cssi/SciSciGPT-SciSciNet huggingface dataset:
Research Challenges and Bioethics Responsibilities in the Aftermath of the Presidential Apology to the Survivors of the U. S. Public Health Services Syphilis Study at Tuskegee

In 1997 President Clinton apologized to the survivors of the U.S. Public Health Service Syphilis Study. Since then, two of his recommendations have received little attention. First, he emphasized the need to remember the shameful past so we can build a better future for racial'ethnic minority populations. Second, he directed the creation in partnership with higher education to prepare training materials that would instruct biomedical researchers on the application of ethical principles to research with racial/ethnic minority populations. This article proposes the inclusion of these issues in the implementation of the Affordable Care Act. It asks, What is the right or good thing to do? What are our obligations to one another? Two challenges are examined: (a) Conducting research with African Americans without knowledge of bioethics specific to this population, and (b) the ethical dilemma of conducting research that does not adequately take into account the diversity within the Black population that is a con...
In Vitro Digestibility of Protein in Milled Sorghum and Other Processed Cereals With and Without Soy‐Fortification

In vitro pepsin protein digestibility (PD) of uncooked decorticated tow-tannin yellow sorghum was 75% and decreased to 59% after cooking. PD of 15% soy-sorghum blend was 84% before and 72% after cooking. Correlation of sorghum PD with analytical values showed that PD increased with decreasing fat, protein, fiber, Hunter “a”, and ash content and with increasing Hunter “L” and “b” values. PD of wheat flour, degermed corn meal, rolled oats, and bulgur was 80–98% before and 80–94% after cooking; PD of 12–15% soy-cereal blends was 88–97% before and 82–94% after cooking.
Uniform analogue to digital conversion of a normal random process

A method which minimises the noncompanded quantisation error, associated with the uniform analogue to digital conversion of a normally distributed random variable, is presented. The theoretical derivations are verified experimentally.
Evolution of selected volatiles in chitosan-coated strawberries ( Fragaria x ananassa ) during refrigerated storage.

The effect of chitosan coating on the evolution of several volatile compounds relevant to the strawberry (Fragaria × ananassa cv. Camarosa) aroma profile has been investigated. Strawberries dipped in chitosan acetate solution at 1 or 1.5% (w/w) and uncoated controls were stored at 10 °C for 1 week. Significant differences in aroma profile between coated and uncoated samples were observed. Most importantly, the buildup of the off-flavors acetaldehyde and ethanol was largely delayed in coated berries. With regard to the effect of chitosan on ester evolution, the levels of ethyl butanoate and ethyl hexanoate, important contributors to strawberry aroma related to fruity and sweet notes, were found to be enhanced in coated fruit. Acetate esters also increased during storage but more markedly in uncoated strawberries. These results show the potential of chitosan coatings in maintaining strawberry flavor during storage, something difficult to achieve with current conservation technologies. Moreover, differences ...
An automated method to analyze language use in patients with schizophrenia and their first-degree relatives

Communication disturbances are prevalent in schizophrenia, and since it is a heritable illness these are likely present - albeit in a muted form - in the relatives of patients. Given the time-consuming, and often subjective nature of discourse analysis, these deviances are frequently not assayed in large scale studies. Recent work in computational linguistics and statistical-based semantic analysis has shown the potential and power of automated analysis of communication. We present an automated and objective approach to modeling discourse that detects very subtle deviations between probands, their first-degree relatives and unrelated healthy controls. Although these findings should be regarded as preliminary due to the limitations of the data at our disposal, we present a brief analysis of the models that best differentiate these groups in order to illustrate the utility of the method for future explorations of how language components are differentially affected by familial and illness related issues.
CYTOPLASMIC DIMORPHISM WITHIN POLLEN GRAINS.

MATURE pollen grains contain a vegetative nucleus and either a generative nucleus or two sperm nuclei (derived by mitotic division of the generative nucleus). It has been generally accepted that the generative nucleus has an associated cytoplasm containing basic cell organelles1,2 and is separated from the vegetative cell cytoplasm by plasma membranes. While Venema and Koopmans3 have recently reported that a phase-contrast study of germinating pollen yielded no evidence for the ‘bicellular’4 nature of pollen grains, confirmation has been achieved by Safijovska2 utilizing light microscopy, and in a definitive manner in the electron microscopic examination reported by Bopp-Hassenkamp5. In addition to demonstrating the presence of a generative cell, the investigation by Bopp-Hassenkamp indicated that vegetative and generative cell cytoplasms differ in relative organelle numbers, and to a degree in organelle morphologies as seen in profile. Safijovska has observed that generative cell cytoplasm is longer-lived than vegetative cell cytoplasm in both aged pollen tubes and following pollen tube rupture. A comparative investigation of the fine structure of pollen cytoplasm now being conducted by me has made possible the observation of generative cells within pollen grains of a number of plant species.
Learning correlations in categorization tasks using large, ill-defined categories

