cssi/SciSciGPT-SciSciNet huggingface dataset:
Uranium concentrations and 238U/235U isotope ratios in modern carbonates from the Bahamas: Assessing a novel paleoredox proxy

Abstract In order to validate the use of 238U/235U as a paleoredox proxy in carbonates, we examined the incorporation and early diagenetic evolution of U isotopes in shallow Bahamian carbonate sediments. Our sample set consists of a variety of primary precipitates that represent a range of carbonate producing organisms and components that were important in the past (scleractinian corals, calcareous green and red algae, ooids, and mollusks). In addition, four short push cores were taken in different depositional environments to assess the impact of early diagenesis and pore water chemistry on the U isotopic composition of bulk carbonates. We find that U concentrations are much higher in bulk carbonate sediments (avg. 4.1 ppm) than in primary precipitates (avg. 1.5 ppm). In almost all cases, the lowest bulk sediment U concentrations were as high as or higher than the highest concentrations found in primary precipitates. This is consistent with authigenic accumulation of reduced U(IV) during early diagenesis. The extent of this process appears sensitive to pore water H2S, and thus indirectly to organic matter content. δ238/235U values were very close to seawater values in all of the primary precipitates, suggesting that these carbonate components could be used to reconstruct changes in seawater U geochemistry. However, δ238/235U of bulk sediments from the push cores was 0.2–0.4‰ heavier than seawater (and primary precipitates). These results indicate that authigenic accumulation of U under open-system sulfidic pore water conditions commonly found in carbonate sediments strongly affects the bulk U concentrations and 238U/235U ratios. We also report the occurrence of dolomite in a tidal pond core which contains low 234U/238U and 238U/235U ratios and discuss the possibility that the dolomitization process may result in sediments depleted in 238U. From this initial exploration, it is clear that 238U/235U variations in ancient carbonate sediments could be driven by changes in global average seawater, by spatial and temporal variations in the local deposition environment, or subsequent diagenesis. To cope with such effects, proxies for syndepositional pore water redox conditions (e.g., organic matter content, iron speciation, and trace metal distributions) and careful consideration of possible post-deposition alteration will be required to avoid spurious interpretation of 238U/235U data from ancient carbonate sediments.
E-business decision making by agreement

Gathering customer data over the Internet is largely limited to collecting the responses to a set of easily answerable questions, such as Yes/No questions and Likert scale questions. These data are then analyzed to identify customer trends or other items of interest to management. The data can be useful, but key to their usage is the application of suitable mathematical tools. Traditionally little more than standard statistics has been used in the analysis of ordinal, or category, data. This can be inaccurate and in some cases, misleading. This paper introduces measures of agreement and dissent to the field of eBusiness analysis and shows how ordinal data can be analyzed in more meaningful ways.
AUV navigation in the presence of a magnetic disturbance with an extended Kalman filter

This paper presents a novel extended Kalman filter (EKF) used for navigation of an autonomous underwater vehicle (AUV). The AUV contains a magnetic compass, which is susceptible to magnetic disturbances, and an angular velocity sensor, which exhibits drift if solely integrated to estimate heading. To address these problems, the presented EKF fuses the information from these sensors in order to produce a more accurate estimate of heading, and learns a heading bias in real-time. The presented method has two distinct advantages. First, the heading bias can correct for errors from a poorly calibrated magnetic heading sensor. Second, the angular velocity information improves heading estimation, especially in the presence of a magnetic disturbance. Because the AUVs presented here are designed to acquire magnetic field measurements, this second advantage is of particular importance. In both simulation and experimental testing, the presented EKF learned a calibration bias for the magnetic heading sensor and improved heading estimation in the presence of a magnetic disturbance.
Drug resistance conferred by mutations outside the active site through alterations in the dynamic and structural ensemble of HIV-1 protease.

HIV-1 protease inhibitors are part of the highly active antiretroviral therapy effectively used in the treatment of HIV infection and AIDS. Darunavir (DRV) is the most potent of these inhibitors, soliciting drug resistance only when a complex combination of mutations occur both inside and outside the protease active site. With few exceptions, the role of mutations outside the active site in conferring resistance remains largely elusive. Through a series of DRV–protease complex crystal structures, inhibition assays, and molecular dynamics simulations, we find that single and double site mutations outside the active site often associated with DRV resistance alter the structure and dynamic ensemble of HIV-1 protease active site. These alterations correlate with the observed inhibitor binding affinities for the mutants, and suggest a network hypothesis on how the effect of distal mutations are propagated to pivotal residues at the active site and may contribute to conferring drug resistance.
978 SECRETORY IGA ANTIBODIES IN HUMAN MILK AGAINST CANDIDA ALBICANS

