cssi/SciSciGPT-SciSciNet huggingface dataset:
Policy function scheduling

Abstract Scheduling disciplines have traditionally been specified in terms of a queue structure and algorithms for routing jobs within this structure. Alternatively, a discipline may be formally defined by a policy function, a function of job and system parameters. A policy function scheduler is a parameterized scheduler that — when supplied with a specific policy function — behaves like the specified discipline. The formal definition allows performance measures of a discipline (e.g., the response function) to be expressed in terms of the defining policy function. We review the principles of formal definitions, summarize previous queueing-theoretical results concerning response functions of policy function schedulers, and extend them to multiple preemptive job classes with processor-sharing subclasses. For a large variety of disciplines and job classes, we also express the policy functions in terms of the resulting response functions. Given a desired realizable performance goal, this relation serves to determine the discipline that achieves it. Policy function schedulers with their explicit relation between policy and response functions, which we plot for several different job characteristics, thus offer increased precision in controlling the performance of a computer system.
The ultrastructure of the rickettsia-like microorganism Wolbachia pipientis and associated virus-like bodies in the mosquito Culex pipiens.

Details of the ultrastructure of Wolbachia pipientis (Rickettsiales: Wolbachieae) from the ovaries and testes of autogenous Culex pipiens (Diptera: Culicidae) are described. Although similar to the rickettsia and certain insect symbionts, W. pipientis exhibits a peculiar form of cell division. Particles resembling Bradley's (Bacteriol. Rev. 31, 230, 1967) type C bacteriophage in size, with a nucleoid similar to herpesvirus, are frequently encountered in wolbachiae that appear to be lysing. Mature virus particles possess a toroidal nucleoid and may have a short tailpiece; they are polyhedral in shape.
PKD2 cation channel is required for directional sperm movement and male fertility.

Abstract Sperm of both mammals and invertebrates move toward specific sites in the female reproductive tract. However, molecular mechanisms for sperm to follow directional cues are unknown. Here, we report genetic analysis of Drosophila Pkd2 at 33E3 ( Pkd2 , CG6504 ), which encodes a Ca 2+ -activated, nonselective cation channel homologous to the human Pkd2 autosomal dominant polycystic kidney disease (ADPKD) gene [1]. The PKD2 family of genes has been implicated in sensory responses through protein localization on primary cilia of epithelia and neurons [2–4]. In renal tubules, cilium-associated PKD2 appears to mediate Ca 2+ influx in response to fluid flow, and the loss of fluid sensation probably contributes to cyst growth and ADPKD [4]. Sperm tails or flagella are specialized cilia essential for movement. Drosophila Pkd2 is abundantly associated with the tail and the acrosome-containing head region of mature sperm. Targeted disruption of Pkd2 results in male sterility without affecting spermatogenesis. The mutant sperm are motile but fail to swim into the storage organs in the female. Rare mutant sperm that reach the storage organs are able to fertilize the egg and produce viable progeny. Our data demonstrate that the Drosophila PKD2 cation channel operates in sperm for directional movement inside the female reproductive tract.
Measurement of Diffusion Coefficients Important in Modeling the Absorption Rate of Carbon Dioxide into Aqueous N-Methyldiethanolamine

Absorption rates of gaseous CO2 into aqueous N-methyldiethanolamine (MDEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of CO2 in solution but very sensitive to the diffusion rate of bicarbonate and protonated MDEA ions. Evidence also suggested that chemical reaction equilibrium is rapid relative to diffusion. A numerical model was developed on the basis of these observations. The model was used to regress diffusion coefficients of bicarbonate and protonated amine, which must be equivalent by electroneutrality arguments, from measured absorption rates. Complete modeling of the absorption process also required data for the diffusion coefficient of MDEA in water. These were measured using a Taylor dispersion apparatus. CO2 absorption rates and diffusion coefficients of bicarbonate and protonated MDEA were obtained at 298.2 K and 318.2 K in solutions containing 20, 35, ...
CHEMOSENSORY CAPABILITIES IN THE PHAGOTROPHIC DINOFLAGELLATE GYMNODINIUM FUNGIFORME11

The non-photosynthetic, phagotrophic dinoflagellate, Gymnodinium fungiforme Anissimova is attracted to a variety of amino acids and other organic compounds. Glycine, taurine and serine attracted the dinoflagellates at a threshold detection level of 10−8 M fallowed by dextrose (10−7 M) and alanine, proline and threonine (10−6 M). Glycine, taurine and alanine are three of the most abundant free amino acids found in invertebrates and protozoa which are major food sources of this dinoflagellate. Three additional species of cultured heterotrophic dinoflagellates were exposed to the water soluble fraction of a shrimp extract known to attract G. fungiforme. All three species responded to the extract, but one species, Oxyrrhis marina, did so only after changing its food source. It is suggested that chemosensory behavior may be suppressed or expressed depending on culture conditions.
Should scientific journals be printed? A personal view

