cssi/SciSciGPT-SciSciNet huggingface dataset:
A performance evaluation of the cray x1 for scientific applications

The last decade has witnessed a rapid proliferation of superscalar cache-based microprocessors to build high-end capability and capacity computers primarily because of their generality, scalability, and cost effectiveness. However, the recent development of massively parallel vector systems is having a significant effect on the supercomputing landscape. In this paper, we compare the performance of the recently-released Cray X1 vector system with that of the cacheless NEC SX-6 vector machine, and the superscalar cache-based IBM Power3 and Power4 architectures for scientific applications. Overall results demonstrate that the X1 is quite promising, but performance improvements are expected as the hardware, systems software, and numerical libraries mature. Code reengineering to effectively utilize the complex architecture may also lead to significant efficiency enhancements.
Functional aortic stiffness: role of CD4(+) T lymphocytes

The immune system is suggested to be essential in vascular remodeling and stiffening. To study the dependence upon lymphocytes in vascular stiffening, we compared an angiotensin II-model of vascular stiffening in normal C57BL/6J mice with lymphocyte-deficient RAG 1(-/-) mice and additionally characterized the component of vascular stiffness due to vasoconstriction vs. vascular remodeling. Chronic angiotensin II increased aortic pulse wave velocity, effective wall stiffness, and effective Young's modulus in C57BL/6J mice by three-fold but caused no change in the RAG 1(-/-) mice. These functional measurements were supported by aortic morphometric analysis. Adoptive transfer of CD4(+) T helper lymphocytes restored the angiotensin II-mediated aortic stiffening in the RAG 1(-/-) mice. In order to account for the hydraulic vs. material effects of angiotensin II on pulse wave velocity, subcutaneous osmotic pumps were removed after 21 days of angiotensin II-infusion in the WT mice to achieve normotensive values. The pulse wave velocity (PWV) decreased from three- to two-fold above baseline values up to 7 days following pump removal. This study supports the pivotal role of the CD4(+) T-lymphocytes in angiotensin II-mediated vascular stiffening and that angiotensin II-mediated aortic stiffening is due to the additive effect of active vascular smooth muscle vasoconstriction and vascular remodeling.
Genetic algorithms for control of power converters

This paper evaluates genetic algorithms (GAs) as a new nonlinear technique for the control of power converters. Genetic algorithms are a class of parallel processing learning techniques. They are used to optimize power converter control laws relative to a performance index. An example using a full-bridge topology verifies the usefulness of this technique. >
Three Examples of Computer — Intensive Statistical Inference

We discuss three recent data analyses which illustrate making statistical inferences (finding significance levels, confidence intervals, and standard errors) with the critical assistance of a computer. The first example concerns a permutation test for a linear model situation with several covariates. We provide a computer-based compromise between complete randomization and optimum design, partially answering the question “how much randomization is enough?”
Introduction to a Compendium on Sudden Cardiac Death Epidemiology, Mechanisms, and Management

Sudden cardiac death (SCD) is a devastating complication of many forms of heart disease and on occasion presents in the absence of structural cardiac abnormalities. SCD caused by ventricular arrhythmias is a daunting public health problem with 200 000 to 450 000 events in the United States annually.1 There are many challenges in the definition, mechanisms, and management of SCD that will be addressed in the chapters of this compendium by leading experts in the field. The compendium will address gaps in our understanding of SCD and resuscitated SCD or sudden cardiac arrest (SCA) from genes to society and highlight opportunities for ongoing investigation. The epidemiology of SCD/SCA is dynamic and heterogeneous as they are the proximate causes of sudden death. Secular trends in incidence, mechanisms, and survival will be addressed, as well as the epidemiology of rarer heritable causes of SCD. The evolution of the causes of SCD/SCA and the relatively poor survival from out of hospital cardiac arrest have motivated studies to better assess risk and to implement strategies for prevention of underlying cardiovascular diseases. Basic science studies aimed at understanding the mechanisms of ventricular arrhythmias and the basis of pulseless electric activity (PEA) may afford new insights into to risk assessment and management of arrhythmic and nonarrhythmic causes of SCD/SCA and approaches to cardiac resuscitation. A foundational problem is the absence of a clear understanding of the rates of SCD. Differences in the methods of counting events yield substantial differences in rates of SCD. Differences in data sources yield differences in rates that are complicated by problems in case definition, in part the result of the heterogeneity and changing causes of SCD. Hayashi et al 2 present a contemporary and global epidemiological view of SCD as a public health problem, including a description of the incidence and survival …
Admission control schemes to provide class-level QoS in multiservice networks

In this work, we consider the scenario where diAerent classes of traAc with diAering bandwidth requirements are to be supported over a link with finite capacity. The network will be required to meet class-level quality-of-service (QoS) constraints that are specified as relations between the call blocking probabilities of these traAc classes. The network will also be required to maintain maximum throughput performance. We develop two diAerent admission control schemes that consider these two important criteria. First, we choose an objective that maximizes the throughput subject to the constraint that the maximum deviation from the desired class-level QoS is smaller than a certain pre-specified quantity. In the second approach, we choose an objective that minimizes the deviation from the desired class-level QoS subject to the throughput being greater than a pre-specified minimum value. We show how these problems can be converted to linear programming problems. We illustrate our schemes using numerical examples. ” 2001 Elsevier Science B.V. All rights reserved.
Separation of polycyclic aromatic hydrocarbon metabolites by γ-cyclodextrin-modified micellar electrokinetic chromatography with laser-induced fluorescence detection

