cssi/SciSciGPT-SciSciNet huggingface dataset:
Examination of Social Influence toward Need Satisfaction of High School Student-Athletes.

This study explored the independent and interactive effects of coach and peer influence on psychological need satisfaction (i.e., autonomy, competence, relatedness) among high school student-athletes from urban communities. Male and female student-athletes participating in high school sport (n = 136) completed a paper-pencil survey related to their perceptions of autonomy, competence, and relatedness, and the degree of social support received from their coaches and peers. Three hierarchical regression analyses for each psychological need were conducted. The greatest amount of variability in autonomy was predicted by coach autonomy support (R2 change = .275). The set of demographic variables (i.e., gender, race/ethnicity, socioeconomic status, type of sport) predicted the greatest amount of variability in competence (R2 change = .184). The largest amount of variability in relatedness was predicted by peer relatedness support (R2 change = .181). Among the three models, only relatedness was significantly predicted by the interaction of coach relatedness support and peer relatedness support (R2 change = .037, p = .003). This study sheds light on independent and interactive relationships among coaches and peers and their connections to need satisfaction.Subscribe to TPE
Probing shock geometry via the charge to mass ratio dependence of heavy ion spectra from multiple spacecraft observations of the 2013 November 4 event

In large Solar Energetic Particle (SEP) events, ions can be accelerated at coronal mass ejection (CME)-driven shocks to very high energies. The spectra of heavy ions in many large SEP events show features such as roll-overs or spectral breaks. In some events when the spectra are plotted in terms of energy/nucleon, they can be shifted relative to each other to make the spectral breaks align. The amount of shift is charge to mass ratio (Q/A) dependent and varies from event to event. This can be understood if the spectra of heavy ions are organized by the diffusion coefficients (Cohen et al. 2005). In the work of Li et al. (2009), the Q/A dependence of the scaling is related to shock geometry when the CME-driven shock is close to the Sun. For events where multiple in-situ spacecraft observations exist, one may expect that different spacecraft are connected to different portions of the CME-driven shock that have different shock geometries, therefore yielding different Q/A dependence. In this work, we examine one SEP event which occurred on 2013 November 4. We study the Q/A dependence of the energy scaling for heavy ion spectra using helium, oxygen and iron ions. Observations from STEREO-A, STEREO-B and ACE are examined. We find that the scalings are different for different spacecraft. We suggest that this is because ACE, STEREO-A and STEREO-B are connected to different parts of the shock that have different shock geometries. Our analysis indicates that studying the Q/A scaling of in-situ particle spectra can serve as a powerful tool to remotely examine the shock geometry for large SEP events.
Association of SARS-CoV-2 viral load at admission with in-hospital acute kidney injury: A retrospective cohort study.

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the associated Coronavirus Disease 2019 (COVID-19) is a public health emergency. Acute kidney injury (AKI) is a common complication in hospitalized patients with COVID-19 although mechanisms underlying AKI are yet unclear. There may be a direct effect of SARS-CoV-2 virus on the kidney; however, there is currently no data linking SARS-CoV-2 viral load (VL) to AKI. We explored the association of SARS-CoV-2 VL at admission to AKI in a large diverse cohort of hospitalized patients with COVID-19. Methods and findings We included patients hospitalized between March 13th and May 19th, 2020 with SARS-CoV-2 in a large academic healthcare system in New York City (N = 1,049) with available VL at admission quantified by real-time RT-PCR. We extracted clinical and outcome data from our institutional electronic health records (EHRs). AKI was defined by KDIGO guidelines. We fit a Fine-Gray competing risks model (with death as a competing risk) using demographics, comorbidities, admission severity scores, and log10 transformed VL as covariates and generated adjusted hazard ratios (aHR) and 95% Confidence Intervals (CIs). VL was associated with an increased risk of AKI (aHR = 1.04, 95% CI: 1.01-1.08, p = 0.02) with a 4% increased hazard for each log10 VL change. Patients with a viral load in the top 50th percentile had an increased adjusted hazard of 1.27 (95% CI: 1.02-1.58, p = 0.03) for AKI as compared to those in the bottom 50th percentile. Conclusions VL is weakly but significantly associated with in-hospital AKI after adjusting for confounders. This may indicate the role of VL in COVID-19 associated AKI. This data may inform future studies to discover the mechanistic basis of COVID-19 associated AKI.
Frequency Band Rejection Technique Based on the Operating Modes for a Wideband H-Shaped DRA

In this paper, a new approach to create frequency band rejection is applied to a wideband Hshaped dielectric resonator antenna (DRA). In order to create a notch characteristic in the operating band of the TEy1δ1 and TEy2δ1 modes, and guided by their theoretical and simulated electric field distributions, a narrow conductive strip is incorporated around the mid-section of the H-shaped DRA. The orientation of the notching strip is determined based on the electric field distribution of the selected modes for the frequency rejection. Furthermore, the selected feeding method improves the radiation patterns for this DRA shape compared to its previous designs. The new design offers an operating frequency range that extends from 4.15 to 9.8 GHz, allowing 81% of fractional bandwidth. The first notch is created at 6.5 GHz, while the second one is at 8 GHz. Average radiation efficiency of 95% across the frequency of interest is achieved with overall dimensions of 40×30×11.4 mm³. The proposed design is simulated using Ansys HFSS and validated by measurement.
High Incidence of Anterior Shoulder Pain in Young Athletes Undergoing Arthroscopic Posterior Labral Repair for Posterior Shoulder Instability.

