cssi/SciSciGPT-SciSciNet huggingface dataset:
Mössbauer Study of the MoFe Protein of Nitrogenase from Azotobacter vinelandii Using Selective 57Fe Enrichment of the M-Centers

The molybdenum−iron (MoFe) protein of nitrogenase contains two unique metalloclusters called P-cluster [8Fe-7S] and M-center (FeMo cofactor, [7Fe-9S-Mo-homocitrate]). Using samples containing M-centers selectively enriched with 57Fe (57M56P), we have studied three M-center states with Mossbauer spectroscopy. The results are as follows. A detailed analysis of the Mossbauer spectra of the S = 3/2 state MN recorded in applied fields up to 8.0 T has revealed the features of the seventh Fe site which had eluded previous Mossbauer and ENDOR studies. This site has unusually small and anisotropic magnetic hyperfine interactions (Aiso ≈ −4 MHz). Our studies have also revealed that the spectroscopic component previously labeled B1 represents two equivalent Fe sites. Six of the M-center irons are trigonally coordinated to bridging sulfides; their unusual isomer shifts are discussed with particular reference to a trigonally coordinated Fe(II) thiolate complex synthesized by Power and co-workers (Inorg. Chem. 1995, 34...
Sex-influenced association of nonalcoholic fatty liver disease with coronary heart disease

Objective This study investigated whether nonalcoholic fatty liver disease (NAFLD) predicts prevalent coronary heart disease (CHD).
Darwin after Malthus.

In the Origin of Species (1859) natural selection is presented as an autonomous biological process which is, potentially, in continuous operation. No organism is perfect. There is always room for improvement. At any time or place a species, however well adapted it may seem to be, may give rise to still better-adapted forms. New variations may appear that are better suited for existing conditions, and when this happens the pressure of population will work to select them and their similarly favored offspring until a new, improved form is created. Natural selection, Darwin said in the Origin, is "daily and hourly scrutinising, throughout the world, every variation"; it is "silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life." I In the "Essay of 1844," on the other hand, selection is depicted as confined and limited in its operation. Compare the statement I have just quoted with this description of the evolutionary process from the "Essay": if there are variation and struggle in nature, then "new races of beings will, perhaps only rarely, and only in some few districts, be formed."2 One's first reaction is probably to dismiss this contrast by saying that in 1844 Darwin was less confident or merely more cautious in his exposition. But there is much more to it than this. In 1844 natural selection was limited by what I would like to call structural constraints, which were eliminated sometime before 1859. By structural constraints I mean those imposed by the framework of beliefs about nature within which Darwin supposed that his evolutionary mechanism operated. To be more precise, Darwin in 1844 still believed in perfect adaptation. Perfectly adapted forms are not capable of further improvement. They vary little; so, among them, natural selection has little material on
Perceptions of reproductive risk and carrier testing among adolescent sisters of males with chronic granulomatous disease.

Although recent research has investigated the attitudes of parents, professionals, and adult siblings toward carrier testing of minors, no studies have focused on the experiences of minor siblings of individuals with X-linked and autosomal recessive conditions. To explore adolescent sisters' perceptions of their reproductive risks, attitudes toward carrier testing, and resources for information and support, we interviewed 14 parents and 9 sisters (ages 12-15) of males with chronic granulomatous disease (CGD), a primary immunodeficiency disorder inherited in both an X-linked recessive and autosomal recessive fashion. Our semistructured telephone interviews were audiotaped, transcribed, and subjected to template analysis (a common qualitative methodology). Girls were all aware that CGD is an inherited condition and each had made an assessment of her reproductive risk. All girls considered their parents to be their best source of information and support, but girls had trouble initiating discussions for fear of upsetting their parents. All girls and parents considered eventual carrier testing vital for reproductive decision-making and relationship-building. However, girls favored carrier testing at a later age and expressed more concerns about psychological risks associated with testing than did their parents. When faced with the hypothetical situation of being offered carrier testing tomorrow, half of the parents and untested daughters disagreed on the desirability of the test, with parents more likely to favor testing. Including adolescent sisters in family-based genetic counseling that provides an opportunity for age-appropriate discussion of inheritance and the timing, risks, and benefits of carrier testing would be beneficial to them.
Fracture in Titanium Diboride

Transmission electron microscopy is used to examine the structure of shock-loaded titanium diboride. At a shock pressure of 1.7 GPa, fracture occurs by the nucleation and splitting of b = [001] dislocation loops in the basal plane. The tensile stress of the shock pulse opens the dislocation loops into microcracks. The dislocation loops form when point defects spontaneously condense at impurities. Dislocation loops are also left by moving dislocations in a deformation band and nucleate at pressure boundaries. Transmissionselektronenmikroskopie wird benutzt, um die Struktur von Schock-belastetem Titandiborid zu untersuchen. Bei einem Schock-Druck von 1,7 GPa tritt Bruch auf durch Bildung und Aufspaltung von b = [001]-Versetzungsschleifen in der Basisebene. Die Dehnungsspannungen der Schockimpulse offnen die Versetzungsschleifen in Mikrorisse. Die Versetzungsschleifen bilden sich, wenn die Punktdefekte spontan an Storstellen kondensieren. Versetzungsschleifen werden auch von wandernden Versetzungen in einem Deformationsband zuruckgelassen und bilden sich an Druckgrenzen.
Effects of subarachnoid hemorrhage on platelet-derived vasoconstriction of rabbit basilar artery

