cssi/SciSciGPT-SciSciNet huggingface dataset:
The Genetics of Cerebrovascular Malformations

Certain rare familial or congenital syndromes include cerebrovascular malformations among their constellations of abnormalities. In addition, recognition of familial clustering in a subset of patients with cerebrovascular malformations has led to studies investigating the underlying genetic basis for these lesions. Genetic defects have been identified that cause familial cerebral cavernous malformations and hereditary hemorrhagic telangiectasia, a syndrome that features cerebral arteriovenous malformations. In addition to enhancing presymptomatic screening, identification of the responsible genes may result in a better understanding of the pathogenesis of these lesions, and ultimately, in novel treatments.
High‐Pressure Sintering of Nanocrystalline γAl2O3

High-pressure sintering of nanocrystalline {gamma}-Al{sub 2}O{sub 3} has been studied over a temperature range of 923--1,323 K and at a pressure of 1 GPa. The {gamma}-Al{sub 2}O{sub 3} to {alpha}-Al{sub 2}O{sub 3} transformation temperature changed from 1,473 K without pressure to {approximately}1,023 K at 1 GPa. Full density was obtained at 1,273 and 1,323 K in 10 min. The microhardness value of fully dense {alpha}-alumina with a grain size of 142 nm was found to be 25.3 {+-} 0.8 GPa. The Hall-Petch slope for the very fine grain size range is different from that of the coarse-grained alumina.
Effect of polymer order on the vapor pressures of polypropylene solutions

Abstract The Maron theory of polymer solutions was used to reexamine the data of Brown et al. and Allen et al. [1,2] on the vapor pressures of polypropylene solutions in diisopropyl and diethyl ketones. The results obtained show that the interaction parameters for these systems depend on concentration and temperature, and that these parameters are able to reproduce the observed data so long as the polymers are amorphous. However, in the presence of polymer order, deviations from theory are observed which lead to 31 and 61% crystallinity for the two polypropylene samples used in these studies.
A favorable subset of AJCC stage IV squamous cell carcinoma of the head and neck

Abstract AJCC (American Joint Committee on Cancer) Stage IV is subdivided into a relatively favorable subset, IVA, and an unfavorable subset IVB.
Structural and functional characterization of major platelet membrane components derived by limited proteolysis of glycoprotein IIIa.

Abstract The authors isolated a product of proteolytic degradation of glycoprotein IIIa (GPIIIa) which is formed on the surface of human platelets during incubation with chymotrypsin and which was previously described as the 66 kDa platelet membrane component. This component migrated with an apparent Mr 62400 in a non-reduced system of sodium dodecyl sulfate polyacrylamide gel electrophoresis. In a reduced system it yielded two major subunits migrating with apparent Mr 14000–17000 and 65000. The low-molecular weight component began with the NH2-terminal sequence of GPIIIa (GPNICTTR…) and the larger component with residue 348 of GPIIIa (GKIRSKKA…) as deduced from a cDNA clone of this glycoprotein. The two subunits appeared to be linked by one or more S-S bridges supporting the contention that GPIIIa is a highly folded molecule on the platelet membrane. In contrast to GPIIIa, the ‘66 kDa component’ did not bind to GRGDSPK-agarose, to fibrinogen-agarose nor to insolubilized monoclonal antibody recognizing the GPIIb/IIIa complex. The exposure of fibrinogen receptors during the course of incubation of platelets with chymotrypsin preceded the formation of the ‘66 kDa component’ characterized in this study. An intermediate product of GPIIIa proteolysis migrating with an apparent Mr 120000 in a non-reduced system and Mr 80000 in a reduced system was identified as a precursor of the ‘66 kDa component’. The ‘120 kDa component’ was not retained on GRGDSPK-agarose or on fibrinogen-agarose but it was retained on insolubilized antibody recognizing the GPIIb/IIIa complex. Incubation of platelets with porcine pancreatic elastase or human granulocytic elastase resulted in the formation of similar proteolytic degradation fragments.
Small Molecule Inhibitors of Bacterial Quorum Sensing and Biofilm Formation

Bacteria monitor their local population densities using small molecules (or autoinducers) in a process known as quorum sensing. Here, we report a new and efficient synthetic route to naturally occurring bacterial autoinducers [N-acyl l-homoserine lactones (AHLs)] that is readily amenable to the synthesis of analogues. This route has been applied in the first synthesis of a library of non-native AHLs. Evaluation of these compounds in bacterial reporter gene and biofilm assays has revealed a potent set of quorum sensing antagonists. These ligands will serve as valuable new tools to explore the role of quorum sensing in bacterial pathogenesis.
Electrophysiological and biochemical characteristics of Gymnodinium breve toxins.

