cssi/SciSciGPT-SciSciNet huggingface dataset:
The Transient Outward Current Ito Promotes Early Afterdepolarizations

The transient outward current (Ito) plays important roles in action potential (AP) morphology and arrhythmogenesis in cardiac diseases, such as ischemia and the Brugada syndrome. It is well accepted that early afterdepolarizations (EADs) occur under conditions of reduced repolarization reserve, which can result from either increased inward currents or reduced outward currents. Here we show the novel finding that Ito, an outward current, promotes EADs in rabbit ventricular myocytes, raising the question: how does an outward current promote EADs? To answer this question, we carried out experimental studies in isolated rabbit ventricular myocytes, theoretical analysis, and computer simulations. In myocyte experiments, exposure to 0.2-1 mM H2O2 at slow pacing rates induced EADs, which were eliminated by selectively blocking Ito with 2 mM 4-aminopyridine. Pre-treating myocytes with 4-aminopyridine prolonged AP, but likewise prevented H2O2-induced EADs. Voltage-clamp experiments showed that besides promoting late ICa,L and late INa, H2O2 also increased the maximum conductance, slowed the inactivation and accelerated the recovery from inactivation of Ito. When the cells were clamped with AP morphologies corresponding to the absence and presence of Ito, Ito significantly enhanced the Ca current, promoting its reactivation as the mechanism induced EADs. In a computer model of the rabbit ventricular AP, we also showed that the presence of Ito promoted EADs. The rate of Ito inactivation played a critical role: if too fast, no EADs occurred, and if too slow, AP duration became too short and no EADs occurred either. The underlying dynamical mechanisms were revealed by bifurcation theory of EADs previously developed by our group (Tran et al, Phys. Rev. Lett. 2009; 102:258103).
Sex-related differences in the antinociceptive effects of opioids: importance of rat genotype, nociceptive stimulus intensity, and efficacy at the µ opioid receptor

Rationale: Recent studies indicate that morphine is more potent as an antinociceptive agent in male than female rodents and monkeys. Objectives: To evaluate the influence of sex, nociceptive stimulus intensity and an opioid's relative efficacy on opioid-induced antinociception in rat strains (F344 and Lewis) that display differential sensitivity to morphine antinociception. Methods: Antinociceptive testing was conducted using a rat warm-water (50–56°C) tail-withdrawal procedure. Dose–response and time-course determinations were performed with various opioids. Results: Across the nociceptive stimulus intensities tested, the high-efficacy µ opioids morphine, etorphine, and levorphanol were equally effective in males and females, but on average 2.5-fold more potent in males. At moderate stimulus intensities, the low-efficacy µ opioid buprenorphine was approximately 0.4-fold more potent in males, and at higher stimulus intensities more potent and effective (greater maximal effect) in males. At low stimulus intensities, the low-efficacy µ opioid dezocine and the µ/κ opioid butorphanol were greater than 8.9-fold more potent in males, and at moderate stimulus intensities were more potent and effective in males. At a low stimulus intensity, the µ/κ opioid nalbuphine was more potent and effective in males. At stimulus intensities in which buprenorphine, dezocine, butorphanol, and nalbuphine produced maximal effects in males but not females, these opioids antagonized the effects of morphine in females. Genotype-related differences were noted as opioids were generally more potent in F344 than Lewis males, whereas no consistent differences were observed between F344 and Lewis females. Conclusions: That sex differences in the potency and effectiveness of opioids increased with decreases in the opioid's relative efficacy and with increases in the nociceptive stimulus intensity suggests that the relative efficacy of µ opioids as antinociceptive agents is greater in male than female rats.
The Lifelong Productivity of the Female Research hers in Terman's Genetic Studies of Genius Longitudinal Study

An analysis of information collected from historical archives reveals a wealth of data on 30 female researchers who worked in various capacities with Dr. Lewis Terman in conducting his classic longitudinal study. Genetic Studies of Genius (1925), on 1,528 gifted children in California. The published and unpublished papers, memoranda, and research field notes of these researchers, their respective correspondence With Terman and each other, and some contacts with a living member of the research teamn and family members were used for this analysis. Although the information is incomplete on some of the women, most of them appeared to have had satisfying personal lives in addition to productive professional careers. Not only did they each contribute greatly to the actual work of carrying out Terman's research conception, they also represent a continuum of life-long productivity. Personal responsibilities nay have had more to do with their subsequent levels of productivity than societal expectations or conventions.
Habitat and climate heterogeneity maintain beta‐diversity of birds among landscapes within ecoregions

