cssi/SciSciGPT-SciSciNet huggingface dataset:
Transition State Studies on the Dioxirane-Mediated Asymmetric Epoxidation via Kinetic Resolution and Desymmetrization

This paper describes an efficient kinetic resolution process of trisubstituted cyclic olefins via a chiral dioxirane generated in situ from a fructose-derived ketone and Oxone. The substrates presented include a variety of 1,3-disubstituted and 1,6-disubstituted cyclohexenes with the stereogenic centers at allylic positions. A sequential desymmetrization and kinetic resolution of 1,4-cyclohexadienes by the chiral dioxirane was also found to be feasible. The initially formed monoepoxides can be kinetically resolved by continuing the reaction, leading to the increase or decrease of the ee values of monoepoxides depending on the diene systems. In some cases, a prochiral directing group is not required and the first formed epoxide stereoselectively directs the second epoxidation. When the coupled desymmetrization and kinetic resolution is used synergistically, high enantiopurity can be obtained for an epoxide from an intrinsically less enantioselective substrate. The observed absolute and relative stereochemistry as well as the changing optical purity can be effectively rationalized by transition state analysis.
Statins Do Not Significantly Affect Muscle Sympathetic Nerve Activity in Humans With Nonischemic Heart Failure: A Double-Blind Placebo-Controlled Trial

Abstract Background Hydroxymethylglutaryl–coenzyme A reductase inhibitors (statins) have been shown to reduce sympathetic nervous system (SNS) activation in experimental heart failure (HF). However, this potential mechanism of action of statins in HF has not been well studied in humans. Methods and Results Twenty-six patients with nonischemic systolic HF (left ventricular ejection fraction [LVEF] ≤35%) were randomized to atorvastatin (10 mg) or placebo for 3 months. Pre- and posttreatment testing included echocardiography, laboratory assays, quality of life (QOL) questionnaires, and peroneal nerve muscle sympathetic nerve activity (MSNA) via microneurography. Eighteen subjects had technically adequate MSNA tracings before and after treatment. The cohort was 65% male, 81% New York Heart Association functional class II, LVEF 26 ± 6%, and low-density lipoprotein cholesterol (LDL-C) 108 ± 26 mg/dL. Baseline MSNA was 41 ± 2 bursts/min. LDL-C significantly decreased in the atorvastatin (−36.8%) versus the placebo (−0.1%) group (P Conclusions Short-term statin therapy in patients with nonischemic HF does not result in a significant decrease in SNS activation as measured by MSNA. These findings are consistent with the neutral outcomes of large clinical trials of statins in HF.
Creating a Process for Capturing and Leveraging Intellectual Capital

This article introduces an example project to describe a process with a practical mechanism to capture and disseminate intellectual capital in an organization. Five phases of the process are described for the example project: needs analysis, design process, development process, evaluation, and performance environment. A knowledge-base is used as the practical mechanism for capturing the expertise of individuals and making it available to other members of the organization. The knowledge-base grows as members of the organization solve new problems and enter that expertise into the knowledge-base. Productivity increases as members consult the knowledge-base and reuse solutions that were developed by other members of the organization. The article concludes by noting that the technology plays an important role in automating the capture and retrieval of knowledge, but a ehange in the belief structure of the members of the organization is essential to sucessfully utilize the knowledge-base for capturing and disseminating intellectual capital.
Feasibility of real-time transcription in the clinical setting

This study evaluated a computer-based approach to transcription in the clinical setting: transcription done in real time. Real-time transcription entails orthographically transcribing the language produced by a child, using a computer and a standard transcription format, while the child is engaged in a conversation. Twenty-minute language samples from 20 preschool children were transcribed both in real time and from au diotape and compared on several quantitative measures of language production. On average, 90% of the words and utterances transcribed from audiotape were captured in real time, with there being no significant differences in either intelligibility or MLU between the two transcription methods.
Microinstabilities in a 10-Kilowatt Self-Field Magnetoplasmadynamic Thruster

Abstract : Theoretical studies indicate that a variety of microscopic and macroscopic plasma instabilities can significantly affect the performance of the magnetoplasmadynamic (MPD) thruster, yet experimental evidence for their existence is extremely limited. The objective of this research was to provide experimental evidence for the existence of microinstabilities in a 10-kW-class, self-field MPD thruster. The lower- bound of the range of thruster operating currents investigated in this study was set by the requirement that the electromagnetic thrust component be much greater than the electrothermal thrust component. The upper-bound of the operating current was set by the initial observation of high-frequency thruster voltage oscillations, which is usually associated with the onset of excessive thruster erosion. Experimental evidence for two microinstabilities was obtained in the near-field plume of the thruster: 1) the generalized lower hybrid drift instability and 2) the electron cyclotron drift instability.
Structure of the carboxy-terminal region of a KCNH channel.