Purpose The purposes of this study were to determine the incidence of anterior shoulder pain in young athletes undergoing arthroscopic posterior labral repair for symptomatic unidirectional posterior shoulder instability and in patients with preoperative anterior shoulder pain treated without biceps tenodesis at the time of arthroscopic posterior labral repair who underwent a revision biceps tenodesis procedure at short-term follow up. Methods A retrospective review was performed at a single institution over a 24-month period. The study included young patients who underwent an arthroscopic posterior labral repair for symptomatic unidirectional posterior shoulder instability. The electronic medical record, magnetic resonance arthrograms, and arthroscopic images were reviewed to exclude patients with posterior labral tears with anterior labral tear or SLAP (superior labrum anterior-to-posterior) tear extension on advanced imaging and arthroscopic examination. Data collected included the presence of preoperative tenderness to palpation of the biceps tendon in the groove, the results of a preoperative Speed test, postoperative Subjective Shoulder Value, the presence of postoperative anterior shoulder pain, and the need for a secondary biceps tenodesis. Results We identified 65 patients who underwent arthroscopic labral repair for posterior shoulder instability. From this cohort, 26 patients with symptomatic unidirectional posterior shoulder instability underwent an arthroscopic posterior labral repair. The incidence of preoperative anterior shoulder pain with Zone 2 biceps groove tenderness and a positive Speed test was identified in 20 of 26 patients (76.9%). Of 26 patients, 5 (19%) had concomitant biceps tenodesis. The median postoperative Subjective Shoulder Value was 80 (interquartile range, 60-90) at median follow-up of 2.1 years. Of the 20 patients with preoperative anterior shoulder pain, 8 of 20 (40%) reported persistent anterior pain. One patient (4.7%) underwent a secondary biceps tenodesis. Conclusions There is a high incidence of anterior shoulder pain and Zone 2 biceps groove tenderness in patients undergoing isolated arthroscopic posterior labral repair for unidirectional posterior shoulder instability. At short-term follow-up, few patients required a secondary biceps tenodesis procedure; however, 30% of patients had persistent anterior shoulder pain. Level of Evidence Level IV, retrospective diagnostic case series.
De/constructing literacies: considerations for engagement,: by Amélie Lemieux, New York, NY, Peter Lang Publishing, 2020, pp. 1–135, ISBN 978-1-4331-5609-0[AQ1]

Amelie Lemieux’s new book, De/Constructing Literacies: Considerations for Engagement, defines engagement in literacy studies through posthuman research. Broadly, posthuman research (Barad 2007; Bra...
A Review of single-effect solar absorption chillers and its perspective on Lebanese case

Abstract Solar cooling systems, specifically solar absorption cooling systems, are becoming an attractive subject since they are great alternatives to the conventional cooling systems which lead to high electrical consumption. In addition, this system can provide cooling without greenhouse gas emissions. Hence, many combinations of different components might be adopted to apply the solar absorption cooling system. This paper will discuss the absorption chiller working cycle, the absorption chiller working fluids, the solar collectors to be combined with solar cooling systems and the single-effect absorption chiller. Furthermore, the variation of the coefficient of performance, the solar fraction and the economic study will be discussed. The goal of this review is to present previous studies and analyze their results; highlight the environmental, energetic, and economic viability of such systems and tackle future challenges regarding solar absorption cooling system and discuss the application of this system on new climates and more specifically on Lebanon.
Disentangling the impact of alcohol use and hepatitis C on insulin action in Latino individuals.