Abstract The effects of subarachnoid hemorrhage on platelet-derived vasoconstriction of the isolated rabbit basilar artery were examined using an isometric tension recording method. The subarachnoid hemorrhage was induced by injecting arterial blood in the cisterna magna. The following points were confirmed: (1) the maximal contraction produced by the platelets (10 7 /mL) treated with indomethacin or dazoxiben (thromboxane synthetase inhibitor) were suppressed (65% or 70% of the control); (2) the contraction of the arteries treated with ONO-3708 (thromboxane A 2 antagonist) or ketanserin was inhibited (73% or 8.4%), as was contraction after subarachnoid hemorrhage (67% or 14%); (3) platelet-induced contraction was potentiated after subarachnoid hemorrhage; and (4) serotonin-induced contraction was potentiated after subarachnoid hemorrhage. However, synthetic thromboxane A 2 -induced contraction was not potentiated. The present experiments suggest that both serotonin and thromboxane A 2 contribute to vasoconstrictions induced by the platelets, before and after subarachnoid hemorrhage. The platelet-derived contraction response is potentiated after subarachnoid hemorrhage and serotonin is responsible for the increased reactivity.
Mammalian Neutral Sphingomyelinases: Regulation and Roles in Cell Signaling Responses

Ceramide, a bioactive lipid, has been extensively studied and identified as an essential bioactive molecule in mediating cellular signaling pathways. Sphingomyelinase (SMase), (EC 3.1.4.12) catalyzes the cleavage of the phosphodiester bond in sphingomyelin (SM) to form ceramide and phosphocholine. In mammals, three Mg2+-dependent neutral SMases termed nSMase1, nSMase2 and nSMase3 have been identified. Among the three enzymes, nSMase2 is the most studied and has been implicated in multiple physiological responses including cell growth arrest, apoptosis, development and inflammation. In this review, we summarize recent findings for the cloned nSMases and discuss the insights for their roles in regulation ceramide metabolism and cellular signaling pathway.
Dependence of the insulator-metal transition in EuO on magnetic order

Abstract The Hall coefficient in an EuO sample which exhibited an isulator-metal transition was measured at T ≈ 4Tc in fields up to 150 kOe. The results indicate that the activation energy does not vary linearly with magnetization, contrary to the conclusion of Penney et al.
Utilization and predicted trends of behavioral inventories

Published articles (N=1703) during the period 1975 to 1982 in three behavioral journals (Behavior Therapy, Journal of Behavior Therapy and Experimental Psychiatry, andJournal of Applied Behavior Analysis) were reviewed for the utilization of preintervention and categories of behavioral inventories. Results revealed that (a) the three forms of the Fear Survey Schedule (FSS) and the Social Avoidance and Distress Scale (SADS) were the most utilized traditional behavioral measures, (b) new self-developed inventories were reported with significantly (p<.05) different frequencies across the three journals, (c) numerous published inventories beyond the traditional FSS and SADS were reported, and (d) an expanded use of IQ measures in preintervention behavioral assessment was also found. Trends regarding the nature of behavioral inventories among the three journals and a discussion on advances in behavioral assessments are presented.
The twisted tale of saturated fat

Summary Recent research results mandate a careful re-evaluation of the widespread belief that dietary saturated fat is harmful. Specifically, multiple recent reports find no association between dietary saturated fat intakes and cardiovascular disease (CVD). There is, however, a consistent pattern of increased risk for both CVD and type-2 diabetes associated with increased levels of saturated fatty acids (SFA) in circulating lipids. This raises the important question as to what contributes to increased levels of saturated fat in the blood? Whereas dietary intake of saturated fats and serum levels of SFA show virtually no correlation, an increased intake of carbohydrate is associated with higher levels of circulating SFA. This leads to the paradoxical conclusion that dietary saturated fat is not the problem; rather it’s the over-consumption of carbohydrate relative to the individual’s ability to metabolize glucose without resorting to de novo lipogenesis. From this perspective, insulin resistant states like metabolic syndrome and type-2 diabetes can be viewed as carbohydrate intolerance, in which a high carbohydrate intake translates to increased serum SFA and therefore increased risk. Dietary saturated fat recommendations and unintended consequences A reduction in the consumption of dietary saturated fat (SFA) has been the focus of nutritional recommendations for decades in the United States and many other countries. The fundamental justification for this dietary recommendation is the diet heart hypothesis. This hypothesis holds that dietary SFA, on average, increases circulating levels of low density lipoprotein cholesterol (LDL-C), which in turn increases cardiovascular risk. In the four decades since the diet heart hypothesis was proposed, it has not been proven. In fact, repeated studies involving the restriction of dietary SFA have failed to decrease risk of heart disease, suggesting (if not proving) that this paradigm has inherent flaws. According to dietary trends over the past few decades, Americans have actually decreased their consumption of SFA; but at the same time they have replaced those calories with an even greater amount of carbohydrate. Thus our current epidemics of obesity and diabetes have occurred during a time when the population has increased their consumption of carbohydrate, not SFA. A recent meta-analysis showed that this dietary manipulation – switching saturated fat by carbohydrate – significantly increased risk of coronary events [1]. By continuing to promote lower intake of saturated fat, if even more people replace those calories with carbohydrate, this misbegotten campaign to decrease dietary SFA could have the unintended effect of accelerating coronary disease rates.
Target tracking on an unstabilized imaging platform