Aim Habitat and climate heterogeneity may affect patterns of species diversity from the relatively local scale of communities to the broad biogeographical scale of continents. However, the effects of heterogeneity on species diversity have not been studied as widely at intermediate scales although differences among landscapes in local climate and habitat should maintain beta-diversity. Location Bailey ecoregions in the USA. Methods Using a geographically extensive dataset on bird distribution and abundance in 35 ecoregions, we tested for the effects of habitat and climate heterogeneity on beta-diversity at two discrete spatial scales: among sample points within landscapes, and among landscapes within ecoregions. Results Landscape-level beta-diversity typically accounted for 50% or more of gamma-diversity and was significantly and positively related to habitat heterogeneity (elevational range within an ecoregion) and climate heterogeneity (variation in potential evapotranspiration). Contrary to predictions, point-level beta-diversity was negatively related to habitat and climate heterogeneity, perhaps because heterogeneity constrains alpha-diversity at the landscape level. The geographical spatial separation of landscapes within an ecoregion did not significantly affect beta-diversity at either scale. Main conclusions Our results suggest that habitat selection and adaptation to local climate may be the primary processes structuring bird diversity among landscapes within ecoregions, and that dispersal limitation has a lesser role in influencing beta-diversity among landscapes.
Structural brain abnormalities and suicidal behavior in borderline personality disorder

Background Structural brain abnormalities have been demonstrated in subjects with BPD in prefrontal and fronto-limbic regions involved in the regulation of emotion and impulsive behavior, executive cognitive function and episodic memory. Impairment in these cognitive functions is associated with increased vulnerability to suicidal behavior. We compared BPD suicide attempters and non-attempters, high and low lethality attempters to healthy controls to identify neural circuits associated with suicidal behavior in BPD.
Three dimensional digital image processing using edge detectors

This paper provides an introduction to three dimensional image edge detection and its relationship to partial derivatives, convolutions and wavelets. We are especially addressing the notion of edge detection because it has far reaching applications in all areas of research to include medical research. A patient can be diagnosed as having an aneurysm by studying an angiogram. An angiogram is the visual view of the blood vessels whereby the edges are highlighted through the implementation of edge detectors. This process is completed through convolu- tion, wavelets and matrix techniques. Some illustrations included will be vertical, horizontal, Sobel and wavelet edge detectors.
Intensity-based oxygen imaging with a display screen and a color camera

Abstract Easily accessible optoelectronic devices were utilized to demonstrate a simple determination method of gaseous oxygen both quantitatively and qualitatively. A liquid crystal display (LCD) screen and a color charge-coupled device (CCD) camera were employed as a light source for fluorescence excitation and a photodetector for emission measurement, respectively. Meso-scale test platforms incorporating fluidic channels and oxygen sensor films were prepared. The ruthenium-complex sensor films were excited by blue light displayed from the LCD screen to emit fluorescence responding to gaseous oxygen. The color camera was used to map the distribution of red fluorescence emission from sensor films based on single-color intensity measurements. This combination of ubiquitous LCD and color camera enables a potential capability of uniform illumination and distribution recording over a large area with variable wavelength ranges. Possible niche application areas include multiple-analyte and high-throughput analysis over a large-area fluidic network.
Computer technology: State of the art

This article describes the nature of modern general-purpose computer systems. First it describes their hardware. The state of the semiconductor electronics art is discussed, with emphasis on the trend to microprocessors and large-scale memory chips. Then the various computer architectures in use are presented, showing the influence of electronic component evolution on the trend from processor-centered designs through storage-centered and multiprocessor designs to bus-oriented ones. After a brief discussion of input-output technology the article turns to system control programs, in many ways the most important aspect of computer systems as perceived by the user. Brief definitions and functional descriptions are provided of operating systems, program writing aids, database management systems, communications control programs, and utility programs.
Properties of Group VI B Elements Under Pressure. I. Melting Curves of S, Se, and Te

The melting curves of S, Se, and Te have been determined to 45 kbar by differential thermal-conductivity analysis in a tetrahedral anvil apparatus. The data for sulfur show that the melting point increases approximately linearly from 114\ifmmode^\circ\else\textdegree\fi{}C at atmospheric pressure to about 700\ifmmode^\circ\else\textdegree\fi{}C at 45 kbar. Rhombic sulfur melted under pressure is found to crystallize upon solidification in the amorphous plastic form, which can be retained metastably at atmospheric pressure. The selenium melting curve is slightly concave toward the pressure axis and rises from 220\ifmmode^\circ\else\textdegree\fi{}C at atmospheric pressure to 650\ifmmode^\circ\else\textdegree\fi{}C at 40 kbar. A maximum in the melting curve of tellurium is observed at about 10 kbar and 480\ifmmode^\circ\else\textdegree\fi{}C. These experimental results are discussed in relation to the current ideas on the general nature of melting curves. The maximum in the melting curve of tellurium is explained in terms of coordination in the liquid state and the existence of a liquid-state structural change of a statistical nature, which appears to divide the liquid into a metallic and a semiconducting phase. It is predicted that selenium, and, perhaps, sulfur also have maxima in their melting curves. The normalized change in resistivity upon melting ($\frac{\ensuremath{\Delta}\ensuremath{\rho}}{\ensuremath{\rho}}$) is correlated with the atmospheric-pressure melting-curve slopes ${m}_{0}$ for a number of elements. A plot of ${m}_{0}$ versus ($\frac{\ensuremath{\Delta}\ensuremath{\rho}}{\ensuremath{\rho}}$) shows that the data for the elements considered, except the alkali metals and the Group VI B elements, very roughly define a linear relationship. The sign of ${m}_{0}$ and ($\frac{\ensuremath{\Delta}\ensuremath{\rho}}{\ensuremath{\rho}}$) is the same for all elements considered except S, Se, and Te. A general relation between the change upon melting in the short-range order of the atomic distribution and the sign of ${m}_{0}$ is also discussed. The semimetals, for which ${m}_{0}l0$, undergo striking changes in short-range order, whereas the metals, for which ${m}_{0}g0$, exhibit a continuity of short-range order.
Assessing Risk for Cardiovascular Disease in Patients With Human Immunodeficiency Virus: Why it Matters

