cssi/SciSciGPT-SciSciNet huggingface dataset:
Coupling between horizontal cells in the carp retina revealed by diffusion of lucifer yellow

Electrical coupling among 4 different types of horizontal cells in Cyprinus carpio was examined from the diffusion of the intracellularly injected Lucifer yellow. The type of horizontal cells was indentified by a spectral response and by a distinct morphology when the retina was viewed in flat mounts under a fluorescence microscope. Lucifer yellow diffused from the injected cell into surrounding cells, and in all of these preparations, diffusion was limited to horizontal cells of the same morphological type. Axons of horizontal cells were found to be coupled, and also at axons the coupling is likely to be limited to the same cell type.
A randomized phase III comparative trial of immediate consolidation with high-dose chemotherapy and autologous peripheral blood progenitor cell support compared to observation with delayed consolidation in women with metastatic breast cancer and only bone metastases following intensive induction chemotherapy

The prognosis for patients with metastatic breast cancer remains poor. Metastatic breast cancer confined to the bones may have a better prognosis, especially hormone receptor-positive disease. We performed a prospective, randomized clinical trial to compare immediate consolidation with high-dose chemotherapy and hematopoietic support versus observation with high-dose consolidation at the time of disease progression in women with metastatic breast cancer and only bone metastases. The patients received chemotherapy with doxorubicin, 5-fluorouracil and methotrexate before randomization. In all, 85 patients were enrolled and 69 were randomized. The median follow-up is 8.1 years from randomization. The median event-free survival (EFS) for the immediate transplant arm is 12 months and for the observation arm is 4.3 months (P<0.0001). The median overall survival for the immediate transplant arm is 2.97 years and for the observation arm 1.81 years, a difference that is not statistically significant. Immediate high-dose chemotherapy and radiation therapy as consolidation offers a clinically and statistically significant improvement in EFS compared with radiation therapy alone following induction chemotherapy for women with metastatic breast cancer confined to the bones.
The diverse career orientations of MIS personnel

Past studies have found different dominant career anchors present among information system (IS) personnel. This study provides additional evidence that IS personnel have a diversity of career orientations and that the orientations can vary according to external conditions. A survey of IS personnel supports the premise that each professional situation and each individual is unique. Organizations are better off creating flexible career structures rather than rigid career paths and must be prepared to adjust to changes in the environment.
Resolution of multi-component exponential decay curves using Fourier transforms.

A frequently encountered problem in many branches of science involves the resolution of experimental data in a sum of exponentials of the form to estimate the physically significant parameters Ni° and λ i and to determine n, the number of components. The components may be separate and unrelated, or there may be decay chains where some components are produced as the result of the disappearance of other components. In the present approach the exponential series is represented by a Laplace integral equation . This equation is inverted by a method of Fourier transforms. The results of the analysis appear in the form of a frequency spectrum. Each true peak in the spectrum indicates a component, the abscissa value at the center of the peak is the decay constant λi while the height of the peak is directly proportional to Ni°/λi.
Annotating the semantic web using natural language

Because the ultimate purpose of the Semantic Web is to help users better locate, organize, and process content, we believe that it should be grounded in the information access method humans are most comfortable with---natural language. However, the Resource Description Framework (RDF), the foundation of the Semantic Web, was designed to be easily processed by computers, not humans. To render RDF more friendly to humans, we propose to augment it with natural language annotations, or metadata written in everyday language. We argue that natural language annotations, parsed into computer-readable representations, are not only intuitive and effective, but can also accelerate the pace with which the Semantic Web is being adopted. We believe that our technology can facilitate a happy marriage between natural language technology and the Semantic Web vision.
RNA-Catalyzed CoA, NAD, and FAD synthesis from phosphopantetheine, NMN, and FMN.

A novel in vitro selection method was developed to isolate RNA sequences with coenzyme-synthesizing activities. We used size-heterogeneous libraries containing randomized ribonucleotide sequences of four different lengths (30N, 60N, 100N, and 140N), all with 5‘-ATP initiation. Two RNAs, CoES7 (30N) and CoES21 (60N), are able to catalyze the synthesis of three common coenzymes, CoA, NAD, and FAD, from their precursors, 4‘-phosphopantetheine, NMN, and FMN, respectively. Both ribozymes require divalent manganese for activities. The results support the availability of these coenzymes in an RNA world, and point to a chemical explanation for the complex bipartite structures of many coenzymes.
Messenger ribonucleic acid for the gonadal luteinizing hormone/human chorionic gonadotropin receptor is not present in human endometrium

