cssi/SciSciGPT-SciSciNet huggingface dataset:
On blade/casing rub problems in turbomachinery: An efficient delayed differential equation approach

Abstract This paper presents an alternative pathway in studying the ubiquitous blade/casing rub problem in turbomachinery. Bladed disks interfere with the stationary shroud (casing) for a variety of reasons, such as axial offsets, thermal expansions. Both components being compliant, time-varying interface characteristics, nonlinearities and uncertainties in the rub forces make this dynamics very complex to model and analyze. The main idea in this paper originates from the conjecture that this dynamics is inherently akin to internal machining operation which also deals with compliant cutters (blades) but relatively more rigid workpiece (casing). This analogy directs our attention to the fact that the blade/casing impingement dynamics manifests a ‘regenerative mechanism’ which is impregnated with time delays. The ensuing time-delayed system (TDS) can be stable, which is ideal. If it is unstable, however, the interference amplitudes between the blade and the casing grow, and the nonlinear effects become dominant. If the components survived the exercise, this evolution would reach a limit-cycle behavior. Existing literature indicates that this limit cycle mode is the common state of operation in most modern-day turbomachinery. Consequently, the state-of-the-art research effort is focused on minimizing its amplitude to alleviate the destructive levels of fatigue effect. In this article we consider a different perspective in looking at these problems, by proposing the conditions to achieve stable rub interference. For this, a recent mathematical tool of the authors’ group called the Cluster Treatment of Characteristic Roots (CTCR) is deployed. CTCR declares the complete stability outlook of such time-delayed systems in the space of the operational and design parameters. We show how this new capability can assist the design process of the blade-casing interface. Simulations, relevant stability observations and comparisons with a peer technique are provided for some case studies to demonstrate the capabilities of the approach.
Further toxicologic studies with commercial and candidate flame retardant chemicals. Part II

A number of commercial and candidate flame retardants were studied with regard to their toxicity to goldfish, inhibition of cholinesterase, inhibition of acetyl choline binding to its receptor and insecticidal properties. Several of the flame retardants were notably toxic to fish. Some of the compounds showed modest inhibition of cholinesterase and/or microsomal oxidases, but none inhibited acetyl choline receptor binding. Whereas several of the flame retardants showed little or no insecticidal properties when added alone to a housefly diet, piperonyl butoxide greatly synergised their toxicity to houseflies.
Temporal Patterns of Crashes of 16-to 17-Year-Old Drivers in Fairfax County, Virginia

Objective. To develop a better understanding of the frequency and characteristics of teenage driver crashes occurring during school commute times. Method. Data were obtained from police reports of crashes involving drivers ages 16–17 that occurred between September 2001 and August 2004 in Fairfax County, Virginia. Temporal patterns and other characteristics of crash involvement during the school year were examined, and crashes during school commute times were compared with those at other times. Results. Teenage driver crash involvement spiked during weekday school commute times. Compared with other times, crashes during school commute times were significantly more likely to involve multiple vehicles but less likely to result in injuries or involve drivers who were male, made driving errors, or had been drinking alcohol. Crashes during school commute times were more likely to involve more than one teenage driver and occur close to schools. Conclusions. Crashes involving teenage drivers are prevalent during...
Regulation of Abro1/KIAA0157 during myocardial infarction and cell death reveals a novel cardioprotective mechanism for Lys63-specific deubiquitination

Abro1 (also known as KIAA0157) is a scaffold protein that recruits polypeptides to assemble the BRISC (BRCC36-containing isopeptidase complex) deubiquitinating (DUB) enzyme. The four subunits of BRISC enzyme include Abro1, NBA1, BRE, and BRCC36 proteins. The DUB activity of the BRISC enzyme is exclusively directed against Lys63-linked polyubiquitin that does not have a proteolytic role but regulates protein function. In this report, we identified Abro1 as a specific interactor of THAP5, a zinc finger transcription factor that is involved in G2/M control and apoptosis. Abro1 was predominantly expressed in the heart and its protein level was regulated following experimentally induced myocardial ischemia/reperfusion (MI/R) injury. Furthermore, in patients with coronary artery disease (CAD), there was a dramatic increase in Abro1 protein level in the myocardial infarction (MI) area. Increase in Abro1 leads to a significant reduction in Lys63-linked ubiquitination of specific protein targets. Reducing the Abro1 protein level exacerbated cellular damage and cell death of cardiomyocytes due to MI/R injury. Additionally, overexpression of Abro1 in a heterologous system provided significant protection against oxidative stress-induced apoptosis. In conclusion, our results demonstrate that Abro1 protein level substantially increases in myocardial injury and coronary artery disease and this up-regulation is part of a novel cardioprotective mechanism. In addition, our data suggest a potential new link between Lys63-specific ubiquitination, its modulation by the BRISC DUB enzyme, and the development and progression of heart disease.
Interactions between benzene, toluene, and p-xylene (BTX) during their biodegradation.