Abstract Using a modified micellar buffer consisting of γ-cyclodextrin (γ-CD) and sodium dodecyl sulfate (SDS), we have obtained separations of hydroxy-polycyclic aromatic hydrocarbons (hydroxyPAHs). These compounds are oxidative products of mammalian PAH metabolism. The analytes were detected with a commercial laser-induced fluorescence (LIF) detector. A number of hydroxyPAH isomers could be separated by changes in γ-CD concentration. Baseline resolution of 12 hydroxyPAHs was obtained using 30 m M borate, 60 m M SDS and 40 m M γ-CD. The particular site substitution of the hydroxy group can produce changes in the hydroxyPAH fluorescence spectrum, and the effect of optical filter selection was studied for the LIF detection. The mass detection limits were in the (0.08–0.5)×10 −15 mol range. To our knowledge, this is the first report of the separation of metabolic products of PAHs (and several positional isomers) using γ-CD and micellar electrokinetic chromatography.
The Role of Attitudinal Familism in Academic Outcomes: A Study of Urban, Latino High School Seniors

The aim of this study was to examine the role of attitudinal familism on Latino high school students' academic grades, effort, motivation, and truancy. Results in this study reveal that having high attitudinal familism predicts fewer classes missed and greater academic effort. Also, when mothers' educational level is low, attitudinal familism is positively associated to students' academic grades. This study underscores the need for additional research on cultural measures that can help us better understand Latino adolescents' educational experiences.
Statistical properties of multiple-glint targets under laser illumination.

Statistical properties of the laser radar-received signal reflected from a finite number of target glints are obtained by using Monte-Carlo-type numerical simulations. Probability density functions for both direct-and coherent-detection processes are generated and shown following the theoretical prediction for an ideal diffuse surface. Additionally, the ratio of the mean signal power over its variance is calculated as a function of the aperture diameter ratio of the receiver over the transmitter for these two processes. The received signals are found to be linearly proportional to the number of contributing scatters for a far-field multiple-glint target.
Lateral hypothalamus destruction in infant rats produces consummatory deficits without sensory neglect or attenuated arousal.

Abstract Male and female albino rats sustained bilateral electrolytic destruction of the lateral hypothalamic area (LHA) at 10 days of age. After brain damage, physical growth, the ontogeny of sensorimotor behavioral capacity, and consummatory behavioral responses to specific regulatory challenges were repeatedly and systematically assessed for as long as 375 days of age. Bilateral LHA damage caused immediate cessation of suckling from the dam and necessitated maintenance by hand and tube feeding. The infant LHA rats were incapable of regulating body weight by intake of dry food and water alone when killed at 70 or 375 days of age. Although they eventually could maintain body weight by ad libitum intake of highly palatable wet diets, these rats displayed severe body weight reduction, impaired linear growth, and permanent consummatory deficits to specific regulatory challenges. Multimodal sensorimotor tests failed to reveal “sensory neglect” or “attenuated arousal” in the brain-damaged rats; however, a transient syndrome of motor deficits and hyperreactivity consistently appeared. These findings were in sharp contrast to the sensorimotor deficits seen in animals which sustain LHA damage after weaning or in adulthood. These data argue that sensory neglect or attenuated arousal is not necessary to production of consummatory deficits and, taken with other research, suggest that damage to intrinsic LHA neurons causes consummatory deficits whereas damage to fibers of passage causes sensorimotor impairment.
Glucose tolerance normalization following transplantation of pig pancreatic primordia into non-immunosuppressed diabetic ZDF rats.

Abstract Pancreas or pancreatic islet transplantation in humans is limited by organ availability, and success of the latter is negatively impacted upon by tissue loss post-transplantation and limited potential for expansion of beta cells. A way to overcome the supply and expansion problems is to xenotransplant embryonic tissue. Previously, we have shown that beta cells originating from embryonic day (E) 28 (E28) pig pancreatic primordia transplanted into the mesentery of streptozotocin-diabetic (type 1) Lewis rats engraft without the need for host immune-suppression and normalize glucose tolerance. Here we show long-term engraftment of pig beta cells within liver, pancreas and mesenteric lymph nodes post-transplantation of E28 pig pancreatic primordia into diabetic ZDF rats, a model for type 2 diabetes. Porcine insulin is present in circulation after an oral glucose load. Glucose tolerance is normalized in transplanted ZDF hosts and insulin sensitivity restored in formerly diabetic ZDF males. Release of porcine insulin in vitro from tissue originating in transplanted rats occurs within 1 min of glucose stimulation characteristic of first-phase secretion from beta cells. Of potential importance for application of this transplantation technology to treatment of type 2 diabetes in humans and confirmatory of our previous findings in Lewis rats, no host immunosuppression is required for engraftment of E28 pig pancreatic primordia.
Intermediate-Term Risk of Prostate Cancer is Directly Related to Baseline Prostate Specific Antigen: Implications for Reducing the Burden of Prostate Specific Antigen Screening

