cssi/SciSciGPT-SciSciNet huggingface dataset:
Functional division of the retina and binocular correspondence

Spatial vision relies on a spatial coding of object directions sensed by the retinal photoreceptors. An empirically measured constant error in this coding of perceived space is described classically as a barrel distortion involving long horizontal lines. A Cartesian retinal coordinate system is constructed to describe the transformation from object space to perceived space. This system establishes a subjective horizontal and vertical (isoelevation and isoazimuth) grid for each eye. The retinal entities that mediate subjective sense of constant elevation (horizontal) and constant azimuth (vertical) constitute the functional division of the retina, and they are described by a model with a single parameter zp, which determines the curvatures of a set of hyperbolic isopters. Empirical isoelevation positions were measured, which were described by this model. The best-fitting zp values appeared to be independent of viewing distance, similar for the two eyes of the same observer but differing significantly among observers. The functional-retinal-division model and horizontal retinal shear, as described by Helmholtz, were used to predict the spatial distributions of binocular corresponding points. The disparity field on a frontoparallel plane at a finite viewing distance showed marked asymmetry between the upper and the lower visual fields. The hyperbolic isoelevation and isoazimuth curves dramatically exaggerated this asymmetry. This theoretical disparity field provides a guideline for experiments that attempt to show the effect of binocular disparity in the periphery.
Identification and characterization of nonsubstrate based inhibitors of the essential dengue and West Nile virus proteases

The 72 known members of the flavivirus genus include lethal human pathogens such as Yellow Fever, West Nile, and Dengue viruses. There is at present no known chemotherapy for any flavivirus and no effective vaccines for most. A common genomic organization and molecular mechanisms of replication in hosts are shared by flaviviruses with a viral serine protease playing a pivotal role in processing the viral polyprotein into component polypeptides, an obligatory step in viral replication. Using the structure of the dengue serine protease complexed with a protein inhibitor as a template, we have identified five compounds, which inhibit the enzyme. We also describe parallel inhibitory activity of these compounds against the West Nile virus Protease. A few of the compounds appear to provide a template for design of more potent and specific inhibitors of the dengue and West Nile virus proteases. Sequence similarities among flaviviral proteases suggests that such compounds might also possibly inhibit other flaviviral proteases.
Miniature mass spectrometer equipped with electrospray and desorption electrospray ionization for direct analysis of organics from solids and solutions

Abstract We report on the use of a small light-weight mass spectrometer (MS) for chemical analysis of organic material directly from solution or from the solid state with potential value in future planetary missions. The mass spectrometer used in the experiments reported here is handheld and controlled from a laptop computer through custom software. Detection and identification of small organic molecules, including some that might be prebiotics, was achieved using methods relevant to in situ and remote sensing applications. The miniature MS was equipped with a discontinuous atmospheric pressure interface (DAPI) and a home-built electrosonic spray ionization (ESSI) source. Aqueous solutions of molecules of interest were examined using the ESSI technique, while desorption electrospray ionization (DESI) was applied to examine solid samples. The system performance was characterized by direct analysis of analytes belonging to several compound classes including biotic and abiotic amino acids, purines, pyrimidines, nucleosides and peptides. Detection limits in the sub-ppm range for solutions were achieved with the atmospheric pressure sampling/ionization interface. Tandem mass spectrometry (MS 2 ) was successfully applied to confirm trace detection of target compounds in mixtures. Multiple stage (MS n ) analysis, where n = 3–5, was employed for molecular structure confirmation and to demonstrate the high chemical specificity as well as the sensitivity of the instrumentation. The use of improved versions of this type of mass spectrometer on exploration missions could provide detailed chemical information on organic materials in physical states currently difficult to access. The high sensitivity and specificity, combined with rapid detection and the absence of requirements for sample preparation are encouraging features of the instrumentation.
Computational Design and Elaboration of a De Novo Heterotetrameric α-Helical Protein that Selectively Binds an Emissive Abiological (Porphinato)zinc Chromophore

The first example of a computationally de novo designed protein that binds an emissive abiological chromohore is presented, in which a sophisticated level of cofactor discrimination is pre-engineered. This heterotetrameric, C2-symmetric bundle, AHis:BThr, uniquely binds (5,15-di[(4-carboxymethyleneoxy)phenyl]porphinato)zinc [(DPP)Zn] via histidine coordination and complementary noncovalent interactions. The A2B2 heterotetrameric protein reflects ligand-directed elements of both positive and negative design, including hydrogen bonds to second-shell ligands. Experimental support for the appropriate formulation of [(DPP)Zn:AHis:BThr]2 is provided by UV/visible and circular dichroism spectroscopies, size exclusion chromatography, and analytical ultracentrifugation. Time-resolved transient absorption and fluorescence spectroscopic data reveal classic excited-state singlet and triplet PZn photophysics for the AHis:BThr:(DPP)Zn protein (kfluorescence = 4 × 108 s−1; τtriplet = 5 ms). The A2B2 apoprotein has immea...
A study of intermittent alternating drug program reinduction therapy on the frequency and duration of response in adult acute leukemia

