cssi/SciSciGPT-SciSciNet huggingface dataset:
VIRUS BIOGRAPHIES I. Growth of West Nile and Guaroa Viruses in Tissue Culture

Southam, Chester M. (Sloan-Kettering Institute for Cancer Research, New York, N.Y.), Frederick H. Shipkey, Virginia I. Babcock Roller Bailey, and Robert A. Erlandson. Virus biographies. I. Growth of West Nile and Guaroa viruses in tissue culture. J. Bacteriol. 88:187-199. 1964.-Monolayer tissue cultures of HEp 2 cells (human epidermoid carcinoma) were inoculated with Guaroa or West Nile viruses. At daily intervals for 4 days thereafter, these cultures were studied by (i) light microscopy of living cultures and stained cultures, (ii) intracerebral inoculation of mice to titrate infectivity, (iii) acridine orange stain to observe nucleic acid changes, (iv) fluorescein-labeled antibody technique to observe specific viral antigen, and (v) electron microscopy to observe virus particles. Guaroa virus infectivity increased progressively over the 4-day period, and caused definite cytolysis by day 3. Cytoplasmic ribonucleic acid (RNA) staining was increased by 24 hr, and by 48 hr the RNA formed globular masses, particularly in degenerating cells. Viral antigen was occasionally seen on day 1, and increased progressively thereafter, forming numerous sharply outlined particles in cytoplasm concentrated at the cell membrane. Virus particles were ellipsoids with a dense nucleoid and a single membrane approximately 70 by 90 mmu, which appeared to form at the cell membrane just before being discharged. West Nile virus infectivity increased sharply between 1 and 2 days, but caused little cytolysis even by 4 days. Cytoplasmic RNA staining increased progressively for the 4 days, usually forming a large juxtanuclear mass in each affected cell. Viral antigen was not detected on day 1, but increased progressively thereafter, forming a crescent or a single diffuse mass adjacent to the nucleus. Virus particles were spheres approximately 30 mmu in diameter, with a dense nucleoid and a single membrane. They appeared to form in granular foci in the cytoplasm and then to fill the channels of the endoplasmic reticulum. No significant nuclear changes were observed with either virus by any of these techniques.
Sleep complaints in cerebral palsy and/or epilepsy: A pediatric sleep questionnaire study

This study determined whether common symptoms of sleep disorders were more prevalent in children with cerebral palsy (CP), epilepsy, and with CP comorbid with epilepsy. The pediatric sleep questionnaire was administered to the guardians of healthy control children (n = 69), children with CP (n = 23), epilepsy (n = 106), and CP comorbid with epilepsy (n = 29). Scores on symptoms of sleep disordered breathing, insomnia, and excessive daytime sleepiness were analyzed separately and compared among the groups using Kruskal-Wallis analysis of variance by ranks. In comparison to controls, the CP group had a significantly higher prevalence of sleep disordered breathing, insomnia, and excessive daytime sleepiness, and the CP comorbid with epilepsy group exhibited significantly higher prevalence of sleep disordered breathing and insomnia. The epilepsy group showed significantly higher prevalence of sleep disordered breathing than controls. The sleep complaints were more common in this cohort of children with CP and/or epilepsy that deserve clinical attention for proper diagnosis and treatment of sleep disorders.
Definition and assessment of surgical patients' welfare and recovery. Selected review of the literature.

Selected studies concerned with assessing surgical patients' recovery and welfare are briefly reviewed to point out the major types of direct criterion measures that have been used to measure the outcome of nursing procedures. There has been a tendency to operationalize patient recovery and welfare, primarily in terms of physical, rather than psychological, aspects. Rased on a theoretical distinction between physical “recovery” and psychological “welfare,” it is recommended that more direct measures of psychological welfare, particularly self-report measures, be developed and tested in order to evaluate nursing interventions explicitly designed to change a patient's affective and cognitive stale. Limitations of some of the more frequently used measures of recovery are discussed along with methodological problems associated with self-report measures.
Innovative newsletter interventions improve fruit and vegetable consumption in healthy adults

Abstract Objective To evaluate the effectiveness of computer-tailored newsletter interventions in improving the number and variety of fruits and vegetables eaten by adults. Design The 4-group randomized trial with pre- and post-intervention measures consisted of a control group and 3 intervention groups receiving nontailored newsletters, computer-tailored newsletters, or tailored newsletters with tailored goal-setting information. Intervention groups received 1 newsletter each month for 4 months. Subjects Baseline surveys were completed by 710 health maintenance organization clients. Postintervention surveys administered 6 months after baseline were completed by 573 participants (80.8%). Intervention All newsletters contained strategies for improving fruit and vegetable consumption. Tailored newsletters used computer algorithms to match a person's baseline survey information with the most relevant newsletter messages for promoting dietary change. Main outcome measures Daily intake and weekly variety of fruits and vegetables were measured using a food frequency questionnaire. Statistical analyses performed Analysis of covariance and Tukey's honestly significant difference test were used to assess differences in the number and variety of fruits and vegetables consumed among intervention groups. Results For persons completing postintervention surveys (n=573), all 3 newsletter groups had significantly higher daily intake and variety scores compared with the control group. Although there was a trend of improved intake and variety with each added newsletter element, there were no significant differences at follow-up among the newsletter groups. Conclusions Newsletters can be effective in improving the fruit and vegetable consumption of adults. In this study, a computer-tailoring system did not significantly enhance the effect of the nutrition newsletters on fruit and vegetable intake. J Am Diet Assoc. 1999;99:705–709 .
Inhibition of abscisic acid biosynthesis in Cercospora rosicola by triarimol.