The KCNH family of ion channels, comprising ether-a-go-go (EAG), EAG-related gene (ERG), and EAG-like (ELK) K(+)-channel subfamilies, is crucial for repolarization of the cardiac action potential, regulation of neuronal excitability and proliferation of tumour cells. The carboxy-terminal region of KCNH channels contains a cyclic-nucleotide-binding homology domain (CNBHD) and C-linker that couples the CNBHD to the pore. The C-linker/CNBHD is essential for proper function and trafficking of ion channels in the KCNH family. However, despite the importance of the C-linker/CNBHD for the function of KCNH channels, the structural basis of ion-channel regulation by the C-linker/CNBHD is unknown. Here we report the crystal structure of the C-linker/CNBHD of zebrafish ELK channels at 2.2-A resolution. Although the overall structure of the C-linker/CNBHD of ELK channels is similar to the cyclic-nucleotide-binding domain (CNBD) structure of the related hyperpolarization-activated cyclic-nucleotide-modulated (HCN) channels, there are marked differences. Unlike the CNBD of HCN, the CNBHD of ELK displays a negatively charged electrostatic profile that explains the lack of binding and regulation of KCNH channels by cyclic nucleotides. Instead of cyclic nucleotide, the binding pocket is occupied by a short β-strand. Mutations of the β-strand shift the voltage dependence of activation to more depolarized voltages, implicating the β-strand as an intrinsic ligand for the CNBHD of ELK channels. In both ELK and HCN channels the C-linker is the site of virtually all of the intersubunit interactions in the C-terminal region. However, in the zebrafish ELK structure there is a reorientation in the C-linker so that the subunits form dimers instead of tetramers, as observed in HCN channels. These results provide a structural framework for understanding the regulation of ion channels in the KCNH family by the C-linker/CNBHD and may guide the design of specific drugs.
Alteration of the electron-capture detector response to polycyclic aromatic hydrocarbons by oxygen doping of the carrier gas

Abstract A constant-current electron-capture detector (ECD) has been used to study the effects of oxygen added intentionally to the carrier gas on the response of the instrument to five polycyclic aromatic hydrocarbons (PAHs). At a detector temperature of 250°C the responses of anthracene, pyrene and 1,2-benzanthracene are increased very substantially, while those of phenanthrene and tetracene are increased only slightly. The basis of these observations is discussed, and mass spectrometric measurements of the negative ions formed in an ECD as a result of oxygen doping are reported. It is suggested that the structure-dependent oxygen-caused response enhancements observed for PAH molecules might assist in the identification of these in their analysis by gas chromatography.
Acquisition of physician group practices by for-profit and not-for-profit organizations

Abstract This exploratory study examines the acquisition and formation of physician group practices by for-profit and not-for-profit organizations from a strategic management perspective. Data sources include the 1991 and 1995 AMA Census of Medical Groups, the 1991 and 1995 InterStudy Census of HMOs, and the 1991 and 1995 AHA Annual Surveys . Longitudinal and cross-sectional logistic regressions are used to conduct the hypothesis tests. The data suggest that economies of scope in physician practice is a leading attribute in the selection of acquisition targets. Whereas transitions to not-for-profit ownership were associated with both target attributes and local market characteristics influencing physicians to sell, for-profit acquisition of group practices was predicted solely by target attributes. The paper concludes by suggesting several potentially fruitful directions for future studies.
Role of Organic Debris Dams in Regulating the Export of Dissolved and Particulate Matter from a Forested Watershed

An organic debris dam is an accumulation of organic matter in a stream which obstructs water flow. Debris dams trap sediments in the pool formed upstream from them and the dam structure itself collects particulate organic matter. This study was done at the Hubbard Brook Experimental Forest, in New Hampshire, to examine the relative importance of these structures in retention of sediment and organic matter in a small stream ecosystem. An experimental approach was used in which all organic debris dams were re- moved from a 175-m section of second-order stream, just above a gauging weir. The material being exported from the watershed was separated into three size categories: dissolved matter ( 1 mm). Export of each size fraction was monitored for at least 1 yr prior to dam removal, and for 1 yr following removal. Following dam removal, export of dissolved matter increased slightly due to an increase in the concentration of dissolved organic carbon in the stream water during periods of high discharge. Fine particulate matter export increased dramatically at high discharges following dam removal; concen- trations in some instances achieved values five times higher than any observed before dam removal. Coarse particulate matter export also was greatly increased. Calculating dissolved matter and particulate matter export from the watershed, with and without organic debris dams, showed that dam removal brought about a 6% increase in the export of dissolved matter and a 500% increase in the export of both fine particulate and coarse particulate matter.
Expression of vascular permeability factor (vascular endothelial growth factor) and its receptors in endometrial carcinoma.

