cssi/SciSciGPT-SciSciNet huggingface dataset:
Random testing and model checking: building a common framework for nondeterministic exploration

Two popular forms of dynamic analysis, random testing and explicit-state software model checking, are perhaps best viewed as search strategies for exploring the state spaces introduced by nondeterminism in program inputs. We present an approach that enables this nondeterminism to be expressed in the SPIN model checker's PROMELA language, and then lets users generate either model checkers or random testers from a single harness for a tested C program. Our approach makes it easy to compare model checking and random testing for models with precisely the same input ranges and probabilities and allows us to mix random testing with model checking's exhaustive exploration of non-determinism. The PROMELA language, as intended in its design, serves as a convenient notation for expressing nondeterminism and mixing random choices with nondeterministic choices. We present and discuss a comparison of random testing and model checking. The results derive from using our framework to test a C program with an effectively infinite state space, a module in JPL's next Mars rover mission. More generally, we show how the ability of the SPIN model checker to call C code can be used to extend SPIN's features, and hope to inspire others to use the same methods to implement dynamic analyses that can make use of efficient state storage, matching, and backtracking.
Organosilatrane building blocks

Abstract Phenylsilatrane analogues containing reactive amino, bromo, boronic ester, and alkynyl functional groups for coupling reactions have been prepared. Pinacol boronic ester and ethynyl analogues were synthesized from 4-bromophenylsilatrane by palladium catalyzed reactions. The silatrane functional group was shown to be stable during the palladium catalysis procedures and silica-gel purification, making the molecules amenable to further synthetic manipulation. The described phenylsilatranes are useful building blocks for forming more complex organosilatrane species.
Management practices to reduce lodging and maximize grain yield and protein content of fall-sown irrigated hard red spring wheat

Abstract Management practices which reduce lodging and increase grain protein concentration were studied in two short-statures wheat (Triticum aestivum L.) cultivars in four high-yielding environments in northern California. Management factors included planting densities of 200, 300, and 400 seeds m−2 with the plant growth regulator ethephon [ (2-chloroethyl) phosphonic acid] (0.56 kg a.i. ha−1) to suppress lodging, and nitrogen topdressing (45 kg N ha−1) at anthesis in conjunction with an irrigation for increased grain protein content. The hard red spring wheat cultivars, Serra and Yolo, which differ in grain quality characteristics and relative susceptibility to lodging and some foliar diseases, were used. Ethephon did not provide complete lodging control, but reduced plant height, delayed the onset of severe lodging until later stages of grain-fill, and increased grain yield by 5–21% depending on cultivar and lodging severity. Height reduction due to ethephon was expressed as reduced length of the peduncle and upper internodes. Ethephon was more effective on Serra, the more lodging-susceptible cultivar, increasing grain yield of Serra by more than 1200 kg ha−1 in one experiment. In most cases, yield response to increased planting density was nonsignificant due to increased lodging at the higher densities and to compensation by yield components (increased spike number plant−1 and kernel number spike−1) at lower densities. Nitrogen topdressing at anthesis caused grain protein content to be increased by 1.6 to 7.4% with differences depending largely on the level of N fertilizer supplied prior to anthesis and residual N fertility from previous crops. Although increases in grain protein content due to N topdressing at anthesis were small, grain protein, and thus grain quality were increased without increasing lodging. Management practices which include reduced planting density, ethephon application, and N topdressing at anthesis followed by irrigation, should be considered in wheat production environments where lodging and low grain protein concentration are expected to occur.
Versatile One‐Piece Total Artificial Heart for Bridge to Transplantation or Permanent Heart Replacement

: A versatile, one-piece total artificial heart (TAH) system that can be driven by either an electromechanical acutator (EM-TAH) or a pneumatic source (P-TAH) has been developed. The common units for both TAHs are the conically shaped left and right pusher-plate-type pumps (63 ml SV) that sandwich a thin centerpiece (18 mm) having a respective actuator. The EM actuator, mounted in the middle of the centerpiece, consists of a direct-current brushless motor and a roller screw while the pneumatic actuator consists of a low-pressure air source. The outer diameter of the pumping unit is 97 mm with its central thickness being 82 mm; overall volume is 510 cc. The TAH is operated in the left master alternative ejection mode with the left pump fill signal. High-flex-life Hexsyn rubber is used as the diaphragm, and the blood-contacting surface is coated with dry gelatin. The TAH can provide 3–8 Limin flow with a preload of 1–10 mm Hg against 100 mm Hg afterload. Anatomical fit of the pumping unit has been demonstrated in the pericardial space of 26 heart transplant recipients with average body weight of 78 kg. To date, 2 P-TAH and 4 EM-TAH (1 week) implantations were performed in 80–100 kg calves demonstrating excellent anatomical fit, controllability, and biocompatibility. This versatile TAH is suitable for a bridge to transplantation or permanent heart replacement.
The many faces of the contact pathway and their role in thrombosis

