cssi/SciSciGPT-SciSciNet huggingface dataset:
678 Predictors of Sleep Health among Older Adults During the Initial Months of the Covid-19 Pandemic

Introduction: Since the first COVID-19 case was reported in January 2020 in the United States, there have been more than 18.8 million cases and 330,000 deaths. In order to minimize the risk of potential COVID- 19 transmission, many states instituted stay at home orders and closed churches, gyms, and other places that older adults often participate in social gatherings. Little is known about sleep health among older adults during this time. The purpose of this study was to examine the relationship between older adult's personal factors, health behaviors, and sleep health during the initial months of the Covid-19 pandemic. Methods: Adults age 60 and older participated in an online anonymous survey recruited through email lists of community senior organizations and university alumni using a snowball approach. Personal factors included age (years), gender (female=0, male=1), living situation (living alone=0, living with others=1), education (≤12 years = 0, >12 years = 1), and income (75000=1), and depressive symptoms (CESD-10). Health Behaviors included moderate physical activity (0=none, 1=yes), smoking (0=no, 1=yes), drinking (number of drinks). Sleep Health was assessed using the multidimensional SATED scale (Satisfaction, Alertness, Timing, Efficiency, and Duration). Backward stepwise regression analysis was used to test if personal factors and health behaviors significantly predicted participants' sleep health. Results: Participants included 509 adults (392 Females;mean age=75.6 years;SD=5.0;range 63-93 years). The majority were white (n=466;92%) and 93% (n=471) had a college education. Seventy-four percent (n=71) participated in moderate exercise, 94% (n=478) did not smoke, and 58% (n=286) did not report drinking alcohol. Sleep Health was variable with 179 (36%) reporting poor sleep health (mean=7.4;SD=2.1). Regression results indicated that gender, years of education, living situation, income, depressive symptoms and moderate exercise explained 17% of the variance in sleep health (R2=0.169, F,6=14.4, p=0.000). Conclusion: These findings suggest that many older adults experienced poor sleep health associated with depressive symptoms and exercise participation during the initial months of the pandemic. Future studies should examine the long-term effects of the pandemic on the sleep health of older adults.
Sexual violence and cardiovascular disease risk: A systematic review and meta-analysis.

Abstract Background Cardiovascular disease (CVD) is a leading cause of death among adults. Over 35% of women worldwide report lifetime exposure to sexual violence. While psychosocial factors broadly have been linked to CVD risk, it is unclear if a history of sexual violence is associated with increased risk for CVD. This study employed quantitative meta-analysis to investigate the association between sexual violence and CVD risk. Methods PubMed and PsycINFO databases were searched through March 1, 2021. Included articles had a measure of sexual violence and at least one cardiovascular outcome (i.e., clinical CVD, subclinical CVD, select CVD risk factors) in women and men aged 18 years or older. Data were expressed as odds ratios (OR) or hazard ratios (HR) with 95% confidence intervals (CI) extracted from fully-adjusted models. OR and HR effects were pooled separately, given the inability to statistically harmonize these effects and differences in interpretation, using random effects meta-analysis. Heterogeneity of effects was tested using Cochran's Q test. Results Overall, 45 articles based on 830,579 adults (77.1% women) were included (113 individual effects expressed as OR and 9 individual effects expressed as HR). Results indicated that sexual violence was related to adult CVD risk (OR [95%CI] = 1.25 [1.11-1.40]; HR [95%CI] = 1.17 [1.05-1.31]). Results varied by outcome type and measurement, and timing of violence. Conclusions Adults with a history of sexual violence demonstrate greater CVD risk relative to those without this history. The results highlight the importance of addressing sexual violence in CVD risk reduction efforts.
Glassy Dynamics and Relaxation in Proteins

Proteins have a free energy landscape possessing a large number of energy valleys separated by energy mountains.1,2,3 Many, perhaps all, complex systems have a rugged free energy landscape, including glasses4, spin glasses5, evolution6,7, and neural nets.5,8 The energy valleys, or minima, are called conformational substates (CS) and correspond to different structures in a protein or structural glass. Recent work shows analogies between proteins and glasses: The connection is between a single protein molecule (not a protein ensemble) and a glass sample. At low temperatures a protein or a glass is caught in a single free energy valley or conformational substate. As temperature increases, a glass liquifies and a protein moves from CS to CS. If temperature is then lowered below a transition temperature, a protein or a glass is again caught in a single CS. Proteins like glasses experience metastability below a transition temperature. In addition, both proteins and glasses display slow relaxation processes with non-exponential time dependence and non-Arrhenius temperature dependence.
Linear polarization measurements of Comet C/2011 W3 (Lovejoy) from STEREO