The experiments revealed whether individual participants are sensitive to exemplar information in the form of within-category correlations between stimulus dimensions after training on large overlapping categories. Participants were trained in 1 of 2 categorization conditions. The sign of the correlation between dimensions differed across conditions, but the categorization rules that best separated the categories were identical. An unannounced attribute-prediction task followed categorization training. Several participants produced predictions consistent with the correct correlation between the dimensions. For other participants, the predictions reflected the correlation only within the region they had associated with the given category, even though the categories overlapped, suggesting that the decision boundary was explicitly represented in memory. Finally, for other participants, no correlational information appeared to be accessible for the prediction task.
The preparation and identification of various adducts of oxidized homogentisic acid and the development of a new sensitive colorimetric assay for homogentisic acid.

Abstract Homogentisic acid was converted to 1,4-benzoquinone-2-acetic acid (BQA). BQA was shown to undergo adduct formation with a number of different compounds containing free amino or sulfhydryl groups, including diethylenetriamine (DET) and D-penicillamine. The formation of a BQA adduct with DET was examined quantitatively and used as the basis for a simple, sensitive assay of homogentisic acid and BQA in serum and urine specimens.
A “middle road” approach to bridging the basic-applied divide in eyewitness identification research

Over a century of laboratory research has explored the mechanisms of memory using a variety of paradigms and stimuli. In addition, many researchers have taken up Neisser's challenge to examine memory under real-world conditions, most prominently including the eyewitness identification problem. Unfortunately, these 'high road' and 'low road' perspectives rarely communicate with one another, with the eyewitness field largely adopting an approach that focusses on methodological adherence to conditions that mimic real-world situations. In the current paper we advocate for a 'middle road' approach that includes a focus on theory development, an emphasis on the interaction between field and laboratory research and the implementation of convergent approaches to investigating eyewitness identification. We argue that the field would be invigorated by such an approach, with benefits accruing to our understanding of eyewitness identification and to the development of procedures that will ultimately improve eyewitness accuracy. Copyright © 2008 John Wiley & Sons, Ltd. Language: en
Where Commons Meet Commerce: Circulation and Sequestration Strategies in Indonesian Arts Economies

Production commons require social maintenance or stewardship. Stewardship practices, meaning patterns of valuing and caring for cultural resources, often restrict or foster access to knowledge within or beyond a self-defined group. I term these two protective but seemingly oppositional strategies as “sequestration” and “circulation,” respectively. How can we account for individual and group differences in the willingness to share knowledge and techniques for producing cultural expressions? To answer this question, I employ ethnographic narratives, mainly drawn from producers of Indonesian textiles (with comparisons to carvers, musicians, dramatists, and dancers), to construct typologies of informal stewardship rationales and techniques. Examples of circulation and sequestration strategies provide contextual data about what sways artisans' cooperative or competitive behaviors in “split economies.” This term refers to industries where expressive cultural productions serve both internal, embedded social purposes, contributing local cultural value mainly through delayed economic reciprocity, and external commodity markets. Untangling the economic, sociological, and identity boundary aspects of “value” helps clarify conundrums about when producers want to circulate versus sequester information. Sequestration strategies often protect inherited privileges or commercial market share of technically vulnerable industries. Yet, the classificatory divide between community and market economy realms is shown to be subject to considerable slippage.
The strategic evolution of large US law firms

Abstract In recent years, large US law firms have been undergoing significant changes. Most have switched from a professional model (P2 form) to a corporate business model, employing competitive strategies and a profit orientation. As the market for corporate legal services became more competitive, many large US law firms began to diversify the services they offer and expand their operations into new geographic regions of the country and into international markets. They even engaged in acquisitions and learned to manage and leverage their critical resources, human capital and relational capital. As a result, most of these law firms have added more professional management. All in all, the services law firms offer and the rivals with which they must contend have changed substantially over the last 15 years.
AFDC and births to unwed women

Abstract Most studies by economists have been inconclusive when seeking a consistent relationship between income-support programs [like aid to families with dependent children (AFDC)] and births to unwed women (or, as the literature traditionally terms it, illegitimacy). But a recent study [Southern Econ. J. 62 (1995) 44] reports a large, positive and statistically significant relationship when data are weighted to reflect differences in propensities toward illegitimacy. We find that the 1995 study appears to rely upon erroneous data and irregular econometric technique. When these are remedied, the major results are reversed. We then suggest that a switching regimes methodology, with parameters influenced by other variables, is more appropriate to the issue. Our empirical results confirm the literature's consensus that AFDC and illegitimacy do not appear to be strongly related.
Using the DNA alkaline unwinding assay to detect DNA damage in laboratory and environmentally exposed cells and tissues