This paper describes the measuring and modeling of jitter effects for a manportable missile system. We present a tracking approach which reduces sensitivity to jitter induced image degradations. The tracking approach described consists of small and large target tracking algorithms. The small target algorithm reduces interlace effects by extracting target features which are relatively insensitive to interlace errors. Adaptive threshold selection and target feature extraction will be described. A sparse correlation large target tracking algorithm will also be described.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Roller nanoimprint lithography

An alternative approach to flat nanoimprint lithography (NIL)—roller nanoimprint lithography (RNIL) is demonstrated. Compared with flat NIL, RNIL has the advantage of better uniformity, less force, and the ability to repeat a mask continuously on a large substrate. Two methods for RNIL are developed: (a) rolling a cylinder mold on a flat, solid substrate; (b) putting a flat mold directly on a substrate and rolling a smooth roller on top of the mold. Using our current roller nanoimprint system, sub-100 nm resolution pattern transfer has been achieved.
Risk factors in siblings of people with premature coronary heart disease

Prior studies of the contribution of coronary disease risk factors to familial aggregation of premature coronary disease may have underestimated risk factors by relying on self-reported risk factor prevalence levels or, when risk factors have been measured, by using cut points in excess of the 90th percentile. To determine the actual prevalence of hyperlipidemia, hypertension and diabetes, and the awareness of these coronary risk factors in unaffected family members, 150 apparently coronary disease-free siblings of 86 people who had documented coronary disease before 60 years of age were studied. All subjects participated in a 1 day screening preceded by a self-administered risk factor questionnaire and a personal interview. Participation of both the index patients and siblings exceeded 86%. With the use of nationally established recommendations for blood pressure and lipids, which are based on coronary disease risk curves, screening revealed that 48% of brothers and 41% of sisters were hypertensive, 45% of brothers and 22% of sisters had a lipid abnormality, 38% of siblings were current cigarette smokers and 4.7% were diabetic. Two or more risk factors were present in 42% of brothers and 26% of sisters. More than 75% of siblings had one or more risk factors that would require intervention. When compared with a race-, gender- and age-matched reference population from the Lipid Research Clinics Prevalence Study, distributions for blood pressure and for total and low density lipoprotein cholesterol were higher for the siblings in every gender and age group.(ABSTRACT TRUNCATED AT 250 WORDS)
The Kuramoto-Sivashinsky equation: a bridge between PDE's and dynamical systems

Abstract Through extensive numerical simulation, we have characterized the transition to chaos of the solutions to the Kuramoto-Sivashinsky equation. The attracting solution manifolds undergo a complex bifurcation sequence including multimodal fixed points, invariant tori, traveling wave trains, and homoclinic orbits. We relate this behavior to earlier work where the Kuramoto-Sivashinsky equation was shown to behave as a finite dimensional dynamical system of ordinary differential equations.
Effect of Temperature and Cold Work on the Crack Growth Rate of Alloy 600 in Primary Water

Abstract The susceptibility of alloy 600 (UNS N06600) to stress corrosion cracking (SCC) in hydrogenated high-temperature water was studied as a function of the degree of cold work (CW) of the allo...
Carbon monoxide donors or heme oxygenase-1 (HO-1) overexpression blocks interleukin-18-mediated NF-κB–PTEN-dependent human cardiac endothelial cell death ☆