Physicians who regularly see patients with human immunodeficiency virus (HIV) are commonly asked the prognosis of someone with HIV infection today. Although the estimates vary depending on the CD4 cell count and age at diagnosis, studies suggest that survival for most people with HIV is currently measured in decades, not years.1,2 For example, in one study from Denmark the estimated median survival from age 25 in HIV-infected patients without hepatitis C was 39 years. Indeed, these per-person gains in survival accrued from antiretroviral therapy (ART) are of a magnitude unmatched in treatment of other diseases.3 Article see p 651 Effective ART has therefore led to a marked shift in the age distribution among people with HIV in the United States, and it is estimated that by 2015 more than half will be over 50 years of age.4 Given this improved survival, it is not surprising that people with HIV in whom therapy is successful are increasingly at risk for diseases of aging, in particular cardiovascular, renal, and “non-AIDS” neoplastic diseases. Furthermore, these complications seem to be occurring at higher rates than in age-matched control individuals, likely accounting for the fact that survival of HIV patients still does not match that in the uninfected population,1 even though viral replication can be controlled in the vast majority of patients in care.5 In addition, clinical observations from clinicians and patients, some of which have prominently appeared in the lay press,6,7 cite a process of accelerated aging and debility among those with HIV despite effective treatment. With cardiovascular disease (CVD) in …
A Qualitative Study on the Socialization of Beginning Physical Education Teacher Educators

Abstract Few studies have focused on how university faculty learn and understand expectations of their professional role. The purpose of this study was to describe the experiences of five female physical education teacher educators in their first positions as assistant professors in research oriented universities. Data were collected, using primarily qualitative methods—weekly journals and in-depth interviews. Quantitative data were gathered to compare organizational factors such as salary, load allocation, equipment, and travel funds. Data yielded five main categories concerning how and what participants learned, about their faculty roles. These categories included participants' perceptions of (a) organizational structure and job facilitation, (b) work tasks, (c) support systems, (d) evaluation and feedback, and (e) participants' psychological states. All participants reported experiencing role ambiguity and stress. Clear criteria for job performance, collegial support and mentoring, and regular evaluati...
A Quenching Furnace for High‐Temperature Studies of Small Specimens

A high-temperature, quenching furnace for study of small specimens is described. A heavy tungsten wire coil is used as a heat source. The furnace can be operated in a vacuum or in reducing or neutral atmospheres. This quenching furnace has been applied successfully to temperatures as high as 2300°C. in phase equilibrium studies of the systems ZrO2-TiO2 and ZrO2-TiO2-SiO2.
Food insufficiency exists in the United States: results from the third National Health and Nutrition Examination Survey (NHANES III).

OBJECTIVES: The purpose of this study was to estimate the prevalence of food insufficiency in the United States and to examine sociodemographic characteristics related to food insufficiency. METHODS: Data were analyzed from the third National Health and Nutrition Examination Survey, a cross-sectional representative sample of the civilian noninstitutionalized population living in households. Individuals were classified as "food insufficient" if a family respondent reported that the family sometimes or often did not get enough food to eat. RESULTS: From 1988 through 1994, the overall prevalence of food insufficiency was 4.1% and was primarily related to poverty status. In the low-income population, food insufficiency was positively associated with being Mexican American, being under the age of 60, having a family head who had not completed high school, participating in the Food Stamp Program, and not having health insurance. It was not related to family type or employment status of the family head. Over hal...
Pathogenesis of hepatitis B and C-induced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is estimated to have an annual worldwide incidence of 0.25 to 1.2 million new cases per year. Both the prevalence and incidence of HCC vary markedly as a function of geography and the local prevalence of chronic viral hepatitis. Both chronic hepatitis B and chronic hepatitis C are recognized as risk factors for HCC. The prevalence of cirrhosis in individuals with HCC and chronic hepatitis B or C is reported to be 80.9% and 75.8%, respectively. HCC occurs at a lower rate in chronic viral hepatitis in the absence of cirrhosis. Moreover, hepatitis C virus (HCV) rather than hepatitis B virus (HBV) is associated with the majority of non-cirrhotic cases of HCC. It is probable that the ongoing process of hepatocyte necrosis and liver cell renewal coupled with inflammation, which is characteristic of chronic viral hepatitis, causes not only nodular regeneration and cirrhosis but also progressive genomic errors in hepatocytes as well as unregulated growth and repair mechanisms leading to hepatocyte dysplasia and, in some cases, hepatic carcinoma. Current concepts concerning virus-induced HCC are reported and discussed in the following review.
Photon echo and valence-band mixing in semiconductor quantum wells.