Abstract The DNA alkaline unwinding assay is being evaluated for use in the detection of DNA damage in marine animals exposed to environmental pollutants. In preliminary work, DNA unwinding methods were used with in vitro cell systems to demonstrate DNA strand breaks. Cultured mammalian fibroblasts and sperm from marine fish and invertebrates (Pseudopleuronectes, Arbacia and Mytilus) showed concentration-dependent increases in DNA strand breaks after brief exposures to alkylating agents. DNA unwinding methods were also used on DNA extracted from marine animals injected with genotoxicants and from animals exposed in situ at an estuarine site. Gills from blue mussels caged at the New Bedford Harbor Superfund Site (MA, USA) highly contaminated with many organic (e.g. PCBs) and inorganic contaminants, were also examined. A significant increase in DNA strand breaks was seen in gill tissues of animals held in the contaminated site for as little as 3 days. Although not as severe, an increase in strand breaks was also seen in animals held at the control site for 28 days. This apparent damage may have resulted from low-level contamination and/or from generally poor tissue condition. These results suggest that DNA alkaline unwinding results from controlled experiments using cells briefly exposed to toxicants can be used to identify DNA strand breaking agents. While whole-animal exposures to toxicants may affect DNA integrity, unwinding results may not specifically reflect genotoxicity.
Wanting, Having, and Getting: A Note on Fodor and Lepore 1998

This article takes up Fodor and Lepore's (1998) account of the meaning of [want DP]structures, according to which the verb to have is introduced at interpretation. With certain DP complements a wan...
Factors controlling the marine geochemistry of fluorine

Abstract The factors controlling the marine geochemistry of fluorine and the behavior of fluorine in the major sedimentary cycle today have been investigated with analyses of minerals from marine and terrestrial sediments. Calcium carbonate precipitation dominates the removal of dissolved fluoride from sea water, with incorporation into calcium phosphates apparently the next most important removal mechanism. An enrichment of fluorine over chlorine by a factor of about 105 occurs during CaCO3, precipitation. The residence time of the fluoride ion in sea water is calculated from its sedimentation rate to be a few million years, similar to that of calcium. Fluorine is being removed from sea water about 100 times faster than chlorine, but not nearly as fast as elements such as Fe or Al. Calcium carbonate and phosphate precipitation together can account for at most 10–20 % of the dissolved fluoride brought annually by rivers to the oceans. Atmospheric precipitations contain enough fluorine, the major part of which has apparently come from the sea, to provide most of the fluorine in the river waters. Only a small fraction of the fluorine found in atmospheric precipitations can be explained by volcanic and industrial inputs, or by soil dust. Since most of the fluoride in river waters is therefore cyclic, the oceans can closely approach a steady state for fluorine, despite the apparent discrepancy in injection and removal rates. The F Cl ratio in rain and snow is 10–1000 times that in sea water, so fluorine is apparently being preferentially injected into the atmosphere at the sea surface. As atmospheric precipitation weathers crustal rocks and soils it dissolves out relatively little fluorine. Most of the fluorine mobilized during weathering remains bound in the solid phases such as the clays. Upon reaching the sea, the clays remove very little, if any, fluoride from solution as they pass to the sediments. Their relatively large fluorine contents are thus unreactive in the major sedimentary cycle.
Effectiveness of cognitive apprenticeship learning (CAL) and cognitive tutors (CT) for problem solving using fundamental programming concepts

In this paper, we describe our approach in addressing learning challenges students experience in introductory programming courses. We combine two effective instructional methodologies to help students learn to plan programs prior to writing code: Cognitive Apprenticeship Learning (CAL) and Cognitive Tutors (CT). In the CAL component, the instructor models program planning in class and paper handouts are used to scaffold program planning in homework assignments. In CAL-CT, the program-planning process is also supported by a computer tutor which provides step-by-step feedback and advice. The results show that the combined CAL-CT approach yielded substantial gains over traditional instruction. Its advantage over the CAL-Only approach is also significant.
Leishmania major:Differential Resistance to Infection in C57BL/6 (High Interferon-α/β) and Congenic B6.C-H-28c(Low Interferon-α/β) Mice