Although the widely appreciated advantages of electronic journals in the sciences would indicate that they should be the preferred form of publication, they persist in print as well. The data on the relative use of bound and unbound journals in an academic biology library suggest that almost all of the journals studied are suitable as electronic only; only a very few are reasonable choices in both print and electronic formats. Most scientific articles might be better suited for publication not in journals at all, but rather in a suitable Internet‐based repository.
The Mechanism of Polymerization of Butadiene by “Ligand-Free” Nickel(II) Complexes

The polymerization of 1,3-dienes has been well-studied using an array of metal-containing complexes. Although a variety of (π-allyl) Ni(II) catalysts have been shown to be active for diene polymeri...
Not all insertion methods yield constant approximate tours in the Euclidean plane

Abstract An insertion heuristic for the traveling salesman problem adds cities iteratively to an existing tour by replacing one edge with a two-edge path through the new city in the cheapest possible way. Rosenkrantz (1977) asked whether every order of inserting vertices gives a constant-factor approximation algorithm. We answer this question by showing that for some point sets, there is an order that yields tours with length Ω( log n⧸ log log n) times optimum, even if the underlying metric space is the Euclidean plane.
Social work education and Title IV-E program participation as predictors of entry-level knowledge among public child welfare workers

Abstract Given the resources expended in promoting social work education and specialized training in child welfare as a means to increase the knowledge and competency of public child welfare (PCW) workers, research in this area is important to evaluate the outcomes of such efforts. The current study adds to the literature in this area by examining the performance of newly-hired PCW workers on objective tests of child welfare-related knowledge. Workers with Master of Social Work (MSW) degrees were compared to those with other degrees to examine whether there were differences in performance by social work education on an overall test of knowledge and two tests assessing for specific knowledge areas. The study also examined whether participation in Title IV-E stipend-based programs was a factor in test performance among only those workers who had MSW degrees. The findings supported the hypothesis that workers with MSW degrees would score higher on all measures when compared to those with other degrees. The results also supported the hypothesis that workers with MSW degrees who participated in Title IV-E programs would score higher than those with MSW degrees who did not participate in such programs. Implications for the PCW field and future research in this area are discussed.
The spatial and temporal structure of thermal fluctuations associated with a vertical turbulent jet impinging a water surface: laboratory experiments and field observations

Infrared imaging, in both laboratory and field settings, has become a vital tool in diagnosing near-surface thermalhydrodynamic phenomena such as convective cells, accumulation of surfactant, and coherent turbulent structures. In this presentation, we initially focus on a laboratory scale (0.01-1m) subsurface vertical turbulent water jet that serves as a canonical flow. The jet has a slightly elevated temperature thus the warmer fluid serves as a passive marker. Infrared image sequences of the surface thermal field were collected for various water jet flow rates and for both "clean" and surfactant-contaminated surface conditions. Turbulent characteristics of the near-surface flow field were measured by means of Digital Particle Image Velocimetry (DPIV), and these are used to examine the statistical nature of the coupled thermal-hydrodynamic field. An analog of the laboratory jet is the discharge of power-plant cooling water through a vertical pipe on the ocean floor. High-resolution airborne infrared imagery has recently been acquired of such a discharge (from the Huntington Beach Generating Station, CA), and these data are compared with the laboratory results in an attempt to understand striking spatial patterns discovered on the ocean surface.
Polarization properties of Maxwell-Gaussian laser beams.

Gaussian beam solutions of Maxwell's equations are constructed in terms of the solutions of the paraxial scalar wave equation. Explicit expressions for the field components of Hermite-Gaussian laser beams are given and their polarization and propagation characteristics are discussed. Experimental evidence for the polarization structure of Hermite-Gaussian laser beams is presented.
AUTOMATED KNOWLEDGE ACQUISITION FROM ENCYCLOPEDIC TEXTS

A computational model for the acquisition of knowledge from encyclopedic texts is described. The model has been implemented in a program, called SNOWY, that reads unedited texts from The World Book Encyclopedia, and acquires new concepts and conceptual relations about topics dealing with the dietary habits of animals, their classifications and habitats. The program is also able to answer an ample set of questions about the knowledge that it has acquired. This paper describes the essential components of this model, namely semantic interpretation, inferences and representation, and ends with an evaluation of the performance of the program, a sample of the questions that it is able to answer, and its relation to other programs of similar nature.
AMP-activated protein kinase phosphorylation in brain is dependent on method of killing and tissue preparation.

AMP-activated protein kinase is activated when the catalytic α subunit is phosphorylated on Thr172 and therefore, phosphorylation of the α subunit is used as a measure of activation. However, measurement of α-AMP-activated protein kinase phosphorylation in vivo can be technically challenging. To determine the most accurate method for measuring α-AMP-activated protein kinase phosphorylation in the mouse brain, we compared different methods of sacrifice and tissue preparation. We found that freeze/thawing samples after homogenization on ice dramatically increased α-AMP-activated protein kinase phosphorylation in mice sacrificed by cervical dislocation. Sacrifice of mice by focused microwave irradiation, which rapidly heats the brain and causes enzymatic inactivation, prevented the freeze/thaw-induced increase in α-AMP-activated protein kinase phosphorylation and similar levels of phosphorylation were observed compared to mice sacrificed with cervical dislocation without freeze/thawing of samples. Sonication of samples in hot 1% sodium dodecyl sulfate blocked the freeze/thaw-induced increase in α-AMP-activated protein kinase phosphorylation, but phosphorylation was higher in mice sacrificed by cervical dislocation compared to mice sacrificed by focused microwave irradiation. These results demonstrate that α-AMP-activated protein kinase phosphorylation is dependent on method of sacrifice and tissue preparation and that α-AMP-activated protein kinase phosphorylation can increase in a manner that does not reflect biological alterations.
Effect of crosslinking cytochrome c oxidase.