Abstract Objective: To determine whether messenger RNA for the gonadal LH/hCG receptor is present in human endometrium with the use of reverse-transcriptase polymerase chain reaction. Design: In vitro experiment. Setting: Academic medical center. Patient(s): Premenopausal women who were not receiving hormonally active medications and who were undergoing hysterectomy for uterine leiomyomas, menorrhagia, pelvic pain, or uterine prolapse. Intervention(s): Tissue from hysterectomy specimens was processed for RNA and treated with deoxyribonuclease where appropriate, and RNA was reverse-transcribed to complementary DNA. Main Outcome Measure(s): An appropriately sized band after reverse-transcriptase polymerase chain reaction, followed by sequencing to confirm the results. Result(s): A primer pair that spanned the extracellular domain was unable to amplify receptor complementary DNA from human endometrial tissue. For a primer pair that spanned transmembrane regions 2–6 of the receptor and was contained wholly in exon 11, a 552–base pair fragment was amplified successfully in 19 of 25 human endometrial samples. Conclusion(s): The traditional gonadal LH/hCG receptor does not appear to be present in human endometrial tissue. The presence of a portion of the transmembrane part of the molecule suggests that human endometrium may express a truncated or variant form of the receptor.
CARLETON P. BARNES, 1903-1962

T weas in the middle of last September that the Washington newspapers carried the sad news that Carleton P. Barnes, age 59, had passed away in the performance of his duties. Dr. Barnes. with his wife, was at that time in Budapest, Hungary, where he was attending the plenary session of the Commission on National Atlases of the International Geographical Union as official representative of the United States. The unexpected passing of Carleton P. Barnes ends a varied, colorful, and successful career. Born in Plainville, Connecticut, he started his formal studies in the Carnegie Institute of Technology in Pittsburgh; he continued his studies at the New York State College of Forestry, Syracuse, and from there transferred to Clark Universitv, Worcester, Massachusetts, where he studied geography under Professor Elmer W. Ekblaw and received the doctorate. After a short vacation he joined the staff of the U.S. Department of Agriculture on August 1. 1929, as Assistant Agricultural Economist. It was at this time that Dr. Barnes and the writer first became acquainted, and a lasting friendship developed that was never clouded bv controversy or bias. One of the first tasks Dr. Barnes undertook in his new post was the preparation of the well-known map defining and describing the "Natural Land-Use Areas of the United States," on a scale of 1: 4,000,000. This map was published by the Bureau of Agricultural Economics. USDA, in 1933, and passed through two editions but is now out of print. Another study of more than casual interest was his comparative economic analysis of land-division patterns for farms, as represented by square and long-lot divisions of the land. "Economics of the Long-lot Farm" appeared in the Ceographical Review. Vol. 25 (1935), pp. 2k301. The results of this study pro'ide guiding principles w.hen new land is divided for settlement. From that time on Dr. Barnes continued to advance in his career. In 1935 he became Senior Agricultural Economist in charge of the Land Classification Unit in the Bureau of Agricultural Economics. In 1937 he became Principal Scientist in Charge of Sunrey Coordination in the Office of Land-Use Coordination. From there he transferred in 1944 to the Soil Surxeyt Division as Chief Analyst of Soil Uses and Productivity. Finally in 1949 he was assigned to the Agricultural Research Advison, Committee staff of the Agricultural Research Service, the position he occupied on September 18, 1962, when he passed away. In this last position he made several valuable contributions to the Yearbook of Agriculture: in the 1955 Yearbook WATER, -What Research Is Doing on Problems of Water in Agriculture"; in the 1957 Yearbook SOIL, -Soil Management in Regions"; and in the 1958 Yearbook LAND, Our Wealth of Land Resources."
Thermal Stratification in the Arctic Ocean

Fine scale measurements of the vertical temperature profile in an Arctic water column show the presence of several cascaded isothermal layers. Layers between the depths of 300 anid 350 meters range from 2 to 10 meters in thickness, while the temperature change between adjacent layers is approximately 0.026 degrees C. The individual layers are isothermal to within +/- 0.001 degrees C.
Wireless Aspects of Telehealth

Telehealth is the use of electronic information and communication technology to deliver health and medical information and services over large and small distances. Broadband wireless services available today, along with more powerful and convenient handheld devices, will enable a transformational change in health management and healthcare with the introduction of real-time monitoring and timely responses to a wide array of patient needs. Further, a network of low-cost sensors and wireless systems help in creating constantly vigilant and pervasive monitoring capability at home and at work. This paper addresses recent efforts in this growing field, including standards, system architectures, propagation models, and lower layer protocols for body area networks. The paper also suggests the use of cooperative transmission-based strategies for such wireless topologies.
Real-time monitoring of matrix acidizing including the effects of diverting agents

Real-time monitoring of the injection rate and pressure during matrix acidizing provides operators with a way to determine the changing skin factor as stimulation proceeds. Current methods are based either on the assumption of steady-state flow in the region around the wellbore affected by acid injection or on computer solution of the transient flow equations describing the unsteady reservoir flow process occurring during acidizing. In this paper, a new method for real-time monitoring of matrix acidizing, the inverse injectivity vs. superposition time function plot, is presented. This new method can be applied with a spreadsheet computer program or a programmable calculator and accounts for the transient flow effects occurring during matrix acidizing at multiple rates and injection pressures. The evolving skin factor during a matrix treatment is readily obtained from the diagnostic plot. Hypothetical examples show how the inverse injectivity plot can be used to assess the efficiency of stimulation and diversion. Comparisons with previously presented field cases show the new method to be a simple and accurate means of monitoring the evolving skin factor during matrix acidizing.
The 24-hour effects of glyburide and chlorpropamide after chronic treatment of type II diabetic patients.