Purpose: Prostate specific antigen screening is controversial, as a large number of men must be screened annually to achieve a benefit. We sought to determine whether baseline prostate specific antigen could reliably predict subsequent risk of prostate cancer and risk of consequential prostate cancer.Materials and Methods: A multiethnic cohort of 2,923 prostate cancer-free men was recruited between 2000 and 2012, and followed for a median of 7.5 years. Baseline prostate specific antigen was stratified into 6 strata and relative hazards of prostate cancer detection for each prostate specific antigen stratum were estimated, adjusting for ethnicity, family history and age.Results: During followup 289 patients were diagnosed with prostate cancer. Men with baseline prostate specific antigen in the lowest stratum (0.1 to 1.0 ng/ml) were at greatly reduced risk for prostate cancer during followup. This half of the cohort with prostate specific antigen 1.0 ng/ml or less were at 3.4% (95% CI 2.1, 4.5) 10-year risk...
A floating gate CMOS signal conditioning circuit for nonlinearity correction

A high-speed signal conditioning circuit is presented that can be programmed for correction of nonlinearity in a sensor signal processing system. The function of the circuit is based on piecewise linear principles. Post-fabrication programming to adapt to existing nonidealities is done with floating gate devices fabricated in standard technology. Modeling of the sensor nonideality is not required. The circuit is a voltage-to-current converter with an input range of the full power-supply voltage swing. In a 12-module implementation in 2-µm CMOS technology less than 0.5% error over rail-to-rail input range and a speed of 10 MHz were achieved. The circuit is useful where a signal from a sensor with nonlinearity and high variation in its parameters has to be conditioned for further processing.
Potential implications of adjuvant endocrine therapy for the oral health of postmenopausal women with breast cancer

Current adjuvant treatment modalities for breast cancer that express the estrogen receptor or progesterone receptor include adjuvant anti-estrogen therapies, and tamoxifen and aromatase inhibitors. Bone, including the jaw, is an endocrine-sensitive organ, as are other oral structures. This review examines the potential links between adjuvant anti-estrogen treatments in postmenopausal women with hormone receptor positive breast cancer and oral health. A search of PubMed, EMBASE, CENTRAL, and the Web of Knowledge was conducted using combinations of key terms “breast,” “cancer,” “neoplasm,” “Tamoxifen,” “Aromatase Inhibitor,” “chemotherapy,” “hormone therapy,” “alveolar bone loss,” “postmenopausal bone loss,” “estrogen,” “SERM,” “hormone replacement therapy,” and “quality of life.” We selected articles published in peer-reviewed journals in the English. The authors found no studies reporting on periodontal diseases, alveolar bone loss, oral health, or oral health-related quality of life in association with anti-estrogen breast cancer treatments in postmenopausal women. Periodontal diseases, alveolar bone density, tooth loss, and conditions of the soft tissues of the mouth have all been associated with menopausal status supporting the hypothesis that the soft tissues and bone of the oral cavity could be negatively affected by anti-estrogen therapy. As a conclusion, the impact of adjuvant endocrine breast cancer therapy on the oral health of postmenopausal women is undefined. The structures of the oral cavity are influenced by estrogen; therefore, anti-estrogen therapies may carry the risk of oral toxicities. Oral health care for breast cancer patients is an important but understudied aspect of cancer survivorship.
Detecting postoperative hemorrhage or hematoma from administrative data: the performance of the AHRQ Patient Safety Indicator.

Background Patient Safety Indicator (PSI) 9, “postoperative hemorrhage or hematoma” (PHH), of the US Agency for Healthcare Research and Quality has been considered for public quality of care reporting. We sought to evaluate its performance in detecting true complications. Methods We conducted a retrospective, cross-sectional study of hospitalizations that met PSI 9 eligibility criteria. We sampled records flagged positive and negative by PSI 9 from a diverse set of 31 hospitals between February 2006, and June 2009. Trained abstractors reviewed medical records using standard instruments. We determined the sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of the indicator. Results Of 181 analyzable records flagged by PSI 9, 168 (93%; weighted PPV, 95% [95% confidence interval (CI), 90–98%]) involved an accurately coded event, but only 126 (70%; weighted PPV, 78% [95% CI, 58–90%]) represented true PHH. Thirty-two false positives involved only intraoperative hemorrhage. Among true positives, hypotension occurred in 28% and death attributed to the PHH in 4%. Thirty-two of 281 records flagged negative by PSI 9 (but enriched with questionably negative records) represented true PHH. The indicator's sensitivity was 42% (95% CI, 23–64%), specificity 99.9% (95% CI, 99.8–100%), and NPV 99.7% (95% CI, 99.0–99.9%). Modifying the indicator to include additional procedure codes improved both sensitivity (85% [95% CI, 67–94%]) and PPV (76% [95% CI, 60–88%]). Conclusion PSI 9 holds promise in detecting serious, possibly preventable complications. The indicator might be improved by specification of the 998.11 hemorrhage code to exclude purely intraoperative events and addition of procedure codes to the indicator's numerator criteria.
Generating Urban Lifestyle: The Case of Hong Kong New-Town Design and Local Travel Behaviour