Abstract Bovine heart cytochrome c oxidase and rat liver mitochondria were crosslinked in the presence and absence of cytochrome c . Biimidate treatment of purified cytochrome oxidase, which results in the crosslinkage of all of the oxidase protomers except subunit I when ⩾ 20% of the free amines are modified, inhibits ascorbate- N,N,N′,N′ -tetramethyl- p -phenylene diamine oxidase activity. Intermolecular crosslinking of cytochrome oxidase molecules, which results in the formation of large enzyme aggregates displaying rotational correlation times ⩾ 1 ms, does not affect oxidase activity. Crosslinking of mitochondria covalently binds the cytochrome bc 1 and aa 3 complexes to cytochrome c , and inhibits steady-state oxidase activity. Addition of cytochrome c to purified cytochrome oxidase or to cytochrome c -depleted mitoplasts increases this inhibition slightly. Cytochrome c oligomers act as competitive inhibitors of native cytochrome c ; however, crosslinking of cytochrome c to cytochrome c -depleted mitoplasts or purified cytochrome oxidase results in a catalytically inactive complex. These experiments indicate that cytochrome c oxidase subunit interactions are required for activity, and that cytochrome c mobility may be essential for electron transport between cytochrome c reductase and oxidase.
The T cell activation marker CD150 can be used to identify alloantigen-activated CD4+25+ regulatory T cells

We have been investigating whether alloantigen-specific CD4(+)25+ regulatory T cells can be identified for use in treating graft-versus-host disease. CD150, which is upregulated on the surface of all activated T lymphocytes, was identified as a candidate marker for alloantigen-activated CD4(+)25+ regulatory T cells by gene chip analysis. Freshly isolated CD4(+)25+ cells had only low cell-surface expression of CD150, comparable to that of CD4(+)25- T cells. Increased CD150 expression was observed on all T cells after coculture with allogeneic stimulator cells. When purified CD4(+)25+ cells were precultured with allogeneic stimulator cells, then sorted into CD150+ and CD150- subsets, allosuppressive activity was contained primarily in the CD150+ fraction. These cells also suppressed the proliferation of alloantigen-activated autologous T cells, and they could be expanded in vitro without loss of their suppressive capacity. These results suggest that CD150 can be used as a marker for the identification of purified alloantigen-activated CD4(+)25+ regulatory T cells.
Well-point sampling of reef interstitial water

A technique is described for collecting reef interstitial water using manually-driven well points. This method does not require the use of hydraulic drills, and eliminates the problems associated with the casing of boreholes. The technique allows collection of samples from discrete depths within reef frameworks, and produces samples unaffected by atmospheric or surface seawater contamination. Data from Checker Reef, Oahu, Hawaii illustrate the utility of this approach.
Tooth Whitening Today

ABSTRACT Background Methods to improve the esthetics of the dentition by tooth whitening are of interest to dentists, their patients and the public. In the past 20 years, research on bleaching and other methods of removing tooth discolorations has dramatically increased. Dentist-supervised and over-the-counter products now are available to solve a variety of tooth discoloration problems without restorative intervention. The indications for appropriate use of tooth-whitening methods and products are dependent on correct diagnosis of the discoloration. Overview Tooth-whitening methods include the use of peroxide bleaching agents to remove internal discolorations or abrasive products to remove external stains. Peroxide bleaching procedures are completed by the dentist in single or multiple appointments, or by the patient over a period of weeks to months using custom trays loaded with a bleaching agent. Both methods are safe and effective when supervised by the dentist. Microabrasion is indicated for the removal of isolated discolorations that often are associated with fluorosis. Whitening toothpastes remove surface stains only through the polishing effect of the abrasives they contain. Conclusions and Practice Implications Tooth whitening is a form of dental treatment and should be completed as part of a comprehensive treatment plan developed by a dentist after an oral examination. When used appropriately, tooth-whitening methods are safe and effective.
Remifentanil versus alfentanil in a balanced anesthetic technique for total abdominal hysterectomy