Of 41 adults with a diagnosis of acute leukemia that were randomized for induction therapy in combination with methotrexate, 6-MP, vincristine and prednisone (POMP) versus a combination of cytosine arabinoside, cytoxan, vincristine and prednisone (COAP), 23 (56%) patients achieved a complete remission. During remission, patients received consolidation therapy with the three courses of remission induction regimen that they had not received initially. They then received daunomycin (three courses) and L-asparaginase and were then maintained for two years with their induction therapy. The median duration of survival for all patients was 40 weeks; the median duration of survival of those patients that responded to chemotherapy was 80 weeks. There was no significant difference between the two induction regimens with regard to complete remission more than four and one half years from diagnosis and two and one half years from discontinuation of all therapy.
Low medication adherence and hypertension control among adults with CKD: data from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study.

Background Low adherence to antihypertensive medication is an important barrier to achieving blood pressure control. Few data are available for medication adherence in adults with chronic kidney disease (CKD). Study Design Cross-sectional. Setting & Participants 3,936 and 9,129 participants with and without CKD using antihypertensive medication in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study, respectively. CKD was defined as albuminuria with albumin excretion ≥30 mg/g or estimated glomerular filtration rate 2 . Outcomes Medication adherence and uncontrolled hypertension. Measurements Medication adherence was assessed using a validated 4-item scale. Blood pressure was measured 2 times by trained staff. Results In REGARDS participants with and without CKD, 1,426 (36.2%) and 2,421 (26.5%) had uncontrolled hypertension with blood pressure ≥140/90 mm Hg, and 2,656 (67.5%) and 5,627 (61.6%), ≥130/80 mm Hg. Also, 27.7% of those with CKD and 27.9% of those without CKD responded "yes" to ever forgetting to take their medication and 4.4% and 4.2%, respectively, responded yes to being careless about taking their medication. Also, 5.7% and 5.3% responded yes to missing taking medication when they felt better, and 4.2% and 3.6%, to missing it when they felt sick. Overall, 23.3% and 23.7% of participants with and without CKD responded yes to 1 adherence question, whereas 7.7% and 7.2%, respectively, responded yes to 2 or more adherence questions. In those with CKD, the multivariable adjusted ORs for uncontrolled hypertension (blood pressure ≥140/90 mm Hg) for individuals answering yes to 1 and 2 or more versus 0 adherence questions were 1.26 (95% CI, 1.05-1.51) and 1.49 (95% CI, 1.12-1.98), respectively. Analogous ORs for systolic/diastolic blood pressure ≥130/80 mm Hg were 1.06 (95% CI, 0.78-1.45) and 1.20 (95% CI, 0.88-1.64). Limitations Pharmacy fill data were not available. Conclusions Individuals with CKD had similarly poor medication-taking behaviors as those without CKD.
MAGNETISM OF KCl

At room temperature KCl has a diamagnetic susceptibility of 1.04\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$ cgs units per ${\mathrm{cm}}^{3}$. The value at liquid nitrogen temperatures is \textonehalf{}% smaller. As the temperature is lowered further, a paramagnetic contribution inversely proportional to the temperature becomes apparent in additively or gamma-ray colored material. The magnitude of this paramagnetic contribution, which is proportional to the number of one-electron imperfection centers, is compared to the optical absorption of electron excess centers, to yield a value of 0.6 for the oscillator strength of the $F$ band, and strong evidence that the $M$ center is not paramagnetic. The results also indicate that the $M$ center absorbs under the $F$ band as well as in the $M$ band.
Left ventricular hypertrophy syndrome in infancy.

In infants a group of cardiac lesions exist which produce cardiac enlargement, predominantly of the left ventricle, without the presence of significant murmurs or central cyanosis, and in which there is a tendency to the development of heart failure. Under these circumstances the electrocardiogram may be normal, reveal evidence of myocardial anoxia or of left ventricular hypertrophy. We have called this complex the Left Ventricular Hypertrophy Syndrome. This syndrome does not include more commonly occurring cardiac anomalies which produce left ventricular hypertrophy associated with significant murmurs. It does include (1) primary endocardial fibroelastosis, (2) predominantly myocardial disorders such as (a) idiopathic or aseptic myocarditis, (b) glycogen storage disease of the heart, (c) tumors of the heart and (d) nutritional deficiency states causing myocardial dysfunction; and (3) disorders resulting predominantly in abnormalities of coronary blood flow as (a) anomalous origin of the left coronary artery and (b) coronary occlusive disease. The demonstration of left ventricular hypertrophy in infancy by physical examination, x-ray film and electrocardiography is discussed and the usefulness of vectorcardiography in delineating pathological right ventricular hypertrophy and thereby excluding a diagnosis of left ventricular hypertrophy syndrome is emphasized. The prognosis for survival beyond infancy is grave in these patients and the differentiation from congenital cardiac malformations is important.
Predictors of Behavior Problems in Three‐Year‐Old Sons of Alcoholics: Early Evidence for the Onset of Risk