Understanding inherent differences between thrombosis and hemostasis in the vascular system are critical to developing safe and effective anticoagulants. To this end, constituents of the contact activated and intrinsic pathway of coagulation appear to be involved in pathological thrombus formation, but are not required for normal hemostasis. In addition to coagulation, activation of the contact system is involved in fibrinolytic, inflammatory, and angiogenic processes that can also contribute to the thrombotic environment. This review discusses the role of the contact system in these processes, and highlights the potential of FXII and FXI as safer targets for antithrombotic therapy.
Strain differences in pH-sensitive K+ channel-expressing cells in chemosensory and nonchemosensory brain stem nuclei

The ventilatory CO2 chemoreflex is inherently low in inbred Brown Norway (BN) rats compared with other strains, including inbred Dahl salt-sensitive (SS) rats. Since the brain stem expression of va...
Implications of recent asperity failures and aseismic creep for time-dependent earthquake hazard on the Hayward fault

Abstract The probability of large seismic events on a particular fault segment may vary due to external stress changes imparted by nearby deformation events, including other earthquakes and aseismic processes, such as fault creep and postseismic relaxation. The Hayward fault (HF), undergoing both seismic and aseismic fault slip, provides a unique opportunity to study the mutual relation of seismic and aseismic processes on a fault system. We use surface deformation data obtained from InSAR (interferometric synthetic aperture radar), creepmeters and alinement arrays, together with constraints provided by repeating earthquakes to investigate the kinematics of fault creep on the northern HF and its relation to two seismic clusters ( M w ≤ 4.1 ) in October 2011 and March 2012, and an M w 4.2 event in July 2007. Recurrences of nearby repeating earthquakes show that these episodes involved both seismic and aseismic slip. We model the stress changes due to fault creep and the recent seismic activity on the locked central asperity of the HF, which is believed to be the rupture zone of past and future M ~7 earthquakes. The results show that the shallow fault creep stresses the major locked central patch at an average rate of 0.001–0.003 MPa/yr, in addition to background stressing at 0.01–0.015 MPa/yr. Given the time-dependent nature of the creep, occasional deviations from this stressing rate occur. We find that the 2011 seismic cluster occurred in areas on the fault that are stressed up to 0.01 MPa/yr due to aseismic slip on the surrounding segments, suggesting that the occurrence of these events was encouraged by the fault creep. Changes in the probability of major earthquakes can be estimated from the imparted stress from the recent earthquakes and associated fault creep transients. We estimate that the 1-day probability of a large event on the HF only increased by up to 0.18% and 0.05% due to the static stress increase and stressing rate change by the 2011 and 2012 clusters. For the July 2007 south Oakland event ( M w 4.2) the estimated increase of short-term probabilities is 50%, highlighting the importance of short-term probability changes due to transient stress changes.
Purdue Ingestive Behavior Research Center symposium 2007: influences on eating and body weight over the lifespan--childhood and adolescence.

In the introductory presentation [1], Linda Adair reviewed the epidemiological data on childhood and adolescent obesity pointing out the increased overweight (17%) and increased at risk to become overweight (16%) over the last 5 years of NHANES data (1999–2004). Potentially very disturbing was a sharp increase in weight in the 2–5 year age group, which has been reflected anecdotally in the difficulty many parents have encountered fitting their toddlers into standard car seats. Differences in obesity prevalence associated with race/ethnicity and socioeconomic status were also discussed. For example, the highest overall overweight prevalence was observed in African and Mexican American youth. Further, Linda Adair described the susceptibility to developing obesity that occurs during specific stages of development, including the prenatal period, infancy, mid-childhood and adolescence, and considered some of the influential factors unique to each of these stages. For example, prenatal exposure to over- or undernutrition, rapid growth in early infancy, an early adiposity rebound in childhood, and early pubertal development have all been implicated in the development of obesity. She also considered the importance of studying weight trajectories, as deviations in weight that occur during one stage of development can influence or interact with factors operating at subsequent stages. Finally, some new or controversial factors contributing to development of obesity at various stages were reviewed, including the protective effect of breastfeeding and the role of a child’s temperament in influencing parents feeding strategies.
A quantitative study of the development of type II pneumocytes in fetal lung.

Cell populations dissociated from fetal rabbit lungs were analyzed by laser flow cytometry for the presence of type II pneumocytes. These cells are distinguishable by the staining of their lamellar bodies with the fluorescent lipophilic dye, phosphine-3R and by their intensity of low-angle light scatter. Lung cells were obtained by enzymatic dissociation from fetal rabbits at gestational ages of 24 d, 27 d, and from 2-d newborn rabbits. Flow cytometric analysis was sufficiently sensitive to discriminate between fetuses. Quantitative analysis of type II pneumocytes showed that newborn rabbits had a distinct cell subpopulation in a region of low-angle light scatter and phosphine-3R fluorescence intensity similar to that previously reported on type II cells from adult rabbits. By contrast, 24-d gestation rabbits had a negligible type II cell subpopulation. Fetuses of 27 and 30 d gestation showed a slow but progressive increase in the numbers of cells in the type II region. Mathematical analyses of light scatter and fluorescence intensity distributions were used to define statistically significant (P less than .05) boundaries that characterize the development of the type II cell subpopulation in fetal rabbit lung. The methods employed offer new possibilities for quantification of developing lung cell subpopulations of particular interest to the problem of respiratory distress syndrome in human neonates.
Assessment of multislice CT to quantify pulmonary emphysema function and physiology in a rat model

