cssi/SciSciGPT-SciSciNet huggingface dataset:
How is 1,1-dimethyl-1-silacyclopent-2-ene formed in the addition of dimethylsilylene to 1,3-butadiene? Evidence for a pathway via a vinylsilirane intermediate

Addition of dimethylsilylene Me2Si: to 1,4-dideutero-l,3-butadiene in gas-phaee flow pyrolysis experimenss leads to the formation of 2,5-dideutero-1, 1-dimethyl-1-silacyclopent-3-ene and 4,5-dideutero-1,1-dimethyl-1-suacyclopent-2-ene. Pyrolysis of the silacyclopent-3-ene product leads to the same silacyclopent-2-ene. This labelling pattern for the silacyclo-pent-2-ene product is compelling evidence for its formation via carbon-carbon bond-cleavage in a vinylsilirane intermediate, and for the intermediacy of the vinylsilirane in the silylene addition leading to the silacyclopent-3-ene as well.
The recipe for promising practices in community colleges

This study identifies and examines the key practices of California community college programs that have demonstrated success in improving (or that have shown significant potential to improve) the achievement of underrepresented groups whose educational attainment often lags behind the attainment of relatively well-off White students. Unlike many examinations that focus only on the transfer mission, this study includes other vital areas of the community college, including workforce preparation and developmental education. Study findings reveal that the practices of these programs had four common characteristics: cohesion—the ability of program personnel to operate as a unit in which behaviors and actions mesh or are rationally consistent; cooperation —the degree to which program personnel work together toward common goals and form good working relationships with each other and with students; connection—the ability of program personnel to sustain interdependent relationships with internal and external entit...
Conditions for the bilateral transfer of monocular learning in chicks.

Abstract Following the unilateral ablation of telencephalic centers critical for visual learning, baby chicks were monocularly trained first to avoid an aversive stimulus and then to extinguish the acquired aversive reaction. Chicks learned the first task equally well whether through the eye ipsilateral or contralateral to surgery. The second task, however, was learned only by chicks trained to extinguish through the eye ipsilateral to surgery. Thus, whereas memory for the aversive experience seems to be laid down equally well in both the hemispheres contralateral and ipsilateral to the trained eye, memory for extinction can be established only in the hemisphere contralateral to the eye trained in that task. In a group of unoperated chicks, monocularly learned extinction was found not to be retrievable through the untrained eye; the aversive response task, however, shows complete transfer. This suggests that interocular transfer can only be achieved in those situations in which monocular training results in the formation of bilateral engrams. An involvement of anatomically distinct mechanisms for learning the aversive conditioning and the extinction is discussed as a possible determinant of the differences in bilateral transfer found for these tasks.
The Effects of an Auditory Versus a Visual Presentation of Information on Soldier Performance

Abstract : This report describes a field study designed to measure the effects of an auditory versus a visual presentation of position information on soldier performance of land navigation and target acquisition tasks. Measures of situational awareness, stress, cognitive performance, and workload were also obtained. In the auditory mode, position information was presented in verbal messages. In the visual mode, the same information was provided in text and graphic form on a map of the area of operation presented on a helmet-mounted display (HMD). During the study, 12 military volunteers navigated densely wooded unmarked paths that were 3 km long. Although no differences were found between the two display modes in the frequency at which navigational and other tactical information was accessed, the analysis of responses to probe questions indicated that participants maintained a greater awareness of position with respect to waypoints, targets, and other units when information was presented visually than when information was presented auditorily in verbal messages. In the auditory mode, as the participants' perceptions of time demands increased, post-test scores on a logical reasoning task tended to be higher than pre-test scores. Although visual presentation of information appeared to enhance position awareness, differences between the two display modes in navigation and target acquisition performance were not found to be statistically significant. The findings of the investigation suggest differences in cognitive processing requirements between the two displays and the impact of attentional focus and practice on cognitive performance.
Interesting Transformations of Thiocamphor

Thiocamphor has been found to furnish bornane, camphor, isoborneol, isobornylthiol, bornylthiol, tetrahydro-bis-(1,7,7-trimethylbicyclo[2.2.1]heptyl)-3,3′-disulfide, and three isomeric bis-(1,7,7-trimethylbicyclo[2.2.1]heptyl)-3,3′-dithiols when treated with NaBH4 either in dry THF or dry diethylene glycol diethyl ether. The origins of the above interesting compounds and their mass spectral characterization are presented in this article.
Change of the weak-field properties of Pb(ZrTi)O3 piezoceramics with compressive uniaxial stresses and its links to the effect of dopants on the stability of the polarizations in the materials