The coherent optical response of semiconductor quantum wells is studied theoretically using the multiband semiconductor Bloch equations which include coupling of the heavy- and light-hole bands as well as many-body Coulomb effects. For the case of a two-pulse excitation scheme it is shown how the different rotational symmetries of heavy- and light-hole bands induce a strong polarization dependence of the signal in the photon echo direction. The selection rules are based on the Kane-Luttinger theory while the transition amplitudes are obtained by numerically solving the multiband semiconductor Bloch equations. In addition, the influence of valence-band mixing effects on the optical Stark effect is demonstrated.
Two Potent Nuclear Localization Signals in the Gut-enriched Krüppel-like Factor Define a Subfamily of Closely Related Krüppel Proteins

The gut-enriched Kruppel-like factor (GKLF) is a newly identified transcription factor that contains three C2H2 Kruppel-type zinc fingers. Previous immunocytochemical studies indicate that GKLF is exclusively localized to the nucleus. To identify the nuclear localization signal (NLS) within GKLF, cDNA constructs with various deletions in the coding region of GKLF were generated and analyzed by indirect immunofluorescence in transfected COS-1 cells. In addition, constructs fusing regions representing putative NLSs of GKLF to green fluorescent protein (GFP) were generated and examined by fluorescence microscopy in similarly transfected cells. The results indicate that GKLF contains two potent, independent NLSs: one within the zinc fingers and the other in a cluster of basic amino acids (called 5′ basic region) immediately preceding the first zinc finger. In comparison, putative NLSs within the zinc fingers and the 5′ basic region of a related Kruppel protein, zif268/Egr-1, are relatively less efficient in their ability to translocate GFP into the nucleus. A search in the protein sequence data base revealed that despite the existence of numerous Kruppel proteins, only two, the lung Kruppel-like factor (LKLF) and the erythroid Kruppel-like factor (EKLF), exhibit similar NLSs to those of GKLF. These findings indicate that GKLF, LKLF, and EKLF are members of a subfamily of closely related Kruppel proteins.
Computer technology in eastern European countries and the former Soviet Union: An interpretative bibliography

Eastern Europe and the Commonwealth of Independent States are going through deep and dramatic changes and are entering a new era. The development of high‐technology industries is considered crucial to help revitalize the economies of Bulgaria, Czech Republic, Slovakia, the eastern provinces of Germany (former German Democratic Republic), Hungary, Poland, Romania, and the old Soviet Union. Moreover, the current status, operation, and progress of the information processing industry represent the most fascinating areas of old East Bloc industrialization. It is widely known that the majority of industries in these countries are obsolete in comparison with the Western countries. Computer and communications technologies comprise this branch of industry where the technological gap between East and West is the widest. Catching up with western countries would take eastern countries ten years for software and supercomputers, eight years for mainframes, six years for microprocessors, and five years for minicomputers. Western countries consider this necessity to catch up as one of the main obstacles to future European integration.
Lower limits for parallel impurity fluxes in the PLT edge plasma

Lower limits for time-resolved anti B-parallel impurity fluxes to solid collectors immersed in the PLT edge plasma have been determined as a function of minor radius. Using geometric shadowing of the probe surface, features attributed to finite ion gyroradii have been observed. Also, for r less than 48 cm, heat pulses of less than 2 ms duration and greater than 2.5 x 10/sup 3/ W/cm/sup 2/ intensity were found to occur at the termination of many discharges.
Vespa Process for Analysis of Seismic Signals

This article describes applications of the Vespa process to study P waves from seismic events and also to extract seismic signals arriving at the same time but from different approach angles.
Rotating crystal cube as a variable shutter for use with synchrotron radiation

A beam chopper together with the temporal structure of x-rays emitted by a synchrotrons storage ring can be utilized to generate x-ray bursts of variable length and time separation. A Si cube, cut for diffraction from the (220) planes, was mounted to a low-speed motor to produce a beam chopper based upon the Darwin width of the crystal. An x-ray pulse, consisting of an envelope of individual pulses characterizing the loading pattern of the storage ring, was transmitted. The width of the transmitted pulse and the time between pulses was varied by varying the rotation frequency of the Si cube. Pulses as short as {approx} 75 ps or as long as {approx} 4 {micro}s were transmitted with pulse separation spanning from 4 ms to 167 ms.
A dominant-negative form of p63 is required for epidermal proliferation in zebrafish.