Abstract The spectacular Kreutz sungrazing comet C/2011 W3 (Lovejoy) was well observed by the coronagraphs aboard the Solar and Heliospheric Observatory (SOHO) and the twin Solar and Terrestrial Relations Observatory (STEREO) spacecraft during both the inbound and outbound passages about perihelion on 16 December 2011. The combination of the two STEREO viewpoints covers a large range of phase angles for which the polarization dependence can be measured. Extremely large polarization levels were measured for Comet Lovejoy, ranging from −15 ± 3% in the negative branch at low phase angles, to as much as 58% or more in the positive branch. To the best of our knowledge, these high polarization levels are completely unprecedented. The negative branch extends to larger phase angles than usual, with the highest negative polarization occurring around 35°, and the transition from negative to positive polarization occurring around 45–50°. Stratification along the tail was also detected, with the degree of polarization increasing with greater distance from the nucleus. Although cometary dust grains are typically modeled as aggregates, we speculate based on results available in the literature that these observations can be best explained by nearly spherical or somewhat aspherical magnesium-rich silicate particles stratified by size, with size distributions characterized by effective size parameters ranging from x eff = 2 – 3 near the nucleus to x eff 1 farther back in the tail. However, additional modeling would be needed to better understand the implications of these unusual polarization measurements.
Design and fabrication of curved micromirrors using the MultiPoly process

This paper presents the design and fabrication of reflective curved micromirrors with pre-determined static shapes. The fabrication of these devices uses conventional surface micromachining technology and the MultiPoly process (Yang et al., 2000), which is a technique for depositing multilayers of LPCVD polysilicon in order to control the overall stress and stress gradient. The inexpensive fabrication of these micromirrors allows for a range of designs that could address many applications, including optical switches.
Keep Your Head to the Sky: Interpreting African American Home Ground

Keep Your Head to the Sky: Interpreting African American Home Ground. Grey Gundaker. ed., with the assistance of Tynes Cowan. Charlottesville: University Press of Virginia, 1998. 344 pp.
Ethnic differences in use of inpatient mental health services by blacks, whites, and Hispanics in a national insured population.

OBJECTIVE. We examine whether ethnic differences in use of inpatient mental health services exist when the usually confounding effects of minority status and culture are minimized or controlled. DATA SOURCES AND STUDY SETTING. Secondary analyses were conducted using a national insurance claims database for 1.2 million federal employees and their dependents insured by the Blue Cross/Blue Shield (BC/BS) Federal Employees Plan (FEP). STUDY DESIGN. The Andersen-Newman model of health utilization was used to analyze predisposing, enabling, and need variables as predictors of inpatient mental health utilization during 1983. The study design was cross-sectional. DATA COLLECTION. The study database was made up of BC/BS insurance claims, Office of Personnel Management employee data, and Area Resource File data. PRINCIPAL FINDINGS. No significant differences were found among blacks, whites, and Hispanics in the probability of a psychiatric hospitalization or in the number of inpatient psychiatric days. Regression analyses revealed younger age and psychiatric treatment of other family members as significant predictors of a hospitalization; region of residence, younger age, hospital bed availability, and high option plan enrollment were significant predictors of the number of treatment days. CONCLUSIONS. Ethnic differences in use of inpatient mental health services were not significant in this generously insured population. Further research involving primary data collection among large and diverse samples of ethnic individuals is needed to fully examine the effects of cultural and socioeconomic differences on use of mental health services
The Invasive Ailanthus altissima in Pennsylvania: A Case Study Elucidating Species Introduction, Migration, Invasion, and Growth Patterns in the Northeastern US

Abstract Ailanthus altissima (Tree of Heaven), an invasive tree species native to China and East Asia, was first introduced into the US ca. 1784 by William Hamilton at his Philadelphia, PA estate. However, the means and temporal progression of spread from this and other early points of introduction are not clear. This species now occurs in >40 US states, primarily as an urban and roadside weed. The Northeast supports the highest densities of Ailanthus within the US, mainly in transportation corridors and urban areas, where it has become the dominant tree species. A recent, widespread increase in Ailanthus incidence in eastern hardwood forests, not unlike prior invasions along railways and roadsides, suggests that current conditions favor invasion in natural environments. To help elucidate the life history of Ailanthus in Pennsylvania and the northeastern US, as well as answer fundamental biological questions concerning this species, we conducted dendrochronological (tree-ring) studies and floristic survey...
Distinct subpopulations of epithelial ovarian cancer cells can differentially induce macrophages and T regulatory cells toward a pro-tumor phenotype.