BACKGROUND Solid tumors, including endometrial carcinomas, must induce a vascular stroma to grow beyond a minimal size. The mechanisms responsible for angiogenesis in endometrial carcinoma, however, are not well defined. Vascular permeability factor (VPF), also known as vascular endothelial growth factor (VEGF), is a multifunctional cytokine that is an important regulator of tumor angiogenesis. We evaluated VPF/VEGF mRNA and protein expression, as well as VPF/VEGF receptor mRNA expression, in endometrial carcinoma. METHODS Fourteen examples of endometrial carcinoma were evaluated by in situ hybridization; in 7 cases, benign atrophic endometrium from the same patient was also examined. Histologic sections were subjected to in situ hybridization using 35S-labeled riboprobes specific for VPF/VEGF and, in a subset of cases, riboprobes specific for the VPF/VEGF receptors flt-1 and KDR. In addition, ten examples of endometrial carcinoma were evaluated for VPF/VEGF protein expression by immunohistochemistry. RESULTS All 14 examples of endometrial carcinoma studied by in situ hybridization exhibited focal strong VPF/VEGF mRNA expression by tumor cells. In addition, the endothelial cells of surrounding microvessels strongly expressed flt-1 and KDR mRNAs in all ten cases examined. In contrast, no strong expression of VPF/VEGF, flt-1, or KDR mRNA was observed in the seven examples of benign atrophic endometrium studied. All ten cases of endometrial carcinoma studied by immunohistochemistry exhibited strong VPF/VEGF protein expression by tumor cells. CONCLUSIONS These observations suggest that VPF/VEGF is an important angiogenic factor in endometrial carcinoma. Cancer 1996;78:454-60.
Analysis of the channel inversion layer capacitance in the very thin-gate IGFET

As the gate insulator thickness approaches the channel thickness, the gate capacitance is speculated to be smaller than its gate insulator capacitance. The gate capacitance of the thin-gate IGFET is calculated using Maxwell-Boltzmann and Fermi-Dirac statistics and is experimentally measured. The results show that the gate capacitance approaches the gate insulator capacitance regardless of the gate thickness within the practical range ( T_{ox} > 50 A). To explain why the channel thickness is not reflected in the measured gate capacitance, the channel inversion layer capacitance is analyzed numerically. Based on that, its effects on the gate capacitance are discussed quantitatively and an equivalent circuit is proposed.
Manifold Conjugation and Discrete Gear Design

This paper presents a new conjugation theory and a new design methodology for the advanced conjugation design based on CAD (computer aided design) and CAE (computer aided engineering). A general conjugation theory called manifold conjugation is established based on the classic conjugation theory and manifold theory. It leads to both smooth conjugation modeling and discrete conjugation modeling. The former one has been studied in the previous work for design optimization of analytical conjugation properties. The latter one is a desirable methodology for the conjugation design based on CAE simulation. The paper brings up a new perspective towards conjugation representation theory, leading to a new design process. Contrary to the traditional idea that CAD has to be known before and separated from CAE, the new theory suggests using discrete manifold to bridge CAD and CAE. Furthermore, discrete modeling techniques from CG (computer graphics) such as subdivision can be employed for conjugation modeling and design. Two planar examples that minimize gear PPTE (peak to peak transmission error) show that the methodology is capable of and effective in conjugation optimization.Copyright © 2013 by ASME
Fabrication of black hierarchical TiO2 nanostructures with enhanced photocatalytic activity

Here, we report the fabrication of hierarchical TiO2 nanostructures with wire-in-tube architectures by hydrothermal treatment of anodic TiO2 nanotubes. The mechanism for this morphological evolution was understood by dissolution-precipitation of TiO62− octahedra. Sintering the hierarchical TiO2 nanostructures under vacuum condition created black TiO2 nanostructures, which show anatase phase with self-doped Ti3+ present in the bulk. Due to the reduced band gap, increased donor density, and enlarged active interface, the black hierarchical TiO2 nanostructures demonstrated efficient photocatalytic performance under both full spectrum and visible light illumination.
Elementary excitations of solid ortho-hydrogen diluted with para-hydrogen

The elementary librational excitations of solid molecular hydrogen are calculated using the recursion method of Haydock. This method permits a correct treatment of the problem of dilution with para-hydrogen. Agreement is obtained with previous calculations of the excitations of pure ortho-hydrogen. It is found that the gap in the single-excitation density of states decreases much faster than the ortho concentration. The specific heat and the NMR line shapes and relaxation times are calculated and compared with experimental data. For ortho concentration less than 0.5, the data suggest the existence of excitations with energies several times smaller than those of the collective librations we consider.
Mineralogical and chemical evolution of a rare-element granite-pegmatite system: Harney Peak Granite, Black Hills, South Dakota

