cssi/SciSciGPT-SciSciNet huggingface dataset:
Limit of centrifugal separation in a free vortex

Two vortex experiments are cited that show that the common analysis of centrifugal separators does not adequately predict the separation of small particles in j et-driven swirl separators. The common analysis ignores the interference of the particle with the vortex flow in cases where the flow deviates from the solid vortex type. This interference, in connection with viscous effects, causes substantial fluid pressure forces opposing the separation of the particle. With the viscous effects approximated by analogy with straight flow conditions, the limit for the separation of particles in a free vortex is derived. It becomes apparent that particles with a density much higher than that of the flow medium can move toward the vortex center instead of being separated. In zones where the flow deviates from the free vortex conditions, the inward movement may be stopped resulting in the stabilization of the particles. The present considerations pertain quite generally to the movement of small particles in curved flow's.
Hodgkin's disease — the role of radiation therapy in advanced disease

Summary The success of radiation therapy (XRT) in the management of early-stage Hodgkin's disease (HD) has led to its use in a variety of programs for the management of advanced disease. This article includes discussion of these roles of radiation in advanced disease: 1) use of XRT as an adjuvant after chemotherapy; 2) use of XRT to convert patients who are 'partial responders' (PRs) after chemotherapy to 'complete responders' (CRs); 3) use of XRT as an integrated component of combined modality therapy; 4) use of XRT as a 'salvage' treatment after failure of primary chemotherapy; and 5) incorporation of XRT into programs of high-dose therapy with autologous stem cell (or marrow) rescue. 1) Randomized trials of adjuvant XRT after completion of chemotherapy in advanced disease have been conducted by the Southwest Oncology Group (SWOG), German HD Study Group, and the European Organization for the Research and Treatment of Cancer/Group Pierre Marie Curie (EORTC/GPMC). The SWOG study shows improvements in diseasefree survival, but not overall survival with the addition of XRT. The German Study Group trial was negative, but the number of patients reported in the abstract of the trial was too small to be conclusive. The EORTC/GPMC study has not been reported. 2) Both the SWOG and EORTC/GPMC trials treated TRs' with XRT. Results in both show conversion to CR in > 80% of patients. Conversion to CR was most likely for patients with just minimal residual disease after chemotherapy. 3) Planned XRT in advanced disease (especially bulky sites) may permit reduction in chemotherapy doses (e.g., the Stanford V chemotherapy program) and maintain excellent outcome (freedom-from-progression >80%). Reduction in total doses of chemotherapy as well as dose and extent of radiation should limit potential long-term toxicity. 4) Very selected patients with asymptomatic limited nodal relapse may be 'salvaged' with XRT, but published reports include only a small number of patients and this should not be considered a standard approach. 5) XRT may be used as total body, total lymphoid, or local field in highdose therapy programs. Since HD at relapse is still often a local-regional problem, local field irradiation is probably the most rational approach to use in this setting. Recent Stanford data show an improvement in outcome with the inclusion of local field treatment in these patients.
Synergism of interleukin 7 with the thymocyte growth factors interleukin 2, interleukin 6, and tumor necrosis factor α in the induction of thymocyte proliferation

Abstract The role of previously defined thymocyte (Thm) growth factors in interleukin (IL)-7-induced Thm growth has not been fully elucidated. Therefore, experiments were designed to examine the capacity of IL-7 to: (i) directly induce Thm proliferation in the absence of experimental and known physiologic costimulators of Thm mitogenesis, and (ii) synergize with other Thm growth factors in supporting Thm proliferation. The data indicate that IL-7 is directly mitogenic for Thm; that is, IL-7 induces Thm proliferation in the absence of experimental comitogens such as concanavalin A, phytohemagglutinin, and phorbol myristate acetate and in the presence of neutralizing antibodies to murine IL-lα, IL-1β IL-2, IL-2 receptor (IL-2R)(p55), IL-2R(p70), IL-4, IL-6 and tumor necrosis factor (TNF). We also tested previously described Thm growth factors, i.e., IL-2, IL-4, IL-6 and TNF-α, for the capacity to synergize with IL-7 in Thm growth. Our results indicate that IL-2, IL-6, and TNF-α, but not IL-4, synergize with IL-7 in supporting Thm proliferation. These data suggest that IL-7 functions alone and in a synergistic fashion with other cytokines to regulate Thm growth.
Comparison of Residual Glomerular Function in Experimental Papillary Necrosis and Renal Infarction

The purpose of this study was to examine the course of residual glomerular function in two models of renal ablation both with equivalent degrees of nephron reduction (1 1/3 nephrectomy). The remnant group underwent right nephrectomy and infarction of one third of the left kidney, yielding constant proportions of remnant deep and superficial nephrons, while the bromoethylamine (BEA) group underwent right nephrectomy and chemical ablation by BEA (50 mg intravenously [IV]) of the deep nephrons of the left kidney, leaving superficial nephrons. Ten weeks following ablation, greater whole kidney permselective defects indicative of worse injury occurred in the remnant group compared with the BEA group, as manifested by increased excretion of total protein (.65 ± .14 v .23 ± .04 g/d [65 ± 14 v 23 ± 4 mg/24 h]; P v 9.0 ± 3.4 × 10 −4 ; P v 3.6 ± 1.2 × 10 −4 ; P GC ) were elevated similarly in the ablated groups compared with the control group. Based on the differences in the two models, the site of the increased proteinuria in the remnant group could be the deep nephrons and/or the nephrons adjacent to the scar.
Reduction of haloperidol-induced side effects by ACP-103 in healthy volunteers