Problem The presence of immune infiltrates in the tumor does not always correlate with an anti-tumoral immune response. We previously identified two sub-populations of epithelial ovarian cancer (EOC) cells with differential cytokine profile. We hypothesize that these two sub-populations of EOC cells may differentially regulate the immune phenotype in the tumor microenvironment and therefore affect the immune response.
The taste system encodes stimulus toxicity

Abstract Attempts to define the organization of the taste system in terms of the physical characteristics of stimuli have been largely unsuccessuful. We recorded taste-evoked neural activity in the rat's hindbrain and determined that stimuli could be effectively organized along a physiological dimension which corresponds to stimulus toxicity. Taste is a visceral sense that mediates between the external and internal chemical environments. Its responsiveness to a wide range of chemicals and its organization along a dimension which promotes the organism's physiological welfare ideally suit it to that purpose.
Cooperative estimation in heterogeneous populations

We consider the problem of cooperative distributed estimation within a network of heterogeneous agents. We begin with the situation where each agent observes an independent stream of Bernoulli random variables, and the goal is for each to determine its own Bernoulli parameter. However, the agents of the population can be categorized into a small number of subgroups, where within each group the agents all have identical Bernoulli parameters. We present an algorithm for cooperative estimation in this setting which allows each agent's estimate to asymptotically converge to the correct value. We show how our technique can be applied in other settings, such as in heterogeneous least mean squares filter populations. Finally, we present simulation results showing the benefit of our technique, and compare it to noncooperative parameter estimation in a Bernoulli population.
Taking the MDGs Beyond 2015: Hasten Slowly

The authors advise to hasten slowly in defining the successor framework to the MDGs. The review of progress in 2010 should not be intermingled with the intergovernmental discussions about the post‐2015 framework. The latter should not start until a UN panel of Eminent Persons has prepared a set of thoughtful options and suggestions. The worst decision would be to keep the same MDGs and add new Goals and more Targets. The panel will have to address the following topics: (a) new structure; (b) new Targets; (c) collective nature of global Targets; (d) type of benchmarks; (e) new time horizon; and (f) disaggregated monitoring. The world will miss the MDGs largely because disparities within the majority of countries have grown to the point of slowing down national progress. In order to overcome the ‘tyranny of averages’, this article proposes a method of incorporating equity in national statistics.
Forecasting the Coastal Ocean: Resolution, Tide, and Operational Data in the South Atlantic Bight

Abstract This paper addresses shelf-scale simulation with dominant open-water boundary conditions obtained by inversion of interior data. Important, established operational data streams are located along the shore of the study area, in areas influenced strongly by the local geometry. Failure to properly resolve the modeled near field surrounding these data results in their incorrect interpretation, causing invalid inversions and erroneous field estimates far across the shelf. Specifically, improving the model fit to the unresolved data leads to skill degeneration farther offshore and generally unacceptable field estimates remarkably far from shore. Proper near-field resolution leads to valid interpretation and inversion of the same data, with high inverse skill apparent across the shelf. The resolution required is within reach of today's technology.
Development and validation of a gradient reversed-phase high-performance liquid chromatographic assay for S(-)-2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0923) from a transdermal delivery system.

A gradient reversed-phase HPLC method for potency determination of N-0923 (10 mg) from a transdermal delivery system (TDS), was developed and validated with single point calibration using internal standard quantitation. N-0923 and the internal standard, N-0434, are eluted from a reversed-phase C18 column using a gradient which contains 0.1 M triethylamine-0.04 M citrate buffer, pH 5.9, water, and acetonitrile with UV detection at 272 nm. N-0923 is isolated from the transdermal delivery system by extraction with n-heptane followed by extraction of the resulting organic phase with 0.1 M citric acid containing the internal standard. The method was free from matrix interferences in both untreated and forced degraded placebo delivery systems. Acceptable linearity and quantitative recovery from spiked placebo delivery systems over the range 50-150% of nominal label claim were demonstrated. Within-day assay precision from individual samples of active transdermal delivery systems (n = 10) was 5.6% R.S.D. The detection limit was at least 0.1 microgram/ml which is equivalent to 0.05% of the working standard concentration. Replicate injection precision at this level was 0.08% R.S.D. (n = 4). Analysis of thermally stressed active and placebo delivery systems with this HPLC method and photodiode-array detection showed that the chromatography was stability-indicating as demonstrated by the absence of measurable interferences from principal degradation products of either the n-0923 or the delivery system excipients.
Testing dimensionality in the multivariate analysis of variance

Abstract In the multivariate one-way classification with fixed or random effects the between-group effects may be restricted to a lower dimensional space. The problem of testing the dimension of the effect space is treated. For the balanced random effect model the asymptotic null distribution of the likelihood ratio statistic is discussed; the asymptotic distribution is not chi-squared. For the unbalanced fixed or random effect model we suggest the use of a test statistic of the same form. The test statistic is shown to have the same asymptotic null distribution as that for the balanced random effect model. The result is extended to the fixed or random effect models with covariates. The use of the test is illustrated in an example from animal breeding. Some optimality properties of the tests and open problems are discussed as well.
The effects of epinephrine administration on impedance cardiographic measures of cardiovascular function.

Abstract The effects of epinephrine administration on cardiovascular function were examined in 26 men who were given a bolus injection of either 1:10 000 epinephrine hydrochloride or physiological saline. Impedance cardiographic and continuous blood pressure measures were recorded during a 2-min pre-injection baseline and in the post-injection period. Compared to a saline control, epinephrine elicited greater shortening of heart period, pre-ejection period, and the R–B interval; greater increases in cardiac output, stroke volume, dZ/dt amplitude, Heather Index, and systolic and diastolic pressures; and greater decreases in total peripheral resistance (all P
Required relaxation: a method of inhibiting agitative-disruptive behavior of retardates.

