results indicate that procarbazine-induced ad-3 mutants of Neurospora crassa are composed solely of gene/point mutations ( ad-3 R ) that resulted, predominantly or exclusively, from base-pair substitutions. The Neurospora specific-locus data on procarbazine-induced ad-3 mutants are compared with data from similar experiments with the mouse using the morphological specific-locus assay; marked similarities were found between the mutagenic effects of procarbazine in the 2 specific-locus assays.
Kinetic Mechanism for Single stranded DNA binding and Translocation by S. cerevisiae Isw2

The chromatin remodeling complex Isw2 from S. cerevisiae (yIsw2) mobilizes nucleosomes through an ATP-dependent reaction that is coupled to the translocation of the enzyme along intranucleosomal DNA. In this study we demonstrate that yIsw2 is capable of translocating along single-stranded DNA in a reaction that is coupled to ATP hydrolysis. We find that single-stranded DNA translocation by yIsw2 occurs through a series of repeating uniform steps with an overall macroscopic processivity of P = (0.92 ± 0.01); this processivity corresponds to an average translocation distance of (24 ± 4) nucleotides before dissociation. This processivity corresponds well to the processivity of nucleosome sliding by yIsw2 thus arguing that single-stranded DNA translocation may be fundamental to the double-stranded DNA translocation required for effective nucleosome mobilization by the enzyme. Furthermore, we find that a slow initiation process, following DNA binding, is required to make yIsw2 competent for DNA translocation. We also provide both evidence that this slow initiation process likely corresponds to the second step of a two-step DNA binding mechanism by yIsw2 and a quantitative description of the kinetics of this DNA binding mechanism.
Case Studies, Controversy and the ‘Fieldworker's Regress’

Amanda Rees, The Infanticide Controversy: Primatology and the Art of Field Science. Chicago and London: University of Chicago Press, 2009. ix + 288 pp. $40.00/£27.50. ISBN: 0-226-70711-3. Reviewed ...
Terminal state dynamic programming: Quadratic costs, linear differential equations

with y constrained to some class of admissible controls, Y. In this paper we wish to discuss a specialization of (l), a terminal control problem, in which the cost of state is measured only at the terminal time, T. We further assume that p and q are homogeneous quadratic functions of their arguments, that the state equation (2) is linear, and that there are no constraints on the control vector y. We thus arrive at the following terminal control problem:
An absolute requirement for Pax7-positive satellite cells in acute injury-induced skeletal muscle regeneration

Skeletal muscle tissue provides mechanical force for locomotion of all vertebrate animals. It is prone to damage from acute physical trauma and physiological stress. To cope with this, it possesses a tremendous capacity for rapid and effective repair that is widely held to be accomplished by the satellite cells lying between the muscle fiber plasmalemma and the basement membrane. Cell transplantation and lineage-tracing studies have demonstrated that Pax7-expressing (Pax7+) satellite cells can repair damaged muscle tissue repeatedly after several bouts of acute injury. These findings provided evidence that Pax7+ cells are muscle stem cells. However, stem cells from a variety of other origins are also reported to contribute to myofibers upon engraftment into muscles, questioning whether satellite cells are the only stem cell source for muscle regeneration. Here, we have engineered genetic ablation of Pax7+ cells to test whether there is any significant contribution to muscle regeneration after acute injury from cells other than this source. We find that such elimination of Pax7+ cells completely blocks regenerative myogenesis either following injury to the tibialis anterior (TA) muscle or after transplantation of extensor digitorum longus (EDL) muscles into nude mice. As Pax7 is specifically expressed in satellite cells, we conclude that they are essential for acute injury-induced muscle regeneration. It remains to be established whether there is any significant role for stem cells of other origins. The implications of our results for muscle stem cell-based therapy are discussed.
Natural history of cervical neoplasia: Overview and update

Current cervical cancer control strategies and specifically, the screening and treatment policies that have been used during the past 30 years, are based on an understanding of the natural history of cervical neoplasia that does not take into account the important role of human papillomavirus in cervical cancer pathogenesis. This survey presents a review of new data on the causes of cervical cancer and the role of human papillomavirus and recommends the integration of these data. Incorporation of new information on the role of human papillomavirus as the causative agent of most cervical cancers will allow the design of more efficient and more cost-effective strategies for cervical cancer control.
Robust relationship inference in genome-wide association studies