Background/Aims A novel serotonin 2A (5-HT2A) receptor inverse agonist, ACP-103, was tested to determine the potential of ACP-103 to inhibit central nervous system side effects produced by haloperidol. Methods Healthy male volunteers participated in a randomized, double blind, placebo-controlled, single dose crossover study. All subjects received a single dose of haloperidol (7.5 mg) in combination with either a single dose of placebo or a single dose of ACP-103 (100 mg). The washout period between treatment combinations was two weeks. Results Haloperidol caused measurable akathisia in 13 of 18 subjects and induced approximately a 3-fold increase in prolactin secretion. ACP-103 treatment caused a measurable and temporally consistent decrease in haloperidol-induced akathisia compared to placebo treated subjects as measured by the Barnes Akathisia Scale. ACP-103 significantly reduced haloperidol-induced hyperprolactinemia. The pharmacokinetics of haloperidol and ACP-103 were not affected by their co-administration. No serious adverse events were reported. Conclusions Data suggest that ACP-103, when co-administered with existing antipsychotic drugs, may reduce their side effects and expand their range of efficacy. ACP-103 is being developed as an adjunctive therapy for schizophrenia and as a therapy for treatment-induced dysfunction in Parkinson's disease. Clinical Pharmacology & Therapeutics (2005) 77, P98–P98; doi: 10.1016/j.clpt.2005.01.004
Random selection of points distributed on curved surfaces.

Monte Carlo simulation is widely used in medical physics to obtain realistic solutions to radiation transport problems involving complex geometries. An important step is the random selection of the initial point in space from which the primary photon or charged particle originates. In many practical cases, the primary-particle sites are distributed over curved surfaces. The author describes general sampling techniques that can be used to randomly choose the trajectory origin for sources distributed over any smooth surface that can be parametrically represented as a function of two variables. The source distribution need not be uniform. Implementation of these methods is particularly straightforward for surfaces enclosing simple convex volumes such as spheres and ellipsoids.
What is the participant's good? A neglected ethical question in psycho-social research

The primary ethical hazard of research with human subjects derives from researchers’ use of participants for purposes that are not participants’ own. While ethical standards in biomedical research, such as clinical drug trials, require that the foreseeable benefits to participants outweigh the risks, psychosocial researchers have neglected to consider the ethically relevant benefits of research interactions. This paper examines how assumptions about risk/benefit ratios have shaped qualitative social science research and institutional review practices. Drawing on two ethically important moments from research interviews, the author argues that ignoring the potential good of the research encounter obscures the complex reality of research interactions, impedes thoughtful ethical decision-making in the interview situation, and precludes a comprehensive ethical accounting of psychosocial research.
Preferential loss of central (trunk) adiposity in adolescents and young adults after laparoscopic gastric bypass

Abstract Background An increasing number of young people are developing severe obesity with adult-like co-morbidities and undergoing bariatric surgery. Although a number of studies have described major weight loss after bariatric surgery, none have examined the proportions of lean body and fat mass lost or the potentially more important issue of changes in regional fat mass distribution after laparoscopic gastric bypass surgery. Methods Five morbidly obese females (mean age 18) were evaluated by standard anthropometric measures and dual energy x-ray absorptiometry at baseline and 1 year after bariatric surgery. The mean and SD values for the anthropometric and dual energy x-ray absorptiometry body composition variables were calculated, and the differences were evaluated using paired t tests. Results Significant body mass index and weight loss were seen in all subjects at 1 year, with the percentage of excess weight loss at 63.4%. Overall fat mass loss exceeded lean mass loss by threefold in this cohort ( P P = .03). Conclusion These results have demonstrated the preferential loss of central adiposity in morbidly obese young women after 1 year of surgical weight loss and may be more informative than anthropometric measurements alone. Given the association between central adiposity and the risk of subsequent cardiovascular disease, these results are suggestive of reduced cardiac risk.
Activated sludge primary biodegradation of polychlorinated biphenyls

The results of this study demonstrate that commercial PCB mixtures which contain predominantly mono- and dichlorobiphenyls readily undergo primary biodegradation under the experimental conditions employed. The data also illustrates that as the levels of tri-, tetra-, and pentachlorobiphenyls increase, the degradation rates decrease accordingly. This resistance of the more highly chlorinated biphenyls, particularly those containing 5 or more chlorine atoms per molecule, explains in part their detection as residues in weathered biological and environmental samples.
Repeated cocaine enhances ventral hippocampal‐stimulated dopamine efflux in the nucleus accumbens and alters ventral hippocampal NMDA receptor subunit expression