Study objectives To compare the intraoperative effects and recovery characteristics of remifentanil hydrochloride and alfentanil when administered as part of balanced anesthesia, and to assess the effects of an additional remifentanil infusion administered as analgesic pretreatment before removal of the uterus. Design Multicenter, double-blind, randomized, parallel-group study. Setting Two university hospitals. Patients 35 ASA physical status I, II, and III women scheduled for elective total abdominal hysterectomy with general endotracheal anesthesia. Interventions Patients were premedicated with midazolam 0.05 mg/kg intravenously (i.v.). Anesthesia was induced with thiopental 2 mg/kg, vecuronium 0.15 mg/kg, and a single dose of opioid over 60 seconds (Pump 1): remifentanil 2 micrograms/kg (Remi/Placebo and Remi/Remi groups) or alfentanil 50 micrograms/kg (Alf/Placebo group). Anesthesia was maintained with a nitrous oxide/oxygen mixture (66:34 ratio) and a continuous opioid infusion: remifentanil 0.25 microgram/kg/min (Remi/Placebo and Remi/Remi) or alfentanil 0.5 microgram/kg/min (Alf/Placebo). At skin incision, a second blinded drug infusion was also initiated (Pump 2): remifentanil 0.25 microgram/kg/min (Remi/Remi) or saline placebo (Remi/Placebo and Alf/Placebo). Intraoperative responses were controlled with single doses of opioid and/or rate titrations via Pump 1. Pump 2 was terminated on removal of the uterus. Pump 1 was terminated at skin closure. Measurements and main results The mean (+/- SD) opioid infusion rates administered for the duration of Pump 2 to suppress responses to removal of the uterus were 0.49 +/- 0.27 microgram/kg/min, 1.99 +/- 1.34 micrograms/kg/min, and 0.49 +/- 0.07 microgram/kg/min for the Remi/Placebo, Alf/Placebo, and Remi/Remi groups, respectively. At these rates, similar proportions of patients in the Remi/Placebo (67%) and the Alf/Placebo (60%) groups had responses. Fewer patients had responses in the Remi/Remi group (8%) compared with the Remi/Placebo and Alf/Placebo groups (p Conclusions A mean remifentanil infusion of 0.49 microgram/kg/min is as effective as a mean alfentanil infusion of 1.99 micrograms/kg/min in suppressing intraoperative responses. Doubling of the remifentanil infusion to 0.5 microgram/kg/min before the major stress event improves suppression of responses and lowers intraoperative use of remifentanil without prolonging recovery times. Remifentanil allows faster awakening times than alfentanil, but preemptive administration of postoperative analgesics is recommended to facilitate discharge.
External organizational commitment

Abstract Building on the organizational commitment literature and recent management practices like relationship marketing and total quality management, a new focus of work commitment is proposed: external organizational commitment (EOC). It is envisioned as a global construct and defined as an employee's identification and involvement with another organization. A model of EOC specifying its antecedents, consequences, and moderating factors is offered and 28 propositions emanating from the model are articulated. Implications for human resource practitioners are discussed.
Ubiquitin Transfer from the E2 Perspective: Why is UbcH5 So Promiscuous?

Protein ubiquitination is a regulatory process that influences nearly every aspect of eukaryotic cell biology. Pathways that range from cell-cycle progression and differentiation to DNA repair to vesicle budding all rely on regulated modification of target proteins by ubiquitin. Target proteins can be tagged by a single molecule of ubiquitin or modified by ubiquitin polymers that can vary in length and linkage specificity, and these variations influence how ubiquitination signals are interpreted. Surprisingly, little is understood regarding mechanisms of protein ubiquitination and how poly-ubiquitin chains are synthesized. Simple models to explain ubiquitin transfer have dominated the literature, but recent work suggests basic assumptions as to how proteins assemble to facilitate protein ubiquitination and poly-ubiquitin chain synthesis should be reexamined. This is particularly necessary for understanding the roles played by E2 ubiquitin-conjugating enzymes, a central protein component in all ubiquitin transfer reactions. In particular, UbcH5, a canonical E2 protein that is active in a broad number of in vitro ubiquitin transfer reactions, is capable of binding ubiquitin noncovalently on a surface distinct from its active site. This unique property allows activated UbcH5 approximately Ub complexes to self-assemble and has a profound influence on poly-ubiquitin chain synthesis.
Use of Public Health Nursing Services: Relationship to Adequacy of Prenatal Care and Infant Outcome

Timing of initial public health nurse contact and number of nurse contacts were examined for their relationship to adequacy of prenatal physician care, infant birthweight, and gestational age. Three historical cohort groups were drawn from three downstate Illinois counties: 1) public health nursing clients (N = 506); 2) Women, Infant, and Children Nutrition Program clients (N = 314); and 3) clients receiving neither of these services (N = 403). Data were obtained from local health department records and a state birth certificate data tape. Descriptive statistics and logistic and multiple regression were used to analyze data. Timing of initial public health nursing contact was significantly correlated to adequacy of prenatal physician contact and infant gestational age. No relationship was found between either timing of initial public health nursing contact or number of these contacts and infant birthweight. The number of public health nursing and physician contacts exerted an additive effect on birthweight and gestational age. Findings lend support for case-finding activities that result in public health nursing contacts early in pregnancy. The importance of multidisciplinary approaches to prenatal care is suggested.
Cholesterol Exchange and Lateral Cholesterol Pools in Synaptosomal Membranes of Pair‐Fed Control and Chronic Ethanol‐Treated Mice