A microbial consortium and Pseudomonas strain (PPO1) were used in studying biodegradation of benzene, toluene, and p-xylene under aeorbic conditions. Studies involved removal of each compound individually as well as in mixture with the others. Both cultures exhibited a qualitatively similar behavior toward each compound. Both the pure culture and the consortium grew on benzene following Monod kinetics, on toluene following inhibitory (Andrews) kinetics, whereas neither could grow on P-xylene. Benzene and toluene mixtures were removed under cross-inhibitory (competitive inhibition) kinetics. In the presence of benzene and/or toluene, p-xylene was cometabolically utilized by both cultures, but was not completely mineralized. Metabolic intermediates of p-xylene accumulated in the medium and were identified. Benzene and toluene were completely mineralized. Cometabolic removal of p-xylene reduced the yields on both benzene and toluene. Except for cometabolism, kinetic constants were determined from data analysis and are compared with values published recently by other researchers. © 1994 John Wiley & Sons, Inc.
Photonic crystal circuits

A theory is presented for the flow of electromagnetic energy in photonic crystal circuits. Photonic crystal circuits are waveguide networks in photonic crystals. The theory is based on a set of difference equations which describe the propagation of electromagnetic waves in particular types of photonic crystal waveguides. Solutions are given for the transmission and reflection of electromagnetic waves from barriers in an otherwise infinitely long straight photonic crystal waveguide, from a junction of an infinite and a semi-infinite photonic crystal waveguide, and from an optical switching circuit. The theory developed is applicable to extended circuits with complex topologies. It is applicable to circuits in two-dimensional and three-dimensional photonic crystals.
Evolution of Electron States with Composition in GaAsN Alloys

We present a theory of the evolution of the electronic structure of GaAsN alloys, from the dilute impurity limit to the fully formed alloy. Using large scale empirical pseudopotential calculations, we show how substitutional nitrogen forms Perturbed Host States (PHS) inside the conduction band whereas small nitrogen aggregates form localized Cluster States (CS) in the band gap. By following the evolution of these states with increasing nitrogen composition we develop a model that explains many of the experimentally observed phenomena, including high effective masses, Stokes shift in emission versus absorption, and anomalous pressure dependence.
Cooperative data dissemination to mission sites

Timely dissemination of information to mobile users is vital in many applications. In a critical situation, no network infrastructure may be available for use in dissemination, over and above the on-board storage capability of the mobile users themselves. We consider the following specialized content distribution application: a group of users equipped with wireless devices build an ad hoc network in order cooperatively to retrieve information from certain regions (the mission sites). Each user requires access to some set of information items originating from sources lying within a region. Each user desires low-latency access to its desired data items, upon request (i.e., when pulled). In order to minimize average response time, we allow users to pull data either directly from sources or, when possible, from other nearby users who have already pulled, and continue to carry, the desired data items. That is, we allow for data to be pushed to one user and then pulled by one or more additional users. The total latency experienced by a user vis-vis a certain data item is then in general a combination of the push delay and the pull delay. We assume each delay time is a function of the hop distance between the pair of points in question. Our goal in this paper is to assign data to mobile users, in order to minimize the total cost and the average latency experienced by all the users. In a static setting, we solve this problem in two different schemes, one of which is easy to solve but wasteful, one of which relates to NP-hard problems but is less so. Then in a dynamic setting, we adapt the algorithm for the static setting and develop a new algorithm with respect to users' gradual arrival. In the end we show a trade-off can be made between minimizing the cost and latency.
Thumbtack Bioassay: A Quick Method for Measuring Plant Resistance to Twospotted Spider Mites (Acari: Tetranychidae)

A novel bioassay for measuring plant resistance to twospotted spider mites, Tetranychus urticae Koch, is described. The performance of the bioassay is demonstrated on tomato plants ( Lycopersicon spp.). Ten mites are placed on a thumbtack which is inserted through a test leaf; the number of mites that remain on the tack, as well as the distances mites moved onto the leaf, are recorded at designated time intervals. A sampling time of 2 h maximized the ability to detect differences in numbers of mites per thumbtack among three tomato taxa, and allowed detection of differences in distances traveled. The bioassay is relatively quick and simple, and it results in highly quantitative measures of resistance mediated by repellency. The bioassay should be useful for measuring plant resistance to a variety of flightless arthropods.
Effects of tumor necrosis factor alpha on leptin secretion and gene expression: relationship to changes of glucose metabolism in isolated rat adipocytes.