Secretory IgA (SIgA) antibodies to Candida albicans have previously been detected in pooled human milk by immunofluorescence, and there is some evidence that these antibodies interfere with the adherence of that organism to human buccal epithelial cells (Arch Oral Biol 27:617, 1982). Little is known regarding the mucosal defense against this fungal agent in early infancy. Because of the occurrence of the fungus in the gastrointestinal tract, and the commonness of candidal infections during pregnancy, we hypothesized that high titers of SIgA antibodies to Candida albicans would be frequently present in human milk and would aid in the infant's mucosal defense against this fungus. Milk specimens, collected 2–4 days post-partum from 10 nursing mothers, were centrifuged to remove cells and examined for Candida-specific SIgA antibodies by a micromodification of an enzymelinked immunosorbent assay, utilizing a protein extract of Candid da albicans as the solid phase and an anti-secretory componenthorseradish peroxidase conjugate as the detector. Pooled human colostrum served as a reference standard (titer 1:25). Eight of the subjects studied displayed titers of secretory IgA antibodies to Candida which were >l:16. The range of titers was <1.1 to 1:460 (mean, 1:86; median, 1:32). High titers of SIgA antibodies to Candida albicans found in the majority of milk specimens examined suggest that these antibodies may defend the mucosa of the breast-fed infant against this common opportunistic agent.
Spinal amino acid release and repeated withdrawal in spinal morphine tolerant rats.

We used spinal microdialysis in awake rats to investigate whether the repeated withdrawal with naloxone during continuous spinal infusion of morphine would lead to a progressively greater spinal glutamate release and a more pronounced intrathecal tolerance. Rats received lumbar intrathecal (IT) infusion of morphine (IT-M: 20 nmol μl−1 h−1) or saline (IT-S: 1 μl h−1) continuously for 3 days. Both groups were further subdivided to receive intraperitoneal (i.p.) injection of naloxone (IP-N: 0.6 mg kg−1) or saline (IP-S: 3 ml kg−1) every 24 h after the beginning of IT infusion. Daily thermal escape latencies, withdrawal signs, the resting basal release of spinal amino acids before IP injection and the release immediately after the injection (evoked) were measured. Rats receiving IT morphine showed a maximum increase in thermal escape latency on day 1, after which this value declined, with the fastest decline observed in IT morphine+IP naloxone group. On day 1, no significant difference was observed among groups in the resting basal release of amino acids. Rats in IT morphine+i.p. naloxone group displayed a progressive increase in this value. The release was not significantly altered in other groups. For the IT-M+IP-N group, basal resting dialysate concentrations of Glu, Asp and Tau rose steadily over the 3-day infusion interval. No change in basal resting release was noted for any other treatment. Evoked release (after i.p. naloxone) in IT-M animals displayed a progressive increase over the three repeated exposures. Evoked release did not change significantly in other treatment groups. The degree of precipitated withdrawal significantly correlated with the increase in glutamate acutely evoked by i.p. injection. The present results show that periodic transient withdrawal of spinal opiate agonist activity leads to a progressive increase in glutamate outflow and withdrawal signs, in a manner consistent with an enhanced development of spinal tolerance. British Journal of Pharmacology (2003) 138, 689–697. doi:10.1038/sj.bjp.0705102
Health risk perceptions across time in the USA

Risk research has tended to focus on the elements of a risk that make it of more concern to the public or characteristics of the individual that change their risk perceptions. While these two lines of research have identified a number of important factors they have, for the most part, been isolated in time. This study begins to introduce time as a factor in risk perception research. Urban Americans were the focus of the study. The research was conducted over three years at six-month intervals. A mailed survey was sent to 250 individual household each survey period. Participants were asked about their perceptions of risk for Americans in general and for themselves and their families. They were asked to evaluate the overall risk environment compared to a year earlier and were asked to rank eight risk factors, again both for Americans in general and themselves and their families. Ordinal regression was the primary method of analysis. Participants perceived risk as increasing for each period of the study. The...
Ventricular Vulnerability in Diabetes and Myocardial Norepinephrine Release

Previously the authors have observed a reduction of the ventricular fibrillation threshold (VFT) in a mild diabetic model. This investigation examines the role of more severe hyperglycemia in altering the ventricular fibrillation threshold and how the sympathetic nervous system modulates the response. Alloxan diabetes was induced in eight male mongrel dogs 3–5 years of age (Group 2), for comparison with matched controls (Group 1). Hemoglobin A1c rose from 2.9 ± .4–7.8 ± .3% and body weight was maintained with daily insulin. After 1 year, anesthesia was induced with chloralose and an electrode catheter placed at the right ventricular apex. VFT was 41.7 ± 1.8 main Group 1 and 27.8 ± 2.1 ma in the diabetics of Group 2 (p < .001). There was significantly greater decline of VFT in response to epinephrine infusion in Group 2. The threshold in diabetics rose to normal levels after infusion of the beta-blocking agent, esmolol. Subsequently, the response of the cardiac sympathetic system was assessed during ventricular pacing at 200 beats/minute. Serial paired blood samples were taken from catheters in the aorta and coronary sinus for catecholamine assay by HPLC. Both groups had similar coronary blood flow responses by the thermal method, as well as changes in arterial pressure. While no change occurred in Group 1, a progressive rise of norepinephrine (NE) concentration was observed in coronary venous effluent of Group 2 (p < .01). The basal arterial-coronary sinus difference was −123 ± 52 pg/ml, which rose during pacing in Group 2 to a peak of −376 ± 9.3 pg/ml. Ischemia appeared unlikely in view of the normal myocardial lactate extraction and coronary blood flow response as well as morphologically intact mitochondria. The observations of this study are consistent with the view that enhanced ventricular vulnerability in diabetes is associated with altered sympathetic activity in myocardium.
Globalization and the values of volunteering as leisure.