BACKGROUND Alcohol, insulin resistance (IR), and hepatitis C (HCV) are all significant contributors to adverse outcomes of chronic liver disease. Latinos are disproportionately affected by these risk factors. We investigated the relationship between alcohol use and insulin action in a prospective cohort of Latino individuals with and without HCV. METHODS One hundred fifty-three nondiabetic Latino individuals (60 HCV+, 93 HCV-) underwent clinical evaluation and metabolic testing; 56 had repeat testing over a median follow-up of 1.5 years. Peripheral IR and hepatic IR were measured via steady-state plasma glucose (SSPG) and endogenous glucose production during a two-step, 240-min insulin suppression test. Insulin secretion (IS) was measured using the graded glucose infusion test. Alcohol use was categorized as none, moderate (≤1 drink/day for women and ≤2 drinks/day for men), and heavy (>moderate). Multivariable models including HCV status assessed associations of alcohol use with baseline SSPG, hepatic IR and IS, and changes in these parameters over time. RESULTS Overall, the median age was 44 years, 63.4% were male, 66.7% overweight/ obese, and 31.9% had heavy lifetime alcohol use while 60.4% had moderate lifetime alcohol use. SSPG and IS were similar by levels of alcohol use at baseline and alcohol use was not statistically significantly associated with change in these measures over time. However, lifetime daily heavy alcohol use (vs. not heavy, coef 2.4 μU-mg/kg-min-ml, p = 0.04) and HCV status (coef 4.4 μU-mg/kg-min-ml, p = 0.0003) were independently associated with higher baseline hepatic IR, and current heavy alcohol use was associated with greater change in hepatic IR in follow-up (coef 5.8 μU-mg/kg-min-ml, p = 0.03). CONCLUSIONS In this cohort of Latino individuals, lifetime and current heavy alcohol use influenced hepatic IR and its change over time. Strategies to decrease rates of heavy alcohol use or increase abstinence along with lifestyle modification and anti-HCV therapy to reduce metabolic risk are critical to prevent adverse liver and metabolic outcomes in Latino individuals.
On-Orbit and Ground Performance of the PGBA Plant Growth Facility

PGBA, a plant growth facility developed for commercial space biotechnology research, successfully grew a total of 30 plants (6 species) for 10 days on board the Space Shuttle Endeavour (STS-77) and is scheduled for reflight on board MSL-1 (STS-83) for a 16 day flight. The PGBA life support systems provide atmospheric, thermal, and humidity control as well as lighting and nutrient supply in a 23.6 liter chamber. Atmosphere treatment includes ethylene and other hydrocarbon removal, CO2 replenishment, and O2 control. The normally closed system uses controlled CO2 replenishment from the crew cabin as required by the plants. Temperature is controlled (1 C) at user-specified setpoints between 20-32 C, using water-filled coolant loops, solid state Peltier thermoelectric devices, and liquid heat exchangers. The thermoelectric cooling systems were optimized for low power consumption and high cooling efficiencies. Relative humidity is maintained between 60-100% using a cooled porous metal plate to remove water vapor from the air stream without cooling the bulk air below the dew point. The lighting system utilizes three compact fluorescent bi-axial lights with variable lighting control and light intensity (PAR) between 220 and 330 micromol/sq m/s at a distance of 20 cm in spaceflight configuration (on orbit power limited to 230 Watt for entire payload). A ground, up to 550 micromol/sq m/s light intensity can be achieved with 330 Watt payload power consumption. Plant water and nutrient support is sustained via the 'Nutrient Pack' system including the passive or active 'Water Replenishable Nutrient Pack.' The root matrix material (soil or Agar) and nutrient formulation of each pack is prepared according to plant species and experimental requirements. These systems were designed by NASA Ames personnel. Data acquisition and control systems provide 32 channels of environmental data as well as digitized or analog video signals for downlink.
Decomposing Hindsight Bias

Traditional accounts of “hindsight bias” inadequately distinguish “primary” hindsight bias from both “secondary” and “tertiary” hindsight bias. A subject exhibits primary bias when she assigns a higher ex ante probability estimate to actual outcomes, secondary bias when she believes that she herself would have made the same estimate of the prior probability of an event before receiving outcome information as she made after receiving it, and tertiary bias when she believes that third parties lacking outcome information were unreasonable if they did not make the same prior probability judgments that subjects now possessing such information make.
The materials dosimetry reference facility

A new, high-intensity reference neutron field for reactor dosimetry is in the early stages of operation at the Ford Nuclear Reactor (FNR) at the University of Michigan. Designed and constructed by the National Institute of Standards and Technology (NIST), the facility hosts calibration and validation experiments in support of materials neutron dosimetry for the nuclear power industry and for the metallurgical community engaged in estimating radiation damage in steel. This benchmark is a natural extension of a long-term NIST program to develop standard and reference neutron fields for measurement assurance applications and for testing new detectors and techniques. Field characterization and user operation of the facility is a joint effort by NIST and the Phoenix Memorial Laboratory of the University of Michigan. The materials dosimetry reference facility (NDRF) complements the [sup 235]U cavity fission source at NIST by providing a tenfold increase in fast-neutron fluence, a much larger irradiation volume with modest flux gradients and a neutron spectrum rich in intermediate-energy neutrons. Two spectrum options are available to investigate detector response characteristics and to validate the interpretation of dosimetry measurements.
Oligomerization and higher‐order assembly contribute to sub‐cellular localization of a bacterial scaffold