Abstract Five toxins (T1–T5) have been isolated from a crude acidified ether extract of unialgal cultures of the dinoflagellate Gymnodinium breve Davis using techniques of column, liquid and thin layer chromatography. Electrophysiological studies using the spontaneously active ventral nerve cord preparation of the crayfish showed that two of the fractions, T2 and T4 caused excitation to more than 250% of control levels at a concentration of 0·05 ng/ml. A blockage of firing occurred at higher concentrations. Fractions T1, T3 and T5 produced gradual excitation only at the higher concentrations. T2 and T4 at a concentration of 250 ng/ml also produced excitation and irregular firing in central neurons from Aplysia californica. Studies on the effect of purified toxins on total choline incorporation in C61A rat glia clone cultures indicate that toxins T2–T5 increase lipid vs nonlipid choline metabolites, presumably by base exchange stimulation. Only T2 stimulated choline uptake in this system.
Experimental evidence of cerebral injury from profound hypothermia during cardiopulmonary bypass

Choreoathetosis, seizures, and impaired mental development continue to occur in children undergoing cardiopulmonary bypass (CPB) and profound hypothermia with or without circulatory arrest. Although there is some evidence that the hypothermia itself may be causing these neurologic problems, skepticism remains because of lack of evidence from experimental studies simulating the clinical setting. In this experimental study, we examined the effect of profound and moderate hypothermia on the brain while maintaining normal flow rates during CPB. Ten adult mongrel dogs equally divided into two groups were anesthetized and subjected to CPB and varying levels of hypothermia (group 1, ≤15°C; group 2, ≤32°C). Both groups were kept at the desired temperature for 1 hour prior to rewarming and discontinuation of CPB. The dogs were euthanized 4–6 weeks later and neuropathologic studies were performed. The mean CPB flow rates during cooling and at the desired rectal temperature were comparable in both groups: group 1, 108 ± 10 ml/kg/min versus 106 ± 7 ml/kg/min in group 2 (p= NS) and 95 ± 12 ml/kg/min in group 1 versus 101 ± 5 ml/kg/min in group 2 (p= NS). Because of the difference in temperature between the two groups, the mean cooling time (onset of CPB to desired rectal temperature) was longer in group 1 (70 ± 14 minutes) than in group 2 (28 ± 11 minutes, p= 0.007). Hence, the total mean CPB time was also longer in group 1 (198 ± 25 minutes) than in group 2 (143 ± 13 minutes, p= 0.002). The lowest mean blood and rectal temperature achieved in group 1 were 11 ± .9°C and 12 ± 1°C versus 29 ± .4°C (p < 0.001) and 30 ± .6°C (p= 0.001), respectively, in group 2 (p= 0.001). Neuronal loss and degeneration was noted in all dogs in group 1 ranging from 2 to 8 cells per 1000 cells counted compared to none in group 2 (p= 0.05). These lesions occurred in both the basal ganglia and the cortex, although they were more marked in the caudate when compared to the cortex and cerebellum. Both in the cortex and in the caudate, neuronal loss was more marked around the capillaries. We conclude that the use of profound hypothermia of ≤15°C and maintenance of normal flow rates during cooling at this temperature for 1 hour produces neuronal loss and degeneration in the brain. These lesions being more marked around capillaries points to the vulnerability of the neurons, probably because of their high lipid content to injury from the cold perfusate.
A frequency domain bootstrap for Whittle estimation under long-range dependence

Whittle estimation is a common technique for fitting parametric spectral density functions to time series, in an effort to model the underlying covariance structure. However, Whittle estimators from long-range dependent processes can exhibit slow convergence to their Gaussian limit law so that calibrating confidence intervals with normal approximations may perform poorly. As a remedy, we study a frequency domain bootstrap (FDB) for approximating the distribution of Whittle estimators. The method provides valid distribution estimation for a broad class of stationary, long-range (or short-range) dependent linear processes, without stringent assumptions on the distribution of the underlying process. A large simulation study shows that the FDB approximations often improve normal approximations for setting confidence intervals for Whittle parameters in spectral models with strong dependence.
Getting back to the "roots" of drug information and looking at the future potential.

Drug information service was one of the first specialty areas of pharmacy practice. The importance of effectively searching, interpreting, and applying the medical literature continues today. The information systems that we use in today’s health care environment have created new opportunities for pharmacists to apply their drug information expertise. We address some of these opportunities this month, along with a brief tie-in to work performed over a decade ago.
Regulation of muscle growth by pathogen-associated molecules,