Effects of tumor necrosis factor alpha on leptin secretion and gene expression: relationship to changes of glucose metabolism in isolated rat adipocytes
Letter identification errors as a function of retinal input locus and positional variability

Retinal acuity differences are shown to account substantially for identification errors resulting when members of a dimensionally defined letter set (p, b, q, d) are singly presented at fixed positions within the foveal field for reduced durations. The error pattern can be altered by shifting the fixation point as little as 12 min 9 sec of visual angle. However, when letter position varies, the error distribution reflects dimensional information structure.
Psychiatrists and their prescribing practices

Abstract Of all the variables that influence the decision to treat psychiatric symptoms with medication, the characteristics of the physician have been studied the least. A survey questionnaire was sent to one-third of the Massachusetts Psychiatric Society membership; 48% responded. They were asked to note their prescribing practice for four common psychiatric symptoms (anxiety, depression, mood swing, and though disorder) at three levels of magnitude (mild, moderate, and severe). The results were evaluated with the respondent's age, sex, type of practice and treatment orientation acting as independent variables. At the mild and severe symptom extremes, there was generally little disagreement about the use of medication. In the moderate range, however, differences in ideology influenced practice significantly. Age and gender differences were also found to exert a significant influence.
Treatment Efficacy of Social Communication Skills Training After Traumatic Brain Injury: A Randomized Treatment and Deferred Treatment Controlled Trial

Abstract Dahlberg CA, Cusick CP, Hawley LA, Newman JK, Morey CE. Harrison-Felix CL, Whiteneck GG. Treatment efficacy of social communication skills training after traumatic brain injury: a randomized treatment and deferred treatment controlled trial. Objective To evaluate the efficacy of a replicable group treatment program to improve social communication skills after traumatic brain injury (TBI). Design Randomized treatment and deferred treatment controlled trial, with follow-up at 3, 6, and 9 months post-treatment. Setting Community. Participants Volunteer sample of 52 people with TBI who were at least 1 year postinjury, who received rehabilitation, and who had identified social communication deficits. Intervention Twelve weekly group sessions (1.5h each) to improve social communication. Main Outcome Measures The Profile of Functional Impairment in Communication (PFIC), Social Communication Skills Questionnaire–Adapted (SCSQ-A), Goal Attainment Scale (GAS), Craig Handicap Assessment and Reporting Technique–Short Form social integration and occupation subscales, Community Integration Questionnaire social integration and productivity subscales, and Satisfaction With Life Scale (SWLS). Results Independent samples t test analysis showed significant treatment effect compared with no treatment on 7 of 10 of the PFIC subscales (P range, .024 to Conclusions TBI subjects who received social communication skills training had improved communication skills that were maintained on follow-up. Overall life satisfaction for participants was improved.
Primary antiphospholipid antibody syndrome with mutations in the phospholipid binding domain of β2-glycoprotein I

β2-Glycoprotein I, an anionic phospholipid-binding 50-kDa plasma protein, circulates in the plasma at a concentration of 30–200 μg/ml. Its physiological role remains uncertain, but an important clue to this role is suggested by the finding that antibodies to this protein are frequently found in patients with antiphospholipid antibodies and thrombosis. β2-Glycoprotein I belongs to the complement control protein (CCP) superfamily with five CCP domains. The fifth CCP domain of β2-glycoprotein I has a unique structure and contains a stretch of positively charged amino acids that mediates the binding to phospholipids. This interaction may mediate the clearance of anionic phospholipid-containing surfaces from the circulation. Mutations in this domain affect its binding to phospholipids. We have identified a patient with primary antiphospholipid syndrome who is a compound heterozygous for two mutations in the fifth CCP. One mutation is located in exon 7 (codon 306), and the second mutation is in exon 8 (codon 316). The mutant β2-glycoprotein I was present in normal quantities in his plasma but did not bind to cardiolipin. He had recurrent deep vein thrombosis and pulmonary embolism at age 28 and a thrombotic stroke at age 35, with no other identifiable risk factor for a hypercoagulable state. This report offers some insight into the mechanism of formation of antiphospholipid antibodies and suggests the possible role of the deficiency of β2-glycoprotein I in the pathogenesis of thrombosis. Am. J. Hematol. 65:160–165, 2000. © 2000 Wiley-Liss, Inc.
Parthenogenetic lizards as vertebrate systems.

Unisexual (all-female) lizards of the genus Cnemidophorus are well suited for research in oogenesis, embryogenesis, nutrition, immunology, sex determination, genetics, and the effects of aging and exposure to pathogens and chemicals, in addition to evolutionary biology. Individuals produce clones by means of parthenogenesis, and both diploid and triploid partheno-gens exist. In addition, there are closely related bisexual (gonochoristic) species of Cnemidophorus. Advantages and disadvantages of maintaining laboratory colonies of Cnemidophorus are discussed.
Does nucleation theory apply to the formation of refractory circumstellar grains

It is pointed out that kinetic factors inherent in cosmic systems will prevent the attainment of an approximate equilibrium precondensation cluster distribution, and that therefore such systems will violate one of the most fundamental assumptions of nucleation theory. More importantly, it is shown that of the 11 refractory metal/metal oxide systems which have been studied experimentally none are consistent with the predictions of either classical nucleation theory or the Lothe-Pound modification. Since no valid method is known by which these deficiencies can be circumvented, it is concluded that nucleation theory cannot be made to work in expanding circumstellar shells. However, a stochastic, kinetic treatment which makes use of experimental and theoretical data for specific refractory systems does appear to be feasible.
Measurements Versus Predictions for the Rotordynamic Characteristics of a Five-Pad Rocker-Pivot Tilting-Pad Bearing in Load-Between-Pad Configuration