Abstract Institutionalized retardates frequently exhibit agitative-disruptive behavior. Recent experiments have shown that overcorrective training in specific types of behavior can inhibit inappropriate behavior. A procedure was developed in which overcorrective practice in relaxation was given to each of eight adult retardates for their disruptions. The agitated resident was required to spend a fixed period of time in relaxation in his own bed upon each occurrence of agitation. This overcorrective relaxation resulted in a rapid, enduring and almost complete reduction in such behavior as self-injury, threats, physical aggression, screaming, crying, cursing and tantrums. Ward attendants strongly preferred the required relaxation procedure to the time-out technique and other inhibition procedures they had used. The procedure appears to be about as effective as alternative techniques and to have the advantages of ease of implementation and acceptability by ward staff and retardates as a ‘reasonable’ reaction to agitation.
Parish clergy and the aged: Examining stereotypes.

Hypotheses concerning clergymen's enjoyment of their pastoral contacts with older parishioners are examined using data from a national probability sample of 654 American Baptist parish ministers. The hypotheses test the ideas that ministers do not enjoy pastoral contacts with the elderly and that these contacts reflect the clergymen's ageist preferences and concern with instrumental over expressive values. The findings suggest that: (1) the majority of the clergy studied do not seem to have an aversion to ministering to older people; while not among the most enjoyable of their activities "ministering to the aged" clearly is not among the least enjoyable either; (2) there is some support for the view that clergy respond to the elderly in an ageist manner; comparing activities involving different age groups, the clergy prefer the young and adults to the aged; (3) those clergy who share with the elderly an interest in expressive activities are more likely to enjoy ministering to the aged.
Participation and Service Integration in Community-Based Initiatives

ABSTRACT Community-based initiatives (CBIs) attempt to link community participation with service integration to address a wide range of social issues. The promise of CBIs to provide more responsive and cost-effective social services has not been easy to realize. This “case story” illustrates the tensions between the founding principles of service integration and wider community participation. The author concludes that despite good theory, policy makers, social service professionals, and community activists must deal carefully with these natural dynamics to overcome the barriers to successful implementation of CBIs.
Evolution of bill size in relation to body size in toucans and hornbills (Aves: Piciformes and Bucerotiformes)

Evidence that the bill of the Toco Toucan, Ramphastos toco Statius Muller, 1776, has a specialized role in heat dissipation suggests a new function for the large and light-weight bill of the toucan family (Piciformes: Ramphastidae). A prediction of this hypothesis is that bill length in toucans will increase with body mass at a rate greater than the isometric expectation. This hypothesis was tested in a phylogenetic context with measurements of skeletal elements in adult males of 21 toucan species. In these species, 64.3% of variance in relative skeletal measurements was accounted for by the contrast between bill and body size. Maxilla length and depth increased with body mass at a greater than isometric rate relative to both body mass and other linear skeletal measures. By contrast, no such trend was seen in a parallel analysis of 24 hornbill species (Bucerotiformes), sometimes considered ecological equivalents of toucans. The unique relationship between bill size and body mass in toucans supports the hypothesis that the evolution of a heat dissipation function has been a persistent theme of bill evolution in toucans.
Live babies born per oocyte retrieved in a subpopulation of oocyte donors with repetitive reproductive success.

Objective To investigate the oocyte-to-baby rate when controlled ovarian stimulation was performed on a highly successful donor population and to evaluate whether they produce a higher proportion of reproductively competent oocytes compared with standard donors. Design Retrospective analysis of clinical and embryological database. Setting University center. Patient(s) A total of 191 oocyte donation cycles were analyzed from 53 donors (28 best-prognosis donors and 23 standard donors). Intervention(s) None. Main Outcome Measure(s) Total number of oocytes collected, the number of embryos transferable (fresh and frozen). and corresponding oocyte to live baby born (LBB) rates. In patients with remaining frozen embryos, the final LBB rate was estimated according to our reported rates. Result(s) A total of 130 oocyte retrievals from the best-prognosis donors yielded 2,470 oocytes. The total LBB per oocyte retrieved and LBB per embryo transferred was 7.3% and 24.6%, respectively. A total of 61 oocyte retrievals from the standard donors yielded 1,044 oocytes. The total LBB per oocyte and LBB per embryo transferred was 5.0% and 16.6%, respectively. This is significantly different from the best-prognosis donor group. Success rates were also analyzed after grouping donors based on the number of oocytes retrieved per cycle. In the best-prognosis group, the oocyte use rate increased significantly when fewer oocytes were retrieved, whereas the oocyte-to-baby rate was similar regardless of the number of oocytes for the standard donor group. Conclusion(s) This retrospective analysis revealed the existence of a subset of good-prognosis donors who produce a higher oocyte-to-baby rate that is indicative of a more biologically efficient reproductive system. Their identification, albeit a posteriori, has clinical implications for safety, by reducing ovarian hyperstimulation syndrome and multiple pregnancies, as well as for assisted reproductive technology success.
An R&D laboratory case study