The urban design of new towns embodies a movement and exchange system that has been consciously developed in relation to a set of expected human behaviours. In the history of new towns, these expectations have been variously fulfilled, but with rare investigations into the design causes. This study of Hong Kong new towns examines differences in travel behaviour between one early town and two later ones. While the general plans were quite similar and travel was expected to be the same in the towns, considerable differences were observed. Features of the town-centre design, details of the movement system and local environmental design all explain the differences in local behaviour. Differences in the size of the town, distance from the town centre and public transportation alternatives are all relatively unimportant in explaining the differences in local travel behaviour of residents. These findings point to the need for more empirical investigation into the effectiveness of urban design generally, and loca...
External radiation in the management of superior sulcus tumor

Thirty‐one patients with superior sulcus tumor (Pancoasťs syndrome) treated with radiation between 1967 and 1980 were reviewed. Doses ranged from 2000 to 7000 cGy delivered with a continuous schedule (23 patients) and a split course regimen (8 patients). The overall survival at 5 years was 18% (median, 17 months). Patients without bone erosion or scalene lymph node involvement (13 patients) had the best 5‐year survival rate of 40%. Local control tended to correlate with the total dose and tumor extent; doses below 5000 cGy or bone invasion were associated with a higher rate of local failure. Primary external radiation is not only useful for palliation but can also cure some patients with superior sulcus tumor. Copyright © 1984 American Cancer Society
Physics and media

Bits are bits has been the very successful mantra of the MIT Media Laboratory for its first decade. “Media” has historically meant film vs television vs radio vs newspapers vs books, each of these an entirely separate business, even in a company that does all. In retrospect it is now obvious how artificial it is to categorize information by the package that delivers it. These barriers are now being blown to bits, correctly focusing the interest where it should be: on how to gather, filter, transform, and deliver information to people in a form that is appropriate to the context. Ideas rather than pixels can and should be the primitive unit.
Contributions of peroxidase immunocytochemistry in the ultrastructural detection of membrane bound antigens.

Over the last 20 years specific membrane polypeptides, such as receptors, enzymes, and organelle-specific antigens, have been visualized in the electron microscope with 'pre-embedding' or 'postembedding' methods of tissue processing (Anderson et al., 1978; Louvard et al., 1982; Tokuyasu, 1986; Brown and Farquhar, 1989; Gonatas, J., et al., 1989; Roth, 1989; Chen et al., 1989). With 'pre-embedding' methods, tissue sections or cells are fixed and 'permeabilized' with a suitable detergent prior to the application of the labeling probe; the labeling probe is then visualized in the light and electron microscopes with horseradish peroxidase (HRP), which may be coupled directly to the labeling probe, or to a second ligand (Guesdon et al., 1979; Brown and Farquhar, 1989). The detection of HRP in the light and electron microscopes is then accomplished with the classic diaminobenzidine (DAB) reaction of Graham and Karnovsky (1966). In 'postembedding' immunocytochemistry, ceils or
Magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a systematic review and meta-analysis.

Objective This study aimed to perform a structured meta-analysis of all eligible studies to assess the overall diagnostic use of magnetic resonance cholangiopancreatography (MRCP) alone or with secretin enhancement (secretin-enhanced MRCP [S-MRCP]) in the detection of pancreas divisum. Methods Two authors independently performed a comprehensive search of PubMed, MEDLINE, and the Cochrane Library from inception to September 2013. Studies were included if they allowed construction of 2 × 2 contingency tables of MRCP and/or S-MRCP compared with criterion standard. DerSimonian-Laird random effect models were used to estimate the pooled sensitivity, specificity, specificity, and quantitative receiver operating characteristics. Results Of 51 citations, 10 studies with 1474 patients were included. Secretin-enhanced MRCP had a higher overall diagnostic performance than MRCP (S-MRCP: pooled sensitivity, 86% [95% confidence interval (CI), 77%-93%]; specificity, 97% [95% CI, 94%-99%]; and area under the curve, 0.93 ± 0.056 compared with MRCP: sensitivity, 52% [95% CI, 45%-59%]; specificity, 97% [95% CI, 94%-99%]; and area under the curve, 0.76 ± 0.104). Pooled diagnostic odds ratios were 72.19 (95% CI, 5.66-938.8) and 23.39 (95% CI, 7.93-69.02) for S-MRCP and MRCP, respectively. Visual inspection of the funnel plot showed low potential for publication bias. Conclusions Secretin-enhanced MRCP has a much higher diagnostic accuracy than MRCP and should be preferred for diagnosis of pancreas divisum.
Observational Learning and Practice Variability.

Abstract Two factors said to influence motor learning are mode of information feedback and conditions of practice. The current investigation explored certain aspects of those factors for the specific purpose of gaining insight into processes underlying the observational learning of motor skills. Design was a practice (variable/constant) X information mode (modeling/physical) X trials factorial. Physical practice occurred in the absence of vision. Dependent variable was an angular positioning task. The acquisition phase consisted of 60 KR trials. The physical conditions received KR based on their own response outcomes, while the modeling groups heard model-contingent KR. Subsequent no-KR transfer to a new target located outside the range of previous practice supported the notion of the superiority of variable over constant practice during observational learning. The results also indicated that subjects who observed a model who had practiced under variable conditions were later able to perform in a manner q...
Tallgrass prairie management and bird nest success along roadsides