In murine cutaneous leishmaniasis caused by Leishmania major (Lm), resistance often associates with the outgrowth of Lm-specific Th1 cells. Parasites are eliminated by Th1-mediated activation of infected macrophages (M phi) which destroy Lm by producing toxic nitrogen and oxygen radicals. The cytokine IFN-alpha activates microbicidal functions of M phis and facilitates outgrowth of Th1 cells. Therefore, we compared the course of infection with Lm in resistant C57BL/6 mice, bearing the If-1h high expression allele for IFN-alpha/beta, with the congenic B6.C-H-28c mouse, bearing the If-1I low expression allele from the Lm-susceptible BALB/c strain. We observed that B6.C-H-28c animals developed up to 70% larger footpad lesions and harbored up to 1000-fold more parasites than C57BL/6 mice. Furthermore, peak Lm-specific IFN-gamma production in the B6.C-H-28c animals was lower and delayed by approximately 2 weeks, whereas IL-4 production was higher and persisted approximately 2 weeks longer. Since these results suggested that IFN-alpha/beta plays a protective role in mice infected with Lm, we determined whether infusing B6.C-H-28c mice with IFN-alpha would influence the course of infection with Lm. Unfortunately, the mice developed severe peritoneal hemorrhaging in response to injection with IFN-alpha. Therefore, we examined the ability of IFN-alpha to activate M phis to destroy Lm in vitro. We observed that rIFN-alpha could synergize with subactivating doses of LPS to activate both C57BL/6 and BALB/c peritoneal M phis to produce NO and to kill intracellular Lm. Taken as a whole, these results suggest that type I interferons may play a protective role in cutaneous leishmaniasis.
Symposium on peace and security in India: An introduction

The World Health Organization categorizes violence as including self-harm such as suicide, interpersonal violence such as domestic violence and violent crime, and collective violence such as inter-communal violence and international war. Peace and security issues in India abound in all of these categories. To name a few, they range from cases of farmer suicides, violence against women and female infanticide, religious, communal, and political violence, land-acquisition disputes, crime, policing, regional disputes between Indian states and other groups over scarce natural resources, separatist movements, military expenditure and policy, and territorial disputes and arms races with neighboring countries. This symposium focuses on points of interpersonal and inter-communal violence, largely restricting its attention to India’s internal rather than external concerns.
Carbohydrate histochemistry of rat respiratory glands.

Cytochemical methods applied to examination of rat respiratory tract glands have revealed diversity of secretory complex carbohydrates. With the Alcian blue-periodic acid Schiff (AB-PAS) and the high iron diamine (HID) techniques at the light microscopic level, certain patterns of glycoprotein content were noted at various levels of the respiratory tract. Serous tubules and demilunes found in abundance in laryngeal and tracheal glands contained neutral glycoprotein. Mucous tubules found in abundance in epiglottal and laryngeal glands and in lesser number in tracheal glands most often produced sulfated glycoprotein. However, mucous tubules in epiglottal and tracheal glands contained a few cells with sialylated glycoprotein, and mucous tubules in some areas in laryngeal glands contained mainly cells producing sialylated glycoprotein. Mucous ducts found in abundance in lower laryngeal and tracheal glands formed mainly sialylated glycoprotein and contained infrequent cells with sulfated glycoprotein. The type of glycoprotein found in each cell type by light microscopy was confirmed at the ultrastructural level by the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP), dialyzed iron (DI) and high iron diamine (HID) methods. Serous cell granules displayed light reactivity with the PA-TCH-SP method and no DI or HID affinity and were judged to contain sparse neutral glycoprotein. Serous granules disclosed negative central foci with the PA-TCH-SP method. Granules of most mucous tubule cells stained strongly with the PA-TCH-SP and HID procedures and contained abundant sulfated glycoprotein. Occasional mucous tubules stained with the PA-TCH-SP but not with the HID method and apparently corresponded with cells judged to form sialylated glycoprotein from their blue staining with the HID-AB sequence. Two zones within individual granules in some cells revealed different HID staining intensity and appeared to differ in the amount or kind of sulfated glycoprotein they contained. Some cells exhibited granule heterogeneity containing both HID-positive and unstained granules. Spherical cores present in granules of mucous tubules below the upper laryngeal level occasionally appeared bizonal and invariably lacked reactivity demonstrative of complex carbohydrate. Mucous duct cell granules stained heavily with the PA-TCH-SP and DI methods and reacted infrequently with the HID procedure and were considered generally to contain sialylated glycoprotein, and occasionally to form sulfated glycoprotein. The three carbohydrate stains distinguished a heavily and a moderately reactive zone in the cortex outside the monophasic or biphasic, carbohydrate-free cores in granules of some mucous duct cells.
Clinical review 12: The use and misuse of the sensitive thyrotropin assays.

Since its introduction five years ago, the sensitive TSH (S-TSH) immunometric assay (IMA) has established itself as an important new thyroid test. In fact, TSH IMAs have now replaced the less sensitive first generation TSH radioimmunoassay (RIA) methods. As implied by the term sensitive, these TSH IMAs provide both improved analytic assay precision as well as clinical sensitivity for routinely distinguishing the suppressed serum TSH values characteristic of hyperthyroidism from euthyroidism (1). This improved sensitivity largely results from the IMA sandwich assay configuration in which two anti-TSH antibodies are employed, rather than the single antibody RIA methods (competitive ligand binding assays). Usually one or both of these antibodies are monoclonal and, therefore, possess a high degree of specificity for the TSH epitopes. The first antibody, which is present in excess and bound to a solid support such as a tube wall or bead, is directed at the specific β-subunit of TSH.
The Value of Certain Factors for Direct and Differential Prediction of Academic Success