Rotordynamic data are presented for a rocker-pivot tilting-pad bearing in a load-between-pad (LBP) configuration for unit loads over the range [345, 3101 kPa] and speeds over the range [4k to 13k rpm]. The bearing was direct lubricated through a leading-edge groove with the following specifications: 5 pads, .282 preload, 60% offset, 57.87° pad arc angle, 101.587 mm (3.9995 in) rotor diameter, .1575 mm (.0062 in) diametral clearance, 60.325 mm (2.375 in) pad length. Dynamic tests were performed over a range of frequencies to investigate frequency effects on the dynamic-stiffness coefficients. Under most test conditions, the direct real parts of the dynamic stiffnesses could be approximated as quadratic functions of the excitation frequency and accounted for with the addition of an added mass matrix to the conventional [K][C] matrix model to produce a frequency-independent [K][C][M] model. Measured added mass terms in the loaded direction approached 60 kg. At low speeds, “hardening” direct dynamic stiffness coefficients that increased with increasing frequency were obtained that produced negative added-mass terms. No frequency dependency was obtained for the direct damping coefficients. The dynamic experimental results were compared to predictions from a bulk-flow CFD analysis. The static load direction in the tests was y. The direct stiffness coefficients Kxx and Kyy were slightly over predicted. Measured direct damping coefficients Cxx and Cyy were insensitive to changes in either load or speed in contrast to predictions of marked Cyy sensitivity for changes in the load. Only at the highest test speed of 13000 rpm were the direct damping coefficients adequately predicted. Measurable cross-coupled stiffness coefficients were obtained for the bearings with Kxy and Kyx being approximately equal in magnitude but opposite in sign — clearly destabilizing. However, the whirl frequency ratio was found to be zero at all test conditions indicating infinite stability for the bearing.Copyright © 2008 by ASME
Potential health implications of racial and ethnic disparities in meeting MTM eligibility criteria.

Abstract Background Previous studies have found that racial and ethnic minorities would be less likely to meet the Medicare eligibility criteria for medication therapy management (MTM) services than their non-Hispanic White counterparts. Objectives To examine whether racial and ethnic disparities in health status, health services utilization and costs, and medication utilization patterns among MTM-ineligible individuals differed from MTM-eligible individuals. Methods This study analyzed Medicare beneficiaries in 2004–2005 Medicare Current Beneficiary Survey. Various multivariate regressions were employed depending on the nature of dependent variables. Interaction terms between the dummy variables for Blacks (and Hispanics) and MTM eligibility were included to test whether disparity patterns varied between MTM-ineligible and MTM-eligible individuals. Main and sensitivity analyses were conducted for MTM eligibility thresholds for 2006 and 2010. Results Based on the main analysis for 2006 MTM eligibility criteria, the proportions for self-reported good health status for Whites and Blacks were 82.82% vs. 70.75%, respectively (difference = 12.07%; P P = 0.31), among MTM-eligible population. The difference between these differences was 7.23% ( P Conclusions Disparities in MTM eligibility may aggravate existing racial and ethnic disparities in health outcomes. However, disparities in MTM eligibility may not aggravate existing disparities in health services utilization and costs and medication utilization patterns. Future studies should examine the effects of Medicare Part D on these disparities.
Super DksAs: substitutions in DksA enhancing its effects on transcription initiation

At specific times during bacterial growth, the transcription factor DksA and the unusual nucleotide regulator ppGpp work synergistically to inhibit some Escherichia coli promoters (e.g. rRNA promoters) and to stimulate others (e.g. promoters for amino-acid synthesis and transport). However, the mechanism of DksA action remains uncertain, in part because DksA does not function like conventional transcription factors. To gain insights into DksA function, we identified mutations in dksA that bypassed the requirement for ppGpp by selecting for growth of cells lacking ppGpp on minimal medium without amino acids. We show here that two substitutions in DksA, L15F and N88I, result in higher DksA activity both in vivo and in vitro, primarily by increasing the apparent affinity of DksA for RNA polymerase (RNAP). The mutant DksA proteins suggest potential roles for ppGpp in DksA function, identify potential surfaces on DksA crucial for RNAP binding, and provide tools for future studies to elucidate the mechanism of DksA action.
Size distribution analysis of polymer latex systems by use of extrema in the angular scattering intensity

The angular position of the extrema of the vertically polarized scattering intensity has previously been utilized for a method of particle size analysis for systems of monodisperse, spherical, isotropic particles which conform to the Rayleigh-Gans-Debye theory. The consequences of a finite polydispersity, which is always present in real systems, was not assessed and the application of the method has resulted in erroneous characterization of some latex systems. This work is concerned with (1) reporting the effects of finite polydispersity on the method of analysis, (2) pointing out previous misuse of the method, and (3) introducing a method of analysis which is based on the position of the extrema but which also considers polydispersity and the exact Mie calculation. This method enables one to characterize a scattering system in terms of a modal diameter and a distribution-width parameter by utilizing prepared diagrams for a particular relative refractive index.
Mycobacterium tuberculosis Uses Host Triacylglycerol to Accumulate Lipid Droplets and Acquires a Dormancy-Like Phenotype in Lipid-Loaded Macrophages