Skeletal muscle demonstrates great plasticity in response to environmental and hormonal factors including pathogen-associated molecules, inflammatory cytokines, and growth factors. These signals impinge on muscle by forcing individual muscle fibers to either grow or atrophy. We recently demonstrated that skeletal muscle cells express multiple Toll-like receptors (TLR) that recognize bacterial cell wall components, such as lipopolysaccharide (LPS). Exposure of myocytes to LPS and other TLR ligands initiates an inflammatory response culminating in the autocrine production of cytokines and NO by NO synthase (NOS)2. The TLR signal through protein kinases that phosphorylate and promote the degradation of an inhibitory protein that normally retains the transcription factor, nuclear factor kappaB (NFkappaB), in the cytoplasm. Phosphorylation and degradation of the inhibitor of NFkappaB allows for translocation of NFkappaB to the nucleus and activation of inflammatory genes. Overexpression of a constitutively active inhibitor of NFkappaB kinase in skeletal muscle causes severe wasting, and we found that inhibitors of either the phosphorylation of IkappaB or its proteolytic degradation prevent TLR ligand-induced expression of cytokines and NOS2. The combination of LPS and interferon gamma dramatically enhances the magnitude and duration of LPS-stimulated NOS2 expression and reduces protein translation. Lipopolysaccharide and interferon gamma also downregulates signaling from the mammalian target of rapamycin, a kinase that directs changes in cell size. Inhibitors of NOS block the fall in muscle cell protein synthesis and restore translational signaling, indicating that activation of the NOS2-NO pathway is responsible for the observed decrease in muscle protein synthesis. Our work provides a molecular explanation for reduced muscle growth during infection. Muscle is largely self-sufficient because it expresses receptors, signaling pathways, and effectors to regulate its own size. Prolonged activation of NFkappaB and NOS2 have emerged as detrimental facets of the immune response in muscle. The interplay between inflammatory components and growth factor signaling clearly places muscle at the interface between growth and immunity.
Travel Characteristics and Risk-Taking Attitudes in Youths Traveling to Nonindustrialized Countries

Background International travel to developing countries is increasing with rising levels of disposable income; this trend is seen in both adults and children. Risk‐taking attitude is fundamental to research on the prevention of risky health behaviors, which can be an indicator of the likelihood of experiencing illness or injury during travel. The aim of this study is to investigate whether risk‐taking attitudes of youths are associated with travel characteristics and likelihood of experiencing illness or injury while traveling to nonindustrialized countries. Methods Data were analyzed from the 2008 YouthStyles survey, an annual mail survey gathering demographics and health knowledge, attitudes, and practices of individuals from 9 through 18 years of age. Travelers were defined as respondents who reported traveling in the last 12 months to a destination other than the United States, Canada, Europe, Japan, Australia, or New Zealand. Risk‐taking attitude was measured by using a four‐item Brief Sensation‐Seeking Scale. All p values ≤0.05 were considered significant. Results Of 1,704 respondents, 131 (7.7%) traveled in the last 12 months. Females and those with higher household income were more likely to travel (odds ratio = 1.6,1.1). Of those who traveled, 16.7% reported seeking pretravel medical care, with most visiting a family doctor for that care (84.0%). However, one‐fifth of respondents reported illness and injury during travel; of these, 83.3% traveled with their parents. Males and older youths had higher mean sensation‐seeking scores. Further, travelers had a higher mean sensation‐seeking score than nontravelers. Those who did not seek pretravel medical care also had higher mean sensation‐seeking scores ( p = 0.1, not significant). Conclusions Our results show an association between risk‐taking attitudes and youth travel behavior. However, adult supervision during travel and parental directives prior to travel should be taken into consideration. Communication messages should emphasize the importance of pretravel advice, target parents of children who are traveling, and be communicated through family doctors.
Advanced Space Missions and Computer Systems

Computer requirements for future space missions are developed and three different approaches to multiprocessing computer organizations are presented. These approaches are shown to have considerable advantages over conventional computers for advanced space missions. Reliability requirements also are assessed by a simulation method and shown to be attainable for long-duration missions.
Scattering by open metal obstacles in a circular waveguide: dyadic Green's function approach

The problem of scattering from an arbitrarily shaped discontinuity in a circular waveguide is presented. The method of analysis is based on the method of moments (MoM) discretization with the electric dyadic Green's function obtained for a circular waveguide. In this formulation, the Green's dyadic is derived for an arbitrarily oriented electric dipole in the eigenmode expansion form normalized to unity power. Examples of scattering by a thin radial strip and an annular ring are considered, and the results of the scattering parameters are compared with those obtained using a finite-difference time-domain (FDTD) commercial software.
The effects of stress on memory and the hippocampus throughout the life cycle: Implications for childhood development and aging

Studies in animals showing hippocampal atrophy and associated memory deficits in stress and aging have implications for stress and aging in humans. Clinical studies in traumatized human populations with posttraumatic stress disorder (PTSD) have replicated studies in animals, showing reduction in volume of the hippocampus measured with magnetic resonance imaging and associated memory deficits. Trauma at different stages of development (early childhood abuse versus trauma in later life due to combat) may influence the nature of memory deficits and hippocampal atrophy. Studies in aging human subjects are consistent with animal studies, although future research is needed in this area. The similarities between biological findings related to cortisol and the hippocampus in stress and aging in both animal and human studies raises the question of whether PTSD can be seen as a form of accelerated aging. Evidence that stress affects the hippocampus and the capacity for learning has broad implications for public health policy, underlying the need for additional resources in this important area and a reexamination of our understanding of factors influencing academic achievement.
Normotensive hydrocephalus. The relations of pneumoencephalography and isotope cisternography to the results of surgical treatment