We investigated risk factors in a population-based sample of alcoholic (father) and comparison families with 3-year-old sons. Alcoholic and comparison parents did not differ in socioeconomic status (SES), education, years married, family size, or cognitive functioning. Antisocial behavior and depression were significantly greater in alcoholic parents. High risk children were more impulsive than comparison children, but there were no differences in developmental age, IQ, or behavior problems. A higher percentage of high-risk children were rated in the extreme clinical range for behavior problems than were comparison children. For alcoholic families, mothers' ratings of their children's total behavior problems, externalizing behavior problems, and internalizing behavior problems were predicted by mothers' lifetime alcohol problems, current depression, and family SES. Father variables failed to predict children's behavior problems. Maternal variables were stronger predictors of their 3-year-old sons' problem behaviors than were paternal variables. Language: en
Role of interatomic bonding in the mechanical anisotropy and interlayer cohesion of CSH crystals

Abstract Atomic scale properties of calcium silicate hydrate (CSH), the main binding phase of hardened Portland cement, are not well understood. Over a century of intense research has identified almost 50 different crystalline CSH minerals which are mainly categorized by their Ca/Si ratio. The electronic structure and interatomic bonding in four major CSH crystalline phases with structures close to those found in hardened cement are investigated via ab initio methods. Our result reveals the critical role of hydrogen bonding and importance of specifying precise locations for water molecules. Quantitative analysis of contributions from different bond types to the overall cohesion shows that while the Si O covalent bonds dominate, the hydrogen bonding and Ca O bonding are also very significant. Calculated results reveal the correlation between bond topology and interlayer cohesion. The overall bond order density (BOD) is found to be a more critical measure than the Ca/Si ratio in classifying different CSH crystals.
SU-FF-T-232: Feasibility Study of a Carbon Nanotube Field Emission Microbeam System for Cellular Irradiation

Purpose: Tissue‐level radiobiological effects that influence tumorcontrol or normal tissue complications stem from processes initiated at the cellular and sub‐cellular levels immediately following radiation energy deposition. The exact mechanisms of these processes at the critical moments are still poorly understood. We proposed to develop a nanotechnology based microbeam pixel array cellular irradiation system that promises to enable researchers to study the micro‐processes at the spatial and temporal scale of the events. This presentation reports the feasibility study results. Method and Materials: A multi‐pixel microbeam cellular irradiation system is proposed to selectively irradiate chosen target cells in a Petri dish under microscope observation. The microbeam system uses carbon nanotube(CNT)field emissiontechnology. Each of the CNT pixels emits an electron beam and a silicon nitride window collimates the electron beam to a specific microbeam size. The electron microbeam has a tunable energy of 20–60 keV. Each of the pixel beams in the multi‐pixel microbeam can be controlled individually. The initial phase of the research is design and development of a prototype single pixel microbeam device and cell irradiation demonstration. Results: We have designed and fabricated a prototype single pixel CNTfield emission microbeam system and performed dose calibration. GAFCHROMIC film is used to measure absolute dose and dose distribution. Microbeam radiation dose is calibrated as dose per radiation pulse. We performed cell irradiation using the prototype microbeam device on Rat‐1 cells. H2AX is phosphorylated at DNA damage sites and the microbeam irradiation pattern is confirmed by the pattern of DNA damage. Conclusion: We have demonstrated the feasibility of a single pixel CNTfield emission microbeam for cellular irradiation. The next research step is study the feasibility of the multi‐pixel microbeam array. This work is funded by NCI (R21 CA118351) and North Carolina Biotechnology Center (2005 MRG‐111).
Radiologic Assessment of Lymph Nodes in Oncologic Patients

Status of lymph node metastasis has important implications in deciding treatment of oncologic patients. The appropriate choice of imaging modality is crucial to obtain accurate evaluation of lymph node status. Current imaging methods are mainly divided into two categories, conventional structural imaging and more recently emerging functional imaging. In depth understanding of these imaging tools is essential in making the correct choice for individual patients, and eventually for better diagnosis and treatment.
Effects of Age on Gene Expression during Estrogen-Induced Synaptic Sprouting in the Female Rat

Age and estrogen treatment influenced fiber outgrowth and compensatory neuronal sprouting after unilateral entorhinal cortex lesions (ECL) which model Alzheimer disease-like deafferentation in the dentate gyrus of the hippocampus. In young F344 rats (3 months old), ovariectomy (OVX) decreased reactive fiber outgrowth by 60%. Sprouting in middle-aged rats (18 months old) was reduced in intact females; no further reduction was caused by OVX. Several astrocyte mRNAs were measured in the dentate gyrus of young and middle-aged female rats in three different estrogen states (sham OVX, OVX, or OVX + estradiol) 1 week after ECL. Glial fibrillary acidic protein (GFAP) mRNA was twofold greater in middle-aged rats than young, although both ages showed threefold increases in response to ECL. In prior studies GFAP was found to be decreased by estradiol treatment 3-4 days after ECL; in this study GFAP mRNA had returned to sham OVX levels in young rats by 7 days post-ECL. Surprisingly, estradiol treatment increased GFAP mRNA levels by 25% above OVX in middle-aged rats. Apolipoprotein E (apoE) mRNA was decreased 20% by age in the dentate, although both age groups showed a 25% increase in apoE mRNA in response to ECL. Apolipoprotein J (apoJ) mRNA was increased 20% in the dentate gyrus of middle-aged rats, and both age groups responded to ECL with a 65% increase in apoJ mRNA. The estrogen state did not alter levels of either apolipoprotein mRNA in the deafferented dentate. The data suggest that the estrogen-induced decrease of GFAP in response to lesions does not persist at 7 days post-ECL during sprouting. Overall effects of age on the dentate gyrus include elevated GFAP mRNA and decreased apoE mRNA. The cortical wound site showed consistent enhancement of GFAP mRNA in both age groups by estradiol above sham OVX and greater responses in middle-aged rats.
Growth-dependent AIB and meAIB uptake in LLC-PK1 cells: Effects of differentiation inducers and of TPA