A case was prepared for study at the 1979 Engineering Management Conference. It is presented along with the analysis of the conference study group with the thought that it might stimulate letters to the Editor with additional analysis and viewpoints.
Determination of traces of tellurium: Bismuthiol II as a reagent for tellurium

Abstract A speetrophotometric study of the new tellurium bismuthiol II reaction has been made to ascertain its suitability for the determination of traces of tellurium. The reaction mechanism is discussed. The yellow tellurium compound which is developed at pH 2.0–2.2 is stable, and is quantitatively extracted by chloroform at pH > 5. Addition of ammonium sulphate increases the rate of extraction. Two procedures, using aqueous solution with an absorption maximum at 395mμ, or solvent extraction with an absorption maximum at 335 mμ, are proposed. The extraction procedure makes the method more selective and sensitive. Many common ions do not interfere when EDTA and citrate are used as masking agents. The interferences from mercury, iron, copper, and selenium are serious. Beryllium or selenium may be used as collecting agents in the presence of EDTA for separation of tellurium. Selenium may subsequently be removed by volatilisation with bromine and hydrobromic acid. The absorptivity and sensitivity of the reaction were found to be 28,000 and 0.005 μg tellurium per cm 2 , respectively, at 335 mμ.
Optimal and Near–Optimal Solutions for Hard Compilation Problems

An optimizing compiler typically uses multiple program representations at different levels of program and performance abstractions in order to be able to perform transformations that – at least in the majority of cases – will lead to an overall improvement in program performance. The complexities of the program and performance abstractions used to formulate compiler optimization problems have to match the complexities of the high–level programming model and of the underlying target system. Scalable parallel systems typically have multi–level memory hierarchies and able to exploit coarse–grain and fine–grain parallelism. Most likely, future systems will have even deeper memory hierarchies and more granularities of parallelism. As a result, future compiler optimizations will have to use more and more complex, multi–level computation and performance models in order to keep up with the complexities of their future target systems. Most of the optimization problems encountered in highly optimizing compilers are already NP–hard, and there is little hope that most newly encountered optimization formulations will not be at least NP–hard as well. To face this "complexity crisis", new methods are needed to evaluate the benefits of a compiler optimization formulation. A crucial step in this evaluation process is to compute the optimal solution of the formulation. Using ad–hoc methods to compute optimal solutions to NP–complete problems may be prohibitively expensive. Recent improvements in mixed integer and 0–1 integer programming suggest that this technology may provide the key to efficient, optimal and near–optimal solutions to NP–complete compiler optimization problems. In fact, early results indicate that integer programming formulations may be efficient enough to be included in not only evaluation prototypes, but in production programming environments or even production compilers. This paper discusses the potential benefits of integer programming as a tool to deal with NP–complete compiler optimization formulations in compilers and programming environments.
Tanzanian Forest Edge Microclimatic Gradients: Dynamic Patterns1

Abstract Air temperature, vapor pressure deficit, and light intensity microclimatic gradients were examined along four forest edge and four paired forest interior transects in the East and West Usambara Mountains, Tanzania. Between 14 August 1995 and 11 August 1998, 287, 282, and 196 air temperature, vapor pressure deficit, and light intensity gradients, respectively, were measured along the four forest edge and four interior transects. The relationship between microclimate and distance from the forest edge was examined using piecewise linear regression. All microclimatic gradients were classified into one of nine shapes based on the sign and the size of the two estimated slopes. The relative frequency in the shapes of 65 percent of air temperature gradients, 52 percent of vapor pressure deficit gradients, and 62 percent of light intensity gradients along forest edge transects exceeded the relative frequency of these same shapes along forest interior transects, indicating that a majority of the forest edg...
Performance of automatic information systems

Abstract The SMART document retrieval system is used to investigate algorithms for text analysis and request searching. Results from three document collections indicate that word normalization is efficiently performed by automatic thesaurus lookup, while phrase matching procedures, statistical association methods, and concept hierarchies are useful for special applications. Automatic document clustering schemes and user-interactive feedback methods permit rapid searches of large collections. Abstracts are found to be superior to titles as a base for content analysis in a document retrieval system and almost as good as complete texts. Proper procedures for designing dictionaries and searching requests are discussed. The practicality of large scale document centers and their proper design are considered in light of these results.
Alternative Models of Spatial Competition

The concept of a spatial price equilibrium underlies most studies of spatial movement and competition. However, this concept is based upon a notion of perfectly competitive markets that is often unrealistic for many markets, such as the markets for oil and coal, and ignores the existence of local spatial monopolies. This paper presents alternative economic models of spatial competition and shows how all of these models can be solved with essentially the same solution algorithm. Specifically, after reformulating the classical spatial price equilibrium model and two extensions of Takayama and Judge's monopoly model, we state and analyze a Cournot-Nash model and discuss solution algorithms. We then generalize these models and algorithms to multiple commodities and networks with transshipment nodes. We conclude with a brief discussion of possible extensions of this class of models and associated algorithms.
A comparison of commercially available monoclonal antibodies for direct and indirect immunofluorescence culture confirmation and direct detection of parainfluenza viruses.