The objective of this study was to determine whether heme oxygenase-1 (HO-1) or heme metabolites exert cytoprotective effects on interleukin-18-mediated endothelial cell (EC) death. Treatment with interleukin (IL)-18 increased NF-kappaB activation and PTEN induction, suppressed Akt activation, and stimulated EC death. While ectopic expression of p65 enhanced PTEN transcription, adenoviral transduction of dnIkappaB-alpha, dnp65, or dnIKKbeta was inhibitory. Furthermore, IL-18 suppressed HO-1 mRNA expression via enhanced mRNA degradation. Overexpression of HO-1, treatment with HO-1 inducer hemin, or the CO donor cobalt (III) protoporphyrin IX all reversed IL-18-mediated NF-kappaB activation, PTEN induction, Akt suppression, and EC death. Furthermore, hemin induced HO-1 expression, and HO-1 knockdown, HO-1 inhibition, or CO scavengers all reversed the prosurvival effects of hemin. In addition, the CO donors CORM-1 and CORM-3 and the heme metabolites biliverdin and bilirubin attenuated IL-18-induced EC death via a similar signaling pathway. IL-18 induced p38alpha MAPK activation, and suppressed p38beta isoform expression. While p38alpha knockdown attenuated, p38beta knockdown potentiated IL-18-mediated EC death. Hemin and HO-1 reversed IL-18-mediated p38alpha induction and restored p38beta levels. These results demonstrate that IL-18 suppresses HO-1 expression and induces EC death. HO-1 overexpression, HO-1 induction, or treatment with heme metabolites all reverse IL-18-mediated p38alpha MAPK and NF-kappaB activation, PTEN induction, Akt suppression, and EC death. Thus, HO-1 inducers and CO donors may have the therapeutic potential to effectively block IL-18 signaling and reduce IL-18-dependent vascular injury and inflammation.
The platelet reactivity of vascular graft prostheses: an in vitro model to test the effect of preclotting.

Abstract An in vitro perfusion system was used to study the platelet reactivity of the following vascular graft materials when tested with human blood: expanded polytetrafluoroethylene (ePTFE), crimped Dacron Bionit (DB) and preclotted Dacron Bionit (DB/PC). These materials were simultaneously compared to silicone rubber (SR) using an identical perfusion circuit with the same donor's blood. All vascular graft materials tested in this in vitro perfusion system caused some degree of platelet activation as shown by a decrease in platelet count, an increase in platelet factor 3 activity, elevation of plasma levels of both platelet factor 4 and β-thromboglobulin and decreased platelet aggregability. The observed platelet activation was striking for Dacron and especially preclotted Dacron, with ePTFE showing low levels of platelet activation. Platelet activation fay Dacron was initially rapid and then levelled off, whereas the platelet activation with preclotted Dacron began more slowly, but reached much greater levels after three hours of in vitro perfusion.
Further Tests of an Abbreviated Vigilance Task: Effects of Signal Salience and Jet Aircraft Noise on Performance and Stress

The effects of signal salience and jet-aircraft noise on performance and self-reports of stress were examined in an abbreviated vigilance task (12 min) that duplicates many of the findings with longer duration vigilance tasks (Temple et al., 2000). As is the case with longer vigils, signal detection in the abbreviated task was poorer for low salience than for high salience signals and stress scores, as indexed by the Dundee Stress State Questionnaire (Matthews, Joiner, Gilliland, Campbell, & Falconer, 1999), were generally greater when observers were required to detect low as compared to high salience signals. Unlike longer vigils, however, signal detection in the abbreviated task was superior in the presence of noise than in quiet, and noise generally attenuated self-reports of stress. The beneficial effect of jet-aircraft noise for the abbreviated task differentiates it from longer vigilance tasks and suggests that noise may have short-term positive value in vigilance.
Mechanical Properties of a Complete Microtubule Revealed through Molecular Dynamics Simulation

Microtubules (MTs) are the largest type of cellular filament, essential in processes ranging from mitosis and meiosis to flagellar motility. Many of the processes depend critically on the mechanical properties of the MT, but the elastic moduli, notably the Young's modulus, are not directly revealed in experiment, which instead measures either flexural rigidity or response to radial deformation. Molecular dynamics (MD) is a method that allows the mechanical properties of single biomolecules to be investigated through computation. Typically, MD requires an atomic resolution structure of the molecule, which is unavailable for many systems, including MTs. By combining structural information from cryo-electron microscopy and electron crystallography, we have constructed an all-atom model of a complete MT and used MD to determine its mechanical properties. The simulations revealed nonlinear axial stress-strain behavior featuring a pronounced softening under extension, a possible plastic deformation transition under radial compression, and a distinct asymmetry in response to the two senses of twist. This work demonstrates the possibility of combining different levels of structural information to produce all-atom models suitable for quantitative MD simulations, which extends the range of systems amenable to the MD method and should enable exciting advances in our microscopic knowledge of biology.
Coherent Measurements with Fiber-Laser Frequency Combs

The coherent and broad spectral output of fiber-laser frequency combs can be exploited for a variety of high-resolution measurements outside of conventional frequency metrology. We will discuss recent measurements in spectroscopy, ranging, and telecommunication components.
Regional polarimetric quantitative precipitation estimation over the Pigeon River Basin

Quantitative precipitation estimation (QPE) from radar measurements remains a principal objective for weather researchers and forecasters. The objective of this paper is to present the development of a regional dual polarization QPE process known as the RAdar Multi-Sensor QPE (RAMS QPE). This scheme applies the dual polarization radar rain rate estimation algorithms developed at Colorado State University into an adaptable QPE system. The methodologies to combine individual radar scans, and then merge them into a mosaic are described. The implementation and evaluation is performed over a domain that occurs near the Pigeon River Basin near Asheville, NC. In this mountainous locale, beam blockage, beam overshooting, orographic enhancement, and the unique climactic conditions complicate the development of reliable QPE's from radar. The QPE precipitation fields evaluated in this analysis will stem from the dual polarization radar data obtained from the local NWS WSR-88DP radars as well as the NASA NPOL research radar.
Who Let the Dogs In? A Pets Policy for a Supported Housing Organization