Abstract The Harney Peak Granite (1.7 b.y.) in the Black Hills, South Dakota, is a well-exposed granite complex surrounded by a rare-element pegmatite field (barren to Nb-, Ta-, Be, Li-enriched pegmatites). It consists of a multitude of large and small sills and dikes, which exhibit great variation in texture, mineralogy and geochemistry. This granite is moderately to strongly peraluminous with the following mineralogy: plagioclase (An0–An21) + potassium feldspar (Or70–96) + quartz + muscovite ± apatite ± biotite ± garnet ± tourmaline. The granitic intrusions in the interior of the complex have similar K Rb ratios (> 190), whereas this ratio decreases and is more variable for intrusions which are structurally higher or along the perimeter of the complex. Substitutions of (Fe, Mn)Mg−1 in the ferromagnesian minerals, NaCa−1 in plagioclase and RbK−1 in muscovite and potassium feldspar increase in the perimeter granites and vary systematically with K Rb . These more evolved intrusions are commonly enriched in incompatible elements such as Nb, Li, Cs, Be, and B and depleted in Ba, Ca, and Sr relative to the interior, primitive granites. Biotite-bearing assemblages are common in the interior granites but are replaced by tourmaline-bearing granites in the more evolved intrusions. A series of discontinuous reactions may explain this assemblage transition. Observations and trace element modeling suggest that: (1) within individual units volatile transfer mechanisms have resulted in mineral and chemical segregation; (2) 75–80% fractional crystallization of a primitive biotite-muscovite granite was the dominant mechanism in producing the more evolved tourmaline-bearing granites; and (3) extreme fractional crystallization aided by high volatile activity produced the associated rare-element pegmatites.
“I Kissed A Girl”: Heterosexual Women Who Report Same-Sex Kissing (and More)

In this study, analysis of survey data from 436 self-identified heterosexual females from two southeastern universities reveals that almost half (47.9%) reported having kissed another woman out of ...
Rapid-acting glutamatergic antidepressants: the path to ketamine and beyond.

Traditional antidepressants require many weeks to reveal their therapeutic effects. However, the widely replicated observation that a single subanesthetic dose of the N -methyl-D-aspartate glutamate receptor antagonist ketamine produced meaningful clinical improvement within hours, suggested that rapid-acting antidepressants might be possible. The ketamine studies stimulated a new generation of basic antidepressant research that identified new neural signaling mechanisms in antidepressant response and provided a conceptual framework linking a group of novel antidepressant mechanisms. This article presents the path that led to the testing of ketamine, considers its promise as an antidepressant, and reviews novel treatment mechanisms that are emerging from this line of research.
Separation of dead and live mouse spermatozoa.

Abstract A modified glass bead column technique is described for separating live from dead mouse spermatozoa. The technique allows one to separate either epididymal or vasa deferentia cells into three fractions: broken spermatozoa and cellular debris; predominantly live spermatozoa; predominantly dead spermatozoa and contaminant cells. This separation method can facilitate those studies which require the initial use of live populations of spermatozoa.
MCFlow: A Real-Time Multi-core Aware Middleware for Dependent Task Graphs

Driven by the evolution of modern computer architectures from uni-processor to multi-core platforms, there is an increasing need to provide light-weight, efficient, and predictable support for fine-grained parallel and distributed execution of soft real-time tasks with end-to-end timing constraints, modeled as directed a cyclic graphs whose edges capture dependences among their subtasks. At the same time, there is a need to support state of the art programming models such as distributed components, whose ability to encapsulate functionality and allow context-specific optimizations is essential to manage the increasing complexity of modern distributed real-time and embedded systems and systems-of-systems. Real-time distributed middleware such as RT-CORBA has not kept pace with these developments, and a new generation of middleware is needed that can map these dependent subtask graphs onto distributed hosts with multi-core architectures, efficiently and within a simple, lightweight, and intuitive component programming model. To overcome these limitations, we have designed and implemented MC Flow, a novel distributed real-time component middleware for dependent subtask graphs running on multi-core platforms. MC Flow provides three new contributions to the state of the art in real-time component middleware: (1) a very lightweight component model that facilitates system integration and deployment through automatic code generation at compile time from a deployment plan specification, (2) transparent optimization of inter-component communication, and (3) the use of interface polymorphism to separate functional correctness from data copying and other performance constraints so that they can be configured and enforced independently but in a type-safe manner. Empirical evaluations of our approach in comparison to the widely used TAO real-time middleware show that MC Flow performs comparably to TAO when only one core is used and outperforms TAO when multiple cores are involved.
Determination of sulfur in steels by radiochemical neutron activation analysis with liquid scintillation counting

A method has been developed for the determination of low-level sulfur in steels by radiochemical neutron activation analysis. During sample irradiation, 35S is produced by the 34S(n,γ)35S reaction. Irradiated steels are mixed with sulfur carrier and dissolved in HCl/HNO3. Sulfur is reduced to H2S by reaction with HI/H3PO2/HCl. The evolved H2S is absorbed in dilute NaOH, which is mixed with scintillation cocktail for the measurement of 35S by liquid scintillation counting. Sulfur carrier yield is determined by iodometric titration. Chlorine is also determined by RNAA in order to correct for 35S produced via the 35Cl(n,p)35S reaction. Sulfur has been determined at mass fractions as low as ≈5 mg/kg in ultra-high-purity iron using this method.
Generalized varying coefficient models for longitudinal data