The attributes of roadside vegetation, an important bird habitat in grassland ecosystems, have been shown to affect bird abundance, distribution composition, and diversity, yet there are relatively few works on reproductive success of birds nesting along roadsides. Because roadsides are linear habitats, management at the landscape scale can affect nest success in roadsides through bottom-up and top-down effects. In northeastern Oklahoma tallgrass prairie is subjected annually to prescribed spring fires. In the short term fires can alter both arthropod abundance and predator access to nests. We explored effects of burning on bird nest success with a five-year study along roads that traversed tallgrass prairie habitat. Using data from ∼1400 nests of 23 species, we generated nest survival curves for groups of altricial species defined by nest substrate (ground, shrub, tree, or culvert). We then determined if these curves were affected by management practice (spring burning), food abundance (arthropod biomass), and habitat attributes (tree density and height). Nest substrate had a large effect on nest success: despite their shorter nest exposure period, ground nests were least successful and culvert nests were most successful. An increase in arthropod biomass following burning was possibly the cause for the increased nest success in burned plots, regardless of substrate, suggesting bottom-up control. Tree height and nest height were correlated positively with nest success, whereas tree density had no effect. Conversely, nest predation rates were correlated negatively with nest success, with ground nests experiencing the highest predation, culvert nests the lowest. Our results suggest that burning may increase nest success through bottom-up processes, but some species may not benefit from the increase in food abundance as a result of a concomitant increase in predation.
High temperature mechanical properties of single phase alumina

The creep properties of a commercial, single phase aIurnina have been determined in the temperature range of 1623 to 1723 K. The stress exponent,n, in the relationship ɛ ∝ σ n was determined to be 1.9 and the true activation energy was found to be 635 kJ mol−1. Normal primary stage creep transients were observed up to strains of 1%. At low stresses, steady-state conditions were not obtained due to the occurrence of concurrent grain growth. It is shown that the steady state creep results are consistent with the occurrence of an interface controlled diffusionaI creep mechanism.
Rabbit antibodies to ovine submaxillary mucin. detection, specificity and cross-reactivity

Abstract A newly developed passive hemagglutination inhibition technique was used to show that at least 2 families of antibodies are generated after immunization of rabbits with ovine submaxillary mucin (OSM)§ in homogeneous form. OSM-specific antibodies were non-precipitating in agar and liquid phase, easily detectable by a passive hemagglutination technique, and directed primarily to the carbohydrate side chain. In the case of subcutaneous immunization with OSM emulsified in complete Freund's adjuvant, the immunodominant determinants were the disaccharide prosthetic group (NAN-galNAc-protein) and a desialized moiety (galNAc-protein) which comprises about 14% of total prosthetic groups in OSM as isolated. Modest changes in the terminal sialic acid were associated with reduced interaction with anti-OSM sera. By contrast, intravenous immunization with OSM coupled to red blood cells elicited an additional family of antibodies with specificity for apo-protein. Explanations for this switch in specificity are considered.
Inventory Control with a Randomly Available Discount Purchase Price

A mathematical model is developed for a basic single-commodity storage system in which the stock controller is faced with a randomly fluctuating purchase price. High- and low-price periods are defined and a purchasing policy is specified which depends upon both the number of units in storage and the price period in which the system is operating. For the case of random demand the limiting stochastic behaviour of the system is obtained and the cost of operating the system is derived.
Human Cytochrome P450 21A2, the Major Steroid 21-Hydroxylase STRUCTURE OF THE ENZYME·PROGESTERONE SUBSTRATE COMPLEX AND RATE-LIMITING C–H BOND CLEAVAGE

Abstract Cytochrome P450 (P450) 21A2 is the major steroid 21-hydroxylase, and deficiency of this enzyme is involved in ~ 95% of cases of human congenital adrenal hyperplasia, a disorder of adrenal steroidogenesis. A structure of the bovine enzyme we previously published (Zhao, B. et al. (2012) J. Biol. Chem. 287, 10613-10622), containing two molecules of the substrate 17alpha-hydroxyprogesterone, has been used as a template for understanding genetic deficiencies. We have now obtained a crystal structure of human P450 21A2 in complex with progesterone, a substrate in adrenal 21-hydroxylation. Substrate binding and release were fast for human P450 21A2 with both substrates, and pre-steady-state kinetics showed a partial burst but only with progesterone as substrate and not 17alpha-hydroxyprogesterone. High intermolecular non-competitive kinetic deuterium isotope effects on both kcat and kcat/Km (5-11) were observed with both substrates, indicative of rate-limiting C-H bond cleavage and suggesting that the juxtaposition of the C21 carbon in the active site is critical for efficient oxidation. The estimated rate of binding of the substrate progesterone (kon 2.4 x 107 M-1 s-1) is only ~ 2-fold greater than the catalytic efficiency (kcat/Km 1.3 x 107 M-1 s-1) with this substrate, suggesting that the rate of substrate binding may also be partially rate-limiting. The structure of the human P450 21A2-substrate complex provides direct insight into mechanistic effects of genetic variants.
The tensile strength of 339 aluminum reinforced with Kaowool fibers: A comparison of T5 and T6 heat treatments