Abstract Cultural globalization may be a way to foster the values or volunteering as a leisure experience. Volunteerism may offer one way to bring people together to address the problems of local communities as well as the global village. Defining volunteering is complicated because it is a cultural activity that is conditioned by multiple factors including ethnic traditions, religious beliefs, and legal regulations. In countries around the world, however, people in governmental as well as not for profit organizations are realizing the economic and social benefits of volunteering. An implication of globalization may be opportunities to share information about volunteering and how volunteers use their energy to supplement human capital as well as social services. Three related but distinct dimensions are discussed regarding volunteerism and how it relates to leisure and recreation including individual, organizational, and community aspects. In a globalized world where it is easy to become disillusioned wit...
Ammonium perchlorate gasification and combustion at high heating rates and low pressures

Mass-spectrometric and linear regression rate characterizations are reported, derived from CO2 laser pyrolyses of pressed NH2ClO4 (AP) at incident heat fluxes ranging from 25 to 4000 cal/sq cm sec. Product evolution-rate histories were obtained in vacuo by time-resolved (5 msec) mass spectrometry during (1) transient heat-up, and (2) subsequent quasi-steady vaporization (QSV). Vaporization induction times were obtained for (1); these, coupled with heat-transfer approximations neglecting thermochemical heat release, indicated that optical absorption at 10.6 microns dominated over conduction for heat fluxes much greater than 300. Conclusions applying in vacuo were: preferential desorption of NH3, with net accumulation of adsorbed HClO4, occurred during transient heat-up and onset of condensed phase decomposition (CPD), but preferential decomposition of adsorbed HClO4 (compared to NH3) occurred during QSV when CPD was significant. CPD was the dominant mode of QSV at moderate heat fluxes.
The infeasibility of self-regulating constant-current-fed class E power inverters

Because of their high operating efficiency, class E circuits have been shown to be useful in high-frequency power inverters and converters. Typical circuits are constant-fed, i.e. they require an RF choke in the DC-feed line, and must obtain load regulation by means of appropriate feedback control. A class E inverter with finite DC-feed inductance that provides perfect load regulation without feedback control has been suggested. However, such class E circuits generally have higher sensitivities to component variations (except load resistance) than do their constant-current-fed counterparts. Thus, the possibility of load-independent operation of constant-current-fed class E inverters is of interest. The authors show that there is no way to configure constant-current-fed E inverter so that it will exhibit load-independent properties except for a trivial circuit with zero output voltage. >
Molecular adsorption at well-defined electrode surfaces: benzene on Pd(1 1 1) studied by EC-STM and HREELS

Abstract The chemisorption of benzene at well-defined Pd(1 1 1) electrode surfaces in 0.1 M HClO 4 has been studied by a combination of electrochemistry, molecular resolution scanning tunneling microscopy, and high-resolution electron energy loss spectroscopy. At potentials within the double-layer region, a well-ordered Pd(1 1 1)-c(2√3×3)- rect -C 6 H 6 adlattice was formed in which the adsorbed benzene molecules are slightly tilted with respect to the metal surface. When the potential was decreased to values just inside the hydrogen evolution region, a third of the chemisorbed molecules were desorbed and a new ordered adlayer, Pd(1 1 1)-(3×3)-C 6 H 6 , was generated; in this less-densely packed phase, the coadsorption of water was indicated, and the aromatic molecules were chemisorbed more closely parallel to the surface. The potential-dependent structural and compositional transitions were found to be reversible. Structural models of the c(2√3×3)- rect and (3×3) adlattices are proposed.
Parental Notification and Family Counseling: Amendments to FERPA

In 1998, the Higher Education Reauthorization Act amended the 1974 Family Education Rights to Privacy Act (FERPA) by awarding institutions of higher education the option to notify parents when students have violated alcohol or drug policies. For family counselors, the recent amendment created an opportunity for collaboration between parents and universities that was considered illegal in the past. A case study of a family situation is presented followed by discussions on how the new amendment helps counselors work with families who have children or family members in college.
The Vanishing Health Care Safety Net: New Data on Uninsured Americans