Purpose: The purpose of this study is to evaluate multi-slice computed tomography technology to quantify functional and physiologic changes in rats with pulmonary emphysema. Method: Seven rats were scanned using a 16-slice CT (Philips MX8000 IDT) before and after artificial inducement of emphysema. Functional parameters i.e. lung volumes were measured by non-contrast spiral scan during forced breath-hold at inspiration and expiration followed by image segmentation based on attenuation threshold. Dynamic CT imaging was performed immediately following the contrast injection to estimate physiology changes. Pulmonary perfusion, fractional blood volume, and mean transit times (MTTs) were estimated by fitting the time-density curves of contrast material using a compartmental model. Results: The preliminary results indicated that the lung volumes of emphysema rats increased by 3.52±1.70mL (p<0.002) at expiration and 4.77±3.34mL (p<0.03) at inspiration. The mean lung densities of emphysema rats decreased by 91.76±68.11HU (p<0.01) at expiration and low attenuation areas increased by 5.21±3.88% (p<0.04) at inspiration compared with normal rats. The perfusion for normal and emphysema rats were 0.25±0.04ml/s/ml and 0.32±0.09ml/s/ml respectively. The fractional blood volumes for normal and emphysema rats were 0.21±0.04 and 0.15±0.02. There was a trend toward faster MTTs for emphysema rats (0.42±0.08s) than normal rats (0.89±0.19s) with p<0.006, suggesting that blood flow crossing the capillaries increases as the capillary volume decreases and which may cause the red blood cells to leave the capillaries incompletely saturated with oxygen if the MTTs become too short. Conclusion: Quantitative measurement using CT of structural and functional changes in pulmonary emphysema appears promising for small animals.
Single-copy vectors for integration at the SaPI1 attachment site for Staphylococcus aureus

We have previously reported the construction of Staphylococcus aureus integration vectors based on the staphylococcal pathogenicity island 1 (SaPI1) site-specific recombination system. These are shuttle vectors that can be propagated in Escherichia coli, which allows for standard DNA manipulations. In S. aureus, these vectors are temperature-sensitive and can only be maintained at non-permissive (42 °C) temperatures by integrating into the chromosome. However, most S. aureus strains are sensitive to prolonged incubations at higher temperatures and will rapidly accumulate mutations, making the use of temperature-sensitive integration vectors impractical for single-copy applications. Here we describe improved versions of these vectors, which are maintained only in single-copy at the SaPI1 attachment site. In addition, we introduce several additional cassettes containing resistance markers, expanding the versatility of integrant selection, especially in strains that are resistant to multiple antibiotics.
Time-Resolved Structural Characterization of Formation and Break-up of Rhodium Clusters Supported in Highly Dealuminated Y Zeolite

Mononuclear rhodium complexes incorporating two ethylene ligands and anchored to dealuminated zeolite Y by two Rh-O bonds were characterized by transient extended X-ray absorption fine structure (EXAFS) spectroscopy and infrared (IR) spectroscopy as they were converted in the presence of H{sub 2}. EXAFS spectra indicate reduction of the rhodium in the complex at 298 K to form rhodium clusters less than 3 {angstrom} in average diameter. Contacting of the resultant clusters with C{sub 2}H{sub 4} led to their oxidative fragmentation, and the process was reversible. When the H{sub 2} treatment was carried out at a higher temperature (373 K), larger clusters formed. The reduction and oxidation of the rhodium were confirmed by X-ray absorption near edge spectra. During the ethylene treatments, ethyl groups formed on the rhodium, as indicated by IR spectra; treatment in H{sub 2} led to hydrogenation of these groups to form ethane, and the ethyl groups are inferred to be intermediates in the catalytic hydrogenation of ethylene. Ethylene in the gas phase helps to stabilize rhodium in the form of mononuclear complexes on the zeolite during catalysis, hindering the cluster formation.
Computer simulation of reversible martensitic transformations

This article reports the results of computer simulation studies of reversible, athermal martensitic transformations in idealized, two-dimensional crystals. The transformation is accomplished by se-quentially transforming elementary cells. The model accounts for the elastic strain developed during the transformation, assuming homogeneous elastic constants, negligible interfacial tension, and no external stress. The effects of frictional resistance to the transformation and plastic relaxation of the elastic strain are included in a simple way. The model is used to study the sources of hysteresis in the temperature-transformation (TT) curve and in the microstructural transformation path when the transformation is reversed. The central result is that some hysteresis is inevitable in a transformation of the type studied here. Even in the absence of friction and plastic relaxation, the transformation follows a path in which sequential elements of martensite relax the elastic strain of those that have previously formed. This causes the martensite to form in bursts and has the consequence that the reverse transformation does not reverse the path of the forward transformation. Friction and plastic relaxation increase hysteresis.
Glutamate-cysteine ligase attenuates TNF-induced mitochondrial injury and apoptosis