The fungicide triarimol was tested for its effect on abscisic acid (ABA) accumulation in growing culturesof Cercospora rosicola. ABA accumulation was reduced by approximately 50% with 10−8 M triarimol. Growth ofC. rosicola, as measured by dry weight accumulation, was inhibited by triarimol concentrations at or greater than 10−7 M. These results are compared with those obtained with clomazone, ancymidol, and paclobutrazol, which inhibit ABA accumulation by 50% at concentrations of 5 × 10−5, 5 × 10−6, and 5 × 10−7 M, respectively. Triarimol, therefore, is among the most potent inhibitors of ABA biosynthesis reported to date. Feeding studies with [14C]mevalonic acid confirmed the inhibition of ABA biosynthesis by 5 × 10−8 M triarimol. These results support previous suggestions that one or more of the steps in the ABA biosynthetic pathway from mevalonic acid is catalyzed by cytochrome P-450. Feeding studies with 1′-deoxy-[2H]-ABA in resuspended cultures ofC. rosicola show that the conversion of this substrate is not inhibited by triarimol.
Induced triploidy in the bay scallop, Argopecten irradians, and its effects on growth and gametogenesis

Abstract Triploidy was induced in the bay scallop, Argopecten irradians , by treating newly fertilized eggs with cytochalasin B. Treatment for 20 min duration 10 min after fertilization resulted in 66% triploidy of scallops in the 0.05 mg/l cytochalasin treatment group and 94% triploidy of scallops in the 0.1 mg/l cytochalasin treatment group, detected by measuring the relative DNA content of scallop granulocytes using flow cytometry. Individually labelled scallops of known ploidy were grown in the Damariscotta River estuary in south-central Maine, U.S.A. from May 24 to September 15, 1982. Mean adductor muscle weight in triploid scallops was 73% greater than that of diploid controls and mean total body tissue wet weight was 36% greater. Shell inflation was significantly greater in triploids, while shell height and length were unaffected. The indexes of weight and glycogen content of the adductor muscle were significantly greater in triploids at the end of the growing season. The majority of triploid scallops failed to ripen during the summer months, while diploid scallops ripened and spawned.
5-HT1A receptor dysfunction in female patients with schizophrenia

Abstract Background: Serotonin (5-HT) 1A receptors are of interest in the pathophysiology of schizophrenia (SCH) and the mechanism of action of atypical antipsychotic drugs. To test the hypothesis that 5-HT 1A receptor responsivity is significantly different in patients with SCH compared to normal control subjects, the neuroendocrine study was performed using ipsapirone (IPS), a 5-HT 1A partial agonist, as a probe. Methods: Ipsapirone 0.5 mg/kg, p.o. or placebo were administered, in random order, to patients with SCH (n = 43; 32 male) and normal controls (n = 33; 21 male). Blood samples for plasma cortisol and body temperature were obtained from 30 min before to 180 min after administration of IPS or placebo. Results: Female normal control subjects had markedly greater increases in plasma cortisol following IPS than did male control subjects. The placebo response-corrected plasma cortisol response to IPS was significantly blunted in female SCH compared to female normal control subjects (p = .0001). The IPS-stimulated plasma cortisol response in male SCH did not differ from that of male normal control subjects or female SCH. There were no significant differences in the IPS-induced hypothermia in men and women or between patients with SCH and normal control subjects. Behavioral responses to IPS, including nausea, dizziness, irritability, and feeling less well, did not differ between groups. Conclusions: These results suggest that the post-synaptic 5-HT 1A receptor mediated endocrine response is diminished in female SCH compared to female normal control subjects, possibly secondary to an abnormality in intracellular signal transduction mechanism.
Such: Binding and the pro-adjective

The facts aboutsuch, then, indicate not just thatsuch is a pro-adjective, but also that binding conditions apply broadly to pro-ADJs and pro-CNs, as well as to a wide range of pro-arguments. If this is true, the CN binding process accomplished by rules (40) and (41) might better be expressed in a system that uses a Cooper (1979) store mechanism. In fact, Stump (p. 144) notes that this could easily be done. Meanings of the type of∨ P n could be stored, just as NP meanings are, until an appropriate binding CN phrase was encountered. Binding conditions would simply require that a∨ P n meaning not come out of storage until the derivation had emerged from its governing category. The behavior of the pro-adjectivesuch suggests that an expression of any category, if it is legitimately translatable as a variable, may be a fullfledged proform; many principles and mechanisms described to account for the widely studied pronouns in fact apply to nonargument categories.
Which patients with suspected myocardial ischemia and left bundle-branch block should receive thrombolytic agents?