Cultured pig kidney cells designated LLC-PK1, previously shown to acquire Na+-dependent concentrative transport of hexoses as the cells become growth arrested, also show Na+-dependent concentrative uptake of the amino acid analogs alpha-aminoisobutyric acid (AIB) and (methyl) meAIB. This A system-like transport is most active in sparse, growing cultures and becomes stepped down at confluence. The cell/medium equilibrium distribution ratio of the lipophilic cation tetraphenylphosphonium ion (TPP+) decreases in parallel fashion, suggesting that a decrease in membrane potential may be a major factor in the stepdown. Differentiation inducers (hexamethylene bisacetamide) and phosphodiesterase inhibitors (theophylline, methylisobutyl xanthine) accelerate the stepdown, but even in the presence of these compounds addition of the tumor promoter 12-0-tetradecanoylphorbol-13-acetate (TPA) results in the maintenance of a high level of AIB and meAIB uptake. In all these respects the changes in A system-like amino acid transport are the reciprocal of those seen for concentrative hexose transport, although the driving force appears to be the same for both systems. The TPA analogs phorbol and 4-0-methyl TPA which are inactive in tumor promotion are inactive in this system as well. In confluent, already stepped-down cultures, addition of TPA leads to a rapid (2-6 hour) stimulation of AIB and meAIB uptake. The enhancement is sensitive to cycloheximide and actinomycin D. The ouabain-sensitive fraction of meAIB uptake is not markedly changed in the TPA-enhanced uptake, nor is the TPP+ distribution ratio elevated in TPA-treated cells, making it unlikely that the TPA effect is through an alteration in the membrane potential.
Reconstitution of isolated Rieske Fe-S protein into a Rieske-depleted cytochrome b6-f complex.

Abstract The Rieske Fe-S protein can be isolated from the cytochrome b6-ƒ complex by means of chromatography on a hydroxyapatite column in the presence of detergent. Depletion of the cytochrome complex from the Rieske protein results in the loss of oxidoreductase activity, as well as the ability to reduce cytochrome b6. The Rieske Fe-S protein can be reconstituted into the Rieske-depleted complex by removal of the Triton X-100 molecules associated with the protein fractions, and their substitution by lipids. Upon reconstitution the complex is reactivated, and the role of the Rieske Fe-S protein in the reduction of both plastocyanin and cytochrome b6 can be demonstrated.
The role of Polycomb-group response elements in regulation of engrailed transcription in Drosophila

Polycomb group proteins are required for long-term repression of many genes in Drosophila and all metazoans. In Drosophila , DNA fragments called Polycomb-group response elements (PREs) have been identified that mediate the action of Polycomb-group proteins. Previous studies have shown that a 2 kb fragment located from -2.4 kb to -395 bp upstream of the Drosophila engrailed promoter contains a multipartite PRE that can mediate mini- white silencing and act as a PRE in an Ubx -reporter construct. Here, we study the role of this 2 kb fragment in the regulation of the engrailed gene itself. Our results show that within this 2 kb fragment, there are two subfragments that can act as PREs in embryos. In addition to their role in gene silencing, these two adjacent PRE fragments can facilitate the activation of the engrailed promoter by distant enhancers. The repressive action of the engrailed PRE can also act over a distance. A 181 bp subfragment can act as a PRE and also mediate positive effects in an enhancer-detector construct. Finally, a deletion of 530 bp of the 2 kb PRE fragment within the endogenous engrailed gene causes a loss-of-function phenotype, showing the importance of the positive regulatory effects of this PRE-containing fragment. Our data are consistent with the model that engrailed PREs bring chromatin together, allowing both positive and negative regulatory interactions between distantly located DNA fragments.
Processability of Rubber and Rheological Behavior

Abstract The rheological and ultimate properties of unvulcanized rubber and compounds are described. Unfilled elastomers may be represented by the theory of viscoelastic fluids. Various experimental studies are described and interpreted. Filled polymer melts exhibit more complex behavior including yield values, reduced elastic memory, and thixotropy. The influence of these properties on several processing operations including milling/mixing and extrusion is critically discussed.
Segregants from lysogenic heterogenotes carrying recombinant lambda prophages.