Most studies on effects of ethanol on membrane cholesterol have reported on changes in the total or bulk amount of cholesterol. Membrane cholesterol, however, can be described in terms of its kinetics and domains. The kinetics and size of lateral cholesterol exchangeable and nonexchangeable pools were examined in synaptosomes of pair-fed controls and chronic ethanol-treated mice. Effects of sphingomyelin, an exofacial leaflet phospholipid, that has been shown to affect cholesterol pools, were also examined. Radiolabeled small unilamellar vesicles were used to exchange cholesterol with synaptosomes. The total amounts of membrane cholesterol, phospholipid phosphorus, and the ratio of cholesterol to phospholipid did not differ between the pair-fed control and ethanol groups. In control mice, the rate constant (hr-1) and the t1/2 (hr) of cholesterol exchange were 0.065 ± 0.001 and 10.7 ± 0.25 (hr), respectively. The rate constant was significantly slower (0.053 ± 0.001, p < 0.05) and the t1/2 significantly longer (13.33 ± 0.58, p < 0.05) in synaptosomes of the ethanol group compared with the control group. The size of the exchangeable pool of cholesterol did not differ significantly between the two groups. Sphingomyelinase-induced hydrolysis of sphingomyelin significantly slowed cholesterol exchange with the largest effect in synaptosomes of the control group as compared with the ethanol group (p < 0.05). Hydrolysis of sphingomyelin had significantly (p < 0.05) less of an effect on cholesterol exchange in synaptosomes of the ethanol group. Membrane cholesterol can be described in terms of total content, transbilayer distribution, kinetics, and size of lateral pools. This study supports the general hypothesis, that not all properties or domains of membrane cholesterol are equally affected by ethanol.
Generation of internal lee waves trapped over a tall isolated seamount

Abstract A primitive equation numerical model is used to study the generation of internal lee waves in a steady, rotating, uniformly stratified flow past an isolated seamount. We find that large-amplitude internal lee waves can form over the seamount even when the imposed steady flow is too weak to support the internal lee waves away from the seamount (i.e. low Froude and Rossby numbers). These internal lee waves are trapped over the flank of the seamount where nonlinear advection of momentum leads to a large local acceleration of the flow. As the flow decelerates downstream of the seamount, the internal lee wave amplitude and wavelength are reduced to the point where parameterized subgridscale mixing quickly dissipates the waves. This contrasts with the traditional case of internal lee waves in rapid background flows where the local acceleration over the seamount is relatively unimportant and the waves continue well downstream of the seamount. The model results also indicate that the trapped internal lee...
Thermostable uracil-DNA glycosylase from Thermotoga maritima a member of a novel class of DNA repair enzymes

Abstract Uracil-DNA glycosylase (UDG) is a ubiquitous enzyme found in eukaryotes and prokaryotes [1–3]. This enzyme removes uracil bases that are present in DNA as a result of either deamination of cytosine or misincorporation of dUMP instead of dTMP [4,5], and it is the primary activity in the DNA base excision repair pathway. Although UDG activities have been shown to be present in several thermophiles [6–8], no sequences have been found that are complementary to the Escherichia coli ung gene, which encodes UDG [9]. Here, we describe a UDG from the thermophile Thermotoga maritima . The T. maritima UDG gene has a low level of homology to the E. coli G–T/U mismatch-specific DNA glycosylase gene ( mug ). The expressed protein is capable of removing uracil from DNA containing either a U–A or a U–G base pair and is heat-stable up to 75°C. The enzyme is also active on single-stranded DNA containing uracil. Analogous genes appear to be present in several prokaryotic organisms, including thermophilic and mesophilic eubacteria as well as archaebacteria, the human-disease pathogens Treponema palladium and Rickettsia prowazekii , and the extremely radioresistant organism Deinococcus radiodurans . These findings suggest that the T. maritima UDG is a member of a new class of DNA repair enzymes.
Adaptive Mutations in the JC Virus Protein Capsid Are Associated with Progressive Multifocal Leukoencephalopathy (PML)

PML is a progressive and mostly fatal demyelinating disease caused by JC virus infection and destruction of infected oligodendrocytes in multiple brain foci of susceptible individuals. While JC virus is highly prevalent in the human population, PML is a rare disease that exclusively afflicts only a small percentage of immunocompromised individuals including those affected by HIV (AIDS) or immunosuppressive drugs. Viral- and/or host-specific factors, and not simply immune status, must be at play to account for the very large discrepancy between viral prevalence and low disease incidence. Here, we show that several amino acids on the surface of the JC virus capsid protein VP1 display accelerated evolution in viral sequences isolated from PML patients but not in sequences isolated from healthy subjects. We provide strong evidence that at least some of these mutations are involved in binding of sialic acid, a known receptor for the JC virus. Using statistical methods of molecular evolution, we performed a comprehensive analysis of JC virus VP1 sequences isolated from 55 PML patients and 253 sequences isolated from the urine of healthy individuals and found that a subset of amino acids found exclusively among PML VP1 sequences is acquired via adaptive evolution. By modeling of the 3-D structure of the JC virus capsid, we showed that these residues are located within the sialic acid binding site, a JC virus receptor for cell infection. Finally, we go on to demonstrate the involvement of some of these sites in receptor binding by demonstrating a profound reduction in hemagglutination properties of viral-like particles made of the VP1 protein carrying these mutations. Collectively, these results suggest that a more virulent PML causing phenotype of JC virus is acquired via adaptive evolution that changes viral specificity for its cellular receptor(s).
A Prototype Digital Tomographic X-Ray System For Dental Applications