Abstract [Gallagher EJ. Which patients with suspected myocardial ischemia and left bundle-branch block should receive thrombolytic agents? Ann Emerg Med. May 2001;37:439-444.]
Functionalization of AlN surface and effect of spacer density on Escherichia coli pili-antibody molecular recognition

Abstract The immobilization of antibodies to sensor surfaces is critical in biochemical sensor development. In this study, Jeffamine spacers were employed to tether Escherichia coli K99 pilus antibody to AlN/sapphire surfaces which may allow the antibody to freely reorient and potentially improving the antigen capture efficiency. Spacer density was one of the key parameters to be optimized in studying its effect on the immobilization of antibody. The spacer density was controlled by functionalizing AlN/sapphire surfaces with a mixed (3-glycidyloxypropyl)trimethoxysilane (GPTMS) and trichloro(1 H ,1 H ,2 H ,2 H -perfluoroctyl)silane (FAS) self-assembled monolayer (SAM) through a step-wise method. Contact angle measurement and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface coverage of GPTMS and surface chemical composition. Compared to spacer fully covered samples, the capture efficiency was improved by ∼28% with optimal Jeffamine ED 600 spacer density, which depends on the spacer properties such as the number of monomer units and its size.
Discontinuous quantum evolutions in the presence of closed timelike curves

We consider Deutsch's computational model of a quantum system evolving in a spacetime containing closed timelike curves. Although it is known that this model predicts nonlinear and nonunitary evolutions of the system, we demonstrate that it also gives rise to evolutions which are a discontinuous function of the input state. These discontinuities persist for the most natural modifications of Deutsch's approach.
A computer simulation model of the afferent part of the visual foveation system

It is argued that the duplicity notion of visual perception refers to two separate neural systems, the foveation and identification system. A computer simulation model for the afferent part of the foveation system was developed. It consists of a receptive matrix and a retinal, geniculate, and cortical network. Within the networks neurons were substituted by threshold gates. The retinal information of the model can be controlled by the geniculate network and is analyzed with regard to stimulus orientation and movement by hypercolumns of cortical gates. The implemented columnar organization preserves retinocortical continuity. Retinal and cortical information together provide the necessary prerequisites for the efferent part of the foveation system.
A study of factors that affect the information-seeking behavior of academic scientists

In an effort to understand how academic scientists seek information relevant to their research in today's environment of ubiquitous electronic access, a correlation framework is built and regression analysis is applied to the survey results from 2,063 academic researchers in natural science, engineering, and medical science at five research universities in the United States. Previous work has reported descriptive statistics about these scientists' information-seeking behavior. This study extends that work to examine relationships between scientists' information-seeking behaviors and their personal and environmental factors. Several regression models, including the Poisson model, the logit model, and the ordered logit model, are built to interpret the correlation among scientists' behaviors. In addition, exploratory factor analysis is used for data reduction. Overall, many factors were found to affect the specific information-seeking behaviors of scientists, including demographic, psychological, role-related, and environmental factors. Of the factors having an effect, academic position was the most important determinant of information behavior. © 2012 Wiley Periodicals, Inc.
The Intentional Use of Metaphor in Counseling Supervision

In this multiple case study, the intentional use of metaphor in supervision was examined to determine its impact on (1) supervisees’ recall of supervision events, (2) supervisees’ perceptions of the effectiveness of supervision, and (3) supervisees’ ability to conceptualize clinical situations.
The Influence of Counselor Epistemology on the Helping Interview: A Qualitative Study

The relationship between certain personal qualities of a counselor and the outcomes of counseling has been well established. In this qualitative study, the authors sought to extend this understanding by examining the relationship between the personal epistemologies of counselor trainees and their interview behaviors. Five distinguishing themes emerged.
Some properties of mouse platelets

Mouse platelets were aggregated by arachidonate, thrombin, collagen and ADP. In general they were, like rat platelets, more aggregative in heparinized PRP than in citrated (3.8%) PRP. Mouse platelets underwent the release reaction when aggregated by arachidonate, collagen and thrombin, but not when stimulated by ADP. The aggregation of the platelets to arachidonate was inhibited by cyclooxygenase inhibitors and by prostacyclin. Studies with tritiated arachidonate showed that mouse platelets possess the lipoxygenase and cyclooxygenase pathways found in other mammalian platelets and produce thromboxane and 12-HETE. The mouse provides a convenient model for the study of many conditions known to affect platelet aggregation. The similarity of mouse platelets to the platelets of other mammals together with the ability to study large numbers of animals at low cost, should encourage further use of mouse platelets.
The role of porous polymeric materials in prosthesis attachment