The properties of several Pb(ZrTi)O{sub 3} (PZT) piezoceramics under compressive uniaxial stresses were characterized. It was observed that uniaxial stresses have a marked effect on the soft PZT materials, including reducing the piezoelectric coefficients and depoling the samples at relative low stress levels. The effect of the uniaxial stresses on the properties of hard PZT{close_quote}s is more complicated because the domain structure of the materials can be changed substantially without depoling the samples. Therefore, under a compressive stress along the poling direction, the piezoelectric and electromechanical coupling factor can be increased markedly due to both the increased non-180{degree} domain boundary motions and the deaging effect. In addition, the experimental results support the notion that the difference between a hard PZT and a soft PZT lies in the types of defects introduced by dopants. Immobile defects create frustrations in the lattice and result in a soft behavior, and mobile defects stabilize the polarization and produce a hard behavior. {copyright} {ital 1997 Materials Research Society.}
The Changing Information Seeker: A Study of Attitudes Toward Product Test Reports–1970 and 1976

Systematic samples of subscribers to Consumer Reports were surveyed in 1970 and 1976 to obtain their evaluations of the information they had received. Responses are compared between the two years, stressing the environmental context of each measure. Attitudes toward characteristics of the information and satisfaction with Consumer Reports are found to be high in both years, but ratings are significantly less favorable in 1976. Implications for Consumers Union management, other policy-makers, and further research are discussed.
Evaluation kernels for microprocessor performance analyses

Abstract Contemporary microprocessors offer several sophisticated technical features that were once the exclusive domain of large mainframes. The implementation of these capabilities in VLSI motivates the evaluation of these microprocessors at various hierarchical levels. This paper compares the basic architectures, the instruction sets and finally the overall performance of the three leading 16-bit microprocessors.
Heat Adaptation Alters Escherichia coli O157:H7 Membrane Lipid Composition and Verotoxin Production

The influence of heat adaptation (growth at 42 and 45°C) on changes in membrane lipid composition and verotoxin concentration of Escherichia coli O157:H7 (ATCC 43895), an rpoS mutant of ATCC 43895 (FRIK 816-3), a verotoxin mutant E. coli O157:H7 (B6-914), and nonpathogenic E. coli (ATCC 25922) was investigated. D values (57°C) of heat-adapted cells were up to 3.9 min longer than those of control cells for all four strains. Heat adaptation increased the amounts of palmitic acid (16:0) and cis-vaccenic acid (18:1ω7c) in membrane lipids of ATCC 43895 and the rpoS mutant, whereas there was a reduction and no change in the amount of cis-vaccenic acid in nonpathogenic and verotoxin mutant E. coli, respectively. The ratio of palmitic to cis-vaccenic acids decreased in ATCC 43895 and in the rpoS mutant, whereas the ratio increased in nonpathogenic E. coli and was not different in the verotoxin mutant with elevated growth temperature. Total verotoxin concentration decreased due to a reduction in intracellular verotoxin amount in heat-adapted ATCC 43895 and rpoS mutant strains. However, extracellular verotoxin concentration increased in heat-adapted cells. The rpoS gene did not influence membrane lipid composition changes although it did affect heat resistance. Results suggest that increased membrane fluidity may have caused increased verotoxin secretion.
Steps and spikes in current‐voltage characteristics of oxide/microcrystallite‐silicon/oxide diodes

SiO2/microcrystallite‐Si/SiO2 diodes with different contact window sizes were fabricated and studied at room temperature, 77 K, and 4.2 K. Steps were observed in the current‐voltage (I‐V) characteristics at all three temperatures. These steps would appear for a certain number of measurements, depending upon measurement temperature, and then were replaced by a smooth electrical breakdown I‐V characteristic. Data analysis indicates that the steps in the I‐V characteristics are due to local electrical breakdowns along the edge of metal contacts instead of electron resonant tunneling through the structure. Surprisingly, however, in one diode, three repeatable spikes, instead of steps, were observed at 4.2 K; this cannot be satisfactorily explained in terms of electrical breakdown, and seems rather like electron resonant tunneling.
Zero net house: Preliminary assessment of suitability for Alberta

The author examines the zero net house (ZNH) concept and makes preliminary assessments of suitability for Alberta. The aim is to improve energy efficiency and reduce green house gas (GHG) emissions. The author compares a theoretical ZNH model, constructed from available historical data; construction data; and trends of consumption in Alberta to models of average class house (ACH) and industry-endorsed technical performance standard (R-2000). Results indicate that ZNH is capable of achieving more GHG reduction levels and reduces energy requirements of occupants compared to ACH and R-2000. Construction costs of ZNH in Alberta exceed that of ACH by 15% but falls within literature's range. With energy escalation rate of 15% per year, the ZNH savings could potentially allow occupants to pay off a significant part of the ZNH.
516 First Intention N-Sippv Vs. N-Cpap in Preterm Infants Complicated by Respiratory Distress Syndrome

Background and aims: Nasal intermittent positive pressure ventilation (N-SIPPV) can constitute a new ventilatory mode for RDS treatment. In this regard, N-SIPPV has been shown to be safe and more effective than N-CPAP when used in the weaning from MV. However, data comparing the effectiveness of N-CPAP versus N-SIPPV as best first intention therapeutic strategy for RDS treatment of ELBW/VLBW infants are to date lacking. The present study investigates whether first intention N-CPAP or N-SIPPV can constitute a valid option of ventilation in the respiratory management of RDS. Methods: From January 2005 to January 2009 we performed a prospective case-control study in 92 infants ( 0.05, for all) have been shown in the two different ventilatory strategies. However, the length of nasal ventilation support was higher in N-SIPPV group, although not statistically significant (P>0.05). Conclusions: The present data provide evidence that first intention non-invasive ventilatory strategy could be successful in ELBW/VLBW infants undependently form N-SIPPV and/or N-CPAP devices.
A heuristic model of grieving after high-grief deaths