Abstract Two commercially available immunofluorescence monoclonal antibody (MAB) reagents (Bartels, Baxter Healthcare, Issaquah, WA; and Symex, Broken Arrow, OK) were evaluated as a means for detecting parainfluenza virus (PIV) both in shell-vial cultures and directly in clinical specimens. Bartels reagents are used in an indirect immunofluorescence assay (IFA) format and exist as MABs reactive with all three PIV serotypes, individually and in a pool. Symex reagents, also available individually and in a trivalent pool, are used in a direct immunofluorescence assay (DFA) format. Among a total of 299 respiratory specimens, 24 yielded PIV. In a shell-vial culture confirmation test, both the individual and pooled monoclonal antibody reagents from both Bartels and Symex detected all 24 PIV isolates. There were three apparent false-positive results with the Bartels pooled IFA reagents. Of the 299 specimens, 160 were also tested directly for the presence of PIV. There were 13 positive specimens among these 160. The Bartels and Symex monoclonal antibody reagents detected similar percentages of positive samples when used for direct detection (that is, 78.6–85.7). No false-positive results were obtained with any of the reagents in the direct-detection format.
Cell tracking using a distributed algorithm for 3-D image segmentation

We have developed and tested an automated method for simultaneous 3-D tracking of numerous, fluorescently-tagged cells. The procedure uses multiple thresholding to segment individual cells at a starting timepoint, and then iteratively applies a template-matching algorithm to locate a particular cell's position at subsequent timepoints. To speed up the method, we have developed a distributed implementation in which template matching is carried out in parallel on several different server machines. The distributed implementation showed a monotonic decrease in response time with increasing number of servers (up to 15 tested), demonstrating that the tracking algorithm is well suited to parallelization, and that nearly real-time performance could be expected on a parallel processor. Of four different template matching statistics tested for 3-D tracking of amoebae from the cellular slime mould Dictyostelium discoideum, we found that the automated procedure performed best when using a correlation statistic for matching. Using this statistic, the method achieved a 98.5% success rate in correctly identifying a cell from one time point to the next. This method is now being used regularly for 3-D tracking of normal and mutant cells of D. discoideum, and as such provides a means to quantify the motion of many cells within a three-dimensional tissue mass.
High-resolution 2-deoxyglucose autoradiography in quick-frozen slabs of neonatal rat olfactory bulb

Abstract We have used rapid freezing and freeze-substitution fixation to permit electron microscopic study of [3H]2-deoxyglycucose autoradiographs. The techniques minimize diffusion of label into processing fluids and, by inference, migration of label within tissue. Slabs of olfactory bulbs from 12-day-old rats were quick-frozen after one hour of exposure to physiological olfactory stimuli. In light microscopic autoradiographs at low magnification, the neuropil of individual olfactory glomeruli appeares uniformyly labeled with different levels by label clusters, suggesting greater deoxyglucose uptake by olfactory nerve terminals as compared with their postsynaptic dendrites. Periglomerular neurons were labeled differentially. Some microglia and glia precursor cells were heavily labeld in all bulbar laminae. The ultrastructure of cells and neuropil in all bulbar laminae was well-preserved. Cell processes and organelles could be identified in both stained sections and unstained electron microscopic autoradiographs. These experiments demonstrate the feasibility of combining quick-freezing with freeze substitution, in order to extend the resolution of studies using diffusable tracers such as 2-deoxyglucose. The results suggest that this is a promising method for assessing several controversies concerning deoxyglucose incorporation and neuronal and glial metabolism.
A unifying Clifford algebra formalism for relativistic fields

It is shown that a Clifford algebra formalism provides a unifying description of spin-0, -1/2, and-1 fields. Since the operators and operands are both expressed in terms of the same Clifford algebra, the formalism obtains some results which are considerably different from those of the standard formalisms for these fields. In particular, the conservation laws are obtained uniquely and unambiguously from the equations of motion in this formalism and do not suffer from the ambiguities and inconsistencies of the standard methods.
Auditory nerve responses to monophasic and biphasic electric stimuli.