Polymeric materials are becoming increasingly popular as prosthetic materials in orthopedic surgery. One of these materials, polyethylene, is capable of being fabricated in a porous form suitable for tissue ingrowth. Porous polyethylene appears to be well suited for prosthesis attachment when bonded to its solid form of other prosthetic materials. Extensive bone growth into porous cylindrical specimens implanted in the canine femur has occurred as early as four weeks. Ingrown tissues appear normal and there is minimal inflammatory response. Mechanical strength of the porous material, though not as great as that of the solid material, does appear to be sufficient for certain orthopedic applications. Current research is directed toward determining interfacial strengths and the mechanical properties of the porous polyethylene-bone composite.
Antiferromagnetic bubbles around nonmagnetic impurities

An explanation is proposed for the experimentally observed phenomenon of an antiferromagnetic spin polarization around nonmagnetic impurities, Zn and Li, in the metallic state of layered copper oxides. The explanation is based on the idea that the impurity ion, creating an excess positive charge at the copper site, reduces the hole concentration in its vicinity, and this leads to the appearance of a bubble of a an insulating spin-density wave phase around the impurity.
Piezoelectric effects in (001)‐oriented double barrier resonant tunneling structures

We show that piezoelectric effects can give rise to internal electric fields that modify the current–voltage characteristics of double barrier resonant tunneling devices, if suitable stresses are applied. Electric polarization fields in the direction perpendicular to the interfaces arise in heterostructures on (001)‐oriented substrates under uniaxial stress parallel to the (110) or (110) orientations. We measured current–voltage characteristics of (001)‐oriented AlAs/GaAs/AlAs double barrier structures as a function of uniaxial external stress applied parallel to the (110) and the (110) orientations. The substrate contact was grounded in all measurements. Under (110) stress, the resonance peaks shift to more positive voltages for both positive and negative bias. For (110) stress, the peaks shift toward more negative voltages. We also calculated the current–voltage characteristics of resonant tunneling structures under uniaxial stress, taking into account stress effects on the band alignment and piezoelectric effects. We obtain satisfactory agreement between our calculations which contain no adjusted parameters and the measured data.
"The Days Now Is Very Hard for My Family": The Negotiation and Construction of Gendered Work Identities Among Newly Arrived Women Refugees

Recent studies of second language learning and language contact in bilingual and multilingual communities have been informed by feminist poststructuralist approaches to the study of language, gender, and identity (Cameron, 1997; Cameron, Frazer, Harvey, Rampton, & Richardson, 1992; Eckert & McConnell-Ginet, 1992; Erhlich, 1997; Norton, 2000; Norton Peirce, 1995; Pavlenko & Piller, 2001). Viewing gender as a composite of social and economic relations as well as a set of discursive practices, such research focuses on the various ways that ideologies (of language and of gender) mediate those social and economic relations. I utilize such frameworks to analyze the multiple and complicated ways that identities are constructed, negotiated, and deployed within specific situations and circumstances. Examining data from long-term participant observation and recorded interviews, I ask how individual refugee women who have recently arrived in the U.S. are positioned and position themselves as language learners and as...
PHOTODYNAMIC AND SUNLIGHT INACTIVATION OF ESCHERICHIA COLI STRAINS DIFFERING IN NEAR-UV SENSITIVITY AND RECOMBINATION PROFICIENCY

— Stationary cells of four Escherichia coli strains exhibiting all four possible combinations of genes controlling near-UV sensitivity (nur vs nur+) and recombination proficiency (far-UV sensitivity; recA1 us recA+) have been inactivated by visible light in the presence of acridine orange (AO, 10µg/ml) and sunlight. The results demonstrate that strains sensitive to near-UV inactivation are also sensitive to inactivation by visible light in the presence of AO and sunlight irrespective of the recA allele carried by the strain. These results may be interpreted to mean that major mechanisms of inactivation of stationary E. coli cells by near-UV, visible light in the presence of AO and sunlight are similar and not closely related to the mechanism of inactivation by far-UV.
Characterization of Stable Fly (Diptera: Muscidae) Larval Developmental Habitat at Round Hay Bale Feeding Sites

ABSTRACT In this study, we examined the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), larval developmental habitat within the round hay bale feeding sites on cattle pastures, and we identified three zones with distinct characteristics around two types of hay feeders (ring and cone). The parameters monitored in each zone included stable fly emergence, substrate temperature, moisture, pH, thickness of hay-manure layer, and concentration of fecal coliform bacteria (Escherichia coli and Klebsiella oxytoca) as indicators of fecal material. All measurements were conducted during the period of high stable fly prevalence (HSF) in May-June and low stable fly prevalence (LSF) in July-August to better understand the environmental factors influencing stable fly seasonality. Substrate temperature and fecal coliform concentration were the only two significantly different factors between HSF and LSF. Temperatures ranged from 21 to 25°C during HSF versus 25–30°C in LSF but all were within the range for succes...
Optimal expansion of subspaces for eigenvector approximations

We consider the problem of how to expand a given subspace for approximating an eigenvalue and eigenvector of a matrix A. Specifically, we consider which vector in the subspace, after multiplied by A, provides optimal expansion of the existing subspace for the eigenvalue problem. We determine the optimal vector, when the quality of subspace for approximation is measured by the angle between the subspace and the eigenvector. We have also derived some characterization of the angle that might lead to more practically useful choice of the expansion vector.
Cytotoxic and genotoxic potential of dopamine