Two billion people are latently infected with Mycobacterium tuberculosis (Mtb). Mtb-infected macrophages are likely to be sequestered inside the hypoxic environments of the granuloma and differentiate into lipid-loaded macrophages that contain triacylglycerol (TAG)-filled lipid droplets which may provide a fatty acid-rich host environment for Mtb. We report here that human peripheral blood monocyte-derived macrophages and THP-1 derived macrophages incubated under hypoxia accumulate Oil Red O-staining lipid droplets containing TAG. Inside such hypoxic, lipid-loaded macrophages, nearly half the Mtb population developed phenotypic tolerance to isoniazid, lost acid-fast staining and accumulated intracellular lipid droplets. Dual-isotope labeling of macrophage TAG revealed that Mtb inside the lipid-loaded macrophages imports fatty acids derived from host TAG and incorporates them intact into Mtb TAG. The fatty acid composition of host and Mtb TAG were nearly identical suggesting that Mtb utilizes host TAG to accumulate intracellular TAG. Utilization of host TAG by Mtb for lipid droplet synthesis was confirmed when fluorescent fatty acid-labeled host TAG was utilized to accumulate fluorescent lipid droplets inside the pathogen. Deletion of the Mtb triacylglycerol synthase 1 (tgs1) gene resulted in a drastic decrease but not a complete loss in both radiolabeled and fluorescent TAG accumulation by Mtb suggesting that the TAG that accumulates within Mtb is generated mainly by the incorporation of fatty acids released from host TAG. We show direct evidence for the utilization of the fatty acids from host TAG for lipid metabolism inside Mtb. Taqman real-time PCR measurements revealed that the mycobacterial genes dosR, hspX, icl1, tgs1 and lipY were up-regulated in Mtb within hypoxic lipid loaded macrophages along with other Mtb genes known to be associated with dormancy and lipid metabolism.
The spirit of oncology nursing care.

Cancer awakens the need to honour our spirit. The resiliency of the human spirit helps patients and families find strength and hope and move forward on their journey. As oncology nurses, we empower families by connecting with and sharing our own spirit, honouring and being present to their journey, and guiding them forward as they anticipate challenges ahead. Caring isn’t about doing for, but being there and being the wind behind the sails. When we connect with our spirit, we stay open to the unfolding mystery of life. Allow mystery and discovery in your life to drive your spirit of caring and to remind you to look for the rainbows.
Reproduction and developmental variability in the opisthobranchTenellia pallida

Pelagic and non-pelagic development occurs within a single population of the nudibranchTenellia pallida (Alder and Hancock) from South Carolina (USA). Both developmental types occurred simultaneously, under identical conditions, and without the aid of nurse eggs. Adults laid either ≈70 μm diameter eggs that hatched as pelagic (planktotrophic?) veligers in 68 to 122 h, or ≈100 μm diameter eggs that became well-developed veligers, metamorphosed within their egg capsules, and hatched as shelled juveniles in 140 to 190 h (15°C, 30‰ S). Adults that produced pelagic larvae laid more eggs per day and per egg mass and twice the daily egg volume produced by adults of the opposing type.
“Save the time of the surfer”: evaluating Web sites for users

A good web site has a purpose for the designer who wrote the page, the editor who maintains it and the Web surfer who finds it. One can think about this by paraphrasing and restating Ranganathan‘s Five Laws of Library Science, beginning with this one: “Web sites are for use.” A Web site without without a potential audience is pointless; a purposeless Web site will have no audience.
Predictors of survival after tricuspid valve surgery

Abstract The long-term survival rate of 74 consecutive patients who underwent multiple cardiac valve surgery including tricuspid valve surgery was analyzed to identify predictive preoperative clinical variables. Univariate analysis revealed that male sex (p
On closed orbit for a class of planar systems of high degree

For a class of planar polynomial differential systems of degreep+q, arising from biochemical reactions, there are given conditions of parameters under which the systems produce Hopf bifurcation with limit cycles appearing, or have no closed orbits.
The 11 ‐year pittsburgh experience with liver transplantation for hepatocellular carcinoma: 1981‐1991

Experience with liver transplantation over a period of 11 years at the University of Pittsburgh is presented. The application of liver transplantation to cases of hepatocellular carcinoma has changed considerably over this 11-year period with the sequential introduction of adjuvant and, more recently, neoadjuvant chemotherapy. Results with the combination of chemotherapy plus surgery appear to be better than results with either agent alone. Moreover, the early results with neoadjuvant therapy appear to be better than those achieved with adjuvant therapy. As a result of this experience, conceptual changes in the approach to the problem of hepatic cancer and the role of both chemotherapy and liver transplantation in its management have changed at the University of Pittsburgh. These changes are identified and discussed.
Monitoring mobility disorders at home using 3D visual sensors and mobile sensors