Intelligence tests are being used extensively for purposes of prediction; however, studies carried on by numerous investigators under a wide variety of conditions have adequately demonstrated that the functions measured by the types of intelligence tests now available show only a moderate degree of relationship to academic achievement. Reviews of these studies indicate that, among typical groups of high school students, the Pearson product moment coefficient of correlation between in telligence test results and academic achieve ment is approximately .50 (Eurich and Car roll,1 Lee,2 Pintner,3 Segel,4 Turney5). This degree of relationship suggests that non intellectual factors play a large part in con ditioning scholastic success. In order to be able to predict academic success more ade quately than is possible by using intelligence tests alone, one must segregate those non intellectual factors which, independent of the functions measured by our available intelli gence tests, bear a significant relationship to measures of academic performance. The present study represents an attempt to determine the value of a number of non intellectual factors for predicting school suc cess as measured by teachers7 marks. The purpose of this study is to present an analysis of data in order to reveal any pos sible values that chronological age at entrance to elementary school, amount of education of father, amount of education of mother, and occupational status of father may have for direct and differential prediction of academic success as measured by teachers' marks. Data were available in the records at Uni versity High School, University of Minne sota, for 196 boys and 156 girls. All of these cases had been graduated from University High School. The following ten variables were tabulated for each of the 352 cases:
Child Development Accounts and saving for children's future: Do financial incentives matter?

Abstract This study examines savings outcomes and the role of financial incentives in a community-based, asset-building program for low- and moderate-income children. Data are from the first large-scale demonstration of Child Development Accounts (CDAs) in the United States. Two savings outcomes are studied: (1) average quarterly net savings (mean $29.58), and (2) average total accumulation (mean $1518.24, including incentives). Multivariate analysis finds that different incentives have different associations with the two savings outcomes. This study informs public policy in general and savings policy in particular, by expanding knowledge of the role of incentives in saving and building assets for children.
Aneurysm of an aberrant right subclavian artery—Computed tomography

An aneurysm of an aberrant right subclavian artery was diagnosed with computed tomography (CT) in a 77-year-old man with an asymptomatic mediastinal mass at admission. Although CT clearly demonstrated this rare congenital anomaly, further radiologic study or surgery was not attempted because of the patient's advanced age and lack of symptoms.
Electrical Surface Breakdown of Thin-Film ZNO Varistors

Samples of zinc oxide varistor material representing a thin film are studied. An electrical discharge is consistently produced at electric field strengths and energy levels both well below those required to cause bulk material with the same composition to fail. The investigation examines each of the major issues which could be responsible for this anomalous behavior. Electrode/sample contact integrity, electrode shape, and surface considerations are studied. It is concluded that the discharge is directly related to the surface preparation. Study of the sample surface under different preparation conditions indicates that macroscopic as well as microscopic surface properties influence the behavior of the discharge.
On the mechanism of morphological differentiation in the nervous system. I. The transformation of a neural plate into a neural tube

The early development of the vertebrate nervous system is among the commonplaces of descriptive embryology. Every elementary text-book tells us that the first clearly recognizable rudiment is a flat patch of cells ectodermal in nature; how in due course of time after the appearance of a longitudinal furrow, the edges of this plate rise, meet in the mid-dorsal line, and fuse to form a tube, enclosing the neurocoel. What however are the forces at work when the primitive plate changes into a tube? This question was in the mind of His1 when he wrote his classic letters, ‘‘Unsere Korperform.” I n the fourth of these lucid epistles, His shows that the nervous system, during the period of folding, grows faster than the surrounding tissues with which it is continuous. On the assumption that these resist any increase in the width of the neural plate, he shows that the latter, must fold under the mechanical necessities of the case. Models, in which the entire process could be simulated at will, helped to emphasize the argument. The well-known experiments of ROUX,~ however, proved that this view of the origin of the neural groove is mechanically impossible, despite the inequalities of growth emphasized by His.
The neuro-ophthalmology of systemic lupus erythematosus