New data obtained from the Census Bureau shows that the number of Americans without any health insurance increased by 1.3 million between 1989 and 1990, bringing the total number of uninsured to 34.7 million, more than at any time since the passage of Medicare and Medicaid 25 years ago. This increase coincided with a 10.5 percent increase in health spending, the second largest in the past three decades. The number of people covered by Medicaid grew by 3.1 million, due to a one-time expansion of eligibility mandated by Congress, but this was more than counter-balanced by a population growth of 3 million and a decrease of 1.3 million in people covered by private insurance. Had Medicaid not been expanded, the number of uninsured would have increased by 4.4 million. The increase in the uninsured affected virtually all parts of the nation. Seven states had increases of more than 100,000 persons each. Only Texas experienced a decrease of that magnitude, but still had the second highest rate of uninsurance of any state. Of the 1.3 million additional uninsured in 1990, 77 percent were male, 32 percent had family incomes in excess of $50,000 per year, and 74 percent had annual family incomes above $25,000. Fewer than 9 percent had incomes below the poverty line. The numbers of uninsured children and senior citizens fell slightly (but not significantly), while the number of uninsured working-age adults rose by 1.4 million. The number of uninsured workers in each of four of 20 major industry groups increased by more than 100,000 in 1990. None of the industry groups showed a significant decline in the number of uninsured. Among professionals, there were substantial numbers of uninsured doctors, engineers, teachers, college professors, clergy, and others, but all legislators and judges were insured. The data presented here largely predate the recession and understate current problems. In 1991 the number of uninsured will likely reach nearly 40 million. Also, these estimates are based on the number of people uninsured at a single time during 1990; a far higher number were temporarily uninsured at some point during the year. Moreover the Census Bureau survey ignores the problem of the underinsurance of at least 50 million insured Americans. Patchwork public programs are grossly inadequate to plug the holes. A national health program covering all Americans could assure access to care and contain costs.
Changing productive efficiency in telecommunications in the United States

Abstract The issue explored is whether incentive regulation in the telecommunications industry in the United States has resulted in an increase in productive efficiency. After providing an overview of the nature of incentive regulation, the methodology for measuring the effects of incentive regulation on productive efficiency is reviewed. This methodology is data envelopment analysis (DEA) and allows for the measurement of both technical efficiency and allocative efficiency of individual local exchange carriers. The results of empirically implementing the DEA approach indicate that in the aggregate there is little change in technical efficiency. In fact, average technical efficiency in 1989 was the same as in 1998. Next, while outputs continued to grow at about their historical rate across LECs, the sizeable increase in the two types of capital increased inputs well above their historical average rates for some LECs leading to short-run allocative inefficiency. On average, however, allocative efficiency shows no identifiable trend between 1988 and 1998. Finally, in the aggregate, total economic efficiency, what incentive regulation in the telecommunications industry in the United States was designed to promote, does not have a demonstrable trend between 1988 and 1998.
Microscopic origin of the two-sublattice model for antiferroelectric state

The macroscopic model proposed by Kittel for antiferroelectrics assumes two interpenetrating sublattices with antiparallel polarizations. Although the model can explain many properties, it does not provide microscopic lattice displacement patterns associated with these sublattices since the order parameter in the model is a volume-averaged quantity. We propose a model based on microscopic positioning of symmetry elements and use an order parameter field directly associated with the local dipoles, which can provide a more transparent definition for the sublattices used in the Kittel model. We also include nonlocal gradient interactions to model multidomain structures and domain walls in ferroelectrics.
Explanation for the amiable physicist

The Problems of Biology. By John Maynard Smith. Oxford University Press: 1986. Pp. 134. Hbk ?12.95, 19.95; pbk ?4.95, 6.95.
Environmental effects on crack tip processes at the atomic level

Abstract A model is described that is used to examine some aspects of liquid metal embrittlement in which the consequences of placing one type of atom (B) within a crack in another (A) are computed by atomic simulation methods. The energetics of the atomic interactions are based on an embedded atom method type potential that produces a regular solution between A and B. Systematic variation in the heat of mixing is used to examine the influence of this parameter on the A-B interfacial energies and the crack tip configuration. As long as B isable to wet A the crack closes onto a layer of B atoms inserted into the crack. For certain crystallographic orientations, and for one type of grain boundary, this closure creates a crack tip dislocation pair. This pair may be rather mobile. For other orientations the dislocation decomposes into partials which glide away leaving a relatively immobile configuration.
MAGNETO-OPTICAL MEDIA WITH HIGH KERR ROTATION AT SHORT WAVELENGTHS

Magneto-optical recording materials with high remanent Kerr rotation at short wavelengths were successfully obtained in a trilayer form by sandwiching NdCo amorphous films with an in-plane magnetization between TbFeCo amorphous films with strong perpendicular anisotropy and high coercivity. The effect of the NdCo thickness on the magnetic and magneto-optical properties of the trilayer medium was investigated systematically. The distribution of the magnetization direction in a trilayer NdCo amorphous alloy film was calculated to manifest the reorientation of the magnetization inside the NdCo layer through magnetic exchange coupling.
The effect of cigarette smoking on rabbit aortic elastase activity

Twenty rabbits were divided into three groups: (1) cage controls, (2) machine controls, and (3) cigarette exposed. The cigarette-exposed group was exposed to two 2-R1 reference cigarettes a day for 6 weeks on a Walton-II (Process and Instruments Corp., Brooklyn, N.Y.) smoking machine. Rabbits in the machine control group were placed in the smoking machine for the same period of time without cigarettes. Cage control animals were not placed in the smoking machine. Aortic elastase was significantly higher in the cigarette-exposed group (21.11 +/- 6.15) compared to both the cage control group (3.11 +/- 1.11) and machine control group (14.66 +/- 4.69). Aortic elastase in the machine control group was significantly higher in smoke-exposed rabbits than in both cage control and machine control rabbits. These data indicate that cigarette smoking increases aortic elastase activity in rabbits. If these data were to be extrapolated to humans, then patients with abdominal aortic aneurysms who smoke may have an accelerated rate of aneurysm growth or earlier rupture or both.
A shock tube and theoretical study on the pyrolysis of 1,4-dioxane.