SUMMARY We propose a generalization of the varying coefficient model for longitudinal data to cases where not only current but also recent past values of the predictor process affect current response. More precisely, the targeted regression coefficient functions of the proposed model have sliding window supports around current time t. A variant of a recently proposed two-step estimation method for varying coefficient models is proposed for estimation in the context of these gener alized varying coefficient models, and is found to lead to improvements, especially for the case of additive measurement errors in both response and predictors. The proposed methodology for estimation and inference is also applicable for the case of additive measurement error in the com mon versions of varying coefficient models that relate only current observations of predictor and response processes to each other. Asymptotic distributions of the proposed estimators are derived, and the model is applied to the problem of predicting protein concentrations in a longitudinal study. Simulation studies demonstrate the efficacy of the proposed estimation procedure.
The Need for Professionally Oriented ESL Instruction in the United States

Increasing numbers of foreign students are coming to the United States for university-level studies. Most go on to professional careers where English is needed for sophisticated and complex uses. Unfortunately, these students and professionals seldom receive English language training adequate for this purpose, either in school or on the job. Using engineering as a case in point, this article argues that there is a growing need for professionally oriented ESL instruction in American colleges, universities, and companies. Such instruction should combine aspects of both ESL and ESP in what is here called “generalized ESP.” Two illustrations of this approach—technical communication courses for university students and troubleshooting for technical professionals—are discussed. Since World War II, increasing numbers of foreign students (FSs) have been coming to the United States to pursue university studies. FS enrollments during this time have grown at an average annual rate of more than 10%; at last count (1982-83), it stood at 336,990 (Scully 1983). The American Council of Education’s (ACE) Committee on Foreign Students and International Policy, as recently as two years ago, predicted enrollments of more than one million FSs in American colleges and universities by the early 1990s (Scully 1981). Although the rate of enrollment has slowed since then, it still appears likely that the one million mark will be reached before the turn of the century. Most of these students have studied English for many years and have received satisfactory scores on the TOEFL, Michigan Test, or some other test of English proficiency. Nevertheless, their English is often quite weak, especially in the productive skills. Most FSa are
Geological Responses to Urbanization of the Naples Bay Estuarine System, Southwestern Florida, USA

The Naples–Dollar Bay Estuarine System (NDBES), situated in southwestern Florida, has undergone extensive modifications caused directly and indirectly by anthropogenic influences. These alterations include: (1) the substitution of mangrove-forested shorelines with concrete bulkheads and installation of residential canals; (2) installation of a regionally extensive navigational channel; and (3) canalization of the watershed, resulting in annexation of a heavily altered drainage basin ten times the size of the pre-alteration basin and with a significantly different soil and bedrock. The NDBES consists of northern Naples Bay, southern Naples Bay, and Dollar Bay, whose shorelines range from highly developed to undeveloped, respectively. This project explored the geological response of the system to these alterations using data from side-scan sonar, sediment grab samples, and vibracores. In highly urbanized northern Naples Bay, benthic substrates consist primarily of muddy sand with few oyster reefs. Southern Naples Bay and Dollar Bay, however, consist of coarser sediment, and are characterized by extensive mangrove shorelines and numerous fringing oyster reefs. The impact of anthropogenic alterations has significantly shifted sediment distributions in northern Naples Bay from a relatively coarser to a relatively fine grained substrate; to a lesser degree in southern Naples Bay, and Dollar Bay, this transition has not taken place due to the general lack of anthropogenic modifications made to this part of the system.
Reinnervation of distal sensory nerve environments by regenerating sensory axons

This study investigated the specificity of sensory nerve regeneration in a primate model. In adult cynomolgus monkeys, the femoral nerve was explored in the groin and two sensory branches identified. A sensory branch was sectioned and introduced into the proximal channel of a Y-shaped silicone chamber. This proximal sensory nerve stump was given distal choices of distal sensory nerve graft or distal sensory nerve which was intact to the distal sensory cutaneous receptors. After eight months, histological analysis confirmed axonal growth directed towards both the distal nerve graft and the distal nerve intact to the distal cutaneous receptors. However, the number of nerve fibres directed towards the distal nerve was significantly greater than the number of nerve fibres directed towards the nerve graft (P less than 0.004). These results suggest that while both distal nerve graft and distal intact nerve act as specific targets to regenerating proximal primate nerve, the presence of an intact distal end-organ positively enhances sensory regeneration.
Struma lymphomatosa in mother and daughter with serologic and histologic evidence.

Struma lymphomatosa in a mother and a daughter with serologic and histologic evidence is reported. Circulating antithyroid antibodies were also present in 2 of the 3 normal siblings of the affected daughter. The presence of struma lymphomatosa in the mother and daughter suggests that the defect which permits auto-immunization in this disease is genetic in origin. The histologic differences between struma lymphomatosa in children and adults are presented.
Air pollution and terrain aerodynamics: A review of fluid modeling studies at the EPA fluid modeling facility

Abstract Recent fluid modeling studies conducted at the EPA Fluid Modeling Facility of flow and diffusion in complex terrain are reviewed. Ratios of the maximum concentration on a hill surface to the maximum concentration in the absence of the hill are estimated. This ratio may be regarded as a terrain amplification factor and is a function of hill aspect ratio (two-versus three-dimensional), hill slope, atmospheric stability, etc. For upwind sources, terrain amplification factors are typically 1 to 2 for neutral flow over two-dimensional hills and 2 to 4 for three-dimensional hills. Terrain amplification factors as large as 10 or 15 were found for low sources placed downwind of two-dimensional hills of moderate to large slope. For strongly stable flow over three-dimensional hills, it is more useful to compare maximum surface concentrations with those at the centerline of the plume in the absence of the hill. These concentrations have been shown to be essentially equal.
MANAGEMENT OF PERINATAL TORSION: TODAY, TOMORROW OR NEVER?