Experience with many patients with SLE and a review of the literature indicate that neuro-ophthalmic abnormalities are frequently found in patients with SLE. The optic disc may become swollen in patients with SLE either as a result of local retinal lesions or secondary to increased intracranial pressure. Some of the cases with increased intracranial pressure resemble the entity of pseudotumor cerebri. Patients with SLE may develop an optic neuropathy. The pathogenesis appears either to be demyelinative or secondary to parenchymal microinfarcts. Some of the patients develop a clinical syndrome identical to Devic's desease. The response to corticosteroids is unpredictable. Acute anterior ischemic optic neuropathy is rare in patients with SLE. Homonymous hemianopias may occur in isolation or in association with hemiplegia, aphasia or hemisensory defects. Both formed and unformed visual hallucinations are commonly encountered, and patients may have transient amaurosis or geniculocalcarine (“cortical”) blindness. Visual hallucinations identical to those seen in migraine, and vascular headaches appear to be more common in patients with SLE than among controls. Diplopia occurs in patients with SLE most often as a transient phenomenon associated with vertigo. Transient ptosis may also occur. These findings, like the transient bilateral amaurosis, suggest the picture of insufficiency in the vertebrobasilar system. Diplopia may also occur from fixed lesions in the brain stem and several instances of internuclear ophthalmoplegia have been recognized. If ophthalmoplegia or ptosis develop in a patient with SLE it should suggest the possibility that the patient has myasthenia gravis which occurs with unusually high frequency among patients with SLE.
Frequency Response Model for Branched Pneumatic Sensing Systems

A frequency response model for branched pneumatic sensors is developed. A typical application is prediction of pneumatic latency and attenuation in aircraft airdata systems, where pneumatic lines are branched to feed a variety of instruments, navigation systems, and pilot displays. The model is developed using small perturbations of the unsteady Navier-Stokes equations. The linearized equations are radially averaged and expressed in the frequency domain. The result is one-dimensional boundary value problem where the pressure oscillation for a given frequency is expressed as a function of position within the sensor. Assuming constant tube geometry and gas properties along an arbitrarily small tubing element allows a closed-form solution of the boundary value equations. This solution becomes a fundamental building block for solving the frequency response of more complex pneumatic geometries. The analysis process employed is similar to applying Kirchhoff's laws to analyze complex electrical circuits. The model predictions are compared against experimental data generated for a simple two-branch configuration. Comparisons for both symmetrical and unbalanced branches are presented. Experiment setup and procedures are described. The comparisons show that the model accurately predicts both the magnitude and phase frequency response of dominant and reflected wave harmonics within each branch of the system.
Realistic plant species losses reduce invasion resistance in a California serpentine grassland

Summary 1. The majority of experiments examining effects of species diversity on ecosystem functioning have randomly manipulated species richness. More recent studies demonstrate that realistic species losses have dramatically different effects on ecosystem functioning than those of randomized losses, but these results are based primarily on microcosm experiments or modelling efforts. 2. We conducted a field-based experiment directly comparing the consequences of realistic and randomized plant species losses on invasion resistance and productivity in a native-dominated serpentine grassland in California, USA. The realistic species loss order was based on nested subset analysis of long-term presence ⁄ absence data from our research site and reflects differing species sensitivities to prolonged drought. 3. Biomass of exotic invasive plant species was inversely related to native species richness in the realistic loss order. In contrast, invader biomass was consistently low across species richness levels in the randomized species loss order, with no effect of native species richness on invader biomass among randomized assemblages. Although total above-ground plant biomass increased with soil depth (a proxy for resource availability) in both realistic and randomized assemblages, soil depth influenced invader biomass only in the randomized assemblages. 4. Synthesis. Our results illustrate that the functional consequences of realistic species losses can differ distinctly from those of randomized species losses and that incorporation of realistic species loss scenarios can increase the relevance of experiments linking biodiversity and ecosystem functioning to conservation in the face of anthropogenic global change.
The Signal Processing Information Base: a road to electronic information exchange

The Signal Processing Information Base (SPIB) project, funded by the NSF and supported by the Signal Processing Society, represents a first attempt to make widely available data, papers, software, and paper in a timely, effective fashion. Information dissemination via computer networks and sifting through information with search software would seem straightforward. However, modern publication involves not only prose, but also tables, graphics, plots, and many kinds of data displays-images, which makes the representation problem more severe. Policy oriented issues such as peer review and copyright have also emerged to complicate the desire to publish information quickly and widely. As the SPIB evolves, in concert with similar projects in a wide variety of disciplines, into a seamless, cross-linked, indexed, computer network that makes information available rapidly, these difficulties will intensify unless software environments are created that can support high-speed networks and platforms, and publication policies change to facilitate rapid dissemination. >
Free electron motion in an electromagnetic field at zero temperature and the dependence on its rest mass

Efforts to achieve quantum computation, teleportation, and communication depend on minimizing decoherence, which is the destruction of a quantum interference pattern. Here, we examine effects arising from the universal zero-point (temperature T = 0) oscillations of the electromagnetic field on a free electron in a Schrodinger cat superposition state. A unique conclusion is that the spreading of an electron wavepacket and the rate of decay of decoherence depend on the bare mass m of the electron. However, only for m = 0 does decoherence occur and the fact that it occurs almost instantly is ruled out by electron interference experiments. For m ≠ 0, the electron essentially behaves as a free particle.
Feedforward control laws for the buck converter