An attempt has been made to evaluate the prognostic value for surgery of some diagnostic findings in 15 patients with normotensive hydrocephalus. The results of CSF surgical shunting were considered in relation to the results of pneumoencephalography and isotope cisternography with I131 HSA. In addition, the data obtained by the estimation of the transfer of isotope labelled serum albumin from CSF to blood have been considered. Ten patients showed remarkable improvement following surgery, five did not. From the results of the present study it appears that no one of these diagnostic investigations gives a reliable surgical prognosis which may, however, be obtainable by integrating the results of the different examinations. The following combination of findings appears highly suggestive of good surgical prognosis: ventricular enlargement and everted anterior medullary velum with no signs of cerebral atrophy in the pneumoencephalogram, plus ventricular filling in the isotope cisternographic scans. The additional finding of retention of the isotope labelled serum albumin may further strenghthen the prognostic information.
Stains for Inclusion Bodies

(1974). Stains for Inclusion Bodies. CRC Critical Reviews in Clinical Laboratory Sciences: Vol. 5, No. 1, pp. 70-72.
Sample size calculations in studies of test accuracy

Methods for determining sample size for studies of the accuracy of diagnostic tests are reviewed. Several accuracy indices are considered, including sensitivity and specificity, the full and partial area under the receiver operating characteristic curve, the sensitivity at a fixed false positive rate, and the likelihood ratio. Sample size formulae are presented for studies evaluating a single test and studies comparing the accuracy of tests. Four real examples illustrate the concepts involved in sample size determination. Lastly, various study design issues are discussed, such as sampling methods, choices in format for the test results, and the issue of replicated readings.
Density Functional Theory and Low-Temperature Matrix Investigations of CO-Loss Photochemistry from [(C5R5)Ru(CO)2]2 (R = H, Me) Complexes

The photochemical CO-loss products of the diruthenium complexes [CpRu(CO) 2]2 (5; Cp = η5-C5H5), [Cp*Ru(CO)2]2 (5*; Cp* = η5-C5(CH3)5) and CpCp*[Ru(CO)2]2 (5′) have been studied experimentally in low-temperature (96 K) matrices in 3-methylpentane by using IR spectroscopy. It is proposed that all three complexes undergo single-CO-loss chemistry but that the products have different structures. The single-CO-loss product from 5 is proposed to have one bridging and two terminal carbonyl ligands, whereas 5* and 5′ generate triply bridged CO-loss products similar to that observed from [CpFe(CO)2]2 and [Cp*Fe(CO)2]2. Double-CO-loss from 5* and 5* 9′ is also apparently observed. Relativistic DFT calculations have been carried out on various isomers of the starting materials and on potential CO-loss products from 5. The calculations suggest that the triply bridged product Cp2Ru2(μ-CO)3 (6) might have a singlet ground state in contrast to the corresponding diiron complex Cp2Fe2(μ-CO)3 (3), which has a triplet ground state.
Multiple filtration and approximate pattern matching

Given a text of lengthn and a query of lengthq, we present an algorithm for finding all locations ofm-tuples in the text and in the query that differ by at mostk mismatches. This problem is motivated by the dot-matrix constructions for sequence comparison and optimal oligonucleotide probe selection routinely used in molecular biology. In the caseq=m the problem coincides with the classicalapproximate string matching with k mismatches problem. We present a new approach to this problem based on multiple hashing, which may have advantages over some sophisticated and theoretically efficient methods that have been proposed. This paper describes a two-stage process. The first stage (multiple filtration) uses a new technique to preselect roughly similarm-tuples. The second stage compares thesem-tuples using an accurate method. We demonstrate the advantages of multiple filtration in comparison with other techniques for approximate pattern matching.
A simple method for detection of heterozygous carriers of the gene for classic phenylketonuria

Plasma phenylalanine (Phe) and tyrosine (Tyr) concentrations were measured by high-performance liquid chromatography in arteriolar blood obtained by finger prick from 78 normal volunteers and 36 heterozygote carriers of phenylketonuria (PKU). Subjects were tested at midday, 3 to 4 hours after their breakfast. Values for the micromolar ratio of Phe/Tyr and Phe 2 /Tyr for control subjects fell below 1.2 and 80, respectively; values for all carriers of PKU were higher for one or both ratios. This method should be applicable to widespread screening of the general population for carriers of the gene for PKU.
The aviation paradigm and surgical education.

Q urgical education must change. A new model that satsfies societal imperatives unknown to Dr Halsted must eplace the Halstedian model that served well for almost 00 years. Work hours restrictions, patient safety, cometency based on a curriculum-driven educational expeience, and clearly defined goals and objectives demand more structured and documented residency than has ver existed. Educators are looking for solutions with new technolgy, such as simulators and virtual reality. For this reaon, they often refer to the aviation paradigm of training s one that might guide changes in surgical training. his article focuses on aviation training and, specifically, ighter pilot training. The hypothesis of this descriptive ssay is: Aviation training uses many tools in addition to imulators that are low cost, effective, and can be dapted by surgical educators immediately. Surgical simlators can be expensive and, for the most part, are in the arliest stages of development. A careful examination of kills acquisition and skills maintenance in the fighter ilot community will be beneficial to those who struggle ith the remodeling of surgical education. This article will describe the skills required to fly the ighting Falcon (F-16). Next, it will examine the training rocess: How does one get from high school to flying air ombat missions in the Middle East? The major difference etween skills acquisition and human performance imrovement in aviation and surgery is the mindset and not he simulator; the development of an aviator, and especially fighter pilot, is more carefully monitored and mentored han that of a surgeon.
Peripheral serotonin measures in prepubertal psychiatric inpatients and normal children: associations with suicidal behavior and its risk factors.