The dissociation of 1, 2 and 4% 1,4-dioxane dilute in krypton was studied in a shock tube using laser schlieren densitometry, LS, for 1550–2100 K with 56 ± 4 and 123 ± 3 Torr. Products were identified by time-of-flight mass spectrometry, TOF-MS. 1,4-dioxane was found to initially dissociate via C–O bond fission followed by nearly equal contributions from pathways involving 2,6 H-atom transfers to either the O or C atom at the scission site. The ‘linear’ species thus formed (ethylene glycol vinyl ether and 2-ethoxyacetaldehyde) then dissociate by central fission at rates too fast to resolve. The radicals produced in this fission break down further to generate H, CH3 and OH, driving a chain decomposition and subsequent exothermic recombination. High-level ab initio calculations were used to develop a potential energy surface for the dissociation. These results were incorporated into an 83 reaction mechanism used to simulate the LS profiles with excellent agreement. Simulations of the TOF-MS experiments were also performed with good agreement for consumption of 1,4-dioxane. Rate coefficients for the overall initial dissociation yielded k123Torr = (1.58 ± 0.50) × 1059 × T−13.63 × exp(−43970/T) s−1 and k58Torr = (3.16 ± 1.10) × 1079 × T−19.13 × exp(−51326/T) s−1 for 1600 < T < 2100 K.
Recommendations and treatment options for nodules and other filler complications.

The authors have indicated no significant interest with commercial supporters in regards to this article.
"Where" matters: Location and Wi-Fi access

(2004). 'Where' matters: Location and Wi-Fi access. Journal of Urban Technology: Vol. 11, No. 1, pp. 1-28.
Life satisfaction and violent behaviors among middle school students

We explored relationships between violent behaviors and perceived life satisfaction among 2,138 middle school students in a southern state using the CDC Middle School Youth Risk Behavior Survey (MSYRBS) and the Brief Multidimensional Student Life Satisfaction Scale (BMSLSS). Logistic regression analyses and multivariate models constructed separately revealed significant race by gender results. Odds ratios and 95% confidence intervals were calculated for the variables of interest. Having ever carried a gun, ever carried a knife/club, physical fighting and physical fighting with need for medical treatment were associated (p ≤ .05) with reduced life satisfaction for specific race/gender groups, while controlling for SES and grade. Results suggest implications for school-community based violence prevention programs. Future research should consider measures of life satisfaction as a component of comprehensive assessments of middle school student violence and aggressive behaviors in fieldwork, intervention research and program evaluation.
Ethanol and acetaldehyde metabolism in the pregnant mouse.

Abstract Liver aldehyde dehydrogenase (ALDH) activity was found to be two-fold greater in pregnant (days 16–20 of gestation) mice than in non-pregnant controls. A subcellular fractionation revealed that the increase in ALDH activity was confined to the cystosolic fraction of the liver. Kinetic characterization of partially purified liver ALDH revealed similar K m values for either acetaldehyde or propionaldehyde in pregnant and non-pregnant animals. The similarity of apparent K m values suggests that the increase in cytosolic ALDH may involve induction of a normally present ALDH isozyme, rather than originating from synthesis of a new enzyme. Induction of liver ALDH was found to significantly decrease blood acetaldehyde concentrations in pregnant mice receiving 2.0 or 3.0 g/kg ethanol when compared to the respective control (non-pregnant) animals. However, differences in blood acetaldehyde levels measured in pregnant and control animals were not apparent when blood ethanol concentrations were below 40 μmol/ml.
Evidence for an axial oxygen-centered lattice fluctuation associated with the superconducting transition in YBa2Cu3O7.

The axial oxygen contributions to the Cu K-edge, polarized, extended x-ray-absorption fine structure of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ are analyzed from 10\ensuremath{\le}T\ensuremath{\le}105 K, using a novel approach in which the radial distribution function is directly calculated from model potentials. The best fit is obtained with a double-well potential with two nearly equally populated O(4) sites 0.13 \AA{} apart. The site separation decreases 0.02 \AA{} in a region near ${\mathit{T}}_{\mathit{c}}$. This perturbation in the structure is accompanied by a large increase of the tunneling frequency of \ensuremath{\sim}80 K between the two wells, suggesting a coupling between superconducting fluctuations and nonlinear phonons.
THE EVOLUTION OF THE CHEMICAL ISOTOPES AS AN ANALOG OF BIOLOGICAL EVOLUTION