Dopaminergic neurotransmission in the nucleus accumbens is important for various reward-related cognitive processes including reinforcement learning. Repeated cocaine enhances hippocampal synaptic plasticity, and phasic elevations of accumbal dopamine evoked by unconditioned stimuli are dependent on impulse flow from the ventral hippocampus. Therefore, sensitized hippocampal activity may be one mechanism by which drugs of abuse enhance limbic dopaminergic activity. In this study, in vivo microdialysis in freely moving adult male Sprague–Dawley rats was used to investigate the effect of repeated cocaine on ventral hippocampus-mediated dopaminergic transmission within the medial shell of the nucleus accumbens. Following seven daily injections of saline or cocaine (20 mg/kg, ip), unilateral infusion of N-methyl-d-aspartate (NMDA, 0.5 μg) into the ventral hippocampus transiently increased both motoric activity and ipsilateral dopamine efflux in the medial shell of the nucleus accumbens, and this effect was greater in rats that received repeated cocaine compared to controls that received repeated saline. In addition, repeated cocaine altered NMDA receptor subunit expression in the ventral hippocampus, reducing the NR2A : NR2B subunit ratio. Together, these results suggest that repeated exposure to cocaine produces maladaptive ventral hippocampal-nucleus accumbens communication, in part through changes in glutamate receptor composition. A behaviorally sensitizing regimen of cocaine (20 mg/kg, ip 7 days) also sensitized ventral hippocampus (hipp)-mediated dopaminergic transmission within the nucleus accumbens (Nac) to NMDA stimulation (bolts). This was associated with reduced ventral hippocampal NR2A:NR2B subunit ratio, suggesting that repeated exposure to cocaine produces changes in hippocampal NMDA receptor composition that lead to enhanced ventral hippocampus–nucleus accumbens communication.
Resident fishes and macrobenthos in mangrove-rimmed habitats: evaluation of habitat restoration by hydrologic modification

An impounded area (Cabbagehead Bayou) in Upper Tampa Bay, Florida, was studied for 13 mo prior to and 22 mo after berm removal. Sampling for small fish and macrobenthos was conducted both at Cabbagehead Bayou and at a nearby control site, Double Branch Bay. Before and After Control and Impact (BACI) analyses, as well as similarity indices, were used to evaluate faunal characteristics in control versus impacted areas. Berm removal drastically changed periodicity of water cover in the impacted site, with the previously impounded site becoming almost entirely exposed during low tide. Fish abundances, biomass, and mean monthly number of species decreased in Cabbagehead Bayou after tidal flow was established as compared to when it was impounded. Responses of macrofauna varied among taxa, but total amphipod and polychaete abundance displayed a relative increase in the impacted site after berm removal. BACI analyses indicated that the relationship between mean values for almost all polychaete and amphipod taxa in the impacted and control sites changed significantly after berm removal. Additional differences were apparent in BACI analyses, which showed a significant change in the relationship of fish abundance and biomass at both sites for prebreach vs post-breach samples. The changes in relationships were generally not indicative of convergence of control and impacted sites, however. Community similarity of fish, amphipod, and polychaete assemblages increased during the last year of the post-breach sampling but remained generally very low. These findings suggest that distinct faunal responses to alteration of tidal periodicity can be detected within less than 2 yr after reestablishment of tidal flow. However, attainment of close correspondence to control conditions for certain fauna may require more than 22 mo. Therefore, future studies attempting to document recovery of restored wetlands may benefit from extended duration.
DRAP: a Robust Authentication protocol to ensure survivability of computational RFID networks

The Wireless Identification and Sensing Platform (WISP) from Intel Research Seattle is an instance of Computational RFID (CRFID). Since WISP tags contain sensor data along with their IDs, the authentication of these tags should be different than the ones found in typical RFID networks. Moreover, there can be a situation where an adversary may create more collisions at the link layer to initiate the de-synchronization attack. This in turn may result in DoS attack or system failure and may increase the system response time. In this paper, we propose a De-synchronization attack resistant Robust Authentication Protocol (DRAP) for WISP networks. Our proposal offers a lightweight solution to defend against major security attacks, including de-synchronization and DoS attacks. This protocol can return desynchronized tags and readers to their synchronous state. Therefore, it provides robustness and ensures survivability. We evaluate DRAP protocol in a simulated WISP environment and report the results in this paper.
An Erythroid-Specific Chromatin Opening Element Reorganizes β-Globin Promoter Chromatin Structure and Augments Gene Expression

Abstract ABSTRACT In erythroid tissues the chromatin structure of the β-globin gene locus is extensively remodeled. Changes include the formation of DNase I hypersensitive sites (HSs) over the promoters of actively expressed genes. To test the hypothesis that such “opening” of promoter chromatin structure is important for β-globin gene expression, we placed a 101-bp erythroid-specific hypersensitive-site forming element (HSFE) from the core of LCR HS4 immediately upstream of a minimal β-globin gene promoter. We then studied the effects of this element alone and in combination with other cis-acting elements on globin gene chromatin structure and gene expression in MEL cells and transgenic mice. Single or tandem HSFEs increased the size of the portion of the promoter accessible to DNase digestion, increased the proportion of promoters in an accessible conformation, and increased gene expression approximately 5-fold. These were equivalent to expression levels attained using a 2.8-kb μLCR construct. Inclusion of the LCR HS2 enhancer did not increase expression further. In transgenic mouse fetal liver cells the HSFE increased average expression 2.5-fold compared to the minimal promoter alone. These results indicate that a small cis-acting element is capable of remodeling local β-globin promoter chromatin structure and producing expression similar to that seen with a μLCR construct.
Incorporation of radioactivity from thymidine into mammalian glucose and glycogen.