This article examines the role of pets for individuals with psychiatric disorders who live in supported housing. Using a case study approach, we describe the process of consultation with an integrated, supported housing organization during the assessment, development, and implementation of a policy to allow tenants to keep pets in their apartments. Themes from interviews with adults with psychiatric disabilities who kept pets suggest that pets provide a sense of connectedness, responsibility, and emotional stability. Employees of the organization had differential views about the advisability of people with mental illness keeping pets in their apartments. Implications of our experiences for the promotion of pet ownership for people with psychiatric disorders are discussed.
The Relationship of Low-Level Winds and Moisture to Convection in the Tropical Pacific

Abstract Strong convection in the tropical Pacific is found to be enhanced when low-level winds are westerly and poleward directed. This means that winds which blow opposite to the normal easterly, equatorward trade-wind flow are associated with strong convection. Linear regression demonstrates that about 30%–40% of the variance in conviction across the Pacific during the 1982–83 El Nino can be explained by low-level precipitable water plus the low-level winds.
The Challenge of Pediatric AIDS A Framework for Early Childhood Special Education

Providing early childhood special education services to children with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) is a challenge. This challenge requires flexibility and an awareness of best-practice recommendations for children with disabilities and special health care needs. This article provides a framework for early childhood special educators as they develop and implement service systems for this growing population of children.
Vascular endothelial growth factor expression in the endometrium during the menstrual cycle, implantation window and early pregnancy.

Purpose of review The review aims to summarize recent data about vascular endothelial growth factor and its implications in the normal endometrium during the menstrual cycle, implantation window and early pregnancy. Recent findings Angiogenesis is crucial for the development of endometrium as well as for embryo implantation and establishment of pregnancy. A number of cytokines and growth factors including vascular endothelial growth factor are known to modulate angiogenesis in human endometrium in vitro and in vivo. Intrauterine vascular endothelial growth factor expression has been shown to be regulated in a cycle-dependent fashion. Recent studies have demonstrated that female sex steroid hormones and gonadotrophins contribute to the regulation of vascular endothelial growth factor by endometrial glandular epithelial and stromal cells. Vascular endothelial growth factor levels increase around the peri-implantation period and in the late secretory and pre-menstrual phases. Further, the production of this angiogenic growth factor appears to be related to decidualization. Summary Vascular endothelial growth factor is a key regulator of angiogenesis and vascular function in the human endometrium. Aberrant endometrial angiogenesis may result in menstrual dysfunction, failed implantation and first-trimester miscarriage. The possibility of enhancing or inhibiting angiogenic activity in the endometrium will provide a novel approach to the manipulation of reproductive functions.
An Instrument to Measure Visual Discrimination in Young Children

confounding of motor coordination was administered to 291 3-, 4-, and 5-yr.old Negro and Caucasian boys and girls from 2 levels of socioeconomic starus. Significant age and race main effects were found but there were no reliable differences for sex or SES. A major and critical problem in most studies of perceptual discrimination - in young children is the inadeq~~acy of criteria or instruments for measuring this ability. The most commonly used tests are Bender (1938), also Koppitz ( 1964), Frostig ( 1964), and Winterhaven ( 1966). All of these, however, confound eye-hand coordination with perceptual discrimination skill. A new test developed by Rosenberg (1966) avoids this criticism by employing a pointing or selection response, but there is no attempt to get at different types of discrimination tasks. With young children, the test most frequently used for the assessment of visual discrimination is the Frostig Developmental Test of Visual Perception. It presents paper-and-pencil rasks covering five areas: eye-hand coordination, figure-ground, form-constancy, position-in-space, and spatial relationships. However, for very young children, especially those from disadvantaged homes, where opportunities to use paper-and-pencil are exceedingly limited, instruments of this type do not seem to be appropriate. In a preliminary study carried out by the present authors, using both the Winterhaven and the Frostig tests with a group of 17 4-yr.-old children, it was found that: ( 1) The language in which the tasks were presented tended to confuse rather than instruct. (2) The test took, on the average, about 40 min. to administer and most of the children lost interest about half way through. (3) The use of different colors for marking was not only conf~~sing but also served to distract children from the task since there was a general tendency to use the colors in drawing pictures. If there is any validity to the hypothesis chat visual discrimination skills are important prerequisites to beginning reading, there is need for a method of measuring this skill without the confounding variables of motor skill, task comprehension, and experience with paper-and-pencil activities. The present paper is a report of the construction of one such instrument, as a first step in a more comprehensive sn~dy of variables affecting children's ability to learn to read. METHOD
Ground-state properties of LiV2O4 and Li1-xZnx(V1-yTiy)2O4