Abstract A comparison is made between a biological adaptive landscape and the chemical isotopic landscape defined with three dimensions: the number of protons, the number of neutrons, and the stability of each isotopic nucleus. The courses of both biological and elemental evolution have been stochastic, leading from the simple to the complex; this is in agreement with statistical thermodynamic predictions. Analogs of mutation and natural selection occur in elementary evolution. The isotopic landscape can be assumed to have an a priori existence; at least the general features of the biological adaptive landscape also have an a priori existence. Both landscapes were occupied by spontaneous processes, analogous to diffusion.
Rectified quantized charging of gold nanoparticle self-assembled monolayers by arenedithiol linkages

Gold nanoparticle self-assembled monolayers were fabricated by a sequential anchoring mechanism with rigid arenedithiol chemical linkers. These particle surface assemblies exhibited well-defined quantized capacitance characters in aqueous solutions, and more importantly, in aqueous solutions, the voltammetric responses were rectified in the presense of hydrophobic anions, which was interpreted on the basis of a Randle's equivalent circuit where the particle-ion pairing formation led to the manipulation of electrode interfacial double-layer capacitance. The effective nanoparticle capacitances evaluated from the voltammetric measurements were consistent with those with the particles immobilized onto electrode sufraces by alkanedithiols. In addition, the nanoparticle electron-transfer kinetics was investigated by AC voltammetry and the rate constants were generally found of the order 10 3 s -1 , at least an order of magnitude greater than those with saturated alkyl spacers.
Ecosystem analysis using fuzzy set theory

Abstract Ecosystem studies of environmental quality are complicated by the imprecise nature of many ecological interrelationships and the subjectivity which is inherent in judgements by field observers. Many analyses of ecosystems require hierarchical decision-making processes which involve variables from social, economic and ecological sectors that are seemingly incompatible. Fuzzy set theory has been developed for and applied to problems involving complex systems like ecosystems. For example, government agencies who make habitat evaluations for wildlife can use techniques developed in fuzzy set theory for the combination of disparate variables that are required for decision-making at an ecosystem level. Another application of fuzzy set theory has generated a classification scheme for wetlands which is based on the knowledge of wetland experts. Fuzzy compartmentalization of ecosystem components allows greater diversity of behavior tha deterministic or probabilistic methods.
Different Plant Hormones Regulate Similar Processes through Largely Nonoverlapping Transcriptional Responses

Small-molecule hormones govern every aspect of the biology of plants. Many processes, such as growth, are regulated in similar ways by multiple hormones, and recent studies have revealed extensive crosstalk among different hormonal signaling pathways. These results have led to the proposal that a common set of signaling components may integrate inputs from multiple hormones to regulate growth. In this study, we tested this proposal by asking whether different hormones converge on a common set of transcriptional targets in Arabidopsis seedlings. Using publicly available microarray data, we analyzed the transcriptional effects of seven hormones, including abscisic acid, gibberellin, auxin, ethylene, cytokinin, brassinosteroid, and jasmonate. A high-sensitivity analysis revealed a surprisingly low number of common target genes. Instead, different hormones appear to regulate distinct members of protein families. We conclude that there is not a core transcriptional growth-regulatory module in young Arabidopsis seedlings.
HIV-Related Neuropsychiatric Changes: Concerns for Dental Professionals

HIV infection can cause a variety of neuropsychiatric changes. These changes and their effects on dental care delivery are discussed. A case report illustrates the behavioral changes of one patient.
Niobium-doped TiO2 films as window layer for chalcopyrite solar cells

Smooth and semitransparent Nbx Ti1–xOy (x = 0.03, y = 1.84–1.91) films have been prepared by reactive magnetron sputtering at temperatures below 420 K. Structural investigations by RAMAN-spectroscopy together with resistivity- and temperature-dependent Hall-measurements were used in order to analyze the film structure and the nature of the charge transport in this material. These films can be used as a window layer (TCO) for thin film solar cells. Cu(In,Ga)Se2 solar cells equipped with the new window layer keep their functionality which excludes first, the presence of strong energetic barriers and second, a strong interfacial recombination. The development of TiO2-based window layers is expected to make thin film solar cells less sensitive against corrosion after contact with humidity. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Tumor-specific peptides in cutaneous T-cell lymphoma: association with class I major histocompatibility complex and possible derivation from the clonotypic T-cell receptor.

We wished to identify and characterize tumor-associated class I peptides which could potentially serve as immunogens for an immunoprotective CD8 response in cutaneous T-cell lymphoma (CTCL). Candidate idiotypic peptides were identified from the third complementarity determining region (CDR3) of the clonotypic T-cell receptor (TCR) expressed on malignant T cells and native class I peptides were identified from CTCL cells. Idiotypic peptides were designed by sequencing of patients' CDR3 and identifying 9 amino acid peptides that could be accommodated in the peptide-binding motif of the class I alleles. Three candidate idiotypic peptides were synthesized and tested by measuring release of tumor necrosis factor-α (TNF-α) from autologous CD8 cells. Native peptides were acid-eluted from class I molecules on CTCL lymphocytes, fractionated, tested in the TNF-α assay and sequenced. Two unique idiotypic peptides were specifically recognized by autologous CD8 cells from CTCL patients. In addition, a native peptide eluted from class I molecules of CTCL tumor cells was identified, in the protein data base, as a novel molecule with partial sequence homology to the conserved portion of the patient's TCR. This homology was used to construct an extended native peptide sequence that was immunogenic for CD8 cells from both CTCL patients. Our results demonstrate that peptides derived from the TCR can be used as tumor-specific immunogens that are recognized by CD8 cells. Moreover, novel class I peptides isolated from the tumor cell also serve as immunogens. These peptides might form the basis of an anti-tumor vaccine for immunotherapy of CTCL. Int. J. Cancer 76:304–311, 1998.© 1998 Wiley-Liss, Inc.
Combustion of unsupported methanol/dodecanol mixture droplets at low gravity