Abstract Building on evidence I offered earlier (Horacek, 1991), I develop a heuristic model of grieving that challenges the assumptions that grieving is time limited and that the bereaved should totally detachet or detach themselves from emotional ties to the deceased. This model includes three sets of reactions and grief tasks. Although many reactions will fade and some will disappear, and most grief tasks can be completed, this model states that the basic loss continues to exist like a phantom limb after amputation. Unlike unresolved m chronic grief, this continuing giving or loss does not significantly impair everyday functioning. The implications of this model are discussed.
Solid polymer/salt electrolytes based on linear poly((N-2-cyanoethyl)ethylenimine)

Abstract There has been growing interest in the structure, properties, ionic association, and conductivity in poly(acrylonitrile) (PAN)/salt systems and its structural analogues. We have developed a simple procedure to cyanoethylate the nitrogen atoms (>95% by 1H-NMR) of linear poly(ethylenimine) (PEI) to form poly((N-2-cyanoethyl)ethylenimine) (PCEEI). IR studies indicate that, like PAN, a second nitrile stretching band develops for PCEEI on addition of LiTf, indicating coordination of nitrile groups to Li cations. However, spectroscopic data on the triflate ions indirectly suggest that, unlike PAN/LiTf systems, PCEEI systems contain significant proportions of “free” Li cations at high LiTf concentrations. Initial results indicate the RT ionic conductivity in the PCEEI systems is on the order of 10−8 S cm−1 at a composition of N:Li=6:1 and was found to be largely independent of LiTf concentration over a range of sample concentrations. The nature of the relative concentrations of ionic species of LiTf in PCEEI was determined with infrared spectroscopy. Results of room temperature and variable temperature complex impedance measurements are presented.
Sunk Cost, Emotion, and Commitment to Education

The influence of prior, irretrievable, investment (sunk cost) on commitment to a course of education was investigated. The moderating effects of the emotions of anger and fear over this commitment decision were also investigated. A total of 425 participants (214 male) with a mean age of 19.92 years were recruited from an undergraduate population. A computer program simulated the process of arranging to undertake a course of education. Participants were induced to feel either anger or fear and, then, invested one of three amounts of sunk cost (under budget, on budget, or over budget) to signing up for a course. Participants then decided how much time they wished to commit to this course or to an alternative, identical course with a better chance of success. Results revealed a significant sunk cost effect of prior investment on commitment to a course of education. Results also revealed that anger increased the magnitude of this sunk cost effect. Results did not reveal any effect of fear on the sunk cost effect. Theoretical implications and practical applications were discussed.
The activity of arylsulfatase A and B on tyrosine O-sulfates

L-Tyrosine O-sulfate was hydrolyzed by pure human arylsulfatase A (arylsufate sulfohydrolase, EC 3.1.6.1). The rate of hydrolysis was 1/20 of the rate with nitrocatechol sulfate, but was comparable to the rate with cerebroside sulfate. The reaction was optimal at pH 5.3--5.5 and displayed zero order kinetics with time and enzyme concentration. The Km was about 35 mM. The enzyme showed no stereospecificity and hydrolyzed D-tyrosine O-sulfate with Km and V similar to those for the L-isomer. Arylsulfatase B was less than 5% as effective as arylsulfatase A in catalyzing the hydrolysis of the tyrosine sulfates. The daily urinary excretion of tyrosine sulfate by a patient with metachromatic leukodystrophy (arylsulfatase A deficiency) was comparable to the excretion by control subjects. The biological relevance of the tyrosine sulfatase activity of arylsulfatase A remains uncertain.
Physical constraints on microbial behavior How you act if you are very small

Physical constraints limit the way in which an organism as small asEscherichia coli can interact with its surroundings. These constraints are listed, together with references to the relevant literature.
Increased Expression of c‐myc Is Associated with Thymoma in Rats Infected with Murine Leukemia Virus A8

Infection of rats with Friend murine leukemia virus (Fr-MLV) clone A8 causes thymoma in all the animals within 7 weeks. The rapid induction of thymoma is associated with a unique enhancer structure in the U3 region of the A8-LTR. Our Southern blot analyses showed that the thymomas were oligo clonal. The A8-induced thymomas showed 3- to 11-fold overexpression of c-myc mRNA. These results suggest that provirus insertion into particular positions of the host genome is correlated with tumorigenesis after A8 infection and that up-regulation of c-myc plays an important role in the induction of thymoma.
Severe acute metabolic acidosis (acute beriberi): an avoidable complication of total parenteral nutrition.