This study compares the effects of T5 and T6 heat treatment on the tensile strengths of both KAOWOOL fiber reinforced and unreinforced 339 aluminum. The 339 Al-T6 is stronger than 339 Al-T5 (as expected), but for a KAOWOOL/339 Al composite, the T5 condition is substantially stronger than the T6. The controlling parameter is the strength of the aluminum dendrites, which in turn is proportional to the concentration of magnesium retained in the dendrites. In the T5 condition, more than half of the magnesium is in the form of large intermetallics in both the unreinforced alloy and the KAOWOOL/339 Al composite. During a T6 heat treatment, magnesium in the intermetallics is redissolved. In the unreinforced T6 alloy, this additional magnesium is retained in and strengthens the dendrites. But in the T6 composite, the magnesium segregates extensively to the KAOWOOL/aluminum interfaces depleting and softening the dendrites. This factor alone is sufficient to account for the low strength of the T6 composites. The tensile strengths of both the T5 and T6 composites correspond to the calculated values for a perfectly bonded system.
THE COMPLEMENTARY USE OF ATOM PROBE FIELD ION MICROSCOPY AND ANALYTICAL TRANSMISSION ELECTRON MICROSCOPY FOR THE STUDY OF A Ni-BASE SUPERALLOY

Compositions of the γ, γ' and DO22 phases in the nickel-base superalloy RSR 143 (76Ni-13A1-9Mo-2Ta, at. %) have been determined via atom probe field-ion microscopy (APFIM) as 76Ni-6A1-18Mo, 67Ni-25A1-4Mo-4Ta and be 73Ni-4A1-20Mo-3Ta respectively. Using energy dispersive x-ray spectroscopy in the analytical transmission electron microscopy (TEM), the composition of the γ' phase (69Ni-22A1-4Mo-5Ta) was found to be similar to that determined by APFIM. The deviation of the DO22 composition from Ni3Mo is in agreement with the prediction of a recent TEM study (Martin et al, 1980, 1982).
The impact of statin and macrolide use on early survival in patients with pneumococcal pneumonia.

Abstract Background Mortality in pneumococcal pneumonia remains high despite early antibiotic eradication of bacteria. Most deaths occur within the first week, the time of peak inflammatory responses. Statins and macrolides have broad immunosuppressive activity; their impact, separately and together, on survival in patients with pneumococcal pneumonia was evaluated. Methods All patients with pneumococcal pneumonia seen at a single medical center from 2000 through 2010 were included in this retrospective cohort study. A multivariate-adjusted Cox proportional hazard model was used to evaluate survival. Results Of 347 patients with pneumococcal pneumonia, 90 (26%) were taking a statin at presentation and 126 (36%) were started on treatment with a macrolide. Thirty-two (9%) statin users were treated with a macrolide. Statin users were older than non-statin users, with a higher prevalence of diabetes, coronary artery disease and chronic kidney disease and a lower prevalence of alcohol consumption and liver disease. Statin users had higher mean Pneumonia Patient Outcomes Research Team scores. Patients treated with a macrolide were not different from those who received other antibiotics. The risk of mortality among statin users was reduced at 7, 14, 20 and 30 days after admission. Mortality was not reduced in patients treated with a macrolide or with a macrolide plus a statin compared with those who did not receive a macrolide. Conclusions Patients who are receiving statins at the time of admission for pneumococcal pneumonia have better clinical outcomes than those who are not. Treatment with a macrolide does not appear to confer a survival benefit.
Effects of age, reproductive status and ambient temperature on skin temperature regulation in the female rat.

Abstract In the present study, we evaluated a large population of aged Long-Evans female rats for the occurrence of spontaneous tail skin temperature (TST) surges. Young (5–7 months) normally cycling (NC) rats and aged (19–29 months), repeated pseudopregnant (PP) and constant estrous (CE) rats were placed in an environmentally controlled room with ambient temperatures of 24–25°C or 29–30°C and TST was monitored at 5 min intervals for 2 h. In young NC and aged PP rats, the incidence of TST surges (flushes) was 8–17% at low and 28–33% at high ambient temperature. Old CE rats exhibited a flushing incidence of 21% and 74% at ambient temperatures of 24–25°C and 29–30°C, respectively. The observed flushing episodes did not differ in their duration or amplitude among the three groups of rats. However, at both low and high ambient temperature, the frequency of flushes were significantly higher in old CE rats. Collectively, these data indicate that reproductive status, rather than age, is the important determinant of TST stability in the female rat. Further, elevated estrogen associated with the CE state may compromise, while elevated progesterone associated with the PP state has a protective effect on the stability of TST in the female rat.
Psyllium reduces relative calcium bioavailability and induces negative changes in bone composition in weanling Wistar rats

Certain dietary fibers may decrease calcium bioavailability. The objective of this study was to determine the bioavailability of calcium from different amounts and sources of psyllium. Psyllium fiber sources were purified powdered psyllium seed husk, Metamucil® brand fiber supplement, and All-Bran® Bran Buds® cereal. Sixty-six female weanling rats were fed diets containing 5% or 10% purified psyllium, 5% or 10% Metamucil®, 5% or 10% All-Bran® Bran Buds®, or a control diet containing 5% cellulose for 4 weeks. Treatment diets resulted in lower body weight gain, increased fecal weight, and decreased apparent calcium absorption. Relative calcium bioavailability was reduced to less than 90% by diets containing 10% fiber from psyllium and 10% fiber from Metamucil®. Treatment diets induced significant negative changes in calcium, hydroxyproline, and hexosamine content of hind limb bones and mandibles. These results suggest that calcium bioavailability is reduced with an increased intake of soluble fiber from sources of psyllium.
The high temperature oxidation of nickel