Abstract The segregation from lysogenic heterogenotes in which λ and λ dg are distinguished by several genetic markers has been examined. Recombination between the two prophages is correlated with loss of λ dg. The results suggest that the prophage genetic map is a circular permutation of the map for the vegetative phage.
Attributes of Several Methods for Detecting Discontinuities in Mean Temperature Series

Abstract Simulated annual temperature series are used to compare seven homogenization procedures. The two that employ likelihood ratio tests routinely outperform other methods in their ability to identify modest (0.33°C; 0.6 standard deviation anomaly) shifts in the mean. The percentage of imposed shifts that are detected by these methods is similar to that based on tests that rely on a priori metadata information concerning the position of potential shifts. These methods, along with a two-phase regression approach, are also best at identifying and placing multiple shifts within a single time series. Although the regression procedure is better able to detect multiple breaks that are separated by relatively short time intervals, in its published form it suffers from a higher-than-expected Type I error rate. This was also found to be a problem with a metadata-based procedure currently in operational use. The likelihood tests are strongly influenced by the presence of trends in the difference series and shor...
Susceptibility of PharmChek drugs of abuse patch to environmental contamination

The key component of the PharmChek sweat patch, the membrane, has been tested for the passage of externally applied materials. Drugs in the uncharged state rapidly penetrated the membrane but charged species were greatly slowed. In basic media, detectable concentrations of cocaine, methamphetamine, and heroin were observed at the earliest collection time (ca. 30 s), after drugs were placed on the outside of the membrane. Drug concentrations increased over the 2 h time course, when amounts detected (1710 ng cocaine, 1060 ng methamphetamine, 550 ng heroin per pad at 2 h) represented 5-17% of the drug deposited on the surface of the sweat patch. Drugs externally applied to human skin were shown to bind readily. Drugs deposited on the skin of drug-free volunteers several days prior to application of the sweat patch were not completely removed by normal hygiene or the cleaning procedures recommended before application of the sweat patch. Even 6 days of normal hygiene did not remove all drugs from externally contaminated skin and positive sweat patches resulted. A mechanism for passage of drugs through the sweat patch membrane, a mechanism for retention of drugs on skin, and a redesign of the sweat patch and modification of its use to reduce external contamination are proposed. Appropriate care should be taken in the interpretation of positive results from a sweat patch test until more research is conducted.
Optimal Design and Control Scheme for Continuous Capacitive Compensation of Distribution Feeders

Distribution automation schemes being considered for implementation by electric utilities will rely heavily on substation-based computers for control of reactive power on primary feeders. To assist such implementation a new, continuously controllable, capacitive compensation scheme for primary distribution feeders is presented. This compensation scheme allows optimal placement and sizing of time- variable capacitors based on an optimal operating strategy which provides for power loss minimization as a function of time. A numerical example involving a realistic physically-existing feeder is provided to exemplify the design and control schemes.
Initial Sintering of ZnO

ZnO compacts were sintered in air from 450° to 700° C. By mercury porosimetry, pore size distributions, surface areas, densities, and porosities were determined. No shrinkage occurred below 550°C and, from a surface loss model, the mechanism was concluded to be surface diffusion. Activation energies are compared with those reported by other authors.
The Impact of Strategic‐Positioning Information on Auditor Judgments about Business‐Process Performance

Strategic‐systems auditing (SSA) approaches require auditors to perform analyses of their clients at two levels (i.e., strategic and business‐process levels) when conducting audits (e.g., Bell et al. 2002; Lemon et al. 2000). One advantage of using SSA approaches is that through these analyses, auditors gain a complex systems understanding of the client. This understanding enhances decision making in part by recognizing that small actions can have big effects that increase overall business risk (Jacobson 2001; Richmond 2000). This study examines how the two levels of analysis in SSA impact auditor judgments regarding small changes in a business process that can have big (risk‐increasing) effects. Specifically, we predict that when strategic‐positioning information (contained within the strategic‐level analysis) indicates a client is typical of others in its industry, information at the business‐process level regarding a small problem in a business process will be weighted less than when the strategic‐posi...
Efficient generation of red and blue light from 1.32 /spl mu/m in partly-periodically-poled KTiOPO/sub 4/ crystal

Summary form only given. Recently, we reported obtaining THG by cascading non-phase-matched SHG and sum frequency generation in a single cerium-doped KTiOPO/sub 4/ (Ce:KTP) crystal from femtosecond laser pulses at 1.32 /spl mu/m. A conversion efficiency of 0.17% was achieved at a pump intensity of 3.2/spl times/10/sup 11/ W/cm/sup 2/. In order to improve the conversion efficiency, we have designed a new KTP structure by using quasi phase-matched (QPM) SHG to replace the previous non-phase-matched SHG. Here, we report our first result of efficiently generating coherent blue light in this crystal.
Stochastic Strategies for Autonomous Robotic Surveillance