Purpose: Management of perinatal testicular torsion is a highly controversial issue. Despite uncommon salvage of the affected gonad, exploration for ipsilateral orchiectomy and empiric contralateral orchiopexy have been recommended due to the unlikely but unfortunate possibility of asynchronous torsion. Observation with serial examination is the alternative. Risk of general anesthesia must be weighed against the risk of anorchia. We describe our collective experience with bilateral perinatal torsion, solidifying our recommendation for early exploration in all cases of perinatal torsion. Materials and Methods: All cases of perinatal torsion from 3 practices during a 3-year period were reviewed. All practices were at an academic center or in a major metropolitan area. Early exploration for contralateral orchiopexy was performed in all cases. Results: In 18 patients examination was consistent with unilateral perinatal torsion. Contralateral torsion was discovered at the time of exploration in 4 cases (22%). Despite orchiopexy of the better perfused gonad, atrophy was universal in these 4 cases. Findings potentially related to contralateral torsion were identified in 2 additional cases. No anesthetic or operative complications occurred. Conclusions: Bilateral asynchronous perinatal torsion is an uncommon but serious event. In our experience torsion of the contralateral gonad was not associated with signs or symptoms of acute torsion. Observation and serial examinations are then a challenging proposition. Due to the consistently poor outcome from bilateral asynchronous torsion, we continue to recommend early exploration and empiric contralateral orchiopexy for all cases of perinatal torsion. Parents must be counseled regarding the relative risks of exploration and anesthesia versus observation.
The significance of elderly migration to changes in elderly population concentration in the United States: 1960-1980.

Analysis of county level elderly and nonelderly [U.S.] net migration data revealed that overall migration was of less importance in explaining changes in elderly population concentration between 1970 and 1980 than it had been in the previous decade. However because of the spatial restructuring of both elderly and nonelderly migration the contribution of elderly migration relative to nonelderly migration increased from 1960 to 1980. Recognizable regional variations were apparent. Elderly migration not only remained significant in explaining changes in elderly population concentrations in traditional Sunbelt retirement states but also showed increased importance in newly emergent southern retirement states and in several northern states including a group in New England. (EXCERPT)
Interrelationships between the Retinal Neuroglia and Vasculature in Diabetes

For years, diabetic retinopathy has been defined based on vascular lesions, and neural abnormalities were not regarded as important. This review summarizes evidence that the neural retina has important effects on the retinal vasculature under normal conditions, and the interaction between the retinal neuroglial cells and vascular function is altered in diabetes. Importantly, new evidence raises a possibility that abnormalities within retinal neuroglial cells (notably photoreceptors) might actually be causing or initiating the vascular disease in diabetic retinopathy.
Caffeine Reduces Myocardial Blood Flow During Exercise

Caffeine consumption has been receiving increased interest from both the medical and lay press, especially given the increased amounts now available in energy products. Acute ingestion of caffeine usually increases cardiac work; however, caffeine impairs the expected proportional increase in myocardial blood flow to match this increased work of the heart, most notably during exercise. This appears to be mainly due to caffeine's effect on blocking adenosine-induced vasodilatation in the coronary arteries in normal healthy subjects. This review summarizes the available medical literature specifically relating to pure caffeine tablet ingestion and reduced exercise coronary blood flow, and suggests possible mechanisms. Further studies are needed to evaluate this effect for other common caffeine-delivery systems, including coffee, energy beverages, and energy gels, which are often used for exercise performance enhancement, especially in teenagers and young athletes.
Role of renin in the regulation of angiotensinogen levels in plasma.

SummaryThe role of renin in the regulation of its substrate was evaluated after administration of homologous renin. In normal rats, increases in plasma renin were associated with decreases in substrate. In nephrectomized rats, renin delayed but did not prevent the rise in substrate seen in nephrectomized controls, in spite of the high levels of plasma renin. An inverse relationship between renin and substrate levels was found after adrenalectomy and during pregnancy, but not after delivery. It is concluded that substrate consumption by renin plays a minor role in regulating substrate levels.
Systemic Chemotherapy for Uterine Carcinoma: Metastatic and Adjuvant

Endometrial carcinoma is the most common gynecologic malignancy in both the United States and the European Union. It often presents with vaginal bleeding at an early stage and can frequently be cured with surgery alone. Therefore, it is often perceived as a rare tumor by medical oncologists. However, an estimated 7,350 US women died of uterine cancer in 2006, a number in the same range as the 9,560 women estimated to have died of lymphoma. The median survival of women with advanced or recurrent disease on most recent clinical trials is only approximately 1 year. Metastatic endometrial carcinoma was formerly treated primarily with hormonal therapy, most commonly progestins. These agents produce response rates of up to 20% in patients not chosen for hormone receptor status and remain appropriate therapy for selected women. Over the past several decades, combination chemotherapy has come into widespread use in the treatment of metastatic endometrial cancer, and recent trials have begun to establish its use in the adjuvant setting.
Protons block the dark current of isolated retinal rods.