Abstract 1. Glycogen and DNA were isolated by CsCl density-gradient centrifugation from livers of mice injected with [ 14 C]thymidine or [ 14 C]thymine while in specified nutritional states. Amounts of radioactivity found in glycogen varied with feeding patterns and reached levels far exceeding those in DNA. Polysaccharide labeling occurred in normally fed animals, but was heaviest in previously fasted ones that were fed prior to injection and were therefore actively synthesizing both glucose and glycogen. Glycogen labeling was 10-fold greater after [Me- 14 C]thymidine than after [2- 14 C]thymidine. 2. Chromatography of acid hydrolysates of the radioactive glycogen and response of the product to glucose oxidase showed all of the radioactivity to be in glucose. 3. The similarity of these findings to those we have made in the flatworm indicates that in widely separated animal species substantial amounts of radioactive label from catabolized exogenous DNA precursor molecules can be incorporated into glucose and then into glycogen. Polysaccharide thus labeled in vivo may, in a number of experimental circumstances, be mistaken for newly synthesized DNA.
Reality versus models: what we learned from acoustic control experiments

The development of active acoustic control experiments demonstrates the need to calibrate our view of the physical world with regular testing. We started with a desire to use feedback-based active control on acoustic systems with a system model based on the wave equation and the opinion that all work would flow smoothly from that model of physical reality. We have now realized that the hardest issues associated with active acoustic control are not well described by our simplistic initial model. Physical testing is the vehicle through which we tested our initial model. With physical testing and experimentation, we have focused on those elements of acoustics that are most important to the success of our acoustic control methods. The control experiment caused a change in research direction from control design to actuator design.
Microelectrode Sensing of Adenosine/Adenosine-5′-triphosphate with Fast-Scan Cyclic Voltammetry

Adenosine and adenosine-5′-triphosphate (ATP) are important extracellular signaling molecules. Here, we studied adenosine and ATP using fast-scan cyclic voltammetry at carbon-fiber microelectrodes. Although ATP and adenosine have similar oxidation potentials, ATP oxidation current was highly dependent on buffer pH and divalent cation concentrations but adenosine current was not. Therefore, they can be distinguished by adding a divalent cation chelator or calibrating electrodes at different pH values. The enzymatic degradation of adenosine by adenosine deaminase was monitored in a mixture of adenosine and ATP in presence of EDTA (ethylenediaminetetraacetate). This sensing method is promising for enzyme kinetics or in vitro studies.
Photoperiodic Reversibility of Diapause Induction in an Insect

The diapause of the pink bollworm is under photoperiodic control. Diapause is prevented when the dark phases of the daily photoperiod are 8 to 10 hours in duration. If the dark period is extended to 12 hours, diapause is induced. Intercalation of 8- or 10-hour nights may reverse the diapause induction caused by exposure to photocycles having 12-hour dark phases. The 10-hour night was much more effective in reversing induction than the 8-hour night. The intensity of diapause, in part, appeared to be dependent on the previous photoperiodic experiences of the test animals.
Natural resource‐collection work and children's schooling in Malawi

Abstract This paper presents results of research that investigates if long hours of work spent by children in fuel wood and water-collection activities, i.e., natural resource-collection work, influence the likelihood that a child aged 6–14 attends school. Potential endogeneity of resource-collection work hours is corrected for, using two-stage conditional maximum likelihood estimation. Data from the 1997–1998 Malawi Integrated Household Survey (IHS) conducted by the Malawi National Statistics Office (NSO) in conjunction with the International Food Policy Research Institute (IFPRI) are used. The study finds that Malawian children are significantly involved in resource-collection work and their likelihood of attending school decreases with increases in hours allocated to this work. The study further shows that girls spend more hours on resource-collection work and are more likely to be attending school while burdened by this work. Consequently, girls may find it difficult to progress well in school. However, girls are not necessarily less likely to be attending school. Results further show that presence of more women in a household is associated with a lower burden of resource-collection work on children and a higher probability of children's school attendance. Finally, the research shows that children from the most environmentally degraded districts of central and southern Malawi are less likely to attend school and relatively fewer of them have progressed to secondary school compared to those from districts in the north.
The efficacy of heating low-pressure H2 in a microwave discharge