We present susceptibility, microwave resistivity, NMR and heat-capacity results for Li1-xZnx(V1-yTiy)2O4 with 0 ? x ? 0.3 and 0 ? y ? 0.3. For all doping levels the susceptibility curves can be fitted with a Curie-Weiss law. The paramagnetic Curie-Weiss temperatures remain negative with an average value close to that of the pure compound Θ≈ - 36 K. Spin-glass anomalies are observed in the susceptibility, heat-capacity and NMR measurements for both type of dopants. From the temperature dependence of the spin-lattice relaxation rate we found critical-dynamic behavior in the Zn doped compounds at the freezing temperatures. For the Ti-doped samples two successive freezing transitions into disordered low-temperature states can be detected. The temperature dependence of the heat capacity for Zn-doped compounds does not resemble that of canonical spin glasses and only a small fraction of the total vanadium entropy is frozen at the spin-glass transitions. For pure LiV2O4 the spin-glass transition is completely suppressed. The temperature dependence of the heat capacity for LiV2O4 can be described using a nuclear Schottky contribution and the non-Fermi liquid model, appropriate for a system close to a spin-glass quantum critical point. Finally an ( x / y , T )-phase diagram for the low-doping regime is presented.
Neuropeptide Y: a powerful modulator of epithelial ion transport.

Abstract Neuropeptide Y (NPY) is a major gut peptide localized in the intestinal mucosa of several mammalian species. Ileal mucosa from rabbit and guinea-pig was mounted in Ussing chambers in order to study the effect of NPY on short circuit current. Neuropeptide Y inhibited the short circuit current when applied to the serosal side of the tissue. The maximum change in short circuit current was -50 +/- 6 microA cm-2 in the rabbit ileum and -49 +/- 14 microA cm-2 in the guinea-pig ileum. The EC50 was 3 X 10(-8) M in both species. Pretreatment of rabbit ileum with the alpha 2-adrenoceptor antagonist, yohimbine (1 X 10(-6) M) for 10 min did not reduce the response of the tissue to neuropeptide Y (1 X 10(-7) M). When applied serosally to rabbit ileal mucosa, the related peptide YY caused a maximum change in short circuit current of -60 +/- 13 microA cm-2; the EC50 was 2 X 10(-9) M. Isotopic flux studies in rabbit ileum showed that 1 X 10(-7) M neuropeptide Y enhanced mucosal-to-serosal Na+ and Cl- fluxes and reduced serosal-to-mucosal Cl- flux. Replacement of chloride with gluconate on both sides of the tissue significantly reduced the change in short circuit current produced by neuropeptide Y (1 X 10(-7) M), as did a similar replacement of bicarbonate. It is concluded that neuropeptide Y and peptide YY are the most potent neurotransmitters or hormones so far described in their ability to attenuate electrogenic transport in the small intestine.
The Conjectured Highest Scoring Machines for Rado's Σ(k) for the Value k = 4

A study of the output of a heuristic computer program reveals two four-state binary Turing machines which yield the highest known score for four states in Rado's co-called "Busy Beaver" logical game. There is evidence which supports the conjecture that this score of 13 is the particular value of Σ(4), where Σ is a noncomputable integer function associated with this game. It is also conjectured that S(4) = 106, where S is another noncomputable function, the maximum shift number, of interest in Rado's study. Complete solution of the problem for four states has been reduced to a relatively small set of machines.
The locus elav of Drosophila melanogaster is expressed in neurons at all developmental stages

The locus elav (ella-vee) of Drosophila melanogaster, which is necessary for the proper development of the embryonic and adult nervous systems, has been characterized both genetically and molecularly. This locus has been shown to be transcribed exclusively within, and ubiquitously throughout, the developing nervous system during Hours 6 to 12 of embryogenesis. We present in situ RNA localization data which demonstrate that elav is expressed in the central nervous system as well as the peripheral nervous system of embryos, larvae, pupae, and adults. We also demonstrate that elav is not transcribed in embryonic or larval neuroblasts (the neuronal progenitor cells), or in at least one type of glial cell. These data provide evidence that the requirement for elav function is not limited to the 6- to 12-hr embryonic nervous system and the adult eye and developing optic lobe, but that its function is required for the development and continued maintenance of all neurons of the organism.
The volume change of migration of the stage I self-interstitial atom in ion-irradiated tungsten

Abstract A detailed study has been performed of the effect of the electric field (∼4.75 VA−1) required for field ionization of helium gas atoms, in the field ion microscope (FIM), on the isochronal recovery spectrum of ion (30 keV W+) irradiated tungsten. All the irradiations were performed in-situ under ultra-high vacuum conditions (<10−9 torr) to a constant dose of 5 · 1012 ion cm−2. The FIM specimens used were prepared from oriented single crystals of high purity tungsten with a resistivity ratio of 5 · 104. The experimental procedure involved a comparison of the isochronal recovery spectra in the range 18 to 120 K of specimens irradiated at 18 K in the absence of both the electric field and the imaging gas with identical specimens which were irradiated at 50 K and then cooled to 18 K in the absence of both the electric field and the imaging gas. The results of these recovery experiments demonstrated that the field of ∼4.75 VA−1 has only a minimal effect on the annealing kinetics of self-interstitial a...
Function Keys to the Rescue