Abstract The oxidation of pure Ni has been studied over a temperature range of 1173–1573 K under 1.01 bar oxygen. The oxidation kinetics, the oxide growth and the metal recess obey parabolic time relationships. The dependence of the parabolic rate constant for oxidation can be expressed as: K p = 7.95 × 10 −2 exp (− 220.9/ RT ) with the activation energy in kJ mole −1 . An attempt is made to calculate K p in terms of diffusion parameters. These calculated values compare well with those measured experimentally.
The Managing of the Presidency Applying Theory-Driven Empirical Models to the Study of White House Bureaucratic Performance

We argue that scholars of the presidency should begin to apply their rich descriptive understanding of White House organization and personnel to questions of causality. To help guide this effort, we offer a theory-driven empirical model that explains organizational performance. Importing theory from the public management literature, we show how scholars can use the Meier-O'Toole (MO) model to explain performance outcomes and dynamics for key political and policy functions within the institutional presidency. We introduce the MO model and discuss its potential impact on the field of presidency studies.
A data-integrated simulation model to forecast ground-level ozone concentration

Elevated ground-level ozone is hazardous to people’s health and destructive to the environment. This research develops a novel data-integrated simulation to forecast ground-level ozone (SIMGO) concentration based on a real data set collected from seven monitoring sites in the Dallas-Fort Worth area between January 1, 2005 and December 31, 2007. Tree-based models and kernel density estimation (KDE) were utilized to extract important knowledge from the data for building the simulation. Classification and Regression Trees (CART), data mining tools for prediction and classification, were used to develop two tree structures in order to forecast ground-level ozone based on factors such as solar radiation and outdoor temperature. Kernel density estimation is used to estimate continuous distributions for the ground-level ozone concentration for seven days in advance. One week forecasts obtained from SIMGO for different months of a year is presented.
Calcium-dependent Binding of S100C to the N-terminal Domain of Annexin I

Abstract The annexin family of proteins is characterized by a conserved core domain that binds to phospholipids in a Ca-dependent manner. Each annexin also has a structurally distinct N-terminal domain that may impart functional specificity. To search for cellular proteins that interact with the N-terminal domain of annexin I, we constructed a fusion protein consisting of glutathione S-transferase fused to amino acids 2-47 of human annexin I (GST-AINT; AINT = annexin I N-terminal). Extracts from metabolically labeled A431 cells contained a single protein (M 10,000) that bound to GST-AINT in a Ca-dependent manner. A synthetic peptide corresponding to amino acids 2-18 of annexin I inhibited the binding of the 10-kDa protein to GST-AINT with half-maximal inhibition occurring at 15 μM peptide. In cellular extracts, endogenous annexin I and the 10-kDa protein associated in a reversible Ca-dependent manner. Experiments with other annexins and with N-terminal truncated forms of annexin I indicated that the 10-kDa protein bound specifically to a site within the first 12 amino acids of annexin I. The 10-kDa protein was purified from human placenta by hydrophobic and affinity chromatography. Amino acid sequence analysis indicated that the 10-kDa protein is the human homologue of S100C, a recently identified member of the S100 subfamily of EF-hand Ca-binding proteins.
Spectra and structure of silicon-containing compounds. XXXIII — Raman and infrared spectra, conformational stability and vibrational assignment of chloromethylsilyl bromide†

The Raman spectra (3200 to 30 cm−1) of liquid and solid and the infrared spectra of gaseous and solid chloromethylsilyl bromide, ClCH2SiH2Br, were recorded. Utilizing three conformer pairs from the Raman spectrum of the liquid along with their ab initio predicted activities, the enthalpy difference of 216 ± 22 cm−1 (2.58 ± 0.26 kJ mol−1) was obtained with the trans conformer the more stable form. Variable temperature (−105 to 150° C) studies of the infrared spectra of the sample dissolved in liquid krypton were carried out and from these data, the enthalpy difference was estimated to be 250 ± 50 cm−1 (2.99 ± 0.60 kJ mol−1), again with the more stable form being the trans conformer. These values are consistent with the prediction from ab initio calculations both at the Hartree–Fock level and with full electron correlation by the perturbation method to second order. It is estimated that 37 ± 6% of the sample is in the gauche form at ambient temperature. Only the trans conformer remains in the spectra of the solid. A complete vibrational assignment is proposed for the trans conformer and also several of fundamentals of the gauche conformer based on infrared band contours, relative intensities, depolarization values and group frequencies, which is supported by normal coordinate calculations utilizing the force constants from the ab initio MP2/6–31G(d) calculations. The optimized geometries and conformational stabilities were also been obtained from ab initio calculations utilizing two additional basis sets with full electron correlation by the perturbation method. Estimates were made of the r0 structural parameters based on the predicted structural parameters from ab initio MP2/6–311 + G(d,p) calculations. The results are discussed and compared with some corresponding results for some related molecules. Copyright © 2002 John Wiley & Sons, Ltd.
Enhanced anti-HIV efficacy of indinavir after inclusion in CD4-targeted lipid nanoparticles.