This report describes a prototype dental x-ray machine designed to eliminate shortcomings of conventional dental radiographic methods by using multiple image sampling techniques, electronic x-ray detection, and computer image processing. A miniaturized intraoral x-ray tube is used having an enlarged target on which multiple focal spots can be excited sequentially under computer control. The detector is a video-based image intensifier yielding a sequence of projections which are stored digitally in real time. Suitable processing of these images permits synthesis of tomographic slices. Specific projections obtained at different examinations can be matched so that subsequent subtraction demonstrates diagnostically important changes.
Relation between needle electromyography and nerve conduction studies in patients with carpal tunnel syndrome

Four hundred eighty cases of electrodiagnostically confirmed carpal tunnel syndrome were reviewed to determine if the findings on nerve conduction studies could predict the presence or absence of fibrillation potentials or motor unit changes on the needle examination of the abductor pollicis brevis (APB). The needle examination is more uncomfortable and the ability to predict the findings in this setting from standard nerve conduction studies (NCS) would make the test more acceptable to patients. All patients had median and ulnar nerves (both sensory and motor) tested, as well as the needle evaluation of the APB. Two hundred thirty-one patients had an abnormal needle evaluation as defined by presence of one of the following conditions: abnormal spontaneous activity, increased motor unit action potential (MUAP) amplitude, or increased MUAP polyphasia. One hundred five patients had fibrillation potentials. The mean median motor and sensory amplitudes and latencies, as well as age, did differ in the normal and abnormal needle examination groups, but the sensitivity for predicting an abnormality ranged from 57% to 68%. The ratio of the median to the ulnar amplitudes did not improve the sensitivity of predicting the abnormal needle findings. Motor and sensory evoked potential latencies were the most important predictors of an abnormal needle examination.
Effect of Hydroxyurea in Children With Sickle Cell Disease in Saudi Arabia

Abstract Objective The objective of this study is to demonstrate the effects of hydroxyurea in children with sickle cell disease at Madina Maternity and Children's Hospital and to evaluate its short term safety. Methods This was a retrospective review over two years period from 2004–2006. The inclusion criteria were: 1. Children with sickle cell disease who had three or more attacks of painful crisis per year 2. Children with sickle cell disease who had two or more episodes of acute chest syndrome per year. The dose range of Hydroxyurea was 15–30 mg/kg/day. The clinical episodes and the laboratory investigations were monitored monthly. Results The total patients included initially were 14; 4 patients were excluded because of poor compliance to treatment. 10 patients were eligible for the study. 6 were male and 4 were female. 8 patients were Saudi and 2 patients were non Saudis. The age range was 5–15 years. The attacks of painful crisis and acute chest syndrome were significantly reduced after Hydroxyurea treatment, also laboratory investigation showed significant increase in MCV and Hemoglobin F values after Hydroxyurea. Conclusion We conclude that Hydroxyurea is effective in children with sickle cell disease and had no major short term adverse effect. However long terms follow up is required to evaluate long term adverse effect.
Minoxidil overdose with ecg changes: Case report and review

A 20-year-old female ingested an unknown quantity of minoxidil tablets as a suicide gesture. She presented to the emergency department about 90 minutes later with tachycardia, diffuse T wave inversion, and S-T segment depression on the ECG, labile hypotension, and a substantially elevated total serum minoxidil concentration of 3140 ng/mL. She responded to supportive therapy with intravenous fluids, and was discharged 32 hours later with stable blood pressure and mild residual tachycardia. The clinical toxicology, treatment, and previous case reports of minoxidil overdose are reviewed.
Interference management schemes for the shared relay concept

Sharing a multiantenna relay among several sectors is a simple and cost-effective way to achieving much of the gains of local interference mitigation in cellular networks. Next generation wireless systems, such as ones based on the Third Generation Partnership Projects Long-Term Evolution Advanced, will employ universal frequency reuse to simplify network deployment. This strategy is anticipated to create significant cell-edge interference in the location of the shared relays, thus rendering advanced interference management strategies a necessity. This paper proposes several interference management strategies for the shared relays ranging from simple channel inversion at the relay, to more sophisticated techniques based on channel inversion in combination with partial and full base station coordination in the downlink and uplink. Given that the relay functionality influences total interference, both amplify-and-forward and decode-and-forward type relays are considered throughout. In this context, channel cancelation techniques are investigated for one-way relaying and also the spectrally efficient two-way relaying protocol. Simulations show that strategies based on two-way shared relaying with bidirectional channel inversion at the relay often perform best in terms of total system throughput while one-way techniques are promising when the relay power is low.
An Examination of Factors Associated with User Acceptance of Social Shopping Websites