Abstract Membrane currents of isolated frog rods were recorded with the suction pipette technique and tested by perfusion techniques for their sensitivity to H+. The following facts have been established. (i) Increased [H+] suppresses the Na+ conductance of the outer segment rapidly and reversibly. (ii) H+ acts in the rod interior. (iii) The [H+] necessary to cause a 50% decrement in Na+ conductance is inversely related to the [Ca2+] over 5 orders of magnitude. (iv) The sensitivity to H+ and the sensitivity to light, as a function of [Ca2+], have the same slope. Thus, H+ act like light in effecting membrane current suppression but behave as if their effect is mediated through Ca2+. Based on these results and properties of rod disk membrane phosphodiesterase, we propose that protons produced in the light-activated hydrolysis of cGMP liberate Ca2+ from the disks by ion exchange.
Inhibition of whole plant respiration by elevated CO2 as modified by growth temperature

Plants of alfalfa (Medicago sativa) and orchard grass (Dactylus glomerata) were grown in controlled environment chambers at two CO2 concentrations (350 and 700 μmol mol-1) and 4 constant day/night growth temperatures of 15, 20, 25 and 30°C for 50–90 days to determine changes in growth and whole plant CO2 efflux (dark respiration). To facilitate comparisons with other studies, respiration data were expressed on the basis of leaf area, dry weight and protein. Growth at elevated CO2 increased total plant biomass at all temperatures relative to ambient CO2, but the relative enhancement declined (P≤0.05) as temperature increased. Whole plant respiration (Rd) at elevated CO2 declined at 15 and 20°C in D. glomerata on an area, weight or protein basis and in M. sativa on a weight or protein basis when compared to ambient CO2. Separation of Rd into respiration required for growth (Rg) and maintenance (Rm) showed a significant effect of elevated CO2 on both components. Rm was reduced in both species but only at lower temperatures (15°C in M. sativa and 15 and 20°C in D. glomerata). The effect on Rm could not be accounted for by protein content in either species. Rg was also reduced with elevated CO2; however no particular effect of temperature was observed, i. e. Rg was reduced at 20, 25 and 30°C in M. sativa and at 15 and 25°C in D. glomerata. For the two perennial species used in the present study, the data suggest that both Rg and Rm can be reduced by anticipated increases in atmospheric CO2; however, CO2 inhibition of total plant respiration may decline as a function of increasing temperature
Thermo-mechanical model with adaptive boundary conditions for friction stir welding of Al 6061

Abstract Thermo-mechanical simulation of friction stir welding can predict the transient temperature field, active stresses developed, forces in all the three dimensions and may be extended to determine the residual stress. The thermal stresses constitute a major portion of the total stress developed during the process. Boundary conditions in the thermal modeling of process play a vital role in the final temperature profile. The heating and cooling rates with the peak temperature attained by the workpiece determine the thermal stress. Also, predicting realistic peak temperature becomes important as the operating temperature at the interface of tool-workpiece is very close to the solidus temperature of the aluminum workpiece. The convection heat-transfer coefficients of the surfaces exposed to air can be theoretically determined using Newton's law of cooling. Contact conductance depends on the pressure at the interface and has a non-uniform variation. The actual pressure distribution along the interface is dependent on the thermal stress from local temperature and non-linear stress–strain state. Therefore, applying an adaptive contact conductance can make the model more robust for process parameter variations. A finite element thermo-mechanical model with mechanical tool loading was developed considering a uniform value for contact conductance and used for predicting the stress at the workpiece and backplate interface. This pressure distribution contours are used for defining the non-uniform adaptive contact conductance used in the thermal model for predicting the thermal history in the workpiece. The thermo-mechanical model was then used in predict stress development in friction stir welding.
Comparison of restriction endonucleases and sources of probes for their efficiency in detecting restriction fragment length polymorphisms in lettuce (Lactuca sativa L.)