ABSTRACT A single-blind, randomized, comparative evaluation of glyburide * (GL) and chlorpropamide (CP) therapy was performed in twenty previously untreated patients with non-insulin dependent diabetes mellitus (NIDDM) of about two years duration, Only newly diagnosed patients who were never treated and whose fasting blood glucose (FBS) levels were > 140 mg/dl after a six to eight week trial of dietary restriction were evaluated. Metabolic studies were performed before and after four months of therapy. GL and CP produced essentially the same effects on serum levels of glucose, insulin, glucagon (IRG), growth hormone (GH), cholesterol, and triglyceride, The mean 24-hour glucose levels for both the GL and CP groups were significantly lower than the pretherapy values (p 0.05). Excellent control of plasma glucose was possible during the entire day without producing nocturnal hypoglycemia. Neither GL nor CP therapy influenced the mean 24-hour levels of IRG, GH, or cholesterol. However, mean 24-hour levels of triglyceride were lower in both groups. IRG levels were elevated and the pattern of change In the Insulin and IRG levels paralleled each other, which suggested that glucagon may play a role in the resistance of Insulin action in NIDDM. GH levels were normal and remained unchanged during therapy. It was concluded that detailed 24-hour studies are important for better understanding the spectrum of abnormalities In newly diagnosed patients with NIDDM who were never treated. Results of the glucose-insulin interrelationships throughout the day and night indicate that these NIDDM patients appear to have an islet cell impaired glucose/insulin release abnormality as well as a resistance to the action of insulin. Chronic therapy with GL or CP appeared to lower glucose levels by improving Insulin action.
Effect of selective logging on tree and understory regeneration in miombo woodland in western Tanzania

Tree regeneration and understory response to selective cutting of Pterocarpus angolensis DC, and Sterculia quinqueloba Sim, was measured outside Katavi National Park, Tanzania. Contrary to expectations, a selective harvest had no effect on tree recruitment for either species in this miombo woodland. In unlogged plots along transects taken at increasing distance from a main road, the stand densities of young trees declined away from the road. Since anthropogenic activity along the road results in a high fire frequency but low native ungulate densities, the increased rate of tree regeneration near the road may result from either reduced grazing and browsing pressure by native ungulates, or reduced fire intensity and severity along roads. These effects appear to mask any possible effect of selective harvest on tree recruitment. Currently, there is no evidence of compensatory recruitment of trees of any species into the canopy to replace logged trees and this will lead to a gradual thinning in overstory stand density. Resume Introduction
Human Papillomavirus Type 31b E1 and E2 Transcript Expression Correlates with Vegetative Viral Genome Amplification

Human papillomavirus (HPV) genome replication is dependent on the expression of E1 and E2 proteins. The organotypic (raft) culture system was used to investigate changes in viral early gene expression and vegetative genome replication during the complete life cycle of HPV type 31b (HPV31b). We have previously shown the synthesis of HPV31b viral particles as early as 10 days of growth of CIN-612 9E raft tissues (Ozbun, M. A., and Meyers, C. (1997). J. Virol. 71, 5161-5172). In the present study, we investigated the structures and temporal expression levels of HPV31b E1 and E2 transcripts, as well as the replication of the viral genome during the viral life cycle. The amplification state of the HPV31b genome was maximal at 10 days of raft tissue growth. Furthermore, the expression levels of E1 and E2 RNAs correlated with vegetative viral DNA replication. Levels of E1- and E2-specific transcripts were dissimilar throughout the viral life cycle. E2 RNA levels remained relatively constant, whereas E1 RNA levels were upregulated during the maximal amplification of viral genomes and the biosynthesis of virions. These data indicate that E1 may be the major regulator of viral genome amplification in preparation for DNA packaging and virion morphogenesis.
Hydrocarbons in the atmosphere

Trace concentrations of highly reactive hydrocarbons of biogenic origin have been proposed for some time as being important in aerosol formation processes in the atmosphere. More recently, assessments of potential photochemical reactions in the troposphere have proposed a role in the atmospheric ozone cycle for hydrocarbons, even for compounds such as methane that had previously been considered nonreactive. An assessment of the atmospheric hydrocarbon reaction system has been limited by a lack of observational information on the nature of conditions in the remote or non-urban atmosphere. Recent data on terpene concentrations and other biogenic hydrocarbon compounds are presented. Data on ethane and acetylene from aircraft samples taken over the north and south Pacific Ocean show concentrations in the 0.5 to 1 μ/m3 range for ethane and in the 0.05 to 0.3 μg/m3 range for acetylene. A concentration gradient is present for these compounds between the northern and southern hemisphere. A rudimentary global concentration pattern for these C2 compounds has been developed on the basis of recent data.
Regulatory and catalytic domain dynamics of smooth muscle myosin filaments.