Abstract Background: This study reports relationships between suicidal behavior and its risk factors in prepubertal children and whole blood and platelet serotonin-related measures. Methods: Seventy-five prepubertal psychiatric inpatients including 23 (30.7%) nonsuicidal, 32 (42.7%) with suicidal ideation, and 20 (26.6%) with a suicide attempt were compared to 35 normal prepubertal controls with regard to platelet serotonin content, serotonin-amplified platelet aggregation, and whole blood tryptophan. Results: Mean whole blood tryptophan content was significantly lower among inpatient children with a recent suicide attempt than among normal controls or inpatients with suicidal ideation ( F = 3.94, df=3.54, p ≤ .01). Inpatient children with a mood disorder had significantly higher platelet serotonin content than inpatients without a mood disorder ( F = 3.86, df=2,80, p ≤ .03). Racial/ethnic differences were also observed for inpatients and normal controls, with whites having significantly lower levels of platelet serotonin (expressed as ng/mL blood or ng/10 9 platelets) than blacks or Latinos. Blacks had significantly higher levels of whole blood tryptophan than other racial/ethnic groups. Conclusions: The results suggest that whole blood tryptophan and platelet serotonin content should be studied for their predictive validity as risk factors for suicidal behavior in youth while controlling for racial/ethnic differences.
Observer judgmental accuracy of personality: : Benefits related to being a good (normative) judge

The current study tested the hypothesis that accuracy of personality judgment would be positively related to beneficial life outcomes. 189 participants observed targets across 5 dyadic interactions and made judgments of the 10 targets on the Big Five traits. Self and acquaintance ratings were used as the accuracy criteria. Normative accuracy for all traits was related to agreeableness, and normative accuracy for some traits was positively related to interpersonal control, interpersonal support, positive affect, and life satisfaction. Distinctive accuracy was not related to beneficial outcomes. These results imply that normative accuracy based on observation is associated with beneficial outcomes, whereas distinctive accuracy is not.
Design of CO-O2 recombination catalysts for closed-cycle CO2 lasers

Pulsed CO2 lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers is hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalysts and design methods for implementation of catalysts inside lasers. This paper will discuss the performance criteria and constraints involved in the design of monolith catalyst configurations for use in a closed-cycle laser and will present a design study performed with a computerized design program that had been written. Trade-offs between catalyst activity and dimensions, flow channel dimensions, pressure drop, O2 conversion and other variables will be discussed.
Angiotensin II and Endothelin-1 Increase Fibroblast Growth Factor-2 mRNA Expression in Vascular Smooth Muscle Cells☆

Abstract The vasoactive hormone angiotensin II (Ang II) can stimulate vascular smooth muscle cell (SMC) hypertrophy and proliferation; thus, it may have an important role in the pathogenesis of hypertension, atherosclerosis and restenosis. Several studies have indicated that Ang II bioactivity on SMC may depend, at least in part, on its ability to induce the expression of polypeptide growth factors that can function in an autocrine manner. Here we report that Ang II treatment of rat aortic SMC increases fibroblast growth factor-2 (FGF-2) but not FGF-1 mRNA levels. Increased FGF-2 mRNA expression is first detectable at 30 min after Ang II addition and maximal levels are present at 8 hr. Ang II induction of FGF-2 mRNA levels is dependent onde novoRNA and protein synthesis. The Ang II effect can be blocked by treatment with either the Ang II type 1 receptor-selective antagonist CI-996 or the tyrosine kinase inhibitor genistein. The potent vasoconstrictor and SMC mitogen endothelin-1 can also induce FGF-2 mRNA levels in rat aortic SMC. These results indicate that FGF-2 gene expression is up-regulated by two distinct vasoactive peptides implicated in vascular SMC growth controlin vivo.
Ligand-mediated osmium binding: Its application in coating biological specimens for scanning electron microscopy

The osmium-bridging properties of thiocarbohydrazide have been used to bind additional osmium to a variety of soft tissue surfaces before critical-point drying. The procedure gives satisfactory protection to specimens under a scanning electron beam at accelerating voltages between 5 and 25 kV and provides the microscopist with a simple, efficient, and economical alternative to evaporative coating with other heavy metals prior to analysis in the scanning electron microscope.
Identity of trypanosome growth factors in serum. II. Active globulin components.