In Caulobacter crescentus, the PopZ polar scaffold protein supports asymmetric cell division by recruiting distinct sets of binding partners to opposite cell poles. To understand how polar organizing centres are established by PopZ, we investigated a set of mutated PopZ proteins for defects in sub-cellular localization and recruitment activity. We identified a domain within the C-terminal 76 amino acids that is necessary and sufficient for accumulation as a single subcellular focus, a domain within the N-terminal 23 amino acids that is necessary for bipolar targeting, and a linker domain between these localization determinants that tolerates large variation. Mutations that inhibited dynamic PopZ localization inhibited the recruitment of other factors to cell poles. Mutations in the C-terminal domain also blocked discrete steps in the assembly of higher-order structures. Biophysical analysis of purified wild type and assembly defective mutant proteins indicates that PopZ self-associates into an elongated trimer, which readily forms a dimer of trimers through lateral contact. The final six amino acids of PopZ are necessary for connecting the hexamers into filaments, and these structures are important for sub-cellular localization. Thus, PopZ undergoes multiple orders of self-assembly, and the formation of an interconnected superstructure is a key feature of polar organization in Caulobacter.
Factoring in ℚ[x], I

In Chapters 14 and 15 we looked at polynomials with real or complex coefficients. We completely determined the irreducible polynomials, and showed how to make a start at locating the roots of a real polynomial. In this chapter we begin considering the same questions for polynomials with coefficients in ℚ, the field of rational numbers. Here the situation is much different from the situation over ℝ or ℂ. Over ℚ there are many irreducible polynomials of any degree, and determining which polynomials are irreducible is difficult, compared to the real or complex case. On the other hand, finding roots (and therefore irreducible factors of degree 1) of a polynomial in ℚ [x] is easy, and we will eventually give two different explicit procedures for determining the complete factorization of any polynomial with rational coefficients in a finite number of steps.
Conventional Wisdom? The Effect of Nuclear Proliferation on Armed Conflict, 1945-2001

The possession of nuclear weapons confers many benefits on a state. The path to proliferation, however, is often violent. When a state initiates a nuclear weapons program, it signals its intent to fundamentally alter its bargaining environment. States that once had an advantage will now be disadvantaged. This change in the environment is not instantaneous, but evolves slowly over time. This gives states both opportunities and incentives to resolve underlying grievances, by force if necessary, before a nuclear weapons program is completed. Our cross-national analyses of nuclear weapons program and the onset of militarized conflict confirm this expectation. In particular, the closer a state gets to acquiring nuclear weapons, the greater the risk it will be attacked (especially over territorial issues). Once nuclear weapons are acquired, however, the risk of being attacked dramatically drops, though not below the risk of attack for non-proliferators.
Placing the River in Context: James C. Knox, Fluvial Geomorphology, and Physical Geography

We characterize the fluvial geomorphology research of James C. Knox by considering five of his scholarly papers, selected to illustrate not only some of Knox’s methods and results but also his conviction that stream-sediment interactions are intricately connected to a range of environmental variables reflecting the scope of physical geography. Those variables, as we discuss, included hydrology, climate, vegetation, position in the drainage network, and human land use. We conclude with the suggestion that Knox’s breadth of geomorphic vision was echoed in his approach to his own academic career, and his belief that academic institutions are best served by broad and integrative perspectives.
Music Perception of Cochlear Implant Recipients with Implications for Music Instruction: A Review of the Literature.

This review of the literature presents a systematic analysis of the capabilities and limitations of cochlear implant (CI) recipients with regard to music perception. Specifically, it (a) analyzes i...
Locating and estimating the areal extent of wildfires in alaskan boreal forests using multiple-season AVHRR NDVI composite data

Abstract Techniques to locate and estimate the aroas of fires in the boreal forests of Alaska using satellite imagery from the Advanced Very High Resolution Radiometer (AVHRR) are described. The basis for these techniques is the normalized difference vegetation index (NDVI) derived from the AVHRR data, which is reduced by the damage to the plant canopy during fires. AVHRR data collected during three years (1990, 1991, and 1992) were analyzed in order to determine the locations and estimate the areal extent of fires that occurred in 1990 and 1991 (when 2 million ha of land in Alaska were affected by fire). Fires in Alaska tend to take place in large events, with > 96% of the total area burned occurring in fires greater than 20,000 ha in size. The analysis techniques developed in this paper resulted in detection of > 83% of all fires > 20,000 ha in size over the two years, and detected > 78% of the area burned in the state during this time period.
Isoperimetric inequalities for the energy of uniform-vorticity flows in channels of uniform width

We prove several isoperimetric inequalities involving the kinetic energy of constant-vorticity flows through channels of uniform width.
GENDER ROLES AND FEMALE CRIMINALITY Some Critical Comments

This paper investigates the recent claim that women are becoming increasingly involved in aggressive or serious criminal activities. On the basis of an a priori classification of aggressive crimes, a review of three different types of data reveals no unambiguous pattern of change in women's criminality. Several theoretical problems which hove inhibited the systematic development of the relationships between gender roles and criminality are discussed. Particular attention is paid to the lack of conceptual precision that characterizes the use of the terms gender and aggressive crime.
Immigrant assimilation into US prisons, 1900–1930

The analysis of a new dataset on state prisoners in the 1900 to 1930 censuses reveals that immigrants rapidly assimilated to native incarceration patterns. One feature of these data is that the second generation can be identified, allowing direct analysis of this group and allowing their exclusion from calculations of comparison rates for the “native” population. Although adult new arrivals were less likely than natives to be incarcerated, this likelihood was increasing with their years in the USA. The foreign born who arrived as children and second-generation immigrants had slightly higher rates of incarceration than natives of native parentage, but these differences disappear after controlling for nativity differences in urbanicity and occupational status. Finally, while the incarceration rates of new arrivals differ significantly by source country, patterns of assimilation are very similar.
Abundance and distribution of desert annuals: are spatial and temporal patterns related?