Domain dynamics of the chicken gizzard smooth muscle myosin catalytic domain (heavy chain Cys-717) and regulatory domain (regulatory light chain Cys-108) were determined in the absence of nucleotides using saturation-transfer electron paramagnetic resonance. In unphosphorylated synthetic filaments, the effective rotational correlation times, τr, were 24 ± 6 μs and 441 ± 79 μs for the catalytic and regulatory domains, respectively. The corresponding amplitudes of motion were 42 ± 4° and 24 ± 9° as determined from steady-state phosphorescence anisotropy. These results suggest that the two domains have independent mobility due to a hinge between the two domains. Although a similar hinge was observed for skeletal myosin (Adhikari and Fajer (1997) Proc. Natl. Acad. Sci. U.S.A. 94, 9643−9647. Brown et al. (2001) Biochemistry 40, 8283−8291), the latter displayed higher regulatory domain mobility, τr = 40 ± 3 μs, suggesting a smooth muscle specific mechanism of constraining regulatory domain dynamics. In the myos...
Activity of Free and Immobilized Glucose Oxidase: An Electrochemical Study

The activity of free and immobilized glucose oxidase was determined using a sandwich type thin-layer electrochemical cell. The thin-layer cell consisted of a gold electrode deposited on a glass microscope slide, 165 μm thick Teflon TFE spacers, and a glass cover. Enzyme activity was determined by using cyclic voltammetry to measure the amount of hydrogen peroxide produced in the glucose oxidase catalyzed redox reaction between glucose and oxygen in the thin-layer cell. The specific activity of 13.4 nM glucose oxidase in 0.2 M aqueous sodium phosphate, pH 5.2 at room temperature, was calculated to be 4.34 U/mg GOx. Under the same experimental conditions, qualitative detection of the activity of glucose oxidase covalently immobolized to a thin radiofrequency plasma modified poly(etherurethaneurea) film was demonstrated.
Morphology and variability of the Titan ringlet and Huygens ringlet edges

Abstract We present a forward modeling approach for determining, in part, the ring particle spatial distribution in the vicinity of sharp ring or ringlet edges. Synthetic edge occultation profiles are computed based on a two-parameter particle spatial distribution model. One parameter, h , characterizes the vertical extent of the ring and the other, δ , characterizes the radial scale over which the ring optical depth transitions from the background ring value to zero. We compare our synthetic occultation profiles to high resolution stellar occultation light curves observed by the Cassini Ultraviolet Imaging Spectrograph (UVIS) High Speed Photometer (HSP) for occultations by the Titan ringlet and Huygens ringlet edges. More than 100 stellar occultations of the Huygens ringlet and Titan ringlet edges were studied, comprising 343 independent occultation cuts of the edges of these two ringlets. In 237 of these profiles the measured light-curve was fit well with our two-parameter edge model. Of the remaining edge occultations, 69 contained structure that could only be fit with extremely large values of the ring-plane vertical thickness ( h > 1 km) or by adopting a different model for the radial profile of the ring optical depth. An additional 37 could not be fit by our two-parameter model. Certain occultations at low ring-plane incidence angles as well as occultations nearly tangent to the ring edge allow the direct measurement of the radial scale over which the particle packing varies at the edge of the ringlet. In 24 occultations with these particular viewing geometries, we find a wide variation in the radial scale of the edge. We are able to constrain the vertical extent of the rings at the edge to less than ∼300 m in the 70% of the occultations with appropriate viewing geometry, however tighter constraints could not be placed on h due to the weaker sensitivity of the occultation profile to vertical thickness compared to its sensitivity to δ . Many occultations of a single edge could not be fit to a single value of δ , indicating large temporal or azimuthal variability, although the azimuthal variation in δ with respect to the longitudes of various moons in the system did not show any discernible pattern.
Stochastic multiple attribute evaluation of land use policies

Abstract Multiple attribute evaluation (MAE) of management actions is non-stochastic when the outcomes of those actions provide a fixed combination of attributes. Assuming the attributes of outcomes of management actions are non-stochastic and ranking those actions using MAE can lead to an inaccurate ranking when the attributes are stochastic. A stochastic MAE method is proposed for ranking management actions that have outcomes whose attributes are stochastic. The proposed method: (1) identifies possible actions for resolving a management problem; (2) selects and simulates the multiple attributes of the outcomes of possible management actions; (3) determines feasible management actions; (4) estimates attribute weights for different stakeholders; (5) uses stochastic dominance with respect to a function to rank feasible management actions based on the probability distributions of the attributes of outcomes; and (6) resolves conflicts in stakeholders’ preferences for management actions. The proposed stochastic MAE method is demonstrated using a constructed example that uses simulated data to rank land use policies for stakeholders having different preferences for two interdependent attributes of the policy outcomes: buyer satisfaction with the density of residential housing and the percent of the area of interest with high realized habitat for multiple species. The method can be used to rank any set of management actions for which the stochastic attributes of outcomes can be characterized by probability distributions and the other information needed to apply the method is readily obtainable. Use of the method can be simplified by incorporating the various techniques and parameters into a spatial decision support tool.
Factorial versus Typological Models: A Comparison of Methods for Personality Data

This article describes an exploration of the distinction between typological and factorial latent variables in the domain of personality theory. Traditionally, many personality variables have been considered to be factorial in nature, even though there are examples of typological constructs dating back to Hippocrates. Recently, some reconceptualizations of typological constructs have emerged due, in part, to the availability of more rigorous methodological tools for identification of types (or nominal latent traits). These tools include multidimensional item response theory (MIRT) and latent class analysis (LCA). Two studies, involving application of these methods, are discussed in this article. The first study uses data collected using a questionnaire based on the five-factor model (FFM) of personality. The second study is based on data collected to investigate the relationships between technology use and literacy skills. The findings of both studies indicate that, while a clear preference for a factoria...
Porphyria cutanea tarda presenting as cicatricial conjunctivitis.