Total parenteral nutrition is one of the most important recent advances in medicine. The delivery of total parenteral nutrition, however, can be associated with a broad spectrum of complications ranging from mechanical (catheter related) to metabolic. We have recently seen a previously unreported complication of total parenteral nutrition - three patients maintained on total parenteral nutrition, who did not receive vitamins and experienced the acute onset of life-threatening metabolic acidosis with pH values as low as 6.70. All responded promptly and completely to the administration of intravenous thiamine, and thus were probably examples of acute beriberi. Acute beriberi is a well-documented syndrome which usually occurs in nutritionally compromised individuals outside the hospital setting who lack thiamine in their diet. Without thiamine, glucose cannot enter the Krebs cycle in order to be completely oxidized for energy production and therefore, accumulates as lactic acid. This lactic acidosis is refra...
Quantitative evaluation of regional differences between epithelia in the adult mouse.

Abstract The composition and proliferation of skin from the ear, tail and footpad and oral mucosa from the palate, cheek and tongue of adult mice were examined. The thickness of the nucleated cell layer of skin snowed an approximately two-fold variation; a similar range was found between that of oral mucosae but that was considerably thicker than skin. No direct correlation between epithelial thickness and the number of nucleated cells was observed. Proliferative activity, assessed following the administration of vinblastine sulphate, and turnover of the epithelium showed a broad range of activities but more rapid in the oral epithelia than in the epidermis, suggesting a relationship between functional stress and proliferative activity. The criteria used clearly distinguish between morphologically different epithelia and should prove useful in examining experimentally produced changes in epithelial histodifferentiation.
The empty set, the singleton, and the ordered pair

For the modern set theorist the empty set O, the singleton {a}, and the ordered pair 〈x, y〉 are at the beginning of the systematic, axiomatic development of set theory, both as a field of mathematics and as a unifying framework for ongoing mathematics. These notions are the simplest building locks in the abstract, generative conception of sets advanced by the initial axiomatization of Ernst Zermelo [1908a] and are quickly assimilated long before the complexities of Power Set, Replacement, and Choice are broached in the formal elaboration of the ‘set of’f {} operation. So it is surprising that, while these notions are unproblematic today, they were once sources of considerable concern and confusion among leading pioneers of mathematical logic like Frege, Russell, Dedekind, and Peano. In the development of modern mathematical logic out of the turbulence of 19th century logic, the emergence of the empty set, the singleton, and the ordered pair as clear and elementary set-theoretic concepts serves as amotif that reflects and illuminates larger and more significant developments in mathematical logic: the shift from the intensional to the extensional viewpoint, the development of type distinctions, the logical vs. the iterative conception of set, and the emergence of various concepts and principles as distinctively set-theoretic rather than purely logical. Here there is a loose analogy with Tarski's recursive definition of truth for formal languages: The mathematical interest lies mainly in the procedure of recursion and the attendant formal semantics in model theory, whereas the philosophical interest lies mainly in the basis of the recursion, truth and meaning at the level of basic predication. Circling back to the beginning, we shall see how central the empty set, the singleton, and the ordered pair were, after all.
Differential absorption lidar CO2 laser system for remote sensing of TATP related gases.

A CW tunable 10.6 μm CO2 laser differential absorption lidar (DIAL) system has been developed, for the first time to our knowledge, for the remote sensing of triacetone triperoxide (TATP) gas vapors, which have strong absorption lines at several wavelengths, including 3.3, 8.3, and 10.6 μm. The DIAL laser beam was transmitted through an enclosed absorption cell containing TATP or SF6, and backscattered returns were measured from a retroreflector array target at ranges of 5-100 m. DIAL sensitivity for the detection of TATP was about 0.5 ng/μl [52 parts in 106(ppm)] for a 0.3 m path.
Psychosocial influences on immunity, including effects on immune maturation and senescence

Studies investigating the influence of psychosocial factors on immunity played a critical and formative role in the field of psychoneuroimmunology (PNI), and have been a major component of articles published in Brain, Behavior and Immunity (BBI). An analysis of papers during the first two decades of BBI from 1987-2006 revealed three behavior-related topics were most prominent: (1) stress-induced changes in immune responses, (2) immune correlates of psychopathology and personality, and (3) behavioral conditioning of immunity. Important subthemes included the effect of early rearing conditions on immune maturation in the developing infant and, subsequently, psychosocial influences affecting the decline of immunity in the senescent host. The responsiveness of cell functioning in the young and elderly helped to validate the view that our immune competence is malleable. Many technical advances in immune methods were also evident. Initially, there was a greater reliance on in vitro proliferative and cytolytic assays, while later studies were more likely to use cell subset enumerations, cytokine quantification, and indices of latent virus reactivation. The reach of PNI extended from the traditional clinical entities of infection, autoimmunity, and cancer to attain a broader relevance to inflammatory physiology, and thus to asthma, cardiovascular and gastrointestinal disease. There continue to be many theoretical and applied ramifications of these seminal findings. Fortunately, the initial controversies about whether psychological processes could really impinge upon and modify immune responses have now receded into the pages of history under the weight of the empirical evidence.
A selectively driven molecular clock