Summary 1 Spatial distribution–abundance relationships have been intensively studied. Workers have now begun to study temporal relationships but little is known about how these are related to spatial patterns. We examined these relationships both over space and time using 15 years of data from permanent quadrats in the Chihuahuan Desert. 2 Winter and summer annual communities were analysed. Within single years, the species in each community exhibited a positive relationship between distribution and abundance at two spatial scales, 0.25-ha plots and 0.25-m2 quadrats. Over 15 years, the species in each community also exhibited a positive relationship between abundance and the number of years in which they were present. Species frequency distributions, both in space and over time, were scale-dependent. 3 Over space, the frequency distribution was bimodal at large (plot) scales, but unimodal at small (quadrat) scales in both communities. Over time, the frequency distribution was bimodal for winter annuals but unimodal for summer annuals, a difference we attribute to the marked difference between the two communities in the temporal consistency of rank abundance of species. We conclude that both niche and metapopulation models can be used in explaining the distribution patterns of species but at different scales. The factors and processes in these models are not mutually exclusive in determining the overall abundance and distributions of these species in space and over time.
Drainage basin peak discharge rating curve

The stream gauge rating curve for a drainage basin can be transformed into a drainage basin peak discharge rating curve that is more stable than the rating curve from which it is derived. The resulting drainage basin peak discharge rating curve can be used to predict peak discharge, identify anomalous discharges caused by channel obstructions or other causes, evaluate the effect of flood retarding structures, and evaluate historical records. The drainage basin peak discharge rating curve is valid for drainage basins of any size, for any discharge up to the time of concentration, and for snowmelt.
From Gatekeeping to Engagement: A Multicontextual, Mixed Method Study of Student Academic Engagement in Introductory STEM Courses

The lack of academic engagement in introductory science courses is considered by some to be a primary reason why students switch out of science majors. This study employed a sequential, explanatory mixed methods approach to provide a richer understanding of the relationship between student engagement and introductory science instruction. Quantitative survey data were drawn from 2,873 students within 73 introductory science, technology, engineering, and mathematics (STEM) courses across 15 colleges and universities, and qualitative data were collected from 41 student focus groups at eight of these institutions. The findings indicate that students tended to be more engaged in courses where the instructor consistently signaled an openness to student questions and recognizes her/his role in helping students succeed. Likewise, students who reported feeling comfortable asking questions in class, seeking out tutoring, attending supplemental instruction sessions, and collaborating with other students in the course were also more likely to be engaged. Instructional implications for improving students' levels of academic engagement are discussed.
New risk-consequence rockfall hazard rating system for Missouri highways using digital image analysis

The Missouri Rockfall Hazard Rating System (MORFH RS) is a new scheme for rating rockfall hazards along the roads of the Missouri State highway system. Existing rating systems used in other jurisdictions focus on the risk of failure and ignore the consequence of failure, or they lump the ratings for risk and consequence together. Missouri highway rock cuts tend to have low heights but are typically highly weathered, with special problems from karst and paleokarst. In MORFH RS, risk and consequence factors are given equal weight but isolated from each other. MORFH RS utilizes two phases: 1) identification of the most potentially problematic rock cuts using mobile digital video logging; 2) characterization and prioritization of remediation for the potentially problematic rock cuts identified in phase 1, using MORFH RS. In phase 2 four types of parameters are evaluated: 1) parameters that can be measured on computer scaled video images; 2) parameters which are descriptive, and need field evaluation; 3) parameters which are obtained from MODOT records; 4) conditional parameters which are evaluated under specific conditions. Only those parameters were selected that were deemed meaningful and/or relatively easy to measure or estimate. Parameters were assigned to either a risk or consequence category or both. MORFH RS has been tested on sections of Missouri highways. About 300 rock cuts were evaluated and used to prepare, modify, test, and verify the system. Sensitivity analysis of the system was done by quantifying potential errors in the video measurements and by a rating comparison of 12 MODOT and University of Missouri-Rolla (UMR) personnel on 10 rock cuts along Highway 63.
Description of the leukocyte function-associated antigen 1 (LFA-1 or CD11a) promoter.