The relative ease with which a low-pressure hydrogen stream may be heated in an electrical discharge suggests that such a system be considered in current efforts to develop thrusters for spacecraft orbit raising purposes. In this work a detailed model of a microwave discharge in flowing, low-pressure hydrogen is used to interpret and clarify experimental measurements of atom concentration, electron energy, and electron density. The radially averaged, constant-pressure model accurately reproduces the experimental data and also calculated the rates of a number of gas-heating and wall-heating processes as well as rates of energy deposition into coolant and working fluid streams. The calculated gas-heating rates indicate that the gas heating is due primarily to the thermalization of the energetic atoms produced by dissociation of H2 via excitation of theb 3∑ + state. The calculations also indicate that the energy flux to the quartz tube is significantly influenced by Lyman and Werner band radiation and by heterogeneous atomic recombination processes and, to a much lesser degree, by electron-ion recombination processes. The fraction of power input which is ultimately transferred to the gas stream is a decreasing function of the power input and varies from 0.24 to 0.12.
Chefs' opinions of restaurant portion sizes.

CONDRASKY, MARGE, JENNY H. LEDIKWE, JULIE E. FLOOD, AND BARBARA J. ROLLS. Chefs’ opinions of restaurant portion sizes. Obesity. 2007;15:2086 –2094. Objectives: The objectives were to determine who establishes restaurant portion sizes and factors that influence these decisions, and to examine chefs’ opinions regarding portion size, nutrition information, and weight management. Research Methods and Procedures: A survey was distributed to chefs to obtain information about who is responsible for determining restaurant portion sizes, factors influencing restaurant portion sizes, what food portion sizes are being served in restaurants, and chefs’ opinions regarding nutrition information, health, and body weight. The final sample consisted of 300 chefs attending various culinary meetings. Results: Executive chefs were identified as being primarily responsible for establishing portion sizes served in restaurants. Factors reported to have a strong influence on restaurant portion sizes included presentation of foods, food cost, and customer expectations. While 76% of chefs thought that they served “regular” portions, the actual portions of steak and pasta they reported serving were 2 to 4 times larger than serving sizes recommended by the U.S government. Chefs indicated that they believe that the amount of food served influences how much patrons consume and that large portions are a problem for weight control, but their opinions were mixed regarding whether it is the customer’s responsibility to eat an appropriate amount when served a large portion of food. Discussion: Portion size is a key determinant of energy intake, and the results from this study suggest that cultural norms and economic value strongly influence the determination of restaurant portion sizes. Strategies are needed to encourage chefs to provide and promote por
Univalent and Bivalent Ligands of Butorphan: Characteristics of the Linking Chain Determine the Affinity and Potency of Such Opioid Ligands†

Bivalent morphinan compounds containing ester linkers were synthesized and their binding affinities at the mu, delta, and kappa opioid receptors determined. Addition of methyl groups adjacent to the hydrolytically labile ester linkage increased stability while only partially affecting binding affinity. The resulting bivalent ligands with optimized spacer length and structure show potent binding profiles with the most potent compound (4b), having K(i) values of 0.47 nM for both the mu and kappa opioid receptors, and 4a, having K(i) values of 0.95 and 0.62 nM for the mu and kappa receptors, respectively. Both 4a and 4b were partial agonists at the kappa and micro receptors in the [(35)S]GTPgammaS binding assay.
Cytological studies in the genus Leucaena Benth.

In twelve Leucaena taxa examined, the chromosome numbers were found to be n=26, 28 and 52. Six species and one subspecies have n=26, two species n=28 and three species n=52. Chromosome numbers in L. collinsii Britton and Rose (n=26), L. diversifolia (Schlecht.) Benth. ssp. diversifolia Pan et Brewbaker (n=52), L. pallida Britton and Rose (n=52) and L. retusa Benth. (n=28) were reported for the first time. The meiosis was regular in all the diploids and in most tetraploids. Multivalents were found in some tetraploids. The chromosome pairing in some species hybrids showed that species genomes in the genus Leucaena were very similar cytologically. Besides geographical and ecological isolation, polyploidy has played a very important role in the evolution of the genus.
Policy Regimes and Policy Change

The evolution of public policies in the United States has been characterized as a process involving long periods of stability followed by abrupt episodes of substantial change. In this project, we identify strands in the literature and synthesize policy theories into a policy regime model useful in explaining both stability and change. This model focuses on power arrangements, policy paradigms and organization - factors that operate to maintain long periods of stability. We demonstrate how stressors - catastrophic events, economic crises, demographic changes, shifts in modes of production, and others - impact policy regimes and create pressures for change. We argue that the process of policy regime change - the abrupt episodes of substantial change - occurs with changes in the policy paradigm, alterations in patterns of power and shifts in organizational arrangements. The old policy regime disintegrates and the new one emerges with a new policy paradigm, new patterns of power and new organizational arrangements that operate to maintain long periods of stability.
Interactive Toxicity of Aluminum and Acidity to Early Life Stages of Brook Trout