Abstract Epidermal stem cells play a critical role in producing the multilayered vertebrate skin. Products of the p63 gene not only mark the epidermal stem cells, but also are absolutely required for the formation of mammalian epidermis. We find that early zebrafish embryos express a dominant-negative form of p63 (ΔNp63), which accumulates in the nucleus just as epidermal growth begins. Using antisense morpholino oligonucleotides, we show that ΔNp63 is needed for epidermal growth and limb development and is specifically required for the proliferation of epidermal cells by inhibiting p53 activity. While the structure of fish epidermis is very different from that of higher vertebrates, our study shows that ΔNp63 has essential and ancient role in the development of skin.
Elevated concentrations of leukotriene D4 in pulmonary edema fluid of patients with the adult respiratory distress syndrome

The possible contribution of metabolites of arachidonic acid to the increased permeability of the alveolar-capillary barrier in the adult respiratory distress syndrome was examined by quantifying the pulmonary edema fluid concentrations of lipoxygenase and cyclooxygenase products. The concentration of leukotriene D4 in pulmonary edema fluid of 10 patients with the adult respiratory distress syndrome (18.5±6.8 pmol/ml; mean±SD), assessed by specific radioimmunoassay after isolation of the mediator, was significantly higher (P<0.001) than that of five patients with cardiogenic pulmonary edema (4.4±1.1 pmol/ml). The concentrations of leukotrienes B4 and C4, prostaglandin E2, and thromboxane B2 in edema fluid were not significantly different in the adult respiratory distress syndrome patients than in the other subjects with pulmonary edema. The edema fluid concentration of leukotriene D4 correlated with the ratio of edema fluid to plasma concentrations of albumin (r=0.64). Leukotriene D4 thus may contribute to the permeability defect which allows an accumulation of proteinrich alveolar fluid in the adult respiratory distress syndrome.
Cosmic-ray diffusion near the Bohm limit in the Cassiopeia A supernova remnant

The acceleration of cosmic rays in our Galaxy by means of diffusive shock (Fermi) acceleration is believed to occur primarily in supernova remnants (SNRs). Despite considerable theoretical work, the precise details are still unknown, in part because of the difficulty in directly observing nucleons that are accelerated to TeV energies in—and affect the structure of—SNR shocks. However, for the past ten years, X-ray observatories such as ASCA (Advanced Satellite for Cosmology and Astrophysics) and, more recently, Chandra, XMM-Newton and Suzaku, have made it possible to image the keV-scale synchrotron emission produced by cosmic-ray electrons accelerated in SNR shocks. Here, we describe a spatially resolved spectroscopic analysis of Chandra observations of the Galactic SNR Cassiopeia A to map the cutoff frequencies of electrons accelerated in the forward shock. We set upper limits on the diffusion coefficient and find locations where particles seem to be accelerated nearly as fast as theoretically possible (the Bohm limit).
GASing up iron delivery via STAT5

Ramping up and maintaining a high rate of iron delivery to support heme biosynthesis is both unique and fundamental to erythroid maturation. In this issue, Zhu and colleagues reveal a previously unappreciated role of the cytokine-activated transcription factor STAT5A/B as a regulator of iron
Rationality of appeals used in the promotion of psychotropic drugs. A comparison of male and female models.

Abstract Content analysis was performed on 329 different advertisements for psychotropic drugs which appeared in medical journals in 1974. Ads were classified by the nature of the sales appeal and the sex of the patient portrayed. Male patients were associated with the use of rational (as defined by the study) appeals significantly more often than were female patients. The illustration portions of the ads were associated with non-rational appeals in the majority of the ads, while the headline and text were more often associated with rational appeals. The influence of these advertising practices on prescribing has not been demonstrated, but the implications are important enough to warrant further study.
Meteorological conditions accompanying mirages in the Salt Lake Desert

Abstract Meteorological conditions commonly or invariably accompanying mirages in the Salt Lake Desert are here described, and the descriptions illustrated with photographs and instrumental records, where such are available and pertinent. Extended observation indicates that mirages are a standard and predictable phenomenon in the Salt Lake Desert. Less extended field studies show that similar meteorological conditions accompany mirages in all other American deserts.
Architecture of multilayer nanocomposite coatings with super-hard diamond-like carbon layers for wear protection at high contact loads

Abstract Super-hard and low-friction diamond-like carbon (DLC) coatings deposited at low temperatures are currently of great interest for wear protection and friction reduction. However, their high hardness (50–80 GPa), intrinsic stresses, and poor adhesion limit their use to applications where contact pressures are below I GPa and the coating thickness is below 0.5 μm to prevent cracking and delamination. These negative effects are especially pronounced when the coatings are applied to relatively soft substrates, such as steels. The limitations were removed by a multilayer design, where metal and ceramic layers were used to increase the load support capability, improve the adhesion strength, and increase the thickness of DLC layers. Existing approaches to the design of tough multilayer coatings were considered critically and a coating architecture was suggested using the following concepts: (i) formation of a load support and adhesion promoting underlayer with mechanical characteristics varied gradually from the substrate to the DLC layer; (ii) separation of hard DLC layers with interlayers of softer material to reduce stresses and brake cracks; (iii) use of crystalline interlayers with thickness permitting operation of dislocation sources for stress relaxation and deflection of cross-sectional cracks. The development of these concepts is discussed sequentially from bilayer ceramic/DLC coatings to functionally gradient metal/carbide/DLC coatings, and finally to nanocomposite coatings consisting of stacks of Ti/DLC, TiC/DLC, and CN/DLC layers with individual thickness within 10–60 nm deposited onto a gradient TiTiC-DLC underlayer. The coatings were deposited onto stainless steel substrates by a hybrid of magnetron sputtering and pulsed laser deposition. They had a 1–2 μm total thickness of super-hard (60–70 GPa) DLC layers and resisted delamination to 50–80 N loads in scratch adhesion tests. In ball-on-disk sliding tests, these coatings supported Hertzian contact pressures above 2 GPa and had friction coefficients around 0.1. Their wear lives exceed 10 6 cycles under initial contact pressures of 1.4 GPa. The conceptual architecture of multilayer nanocomposite coatings presented extends the range of wear resistant applications for super-hard DLC materials.
Organizational capital and the choice between specialization and diversification