Abstract This paper describes the identification of the active fractions of rat serum that support the growth and survival of Trypanosoma lewisi in the heterologous mouse host. The relationship between dose of serum and the size of trypanosome challenge was first established. There was reciprocity between the amount of serum and the inoculum, so that at high serum dosages smaller inocula were sufficient for either a viable transfer back to the rat or for a microscopically demonstrable parasitemia in the mouse. At high inocula (> 6 × 107) organisms were detected on transfer back to the rat after 5 days. A problem arising in the fractionation of rat serum was the toxicity of certain preparations to the mouse. Since this effect was also dose dependent it was minimized by adjusting the inoculum size knowing the relationship between protein dose and inocula. Rat serum was then fractionated to determine which components retained the ability to promote T. lewisi parasitemias in the mouse. The proteins were active while the crystalloids were ineffective after their separation by ultrafiltration, dialysis, and Sephadex G-25. Precipitation of the globulins with (NH4)2SO4 and Na2SO4 yielded β and γ globulins which supported gross parasitemias in the mouse and albumin which did not. Further fractionation of the globulins by DEAE and Sephadex G-200 column chromatography, as well as ultracentrifugation, pointed to activity in the γ2 globulins and macroglobulins.
Numerical simulation of two-dimensional electron transport in cylindrical nanostructures using Wigner function methods

We have constructed a lattice Wigner-Weyl code to expand the Buot-Jensen algorithm to calculation of electron transport in two-dimensional cylindrically symmetric structures. Almost all of the numerical simulations to date have dealt with the restricted problem of one-dimensional transport. In real devices, electrons are not confined to a single transport dimension and the coulombic potential is fully present and felt in three dimensions. We show the derivation of the 2D equation in cylindrical coordinates as well as approximations employed in the calculation of the four-dimensional convolution integral of the Wigner function and the potential. We work under the assumption that longitudinal transport is more dominant than radial transport and employ parallel processing techniques. The total transport is calculated in two steps: (1) transport the particles in the longitudinal direction in each shell separately, then (2) each shell exchanges particles with its nearest neighbor. Most of this work is concerned with the former step: A 1D space and 2D momentum transport problem. Time evolution simulations based on these method are presented for three different cases. Each case lead to numerical results consistent with expectations. Discussions of future improvements are discussed.
Genetic and biochemical properties of an association complex between host components and lambda DNA.

Abstract We have used temperate bacteriophage λ to try to elucidate the role of “membrane-complexes” in the regulation of phage development. Membrane association of λ DNA is defined operationally by the conversion of λ DNA to a rapidly sedimenting complex (RSC) after thermal derepression of a superinfected lysogen. Complex formation requires an active N gene product in all cases studied, including those with mutations that bypass the requirement for N for limited rightward or leftward transcription. The complex is formed in the absence of normal λ replication, recombination, integration, excision, and late RNA and protein synthesis. Membrane association is inhibited by repression of the right side operator site for λ cI protein; however, derepression of the left side operator site is not required for complex formation if N is provided by a coinfecting λimm434 phage. Extensive transcription to the left or to the right of the cI gene per se is not required for the formation of the RSC. The complex is sensitive to ionic detergents, DNase, pronase, lipase, and high salt and is resistant to nonionic detergents and RNase. This λ DNA complex is compared with several other “membrane-complexes” that have been reported and its possible role in λ development is discussed.
Ideal-family-size and sex-composition preferences among wives and husbands in Nepal.

This study tests the hypothesis that in Nepal measures of ideal family size mask an underlying preference for sons making some people willing to have families larger than their ideal. Existing evidence suggests that men are likely to have stronger preferences for sons than are women. This research uses empirical evidence to examine the hypothesis that husbands are more willing than their wives to pursue the birth of sons at the cost of an increasingly large completed family size. A Multiple-Response Fertility Preference Scale was developed to test these propositions among a sample of couples. The methodology was successful in demonstrating differential patterns of decision making between husbands and wives that are otherwise obscured by more simplistic single-response measures (for example ideal family size). The results indicate that husbands are consistently more willing than their wives to pursue the birth of sons at the expense of larger family sizes and that the birth of daughters is not pursued to a similar degree by wives or husbands. (authors)
A cone eversion

that is, the bordered Hessian is congruent to the constrained Hessian summed with a saddle point pair. This is the main result in [1]. Applying it to the above example thus requires the diagonalisation of a four by four matrix which, although not difficult to do, is rather tiresome. It is worth emphasising again at this point the importance of the distinction between Hessian matrices and bilinear forms. It is the condition VL(P, A) = 0 which allows us to use bilinear forms to bridge the gap between the above rather special coordinates and the coordinates we are given in the example. Otherwise it would not be clear that our four by four matrix, diagonalised or not, had anything to do with the local behaviour of t|M.
Stimulus and prefood stimulus effects on fixed-interval and fixed-ratio responding

The effects of superimposing a 10-sec stimulus (chamber illumination) at selected points during fixed-interval and fixed-ratio food-maintained responding were examined with rats. The stimulus either did or did not precede response-independent delivery of food. Responding during the initial portion of an interval or ratio was suppressed during the stimulus-alone, but was accelerated when the stimulus preceded food. Responding during the terminal portion of an interval or ratio was minimally suppressed during the stimulus, regardless of whether it did or did not precede food.
The multi-domain method for computation of the aerodynamics of a parachute crossing the far wake of an aircraft