The problem of whether mutations that increase a species' fitness are incorporated into the genome as a function of generation interval or as a function of absolute time is of some interest because of the clock-like nature of amino acid substitutions known to have occurred in the evolution of certain well studied proteins. The molecular clock features a rate of amino acid substitution that is relatively constant when averaged over a sufficiently long time, and the constant rate of substitution is independent of the generation interval of the species involved1,2. Furthermore, the variance in the rate of substitution is roughly twice the mean2. Some authors have argued that the very existence of a molecular clock implies that most amino acid substitutions must be selectively neutral or nearly neutral3. On the other hand, there is no compelling reason to assume that selectively driven gene substitutions would not also exhibit clock-like behaviour, in which case the rate of increase in fitness of a population should be a function of absolute time rather than generation interval. In this report, we have investigated the issue of rate of increase in fitness using initially isogeneic strains of Escherichia coli that had been allowed to evolve independently in glucose-limited chemostats4 for 500 h. The nutrient supply was adjusted in such a manner that some of the strains maintained a doubling time of 2.5 h and others a doubling time of 5.0 h, and the relative fitnesses of the evolving strains were measured periodically. Our main conclusions are that (1) selectively driven gene substitutions detectable as increases in fitness do exhibit clocklike behaviour, (2) when averaged over a sufficiently long time, the rate of increase in fitness is a function of absolute time and independent of generation interval, and (3) except for an initial period related to adjustment to chemostat conditions, the variance in the rate of increase in fitness is very nearly twice the mean.
Segmentation Based on the Healthy-Living Attitude: A Market's Travel Behavior

ABSTRACT Destinations' competitiveness would be enhanced if organizations or destinations could provide appropriate supply components and benefits that suit diverse market segments. Under the circumstance of tourists' unknown attitudes toward the healthy-living component, this study unveils characteristics related to healthy-living market segments and their relating to the tourism system's supply components. Two segments are delineated based on the Healthy-Living Attitudinal Scale and profiled with healthy-oriented destination attributes, sources of information, travel experiences, and general demographics. The main managerial implications that can be derived from this study are the following: (1) cluster one (High Healthy-Living Conscious segment) has more concerns about healthy-oriented destination services and products, (2) special interest (healthy-living) magazines, agencies, and brochures are found to be viable sources of travel information when it comes to establishing a destination's communication...
Effect of Planting and Vine-kill Timing on Sugars, Specific Gravity and Skin Set in Processing Potato Cultivars

Quality and storability of potato tubers harvested for storage are affected by their chemical, physiological and physical maturity. The sucrose concentration in potato tubers is indicative of the chemical maturity of the crop and of the potential processing quality of the crop after storage. High reducing sugar concentrations result in undesirable discoloration of Med potato products. Sucrose does not directly contribute to the discoloration of tuber tissue upon frying, but it influences reducing sugar concentrations during storage. Physiologically mature tubers have maximized their dry matter content, resulting in high specific gravities that are desirable for most aspects of potato processing. We examined the effect of different planting and vine-kill dates on the sucrose and glucose concentrations and specific gravity of five processing potato cultivars grown at Hancock, WI, during 2002 and 2003. Although planting date usually had no effect on sugar content at harvest, sucrose and glucose content decreased with earlier planting date at vine-kill in one of two years. Greater sucrose and glucose concentrations and specific gravities were found at harvest with later vine-kill dates. Of particular concern for processing, stem-end glucose concentrations consistently exceeded bud-end glucose concentrations for all cultivars, regardless of the cultural parameters implemented. Physically immature tubers have poor skin set and are prone to skinning and mechanical damage during harvest, which renders them more vulnerable to dehydration and infection by rotting pathogens in storage. Skin set of ‘Russet Burbank’ tubers in 2003 improved with late vine-kill timing. Our data indicate that chemical maturity does not necessarily correlate with either physiological or physical maturity in processing cultivars, thus rendering the use of cultural practices to improve tuber maturity at harvest problematic.
Morphologies from slippery ballistic deposition model: A bottom-up approach for nanofabrication

(Received 1 October 2010; revised manuscript received 10 February 2011; published 13 May 2011) We report pattern formation using a slippery ballistic deposition (SBD) model where growth germinates from a single site or from sites distributed periodically on a lattice. By changing the sticking probability ps and choosing systems with different lattice constants and symmetries, we demonstrate that a variety of patterns can be generated. These patterns can be further used as scaffolds for nanofabrication. We also demonstrate that by choosing a lateral sticking probability pl at the base that is different than ps, one can control both the early and late time morphologies originating from a seed. Furthermore, we indicate a possible generalization of preparing patterns to higher dimensions that in principle can have potential technological applications for preparing grooves and scaffolds of specific shapes and periodicities.
Common mechanisms of oxidative damage in chronic neurodegenerative conditions: potential points of therapeutic intervention