A variety of in vitro and in vivo studies demonstrate that dopamine is a toxic molecule that may contribute to neurodegenerative disorders such as Parkinson's disease and ischemia-induced striatal damage. While much attention has focused on the fact that the metabolism of dopamine produces reactive oxygen species (peroxide, superoxide, and hydroxyl radical), growing evidence suggests that the neurotransmitter itself may play a direct role in the neurodegenerative process. Oxidation of the dopamine molecule produces a reactive quinone moiety that is capable of covalently modifying and damaging cellular macromolecules. This quinone formation occurs spontaneously, can be accelerated by metal ions (manganese or iron), and also arises from selected enzyme-catalyzed reactions. Macromolecular damage, combined with increased oxidant stress, may trigger cellular responses that eventually lead to cell death. Reactive quinones have long been known to represent environmental toxicants and, within the context of dopamine metabolism, may also play a role in pathological processes associated with neurodegeneration. The present discussion will review the oxidative metabolism of dopamine and describe experimental evidence suggesting that dopamine quinone may contribute to the cytotoxic and genotoxic potential of this essential neurotransmitter.
A comparison of dynamic- and static-strength models for prediction of lifting capacity

Abstract An experiment was designed and conducted for the development, testing and comparison of models for prediction of weight lifting capacity of individuals incorporating static and dynamic strengths. The dependent variable was the maximum acceptable amount of lift and the independent variables were static strengths, and dynamic strengths of the individual in a simulated lifting position and task variables—height and frequency of lift. Data from nine male subjects were used for analysis. It was concluded that both the dynamic and static models developed in this study can predict the maximum acceptable amount of lift with a reasonable degree of accuracy. However, a comparison of the models revealed that the use of the dynamic model with one operator variable resulted in less absolute error between the actual and predicted load than the static model. This study, which is based on data from a limited number of subjects, indicates that the dynamic approach may be superior to the static approach.
Sex differences in nonverbal behavior.

A variety of nonverbal behaviors was coded from videotapes of 88 dyadic conversations. The 44 male and 44 female subjects were paired so that each participated in one conversation with a stranger of the same sex and one conversation with a stranger of the opposite sex. It was found that sex of subject, but not sex of partner, had a significant effect on many of the nonverbal behaviors displayed during the conversations. Subjects' scores on the behavioral measures were correlated with their scores on several personality measures and on a post-conversation questionnaire. Sex differences in these correlations were used to generate hypotheses linking specific behavioral differences between the sexes to more general differences between the masculine and feminine interpersonal styles.
Catastrophic events in a surface mixed layer

THE formation and evolution of mixed layers in the surface waters of the oceans are important in many fields of study and much effort has been expended towards the development of predictive models of the wind-mixed surface layer1,2. These models parameterise small-scale high-frequency turbulent mixing processes, which are difficult to measure, in terms of more easily observed variables such as the wind stress. Because this parameterisation depends on hypotheses about the character of the turbulent mixing which dominates the transport of heat and momentum, it is vital to have a realistic concept of the turbulent processes in active mixing layers. It is often assumed that a major source of turbulence at the base of the mixed layer is the shear between the mean currents in the mixed layer and those in the thermocline. Simple shear turbulence of this sort often may be described by a flux-gradient relationship3. We have now found that although a flux-gradient description is adequate most of the time at the base of an actively mixing layer, during a storm isolated and relatively rare large-scale catastrophic mixing events, which cannot be described by a flux-gradient relation, can dominate transport. Although these catastrophic events occur infrequently, the vertical heat transport associated with them can dominate the continuous transport associated with flux-gradient processes.
Photolabeling of glucose-sensitive cytochalasin B binding proteins in erythrocyte, fibroblast and adipocyte membranes.

(3H)Cytochalasin B has been photoincorporated into membrane fractions of the human erythrocyte, Rous sarcoma virus-transformed chicken embryo fibroblast and rat adipocyte. Identification of D-glucose sensitive cytochalasin B binding sites was achieved by photolyzing membranes with radioligand in the presence of 0.5–0.7M D- or L-glucose. In the erythrocyte the major labeled bands on SDS-polyacrylamide gels were at 55,000 and 46,000 daltons. In the virus-transformed fibroblasts a major labeled band was at 55,000 daltons, and in adipocyte microsomal membranes, peaks at 50,000 and 45,000 daltons were observed. Binding characteristics of these polypeptides suggest that they are the putative glucose transport proteins in these three cell types.
Wave space interpretation of scattered ultrasound

Wave space is described nonmathematically for design and interpretation of ultrasound scattering experiments. By considering ultrasound scattering from a variety of targets and geometries, the wave space approach is shown to describe target characteristics in terms of spatial frequencies and their amplitudes. Experimental limitations for determining effective spacing of scattering structures and scattering medium anisotropy are discussed.
An investigation of non-programmers' performance with tools to support output localization