Two types of PWM are reviewed which can be used to produce a unified implementation of the variety of feedforward schemes proposed for the buck converter over 15 years. Nonlinear input-voltage- and output-current-feedforward control are shown to unilateralize the buck converter, eliminating interaction of the input and output filters, and producing an ideal voltage source and current sink, respectively. A novel feedforward capable of transferring a programmed power is proposed. >
Racial and Ethnic Residential Segregation, the Neighborhood Socioeconomic Environment, and Obesity Among Blacks and Mexican Americans

We used cross-sectional data on 2,660 black and 2,611 Mexican-American adult participants in the National Health and Nutrition Examination Survey (1999–2006) to investigate the association between metropolitan-level racial/ethnic residential segregation and obesity and to determine whether it was mediated by the neighborhood socioeconomic environment. Residential segregation was measured using the black and Hispanic isolation indices. Neighborhood poverty and negative income incongruity were assessed as mediators. Multilevel Poisson regression with robust variance estimates was used to estimate prevalence ratios. There was no relationship between segregation and obesity among men. Among black women, in age-, nativity-, and metropolitan demographic-adjusted models, high segregation was associated with a 1.29 (95% confidence interval (CI): 1.00, 1.65) times higher obesity prevalence than was low segregation; medium segregation was associated with a 1.35 (95% CI: 1.07, 1.70) times higher obesity prevalence. Mexican-American women living in high versus low segregation areas had a significantly lower obesity prevalence (prevalence ratio, 0.54; 95% CI: 0.33, 0.90), but there was no difference between those living in medium versus low segregation areas. These associations were not mediated by neighborhood poverty or negative income incongruity. These findings suggest variability in the interrelationships between residential segregation and obesity for black and Mexican-American women.
Geometrical structure of monobridged disilyene Si(H)SiH

By means of Fourier transform microwave spectroscopy of a supersonic molecular beam, we have detected the more abundant rare isotopic species of monobridged Si(H)SiH, and determined of its geometrical structure by isotopic substitution. Unexpected abundance anomalies of the singly deuterated isotopic species with respect to normal and Si(D)SiD were observed with equal mixtures of SiH4 and SiD4. This nonstatistical distribution is consistent with Si(H)SiH formation which is dominated by the reaction of a bare Si atom or ion with either SiH2 or SiH4. Dedicated laboratory searches were also undertaken for the remaining singlet isomer, H2SiSi, so far without success. From the absence of lines at the expected frequencies we conclude that H2SiSi is at least 50 times less abundant than Si(H)SiH. Because it is only slightly less stable than Si(H)SiH and because the barrier to isomerization is calculated to be quite low, H2SiSi may rearrange on the timescale of the supersonic expansion to Si(H)SiH.
Apoptotic photoreceptor degeneration in experimental retinal detachment.

Purpose. To investigate the possibility that cell death in retinal detachment may occur by reactivation of apoptotic programmed cell death mechanisms. Methods. Unilateral retinal detachments were created in adult cats using 0.25% sodium hyaluronate; detached and control retinas were studied at different intervals. Internucleosomal DNA fragmentation (one of the landmarks of apoptosis) was investigated in tissue sections with the TUNEL technique, which uses terminal transferase to label with biotinylated nucleotides the 3' ends of DNA fragments. Sections also were labeled with propidium iodide, which intensely stains pyknotic nuclei. In addition, one time point was selected for analysis with electron microscopy. Results. TUNEL-positive (T+) and propidium iodide-positive (PI+) cells almost never were observed in retinas from control eyes, but they were abundant at defined time points after retinal detachment, appearing almost exclusively in the photoreceptor layer. Their frequency was particularly high 1 to 3 days after detachment but declined rapidly over the next several weeks. T+ cells were still present 28 days after retinal detachment. Electron microscopy also revealed evidence of apoptotic cells after retinal detachment. Conclusions. Results are consistent with the hypothesis that photoreceptor degeneration after retinal detachment occurs through apoptosis, usually associated with intrinsic, programmed cell death mechanisms. The detection of a rapid wave of photoreceptor degeneration seems to suggest that early therapeutic interventions might be recommended; agents capable of interfering with the apoptotic mechanism could have a role in the prevention of cell losses that represent a critical complication of retinal detachment. Invest Ophthalmol Vis Sci. 1995;36:990-996. JVetinal detachment (RD) is a serious clinical problem characterized by separation of the sensory retina from the RPE with fluid accumulation in the intervening space. The incidence of RD is approximately 5 to 12 persons per 100,000 per year for phakic, nontraumatic forms'; traumatic RD is seen most frequently among men. 2 Primary RD is usually preceded by poste
Update on deep brain stimulation in Parkinson's disease