In this paper, we consider a team of autonomous mobile robotic agents engaged in a surveillance mission. It is desirable not to have the agents move in a predictable fashion so no intruder or invader can plan their movements to avoid the surveillance agents. This paper investigates the use of stochastic rules to guide the motions of the agents throughout their surveillance missions. The research emphasizes methods which minimize centralized computation and communication requirements by focusing on local rules for each agent. We define a formal mathematical approach to analyzing the surveillance problem. We take a general environment and impose some mathematical structure on it. We then define a measure of non-uniformity by which we can compare the surveillance coverage of different systems as well as employ a technique to measure the parametric randomness of each strategy. Drawing on the existing literature on stochastic techniques for searching a graph by a single agent, we study the problem of finding optimal rules for searching a graph using a team of agents. In certain cases, search strategies may be evaluated in terms of explicit closed-form expressions for steady-state distributions. In general, however, strategies must be evaluated by Monte-Carlo methods. We present a decomposition technique by means of which any of the graphs types under discussion may be uniquely decomposed into a collection of complete subgraphs. We developed a surveillance strategy for handling general graphs through a hybrid solution to our less complex decompositions.
Spontaneous Ca2+ transients in developing hippocampal pyramidal cells.

To determine the spatiotemporal pattern of hippocampal pyramidal cell activity during development, we examined cytosolic Ca2+ dynamics in tissue slices derived from early postnatal rats. After a brief (12–60 h) culture period, slices were stained with a calcium-sensitive dye, Fluo-3. Fluorescence imaging of the Fluo-3-stained slices with a scanning laser confocal microscope afforded simultaneous observation of many cells at high spatial resolution. Time-lapse imaging revealed spontaneous Ca2+ transients in the somata and dendrites of many pyramidal cells in areas CA1 and CA3. For the most part, Ca2+ activity in neighboring pyramidal cells appeared to be uncorrelated, although we occasionally observed synchronous Ca2+ transients in adjacent cells. The transients were blocked by both tetrodotoxin (1 μM) and a mixture of the glutamate receptor antagonists, APV (50 μM) + CNQX (10 μM). Thus, spontaneous Ca2+ transients appear to be a consequence of activity-dependent release of glutamate acting postsynaptically through ionotropic glutamate receptors. Although γ-aminobutyric acid (GABA) is thought to be an excitatory neurotransmitter during hippocampal development (Cherubini et al., 1991, Trends Neurosci.14(12):515–519), the spontaneous Ca2+ transients were not blocked by the GABAA receptor antagonist picrotoxin (100 μM). Furthermore, application of GABA (50 μM) abolished the spontaneous Ca2+ events, possibly via GABAB receptor-mediated inhibition of postsynaptic cells. The present results join other recent observations suggesting that isolated neural tissues support spontaneous activity, although the patterns and mechanisms of the activity reported here appear to differ from those of previous studies. Differences in the patterns of spontaneous activity during development may contribute to variations in the functional organization of different regions of CNS tissue. 1994 John Wiley & Sons, Inc.
Effects of tirofiban on haemostatic activation in vitro

Background. Thrombin plays a critical role in normal haemostasis and pathological thrombosis. Heparin has long been a mainstay choice of antithrombotic regimen in cardiac patients, but persistent thrombin generation seems to occur during heparin therapy. Because platelets are integral to primary haemostasis and clot formation, we evaluated the use of tirofiban (Aggrastat®),a platelet inhibitor, as a therapy to improve heparin sensitivity and delay thrombin formation. Methods. Blood samples were obtained from healthy subjects (n=8) and cardiac surgical patients (n=34). Thrombin formation was measured in platelet-rich plasma with a Thrombogram®-Ascent fluorescent plate reader system. Platelet inhibition by tirofiban was evaluated with Plateletworks®, and the interaction of tirofiban and heparin (>1.5 U ml−1) on clot formation was evaluated with Sonoclot Analyzer® or kaolin activated clotting times (ACTs). Results. Addition of tirofiban (70–280 ng ml−1) progressively delayed onset of thrombin generation triggered by adenosine diphosphate (ADP). Plateletworks showed platelet inhibition with tirofiban (>35 ng ml−1), whereas heparin per se failed to produce platelet inhibition at 7 U ml−1. Heparin (1.5 U ml−1) slowed the onset and rate of fibrin formation on Sonoclot analyses, and this was further slowed after addition of tirofiban (70 ng ml−1) to heparin-containing blood samples. Significant increases in ACT at all heparin concentrations were observed with the addition of tirofiban (70 ng ml−1). The addition of antithrombin (0.2 units/ml) to heparinized blood samples further prolonged ACTs, but the difference was not statistically significant when compared with heparin alone. Conclusion. Tirofiban delays platelet activation-mediated thrombin generation and prolongs ACT in heparinized blood.
Current Trends and Issues in Family Nursing Research