In this paper, we present PoCM2 (Point-of-Care Mobility Monitoring), a generic and extensible at-home mobility evaluation and monitoring system. PoCM2 uses both 3D visual sensors (such as Microsoft Kinect) and mobile sensors (i.e., internal and external sensors embedded with/connected to a mobile device such as a smartphone) for complementary data acquisition, as well as a series of analytics that allow evaluation of both archived and real-time mobility data. We demonstrate the performance of PoCM2 with a specific application developed for freeze detection and quantification from Parkinson's Disease mobility data, as an approach to estimate the medication level of the PD patients and potentially recommend adjustments.
Mycorrhizal dependency of Chihuahuan Desert plants is influenced by life history strategy and root morphology

Arbuscular mycorrhizal (AM) fungal infection was assessed for dominant Chihuahuan Desert annual and perennial plant species. Annuals were determined to have significantly less AM infection than their perennial counterparts. Additionally, annuals were shown to have significantly smaller fine root diameters than perennials. Within 15 of the 17 species examined, the presence of AM hyphae in a root segment was not a significant determinant of root diameter, indicating than in most plant species mycorrhizal infection is not directly promoting root diameter increases. The results of this survey show that the dominant plant species of the Chihuahuan Desert group into two categories: (i) short-lived annuals with thin roots and low AM dependency, (ii) longer-lived perennials with thick mycorrhizal roots.
Ionization of one-electron oxygen and fluorine projectiles by molecular hydrogen.

Cross sections for projectile ionization have been measured for hydrogenlike oxygen and fluorine ions incident on a molecular-hydrogen target over a projectile energy range of 0.5\char21{}2.5 MeV/amu. The experimental cross sections are compared to the plane-wave Born approximation (PWBA) and to the Glauber-approximation cross sections all of which were calculated for atomic hydrogen and multiplied by 2. The PWBA calculations have a projectile energy dependence similar to the measured cross sections but slightly underestimate them. The Glauber approximation also underestimates the measured projectile-ionization cross sections when the hydrogen target electrons are neglected, while it overestimates the measured cross sections when the effects of the hydrogen target electrons are included. The measured projectile-ionization cross sections for hydrogenlike ions incident on molecular hydrogen are approximately a factor of 2 smaller than previously reported projectile-ionization cross sections for hydrogenlike ions incident on helium. No cross sections are available for atomic hydrogen in this velocity and ion-charge regime.
Inhibition of tumor cell invasion by verapamil.

Verapamil, a calcium channel antagonist, inhibits murine B16 melanoma and colon adenocarcinoma C26 tumor metastasis by altering platelet aggregation [Tsuruo, T., et al. (1985) Cancer Chemother. Pharmacol., 14:30–33]. However, the role of calcium homeostasis in regulating several biochemical pathways implicated in other steps of the meta-static cascade suggests that calcium channel antagonists could also inhibit metastasis by other mechanisms. In this report, non-toxic doses of verapamil reversibly decreased human A375M and C8161 melanoma cell invasion and metastasis in a dose-dependent manner. Verapamil reduced cellular invasion and metastases by up to 96% (range 78–96%). Concomitantly, verapamil disrupts microtubule and microfilament organization and inhibits unidirectional cell migration but does not affect cellular adhesion to endothelial mono-layers or reconstituted basement membranes. In addition, tumor cells treated with verapamil have a decrease in mRNA of type IV collagenase, a proteinase important in tumor cell degradation of basement membranes. Collectively, these data offer additional evidence regarding the mechanisms of action of verapamil as an anti-metastatic agent.
Statistical analysis of the Ceriodaphnia toxicity test: Sample size determination for reproductive effects

An analysis of sample size requirements for the Ceriodaphnia dubia reproduction toxicity test is presented. Sample size requirements for detecting nominally specified biological effect sizes in the presence of different variance models are examined over a range of false positive error rates (α) and false negative error rates (β). Mean total young produced per female from control organisms in 53 separate toxicity tests yields a mean (22.52) and variance (68.25) that are used in sample size determinations. Results from these calculations demonstrate that in tests using the currently accepted sample size of 10 organisms per concentration, hypothesis-testing techniques are capable of detecting a range of 31 to 100% reproductive inhibition relative to controls. This wide range of minimum detectable inhibition values indicates that the ability to detect biologically significant levels of reproductive inhibition in this test is constrained by the statistical properties (i.e., power) associated with the currently accepted test protocol. It is suggested that the design of the Ceriodaphnia toxicity test be based not only on a minimum level of control reproductive output (as currently recommended), but also on the ability to detect a specified level of reproductive inhibition.
Effect of desirable fasting triglycerides on the postprandial response to dietary fat.