The wealth of code available through the web has the potential to dramatically change the way we learn to program. This includes inexperienced programmers, who may struggle to find code in example programs that relate to observable program features. We present a comparative study of three tools for assisting non-programmers with finding program code corresponding to a program's graphical output. From this study we also identify a model which captures the goals inherent in non-programmers' code search processes for this type of search task. Our results suggest a global pause marker may be an effective tool to support non-programmers' search.
Performance Limits and Analysis of Contention-based IEEE 802.11 MAC

Recent advance in IEEE 802.11 based standard has pushed the wireless bandwidth up to 600Mbps while keeping the same wireless medium access control (MAC) schemes for full backward compatibility. However, it has been shown that the inefficient protocol overhead casts a theoretical throughput upper limit and delay lower limit for the IEEE 802.11 based protocols, even the wireless data rate goes to infinitely high. Such limits are important to understand the bottleneck of the current technology and develop insight for protocol performance improvements. This paper uses a queuing system approach to extend the discussions of IEEE 802.11 protocol throughput and delay limits to the situation that arbitrary non-saturated background traffic is present in the network. We derive analytical models to quantify the performance limits for Distributed Coordination Function (DCF) of legacy 802.11a/b/g and Enhanced Distributed Coordination Access (EDCA) of IEEE 802.11e. We find such limits are functions of the underlying MAC layer backoff parameters and algorithms, and are highly dependent on the load that background traffic injects into the network. Depending on the rate of arrival traffic, the packet delay limit may become unbounded such that no delay sensitive services can be operated under such condition. Moreover, we also discuss the effects of different frame aggregation schemes on the performance limits when data rate is infinite. The developed model and analysis provide a comprehensive understanding of the performance limitations for IEEE 802.11 MAC, and are useful in gauging the expected QoS for the purposes such as admission control.
Persuasive Appeals and Responses to Appeals among Friends and Acquaintances

JONES, DIANE CARLSON. Persuasive Appeals and Responses to Appeals among Friends and Acquaintances. CHILD DEVELOPMENT, 1985, 56, 757-763. This study examined persuasive appeals and responses to appeals among kindergarten, second-, and fourth-grade friends and acquaintances. It also evaluated social perspective-taking, friendship, and self-interest reasoning as predictors of appeals and responses to them. Based on sociometric ratings, children were paired with a friend or an acquaintance and participated in a task designed to examine sharing under competitive conditions. Results indicate that appeals to friends and acquaintances did not differ in kind or rate of success. Children of all ages and in all conditions tended to use simple requests most frequently. Friendship status had its most noticeable effect on responses to appeals. Grants were more likely to occur among friends and, when an appeal was rejected, refusals to friends were more extended. Multiple regression analyses revealed that different predictor variables were linked to different appeal and response measures. Further, the behavioral explanations, friendship, and self-interest reasoning, were more frequently related to the appeal and response measures than was hypothetical reasoning. These results document the need for a comprehensive approach in order to describe persuasion among friends and acquaintances.
Some Applications of Computerized GC-MS to the Determination of Biogenic and Anthropogenic Organic Matter in the Environmentt

Abstract This is an overview of the application of organic mass spectrometry and ancillary techniques to the analysis of organic matter in environmental research. Such organic matter is usually analyzed in terms of gas, bitumen (lipids), and “kerogen”, with asphaltenes and humic substances for some samples. This approach is illustrated with some examples and the origin, the environmental history and the nature of secondary products of this organic matter can be evaluated by using the data derived from both specific molecular and bulk chemical (also physical) analyses. Evaluations of production and fluxes and cross-correlations can thus be made by the application of the same separation and analytical procedures to samples from different environmental compartments (eg., biota, atmosphere, hydrosphere, lithosphere, etc.).
Tax reform and individual giving to higher education

Abstract Higher education benefits from a number of special provisions of U.S. tax laws. One of the most important is the deducibility of charitable contributions. One effect of recent proposals for tax reform would be to increase the net cost to donors of making such gifts, thereby reducing current tax incentives to give. Higher education would be especially impacted by such proposals because of its dependence on gifts from high income donors and on gifts of appreciated property. Simulations of taxpayer behavior under the assumption of a passive response by higher education institutions and contributors imply that tax reform could lead to a significant reduction in giving.
The explicit gauge invariance of the free closed bosonic strings and open fermionic string

We derive the gauge invariant equations of motion for the open Ramond superstring and closed string theories. We show that the actions which give the equations of motion for all the closed string theories are quite similar in form and require the introduction of an auxiliary field.
Use of micromachined probes for the recording of cardiac electrograms in isolated heart tissues.