Deep brain stimulation (DBS) is considered a safe and well tolerated surgical procedure to alleviate Parkinson’s disease (PD) and other movement disorders symptoms along with some psychiatric conditions. Over the last few decades DBS has been shown to provide remarkable therapeutic effect on carefully selected patients. Although its precise mechanism of action is still unknown, DBS improves motor functions and therefore quality of life. To date, two main targets have emerged in PD patients: the globus pallidus pars interna and the subthalamic nucleus. Two other targets, the ventralis intermedius and zona incerta have also been selectively used, especially in tremor-dominant PD patients. The main indications for PD DBS have traditionally been motor fluctuations, debilitating medication induced dyskinesias, unpredictable “off time” state, and medication refractory tremor. Medication refractory tremor and intolerable dyskinesia are potential palliative indications. Besides aforementioned targets, the brainstem pedunculopontine nucleus (PPN) is under investigation for the treatment of ON-state freezing of gait and postural instability. In this article, we will review the most recent literature on DBS therapy for PD, including cutting-edge advances and data supporting the role of DBS in advanced neural-network modulation.
Measurements and predictions of a highly turbulent flowfield in a turbine vane passage

As highly turbulent flow passes through downstream airfoil passages in a gas turbine engine, it is subjected to a complex geometry designed to accelerate and turn the flow. This acceleration and streamline curvature subject the turbulent flow to high mean flow strains. We present both experimental measurements and computational predictions for highly turbulent flow as it progresses through a passage of a gas turbine stator vane. Three-component velocity fields at the vane midspan were measured for inlet turbulence levels of 0.6%, 10%, and 19.5%, The turbulent kinetic energy increased through the passage by 130% for the 10% inlet turbulence and, because the dissipation rate was higher for the 19.5% inlet turbulence, the turbulent kinetic energy increased by only 31%. With a mean flow acceleration of five through the passage, the exiting local turbulence levels were 3% and 6% for the respective 10% and 19.5% inlet turbulence levels. Computational RANS predictions were compared with the measurements using four different turbulence models including the κ-e, Renormalization Group (RNG) κ-e, realizable κ-e, and Reynolds stress model
Moving Vortices on the Sphere: A Test Case for Horizontal Advection Problems

A new two-dimensional advection test on the surface of the sphere is proposed. The test combines a solid-body rotation and a deformational flow field to form moving vortices over the surface of the sphere. The resulting time-dependent deforming vortex centers are located on diametrically opposite sides of the sphere and move along a predetermined great circle trajectory. The horizontal wind field is deformational and nondivergent, and the analytic solution is known at any time. During one revolution around the sphere the initially smooth transported scalar develops strong gradients. Such an approach is therefore more challenging than existing advection test cases on the sphere. To demonstrate the effectiveness and versatility of the proposed test, three different advection schemes are employed, such as a discontinuous Galerkin method on a cubed-sphere mesh, a classical semi-Lagrangian method, and a finite-volume algorithm with adaptive mesh refinement (AMR) on a regular latitude–longitude grid. The numerical results are compared with the analytic solution for different flow orientation angles on the sphere.
Softer soju in South Korea

This paper explores the ascendancy of ‘softness’ in South Korea as it is experienced through the qualia of one of Korea’s most important social rituals: drinking soju. I combine an analysis of ethn...
Sex hormone replacement therapy and modulation of vascular function in cardiovascular disease

Epidemiological and experimental studies suggest vascular protective effects of estrogen. Cardiovascular disease (CVD) is less common in premenopausal women than in men and postmenopausal women. Cytosolic/nuclear estrogen receptors (ERs) have been shown to mediate genomic effects that stimulate endothelial cell growth but inhibit vascular smooth muscle proliferation. However, the Heart and Estrogen/Progestin Replacement Study (HERS), HERS-II and Women's Health Initiative clinical trials demonstrated that hormone replacement therapy (HRT) may not provide vascular benefits in postmenopausal women and may instead trigger adverse cardiovascular events. HRT may not provide vascular benefits because of the type of hormone used. Oral estrogens are biologically transformed by first-pass metabolism in the liver. By contrast, transdermal preparations avoid first pass metabolism. Also, natural estrogens and phytoestrogens may provide alternatives to synthetic estrogens. Furthermore, specific ER modulators could minimize the adverse effects of HRT, including breast cancer. HRT failure in CVD could also be related to changes in vascular ERs. Genetic polymorphism and postmenopausal decrease in vascular ERs or the downstream signaling mechanisms may reduce the effects of HRT. HRT in the late postmenopausal period may not be as effective as during menopausal transition. Additionally, while HRT may aggravate pre-existing CVD, it may thwart its development if used in a timely fashion. Lastly, the vascular effects of progesterone and testosterone, as well as modulators of their receptors, may modify the effects of estrogen and thereby provide alternative HRT strategies. Thus, the beneficial effects of HRT in postmenopausal CVD can be enhanced by customizing the HRT type, dose, route of administration and timing depending on the subject's age and cardiovascular condition.