This paper specifies a model in which the preservation of organizational capital is the principal factor motivating corporate diversification decisions. Alternative hypotheses of the determinants of diversification are then subjected to empirical test with data for 96 US industrial firms in the 1967–71 period. Consistent with the model, variables associated with unfavorable expectations on the marginal returns to investment in existing activities proved dominant in explaining ‘desired’ increases in diversification. Alternative explanations, namely, the role of managerial attributes, of absolute advantages of some firms, and of opportunities created by research and development, had more modest explanatory power.
The K-Quotient

Abstract The Rayleigh Quotient and a recently proposed Timoshenko Quotient [1] are upper bounds to the fundamental eigenvalue of a discrete dynamic system. The closeness of these upper bounds to the fundamental eigenvalue depends on the closeness of the trial vectors to the eigenmode used in the calculation. In the present paper, a new quotient is presented. This quotient does not require the closeness of the trial vector to the eigenmode and its accuracy is improvable by raising the numerical value of the parameter p.
Recent Developments in Nuclear Medicine Instrumentation

Nuclear Medicine instrumentation, as is the case for most sophisticated technologies, is constantly being improved through the introduction of new devices as well as through refinements in devices that are available from several manufacturers. The purpose of this text is to describe the recent developments that have led to improvements in the performance of instruments currently being used for routine diagnostic studies and to also describe some of the new devices that are becoming available.
Transcriptional Regulation of the Cyclooxygenase-2 Gene Changes from Protein Kinase (PK) A- to PKC-Dependence after Luteinization of Granulosa Cells

Abstract This study was designed to elucidate the molecular mechanism(s) mediating cyclooxygenase-2 (Cox-2) regulation during differentiation of the granulosa cell. The 5′ flanking sequence of the Cox-2 gene was linked to a vector with a luciferase reporter gene, and this vector was transfected into freshly isolated bovine granulosa cells or granulosa cells after culture with or without forskolin to induce luteinization in vitro. The Cox-2 promoter was inducible by 8-bromo cAMP but not by phorbol esters in fresh granulosa cells, and maximal expression by cAMP was delayed until 48 h after treatment. In contrast, after luteinization of granulosa cells by 8-day treatment with forskolin, the Cox-2 promoter was immediately inducible by phorbol esters but not by cAMP. In granulosa cells cultured for 8 days without forskolin, the Cox-2 promoter continued to be inducible only by cAMP and not by phorbol esters. Unexpectedly, no delay was observed in the induction of Cox-2 by cAMP in granulosa cells that were cultu...
Cholesterol Interacts with Transmembrane α-Helices M1, M3, and M4 of the Torpedo Nicotinic Acetylcholine Receptor: Photolabeling Studies Using [3H]Azicholesterol†

The photoactivatable sterol probe (3R- 3 H)6-Azi-5R-cholestan-3‚-ol (( 3 H)Azicholesterol) was used to identify domains in the Torpedo californicanicotinic acetylcholine receptor (nAChR) that interact with cholesterol. ( 3 H)Azicholesterol partitioned into nAChR-enriched membranes very efficiently (>98%), photoincorporated into nAChR subunits on an equal molar basis, and neither the pattern nor the extent of labeling was affected by the presence of the agonist carbamylcholine, consistent with photoincorporation at the nAChR lipid-protein interface. Sites of ( 3 H)Azicholesterol incorporation in each nAChR subunit were initially mapped by Staphylococcus aureusV8 protease digestion to two relatively large homologous fragments that contain either the transmembrane segments M1-M2-M3 (e.g., RV8-20) or M4 (e.g., RV8-10). The distribution of ( 3 H)Azicholesterol labeling between these two fragments (e.g., RV8-20, 29%; RV8-10, 71%), suggests that the M4 segment has the greatest interaction with membrane cholesterol. Photolabeled amino acid residues in each M4 segment were identified by Edman degradation of isolated tryptic fragments and generally correspond to acidic residues located at either end of each transmembrane helix (e.g., RAsp-407). ( 3 H)Azicholesterol labeling was also mapped to peptides that contain either the M3 or M1 segment of each nAChR subunit. These results establish that cholesterol likely interacts with the M4, M3, and M1 segments of each subunit, and therefore, the cholesterol binding domain fully overlaps the lipid-protein interface of the nAChR.
Studies with Corn-Soya Laying Diets: 4. Environmental Temperature—A Factor Affecting Performance of Pullets Fed Diets Suboptimal in Protein