Background The National Cholesterol Education Program (NCEP) recently revised the “desirable” fasting triglyceride (TG) to Methods To evaluate the postprandial response to dietary fat, 50 studies were conducted in nonobese, normocholesterolemic subjects. Following an overnight fast, subjects consumed an oral fat load (70 g/m2), and postprandial triglyceride (ppTG) measurements were assessed at 2, 4, 6, and 8 hours. Subjects were divided by fasting TG cutpoints of 100 and 150 mg/dL. Results The prevalence of ppTG samples exceeding 200 mg/dL was significantly lower with fasting TG 100 mg/dL (n = 21) (125 mg/dL versus 249.8 mg/dL; p Conclusions Because ppTG-rich lipoproteins contribute to coronary heart disease risk, fasting TG
Inductive verification of data model invariants for web applications

Modern software applications store their data in remote cloud servers. Users interact with these applications using web browsers or thin clients running on mobile devices. A key issue in dependability of these applications is the correctness of the actions that update the data store, which are triggered by user requests. In this paper, we present techniques for au- tomatically checking if the actions of an application preserve the data model invariants. Our approach first automatically extracts a data model specification, which we call an abstract data store, from a given application using instrumented exe- cution. The abstract data store identifies the sets of objects and relations (associations) used by the application, and the actions that update the data store by deleting or creating objects or by changing the relations among the objects. We show that checking invariants of an abstract data store corre- sponds to inductive invariant verification, and can be done using a mapping to First Order Logic (FOL) and using a FOL theorem prover. We implemented this approach for the Rails framework and applied it to three open source applications. We found four previously unknown bugs and reported them to the developers, who confirmed and imme- diately fixed two of them.
An Efficiency Wage Approach to Reconciling the Wage Curve and the Phillips Curve

Abstract This study develops an efficiency wage model that generates a wage curve at the regional level and a Phillips curve at the national level, under the assumption that workers' efficiency depends on both regional and aggregate labor market conditions. An equation relating wages to unemployment and lagged wages is derived from the profit-maximizing behavior of firms, and it is demonstrated that the coefficient on lagged wages is less than 1 with regional data but equals 1 with aggregate data. In addition, there is an equilibrium relationship between unemployment and wages at the regional level, but not at the aggregate level.
A Rapid Method To Determine Sterol, Erythrodiol, and Uvaol Concentrations in Olive Oil

A rapid, accurate, and efficient method for determining the sterol, uvaol, and erythrodiol concentrations was developed to meet International Olive Council (IOC) certification criteria for extra virgin olive oil (EVOO). The unsaponifiable fraction of the sample (0.2 g) was separated with a diatomaceous earth column, and the sterol and triterpenic dialcohols were isolated with a novel base-activated silica solid-phase extraction (SPE) cartridge cleanup protocol. The improved method and the IOC method provided identical pass/fail results (n = 34) for each of the six sterol and erythrodiol/uvaol IOC criteria used to assess olive oil. This method was validated, and recoveries of stigmasterol (88%) and β-sitosterol (84%) were greater than previously published values obtained using the IOC method. This method requires approximately one-third the time required to complete the IOC method and has great utility for the rapid screening of EVOO to detect adulteration, false labeling, and an inferior product.
PROTECTION OF HIGHWAY WATER SUPPLIES.

State health departments have long recognized the necessity for the supervision of public water supplies and by continued effort have succeeded in securing adequate protection of the majority of these supplies. Work of this kind. has been at times very difficult of accomplishment and there are still cities whose water supplies cannot be classed as safe, but in those' states where an efficient sanitary engineering division is functioning as a part of the state health department the number of unsafe municipal water supplies is becoming less each year. The fact that the water in most of our cities is safe to drink gives the inhabitants of these cities a feeling of security and they do not realize that all of the waters which are found along the highways are not of the same satisfactory quality as that to which they have been accustomed in their own homes. We must recognize the fact that in spite of our educational work the average citizen has but a very hazy idea of the sanitary requirements of a safe water 'supply. If the water is clear, cold, and pleasing to' the taste the general public is satisfied that it is safe to drink, and
An algorithm for calculating the independence and vertex-cover polynomials of a graph

Abstract The independence polynomial, ω ( G , x ) = ∑ w k x k , of a graph, G, has coefficients, wk, that enumerate the ways of selecting k vertices from G so that no two selected vertices share an edge. The independence number of G is the largest value of k for which w k ≠ 0 . Little is known of less straightforward relationships between graph structure and the properties of ω ( G , x ) , in part because of the difficulty of calculating values of wk for specific graphs. This study presents a new algorithm for these calculations which is both faster than existing ones and easily adaptable to high-level computer languages.
Rational modification of an HIV-1 gp120 results in enhanced neutralization breadth when used as a DNA prime

Background The identification of phenotypic features of the HIV-1 envelope glycoprotein that correlate with neutralization breadth is an important goal of HIV vaccine research. Recently we compared the immunogenic potential of two gp120s differing in their ability to utilize CD4; B33 (highly macrophage topic) and LN40 (non-macrophage tropic). Using a DNA prime protein boost regimen in New Zealand White Rabbits, LN40-primed sera displayed enhanced breadth compared to the B33-primed group, with differences in immunogenicity between groups modulated by specific residues within and flanking the V3 loop and the CD4bs. To better understand the role of these residues in eliciting breadth, we introduced reciprocal mutations between LN40 and B33 at these critical positions.
Changes in social behavior of the male golden hamster accompanying photoperiodic changes in reproduction.