Abstract The CD11a/CD18 (leukocyte function-associated antigen 1 or LFA-1) leukocyte integrin is expressed at high levels on the cell surface of T lymphocytes and macrophages, where it mediates homotypic and heterotypic adherence between leukocytes and other cell types by binding to intracellular adhesion molecules 1 and 2 on the conjugate cell. To initiate studies of the molecular regulation of expression of the CD11a molecule, we isolated genomic clones corresponding to the 5'-flanking region of CD11a, identified the transcriptional start sites for CD11a, and characterized the CD11a promoter sequence in transient expression assays. The CD11a promoter (1.7 kb) directed functional activity of a heterologous reporter gene in the T-lymphocyte cell line Jurkat and the myeloid cell line HL-60 but did not direct functional activity in three different nonleukocyte cell lines. Deletional analysis of the CD11a promoter sequence indicated the presence of distinct, cell-type-specific regulatory sequences with the region from -40 to -17 relative to the transcription start sites responsible for most of the in vitro activity of the CD11a promoter in the Jurkat T-cell line, and the promoter sequence located within the first 17 bp relative to the transcription start sites responsible for CD11a promoter activity in the HL-60 cell line. Identification of the CD11a promoter provides the opportunity to identify unique cis-acting elements and trans-acting factors responsible for the cell-type-specific expression of CD11a in human leukocytes. Further, the CD11a promoter may be useful in transgenic constructs and in retroviral vectors to direct expression of heterologous genes selectively in leukocytes.
Simulation of the Cold-Wall Swirl Driven Combustion Chamber

This study provides the numerical simulation of an innovative, cold-wall bidirectional vortex combustion chamber (CWBVCC). The vortex flow configuration in this chamber is unique in that the oxidizer is typically injected tangentially into the combustion chamber, and the process results in a swirling combustion field that inherently separates into two distinct coaxial zones: an outer vortex stream circulating towards the head end and an inner concentric vortex spiraling in the opposite direction. The inner swirl increases fuel residence time, turbulence, and propellant mixing, thus improving overall efficiency and thrust. The spinning vortices also provide an extended flow path much longer than the geometric length of the chamber, thus allowing for shorter chamber lengths. The outer vortex protects the chamber walls from excessive heating loads via convective cooling, thus resulting in lower wall temperatures. This feature not only reduces cooling requirements, but also permits more flexibility in material selection that can ensure durability and reduced weight. Through the cold flow simulation, the existence of a bi-directional flow is demonstrated and the spatial invariance of the so-called mantle (that separates inner and outer vortex regions) is confirmed. According to these simulations, the cold wall effect is extrapolated from the temperature maps and species mass fractions distributed over the combustion chamber. Our simulations further indicate that the oxidizer flow entering the chamber does not short circuit toward the nozzle but is rather compelled to spiral toward the head end where fuel is supplied through radial injectors. The need for secondary oxidizer injection at the head end is found to be instrumental under reactive flow conditions.
The Influence of Exposure Variability on Dose-Response Relationships

Abstract A conceptual model is presented which ties together the distributions of exposure, dose, damage, and risk of disease from airborne toxic agents. The input to the model is a series of daily exposures described by a lognormal distribution function. The output is the distribution of risks to a discrete population of uniformly-exposed workers. Two points are made with reference to the influence of exposure variability on the model. First, it is important to differentiate between the variability of air levels associated with a particular job and that associated with individual work practices. Analysis of variance techniques can be used in this context. Second, the importance of exposure variability as a determinant of hazard can be inferred from the particular linkages between the distributions of exposure, dose, and damage for a particular toxicant. When the chemical is slowly eliminated from the target organ, for example, the dose becomes very great relative to the daily input and fluctuations in exposure from day to day are dampened at the site of damage. Both of these points are illustrated for inorganic lead with published exposure data and a toxicokinetic model.
Properties of a two-axis spectrometer as a slow neutron monochromator

Abstract Presented are the performance characteristics of a 2-axis neutron monochromator used for total cross section measurements. The intensity, resolution, and beam purity of the instrument are compared to those of a single-axis monochromator. The first and second axis rocking curves are used as an indirect check of the instrument resolution. It is found that the two-axis monochromator is capable of significantly better energy resolution compared to that of a single-axis instrument give the same intensity requirements.
Cell proliferation, migration, and specialization in the epithelium of the mouse tongue

The three dimensional structure of the filiform papilla of the mouse tongue is presented. Two distinctly different keratinized cell products are found in the region of the filiform papilla. Evidence for the existence of the two cell types is based on a series of histological, cytological, micro-manipulative and cell migration studies. A study of the tongues of embryonic and adult mice shows no morphological evidence of heterogeneity in the cells of the basal layer of epithelium which supports the concept that the two different keratinized cell products derive from a homogeneous cell population. Tritiated thymidine autoradiographic studies reveal that the proliferative pool of epithelial cells is limited to the basal cell layer. The avergae cell renewal rate of this layer is presented for the various parts of the tongue. The progenitor cell cycle is also described. The studies indicate that the movement of a cell from the basal layer to the spinous layer is a random event in time and that the movement of a cell out of the basal layer precludes further cell proliferation by that cell. The results indicate that it is positional chance at the time of cell birth which determines whether a cell will specialize into one of two different alternate fates. The fate of the cell in this particular case is based on the particular micro-environment the cell is forced to occupy. The force is provided by the growth of cellular mass and the subsequent crowding out of those cells not able to remain attached to the basement membrane.
Structure-function analyses of isochorismate-pyruvate lyase from Pseudomonas aeruginosa suggest differing catalytic mechanisms for the two pericyclic reactions of this bifunctional enzyme.