PURPOSE: To report a case of porphyria cutanea tarda presenting as cicatricial conjunctivitis. DESIGN: Observational study. METHODS: A 31-year-old man presented with bilateral inferior symblepharon, superior tarsal conjunctival scarring and concretions, and recurrent conjunctival and episcleral injection. RESULTS: Four years after initial presentation, the patient developed hepatitis C, and 2 years later blisters on his scalp and hands. Direct immunofluorescence studies of biopsies taken from the palpebral conjunctiva of the right lower lid were negative for cicatricial pemphigoid. A twenty-four hour urine specimen analysis revealed elevated levels of uroporphyrins and polycarboxylated porphyrins, confirming the diagnosis of porphyria cutanea tarda. The patient was treated with repeated phlebotomies and oral hydroxychloroquine, which resulted in a significant decrease in the skin lesions, conjunctival injection, and concretions under the upper lids. CONCLUSIONS: Cicatricial conjunctivitis may be a manifestation of porphyria cutanea tarda.
THE EFFECT OF DIGESTS OF PURE PROTEINS ON CELL PROLIFERATION

1. The pepsin hydrolytic products of the pure proteins, crystalline egg albumin, crystalline edestin, and purified fibrin, are utilized by fibroblasts for their proliferation. It appears, therefore, that the growth of fibroblasts in fibrin digests and in the proteose of Witte's peptone is due to the split products of the protein itself and not to accompanying cellular constituents or other impurities. Preliminary denaturation of the protein, as carried out in these experiments, does not alter the nutritive properties of the digest. 2. The digests of the pure proteins employed are deficient in certain substances and do not meet the entire nutritive requirement of the cells for an unlimited period of time. Some supplementary nutritive substances are present in fresh embryonic heart tissue. This circumstance explains the growth of fibroblasts from fresh embryonic heart in digests which do not promote the growth of a pure strain of fibroblasts. 3. Glycocoll and nucleic acid have been found to supplement the nutritive action of pure protein digests for sarcomatous fibroblasts, and to increase greatly the length of life of the tissues. 4. Vegetable proteins, as well as animal proteins, yield proteolytic products which promote the multiplication of fibroblasts.
Race Differences in Ventricular Remodeling and Function Among College Football Players

Athletic training is associated with increases in ventricular mass and volume. Recent studies have shown that left ventricular mass increases proportionally in white athletes with a mass/volume ratio approaching unity. The objective of this study was to compare the proportionality in ventricular remodeling and ventricular function in black versus white National Collegiate Athletic Association Division I football players. From 2008 to 2011, football players at Stanford University underwent cardiovascular screening with a 12-point history and physical examination, electrocardiography, and focused echocardiography. Compared with white players, black players had on average higher left ventricular mass indexes (77 ± 11 vs 71 ± 11 g/m 2 , p = 0.009), higher mass/volume ratios (1.18 ± 0.16 vs 1.06 ± 0.09 g/ml, p 1.2. Mass/volume ratio was inversely related to early diastolic tissue Doppler velocity e′ (r = −0.50, p
Ribulose diphosphate oxygenase. V. Presence in ribulose diphosphate carboxylase from Rhodospirillum rubrum.

Abstract Ribulose-1,5-diphosphate carboxylase was purified fifteenfold from Rhodospirillum rubrum grown autotrophically under H 2 and CO 2 . There was RuDP oxygenase activity associated with the carboxylase. The oxygenase had maximal activity at pH 9.4. Although these bacterial RuDP oxygenase and carboxylase activities were cold labile, activity could not be restored by treatment at 50° in the presence of Mg ++ and a sulfhydryl reagent, in contrast to results with the enzyme from eukaryotes.
Synthesis and biological evaluation of 2-amino-3-(4-chlorobenzoyl)-4-[N-(substituted) piperazin-1-yl]thiophenes as potent allosteric enhancers of the A1 adenosine receptor.

The synthesis and evaluation of a series of 2-amino-3-(4-chlorobenzoyl)-4-[4-(alkyl/aryl)piperazin-yl]thiophene derivatives as allosteric enhancers of the A1-adenosine receptor are described. The nature of substituents on the phenyl ring tethered to the piperazine seem to exert a fundamental influence on the allosteric enhancer activity, with the 4-chlorophenyl 8f and 4-trifluoromethyl 8j derivatives being the most active compounds in binding (saturation and displacement experiments) and functional cAMP studies.
Adjustment for case mix in comparisons of cesarean delivery rates: university versus community hospitals in Vermont.