Abstract Glutathione (GSH) is important in free radical scavenging, maintaining cellular redox status, and regulating cell survival in response to a wide variety of toxicants. The rate-limiting enzyme in GSH synthesis is glutamate-cysteine ligase (GCL), which is composed of catalytic (GCLC) and modifier (GCLM) subunits. To determine whether increased GSH biosynthetic capacity enhances cellular resistance to tumor necrosis factor-α– (TNF-α–) induced apoptotic cell death, we have established several mouse liver hepatoma (Hepa-1) cell lines overexpressing GCLC and/or GCLM. Cells overexpressing GCLC alone exhibit modest increases in GCL activity, while cells overexpressing both subunits have large increases in GCL activity. Importantly, cells overexpressing both GCL subunits exhibit increased resistance to TNF-induced apoptosis as judged by a loss of redox potential; mitochondrial membrane potential; translocation of cytochrome c to the cytoplasm; and activation of caspase-3, caspase-8, and caspase-9. Analysis of the effects of TNF on these parameters indicates that maintaining mitochondrial integrity mediates this protective effect in GCL-overexpressing cells.
Understanding Conditional Probability

Summary This article offers a new approach to teaching the difficult concept of conditional probability.
Tumor Necrosis Factor-α Induces mRNA for Collagenase and Timp in Human Skin Fibroblasts

We demonstrated previously that growth promoting factors in general could induce the secretion of interstitial collagenase into the medium of human fibroblast cells (HF). In this study, the effect of tumor necrosis factor-ct (TNF-α) on the induction of collagenase and tissue inhibitor of metalloproteinases (TIMP) was examined. Stimulation of quiescent HF cells with 10 ng/ml TNF-α induced the secretion of Mr 57,000, 52,000 procollagenases into the medium. The collagenase activity was elevated 2.8-fold after TNF-α treatment. Northern blot analysis of the steady-state mRNA indicated a tenfold elevation of collagenase transcript after 24 h treatment with 10 ng/ml TNF-α. The increase in collagenase mRNA was due to transcriptional activation of collagenase gene activity. TIMP mRNA level increased three-fold after TNF-α treatment. The activity of TNF-α on collagenase and TIMP induction may play an important role in tissue inflammatory, repair and remodeling processes after wound and injury.
A New Principle for Measuring Electrical Length and Deviation from Linear Phase

This paper presents a unique way to measure the equivalent electrical length of a network as well as its deviation from linear phase. The measurement technique used is based upon a variable length transmission line simulator, built into the IF-structure of a 1.3 GHz Network Analyzer, but can be applied to higher frequencies. The new method allows to insert much more electrical length than the mechanical line stretchers do, without disturbing the measurement with additional mismatch errors. In addition to a calibrated readout of the equivalent electrical length in meters, the deviations from linear phase of a network can be presented very accurately in a real time swept display.
Exploring environmental awareness in the electronics manufacturing industry: a source for innovation

Environmental awareness gained a very high attention in the last couple of decades. Most of these diverse environmental concerns, were addressed in several unique waves across independent industries. This paper describes how the increase in concern for the environment during the past several decades has impacted technology management in the electronics industry and demonstrate the use of a model for comparing the strategic benefits of environmental management systems across companies. The generic competitive environmental strategies diagram described four different business strategies that guided a selection of company analyses resulting in categories of environmental business strategies with competitive advantage. Thus with proper implementation, there is an opportunity to being green, even in the high tech electronics industry. Finally the paper finishes with a set of propositions for exploring the linkages between these strategies and potential innovations.
What's the 'hood got to do with it? Parental perceptions about how neighborhood mechanisms affect their children

ABSTRACT:During the past decade, a rapidly expanding body of empirical research has emerged that statistically links disadvantaged neighborhood environments with social and economic outcomes of low-income, minority children. Nonetheless, the mechanisms by which neighborhoods putatively affect children remain poorly understood. This article examines the perceptions of low-income parents regarding how their neighborhood might affect their children. We examine quantitative and qualitative data gathered from phone interviews with 246 parents who live in subsidized housing scattered across a wide variety of neighborhoods in Denver, Colorado. We supplement this information with data obtained through a series of focus group interviews with a subset of these parents. Our findings indicate that low-income parents perceive the following primary neighborhood mechanisms: (1) the degree (or lack) of social norms and collective efficacy (24%); (2) influence of children’s peers (12%); (3) exposure to crime and violence ...
Service design of consumer data intermediary for competitive individual targeting

Individual targeting, a marketing strategy that firms target individual consumers with tailored offers, is currently a widespread practice. Customer data intermediaries (CDIs) have emerged recently to help firms learn their prospective customers and launch their target marketing campaigns. This paper uses a common-value auction framework to study how a CDI designs and differentiates its information services to help two competing firms identify and target valuable customers. We characterize the firms' equilibrium target marketing strategies. The results show that the CDI serves one firm exclusively in unpromising markets where the proportion of valuable customers is relatively low, and provides both firms with differentiated services in promising markets where the proportion of valuable customers is relatively high. In addition, the CDI differentiates its services less when the proportion of valuable customers is higher.
Integration of mutual information and text mining methods for extracting gene-gene interactions from gene expression data

Mutual information algorithms have been used for the identification of gene-gene interactions in gene expression data. These methods have been hindered by a high false-positive rate. We explored the use of free-text abstracts as an additional source of information for assessing the biological relevance of predicted gene interactions. Our results suggest that the performance of a mutual information algorithm on this task can be enhanced by using text mining methods to refine the initial set of predictions.
Aerosol regurgitation as a laryngeal-sensitizing event explaining acute laryngospasm.