Motivation: Genome-wide association studies (GWASs) have been widely used to map loci contributing to variation in complex traits and risk of diseases in humans. Accurate specification of familial relationships is crucial for family-based GWAS, as well as in population-based GWAS with unknown (or unrecognized) family structure. The family structure in a GWAS should be routinely investigated using the SNP data prior to the analysis of population structure or phenotype. Existing algorithms for relationship inference have a major weakness of estimating allele frequencies at each SNP from the entire sample, under a strong assumption of homogeneous population structure. This assumption is often untenable. Results: Here, we present a rapid algorithm for relationship inference using high-throughput genotype data typical of GWAS that allows the presence of unknown population substructure. The relationship of any pair of individuals can be precisely inferred by robust estimation of their kinship coefficient, independent of sample composition or population structure (sample invariance). We present simulation experiments to demonstrate that the algorithm has sufficient power to provide reliable inference on millions of unrelated pairs and thousands of relative pairs (up to 3rd-degree relationships). Application of our robust algorithm to HapMap and GWAS datasets demonstrates that it performs properly even under extreme population stratification, while algorithms assuming a homogeneous population give systematically biased results. Our extremely efficient implementation performs relationship inference on millions of pairs of individuals in a matter of minutes, dozens of times faster than the most efficient existing algorithm known to us. Availability: Our robust relationship inference algorithm is implemented in a freely available software package, KING, available for download at http://people.virginia.edu/~wc9c/KING. Contact: wmchen@virginia.edu Supplementary information:Supplementary data are available at Bioinformatics online.
Pediatric liver transplantation for primary malignant liver tumors with a focus on hepatic epithelioid hemangioendothelioma: the UNOS experience

Treatment for HEH does not follow a standardized algorithm. From clinical experience, it is assumed that pediatric patients with HEH will fare as well as other common pediatric liver tumors post-OLT. The UNOS dataset was examined for patients with pediatric OLT between 1987 and 2007. Patients were grouped into non-tumors, HB, HCC, HEH, and rare liver tumors. COD analysis was calculated using Fisher's exact test. Patient, allograft, and recurrence-free survival were compared using Kaplan-Meier curves and log-rank tests. A total of 366 patients with pediatric OLT were identified with primary liver tumors (HB - 237, HCC - 58, HEH - 35, other - 36). HEH patient survival (five yr: 60.6%) was poorer than non-tumor OLTpatient survival (five yr: 84.4%). Survival was worse when compared to HB (five yr: 72%) and rare liver tumors (five yr: 78.9%), but better than HCC (five yr: 53.5%). Allograft survival in HEH (five yr: 50.1%) lies between HB (five yr: 63.6%) and HCC (five yr: 42.8%). COD analysis demonstrates recurrence as a major cause in HB and HCC, but not for HEH or other liver tumors. The data suggest that patient survival may not be as high as previously believed and further investigation is warranted.
Rituximab in the Treatment of Acquired Hemophilia

Objective:To review published literature evaluating the use of rituximab for treatment of acquired hemophilia.Data Sources:An English-language literature search was conducted using MEDLINE (1966–January 2006). References of identified articles were subsequently reviewed for additional data. Search terms included rituximab, acquired hemophilia, and inhibitors.Data Synthesis:Available data suggest that B-cell depletion by rituximab in patients with acquired hemophilia may contribute to the eradication of inhibitors to coagulation factors. B-cells have been shown to be essential in the development of autoimmunity or an acquired immune response. Beneficial effects of rituximab, after failure of established therapies, have been reported in case reports and one small, open-label trial.Conclusions:Although data are limited, administration of rituximab appears to be an effective option for treatment of patients with acquired hemophilia after established therapies have failed. Patients given rituximab experienced ...
Continuous Rearing of the Carrot Rust Fly, Psila rosae (Fab.)