The number of published research articles and patents addressing neuronal oxidative damage over the past three years makes it impossible to encompass them all in a single article. Therefore, in preparing this review, the decision was made to focus on those reports with the greatest applicability to Alzheimer’s (AD) and Parkinson’s diseases (PD). In addition, emphasis was placed on those patents whose compounds had displayed in vivo efficacy. The three main topics of excitotoxicity, lipid peroxidation and reactive oxygen species (ROS) were selected as having relevance to both AD and PD. Patents pertaining to these diseases were discussed in the context of how they address one or more of these three categories. A trend has emerged over the past three years as research emphasis seems to be shifting away from generic free radical trapping compounds, towards compounds which stimulate the neurone’s endogenous oxidative defences or try to mimic them.
Semianalytical formulation of leaky-mode resonance in periodic elements with asymmetric profiles

The properties of resonant leaky modes at the second stopband are investigated with a semianalytical model applicable to asymmetric-profile gratings. The dispersion properties and guided-mode resonance features are in excellent agreement with exact formulation.
Effects of d-amphetamine, Org 2766, scopolamine, and physostigmine on repeated acquisition of four-response chains in rat

Adult rats were trained to emit a different four-response sequence on three levers for food reinforcement in each daily two-hour session. Four sequences of putatively equal difficulty were used, with each sequence recurring every fourth session. Within-session errors declined as a function of practice. Most subjects showed a significant idiosyncratic sequence bias. d-amphetamine, tested at 0.1–2.0 mg/kg, increased errors as a function of dose. Org 2766 had no effect. Scopolamine and physostigmine, tested at 0.01–1.0 mg/kg, increased errors only at the highest doses, which produced tremor or ataxia. Results were generally consistent with previous results from other species. It was concluded that repeated acquisition in the rat is feasible for behavioral pharmacology and toxicology but that long training times and sequence bias limit its practicality.
Oral Iron Chelators and the Treatment of Iron Overload in Pediatric Patients With Chronic Anemia

Transfusion-dependent hemoglobinopathies, such as thalassemia and sickle cell disease (SCD), represent a major global health burden, with >300000 infants born with SCD or thalassemia annually. Approximately 5% of the world's population are carriers of a potentially pathologic hemoglobin gene.1 In the United States, sickle cell anemia is the most common type of SCD, with a birth prevalence in black individuals of 1 in 375, whereas that of hemoglobin SC disease is 1 in 835, hemoglobin S/β-thalassemia is 1 in 1667, and sickle cell trait is 1 in 12.2 Along with treatment of the underlying disease, chronic anemias are commonly managed by supportive therapy with red blood cell (RBC) transfusions.3,4 Although this is a routine approach in the treatment of thalassemia, transfusions have been less common for patients with other anemias. Recent data, however, have further demonstrated the value of regular transfusions for children with SCD, significantly reducing the risk for primary and secondary stroke, total hospitalizations, vaso-occlusive events, acute chest syndrome, and growth failure.5–7 These data have had a significant impact on clinical practice, prompting widespread recommendations for transcranial Doppler screening in children and transfusion therapy for all high-risk patients. Although the value of RBC transfusions for patients who undergo regular transfusions is increasingly recognized, this approach presents an additional clinical challenge: that of iron overload. Each unit of RBCs contains 200 to 250 mg of iron, and repeated transfusions can rapidly saturate a patient's transferrin; iron overload then develops after 10 to 20 transfusions.8 The accumulation of excess iron leads to the formation of non–transferrin-bound iron (NTBI). This is a toxic component of free (unbound) iron and is associated with progressive organ damage, including liver and heart disease9; children as young as 15 years can develop heart failure. … Address correspondence to Elliott Vichinsky, MD, Children's Hospital and Research Center, Hematology/Oncology Department, 747 52nd St, Oakland, CA 94609. E-mail: evichinsky{at}mail.cho.org
Algorithms for sequential adaptive estimation of prior statistics

When incorrect prior statistics are used to implement sequential filtering algorithms, suboptimum performance and possibly filter divergence results. Thus it is desirable to estimate prior statistics from actual operating records and use these estimates in implementation of the optimum estimation algorithms. This paper presents a survey of currently existing algorithms for the sequential adaptive estimation of prior statistics.
An Achromatic Fourier Processor

An achromatic Fourier processor is presented that is capable of Fourier transforming and imaging spatial frequencies up to 30 lines per millimeter within a 200 nm. spectral bandwidth. A procedure is outlined for optimization using a computer lens design program.
Portability, extensibility and robustness in iROS

The dynamism and heterogeneity in ubicomp environments on both short and long time scales implies that middleware platforms for these environments need to be designed ground up for portability, extensibility and robustness. In this paper, we describe how we met these requirements in iROS, a middleware platform for a class of ubicomp environments, through the use of three guiding principles - economy of mechanism, client simplicity and levels of indirection. Apart from theoretical arguments and experimental results, experience through several deployments with a variety of apps, in most cases not done by the original designers of the system, provides some validation in practice that the design decisions have in fact resulted in the intended portability, extensibility and robustness. A retrospective examination of the system leads the authors to the following lesson: A logically-centralized design and physically-centralized implementation enables the best behavior in terms of extensibility and portability along with ease of administration, and sufficient behavior in terms of scalability and robustness.
Technical metrics for acoustic evaluation