Abstract Charge-balanced, biphasic stimulus pulses are commonly used in implantable cochlear prostheses as they can be safely delivered to living tissue. However, monophasic stimuli are more efficient (i.e. producing lower thresholds) and likely provide more spatially selective excitation of nerve fibers. We examined the neural responses to monophasic, ‘pseudomonophasic’, and biphasic stimuli to better understand the inherent tradeoffs of these stimuli. Using guinea pig and cat animal models, we compared the auditory nerve responses to both 40 μs monophasic and 40 μs/phase biphasic stimuli using both electrically evoked compound action potential and single-fiber recordings. We also made comparisons using a computational model of the feline auditory nerve fiber. In all cases, our stimuli were cathodic monophasic and cathodic-first biphasic pulses. As expected, monophasic stimuli provided lower thresholds relative to biphasic stimuli. They also evoked responses with relatively longer latencies. We also examined responses to charge-balanced biphasic pulses composed of two phases of differing duration (i.e. pseudomonophasic stimuli). The first phase was fixed at 40 μs, while the second phase was systematically varied from 40 to 4000 μs. With a relatively long second phase, we hypothesized that these stimuli would provide some of the beneficial features of monophasic stimuli. Both the gross-potential and single-fiber data confirmed this and indicate that the largest incremental effects of changing the second-phase duration occur for durations less than 500 μs. Consideration of single-fiber data and computer simulations suggest that these results are consistent with the neural membrane acting as a leaky integrator. The computer simulations also suggest that the integrative properties at least partially account for the difference between our monophasic–biphasic results and previously published data. Our results apply to cathodic-leading stimuli; due to differing patterns of membrane depolarization, they may not be applicable to situations using anodic-leading stimuli. Finally, we observed differences between the guinea pig and cat response patterns. Compared to cats, guinea pigs produced smaller monophasic vs. biphasic threshold differences. This interspecies disparity may be due to differences in cochlear anatomy.
Critical Magnetic Fields of Superconducting Ruthenium Isotopes and Search for an Isotope Effect

In order to investigate the isotope effect, i.e., the dependence of the superconducting transition temperature on the isotopic mass, the critical-magnetic-field curves of three samples of ruthenium have been measured to temperatures below 0.1\ifmmode^\circ\else\textdegree\fi{}K. The samples had mean isotopic masses of 99.2, 101.1 (natural), and 103.9. Detailed critical-magnetic-field curves were obtained, but no systematic dependence of the transition temperature on the mean isotopic mass was found. The transition temperature in zero external magnetic field characteristic of all three samples is ${T}_{0}=0.509\ifmmode\pm\else\textpm\fi{}0.002\ifmmode^\circ\else\textdegree\fi{}$K and the critical magnetic field at absolute zero is ${H}_{0}=70.0\ifmmode\pm\else\textpm\fi{}0.5$ G. Plots of the critical-field curves are given, as well as plots of ${H}_{c}$ versus ${T}^{2}$, which show deviations from parabolicity consistent with the weak-coupling limit of the BCS theory. Values for the electronic specific-heat coefficient $\ensuremath{\gamma}$ have been determined from the critical-field curves, and these give $\ensuremath{\gamma}\ensuremath{\simeq}2.80$ mJ/mole ${\mathrm{deg}}^{2}$. All three samples exhibited "ideal" or "Meissner" properties, that is, the transitions were reversible in a magnetic field.
Renal duplex sonography: main renal artery versus hilar analysis.

Abstract Objective: The purpose of this study was to compare the accuracy of main renal artery Doppler scanning interrogation and hilar analysis to diagnose hemodynamically significant renal artery disease. Methods: From January 1998 to August 1999, 41 patients had renal duplex sonography with both main renal artery interrogation and hilar analysis followed by angiography. They form the basis of this review. The sample consisted of 24 men and 17 women, with a mean age of 68.9 ± 10.2 years, who provided 80 kidneys for comparative analysis. Significant renal artery disease revealed through angiography was defined as ≥ 60% diameter-reducing stenosis or occlusion. Peak systolic velocity (PSV) (in meters per second) and the presence of poststenotic turbulence (PST) were determined from main renal artery interrogation. Acceleration time (AT) (in milliseconds) was measured by means of hilar analysis. Significant renal artery stenosis was defined by a PSV of 2.0 m/s or more and a PST or an AT more than 100 ms. Sensitivity analyses of both PSV and AT were examined, and 95% CIs were computed. Receiver operating characteristic curves were used to estimate optimal values for PSV and AT. Results: Angiography revealed hemodynamically significant fibromuscular dysplasia in 5 kidneys (4 patients), atherosclerotic stenosis ≥ 60% in 48 kidneys (30 patients), and renal artery occlusion in 4 kidneys (4 patients). Kidneys with significant renal artery stenosis had a higher PSV (2.54 ± 0.11 vs 1.28 ± 0.08, P P Conclusion: Main renal artery interrogation is an accurate screening test to detect significant stenosis or occlusion of the main renal artery. Hilar analysis alone does not provide sufficient sensitivity to be used as a sole screening study. Neither method detects the presence of renovascular disease associated with polar vessels. (J Vasc Surg 2000;32:462-71.)
DNA abasic lesions in a different light: solution structure of an endogenous topoisomerase II poison.