Abstract Micromachined probes, with iridium (Ir) microelectrodes on silicon shanks, were evaluated to assess their suitability for cardiac electrogram recording. The electrochemical activation (anodic oxidation) procedure for the circular Ir microelectrode was investigated using the square wave potential according to the electrode size, number of cycles, and cathodic–anodic potential level of the square wave. Increase in the charge storage capacity was pronounced either in smaller electrodes or with higher potential level of the square wave. The electrode impedance reduced in a similar manner with increasing number of cycle irrespective of the electrode size. With either lower potential level (−0.70/+0.60 V) or smaller number of cycle (200 cycles) than those for the activation of stimulating electrode, the likelihood of overactivation of the recording microelectrode can be minimized. These anodic IrOx film (AIROF) microelectrodes were used for the recording of extracellular electrograms in two different ex vivo cardiac tissue preparations. A single-shank microprobe was applied to the left ventricle of a mouse heart. Both the spontaneous and paced transmural responses propagating between epicardium and endocardium were obtained. Longitudinal cardiac wavefronts propagating along the rabbit papillary muscle were also recorded with a unique multiple-shank design. The measured mean amplitude and the propagation velocity of the extracellular voltage were 12.2±1.8 mV and 58.9±2.2 cm/s, respectively (n=27). These microprobes with precisely defined electrode spacing make a useful tool for the spatial and temporal mapping of electrical properties in isolated heart tissues ex vivo.
Determination of anion concentrations in individual snow crystals and snowflakes

Abstract Capillary electrophoresis (CE) was used to measure the concentrations of chloride, sulfate and nitrate in snowflakes and in individual snow crystals. Present handling operations allow analyses to be performed on sample volumes as small as 0.3 μl (e.g. ≈ 1 mm dia. spatial dendrite). Preliminary findings suggest that the anion composition of snowflakes varies both temporally and with crystal habit.
Three-dimensional distribution of 3H-naloxone binding to opiate receptors in the human fetal and infant brainstem

Despite the putative role of opioids in disorders of the developing human brainstem, little is known about the distribution and ontogeny of opioid- specific perikarya, fibers, terminals, and/or receptors in human fetuses and infants. This study provides baseline information about the quantitative distribution of opiate receptors in the human fetal and infant brainstem. Brainstem sections were analyzed from three fetuses, 19-21 weeks gestation, and seven infants, 45-68 postconceptional weeks, in whom the postmortem interval was ≤12 hours. Opiate receptors were localized by autoradiographic methods with the radiolabelled antagonist 3H-naloxone. Computer-based methods permitted quantitation of 3H-naloxone binding in specific nuclei, as well as three-dimensional reconstructions of binding patterns. High 3H-naloxone binding corresponds primarily to sensory and limbic nuclei, and to nuclei whose functions are known to be influenced by opioids, e.g., trigeminal nucleus (pain), nucleus tractus solitarii and nucleus parabrachialis medialis (cardiorespiration), and locus coeruleus (arousal). The regional distribution of opiate receptors as determined by 3 H-naloxone binding is similar in human infants to that reported in human adults and animals and corresponds most closely to that of mu receptors. We found, however, that opiate receptor binding is high in the fetal and infant inferior olive, in comparison to low binding reported in this site in adult humans, primates, and rodents. In addition, opiate receptors are sparse in the fetal and infant substantia nigra, as in reports of the adult human substantia nigra, compared to moderate densities reported in primates and rodents. By midgestation, the regional distribution of 3 H-naloxone binding in human fetuses is similar, but not identical, to that in infants. Highest 3 H-naloxone binding occurs in the inferior olive in fetuses at midgestation, compared to the interpeduncular nucleus in infants. Tritiated naloxone binding quantitatively decreases in virtually all nuclei sampled over the last trimester, but not to the same degree. The most substantial binding decrease (two- to fourfold) occurs in the inferior olive and may reflect programmed regressive events, e.g., neuronal loss, during its development. Definitive developmental trends in 3 H-naloxone binding occurs in the inferior olive in fetuses at midgestation, compared to the interpeduncular nucleus in infants. Tritiated naloxone binding quantitatively decreases in virtually all nuclei sampled over the last trimester, but not to the same degree. The most substantial binding decrease (two to fourfold) occurs in the inferior olive and may reflect programmed regressive events, e.g., neuronal loss, during its development. Definitive developmental trends in 3H- naloxone binding are not observed in the postnatal period studied. The heterogeneous distribution of opiate binding in individual brainstem nuclei underscores the need for volumetric sampling in quantitative studies.
Reversible protein adsorption and bioadhesion on monolayers terminated with mixtures of oligo(ethylene glycol) and methyl groups.

Surface-grafted, environmentally responsive polymers have shown great promise for controlling adsorption and desorption of macromolecules and cells on solid surfaces. In the paper, we demonstrate that certain mixed self-assembled monolayers (SAMs) of oligo(ethylene glycol) (OEG) and methyl-terminated alkanethiolates on gold form surfaces with switchable hydrophobicity and tendency for protein adsorption and cellular attachment. At temperatures above 32 °C, SAMs with a surface density of ∼50% OEG adsorbed significant amounts of pyruvate kinase and lysozyme, whereas below this temperature, these same SAMs were resistant to the adsorption of these proteins. Furthermore, protein layers adsorbed to these SAMs above 32 °C were removed upon rinsing with water below this temperature. Similar results were seen for attachment and release of the marine bacterium, Cobetia marina. The change from nonresistance to adsorptive state of the SAMs was concomitant with a change in advancing water contact angle. Vibrational s...
The coupled climate system and global change

Current estimates of future global climate change rely on coupled models of the climate system. These models are both a measure of our level of understanding of coupled processes occurring in nature and of our ability to simulate the possible changes in these processes due to increased CO2 and trace gases with computer models. Central to coupled models is air-sea interaction, but processes involving the cryosphere, biosphere, atmospheric chemistry/radiation, and land surface are also intimately involved. Monitoring and analysis of observations are critical for understanding and interpreting results from the coupled models.
Risk of mortality after spinal cord injury: relationship with social support, education, and income.