Abstract The influences of exposure to aluminum and increased acidity on mortality, growth, behavior, and biochemical responses of brook trout Salvelinus fontinalis were evaluated as a function of developmental stage. Eyed eggs and young brook trout were exposed until 30 d after hatching in proportional diluters to pHs of 4.5, 5.5, and 7.2, with and without aluminum (300 μg/L); 37-d-old brook trout that had been held in experimental control water since hatching were exposed to these same conditions for 30 d. Exposure conditions (i.e., aluminum and calcium concentrations and pH) simulated conditions in some headwater lakes and streams in the northeastern United States. Adverse effects on exposed brook trout generally increased as pH decreased from 7.2 to 4.5 and potentiation of effects by aluminum occurred at pHs of 5.5 to 7.2. However, embryos and fish older than 36 d were more tolerant of acidic conditions and aluminum than were larvae less than 15 d old. We conclude that the adverse effects on mortality...
An Introduction to Teacher Retirement Benefits

Abstract Like most other state and local government employees, teachers participate primarily in defined benefit pension plans whose benefits are largely based on final average salaries and length of service. Such pensions have been replaced in many private sector firms by defined contribution pensions. A number of questions have arisen about the feasibility and desirability of continuing to rely on defined benefit pensions for teachers. This article provides a brief history of teacher pensions and an overview of teacher retirement benefits today, including differences in the legal and economic context for public and private sector pensions that are important considerations in plan design. It then introduces issues related to financial sustainability, teacher mobility, and teacher shortages. The article concludes with an overview of key differences between traditional defined benefit and defined contribution plans and raises the possibility of adopting a “hybrid” kind of plan that includes features from b...
Accidental parabolics in the mapping class group

In this paper we discuss the behavior of the Gromov boundaries and limit sets for the surface subgroups of the mapping class group with accidental parabolics constructed by the author and A. Reid (2006). Specifically, we show that generically there are no Cannon-Thurston maps from the Gromov boundary to Thurston's boundary of Teichmiiller space.
Depletion of nucleoporins from HeLa nuclear pore complexes to facilitate the production of ghost pores for in vitro reconstitution.

During cell division, Nuclear Pore Complexes (NPCs) are broken down into protein subcomplexes that are the basis for reassembly in daughter cells. This is the driving force for the establishment of an in vitro reconstitution system to study aspects of NPC reassembly. In this study, nuclear envelope (NE) was isolated from HeLa cells. NE was treated with increasing concentrations of heparin to extract nucleoporins (Nups) for the production of “ghost pores” which are pores severely deficient in Nups, while still containing Pore Membrane proteins (POM) needed to anchor the NPC. Ghost pores have been subjected to incubation with previously stripped Nups and some re-binding has been shown to occur by western blot analysis. This in vitro assay provides a powerful tool to investigate the protein–protein interactions of NPC reassembly from a human cell line. Through a better understanding of the process of NPC reassembly, we can continue to piece together the puzzle of this macromolecular structure. It is most advantageous to establish a straightforward reconstitution procedure at the mammalian level.
Non-subjective cataract analysis and its application in space radiation risk assessment

Experimental animal studies and human observations suggest that the question is not whether or not prolonged space missions will cause cataracts to appear prematurely in the astronauts, but when and to what degree. Historically the major impediment to radiation cataract follow-up has been the necessarily subjective nature of assessing the degree of lens transparency. This has spurred the development of instruments which produce video images amenable to digital analysis. One such system, the Zeiss Scheimpflug slit lamp measuring system (SLC), was incorporated into our ongoing studies of radiation cataractogenesis. It was found that the Zeiss SLC measuring system has high resolution and permits the acquisition of reproducible images of the anterior segment of the eye. Our results, based on about 650 images of the rats lens, and followed over a period of 91 weeks of radiation cataract development, showed that the Integrated Optical Density (IOD) of the lens correlated well with conventional assessment with the added advantages of objectivity, permanent and transportable records and linearity as cataracts become more severe. This continuous data acquisition, commencing with cataract onset, can proceed through more advanced stages. The SLC exhibits much greater sensitivity reflected in a continuously progressive severity despite the artifactual plateaus in staging which occur using conventional scoring methods. Systems such as the Zeiss SLC should be used to monitor astronauts frequent visits to low earth orbit to obtain a longitudinal data-base on the influence of this activity on the lens.
Ionization Energy and Electronic Structure of Polycytidine

Ribonucleic acid (RNA) polycytidine (poly rC) homopolymer thin films were prepared on highly oriented pyrolytic graphite (HOPG) substrates. The films were grown from aqueous solution directly in a vacuum in multiple steps with use of an electrospray (ES) deposition system. Before poly rC deposition and after each deposition step the sample was characterized with X-ray and ultraviolet photoemission spectroscopy (XPS, UPS). Evaluation of the UP-spectra sequence allowed the determination of ionization energy and highest occupied molecular orbital (HOMO) electronic structure, as well as the charge injection barriers between HOPG and poly rC. Comparison with earlier results on polyadenosine (poly rA) indicates significant differences between ionization energies (poly rC: 8.1 eV; poly rA: 6.8 eV) and orbital alignment at the graphite interface. The larger ionization energy of poly rC results in a larger hole injection barrier and a smaller electron injection barrier relative to the HOPG Fermi level.
Lanthanide modified semiconductor photocatalysts

Lanthanide ion modified semiconductor photocatalysts have been explored for photocatalytic degradation of organic pollutants, dye molecules, for photo-splitting of water under both ultra-violet (UV) and visible light conditions. This review provides an in-depth analysis of lanthanide ion semiconductor photocatalysts with focus on titania based photocatalysts. The emphasis is on delineating the underlying factors responsible for the enhanced activities observed by several research groups and in providing guidance to researchers in this area.
Glutathione conjugation and conversion to mercapturic acids can occur as an intrahepatic process.