Abstract Objective: Our objective was to determine whether case mix model adjustment would help to explain differences in cesarean delivery rates between community and university hospitals. We also wished to define a patient population in which the cesarean delivery rate would be more reflective of individual practice patterns than of obstetric or medical risk. Study Design: Established risk factors for cesarean delivery were identified by retrospective chart review at two community hospitals (designated A and B) and a university hospital. Each delivery was assigned exclusively to 1 of 6 risk categories: (1) multiple gestation, (2) fetal malpresentation, (3) delivery at 2 test and by direct standardization analysis with the university hospital case mix used as the standard population. Results: A total of 5705 delivery reports were reviewed (university hospital, n=4538; hospital A, n=531; hospital B, n=636). The cesarean delivery rates were significantly different between hospitals (university hospital, 16.9%; hospital A, 13.6%; hospital B, 12.0%; P =.002). The distributions of patients in the high-risk group were also significantly different between hospitals (university hospital, 16.8%; hospital A, 5.8%; hospital B, 8.8%; P =.001). The percentage of medically complicated cases in the low risk for cesarean group was significantly higher at the university hospital (university hospital, 16.9%; hospital A, 8.8%; hospital B, 9.8%; P =.001). However, no statistical differences were detected between hospitals in either the observed cesarean delivery rates or the standardized rates for the low-risk groups. Conclusion: The case mix model provides a more accurate method of comparing cesarean delivery rates between community and university hospitals. The low-risk group of patients discriminated in this model represents a population in which the cesarean delivery rate may be more reflective of individual practice patterns than of maternal or fetal risks. (Am J Obstet Gynecol 2000;183:1170-5.)
Non-cholinergic strategies for treating and preventing Alzheimer's disease.

The pathophysiology of Alzheimer's disease is complex and involves several different biochemical pathways. These include defective beta-amyloid (Abeta) protein metabolism, abnormalities of glutamatergic, adrenergic, serotonergic and dopaminergic neurotransmission, and the potential involvement of inflammatory, oxidative and hormonal pathways. Consequently, these pathways are all potential targets for Alzheimer's disease treatment and prevention strategies. Currently, the mainstay treatments for Alzheimer's disease are the cholinesterase inhibitors, which increase the availability of acetylcholine at cholinergic synapses. Since the cholinesterase inhibitors confer only modest benefits, additional non-cholinergic Alzheimer's disease therapies are urgently needed. Several non-cholinergic agents are currently under development for the treatment and/or prevention of Alzheimer's disease. These include anti-amyloid strategies (e.g. immunisation, aggregation inhibitors, secretase inhibitors), transition metal chelators (e.g. clioquinol), growth factors, hormones (e.g. estradiol), herbs (e.g. Ginkgo biloba), nonsteroidal anti-inflammatory drugs (NSAIDs, e.g. indomethacin), antioxidants, lipid-lowering agents, antihypertensives, selective phosphodiesterase inhibitors, vitamins (E, B12, B6, folic acid) and agents that target neurotransmitter or neuropeptide alterations. Neurotransmitter receptor-based approaches include agents that modulate certain receptors (e.g. nicotinic, muscarinic, alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid [AMPA], gamma-aminobutyric acid [GABA], N-methyl-D-aspartate [NMDA]) and agents that increase the availability of neurotransmitters (e.g. noradrenergic reuptake inhibitors). Of these strategies, the NMDA receptor antagonist memantine is in the most advanced stage of development in the US and is already approved in Europe as the first treatment for moderately severe to severe Alzheimer's disease. Memantine is proposed to counteract cellular damage due to pathological activation of NMDA receptors by glutamate. Results with Ginkgo biloba have been mixed. Data for neurotrophic therapies and vitamin E (tocopherol) appear promising but require confirmation. NSAIDs and conjugated estrogens have not proven to be of value to date for the treatment of Alzheimer's disease. Statins may have a potential role in reducing the risk or delaying the onset of Alzheimer's disease, although this has yet to be confirmed in randomised trials. There are currently no data to support the use of statins as a treatment for dementia. This article provides an update on the current status of selected agents, focusing primarily on those agents with the most extensive clinical evidence at present.
Conceptual and Methodological Problems in Research on College Undermatch

Access to the nation’s most selective colleges remains starkly unequal, with students in the lowest income quartile constituting less than 4% of enrollment. A popular explanation for this phenomenon is that low-income students undermatch by attending less selective colleges when their credentials predict admission to more highly selective colleges. We identify three problematic assumptions in research on undermatching: (a) that researchers can differentiate colleges at the “margin that matters” for student outcomes; (b) that researchers can accurately predict who will be admitted at colleges that use holistic admission processes; and (c) that using achievement measures like SAT (Scholastic Assessment Test) scores to match students to colleges will reduce postsecondary inequality. We discuss the implications of these assumptions for future research on college choice and stratification.
Thermostability characteristics of glucosephosphate and triosephosphate isomerase in erythrocytes from several species