Social commerce is the latest development in e-commerce to combine the power of online social networking with shopping. While the adoption of information technology is well studied, new theoretical development is needed to account for the specific characteristics of social commerce applications and their interactions with the user. This study examines factors that are associated with user acceptance of social shopping websites, which are sites designed specifically to support social interactions while users shop. This paper augments the Technology Acceptance Model with constructs that enhance the specificity of the model to the social shopping application of social commerce, including social comparison, social engagement, enjoyment as well as perceived ease of use and perceived usefulness. The model was empirically tested, and the results provided strong support. Implications and directions for future research are also discussed.
PRODUCTS OF ACTIVATED LYMPHOCYTES I. THE USE OF RADIOLABELING TECHNIQUES IN THE CHARACTERIZATION AND PARTIAL PURIFICATION OF THE MIGRATION INHIBITORY FACTOR OF THE GUINEA PIG

General methods were developed and applied to the biosynthesis and purification of products of activated lymphocytes available in minute quantities. The activity studied here was the migration inhibitory factor (MIF) produced by purified protein derivative (PPD)- or concanavalin A (Con A)-stimulated lymphocytes obtained from one guinea pig or less. The methods selected yielded results in terms of two chemical parameters characteristic of the molecules involved, namely Kd on Sephadex G-75 and isoionic point, pI, on isoelectric focusing. When supernatants were fractionated on G-75 columns, there were several areas even in control supernatants which produced migration inhibition relative to medium controls. However, in PPD- and Con A-stimulated supernatants, at least one peak of MIF activity was found solely in the stimulated cultures, with a Kd of 0.15. A double-labeling technique was used to characterize the proteins of this peak. Control, unstimulated cultures were labeled with [14C]leucine and stimulated cultures were labeled with [3H]leucine. After mixing the supernatants and G-75 filtration, a major "ratiolabeled" broad peak. i.e. one with increased 3H/14C ratio, was found. When a narrow portion of this peak about Kd 0.15, containing most of the MIF activity, was subjected to analytical isoelectric focusing, all of the label was associated with proteins of lower net charge than albumin. A unique ratiolabeled peak was found in PPD- and Con A-stimulated fractions with a pI of approx. 5.3. A micropreparative isoelectric focusing technique was developed and yielded MIF activity in the same region as the major ratiolabeled peak. Further study will be required to ascertain whether the ratiolabeled protein is MIF. By following the Kd, pI, and 3H/14C labeling ratio, at least 14 products of activated lymphocytes, synthesized either de novo or in increased amounts, could be distinguished.
Neonatal GATA1 mutant clones under the radar

In this issue of Blood , Roberts et al report the comprehensive screening of a large cohort of Down syndrome neonates for the transient abnormal myelopoiesis (TAM) disorder based on blood cell morphology review and screening for GATA1 mutations, the signature genetic marker of TAM.[1][1] ![Figure][
Target volume dose considerations in proton beam treatment planning for lung tumors.

We performed a treatment planning study in order to gather basic insight in the effect of setup errors and breathing motion on the cumulative protondose to a lungtumor. We used a simplified geometry that simulates a 50 mm diameter gross tumor volume (GTV) located centrally inside lungtissue. The GTV was expanded with a uniform 5 mm margin into a clinical target volume (CTV) and into a variety of planning target volume (PTV’s). Proton beam apertures were designed to conform the prescribed dose laterally to the PTV while the range compensator was designed to provide distal coverage of the CTV. Different smearing distances were applied to the range compensators, and the cumulative dose in the CTV was evaluated for different combinations of breathing motion and systematic setup errors. Evaluation parameters were the dose to 99% of the CTV ( D 99 ) and the equivalent uniform dose (EUD), with a surviving fraction at 2 Gy of S F 2 = 0.5 . For a single proton field designed to a 15 mm expansion of the CTV and without smearing applied to the range compensator, D 99 of the CTV reduced from 96% for no tumor displacement to 41% and 13% for systematic setup errors of 5 and 10 mm , respectively. For a representative clinical combination, of 5 mm systematic error and 10 mm breathing amplitude, the EUD of the CTV was about 40 Gy (prescribed dose 70 Gy ) regardless the CTV to PTV margin, and without smearing. Smearing the range compensator increases the dose to the CTV substantially with a lateral margin and smearing distance of 7.5 mm providing ample tumor coverage. In this latter case, D 99 of the target volume increased to 87% for a single field treatment plan. Smearing does, however, lead to an increase in dose to normal tissues distal to the clinical target volume. Next to countering geometric mismatches due to patient setup, smearing can also be used to counter the detrimental effects of breathing motion on the dose to the clinical target volume. We show that the lateral margin and smearing distance can be substantially smaller than the maximum tumor displacement due to setup errors and patient breathing, as measured by the D 99 and the EUD.
Architecture and Design for Virtual Conferences: A Case Study

This paper presents a case study of the design issues facing a large multi-format virtual conference. The conference took place twice in two different years, each time using an avatar-based 3D world with spatialized audio including keynote, poster and social sessions. Between year 1 and 2, major adjustments were made to the architecture and design of the space, leading to improvement in the nature of interaction between the participants. While virtual meetings will likely never supplant the effectiveness of face-to-face meetings, this paper seeks to outline a few design principles learned from this experience, which can be applied generally to make computer mediated collaboration more effective.
Emergent dynamics in a model of visual cortex