Risk of mortality after spinal cord injury: relationship with social support, education, and income
Coincidence detection of heterogeneous cell populations from whole blood with coplanar electrodes in a microfluidic impedance cytometer

Particle counting finds many industrial applications especially in medical healthcare. In particular, cell counting from whole blood is used pervasively for disease diagnostics. Microfluidic impedance cytometry is fast, requires a small volume of blood, can be used at point of care and can perform absolute enumeration of different cell types in the sample. Coincidence detection is very essential for accurate counting results and becomes more significant while counting specific target cells, e.g. CD4+ or CD8+ T cell count in HIV/AIDS patient blood samples. In heterogeneous samples, e.g. blood, cell differentiation for all coincidence occurrences is essential in addition to the coincidence detection for accurate cell enumeration. In this paper, we have characterized the coincidence detection with cell differentiation using a microfluidic impedance biochip. The pure population of leukocytes is obtained after all erythrocytes are lysed on-chip from whole blood. Leukocytes were counted electrically as they pass over coplanar microfabricated electrodes bonded to the 15 μm × 15 μm cross section counting channel while generating a bipolar pulse for each cell passage. We have developed a mathematical model to simulate the electrical cell pulse and its coincidences. We show that coincidence detection can be characterized into three main types based on the range of time delay at which the coincidence occurs. We have also characterized cell differentiation for all the three coincidence types and show that multiple coincidences of different types can also occur. We used healthy and HIV-infected patient blood samples and used our coincidence detection technique to count CD4+ and CD8+ T cells and show the improvement in accuracy of cell counts compared to that without coincidence detection. We have also shown the improvement in the erythrocyte counting with coincidence detection in diluted whole blood samples.
Custom electron bolus treatment planning with skin collimation using the pencil-beam redefinition algorithm

ECT is defined as the use of one or more electron beams for the following purpose: (1) containing the planning target volume (PTV) in the 90% (of given dose) dose surface: (2) achieving as homogenous a dose as possible (e.g., 90% to 100%) or a prescribed heterogeneous dose distribution to the PTV; and (3) delivering a minimal dose to underlying critical structures and normal tissue [1]. ECT can be achieved through energy modulation Results cont. . The superior aspect of the patient plan using bolus ECT without skin collimation is illustrated in Figure 5. Due to the width of the beam penumbra and the proximity of the PTV to the eye, the lens and ocular orbit receive considerable dose compared to the plan with skin collimation in Figure 6. DVHs in Figure 7 show insignificant changes in the DVH of the PTV, but significant changes in the DVHs of the critical structures. For the lens, dose to the 10% volume is reduced from 24% (13 Gy) to 5% (3 Gy). For the ocular orbit, dose is reduced from
Hyperspectral imaging using a color camera and its application for pathogen detection

This paper reports the results of a feasibility study for the development of a hyperspectral image recovery (reconstruction) technique using a RGB color camera and regression analysis in order to detect and classify colonies of foodborne pathogens. The target bacterial pathogens were the six representative non-O157 Shiga-toxin producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) grown in Petri dishes of Rainbow agar. The purpose of the feasibility study was to evaluate whether a DSLR camera (Nikon D700) could be used to predict hyperspectral images in the wavelength range from 400 to 1,000 nm and even to predict the types of pathogens using a hyperspectral STEC classification algorithm that was previously developed. Unlike many other studies using color charts with known and noise-free spectra for training reconstruction models, this work used hyperspectral and color images, separately measured by a hyperspectral imaging spectrometer and the DSLR color camera. The color images were calibrated (i.e. normalized) to relative reflectance, subsampled and spatially registered to match with counterpart pixels in hyperspectral images that were also calibrated to relative reflectance. Polynomial multivariate least-squares regression (PMLR) was previously developed with simulated color images. In this study, partial least squares regression (PLSR) was also evaluated as a spectral recovery technique to minimize multicollinearity and overfitting. The two spectral recovery models (PMLR and PLSR) and their parameters were evaluated by cross-validation. The QR decomposition was used to find a numerically more stable solution of the regression equation. The preliminary results showed that PLSR was more effective especially with higher order polynomial regressions than PMLR. The best classification accuracy measured with an independent test set was about 90%. The results suggest the potential of cost-effective color imaging using hyperspectral image classification algorithms for rapidly differentiating pathogens in agar plates.