Abstract Testicular regression and decreased serum testosterone levels result when male hamsters are placed in a short-day photoperiod, and these changes are reversed after reexposure to long-days. The present study was undertaken to determine whether these physiological changes lead to modifications in social behavior in the male hamster. Animals in a nonstimulatory short-day (LD 6:18) or a stimulatory long-day (LD 14:10) photoperiod were observed every 3 weeks for 21 weeks. After 9 weeks, half of the LD 6:18 males were returned to LD 14:10 and showed rapid testicular recrudescence. The other half remained in LD 6:18 and showed a slower rate of testicular recrudescence. Assessment of aggression was accomplished by placing an intruder in the home cage of a test animal and recording latency to attack, decisive encounters, number of attacks, and number of aggressive postures. Dominance was evaluated in a neutral arena with opponents of different weights, using the same parameters. Scent-marking was recorded in response to both bedding from an intact male and bedding from an ovariectomized female in a clean cage. Short-day animals undergoing testicular regression showed heightened levels of aggression and an upward shift in their dominance status. Alteration of the photoperiod did not affect the pattern or number of scent marks. As animals underwent testicular recrudescence, there was a return to lower levels of aggression and to a lower dominance status. Males undergoing rapid testicular recrudescence also showed the most rapid decline in aggressive behaviors. These results suggest that levels of agonistic behavior in the male hamster are inversely related to serum testosterone levels. Scent-marking appears to be unreleated to androgen levels in the male hamster and its role in hamster social behavior remains unclear.
Low-threshold stripe geometry lasers by metalorganic chemical vapour deposition (MO-CVD)

We report low-threshold MO-CVD-grown GaAlAs DH (8260 A) lasers with shallow proton implantation delineated stripe widths of 4, 6 and 8 mm. At room temperature, a 125 μm device with a 6 μm stripe exhibited a 31 mA threshold and operated kink-free up to 15 mW/facet with a differential efficiency of 76%.
Carboxyglutamic acid (Gla) containing proteins of human calcified atherosclerotic plaque solubilized by EDTA. Molecular weight distribution and relationship to osteocalcin.

Abstract Proteins containing the calcium binding amino acid, γ-carboxyglutamic acid (Gla), are abundant in calcified human atherosclerotic plaque, but are detectable only at trace levels in the normal arterial wall and non-mineralized atherosclerotic lesions. These proteins have been incompletely characterized, and their role in the pathophysiology of atherosclerotis is not known. The present study sought to determine the overall molecular weight distribution of the calcified plaque Gla-protein fraction solubilized by EDTA deminerilization and the possible relationship of these proteins to the bone Gla-protein, osteocalcin. Calcified atheromata were demineralized with EDTA (0.5 M, pH 6.9) for 7 days and the dialyzed EDTA extract subjected to procedures which specifically labeled the protein-bound Gla-residues with tritium. The EDTA solubilized Gla-protein fraction (19.5% of the total Gla) was separated by gel filtration high performance liquid chromatography which demonstrated a single broad radiolabeled Gla-protein peak with an approximate molecular weight of 6000 daltons. In addition the EDTA solubilized atherosclerotic Gla-proteins could be distinguished from the bone Gla-protein, osteocalcin (molecular weight = 5 700 daltons), by reverse phase HPLC and specific radioimmunoassays for osteocalcin. It is concluded that the Gla-proteins of human calcified atherosclerotic plaque solubilized with EDTA demineralization consist of a heterogeneous 6000 dalton fraction, which is apparently unrelated to the bone Gla-protein, osteocalcin.
Inverse computation of cohesive fracture properties from displacement fields

The cohesive zone model (CZM) is a key technique for finite element (FE) simulation of fracture of quasi-brittle materials; yet its constitutive relationship is usually determined empirically from global measurements. A more convincing way to obtain the cohesive relation is to experimentally determine the relation between crack separation and crack surface traction. Recent developments in experimental mechanics such as photoelasticity and digital image correlation (DIC) enable accurate measurement of whole-field surface displacement. The cohesive stress at the crack surface cannot be measured directly, but may be determined indirectly through the displacement field near the crack surface. An inverse problem thereby is formulated in order to extract the cohesive relation by fully utilizing the measured displacement field. As the focus in this article is to develop a framework to solve the inverse problem effectively, synthetic displacement field data obtained from finite element analysis (FEA) are used. Fi...
Baffle-Drop Structure Design Relationships

A baffle-drop structure is a flow conveyance structure that can be used for transport of urban storm water down to underground storage tunnels. The water cascades down the structure from baffle to baffle and plunges into a pool at the bottom from where it is conveyed to the tunnel through an adit. The structure has been used successfully in a limited number of urban drainage schemes. However, its hydraulics and air entrainment characteristics are not fully understood. Using a series of laboratory experiments, an analysis has been tested and validated that may be used for design. The analysis provides a dimensionless relationship between key variables, including design discharge, shaft diameter, baffle spacing, and position of a vertical wall dividing the shaft in a dry and a wet portion. Using this relationship the shaft can be designed to maintain atmospheric pressure throughout its height with little or no air being entrained into the tunnel.