A Technical Metrics Workshop was held at NRL Stennis Space Center, MS, by the NRL Acoustics Division April 29 — May 1, 2008. The primary goal of the workshop was to identify the state-of-the-art technical and scientific metrics for the acoustic and oceanographic research and development communities. A second goal was to relate scientific metrics to engineering and performance metrics, and outline the inclusion of uncertainties in various parameters using metric variability. Participation in the workshop was significant. State-of-the-art technical applications, as well as brief insights into future metrics, requirements for metrics, standards or reference level metrics were presented. This paper briefly summarizes and presents the conclusions of the workshop. This work is a useful reference for building consistent technical metrics within the ocean and acoustic research and development community, as well as providing common guidance for measuring exit and milestone criteria, and for quantifying the contributions of interdisciplinary projects.
An information pipeline model of human-robot interaction

This paper investigates the potential usefulness of viewing the system of human, robot, and environment as an "information pipeline" from environment to user and back again. Information theory provides tools for analyzing and maximizing the information rate of each stage of this pipeline, and could thus encompass several common HRI goals: "situational awareness," which can be seen as maximizing the information content of the human's model of the situation; efficient robotic control, which can be seen as finding a good codebook and high throughput for the Human-Robot channel; and artificial intelligence, which can be assessed by how much it reduces the traffic on all four channels. Analysis of the information content of the four channels suggests that human to robot communication tends to be the bottleneck, suggesting the need for greater onboard intelligence and a command interface that can adapt to the situation.
Introduction to the special issue on the scientific assessment of biomeasures in the Panel Study of Income Dynamics.

This special issue of Biodemography and Social Demography assesses the value to social science and health research of incorporating biomeasures in a social survey. The focus is on the Panel Study of Income Dynamics (PSID), an ongoing, nationally representative panel study of U.S. households. A brief description of the PSID and the features that make it a promising survey for biomeasures is provided along with an overview of each individual article. Seven of the nine articles cover a major health domain: fatness and obesity, metabolic syndrome and cardiovascular disease, infectious disease, inflammation and immune function and cardiovascular disease, daily stress exposure and reactivity, respiratory health, and genetics. These articles describe the scientific rationale for collecting data in each domain as well as the specific biological samples or measurements needed to assess the domain, potential respondent burden, ethical and legal issues, fieldwork logistics, and costs. The final two articles address ...
Evidence Stacks Up That Endothelial Insulin Resistance Is a Culprit in Atherosclerosis

Type 2 diabetes mellitus and the metabolic syndrome greatly increase the risk of cardiovascular disease, manifested as myocardial infarction and stroke. Although it is well known that this risk is largely the result of increased atherosclerosis, the cellular and molecular events within the artery wall responsible for the worsening of atherosclerosis associated with type 2 diabetes mellitus and the metabolic syndrome are less clear. These states are frequently associated with several cardiovascular risk factors, including dyslipidemia, hypertension, obesity, hyperglycemia, and systemic insulin resistance, each of which may contribute to atherosclerosis. Article, see p 418 Insulin resistance in now known to affect the vascular wall itself, in addition to the better-studied insulin target tissues liver, skeletal muscle, and adipose tissue. Vascular endothelial cells, which play critical roles in atherosclerosis by allowing monocytes and other immune cells to enter the atherosclerotic lesion and by producing proatherogenic and antiatherogenic molecules, develop insulin resistance in both humans and mice concomitant with dyslipidemia and systemic insulin resistance.1 Endothelial cells can also contribute to systemic insulin resistance.2 Insulin has important biological effects in endothelial cells that affect atherosclerosis. Activation of the insulin receptor results in tyrosine phosphorylation of insulin receptor substrate 1 and 2 and subsequent activation of phosphoinositide 3-kinase (PI3K) and the serine/threonine protein kinase Akt. Akt has several targets in endothelial cells, one of which is endothelial nitric oxide (NO) synthase (eNOS). Insulin-induced activation of the PI3K-Akt-eNOS pathway causes increased production of NO, vasorelaxation,3 and suppressed expression of vascular cell adhesion molecule-1, an important adhesion molecule used by monocytes to invade the vessel wall. These actions of insulin are likely to be antiatherosclerotic (Figure) because both vascular cell adhesion molecule-1–deficient mice and eNOS-deficient mice exhibit reduced atherosclerosis4,5 (although …
Lexical Differences in Autobiographical Narratives from Schizophrenic Patients and Healthy Controls

We present a system for automatic identification of schizophrenic patients and healthy controls based on narratives the subjects recounted about emotional experiences in their own life. The focus of the study is to identify the lexical features that distinguish the two populations. We report the results of feature selection experiments that demonstrate that the classifier can achieve accuracy on patient level prediction as high as 76.9% with only a small set of features. We provide an in-depth discussion of the lexical features that distinguish the two groups and the unexpected relationship between emotion types of the narratives and the accuracy of patient status prediction.
B-type natriuretic peptide serum levels in acute heart failure: Reply