By catalyzing the reaction of electrophilic compounds with the sulfhydryl group of glutathione, the glutathione S‐transferases play physiologically important roles in the detoxication of potential alkylating agents. The glutathione S‐conjugates thus formed are transported out of cells for further metabolism by γ‐glutamyltransferase and dipeptidases, ectoproteins that catalyze the sequential removal of the glutamyl and glycyl moieties, respectively. These ectoproteins are not found in all cells, but are localized predominantly to the apical surface of epithelial tissues. The resulting cysteine S‐conjugates can be reabsorbed by specific cell types, and acetylated on the amino group of the cysteinyl residue by intracellular N‐acetyl‐transferases, to form the corresponding mercapturic acids (N‐acetylcysteine S‐conjugates). Mercapturic acids are then released into the circulation and delivered to the kidney for excretion in urine, or they may undergo further metabolism. Mercapturic acid biosynthesis is general...
Legal Status and Educational Transitions for Mexican and Central American Immigrant Youth

This study uses the Survey of Income and Program Participation to infer the legal status of Mexican and Central American immigrant youth and to investigate its relationship with educational attainment. We assess differences by legal status in high school graduation and college enrollment, decompose differences in college enrollment into the probability of high school graduation and the probability of high school graduates' enrollment in college and estimate the contributions of personal and family background characteristics to such differences. Results show that undocumented students are less likely than documented students to both graduate from high school and enroll in college, and differences in college enrollment cannot be explained by family background characteristics. We conclude that legal status is a critical axis of stratification for Latinos.
EXCEPTIONAL SEIFERT GROUP ACTIONS ON R

We show that every group action on ℝ of the fundamental group of an exceptional Seifert fibered space M corresponds to an action on the order tree determined by the space of leaves of a foliation on M.
Effects of predator training on behavior and post-release survival of captive prairie dogs (Cynomys ludovicianus)

Reintroduction of captive animals to the wild is a conservation strategy that has rarely succeeded. For many species, the blame has been placed on ineffective post-release behavior. In particular, predation on newly released animals can be devastating. To deal with this problem, biologists have initiated programs of pre-release predator training. However, the success of these programs as a function of long-term post-release survival has yet to be measured. The development of effective antipredator behavior is known to be dependent upon experience. In social species, this experience may involve hearing alarm vocalizations, observing a conspecific interacting with a predator, or encountering a predator in the presence of an experienced group member. Here, we examine the effects of training captive juvenile black-tailed prairie dogs (Cynomys ludovicianus) with presentations of black-footed ferret, red tailed hawk, prairie rattlesnake predators, and a nonpredator control (cottontail). Training consisted of presenting appropriate alarm vocalizations during predator exposure. Playbacks of alarm vocalizations enhanced antipredator behavior toward these predators. Results revealed that training had an immediate and lasting effect on juveniles prior to release to the wild and that these differences appeared to promote post-release survival.
Disordered immune function in patients with polyglandular failure.

A standard assessment of immunity was accomplished in 15 patients with the polyglandular failure syndrome and compared to similar studies in appropriate healthy controls. The patients exhibited decreased delayed cutaneous responsiveness and increased serum levels of immunoglobulins G and A. Complement fixing antibody titers to a number of common viruses were equivalen to those observed in controls, but titers to Coxsackie B4 and B5 viruses were decreased in patients. The decreased antibody titers to Coxsackie B4 and B5 represent an alteration in host protection which is of possible importance in the etiology of polyglandular failure.
Immunostimulatory Properties of the Emerging Pathogen Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is a multiple-antibiotic-resistant opportunistic pathogen that is being isolated with increasing frequency from patients with health-care-associated infections and especially from patients with cystic fibrosis (CF). While clinicians feel compelled to treat infections involving this organism, its potential for virulence is not well established. We evaluated the immunostimulatory properties and overall virulence of clinical isolates of S. maltophilia using the well-characterized opportunistic pathogen Pseudomonas aeruginosa PAO1 as a control. The properties of CF isolates were examined specifically to see if they have a common phenotype. The immunostimulatory properties of S. maltophilia were studied in vitro by stimulating airway epithelial and macrophage cell lines. A neonatal mouse model of pneumonia was used to determine the rates of pneumonia, bacteremia, and mortality, as well as the inflammatory response elicited by S. maltophilia infection. Respiratory and nonrespiratory S. maltophilia isolates were highly immunostimulatory and elicited significant interleukin-8 expression by airway epithelial cells, as well as tumor necrosis factor alpha (TNF-α) expression by macrophages. TNF-α signaling appears to be important in the pathogenesis of S. maltophilia infection as less than 20% of TNFR1 null mice (compared with 100% of wild-type mice) developed pneumonia and bacteremia following intranasal inoculation. The S. maltophilia isolates were weakly invasive, and low-level bacteremia with no mortality was observed. Despite the lack of invasiveness of S. maltophilia, the immunostimulatory properties of this organism and its induction of TNF-α expression specifically indicate that it is likely to contribute significantly to airway inflammation.
A VLSI-based Gaussian kernel mapper for real-time RBF neural networks