Acute laryngospasm is an incapacitating event with obscure etiology. Two cases of documented gastric aerosol regurgitation and laryngeal exposure to aerosol acid with subsequent acute laryngospasm are presented. A third individual with laryngospasm was noted to reflux gas. One individual was aware of the regurgitation etiology of the laryngospasm; the second two were not. Videofluoroscopic recording of the acute event in the second patient documented the nature of two episodes occurring within the fluoroscopy suite.
Usage statistics for MTS

The following report is presented in response to Professor Browne's request for case studies of performance measurement projects; this study takes a macroscopic view of a large-scale time sharing and batch processing installation.
Sequential sampling plans for estimating European corn borer (Lepidoptera: Crambidae) and corn earworm (Lepidoptera: Noctuidae) larval density in sweet corn ears

Abstract We developed a flexible fixed-precision sequential sampling plan for estimating the density of European corn borer, Ostrinia nubilalis Hubner and corn earworm, Helicoverpa zea (Boddie), larvae, using infestation data collected from 1994 to 2000. The purpose of each sampling plan was to provide statistically sound estimates of larval densities for each pest in sweet corn ears, near harvest, with minimal cost. Sweet corn variety plots and commercial production fields were sampled to obtain a wide range of O. nubilalis and H. zea densities typically found in sweet corn, in the Midwestern USA. Sampling parameters were estimated from 84 and 68 data sets for O. nubilalis and H. zea , respectively. An additional 15 independent data sets, for each species, were used to validate the fixed-precision sequential sampling plans with resampling software. Dispersion patterns for O. nubilalis and H. zea were determined to be random and uniform, respectively, from Taylor's power law. For O. nubilalis , at densities of 0.24–4.08 larvae/ear, an average sample number (ASN) of only 38 ears was necessary to achieve a desired precision level (SE/mean) of 0.25. As the precision level was increased to 0.10, average sample size increased to 227 ears. For H. zea , at densities of 0.20–2.05 larvae/ear, an ASN of 27 ears was required to achieve a desired precision level of 0.25. As the precision level was increased to 0.10, sample size increased to 160 ears. The sequential sampling plans will be useful to researchers for quantitative assessment of integrated pest management (IPM) strategies, via rapid estimation of larval density per ear, the primary determinant of IPM efficacy and product quality near harvest. Additionally, these plans can be used to determine the background density necessary for estimating the frequency of O. nubilalis or H. zea larvae found in transgenic Bt sweet corn ears expressing Bacillus thuringiensis proteins.
Fiber-Coupled Radiation Dosimeter

Fiberoptic-based, radiation measurement methods provide a convenient approach for remotely monitoring hazardous or difficult-to-access areas such as nuclear waste sites or sampling wells for in situ ground water monitoring.
Stealth marketing as a strategy

Abstract Stealth marketing has gained increasing attention as a strategy during the past few years. We begin by providing a brief historical review to provide some perspective on how this strategy has been practiced in a myriad of ways in various parts of the world, and how it has consequently evolved in the emerging new marketplace. A more inclusive definition of stealth marketing is then proposed to conceptually understand its use in various contexts. Specifically, we propose a new typology of stealth marketing strategies based on whether businesses or competitors are aware of them, and whether they are visible to the targeted customers. We further provide suggestions of how firms can counter the stealth marketing strategies used by their competitors. Contrary to conventional wisdom, evidence is also provided about how such strategies can be used for “doing good” for society. Finally, the assessment of efficiency and effectiveness of stealth marketing strategies, and their related ethical implications, are discussed.
Formation of Smooth, Conformal Molecular Layers on ZnO Surfaces via Photochemical Grafting

We have investigated the photochemical grafting of organic alkenes to atomically flat ZnO(1010) single crystals and ZnO nanorods as a way to produce functional molecule–semiconductor interfaces. Atomic force microscopy shows that photochemical grafting produces highly conformal, smooth molecular layers with no detectable changes in the underlying structure of the ZnO terraces or steps. X-ray photoelectron spectroscopy measurements show that grafting of a methyl ester-terminated alkene terminates near one monolayer, while alkenes bearing a trifluoroacetamide-protected amine form very smooth multilayers. Even with multilayers, it is possible to deprotect the amines and to link a second molecule to the surface with excellent efficiency and without significant loss of molecules from the surface. This demonstrates that the use of photochemical grafting, even in the case of multilayer formation, enables multistep chemical processes to be conducted on the ZnO surface. Photoresponse measurements demonstrate that...
Lowering obstacles to HIV prevention services: Effects of a brief, telephone-based intervention using motivational enhancement therapy