Abstract IN OUR experience, egg production trends of pullets fed diets suboptimal in protein have varied with season when the birds were confined to a building where only limited control over prevailing temperatures was possible. No such effect was observed when the diets contained a plethora of protein Conceivably, with a plethora of protein in the diet, a reduction in the voluntary consumption of feed does not lower the absolute protein intake to a point where this nutrient becomes critical, whereas with diets containing marginal or suboptimal levels of protein, protein intake may become the first limiting factor. The report of Mills (1944) suggested this hypothesis since he has shown that rats not only gained more at a given suboptimal dietary protein level, but also that growth was maximized at a lower protein level in a 68°F. chamber, than in one maintained at 90°F. Growth at these two temperatures was comparable…
Ion implantation effects on GaAs MESFETs

The effects of ion-implantation on the uniformity and the ultimately achievable performance of GaAs MESFETs are calculated. The results of an extensive study of the profiles of Si, Se, and Be ions implanted into GaAs are incorporated into a combined process and device model for GaAs MESFET technology. Taken into account are the scaling of transconductances with implantation energy, effects of implant profiles and impurities on low-gate-bias transconductances, dopant diffusion during annealing, effects of encapsulant thickness and etch depth on threshold-voltage uniformity, and effects of recoil atoms on threshold voltages for implants through Si/sub 3/N/sub 4/ and SiO/sub 2/ caps. >
Acquisition of Pig Latin: a case study.

A boy's acquisition of Pig Latin was monitored throughout the year preceding first grade. Abilities underlying this game include the identification of words, deletion of the first syllabic onset (i.e. prevocalic consonants) of each word, blending of this onset and the suffix [ei] onto the word's end, and short-term memory for speech units. Performance improved over time as the underlying abilities developed. Meanwhile, various informative errors were made. Throughout most of the study, onsets that were correctly removed from a word's beginning were often added to its end incorrectly; unstressed function words were repeated intact and not transformed; and the first syllabic onset was overlooked when the syllable was unstressed. Because speech games like this one depend upon basic language skills, they can clarify aspects of ordinary language development.
Residues in a Highly Conserved Claudin-1 Motif Are Required for Hepatitis C Virus Entry and Mediate the Formation of Cell-Cell Contacts

Claudin-1, a component of tight junctions between liver hepatocytes, is a hepatitis C virus (HCV) late-stage entry cofactor. To investigate the structural and functional roles of various claudin-1 domains in HCV entry, we applied a mutagenesis strategy. Putative functional intracellular claudin-1 domains were not important. However, we identified seven novel residues in the first extracellular loop that are critical for entry of HCV isolates drawn from six different subtypes. Most of the critical residues belong to the highly conserved claudin motif W 30 -GLW 51 -C 54 -C 64 . Alanine substitutions of these residues did not impair claudin-1 cell surface expression or lateral protein interactions within the plasma membrane, including claudin-1-claudin-1 and claudin-1-CD81 interactions. However, these mutants no longer localized to cell-cell contacts. Based on our observations, we propose that cell-cell contacts formed by claudin-1 may generate specialized membrane domains that are amenable to HCV entry.
Variational path profiling

Current profiling techniques are good at identifying where time is being spent during program execution. These techniques are not as good at pinpointing exactly where in the execution there are definite opportunities a programmer can exploit with optimization. In this paper we present a new type of profiling analysis called variational path profiling (VPP). VPP pinpoints exactly where in the program there are potentially significant optimization opportunities for speedup. VPP finds the acyclic control flow paths that vary the most in execution time (the time it takes to execute each occurrence of the path). This is calculated by sampling the time it takes to execute frequent paths using hardware performance counters. The motivation for concentrating on a path with a high net variation in its execution time is that it can potentially be optimized so that most or all executions of that path have the minimal execution time seen during profiling. We present a profiling and analysis approach to find these variational paths, so that they can be communicated back to a programmer to guide optimization. Our results show that this variation accounts for a significant fraction of overall program execution time and a small number of paths account for a large fraction of this variation. By applying straight forward prefetching optimizations to these variational paths we see 8.5% speedups on average.
Use of the Trendelenburg Position as the Resuscitation Position: To T or Not to T?

OBJECTIVE To review the literature on use of the Trendelenburg position as a position for resuscitation of patients who are hypotensive. METHODS PubMed online, cited bibliographies, critical care textbooks, and Advanced Cardiac Life Support guidelines were searched for information on the position used for resuscitation. Because of the heterogeneity of the data, only pertinent articles and chapters were summarized. RESULTS Eight peer-reviewed publications on the position used for resuscitation were found. Pertinent information from 2 critical care textbooks and from the Advanced Cardiac Life Support guidelines was included in the review. Literature on the position was scarce, lacked strength, and seemed to be guided by "expert opinion." CONCLUSION The general "slant" of the available data seems to indicate that the Trendelenburg position is probably not a good position for resuscitation of patients who are hypotensive. Further clinical studies are needed to determine the optimal position for resuscitation.
Use of Cefoperazone in the Empiric Treatment of Serious Skin Infections