A method for continuous rearing of the carrot rust fly, Psila rosae (Fabricius), has been developed for the first time. All stages of the rearing were conducted in a temperature cabinet maintained at 64 ± 2°F. Adults in a screen cage were fed water, honey, soybean flour and yeast. The females oviposited in the soil of potted carrots. Eggs were periodically removed with the top layer of soil to gallon jars containing several carrots layered in muck soil. Field collected puparia emerged satisfactorily at 70°F., but not at higher temperatures. In the laboratory population there was a preponderance of males. A generation of carrot rust flies was completed in approximately 80 days.
AUTOFLUORESCENCE SPECTROSCOPY OF OPTICALLY TRAPPED CELLS

Cellular autofluorescence spectra were monitored in a single-beam gradient force optical trap ("optical tweezers") in order to probe the physiological effects of near infrared and UVA (320-400 nm) microirradiation. Prior to trapping, Chinese hamster ovary cells exhibited weak UVA-excited autofluorescence with maxima at 455 nm characteristic of beta-nicotinamide adenine dinucleotide (phosphate) emission. No strong effect of a 1064 nm NIR microbeam on fluorescence intensity and spectral characteristics was found during trapping, even for power densities up to 70 MW/cm2 and radiant exposures of 100 GJ/cm2. In contrast to the 1064 nm trap, a 760 nm trapping beam caused a two-fold autofluorescence increase within 5 min (about 20 GJ/cm2). Exposure to 365 nm UVA (1 W/cm2) during 1064 nm trapping significantly altered cellular autofluorescence, causing, within 10 min, a five-fold increase and a 6 nm red shift versus initial levels. We conclude that 1064 nm microbeams can be applied for an extended period without producing autofluorescence changes characteristic of alterations in the cellular redox state. However, 760 nm effects may occur via a two-photon absorption mechanism, which, in a manner similar to UVA exposure, alters the redox balance and places the cell in a state of oxidative stress.
Improved Y factor noise measurement using the second stage contribution to advantage

The ultimate limitation to characterizing noise in microwave amplifiers derives from the noise inserted by the front-end of the measurement set. Typically a high-gain low noise preamplifier is used in the measurement set to improve accuracy. Even then there is a limit to the minimum noise factor that can be measured. In this paper an extended Y-factor noise measurement technique is presented that utilizes an amplifier stage identical and in addition to the amplifier under test to enhance measurement accuracy. Utilizing a calibrated noise source, the output noise power of first a forward cascade of the two amplifiers is measured and then that when the amplifiers are arranged in reverse cascade. The use of a spectrum analyzer or power meter with a readily measured change in noise power reading is required as well as a calibrated noise source.
Time resolution of rapid processes using numerical calculation and inversion of Laplace transforms

A method for the interpretation of data which results from a signal altered by a process of known weighting function was developed. The method is based on the numerical evaluation and inversion of the Laplace transform. For two different weighting functions, it is shown how narrow a signal can be interpreted accurately. The method is then applied to coal volatilization data.
Water transport coefficient distribution through the membrane in a polymer electrolyte fuel cell

Abstract The net water transport coefficient through the membrane, defined as the ratio of the net water flux from the anode to cathode to the protonic flux, is used as a quantitative measure of water management in a polymer electrolyte fuel cell (PEFC). In this paper we report on experimental measurements of the net water transport coefficient distribution for the first time. This is accomplished by making simultaneous current and species distribution measurements along the flow channel of an instrumented PEFC via a multi-channel potentiostat and two micro gas chromatographs. The net water transport coefficient profile along the flow channels is then determined by a control-volume analysis under various anode and cathode inlet relative humidity (RH) at 80 °C and 2 atm. It is found that the local current density is dominated by the membrane hydration and that the gas RH has a large effect on water transport through the membrane. Very small or negative water transport coefficients are obtained, indicating strong water back diffusion through the 30 μm Gore-Select ® membrane used in this study.
Control of Multi-Dimensional Linear Systems over Noisy Forward and Reverse Channels