An analog VLSI circuit approach to a radial basis function (RBF) neural network is explored. For each of a number of reference pattern templates, the circuit calculates the Euclidean distance between that template and an unknown point, and maps each distance to a point on the Gaussian surface of that template. Then, these points may either be added in order to form the basis for an RBF approximator or laterally inhibited to form the basis for an RBF classifier. The circuitry for this network has been implemented in 2-micron CMOS technology, and will form the bases for truly parallel and simultaneous standalone neural networks that function in real time without intervention from conventional computers. >
Potholes and Molehills: Bias in the Diagnostic Performance of Diffusion-Tensor Imaging in Concussion

The use of nonindependent reference and control groups in “pothole” analysis has led to a substantial overestimation of the diagnostic utility of diffusion-tensor imaging for mild traumatic brain injury in much of the literature.
What Do Employment Specialists Really Do? A Study on Job Development Practices:

This study examined the extent to which employment specialists implemented the job development practices recommended in the research literature when assisting job seekers with intellectual or developmental disabilities. Self-reported data were collected through a Web-based survey from 163 employment specialists from 74 employment programs in 28 states. Questions focused on the following four clusters of activities: Getting to know job seekers, finding job openings, engaging employers to hire, and facilitating transition to a job. Findings showed that some employment specialists self-reported practices conflicted with the practices advocated in the literature. On the basis of our findings, we recommended a greater emphasis on implementing job development activities recommended in the literature as well as furthering research on effective, evidence-based practices.
Two Koreas and public health: ‘First, do no harm’

In Khang’s insightful article regarding public health in North and South Korea, the author suggested that ‘militant’ reaction against North Korea could harm public health efforts.1 Likewise, ‘militant’ international policies exist that are clearly harmful to public health in North Korea. For example, despite the ongoing public health crisis in North Korea, the country remains under economic sanctions from the USA, Japan and the United Nations.2 Epidemiological studies have consistently shown that economic sanctions lead to dramatic increases in morbidity and mortality.3–5 Economic sanctions are particularly harmful to the most vulnerable segments of the targeted country’s population.5 Indeed, economic sanctions have been called a ‘tool of warfare’ because of their devastating impact on health and human rights.6 Therefore, the continuation of economic sanctions in North Korea is unacceptable from a public health standpoint. Another policy, albeit an unofficial one, that has harmed public health in North Korea is the use of humanitarian aid for political leverage. For example, the Bush administration withdrew food aid from North Korea in 2008 citing deficiencies in aid monitoring.7 This was done despite significant improvements in the quality of aid monitoring in North Korea through the years and assurance from on-the-ground aid personnel that the vast majority of the food aid was reaching the intended beneficiaries.7,8 Furthermore, nutritional surveys have shown that food aid has significantly improved children’s nutritional status in North Korea.9 Although the official US policy is that humanitarian aid is to be provided based solely on need, the withdrawal of food aid in 2008 to gain political concessions from North Korea is consistent with a longstanding pattern of using aid for political aims by US administrations.7 Unfortunately, this unofficial policy continues to harm vulnerable North Koreans today under the Obama administration.10 Khang asserted that the public health community could contribute to preventing war and improving health in the two Koreas.1 We should also insist that our governments practice the fundamental medical principle: ‘First, do no harm’.
Effect of microporous layer on MacMullin number of carbon paper gas diffusion layer

Abstract The effect of the microporous layer (MPL) and wet proofing on the MacMullin number has been evaluated for a custom series of Toray TGP-H-060 carbon paper gas diffusion layer (GDL). Complementary characterizations for these GDLs were performed by using scanning electron microscopy (SEM) images, pore size distribution (PSD) and fuel cell performance. The GDLs were customized by the addition of a microporous layer (MPL) and the treatment of, either or both, the substrate and MPL with 10% and 40% hydrophobic agent. SEM images correlated very well with the data shown for PSD. Distinction between the substrate layer and the MPL were clearly shown as two different slopes in the integral distribution and two different peaks in the differential distribution. The MacMullin number increased with increase in wet proofing but decreased with the addition of the MPL. The MacMullin number is a key parameter that contains the missing information for the path length in GDLs, which is generally approximated with the Bruggeman expression. The results provided an overview for the interpretation of the combined effect of the substrate and MPL properties as well as the cell operating conditions.