This report summarizes the results of a six-center clinical trial of cefoperazone as empiric therapy for hospitalized patients with serious infections of the skin and skin structures. Cefoperazone was administered in doses of 2-4 g once every 12 hr by iv infusion over 15-30 min or im injection. Results of therapy were evaluated for 39 of the 46 patients enrolled in the study. Of these 39 patients, 30 had a satisfactory clinical response to cefoperazone therapy, six had a partly satisfactory response, and three had an unsatisfactory response. A total of 78 pathogens were isolated from infected sites of the 39 patients, and MICs were determined for 62 of these pathogens. Of the 78 isolated pathogens, 63 (including five of eight isolates of Pseudomonas aeruginosa) were eradicated by cefoperazone. It is concluded that cefoperazone is a suitable antibiotic for empiric therapy for infections of the skin and skin structures of hospitalized patients.
Urban redevelopment and grassroots action in Chicago and Sheffield: themes, variations and uncertain legacies

In the Uptown area of Chicago and Sheffield, England’s Sharrow neighborhood, redevelopment initiatives in the late 1960s and early 1970s produced a significant degree of community conflict. Throughout the 1970s and 1980s a variety of grassroots movements appeared in each community. The legacy of redevelopment-derived conflict and community-based organizing in the two communities suggests that there is more variation in neighborhood grassroots politics — even in communities with comparable public policy and organizing histories — than prevailing explanations of neighborhood mobilization tend to acknowledge. However, with the 1990s a convergence in the Uptown and Sharrow experiences has appeared: the narrowing of their grassroots organizations’ political agendas, which can be attributed to national shifts in political discourse and public policy. Dans le quartier de Uptown a Chicago et le quartier de Sharrow a Sheffield en Angleterre, les initiatives de redeveloppement a la fin des annees soixante et le debut des annees soixante-dix ont cause un degre significatif de conflit dans la communaute. Durant les annees soixante-dix et quatre-vingt divers mouvements populaires sont apparus dans ces communautes. Dans les deux communautes, le resultat des conflits dus au redeveloppement et de l'organisation basee dans la communaute suggere qu'il y a plus de variation dans les politiques populaires des quartiers — meme dans les communautes qui ont des politiques publiques et un passe d'organisation similaires — que les explications dominantes de la mobilisation de quartier tendent a reconna^tre. Cependant, dans les annees quatre-vingt-dix, une convergence entre les experiences de Uptown et Sharrow est apparue: le retrecissement des programmes politiques de leurs organisations populaires qui peut etre attribue aux changements nationaux du discours politique et de la politique publique.
A Varactor-Based Reconfigurable Filtenna

This letter details a new reconfiguration technique for implementing frequency-tunable bandpass filters. This is achieved by changing the filter total capacitance via an integrated varactor within its structure. The reconfigurable bandpass filter is then incorporated within the feeding line of a printed antenna to form one structure. This combination allows the tuning of the antenna operating frequency without incorporating active components and biasing lines on the antenna radiating surface. The integrated antenna-filter combination, with filtering ability while preserving the radiation performance, is referred to as a “filtering antenna” or a filtenna. A prototype for the reconfigurable filter and the reconfigurable filtenna are fabricated and tested. A good agreement is found between the simulated and the measured data.
A framework for group integrity management in multimedia multicasting

Multicast research has so far been focused on routing and network-level group management. Conditions on the composition of multicast groups have however been kept simple, with little efforts to specify requirements in terms of membership, member roles and group organization. Integrity conditions on multicast groups have been largely neglected despite the fact that it is often desirable to express who should be admissible as a member, with what role and privileges, what relation a group should have to other groups, etc. Furthermore, the traditional multicasting model has been flat, with no finer granularity than a group, and without inter-group relationships. In this paper, we address both issues that we see as shortcomings of current models. We introduce a framework that allows us to sub-divide multicast groups into subgroups, e.g. for low and high quality versions of a media stream, and, on the other hand, to form and manage meta groups from groups, thus integrating "multi" media groups. On all three levels, our framework provides for specification of various integrity conditions as part of a comprehensive policy framework, including integrity on state and state transition as well as action and transition policies for group management.
TES spectroscopic identification of a region of persistent water ice clouds on the flanks of Arsia Mons Volcano, Mars

[1] As part of a search for small-scale spectrally anomalous regions within the Mars Global Surveyor Thermal Emission Spectrometer (MGS/TES) data set, we have identified a region ∼100 km in diameter on the southwest flanks of the volcano Arsia Mons that exhibits remarkable and persistent water ice cloud cover. High-opacity clouds (by Martian standards) occur in this region in all of the 400 TES spectra covering this area, regardless of season, as well as in all of the MGS Wide-Angle camera images of this same region. We have also found evidence for similar persistent cloudiness at other local solar times of day in this region based on Hubble Space Telescope UV imaging. Modeling of the TES spectra identifies the clouds as water ice and reveals average IR cloud optical depths near 0.5 and typical cloud particle sizes of ∼3 μm. The presence of persistent cloudiness in this area, even during the relatively warm and cloud-free season near perihelion, may indicate unique local circulation processes, perhaps related to orographic effects or the interaction between the global circulation and the Tharsis region in general. Our analysis also demonstrates that through careful modeling it is possible to extend the search for unique spectral features in the TES data far into the wings of the strong 15-μm CO2 band.