We consider the problem of stabilizability of remote continous-time multi-dimensional LTI systems where both the forward (from the sensor to the controller) and the reverse (from the controller to the plant) channels are noisy and memoryless. By adopting an information theoretic approach, and using the theory of Markov processes, we obtain necessary and sufficient conditions for stabilizability, with the conditions being on channels, coders, and controllers. We show that the entire state and control spaces have to be encoded to obtain an invariant probability distribution, which leads to the necessity of using variable length codes in the case of discrete memoryless channels. We introduce a stabilizing variable length coding scheme through variable rate sampling of the continuous-time system. Control over continuous memoryless channels is also considered.
The Composition of Turkeys of Different Varieties and Strains

Abstract IN A previous paper, Harshaw and Rector (1940) reported the results of physical and chemical analyses of turkeys of different ages. Subsequent to this work, similar analyses have been made of turkeys of four varieties and strains reared in two different years. Maw (1933) found differences in physical composition between several breeds and crosses of chickens. Richter (1939) compared the physical and chemical composition of White Leghorns with that of crossbred chickens from several matings. Lehman (1939) made physical and chemical analyses of Bronze turkeys and several breeds of chickens. Apparently, however, there has been no systematic study reported that compares the composition of different varieties and strains of turkeys. EXPERIMENTAL METHODS In the investigation reported here, representative male and female turkeys of four varieties and strains were selected each year in 1940 and 1941 for analysis. They were produced on the same diets and under the same conditions, slaughtered, . . .
Entanglement friction and dynamics in blends of starlike and linear polymer molecules

We investigate relaxation dynamics in a series of six-arm star/linear 1,4-polybutadiene blends with mechanical rheometry measurements. Blend systems are formulated to systematically probe constraint release and arm relaxation dynamics. Zero shear viscosity and terminal relaxation times of star/linear polymer blends with fixed star arm molecular weights (M a ) and compositions (o S ) are found to follow nonmonotonic dependencies on the linear polymer molecular weight (M L ). At low values of o S , at least two scaling regimes are apparent from the data (ξ 0 ∼ M 2 L and ξ 0 ∼ M 3 L ), where ξ 0 refers to the zero shear viscosity or terminal relaxation time of the blend. The two regimes are separated by a critical linear polymer molecular weight M ** C that is more than 20 times larger than the critical molecular weight for entanglements. When the linear polymer contribution to blend properties is removed, a clear transition from dilution dynamics, ξ 0 ∼ M 0 L , to Rouse-like constraint-release dynamics, ξ 0 ∼ M 2,4+ L 0,4 , is apparent at low values of o S , At higher o S values, a new activated constraint-release dynamic regime is evident in which ξ 0 ∼ M α L and ξ 0 ∼ o β S , where α changes continuously from approximately 2 to 0.5 as o S increases and β varies from 2.0 to 1.0 as M L increases. The experimental results are compared with theoretical predictions based on a drag coupling model for entangled polymer liquids. All features observed experimentally are captured by this model, including the value of M ** C for the transition from dilution to Rouse constraint-release dynamics. Predictions of the drag coupling model are also compared with published data for the zero shear viscosity and terminal relaxation time in bidisperse linear polymer blends and pure entangled starlike molecules.
Microstructure, Flaw Tolerance, and Reliability of Ce‐TZP and Y‐TZP Ceramics

Ce-TZP and Y-TZP ceramics were heat-treated for various times and temperatures in order to vary the microstructure. Flaw tolerance was investigated using the indentation-strength test. Reliability was quantified using conventional two-parameter Weibull statistics. Some Ce-TZP specimens were indented at slightly elevated temperatures where no transformation was observed. Results indicated that the Ce-TZP specimens were extremely flaw tolerant, and showed a relatively high Weibull modulus that scaled with both R-curve behavior and flaw tolerance. Y-TZP, on the other hand, with very little if any R-curve behavior or flaw tolerance, had a low Weibull modulus. The results also show that flaw history, i.e., whether or not a transformation zone exists along the wake of the crack, has a significant influence on strength. Strength was much less dependent on initial crack size when the crack had an associated transformation zone, whereas strength was highly dependent on cracks typical of natural processing defects. It is argued that the improvement in reliability, flaw tolerance, and dependence on flaw history are all ramifications of pronounced R-curve behavior.