The isochorismate-pyruvate lyase from Pseudomonas aeruginosa (PchB) catalyzes two pericyclic reactions in a single active site. PchB physiologically produces salicylate and pyruvate from isochorism...
Srinivasa Ramanujan (1887‐1920) A centennial tribute

This centennial tribute commemorates Ramanujan the man and Ramanujan the mathematician. A brief account of his remarkable mathematical contributions is presented to describe the great talent of Srinivasa Ramanujan. Considerable discussion is made of his new and important ideas, results and theorems in various subjects including definite integrals, hypergeometric series, Bernoulli and Euler numbers, the Riemann zeta function, distribution of prime numbers, theory of partitions and statistical mechanics, continued fractions, hypergeometric functions, Rogers‐Ramanujan identities, theory of representation of numbers as sums of squares, Ramanujan's τ‐function, q‐series, elliptic and modular functions.
Multimaterial preform coextrusion for robust chalcogenide optical fibers and tapers

The development of robust infrared fibers is crucial for harnessing the capabilities of new mid-infrared lasers. We present a novel approach to the fabrication of chalcogenide glass fiber preforms: one-step multimaterial extrusion. The preform consists of a glass core and cladding surrounded by a built-in, thermally compatible, polymer jacket for mechanical support. Using this approach we extrude several preform structures and draw them into robust composite fibers. Furthermore, the polymer cladding allows us to produce robust tapers with submicrometer core diameter.
Corrections to nucleon spin structure asymmetries measured on nuclear polarized targets

The nucleon spin structure functions have been extracted from measurements of asymmetries in deep inelastic scattering of polarized leptons on polarized nuclei. The polarized nuclei present in practical targets: H, ${}^{2}\mathrm{H},$ ${}^{3}\mathrm{He},$ ${}^{14}\mathrm{N},$ ${}^{15}\mathrm{N},$ ${}^{6}\mathrm{Li},$ and ${}^{7}\mathrm{Li},$ are, with the exception of hydrogen, systems of bound nucleons, some of which can attain significant degrees of alignment. All the aligned nucleons contribute to the asymmetries. The contributions of each nuclear species to the asymmetry have to be carefully determined, before a reliable value for the net nucleon asymmetry is obtained. For this purpose, the spin component of the nuclear angular momentum for every nuclear state and the probability of each state have to be known with sufficient accuracy. In this paper I discuss the basic corrections used to estimate the contributions of the different nuclei, with emphasis on the $A=6$ and 7 Li isotopes present in the ${\mathrm{Li}}^{2}\mathrm{H}$ polarized target used during SLAC Experiment 155 to study the deuteron spin structure.
Regularity of the solution of Hammerstein equations with weakly singular kernel

Some regularity properties of the solution to a class of weakly singular Hammerstein equations are derived. The results obtained in this paper extend the results of C. Schneider [4], where he obtains similar properties for the solution to weakly singular Fredholm equations of the second kind.
Equal sums of sixth powers

Abstract The problem of solving x 6 + y 6 + z 6 = u 6 + v 6 + w 6 , subject to certain auxiliary conditions, is reduced to a single cubic. In this way some earlier known solutions are inserted into an infinite cyclic group lying on the cubic.
Impact of Ramped Vanes on Normal Shock Boundary Layer Interaction

Large-eddy simulations of a vortex generator embedded upstream of a normal shock boundary-layer interaction followed by a subsonic diffuser were conducted. In particular, the “ramped-vane” flow control devicewas placed in a supersonic boundary layer with a freestream Mach number of 1.3 and a Reynolds number of 2400 based on momentum thickness. The ramped vane had a height of 0:52 and generated strong streamwise vorticity that entrained the high-momentum flow to the near-wall region. This contributed to decreasing the shock-induced flow separation while significantly increasing the skin friction coefficient in the diffuser where a strong adverse pressure gradient was present. In addition, it was found that the high-momentum flow persisted far downstream of the shock interaction region, which yielded reductions of both the displacement thickness and the shape factors compared to the uncontrolled case.
Elasticity of α-helical coiled coils

Predicting large scale conformations of protein structures is computationally demanding. Here we compute the conformation and elasticity of double-stranded coiled coils using a simple coarse-grained elastic model. By maximizing the contact between hydrophobic residues and minimizing the elastic energy, we show that the minimum energy structure of a coiled coil is a supercoiled double helix of alpha helices. For realistic binding energies, the elastic energy of the alpha helices requires binding every 7th residue, which leads to a pitch and helix angle for the structure that is consistent with experimental measurements. Analysis of the model equations shows how the pitch varies with the helical repeat of the hydrophobic residues and with the ratio of the twisting modulus to the bending modulus and provides an estimate of the persistence length of around 150 nm, in agreement with previous experimental estimates.
Simulation of Slow Variable-Angle Spinning NMR Spectra. Application to13C Bonded to N