Abstract We present the multi-domain method (MDM) for computation of unsteady flow past a cargo aircraft and around a parachute crossing the aircraft's far wake. The base computational methods used here are the stabilized semi-discrete and space-time finite element formulations developed earlier. In the MDM, the computational domain is divided into an ordered sequence of overlapping subdomains. The flow field computed over Subdomain-1, which contains the aircraft, supplies the inflow boundary conditions for Subdomain-2, which is used for computing the long-wake flow. Subdomain-3 contains the parachute, and moves across Subdomain-2. The boundary conditions for Subdomain-3 are extracted from the flow field computed over Subdomain-2, at locations corresponding to the positions of the boundaries of Subdomain-3 as it crosses Subdomain-2. The computation over Subdomain-1, which contains a complex but fixed object, is based on a general-purpose implementation of the semi-discrete formulation. The computation over Subdomain-2, which contains no objects, is based on a special-purpose implementation that exploits the simplicity of the mesh to increase the computational speed. The computation over Subdomain-3, which contains a complex and moving object, is based on a general-purpose implementation of the space-time formulation. With a numerical example, we show that different methods can be brought together in the context of the MDM to address the computational challenges involved in the aerodynamics of a parachute crossing the far wake of an aircraft.
Electron Density--sensitive Line Ratios for Fe XII in the Solar Corona

The collision strengths for electron-impact excitation of fine-structure transitions from the ground 3s23p3 configuration to the excited 3s3p4 configuration in Fe XII are presented. These are calculated by transforming the K-matrices obtained in a nonrelativistic R-matrix method to K-matrices in intermediate coupling using term-coupling coefficients which take into account the effect of breakdown of target LS coupling. Extensive configuration-interaction wave functions are used to represent the target states. The effective collision strengths are determined assuming a Maxwellian distribution of electron energies. Rydberg series of resonances converging to the excited state thresholds are explicitly included in the calculation. The relative level populations and emission-line strengths for Fe XII are calculated using the new atomic data presented in this paper and that published by Tayal, Henry, and Pradhan (1987) and Tayal and Henry (1986) over a wide range of electron densities and temperatures (1-2 x 10 to the 6th K). Present results for collision strengths and emission-line strengths are compared with the previous calculation of Flower (1977). Some significant differences are noted.
Black Women in Black and White College Environments: The Making of a Matriarch

The social science literature portrays conflicting images of black women: as dominant and assertive, and as the victims of the “double jeopardy” of being both black and female. This paper discusses how predominantly black or predominantly white college environments differentially encourage characteristics associated with each image. Samples of over 500 black females who were freshman or seniors, in one of two all black or four predominantly white colleges, were given a large battery of questionnaires to assess the impact of college. The results show that the adverse conditions of predominantly white colleges were more likely to encourage self reliance and assertiveness, characteristics reminiscent of the “matriarchal” image in social science literature. In contrast, the supportive conditions of predominantly black schools were more likely to encourage a social passivity that may undercut the simultaneous greater academic gains at black colleges. This suggests a dilemma that is characteristic for white women, and perhaps also suggests the image of black women as the victims of double discrimination.
On a Generalized Nonlinear K–ε Model and the Use of Extended Thermodynamics in Turbulence

A resent extension of the nonlinear K–e model is critically discussed from a basic theoretical standpoint. While it was said in the paper that this model was formulated to incorporate relaxation effects, it will be shown that the model is incapable of describing one of the most basic such turbulent flows as is obvious but is described for clarity. It will be shown in detail that this generalized nonlinear K–e model yields erroneous results for the Reynolds stress tensor when the mean strains are set to zero in a turbulent flow – the return-to-isotropy problem which is one of the most elementary relaxational turbulent flows. It is clear that K–e type models cannot describe relaxation effects. While their general formalism can describe relaxation effects, the nonlinear K–e model – which the paper is centered on – cannot. The deviatoric part of the Reynolds stress tensor is predicted to be zero when it actually only gradually relaxes to zero. Since this model was formulated by using the extended thermodynamics, it too will be critically assessed. It will be argued that there is an unsubstantial physical basis for the use of extended thermodynamics in turbulence. The role of Material Frame-Indifference and the implications for future research in turbulence modeling are also discussed.
Anatomic Determinants of Sacral Dysmorphism and Implications for Safe Iliosacral Screw Placement.