Our review1 summarises the evidence of the clinical role of plasma BNP measurements in the management of patients in a variety of clinical settings and situations. As is clearly stated in the paper, and as all experienced physicians will know, BNP should not be used as a `stand alone' test but should be interpreted in the clinical context. Nevertheless, the results of studies published to date (and further studies currently reporting at scientific meetings but not yet published in full) support the diagnostic utility of BNP measurement, particularly in …
Caveolin-3 knock-out mice develop a progressive cardiomyopathy and show hyperactivation of the p42/44 MAPK cascade

A growing body of evidence suggests that muscle cell caveolae may function as specialized membrane micro-domains in which the dystrophin-glycoprotein complex and cellular signaling molecules reside. Caveolin-3 (Cav-3) is the only caveolin family member expressed in striated muscle cell types (cardiac and skeletal). Interestingly, skeletal muscle fibers from Cav-3 (−/−) knock-out mice show a number of myopathic changes, consistent with a mild-to-moderate muscular dystrophy phenotype. However, it remains unknown whether a loss of Cav-3 affects the phenotypic behavior cardiac myocytes in vivo. Here, we present a detailed characterization of the hearts of Cav-3 knock-out mice. We show that these mice develop a progressive cardiomyopathic phenotype. At four months of age, Cav-3 knock-out hearts display significant hypertrophy, dilation, and reduced fractional shortening, as revealed by gated cardiac MRI and transthoracic echocardiography. Histological analysis reveals marked cardiac myocyte hypertrophy, with accompanying cellular infiltrates and progressive interstitial/peri-vascular fibrosis. Interestingly, loss of Cav-3 expression in the heart does not change the expression or the membrane association of the dystrophin-glycoprotein (DG) complex. However, a marker of the DG complex, α-sarcoglycan, was specifically excluded from lipid raft domains in the absence of Cav-3. Because activation of the Ras-p42/44 MAPK pathway in cardiac myocytes can drive cardiac hypertrophy, we next assessed the activation state of this pathway using a phospho-specific antibody probe. We show that p42/44 MAPK (ERK1/2) is hyperactivated in hearts derived from Cav-3 knock-out mice. These results are consistent with previous in vitro data demonstrating that caveolins may function as negative regulators of the p42/44 MAPK cascade. Taken together, our data argue that loss of Cav-3 expression is sufficient to induce a molecular program leading to cardiac myocyte hypertrophy and cardiomyopathy.
Lactose and maltose uptake by Streptococcus lactis.

Abstract Resting cells of Streptococcus lactis 7962 were examined for rate of uptake of radioactive lactose following growth of the cells in broth media containing lactose, maltose, glucose, or glucose plus lactose as carbon sources. Lactose-grown cells accumulated label at the fastest rate, followed in order by cells grown on maltose, lactose plus glucose, or glucose. The uptake of radioactive maltose and methyl- β-D -thiogalactopyranoside (TMG) also was examined following growth of the cells in broth containing maltose or lactose. Labeled TMG was not taken up at an appreciable rate, especially by the maltose-grown cells; radioactive maltose, however, was accumulated rapidly by maltose-grown cells, but only at a very low rate by lactose-grown cells. These data indicated that specific permeases and metabolic enzymes were induced by lactose and maltose in S. lactis 7962. Inhibition of substrate uptake by glucose indicated that synthesis of these enzyme systems was controlled by catabolite repression.
A prototypical cytidylyltransferase: CTP:glycerol-3-phosphate cytidylyltransferase from Bacillus subtilis

Background: The formation of critical intermediates in the biosynthesis of lipids and complex carbohydrates is carried out by cytidylyltransferases, which utilize CTP to form activated CDP-alcohols or CMP-acid sugars plus inorganic pyrophosphate. Several cytidylyltransferases are related and constitute a conserved family of enzymes. The eukaryotic members of the family are complex enzymes with multiple regulatory regions or repeated catalytic domains, whereas the bacterial enzyme, CTP:glycerol-3-phosphate cytidylyltransferase (GCT), contains only the catalytic domain. Thus, GCT provides an excellent model for the study of catalysis by the eukaryotic cytidylyltransferases. Results: The crystal structure of GCT from Bacillus subtilis has been determined by multiwavelength anomalous diffraction using a mercury derivative and refined to 2.0 A resolution (R factor 0.196; R free 0.255). GCT is a homodimer; each monomer comprises an α/β fold with a central 3-2-1-4-5 parallel β sheet. Additional helices and loops extending from the α/β core form a bowl that binds substrates. CTP, bound at each active site of the homodimer, interacts with the conserved 14HXGH and 113RTXGISTT motifs. The dimer interface incorporates part of a third motif, 63 RYVDEVI, and includes hydrophobic residues adjoining the HXGH sequence. Conclusions: Structure superpositions relate GCT to the catalytic domains from class I aminoacyl-tRNA synthetases, and thus expand the tRNA synthetase family of folds to include the catalytic domains of the family of cytidylyltransferases. GCT and aminoacyl-tRNA synthetases catalyze analogous reactions, bind nucleotides in similar U-shaped conformations, and depend on histidines from analogous HXGH motifs for activity. The structural and other similarities support proposals that GCT, like the synthetases, catalyzes nucleotidyl transfer by stabilizing a pentavalent transition state at the α-phosphate of CTP.