Background: Brief and low-burden HIV risk reduction counseling interventions are needed for populations at greatest risk for HIV infection.Purpose: This randomized controlled trial tested a brief theory-based counseling intervention delivered entirely over the telephone for men who engage in unprotected intercourse with men.Methods: Participants received either risk reduction counseling that included information, motivational enhancement and behavior skills building, or brief HIV education counseling. A total of 319 participants completed follow-up assessments over a 10-month period. Descriptive and random effects mixed models are used to evaluate findings.Results: Results demonstrate that a brief telephone intervention can reach and engage high-risk men in risk reduction counseling. Nearly one third of participants identified as men of color; the median age was 33 years. Participants in both counseling conditions increased their motivation and behavioral skills to practice safer sex and reduced their number of sex partners and frequencies of engaging in unprotected anal sex over the study observation period. However, there were few differences between intervention conditions.Conclusions: The effects of repeated measurement reactivity and brief interpersonal consciousness raising may account for the lack of differences between counseling conditions and the decrease in risk for all participants over time.
Large electromechanical response in ZnO and its microscopic origin

The electromechanical coefficient ${d}_{33}$ of wurtzite ZnO is determined by direct first-principles density functional calculations which are performed for solids under finite electric fields. Our theoretical ${d}_{33}$ value of $12.84\phantom{\rule{0.3em}{0ex}}\mathrm{pC}∕\mathrm{N}$ turns out to be in good agreement with experiment. This electromechanical response in ZnO (which is the largest among the known tetrahedral semiconductors) is found to originate from the strong coupling between strain and polarization, namely, a notably large $\ensuremath{\beta}$ parameter. We further show that the electromechanical response in wurtzite semiconductors bears a previously unknown resemblance to the polarization rotation mechanism in ferroelectric $\mathrm{Pb}(\mathrm{Zn}\mathrm{Nb}){\mathrm{O}}_{3}\ensuremath{-}\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ and $\mathrm{Pb}(\mathrm{Mg}\mathrm{Nb}){\mathrm{O}}_{3}\ensuremath{-}\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ single-crystal solid solutions. Our results demonstrate that, different from what is commonly believed, the main effect of electric fields in wurtzite semiconductors is not to elongate the polar chemical bonds, but to rotate those bonds that are non-collinear with the polar axis. This finding also suggests that the electromechanical response in wurtzite materials is governed mainly by the ease of bond bending, which may provide an useful scheme for designing better piezoelectric semiconductors with enhanced performance.
Measurement of free amino acid levels in ultrafiltrates of blood plasma by high-performance liquid chromatography with automatic pre-column derivatization.

Abstract Although there are many techniques available for the analysis of amino acids, deproteinization is still one of the major problems in the analysis of amino acids in physiological fluids. The method used to prepare the plasma and to remove the plasma protein has a marked effect on the final results. The most widely used method of deproteinization is precipitation with 5-sulphosalicylic acid followed by centrifugation to remove the precipitated protein. We have not had success in using this deproteinization agent for the analysis of plasma amino acids by a high-performance liquid chromatographic method with automatic pre-column o -phthaldialdehyde—3-mercaptopropionic acid and 9-fluorenylmethyl chloroformate derivatization because of the adverse effect of the sulphosalicyclic acid supernatant on the quantitation and separation. Ultrafiltration was used as an alternative method for the preparation of plasma samples in this experiment. The results were satisfactory for the analysis of plasma amino acids in 1500 samples during a period of four years. Some factors that might influence the results of the ultrafiltration were investigated.
Fuel relocation in Molten Salt Reactors in a loss of fuel solubility event

Abstract This study considers the consequences of precipitation events in Molten Salt Reactors (MSR). Such events come about as a result of loss of fuel solubility within coolant (FLiBe). It is proposed that the ensuing growth and agglomeration of precipitates may result in relocation (radial stratification) of the fuel along the centerline channel. We assume that in such precipitation events, the fuel solid is not uniformly distributed. This assumption is valid at relatively low Reynolds numbers, where the turbulent stresses are much smaller than the buoyancy forces, a situation which is likely in an MSR. The neutronic impact of such a relocation is analyzed.
Risk Factors for Surgical Site Infections Following Spinal Fusion Surgery at a Children's Hospital