Background: Upper sacral segment dysplasia increases the risk of cortical perforation during iliosacral screw insertion. Dysmorphic sacra have narrow and angled upper osseous corridors. However, there is no validated definition of this anatomic variation. We hypothesized that pelves could be quantitatively grouped by anatomic measurements. Methods: One hundred and four computed tomography (CT) scans and virtual outlet views of uninjured pelves were analyzed for the presence of the five qualitative characteristics of upper sacral segment dysplasia. CT scans were reformatted to measure the cross-sectional area, angulation, and length of the osseous corridor. Principal components analysis was used to identify multivariable explanations of anatomic variability, and discriminant analysis was used to assess how well such combinations can classify dysmorphic pelves. Results: The prevalences of the five radiographic qualitative characteristics of upper sacral segment dysplasia, as determined by two reviewers, ranged from 28% to 53% in the cohort. The rates of agreement between the two reviewers ranged from 70% to 81%, and kappa coefficients ranged from 0.26 to 0.59. Cluster analysis revealed three pelvic phenotypes based on the maximal length of the osseous corridor in the upper two sacral segments. Forty-one percent of the pelves fell into the dysmorphic cluster. The five radiographic qualitative characteristics of dysmorphism were significantly more frequent (p 70 had a safe transsacral first sacral corridor. Conclusions: Sacral dysmorphism was found in 41% of the pelves. The major determinants of sacral dysmorphism are upper sacral segment coronal and axial angulation. The sacral dysmorphism score quantifies dysmorphism and can be used in preoperative planning of iliosacral screw placement.
Heterodyne frequency calibration of high resolution cesium spectra using diode lasers

We describe our system for frequency calibrating high resolution laser induced fluorescence spectra. The system utilizes two diode lasers that are spectrally narrowed with optical feedback from external resonators. One laser acts as a reference and is locked to a cesium transition with an external resonator containing a vapor cell in a Faraday filter configuration. Additional electronic feedback fixes the length of the resonator. The second laser receives its feedback from a confocal optical cavity and has the capability of scanning over several hundred megahertz. A portion of the scanning-laser output excites cesium atoms in a thermal atomic beam producing a fluorescence signal. Portions of each laser output are combined on a fast photo diode that produces a heterodyne signal. A counter reads the RF beat note between the laser frequencies and provides the frequency calibration.
Initial collapse of braced elliptical tubes under lateral compression

The initial collapse behavior of elliptical tubes subjected to lateral compression is investigated. Both unbraced and braced tubes are analysed, and the main factors which affect the initial collapse behavior are discussed and interpreted. Lower and upper bound theorems are applied to bracket the collapse load in a direct manner. The initial collapse loads for braced circular tubes, obtained as a special case of elliptical tubes, are compared to previous research results. The results and concepts presented herein can be useful in the development of design criteria for energy dissipating devices. Elliptical shapes, when loaded parallel to their major axes, can have an advantage over their circular counterparts in that they possess larger collapse strokes and an increased energy dissipation potential per unit mass.
Friction Compensation for a Force-Feedback Teleoperator with Compliant Transmission

Friction forces in the joints of manipulators of a force-feedback teleoperator apply unwanted resistant forces to the human operator who moves the master manipulator. The resistant forces contribute to operator fatigue and reduce the transparency of the teleoperator in low frequencies. This paper presents a model-based approach to cancel friction in manipulators of a teleoperator with a compliant tendon drive. Friction compensation reduces the resistant forces applied to the operator and improves the transparency, but it can cause oscillations. This is due to displacement lags between the inputs to the friction compensators and actual displacements of friction contact surfaces that can cause overcompensation around zero velocity. We use a low-stiffness Dahl model to prevent over-compensation around zero velocity. It is shown using passivity theory that the low-stiffness friction compensators preserve the passivity of the teleoperator. Experiments performed on a teleoperator confirm the theoretical results.
Case Studies of High Wind Events in Barrow, Alaska: Climatological Context and Development Processes

The Beaufort‐Chukchi cyclones of October 1963 and August 2000 produced the highest winds ever recorded in Barrow, Alaska. In both cases, winds of 25 m s21 were observed with gusts unofficially reported at 33 m s 21. The October 1963 storm caused significant flooding, contaminated drinking water, and interrupted power supplies. The August 2000 storm caused the wreck of a $6 million dredge, and removed roofs from 40 buildings. Both storms were unusual in that they tracked eastward from the East Siberian Sea into the Chukchi and Beaufort Seas, rather than following a more typical northward track into the Arctic Ocean. This paper addresses, through modeling and analysis, the development processes of these two storms. The October 1963 system was a long-lived, warm core, zonally elongated cyclone that traversed around the Arctic basin through the Canadian Archipelago. The August 2000 system was an open-wave cyclone that dissipated rapidly into a weak, cold core eddy in the Alaskan sector of the Beaufort Sea. Approximating the contributions to development using terms in a quasigeostrophic omega equation, it was found that both storms were characterized by the increasing importance of the convergence of the Q vector (representing differential vorticity advection and thermal advection) in the midtroposphere, at the expense of forcing by the turbulent fluxes of heat, moisture, and momentum in the boundary layer. However, the influence of surface turbulent fluxes in the early stages of development was important, particularly for the August 2000 cyclone, which passed over an extensive coastal lead in the East Siberian Sea. This study concludes that the observed retreat in western Arctic ice cover is unlikely to be an important contributor to increasing cyclonic activity in the region, but that ice retreat north of Eurasia could have an impact.