Experiments are reported on the combustion of free or unsupported methanol/dodecanol mixture droplets in a reduced gravity environment. The experiments were conducted in a drop tower. The Grashof number (based on drop diameter) in the moving frame of reference was on the order of 10 exp -5 for the period of droplet burning. Combustion of the mixture droplets was characterized by a multi-stage process indicative of diffusion controlled burning. The flame was not visible during the first stage because of the lighting used, but was visible (and spherical) in the final stage. The results suggested that the mixture droplets did not extinguish. By contrast, methanol droplets consistently extinguished. Microexplosions were not observed for mixtures with initial concentrations of equal volumes of methanol and dodecanol. However, most of the droplets containing initially 75 percent (by volume) of methanol exploded. The initiation of microexplosion, as defined by the occurrence of homogeneous nucleation within the droplet, is explained by comparing the calculated nonlinear variation of superheat limit with composition for a methanol/dodecanol mixture with the boiling point of dodecanol.
Defining and identifying early onset bipolar spectrum disorder.

Early onset bipolar spectrum disorder (EOBPSD) is difficult to diagnose because of symptom overlap with other disorders and nearly ubiquitous comorbidity. A thorough assessment of EOBPSD should include the following: 1) a timeline of the child’s development, from birth to present, showing the episodic nature of EOBPSD; 2) a structured clinical interview determining comorbidity and differential diagnosis; 3) a family history genogram to ascertain familial loading and environmental stressors, which informs case conceptualization; 4) depression and mania rating scales to assess symptom severity and track treatment outcome; 5) global rating scales to obtain cross-informant data and inform broad-based treatments; and 6) a current mood log to document baseline functioning and track treatment outcome. Examples of a timeline, family history genogram, and current mood log are presented. This comprehensive approach to assessing EOBPSD, a severe and possibly lifelong disorder, is strongly advocated. No scale, instrument, or technique alone is adequate to diagnose EOBPSD.
Isolation and biological activity of mammalian helical polyribosomes.

Abstract The injection of lasiocarpine into rats rapidly induces long, compact helical polyribosomal structures in liver cells. Because lasiocarpine produces a breakdown of most of the pre-existing polysomes at the same time that the helices appear, it is possible to isolate the helices in a relatively pure fraction, as demonstrated by electron microscopy. The helices retain their characteristic ultrastructure during their isolation. They are 500 to 600 A thick, may reach one micron in length and contain as many as 120 ribosomes, which are extremely tightly packed. There seem to be four to five ribosomes per turn of the helix. The helices fall apart under the effect of low doses of ribonuclease, of EDTA, or of puromycin, into ribosomes or ribosomal subunits. When [3H]leucine is injected into lasiocarpine-treated rats, isotopically labeled nascent polypeptide chains are found in the very heavy polysomal peak, which is a practically pure fraction of helices. The nascent chains are released by puromycin. When purified preparations of helices are tested in a cell-free system without the addition of any exogenous messenger RNA's, during the first ten minutes they incorporate [14C]phenylalanine into polypeptide chains at a rate comparable to that found in normal liver polysomes. Whereas the amino acid incorporation by normal liver polysomes ceases after 20 to 30 minutes, due to a breakdown of the polysomes, the uptake of amino acids by isolated helices continues for at least one hour. Cycloheximide and puromycin both affect the system in a way similar to that seen with normal polysomes. Helices thus appear to be functioning polysomes. Their very long length could be due to unusually long messenger RNA's.
Underwater implosion of glass spheres

Underwater implosion experiments were conducted with thin-wall glass spheres to determine the influence that structural failure has on the pressure pulse. Four experiments were conducted with glass spheres having an outside diameter of 7.62cm, thickness of 0.762mm, and an estimated buckling pressure of 7.57MPa. The experiments were performed in a pressure vessel at a hydrostatic pressure of 6.996MPa. The average peak pressure of the implosion pressure pulse was 26.1MPa, measured at a radial distance of 10.16cm from the sphere center. A computational fluid structure interaction model was developed to assess how the failure rate of the glass structure influences the pressure time history. The model employed a specified glass failure sequence that is uniform in time and space. It was found that for the conditions of the test, a glass failure rate of 275m∕s provided a reasonable representation of the test data. The test data and the model results show that the failure time history of the structure has a signi...
Assembly of the head of bacteriophage P22: x-ray diffraction from heads, proheads and related structures.