We have 15 OCLC terminals, 4 of which are used exclusively for cataloging and are connected to a CLSI interface and a printer used for labels. The four cataloging terminals are M300 Workstations; one was recently replaced with an XT. After acquiring an Epson printer in the fall of 1986, we found to our dismay that the sl6 labels we'd been using since 1975 wouldn't print correctly with this configuration. Specifically, our sl6 screen has one too many lines, so the last line prints off the bottom of one label and on to the next. This was, and still is, puzzling to us, as our sl6 labels conform to specifications for that size.
Imagery-Induced Arousal in Individuals with Panic Disorder

Investigators have debated whether imagery can effectively induce arousal in persons suffering from anxiety disorders. Past research suggests that imaginal exposure to feared stimuli can successfully induce arousal among simple and social phobics. However, owing to the greater complexity of precipitating stimuli associated with panic attacks (PAs), persons with disorder (PD) have been thought to be relatively unresponsive to imaginal exposure. This study evaluated somatic and subjective arousal in individuals with PD, using relaxation, neutral, stress, and panic imagery. Unlike previous investigations, this study incorporated cognitive propositions within the imaginal scenes. As predicted, subjects exhibited significant elevations in heart rate and self-reported distress only in response to stress and panic imagery. Explicit incorporation of meaning elements (e.g., catastrophic attributions regarding the source of PA symptoms) in the imaginal reconstructions seemed integral to the success of the experimental manipulation. Discussion addresses both theoretical and clinical significance of these findings.
A Phenomenological Analysis of the Experience of Pivotal Moments in Therapy as Defined by Clients

This study was concerned with the clarification of the experience of pivotal moments in therapy. By pivotal moment is understood an event within the therapeutic process that leads to enduring change experienced as an important improvement in the life-experience of the client. Retrospective descriptions of a therapeutic process were obtained from three clients in which a distinguishable chain of events could be discerned that the clients identified as a pivotal moment. The descriptive material was analyzed according to the descriptive phenomenological psychological method developed by Amedeo Giorgi on the basis of the philosophical phenomenology of Husserl and Merleau-Ponty. The results show that the pivotal moment is experienced as a figural moment within the therapeutic process where a serious challenge to old assumptions takes place, necessitating a break from old cognitive, affective and behavioral patterns in a context of trust and safety within the therapeutic relationship.
INTERACTION OF GOOSECOID AND BRACHYURY IN XENOPUS MESODERM PATTERNING

Detailed in situ analyses reveal overlapping expression of gsc and Xbra in the early Spemann's organizer. Coexpression is lost during gastrulation suggesting an interaction between these genes. Ectopic expression of gsc ventrally suppresses endogenous Xbra expression and transcription from Xbra promoter reporter gene constructs. Suppression is mediated, at least partially, by a gsc-binding site within the first 349 bp of the promoter. Xbra reporter gene transcription is also suppressed in the region of endogenous gsc expression, whereas high-level ectopic Xbra expression has no effect on endogenous gsc expression. We suggest that early patterning of the vertebrate mesoderm, like early patterning of the Drosophila embryo, occurs by first establishing broad domains of gene expression which are subsequently refined by intergenic interactions to further delimit tissue boundaries.
The Influence of Health Status, Age, and Race on Screening Mammography in Elderly Women

Background Screening mammography is controversial for elderly women because of an absence of efficacy data. Decisions to screen are based on individualized assessment of risks and benefits. Our objective was to determine how screening mammography varies by age and race when adjusted for propensity to die. Methods In a retrospective cohort study, rates of screening mammogram performed in 2000-2001 based on claims, adjusted for propensity to die in 2000, were determined for a nationally representative 5% random sample of female fee-for-service Medicare beneficiaries 65 years and older in (N = 722 310). Results The overall rate of screening was 39%. When stratified into quintiles by propensity to die, 2-year rates ranged from 61% in the lowest-risk group to 5% in the highest-risk group. In analyses stratified by age and adjusted for propensity to die, 42% of women aged 65 to 69 years were screened, declining to 26% of women 85 years and older (P<.001). Adjusted screening rates for white women, black women, and women of other races were 40%, 30%, and 25%, respectively (P<.001). Thus, among women with similar health status, the youngest women were 1.61 times more likely to be screened compared with the oldest; compared with black women and women of other races, white women were 1.38 and 1.60 times, respectively, more likely to be screened. Conclusions Decisions to screen for breast cancer are related not only to health status but also to age and race. Underuse and overuse of screening mammography likely occurs owing to age- and race-associated decision making. Assessment of life expectancy may more accurately identify women who could benefit from screening.
Racemization and the origin of optically active organic compounds in living organisms