The purposes of this article are: (a) to examine current trends and issues in family nursing research from the perspective of an intimate outsider to the field, and (b) to offer predictions regarding future trends for family nursing research. The article is divided into three sections. First, the unique dimensions offamilies are identified and the problems these characteristics present to researchers are briefly examined. Second, a brief overview of the topics studied in family nursing research and the methodological issues of that body of literature are presented. Finally, conclusions are drawn and observations are made about the current status of family nursing research, and recommendationsfor thefuture are offered. Among the predictions are an increase in multidisciplinary research teams, greater use of midrange theories, an increase in conceptual and methodological complexity, more study offamily diversity, greater use offeministframeworks, and an increase in the number offamily nursing scholars who h...
B Cells Promote Induction of Experimental Autoimmune Encephalomyelitis by Facilitating Reactivation of T Cells in the Central Nervous System

The efficacy of rituximab treatment in multiple sclerosis has renewed interest in the role of B cells in CNS autoimmunity. In this study, we show that B cells are the predominant MHC class II + subset in the naive CNS in mice, and they constitutively express proinflammatory cytokines. Incidence of experimental autoimmune encephalomyelitis induced by adoptive transfer was significantly reduced in C3HeB/Fej μMT (B cell–deficient) mice, suggesting an important role for CNS B cells in initiating inflammatory responses. Initial T cell infiltration of the CNS occurred normally in μMT mice; however, lack of production of T cell cytokines and other immune mediators indicated impaired T cell reactivation. Subsequent recruitment of immune cells from the periphery driven by this initial T cell reactivation did not occur in μMT mice. B cells required exogenous IL-1β to reactivate Th17 but not Th1 cells in vitro. Similarly, reactivation of Th1 cells infiltrating the CNS was selectively impaired compared with Th17 cells in μMT mice, causing an increased Th17/Th1 ratio in the CNS at experimental autoimmune encephalomyelitis onset and enhanced brain inflammation. These studies reveal an important role for B cells within the CNS in reactivating T cells and influencing the clinical manifestation of disease.
Effects of Quadriceps Femoris Muscle Strengthening on Crouch Gait in Children With Spastic Diplegia

Background and Purpose. Despite evidence of weakness in children with cerebral palsy, the use of strength training in this population remains controversial. Subjects. Fourteen children with spastic diplegia, ranging in age from 6 to 14 years (X=9.1, SD=2.5), participated in a bilateral quadriceps femoris muscle strengthening program. Methods. The children exercised three times per week for 6 weeks using ankle weights at loads of approximately 65% of each child's maximum isotonic force production. The maximal voluntary contraction of the quadriceps femoris muscles was measured before, at the midpoint of, and immediately following the exercise program at 30, 60, and 90 degrees of knee flexion. Gait analyses were performed before and after the strengthening program to determine whether quadriceps femoris muscle strengthening influenced gait. Results. Children with spastic diplegia can increase quadriceps femoris muscle strength through heavy resistance exercise. Repeated-measures analysis of variance and multivariate analysis of variance procedures were used to assess changes in force and in gait variables. Improvement in the degree of crouch at initial floor contact at the freely selected speed and an increase in stride length at free and fast speeds were found. Conclusion and Discussion. These findings suggest that resistance exercise is an effective treatment strategy and as such should be considered as one component in the habilitation of children with cerebral palsy.
The Most Addictive Drug, the Most Deadly Substance: Smoking Cessation Tactics for the Busy Clinician

By several measures, nicotine is the world’s most highly addictive drug, and tobacco is its most deadly substance. Worldwide, 1 billion people smoke cigarettes. In the United States alone there are more than 46 million nicotine addicts. Their use of smoked tobacco results in nearly 400,000 deaths per year caused by direct use; there are another 50,000 deaths in nonsmokers because of exposure to secondhand smoke. The total number comprises one out of every five deaths in the United States [1–3]. More than 20% of American adults are current smokers [4], and 23% of US high school students have smoked cigarettes in the last month [5]. Approximately half of all smokers die prematurely from a smoking-related illness [6,7]. Smoking in the United States accounts for one third of all cancer deaths, one fourth of all cardiovascular deaths, and most deaths from chronic respiratory disease. Smoking produces enormous morbidity and incalculable suffering, with more than 8 million Americans suffering from chronic disease and debilitation because of tobacco use [6,7]. For these reasons and a healthy dose of social ostracism, most smokers would like to quit, and more than half of them have abstained from smoking for at least 24 hours in the last year. Almost all of them will fail, however, with successful annual cessation rates less than 5%. With repeated efforts, which average eight quit attempts before success, most individuals do eventually quit, often in the face of grave illness. More than 50 million Americans are ex-smokers. A fundamental clinical goal is to achieve cessation before the onset of serious disease. A person who continues to smoke loses
"Where There Is a Will, There Is an A": Examining the Roles of Self-Efficacy and Self-Concept in College Students' Current Educational Attainment and Career Planning.