Abstract We have used electron microscopy and small-angle X-ray diffraction to study the three principal structures found in the head assembly pathway of Salmonella phage P22. These structures are, in order of their appearance in the pathway: proheads, unstable filled heads (which lose their DNA and become empty heads upon isolation), and phage. In addition, we can convert proheads to an empty head-like form (the empty prohead) in vitro by treating them with 0.8% sodium dodecyl sulfate at room temperature. We have shown that proheads are composed of a shell of coat protein with a radius of 256 A, containing within it a thick shell or a solid ball (outer radius 215 A) of a second protein, the scaffolding protein, which does not appear in phage. The three other structures studied are all about 10% larger than proheads, having outer shells with radii of about 285 A. Empty heads and empty proheads appear identical by small-angle X-ray diffraction to a resolution of 25 A, both being shells about 40 A thick. Phage appear to be made up of a protein shell identical to that in empty heads and empty proheads, within which is packed the DNA. Some details of the DNA packing are also revealed by the diffraction pattern of phage. The inter-helix distance is about 28 A, and the hydration is about 1.5 g of water per g of DNA. Certain aspects of the pattern suggest that the DNA interacts in a specific mariner with the coat protein subunits on the inside edge of the protein shell. Thus, the prohead-to-head transformation involves, in addition to the loss of an internal scaffold and its replacement by DNA, a structural transition in the outer shell. Diffraction from features of the surface organization in these structures indicates that the clustering of the coat protein does not change radically during the expansion. The fact that the expansion occurs in vitro during the formation of empty proheads shows that it is due to the bonding properties of the coat protein alone, although it could be triggered in vivo by DNA -protein interactions. The significance of the structural transition is discussed in terms of its possible role in the control of head assembly and DNA packaging.
Dare to care: Shipment consolidation reduces not only costs, but also environmental damage

Abstract Companies interested in greening their supply chains quickly realize that carbon and energy waste represents an expense, and thus minimizing this expense not only brings in truckloads of money, but also helps save the environment. This paper demonstrates that shipment consolidation, a powerful logistics strategy that combines two or more small shipments into an aggregate load to be dispatched on the same vehicle, can help mitigate carbon and energy waste. Specifically, a Discrete-Time Based Shipment ConsoLidation (DTB-SCL) policy and a new method to calculate CO2 emissions associated with the dispatch of a vehicle are introduced. In addition, an optimization model with the objective of maximizing combined economic and environmental savings is developed in this study. It is shown that, among other benefits, the higher use of transportation capacity decreases environmental damage, one goal of the DTB-SCL policy. The mechanics of the mathematical models are illustrated by numerical examples, and sensitivity analyses are conducted to provide managerial insights that might help companies come to better decisions that are environmentally responsible.
Applying service learning to computer science: attracting and engaging under-represented students

This article describes a computer science course that uses service learning as a vehicle to accomplish a range of pedagogical and BPC (broadening participation in computing) goals: (1) to attract a diverse group of students and engage them in outreach to younger students to help build a diverse computer science pipeline, (2) to develop leadership and team skills using experiential techniques, and (3) to develop student attitudes associated with success and retention in computer science. First, we describe the course and how it was designed to incorporate good practice in service learning. We then report preliminary results showing a positive impact of the course on all pedagogical goals and discuss the implications of the results for broadening participation in computing.
Sulfur amino acid metabolism in infants on parenteral nutrition.

Abstract In the infant on parenteral nutrition, cysteine supplementation has been suggesteddue to low levels of hepatic cystathionase activity limiting synthesis from methionine. We have examined the plasma concentrations of sulfur amino acids in four groups of post-surgical infants requiring parenteral nutrition receiving (A) a low methionine + cysteine + taurine formula, (B) a high methionine formula (non-steady state), (C) a high methionine formula (steady state), and (D) a high methionine + cysteine formula. Plasma methionine concentrations were above the normal reference range (2.2–4.9 micromole/dL) of normal breast-fed infants in Groups B (15.9 ± 10.7 micromole/dL) and D (5.7 ± 1.9 micromole/dL) and at the upper limit for Group C (4.9 ± 1.7 micromole/dL). Total cysteine/cystine concentrations (normal reference range, 10.2–20.4 micromole/dL) were highest in Groups A (18.9 ± 3.5 micromole/dL) and D (16.8 ± 5.3 micromole/dL) that received cysteine HCI supplementation, and lowest in Group B (8.6 ± 3.7 micromole/dL) that received no cysteine in non-steady state. All plasma free cystine concentrations were below the normal reference range (3.6–6.8 micromole/dL). Plasma taurine concentrations were not significantly different among the four groups and all were within the normal reference range (0.6–16.2 micromole/dL). The strikingly elevated methionine and low total cysteine/cystine values in Group B suggested the existence of a feedback loop of methionine conversion below the level of homocysteine. Equilibrium of methionine and cysteine/cystine plasma concentrations did occur, in time. Parenteral cysteine administration resulted in a greater proportion of plasma free cysteine concentration, but not cystine. The proportion of free to bound cysteine/cystine, as well as the proportion of free cystine to cysteine, was not normal during parenteral nutrition with or without cysteine HCI supplementation. Little benefit in plasma concentrations was derived from cysteine HCI supplementation to a high methionine formulation.