As a first step in developing a detailed genetic map of lettuce (Lactuca sativa L.), 156 cDNA and 123 genomic DNA clones of lettuce were compared for their efficiency to detect restriction fragment length polymorphism (RFLP) between four lines of lettuce. Polymorphism was detected 2.5 times more frequently with cDNA probes than random genomic probes. Less polymorphism was detected with cDNA clones homologous to single copy than with cDNA clones homologous to multiple copy DNA sequences. A lower percentage of polymorphism was detected with genomic DNA clones homologous to repetitive sequences than with other types of probes. Digests with each of nine restriction endonucleases were compared; increased polymorphism was not correlated with the presence of a CpG dimer in the recognition sequence of the restriction endonuclease. Digests with enzymes recognizing four base pairs, however, displayed RFLPs less frequently. The six pairwise comparisons of the four lettuce lines showed different frequencies of polymorphism which only approximately corresponded to genetic distances obtained from previous isozyme analyses.
IEEE 802.11 Wireless LAN: can we use it for multimedia?

The IEEE P802.11 committee developed the 802.11 Wireless LAN standard to cover wireless networks for fixed, portable, and moving stations within a local area. This standard addresses the need for wireless connectivity to stations, equipment, or automatic machinery that requires rapid deployment and may be portable, handheld, or mounted on moving vehicles. It can function totally wireless or connected to a wired network. Most people familiar with the standard expect to use it in providing wireless networks for personal computers or stations connected to the global wired infrastructure through access points. Now that the 802.11 standard is finally here, it will energize the wireless LAN market and result in the proliferation of low cost wireless connectivity in the office and home. Study groups are working on higher rates at 2.4 GHz and at 5 GHz for future inclusion into the standard. These higher rates will make it even more practical to employ this standard for multimedia traffic.
Late quaternary spatial and temporal changes in clay- and silt-size mineral assemblages of fiord and shelf cores, western Baffin Bay, northwest North Atlantic

Clay- and silt-size mineral assemblages are described from eight piston cores from the fiords and shelf on the western margin of Baffin Bay, Arctic Canada. Radiocarbon dates indicate that all the cores extend back in time to the last local glacial/interglacial transition (i.e. 8–10 ka); four extend back to between 10 and 12 ka, and HU77-021-156, located on the Southeast Baffin Island shelf, includes the entire late Foxe glacial stage. Silt- and clay-size particles constitute ca 40 and 55%, respectively, by weight of the bulk sediment. The clay-size fraction is dominated by mica; feldspars and quartz are the main constituents of the silt fraction. The fiord sediments are mainly composed of local mineralogies, but on the shelf, and at times in the fiords, exotic mineral species occur. The most important of these are detrital carbonates, derived from erosion of the Paleozoic basins in Arctic Canada and/or northwest Greenland. Both calcite and dolomite occur; calcite is the major carbonate mineral in the “southern” cores, whereas dolomite is the most abundant in cores north of 66°N. Higher inputs of carbonate species occur during regional deglaciation, 7–10 ka, and during the last 5 ka (probably reflecting increased iceberg production from northwest Greenland). Thus variations in the precentages of the carbonate minerals indicate significant shifts in Late Quaternary glacial-sediment source areas and oceanographic regimes.
THE TOXICANT-WILDLIFE COMPLEX

ABSTRACT Familiar vertebrate wildlife comprise less than five per cent of the animal kingdom. A major proportion of the other thousands of non-insect species are aquatic and will be increasingly exposed to a wide variety of manmade and natural chemicals. Effective management of this toxicant-wildlife complex demands general and simple means for the prediction and estimation of effects and hazards. Direct, non-food exposure to toxicants is much more extensive than was expected and the bioconcentration of persistent compounds may be approximated by their lipid-water partition coefficients. Simple measures of distribution into soil organic matter and biota, environmental degradation, and toxicity then provide an estimate of relative hazard, extended and verified by both direct measurement and comparison of metabolites excreted by aquatic species and by predictive in vitro simulation of primary metabolism. These generalizations suggest that bioconcentration of stable substances usually will depend upon the fat content of individuals, may not be strongly affected by metabolism, will not inevitably lead to ‘biomagnification’, and will become increasingly predictive.
Adjunctive therapy with interstitial irradiation for prostate cancer

Abstract Thirty patients with clinically localized adenocarcinoma of the prostate underwent simultaneous staging pelvic lymphadenectomy and interstitial irradiation. Patients were followed for eighteen to forty-five months with regard to progression of disease and development of long-term complications. Upstaging to Stage D1 by virtue of discovering pelvic node involvement was noted in 16 patients (53.3 per cent). Subsequent disease progression (defined as development of bone or soft tissue metastasis) was seen in 9 of 16 upstaged patients with an average time to progression of 12.2 months. Three Stage D1 patients have died with an average time to death of 19.6 months. Only 1 patient whose lymphadenectomy was negative has experienced disease progression, and none has died. Adjuvant chemotherapy (cyclophosphamide and doxorubicin hydrochloride) was given to 9 upstaged patients, in only 3 did disease progress. In contrast, in 6 of 7 upstaged patients not receiving chemotherapy metastatic disease developed, with an average time to progression of 10.3 months. In an attempt to improve local tumor control achieved by interstitial irradiation alone, 18 patients received additional external beam radiation therapy to the prostate, in doses ranging from 2,000 to 40,000 rad. There were sixteen long-term complications in the 30 patients, 75 per cent of which were seen in patients receiving added external beam irradiation.