Significant differences in the thermostability of both glucosephosphate and triosephosphate isomerase were noted among a series of six primate and five nonprimate species. The enzyme structural differences among species, as assessed by thermostability profiling, was greater than expected from electrophoretic mobility patterns. Microheterogeneity of GPI, i.e. differences in thermostability within a species that are not detectable by electrophoresis, was detected in two primate species. Major differences in the levels of erythrocyte enzyme activity were observed with human and cow differing by 18-fold for TPI and baboon and cow differing by seven-fold in GPI activity.
Oteoporosis: The importance of maintainig good bone health

Osteoporosis will affect 50% of women and 20% of all men during their lifetime. This article explains how to maintain bone health and how osteoporosis is diagnosed and treated.
Comparison of PBDE congeners as inducers of oxidative stress in zebrafish

A proposed primary pathway through which polybrominated diphenyl ethers (PBDEs) disrupt normal biological functions is oxidative stress. In the present study, 4 PBDE congeners were evaluated for their potential to initiate oxidative stress in zebrafish during development: BDE 28, BDE 47, BDE 99, and BDE 100. N-acetylcysteine (NAC) was used to increase intracellular glutathione concentrations and only decreased the effects of BDE 28 at 10 ppm and 20 ppm and BDE 47 at 20 ppm. N-acetylcysteine coexposure did not alter the rates of mortality or curved body axis compared with PBDE exposure alone. The activity of glutathione-S-transferase (GST) was not altered at 24 h postfertilization (hpf), but increased following 10 ppm BDE 28 exposure at 120 hpf. Transcription of several genes associated with stress was also evaluated. At 24 hpf, cytochrome c oxidase subunit 6a (COX6a) transcription was up-regulated in embryos exposed to BDE 99, and BDE 28 exposure up-regulated the transcription of Glutathione-S-transferase-pi (GSTpi). At 24 hpf, glutamate-cysteine ligase (GCLC) was slightly down-regulated by all congeners evaluated. At 120 hpf, TNF receptor-associated protein 1 (TRAP1) and COX6A were up-regulated by all congeners, however GSTpi was down-regulated by all congeners. The results of quantitative real-time transcription polymerase chain reaction are mixed and do not strongly support a transcriptional response to oxidative stress. According to the authors' data, PBDEs do not induce oxidative stress. Oxidative stress may occur at high exposure concentrations; however, this does not appear to be a primary mechanism of action for the PBDE congeners tested.
Mentors and Protégés: A Critical Review of the Literature:

Within the last few years, mentoring has emerged as a popular topic in several fields. Articles and talk shows imply that success in life is somehow related to having a mentor or being a mentor. The purpose of this review is to evaluate the extent to which such enthusiasm can be substantiated by research. The literature on mentoring is divided into three sections: the mentoring phenomenon in adult growth and development, mentoring in the business world, and mentoring in academic settings. A concluding section summarizes findings across these three settings, speculates about the relevance of mentoring for adult educators, and suggests avenues for future inquiry.
Light-Quark Spectroscopy from Charmonium Decay

Hadron phenomenology inspired by quantum chromodynamics (QCD) has made great progress in explaining, in a semi-quantitative way, the spectroscopy and decay rates of mesons containing heavy (b, c) quarks. Light (u, d, s) quark spectroscopy was vital for the early successes of the SU6 quark model; these early successes were, however, never permitted to grow into a quantitatively descriptive, much less a predictive, theory of light quarks and antiquarks bound together by gluons, in a rigorous QCD framework. In the present lecture, we restrict ourselves to meson spectroscopy in the low-mass region ≲ 2.2 GeV/c2, and to the attempts to understand their mass and symmetry structure. We point up some particularly vexing open questions and problems. We then review the information that has recently become available from heavy quarkonium (mainly charmonium) decays into light-quark-based mesons. It turns out that these decays, observable largely in the center-of-mass frame, with large counting rates and low multiplicities, are able to permit valuable insights into the quark content and symmetry structure of this regime of u, d, s-based mesons. The lecture is organized as follows: 2. Open questions in the lowest-mass \( q\bar{q} \) nonets. 3. The use of charmonium decays to define projection operators of quark content and symmetry structure. 4. Information available from hadronic and radiative \( c\bar{c} \) decays: a case-by-case review. 5. Do gluonia show up in radiative decays? 6. Exotic candidates: do \( c\bar{c} \) decays have unique information to contribute? 7. A score sheet.
Origin-destination flow measurement in high-speed networks

An origin-destination (OD) flow between two routers is the set of packets that pass both routers in a network. Measuring the sizes of OD flows is important to many network management applications such as capacity planning, traffic engineering, anomaly detection, and network reliability analysis. Measurement efficiency and accuracy are two main technical challenges. In terms of efficiency, we want to minimize per-packet processing overhead to accommodate future routers that have extremely high packet rates. In terms of accuracy, we want to generate precise measurement results with small bias and standard deviation. To meet these challenges, we design a new measurement method that employs a compact data structure for packet information storage and uses a novel statistical inference approach for OD-flow size estimation. We perform simulations to demonstrate the effectiveness of our method.
The Market Makers: How Leading Companies Create and Win Markets