This paper proposes that the network dynamics of the mammalian visual cortex are highly structured and strongly shaped by temporally localized barrages of excitatory and inhibitory firing we call `multiple-firing events' (MFEs). Our proposal is based on careful study of a network of spiking neurons built to reflect the coarse physiology of a small patch of layer 2/3 of V1. When appropriately benchmarked this network is capable of reproducing the qualitative features of a range of phenomena observed in the real visual cortex, including spontaneous background patterns, orientation-specific responses, surround suppression and gamma-band oscillations. Detailed investigation into the relevant regimes reveals causal relationships among dynamical events driven by a strong competition between the excitatory and inhibitory populations. It suggests that along with firing rates, MFE characteristics can be a powerful signature of a regime. Testable predictions based on model observations and dynamical analysis are proposed.
Cool-season annual pastures with clovers to supplement wintering beef cows nursing calves

In December of 3 years, 87 beef cows with nursing calves (594 ± 9.8 kg; calving season, September to November) at side were stratified by body condition score, body weight, cow age, and calf gender and divided randomly into 6 groups assigned to 1 of 6 cool-season annual pastures (0.45 ha/cow) that had been interseeded into a dormant common bermudagrass (Cynodon dactylon [L.] Pers.)/bahiagrass (Paspalum notatum Flugge) sod. Pastures contained 1 of the following 3 seeding mixtures (2 pastures/mixture): 1) wheat (Triticum aestivum L.) and ryegrass (Lolium multiflorum Lam., WRG), 2) wheat and ryegrass plus red clover (Trifolium pretense L., WRR), or 3) wheat and ryegrass plus white (Trifolium repens L.) and crimson clovers (Trifolium incarnatum L., WRW). All groups had ad libitum access to grass hay (12% crude protein; 58% total digestible nutrients). The second week in December, cow estrous cycles were synchronized and artificially inseminated. In late December, a bull was placed with each group for 60-d. Data were analyzed with an analysis of variance using a mixed model containing treatment as the fixed effect and year as the random effect. Body weight and condition scores did not differ (P ≥ 0.27) among cows between February and June. Calf birth weights or average daily gain did not differ (P ≥ 0.17) among treatments; however, calves grazing pastures with clovers did tend (P = 0.06) to weigh more than calves grazing grass only. Weaning weight per cow exposed to a bull was greater (P = 0.02) for WRR and WRW than WRG. Cows grazing winter-annual pastures containing clovers tended to wean more calf body weight per cow exposed to a bull than cows grazing the grass only pastures.
Cooperative multi-agent inference over grid structured Markov random fields

In this work we investigate cooperative inference in multi-agent systems where uncertainty is modeled by the grid structured pairwise Markov random field. A framework is proposed, which we term the multi-agent Markov random field, that decomposes the global inference problem into inter-agent belief exchanges over a hypertree topology and local intra-agent inference problems. Due to the exponential complexity of exact inference, we propose a loopy belief propagation algorithm for approximate inference over appropriately formed local generalized cluster graphs. Both synchronous and intelligent message passing are considered and a grid scale-invariant scheme based on the notion of regions of influence in a cluster graph is presented. The algorithms are simulated over a grid workspace with a team of virtual Autonomous Surface Vehicles (ASVs), with the goal of spatial plume detection in oceanographic data captured from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. We show that while the exact method produces predictably accurate and smooth grid maps, the approximate method competes well in terms of plume detection rate with the region of influence message passing scheme excelling over large tasks due to a lack of dependence on grid size.
Aspects of Distance Sensitive Design of Wireless Sensor Networks

Distance sensitivity is a locality concept that is useful for designing scalable wireless sensor network applications. In this paper, we formally define distance sensitivity and we highlight its different forms such as distance sensitive latency, error, rate, membership, and healing. We show how distance sensitivity allows the application requirements and the network specification to be stated (and reasoned about) purely in geometric terms. This paper also examines key aspects of the concept, namely sufficiency, decomposability, and robustness. Specifically, sufficiency involves consideration of whether distance sensitive properties are enough for meeting application requirements. Decomposability involves choosing properties of network layers/components so that together the distance sensitive network abstraction holds. And, robustness implies preservation of distance sensitivity in the presence of failures in the network, including both permanent and transient failures and even those that violate the density or geometric assumptions of the network. We illustrate these aspects via examples from our previous work, all in the context of a common case study, regarding the design of a distributed pursuer evader tracking application.
An Unusual Cause of Posterior Tibial Tendon Degeneration

A case demonstrating a mechanical cause of posterior tibial tendon degeneration is reported. The possible etiologies for degeneration of the posterior tibial tendon are discussed.
Genetic and enzymatic characterization of a conditional lethal mutant of Escherichia coli K12 with a temperature-sensitive DNA ligase.

TAUts7 an Escherichia coli 15 strain with a thermolabile DNA ligase, has previously been shown to be a temperature-sensitive conditional lethal mutant that is sensitive to methyl methane sulfonate and to ultraviolet irradiation; it also accumulates 10 S DNA fragments to an abnormal extent. When the ligase mutation is transferred to a wild-type E. coli K12 strain, the strain becomes temperature sensitive for growth and displays the same characteristics as TAUts7. These findings show that a functional DNA ligase is essential for normal DNA replication and repair in E. coli.