BACKGROUND/OBJECTIVES: Postoperative infections especially surgical site infections (SSIs) are serious complications of spine fusions requiring extensive medical care and frequently additional surgical intervention. Between 1996 and 1999 at a children's hospital, a significant increase in the SSI rate was identified in patients with no known risk factors for infection preoperatively. The objectives of the study were to identify specific risk factors for SSIs in patients undergoing spinal fusion surgery and to analysis the characteristics of these infections. METHODS: A retrospective cohort study with medical chart review of all patients (ages 6 months to 21 years of age) who underwent spine fusion surgery between Jan. 1999 and Dec. 2003. Risk factors for SSI were determined using univariate analysis and multivariate logistic regression. SSIs were analyzed using CDC and NNSI guidelines. RESULTS: During the 5-year study, 234 spine fusion surgeries were performed with 19 (8%) patients developing a SSI. Univariate analysis identified diagnosis (idiopathic, neuromuscular, or structural scolotic curves), a secondary condition (such as cerebral palsy, myelodysplasia, an autoimmune condition, or genetic syndromes), and ASA score were significant preoperative risks with cut time, blood loss, blood replacement (type and amount), and bone graft used significant procedural risks. Postoperatively, hospital length of stay, antibiotic use, transfer to the ICU, and other non-infectious postoperative problems were significant. In the multivariate logistic regression, only cut time remained significant. Of the 19 SSIs, 11 (58%) occurred ≤ 30 days; 3 (16% occurred between 31 to 365 days, and 5 (26%) were identified more than 366 days postoperatively. Sixty three percent were classified as organ/space infections, requiring extensive medical intervention. Comparison of National Nosocomial Infection Surveillance risk index and study population infection rates Number of Risk Factor NNIS Rate Study Population Rate 0 1.2% 1.3% 1 3.1% 5.1% 2,3 7.2% 1.7% CONCLUSIONS: Diagnosis, cut time and ASA were found to be significant in this study. The identification of SSIs after 366 days (2 to 5 years) postoperatively is becoming an increasing concern requiring surveillance for infection to continue for several years to determine the actual SSI rate for this population of patients.
Presentation and symptom predictors of coronary heart disease in patients with and without diabetes.

The aims of this prospective, observational study were to compare: (1) symptom presentation of coronary heart disease (CHD) between patients with and without diabetes and (2) symptom predictors of CHD in patients with and without diabetes. We directly observed 528 patients with symptoms suggestive of CHD as they presented to the ED of a 900-bed cardiac referral center in the northeastern United States. There were no significant differences in symptom presentation of CHD between patients with and without diabetes, although patients with diabetes were slightly more likely to present with shortness of breath (P = .056). Patients with diabetes reported their symptoms to be more severe compared with those without diabetes (P = .036). Neck/throat pain and arm/shoulder pain were of borderline significance in predicting CHD in patients with diabetes (P = .059 and P = .052, respectively). Classic chest symptoms and diaphoresis were independent predictors of CHD in patients without diabetes (P = .002 and P = .049, respectively). The perceived severity of symptoms was not predictive of CHD in patients with or without diabetes. Symptoms thought to be diagnostic of CHD are not helpful in patients with diabetes. Future research should focus on identifying more useful predictors of CHD in patients with diabetes.
Two-photon absorption imaging and self-phase modulation imaging with shaped laser pulses

We present a new method for deep tissue imaging using nonlinear optics. Specific tailored laser pulses permit measurement of two-photon absorption or self-phase modulation with modest near-IR powers (1-10mW), giving good penetration and molecular specificity.
Leveraging diversity through faculty perception of their power to influence diversity

This study measured faculty perception of their power to influence the diversity initiative goals. Nine hundred faculty members were sent the questionnaire; 20% responded to the survey with 17% agreeing to the informed consent and completing the questionnaire. Findings indicate that faculty are undecided of whether or not they have the power to influence the diversity initiative suggesting that the hypothesis that faculty are not engaged in promotion of the university's diversity initiative is true.
Inversion of the Bloch equations with T 2 relaxation: An application of the dressing method

The Bloch equations, with time-varying driving field, and ${T}_{2}$ relaxation, are expressed as a scattering problem, with ${\ensuremath{\Gamma}}_{2}{=1/T}_{2}$ as the scattering parameter, or eigenvalue. When the rf pulse, describing the driving field, is real, this system is equivalent to the $2\ifmmode\times\else\texttimes\fi{}2$ Zakharov-Shabat eigenvalue problem. In general, for complex rf pulses, the system is a third-order scattering problem. These systems can be inverted, to provide the rf pulse needed to obtain a given magnetization response as a function of ${\ensuremath{\Gamma}}_{2}$. In particular, the class of ``soliton pulses'' are described, which have utility as ${T}_{2}$-selective pulses. For the third-order case, the dressing method is used to calculate these pulses. Constraints on the dressing data used in this method are derived, as a consequence of the structure of the Bloch equations. Nonlinear superposition formulas are obtained, which enable soliton pulses to be calculated efficiently. Examples of one-soliton and three-soliton pulses are given. A closed-form expression for the effect of ${T}_{1}$ relaxation for the one-soliton pulse is obtained. The pulses are tested numerically and experimentally, and found to work as predicted.
Nanomechanical characterization of SAC305 solder joints - effects of aging