Abstract Simulations of NMR spectra for spin- 1 2 nuclei in rigid solids spun at relatively slow speeds and at angles other than the magic angle are presented. Particular emphasis is on the case where13C is bonded to a quadrupolar nucleus such as14N. The feasibility of quantitatively extracting the chemical-shift tensor, bond lengths through the dipolar interaction, and the electric-field gradient of the neighboring nucleus from a single (1-D) spectrum is demonstrated. The sensitivity of the observed changes in the spectra to changes in the physical and experimental parameters is discussed and illustrated using nitrile13C spectra of solid CH3CN. Equations are derived to extend the theory beyond the adiabatic approximation.
Management of Obstructive Sleep Apnea in Adults

Qaseem and colleagues’ clinical practice guidelineon obstructive sleep apnea (OSA) (1) states, “no randomized trialsevaluated the long-term clinical outcomes of [continuous positiveairway pressure (CPAP)] use, such as death or cardiovascular illness,and evidence showing the effect of CPAP on quality of life wasinconsistent and therefore inconclusive.” Nevertheless, the guidelinestrongly recommends CPAP as initial therapy for OSA.We agree that surgery is usually used after CPAP failure but dis-agree that “[c]urrent evidence evaluating surgery was limited and insuf-ﬁcient to show the beneﬁts of surgery for OSA.” This statement contrastswith their recommendation of CPAP despite its similar evidence limitations.Further, the Agency for Healthcare Research and Quality’scomparative effectiveness review states that there is “insufﬁcient
Cover Picture: Enhanced Electro‐Optic Behavior for Shaped Polymer Cholesteric Liquid‐Crystal Flakes Made Using Soft Lithography (Adv. Funct. Mater. 2/2005)

The cover shows a variety of shaped flakes fabricated from polymer cholesteric liquid-crystal material using soft lithography. In work reported by Jacobs and co-workers on p. 217, the micrometer-sized flakes exhibit brilliant circularly polarized selective reflection colors without polarizers or color filters when placed in a fluid-filled electro-optic cell. With the application of a low-magnitude alternating current field, the flakes reorient in hundreds of milliseconds and the colors disappear. Polymer cholesteric liquid-crystal (PCLC) flakes were investigated for their electro-optical behavior under an applied alternating-current field. Shaped flakes, fabricated using soft lithography and suspended in dielectric-fluid-filled cells, reoriented more uniformly than randomly shaped flakes made by fracturing of PCLC films. Extensive characterization found shaped flakes to be smooth and uniform in size, shape, and thickness. Reorientation in applied fields as low as tens of mVrms μm–1 was fastest for flakes with lateral aspect ratios greater than 1:1, confirming theoretical predictions based on Maxwell–Wagner polarization. Brilliant reflective colors and inherent polarization make shaped PCLC flakes of interest for particle displays.
Staining and fluorescence-activated cell sorter analysis of human lymphocytes using antibodies to a short, chemically synthesized human IL-2 peptide☆

Abstract A rabbit antibody against a chemically synthesized peptide (p84), encompassing residues 59–72 of mature human interleukin 2 (IL-2), has been shown to react specifically with natural or recombinant IL-2. This antibody was used in immunoperoxidase and immunofluorescence techniques for identification of IL-2-containing cells in human peripheral blood or tonsils. Lymphocytes were stimulated with T-cell mitogens (PHA, PWM), fixed, and incubated with affinity-purified anti-p84 antibody, followed by appropriately conjugated secondary antibodies. FACS analysis demonstrated a low fluorescence intensity in 5 to 15% of unstimulated cells. In contrast, 40–60% of mitogen-stimulated cells were stained at a high fluorescence intensity. Staining was inhibited by preincubating the anti-p84 antibody with the homologous peptide or recombinant IL-2, but not by unrelated peptides. In immunoperoxidase staining, anti-p84 antibody reacted selectively with an enriched T-cell population which was 95% Leu 5 + , 80% Leu 3 + , and 60% Tac + . Thus, this antibody to a synthetic IL-2 peptide reacts selectively with activated T cells, and may serve, therefore, as a useful tool for visualization and enumeration of IL-2-containing cells in blood and tissues.
Modeling of bubble coalescence in bubbly co-current flows restricted by confined geometry

Principles of kinetic theory are used to model the coalescence of bubbles in horizontal and vertical upflows where bubble movements are restricted by channel geometry. There are four critical variables that determine the rate at which a swarm of small bubbles will coalesce: the initial bubble population, the average initial bubble diameter, the average relative velocity of the bubbles, and the efficiency of bubble collisions. A model based on dimensional considerations is proposed to predict bubble size as a function of flow position. This model agrees well with experimental results for air/water and air/water/glycerin systems performed in a rectangular channel with an aspect ratio of 12.5 and a cross-sectional area of 2cm2 under both vertical and horizontal orientations.