Topoisomerase II is the target for several anticancer drugs that “poison” the enzyme and convert it to a cellular toxin by increasing topoisomerase II-mediated DNA cleavage. In addition to these “exogenous topoisomerase II poisons,” DNA lesions such as abasic sites act as “endogenous poisons” of the enzyme. Drugs and lesions are believed to stimulate DNA scission by altering the structure of the double helix within the cleavage site of the enzyme. However, the structural alterations that enhance cleavage are unknown. Since abasic sites are an intrinsic part of the genetic material, they represent an attractive model to assess DNA distortions that lead to altered topoisomerase II function. Therefore, the structure of a double-stranded dodecamer containing a tetrahydrofuran apurinic lesion at the +2 position of a topoisomerase II DNA cleavage site was determined by NMR spectroscopy. Three major features distinguished the apurinic structure ( = 0.095) from that of wild-type ( = 0.077). First, loss of base st...
A polymer—microemulsion interaction: The coacervation model

A model which successfully predicts many of the qualitative features of the phase separation can be based upon the assumption that the microemulsion particle retains its integrity when diluted with external phase or when mixed with a polymer (which does not complex with the surfactants). In this case, the microemulsion particle behaves thermodynamically in a manner similar to a macromolecule so that one can predict that the polymer—microemulsion phase diagram will have qualitative similarities to that exhibited by the polymer—polymer2-solvent case. Most of the experiments were conducted by following the phase boundaries by measurements of the cloud points of the polymermicroemulsion mixtures. The cloud points of the mixtures were found to be (usually) linear functions of the weight fraction of the added polymer and decreased with increasing molecular weight. Plots of the logarithm of the slopes of these curves against the logarithm of the polymer molecular weight were linear, with a slope designated as β. The values for β for twenty-five systems studied fell within the narrow range of 0.55 ± 0.15. These values were seen to be the same as the Mark—Houwink exponents in the relationship between the intrinsic viscosity and the polymer molecular weight. The reason for this correspondence appears to be that the coacervation occurs at a polymer concentration about equal to the threshold overlap concentration. Ternary phase diagrams with microemulsion particles, brine, and polymer selected as pseudocomponents also exhibit many of the features predicted by the model. The phase boundary asymmetry is in the direction expected and asymptotes with the expected independence upon microemulsion and polymer molecular weights are also demonstrated. In agreement with the model, it is shown that the controlling variable is polymer weight average, rather than z or number average molecular weight.
Dynamic Adaption of Actin Stress Fibers in Response to Stretch

Actin stress fibers are mechanosensitive structural elements that respond to stretching to regulate cell morphology, stress fiber alignment, signal transduction and cell function. Adherent cells maintain a level of prestress largely dependent on myosin contractility, suggesting that stress fibers self-adjust to an equilibrium level of stress. Here a quantitative model is developed to describe a potential mechanism for fibers to re-establish stress equilibrum in response to changes in fiber length. The model involves dynamic changes in fiber reference length regulated by myosin-actin cross bridging, where the force-velocity relationship for individual sarcomeres is expressed as a hyperbolic Hill-type model. Under static conditions, the basal level of fiber tension and pre-extension are determined by the number of sarcomeres bundled together in the fiber and the stall force of the constituent myosin filaments. Following a step increase in fiber length, tension initially increases elastically, but then relaxes with a characteristic time constant dependent on the rate of myosin cross bridge dynamics. Returning the fiber to the original length results in a drop in tension below equilibrium, followed by a relatively rapid return to equilibrium.The model predicts that stress fibers respond to cyclic stretch in a manner dependent on frequency, ATP concentration, equilibrium sarcomere length, and sarcomere stiffness with relaxation times ranging from 0.02 to 0.8 sec based on model parameter values extracted from the literature. The modeling results are consistent with various experimental findings and provide molecular insight into how stress fibers determine and maintain mechanical equilibrium in response to changes in length.
Seed trait evaluation of Gossypium barbadense L. chromosomes/arms in a G. hirsutum L. background

Investigation of cotton nutritional components is important because its seeds provide a useful nutritional profile and can possibly serve as a biofuel resource. In this study, five cultivars, 13 cotton chromosome substitution (CS-B) lines, their donor parent, '3-79', and their recurrent parent, 'TM-1', were evaluated for seed traits over four environments. A mixed linear model approach with the jackknife method was employed to estimate variance components and to predict genotypic effects for each seed trait. Genotypic effects were more important than genotype by environment interaction for all seed traits. Chromosome associations with these seed traits were detected using the comparative method by comparing the differences between each CS-B line and TM-1. For example, chromosome 4 of 3-79 in TM-1 background was associated with reduced seed index (SI), embryo percentage, protein percentage while associated with increased seed oil percentage and seed fiber percentage. Other chromosome associations with these seed traits were also observed in this study. SI was highly correlated with three seed index traits: seed protein index, seed oil index (OI), and seed fiber index. Lint percentage, boll number, and lint yield were positively correlated with protein percentage while negatively correlated with SI and OI. SI and seed fiber content exhibited negative correlations with micronaire but positive correlations with fiber length and strength. Results suggested that agronomic traits and seed nutrition components can be improved simultaneously.