As previous research indicates self-efficacy and self-concept have similar effects on achievement outcomes, the current study investigated the differential effects of both constructs on academic performance and career path certainty in college freshmen. Results indicated high school GPA was best predicted by general self-efficacy, whereas current GPA was most strongly related to self-efficacy for learning. However, academic competence did not moderate either self-efficacy or academic performance. Career path certainty was best explained by general self-efficacy and job competence, and scholastic competence best predicted current academic performance. Yet, no mediation effect was found for general self-efficacy amongst the variables of self-concept, academic performance, and career path certainty.
Accuracy Considerations of Time-Splitting Methods for Models Using Two-Time-Level Schemes

In their recent paper, Wicker and Skamarock (2002, hereafter WS) describe a novel adaptation of a timesplitting method (Klemp and Wilhelmson 1978) for integrating the elastic equations but applied to a basic explicit time integration scheme of Runge–Kutta type. The basis for their time integration method is an explicit three-stage, one-step (two time level) scheme that they refer to as a “third-order Runge–Kutta” scheme. The conventional second-order Runge–Kutta and Adams–Bashforth schemes are both formally unstable when applied to pure oscillatory linear modes without artificial damping (Gear 1971). The explicit but economical “leapfrog” or “midpoint” method is unstable for damped modes and, in practice, requires the intervention of a time filter (Asselin 1972) to control the otherwise undamped computational “parasitic” mode in wave simulations. The method of WS, in contrast, has excellent properties of stability for both oscillatory and damped modes and, with the splitting method they propose, permits the efficient integration of a fully elastic and nonhydrostatic atmospheric model. However, as we show below, a careful analysis of the basic method they propose upon which they build their splitting scheme reveals that it is not strictly accurate to third order (except for the very special case of purely linear dynamics, where its response does exactly match that of any true three-stage third-order Runge–Kutta method) but is better thought of as a three-stage second-order method with superior characteristics of stability and accuracy. While alternative fully third-order schemes of Runge–Kutta type are discussed, the difficulties of combining these with robust splitting methods may preclude their practical implementation in numerical weather prediction models.
Contrast-enhanced sonography in pediatrics

Microbubble US contrast agents are composed of an outer shell of protein, phospholipid or polymer that encase air or perfluorocarbon gas. These contrast agents have been widely used in adult cardiology patients to improve endocardial border delineation and have been proved safe and well tolerated in this patient population. There is also a growing body of literature elucidating the value of contrast-enhanced sonography to distinguish benign from malignant liver lesions in adults and to characterize non-hepatic adult malignancies. Because these agents have not been approved for pediatric use in many countries, less is known of the value of contrast-enhanced sonography in children. In this review I will discuss several proven and potential pediatric applications of contrast-enhanced sonography.
Subjectivity and the Elusiveness of the Self

‘Where am I?’ This is something we might expect to hear from hapless explorers or academics with no sense of direction. If we can, we’ll explain to our inquirer that he is east of East St. Louis and hope he can fi nd his way from there. If he persists, insisting that he is not really lost, but only cannot fi nd himself no matter how hard he looks, we might reasonably suspect that we are dealing with that peculiarly incorrigible academic explorer, the philosopher. When we hesitantly point to his body, we hear him explain, exasperated, ‘No, don’t you get it? That’s my body, but I’m looking for my self! And I cannot fi nd it!’ At this point it is tempting to slip away, convinced that our philosophical friend is throttling himself with the noose of his own cleverness and is at risk of intellectual suicide by denying that he in fact has a self. Nevertheless, we shouldn’t turn away so quickly: some pretty ingenious people from radically diverse schools of thought have endorsed the claim that the self ineluctably evades detection. Hume gets credit for this ‘insight’ in analytic circles, but in the continental tradition we can fi nd Sartre making a similar claim, and even further from the Anglo-American philosophical tradition we fithe Buddhists suggesting that the liberation from the very idea of a self is necessary for enlightenment.
On the expected file download time of the random time-based switching algorithm in P2P networks

The expected file download time of the random time-based switching algorithm for peer selection and file downloading in a peer-to-peer (P2P) network is still unknown. The main contribution of this paper is to analyze the expected file download time of the time-based switching algorithm for file sharing in P2P networks when the service capacity of a source peer is totally correlated over time, namely, the service capacities of a source peer in different time slots are a fixed value. A recurrence relation is developed to characterize the expected file download time of the time-based switching algorithm. It is proved that for two or more heterogeneous source peers and sufficiently large file size, the expected file download time of the time-based switching algorithm is less than and can be arbitrarily less than the expected download time of the chunk-based switching algorithm and the expected download time of the permanent connection algorithm. It is shown that the expected file download time of the time-based switching algorithm is in the range of the file size divided by the harmonic mean of service capacities and the file size divided by the arithmetic mean of service capacities. Numerical examples and data are presented to demonstrate our analytical results.
HgBr (B-X) formation due to collisions involving O+/ and HgBr2 at kinetic energies (lab.) above 100 eV

Observation du systeme de bandes (B-x) de HgBr et des raies atomiques de Hg emis lors des collisions O + /O 2 + avec HgBr 2 dans la gamme d'energie 100-1000 eV
Localization of dichlorofluorescin in cardiac myocytes: implications for assessment of oxidative stress.

Localization and staining features of the oxidant-sensitive fluorescent probe 2′7′-dichlorofluorescin (DCFH) were evaluated in isolated cardiac muscle cells. Cardiomyocytes rapidly accumulated the ...