The article reviews the book “The Market Makers: How Leading Companies Create and Win Markets,” by Daniel F. Spulber.
A Process Model of Family Economic Pressure and Early Adolescent Alcohol Use

This study examines the utility of a process model which links economic pressure and adolescent use of alcohol in a sample of 76 rural families from a midwestern state. A series of path analyses trace the empirical relations from perceived economic problems through parents' feelings of depression/hostility and their observed hostile/irritable behaviors to the problematic use of alcohol and the antisocial behavior of early adolescents. The findings suggest that parental hostility directed toward children is associated with adolescent antisocial behavior through a process of social learning that leads to deviant friends and alcohol use. Conflict in the marriage is directly related to adolescent drinking as a possible coping response to family stress and, perhaps, through the disruption of parents' ability to function as effective agents of social control.
Tanycytes in the sunfish brain : NADPH-diaphorase histochemistry and regional distribution

NADPH-diaphorase histochemistry has been shown to be a useful method for identifying cells that synthesize and release nitric oxide, which is implicated in the modulation of a variety of neural functions, including synaptic transmission, cerebral blood flow, and excitotoxicity. In the sunfish brain, NADPH-diaphorase histochemistry stains tanycytes specifically and almost exclusively, allowing for a thorough examination of the morphology and distribution of this type of cell. Tanycytes are nonciliated, process-bearing ependymal and extraependymal cells that contact the ventricular surface via apical processes, and the pial surface via basal processes. Ependymal tanycytes are located at the ventricular surface, and project basal processes into the parenchyma of the brain. Extraependymal tanycytes are found away from the ventricular matrix. Some extraependymal tanycytes are small, bipolar, and tend to be associated with bundles of basal processes. Isolated extraependymal tanycytes are larger, darkly stained, and multipolar. Their basal processes terminate in specialized endfeet on blood vessels, neuronal somata, or the pial surface. Specialized types of tanycytes are found in the optic tectum, the epineurial septum between axonal bundles along the midline in the medulla, and in restricted regions on the pial surface in the medulla. The only NADPH-diaphorase-positive neurons are found in the commissural nucleus of area ventralis telencephali. Injection of horseradish peroxidase into the ventricles shows that tanycytes lining the third and fourth ventricles are capable of taking up the tracer and transporting it into their basal processes. Tanycytes are unevenly distributed in the brain. There is a rough rostrocaudal gradient of cell density: tanycytes are sparse in the telencephalon and dense in the isthmus and medulla, although cell density is low in the spinal cord. Not all ventricular linings contain tanycytes: cell density is low in the medial ventricle of the telencephalon and in the infundibular recess, and high along the fourth ventricle. The function of tanycytes in the sunfish is not known. The association of tanycytes with both the ventricles and blood vessels raises the possibility that they play some role in sampling the biochemical constituents of both compartments and communicating the information to neural elements. It is proposed that tanycytes react to the biochemical composition in the ventrile and plasma by increasing or decreasing nitric oxide synthesis and release, which in turn influence neuronal activity or cerebral blood flow. © 1993 Wiley-Liss, Inc.
Co-regulation of a large and rapidly evolving repertoire of odorant receptor genes

The olfactory system meets niche- and species-specific demands by an accelerated evolution of its odorant receptor repertoires. In this review, we describe evolutionary processes that have shaped olfactory and vomeronasal receptor gene families in vertebrate genomes. We emphasize three important periods in the evolution of the olfactory system evident by comparative genomics: the adaptation to land in amphibian ancestors, the decline of olfaction in primates, and the delineation of putative pheromone receptors concurrent with rodent speciation. The rapid evolution of odorant receptor genes, the sheer size of the repertoire, as well as their wide distribution in the genome, presents a developmental challenge: how are these ever-changing odorant receptor repertoires coordinated within the olfactory system? A central organizing principle in olfaction is the specialization of sensory neurons resulting from each sensory neuron expressing only ~one odorant receptor allele. In this review, we also discuss this mutually exclusive expression of odorant receptor genes. We have considered several models to account for co-regulation of odorant receptor repertoires, as well as discussed a new hypothesis that invokes important epigenetic properties of the system.
Light Through Darkness: The Ideal of Human Perfection in the Zohar

One of the perennial, and more vexing, problems in religious thought and philosophy has been the question unde malum. In ancient, medieval, and modern thought, the issue has been viewed mostly in its theological context. From the perspective of traditional monotheistic theology, the problem thus presents itself: If God is truly all good and all powerful, then why would God cause or even allow evil, whether natural (e.g., earthquakes, floods, human disease) or moral (murder, rape, and the like), to exist? Inasmuch as the existence of evil, at least from the phenomenological point of view, is an indisputable fact, it would seem that either divine omnipotence or benevolence must be limited.
Living on the edge: residential property values in the urban-rural interface.

This study estimates the contribution of both urban-rural fringe location and lake proximity on residential property values in three upstate counties of South Carolina through estimation of spatial hedonic housing price models. Location in the urban fringe and the urban-rural interface are found to have a positive impact on residential housing values relative to either urban or more rural locations. Lakes in the upstate contribute positively to housing values to the extent that the house has a view of a lake, lake access, or lake frontage.