In this work, aging phenomena in solder joints have been explored by nano-mechanical testing. Using nanoindentation techniques, the elastic, plastic, and creep behavior of SAC305 solder joint materials have been explored for various aging conditions. Single crystal solder joints were first extracted from PBGA assemblies (14 × 14 mm, 0.8 mm ball pitch, 0.46 mm ball diameter), and then subjected to aging at T = 125 C for various aging times. After the aging exposures, the joints were loaded in the nano-indentor, and the load-deformation behavior during indentation was used to characterize the mechanical properties of the solder joints for various aging conditions including modulus, hardness, and yield stress. Using constant force at max indentation, the creep response of the aged and non-aged solder joint materials have also been measured for various stress levels. With this approach, aging effects have been quantified in joints, and their magnitudes correlated to those observed in testing of miniature bulk specimens. The measured results have demonstrated that the mechanical behavior of actual solder joints degrade significantly with aging. The results show that the aging induced degradations of the mechanical properties (modulus, hardness) in the SAC joints were of similar order (30-40%) as those seen previously in the testing of larger “bulk” uniaxial solder specimens. The creep rate of the tested SAC305 joints were found to increase by up to 75X with one year of aging. These degradations, while significant, were much less than those observed in larger bulk solder uniaxial tensile specimens with several hundred grains, where the increase was over 900X. Additional testing has been performed on very small tensile specimens with approximately 10 grains, and the aging-induced creep rate degradations found in these specimens were on the same order of magnitude as those observed in the single grain joints. Thus, the lack of the grain boundary sliding creep mechanism in the single grain joints is an important factor in avoiding the extremely large creep rate degradations ocurring in larger bulk SAC samples. The test results also show that the elastic, plastic, and creep properties of the solder joints and their sensitivities to aging are highly dependent on their crystal orientations. Polarized light microscopy and Electron Back Scattered Diffraction (EBSD) were used to identify the grain structure and crystal orientations in the tested joints. Microstructural analysis of the joints has shown that Ag3Sn precipitates coarsen during isothermal aging, which results in fewer but larger particles. The Sn dendrite cell size also was observed to grow significantly, but the boundaries are no longer well defined due to coarsening.
Harmonic Disturbance Rejection in Tracking Control of Euler-Lagrange Systems: An External Model Approach

We consider the systematic design of tracking controllers for Euler-Lagrange systems which are affected by unmeasurable harmonic disturbances. The problem addressed in this paper departs from the classic setup of the regulator problem and its solution is based on the internal model principle in two aspects. First, the presence of an exogenous disturbance affecting the measurements of the plant output is taken into account. Second, we aim at designing a nominal tracking controller using standard techniques, independently of the device that is used to provide asymptotic rejection of the disturbance. The latter is then added to the stable loop, in such a way that asymptotic cancellation of the disturbance is guaranteed under mild conditions. The device in question is referred to as an external model of the exogenous system, to emphasize the departure from the classic internal model-based design. The external model is endowed with an adaptation mechanism that allows it to deal with uncertainties on the frequencies of the exogenous signals as well. To validate our approach, we provide experimental results for a two-degrees-of-freedom (2-DOF) helicopter model
Stripping interfering sugars from samples using adapted bacteria.

Abstract Bacteria adapted to individual sugars quickly remove targeted sugars — stripping them — from samples in which unwanted sugars interfere. Adapted bacteria are equivalent to specific reagents for removal of sugars down to bacterial K m values, micromolar to submicromolar concentrations. Bacterial stripping is a simple method, useful when background sugars in micro-to millimolar concentrations (or larger) interfere with analysis of sought-for sugars. Bacteria such as Escherichia coli and Klebsiella are easily adapted to individual sugars such as lactose, fructose, etc., by growing the bacteria on them. Hence one can easily create (and store) many kinds of cells ready to sponge up or strip out unwanted compounds. E. coli specifically remove several sugars from samples containing 100–500 nmol of sugars, using 1–5 mg of adapted cells, and 25°C temperatures. Stripping requires 1–5 min and consists of mixing cells and sample, spinning down the cells, and withdrawal of stripped supernate. A 1–5 min interval is adequate for uptake and stripping, but far too short for cells to metabolize the sugars that were taken up. Hence the cells do not leak metabolites, but act as specific adsorbants without injection of appreciable byproducts into the sample.
Fatigue crack growth in a polycrystalline Ni3Al+B alloy

Several accounts of the influence of boron on tensile ductility of polycrystalline Ni/sub 3/Al have been published. There is, as yet, no generally accepted mechanism for the boron ductilizing effect. Nevertheless, the ability to produce ductile Ni/sub 3/Al permits determination of other mechanical properties over a range of temperatures. With the exception of a brief report of cyclic life and crack growth behavior of Ni/sub 3/Al+B there are no published data on the resistance of boron-doped Ni/sub 3/Al to cyclic loading. In this paper the results of crack growth experiments on polycrystalline Ni/sub 3/Al prepared by ingot metallurgy are reported. Tests have been carried out at 25/sup 0/C in air and in vacuum at 500/sup 0/C and 600/sup 0/C. Crack growth thresholds are higher than in conventional alloys, perhaps because of difficulty in nucleating dislocation pairs at a crack tip. Crack growth rates increase with temperature between 25/sup 0/C and 600/sup 0/C in spite of a rising yield stress and decreasing notch sensitivity over the same temperature range. Environmental effects due to absorbed oxygen appear to be the most likely factor influencing crack growth rates at elevated temperatures.