BACKGROUND Combination drug therapy has reduced plasma HIV to undetectable levels; however, drug-sensitive virus persists in patients' lymphoid tissue. We have reported significant lymphoid tissue drug localization with indinavir-associated lipid nanoparticles (LNPs). Our current objective is to evaluate whether additional enhancement is achievable by targeting these particles to CD4-HIV host cells. METHODS We characterized 2 peptide-coated (CD4-BP2 and CD4-BP4) drug-associated LNPs and demonstrated CD4-cell specificity. Drug-associated LNPs expressing polyethyleneglycol were exposed on HIV-2-infected cells under dynamic conditions that emulated lymph node physiology for 15, 30, and 60 minutes at concentrations from 0 to 25 μM and evaluated for antiviral activity and cell-associated drug concentrations. The specificity of CD4-mediated enhancement of indinavir LNPs antiviral activity was evaluated by blocking with anti-CD4 antibody. RESULTS Inclusion of CD4-binding peptides on LNPs enhanced antiviral activity for all incubation conditions, compared with control particles or soluble drug (eg, 60 minutes exposure, EC50 = 0.12-0.13 vs. 0.46 μM for targeted nanoparticles vs. soluble drug). The CD4-BP4 peptide exhibited higher efficiency in eliciting antiviral activity than CD4-BP2-coated particles (EC50 = 7.5 μM vs. >25 μM at 15 minutes drug exposure). This enhancement seems to be driven by CD4 availability and cell-associated indinavir concentrations, as blocking of CD4 significantly ablated indinavir efficacy in targeted particles and indinavir concentrations reflected the observed anti-HIV activity. CONCLUSIONS We constructed CD4-targeted LNPs that provide selective binding and efficient delivery of indinavir to CD4-HIV host cells. Inclusion of polyethyleneglycol in LNPs would minimize immune recognition of peptides. The enhancement of anti-HIV effects is effective even under limited time exposure.
Heuristic methods for optimal electric vehicle charging scheduling in smart grid

The increasing popularity of electric vehicles (EV) will pose great challenge to the nation’s existing power grid by adding extra load during evening peak hours. This paper develops a centralised optimal charging scheduling (OCS) model with a mixed integer non-linear programme to mitigate the negative impact of extra load from EVs on the power grid. The objective of the OCS model is to minimise the energy cost of the entire system, which essentially levels the load of the entire power grid throughout a day under the dynamic pricing environment. Furthermore, a rolling horizon heuristic algorithm is proposed as an alternative solution that addresses large-scale OCS instances. Finally, when centralised scheduling is impractical, this paper proposes a decentralised optimal charging heuristic using the concepts of game theory and coordinate search. Numerical results show that the optimal charging scheduling model can significantly lower the total energy cost and the peak-to-average ratio (PAR) for a power system. When compared to uncontrolled charging, the decentralised charging heuristic yields considerable energy savings as well, although not as efficient as the centralised optimal charging solutions.
Lysosomes in malanin phagocytosis and synthesis

THERE are two types of pigmented cells in normal human skin, the junctional dendritic melanocyte and the intradermal melanosome-phagocytosing melanophage (Fig. 1). In contrast to the melanocyte and its contained melanosome synthesizing process which have been thoroughly investigated, the cellular physiology of the melanophage remains unknown despite recent advances in electron microscopy and gradient biochemistry. The two cells containing melanin appear similar under the light microscope but electron microscopy reveals definite structural differences. The normal melanocyte contains various stages of melanosome synthesis occurring individually in close association with the Golgi apparatus. On the other hand, the actively phagocytosing melanophage concentrates its melanosomes1–3 as degradative conglomerates into specially developed phagocytic vacuoles structurally resembling the lysosomes found in such tissues as kidney, liver and pancreas4,5. Lysosomes were found to be rich in acid phosphatase4,5, which predicted the presence of this hydrolytic enzyme in the phagocytic vacuoles of the dermal melanophage6. We found subsequently that acid phosphatase activity is concentrated in the melanophages and that there is little or no such activity in the melanocytes at the epidermal–dermal junction7. On the other hand, the melanophages contain little if any tyrosinase while the junctional melanocytes are shown to contain an abundance of this oxidative enzyme, primarily within the premelanosomes8. It is further observed with the electron microscope, using the modified Gomori reaction, that the electron opaque accumulation of lead sulphide resulting from acid phosphatase activity occurs primarily in the melanosome-concentrating phagocytic vacuoles of the melanophages7.
Derivation of fluorine-containing pyridinedicarboxylates. III: Regio-selective anion chemistry at the 2- and 4-position

In contrast of Part II of the series, 4-alkyl-2-(difluoromethyl)-6-(trifluoromethyl)-3,5-pyridinedicarboxylates, 1, were reacted with various strength bases to effect regio-selective reaction of electrophiles at either the benzylic carbanion of the 4-position, or at the 2-(difluoromethyl)carbanion. Weaker bases up to and including potassium butoxide or lithium bis(trimethylsilylamide) effected reaction of 1 at the 4-position to produce 2 and 3 by Stobbe-type condensations of aldehydes and ketones. In similar manner carbon disulfide, carbon dioxide, alkyl halides, silyl halides, and hexachloroethane produced the highly functionalized derivatives 4-10. In contrast, use of lithium diisopropylamide and like bases selectively effected carbanion formation at the 2-position to form, with the cited electrophiles and others, substitution products 11. The latter were further derived to the highly functional materials, 12-19.