The organic compounds synthesized in prebiotic experiments are racemic mixtures. A number of proposals have been offered to explain how asymmetric organic compounds formed on the Earth before life arose, with the influence of chiral weak nuclear interactions being the most frequent proposal. This and other proposed asymmetric syntheses give only sight enantiomeric excess and any slight excess will be degraded by racemization. This applies particularly to amino acids where half-lives of 10(5)-10(6) years are to be expected at temperatures characteristic of the Earth's surface. Since the generation of chiral molecules could not have been a significant process under geological conditions, the origins of this asymmetry must have occurred at the time of the origin of life or shortly thereafter. It is possible that the compounds in the first living organisms were prochiral rather than chiral; this is unlikely for amino acids, but it is possible for the monomers of RNA-like molecules.
Extension of the isotopic method for the determination of oxygen in titanium

Abstract Our method of isotopic elementary analysis has recently been applied to the determination of oxygen in metals. It is now extended to the determination of oxygen in titanium in the low range of 0.04 to 0,2 weight percent oxygen. The method has the great advantage that it gives quantitative results without a quantitative separation of oxygen in any form. In the samples analyzed it was found that the alternative vacuum-fusion method gives results which are 9–13% too low.
Excitable systems in cell motility

2013 marks the fiftieth anniversary of Hodgkin and Huxley's award of the Nobel prize for their studies on action potentials in neurons. This research opened a new field of applied mathematics, the study of excitable systems and excitable media. Recent years have seen several reports suggesting that the migration of certain cells is governed by excitable systems. In this paper, I review certain aspects of the mathematics of excitable systems focusing on their possible role in describing cell motility.
Effect of glucagon on cardiac conduction in man

Abstract His bundle electrograms were obtained in 26 patients before and after intravenous administration of glucagon (50 μg/kg). The group consisted of 4 patients with normal conduction and 22 patients with conduction disease. The P-A interval, measured in all patients, was 35 ± 1.4 msec (mean ± standard error of the mean) before and 30 ± 1.5 msec after infusion of glucagon ( P P P In summary, glucagon increased sinus nodal automaticity, as manifested by an increase in sinus rate and decrease of sinus nodal recovery time, and improved intraatrial conduction as manifested by a reduction of the P-A interval and atrial functional and effective refractory periods. Glucagon had no effect on A-V nodal or intraventricular conduction.
The Rotating Bus as a Basis for Interprocess Communication in Distributed Systems

In the last decade a large number of different interprocess connecting structures and associated protocols were implemented in systems incorporating multiple processors. Efforts in the research of interprocess communication have been intensified in latter years in connection with the research and development of distributed systems. However, most of the developed structures were oriented towards communication between complete computers with full processing power, and involved these computers too much in the communication between processes. What we propose here is more along the lines of the classical bus structure with distributed data propagation and control. Our mechanism is based on the rotating bus concept; it ensures simplicity of interconnecting structures, communication control procedures and very small time overhead in interprocess communication within a computing system using the rotating bus features. It also allows for simple expansion of the system. The mechanism, with completely distributed control, is mainly intended for use in interprocess communication in multi-processor systems, computing systems with distributed architecture and in-house networks linking intelligent terminals.
Global positioning system-based vehicle control for automated parking:

AbstractThis paper addresses control system design for parking of an automated vehicle. The challenge in the control design task for parking arises from the fact that the vehicle constitutes an underactuated non-holonomic system. There are three generalized coordinates to be controlled but only two constrained control inputs. A control system designed to track a two-piece trajectory is developed with only some of the degrees of freedom being controlled in each piece of the trajectory. Constraints on the available parking space, the lateral distance available, and steering limits are taken into consideration in the trajectory design. The trajectory design and control system ensure that the vehicle can reach any desired final point with any desired final orientation.A major portion of the paper concentrates on experimental implementation of the control system. The experimental demonstration is carried out on a truck using a differential global positioning system (GPS) to sense the position of the vehicle. E...
Racial differences in ocular oxidative metabolism: implications for ocular disease.

Objective To compare the PO 2 distribution in different regions in the eyes of patients undergoing intraocular surgery. Methods Before initiation of intraocular cataract and/or glaucoma surgery, an optical oxygen sensor was introduced into the anterior chamber via a peripheral corneal paracentesis. The tip of the flexible fiberoptic probe was positioned by the surgeon for 3 measurements in all patients: (1) near the central corneal endothelium, (2) in the mid–anterior chamber, and (3) in the anterior chamber angle. In patients scheduled to undergo cataract extraction, PO 2 was also measured (4) at the anterior lens surface and (5) in the posterior chamber just behind the iris. Oxygen measurements at the 5 locations were compared using a 2-tailed unpaired t test and multivariate regression. Results The PO 2 value was significantly higher in African American patients at all 5 locations compared with Caucasian patients. Adjusting for age increased the significance of this association. Adjusting for race revealed that age was associated with increased PO 2 beneath the central cornea. Conclusions Racial differences in oxygen levels in the human eye reflect an important difference in oxidative metabolism in the cornea and lens and may reflect differences in systemic physiologic function. Increased oxygen or oxygen metabolites may increase oxidative stress, cell damage, intraocular pressure, and the risk of developing glaucoma. Oxygen use by the cornea decreases with age.