cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of a Glycyl Radical Enzyme Bacterial Microcompartment Pathway in Rhodobacter capsulatus .

Bacterial microcompartments (BMCs) are large (∼100-nm) protein shells that encapsulate enzymes, their substrates, and cofactors for the purposes of increasing metabolic reaction efficiency and protecting cells from toxic intermediates. The best-studied microcompartment is the carbon-fixing carboxysome that encapsulates ribulose-1,5-bisphosphate carboxylase and carbonic anhydrase. Other well-known BMCs include the Pdu and Eut BMCs, which metabolize 1,2-propanediol and ethanolamine, respectively, with vitamin B12-dependent diol dehydratase enzymes. Recent bioinformatic analyses identified a new prevalent type of BMC, hypothesized to utilize vitamin B12-independent glycyl radical enzymes to metabolize substrates. Here we use genetic and metabolic analyses to undertake in vivo characterization of the newly identified glycyl radical enzyme microcompartment 3 (GRM3) class of microcompartment clusters. Transcriptome sequencing analyses showed that the microcompartment gene cluster in the genome of the purple photosynthetic bacterium Rhodobacter capsulatus was expressed under dark anaerobic respiratory conditions in the presence of 1,2-propanediol. High-performance liquid chromatography and gas chromatography-mass spectrometry analyses showed that enzymes coded by this cluster metabolized 1,2-propanediol into propionaldehyde, propanol, and propionate. Surprisingly, the microcompartment pathway did not protect these cells from toxic propionaldehyde under the conditions used in this study, with buildup of this intermediate contributing to arrest of cell growth. We further show that expression of microcompartment genes is regulated by a two-component system located downstream of the microcompartment cluster.IMPORTANCE BMCs are protein shells that are designed to compartmentalize enzymatic reactions that require either sequestration of a substrate or the sequestration of toxic intermediates. Due to their ability to compartmentalize reactions, BMCs have also become attractive targets for bioengineering novel enzymatic reactions. Despite these useful features, little is known about the biochemistry of newly identified classes of BMCs. In this study, we have undertaken genetic and in vivo metabolic analyses of the newly identified GRM3 gene cluster.
Healthcare Experiences and Needs of Consensually Non-Monogamous People: Results From a Focus Group Study

Abstract Background Individuals engaged in consensual non-monogamy (CNM) face broad and potentially harmful experiences of sexual stigma in society, yet no published empirical literature has examined the experiences of this population within the healthcare system. Aim The present investigation sought to explore positive and negative experiences of CNM individuals within the healthcare system, as well as specific needs of these patients regarding inclusive healthcare practices. Methods 20 CNM-identified adults from a non-profit organization serving CNM individuals completed a brief survey and participated in 1 of 3 focus groups of 70 minutes duration centered on their healthcare needs and experiences. Outcomes CNM patients report challenges in addressing their healthcare needs related to lack of provider knowledge, inadequate preventative screenings, and stigmatizing behaviors that impact their health and trust in the healthcare system. Clinical Implications Healthcare providers must monitor and work to avoid assumptions and pathologization of individuals who engage in CNM, creating an open, accepting environment to work collaboratively with CNM individuals to meet their unique sexual health needs. Strength & Limitations Although the present sample is diverse with respect to sexual and gender identity and socioeconomic status, it may not represent the experiences of CNM individuals outside of the midwestern United States and those who do not identify as polyamorous. Conclusion CNM individuals frequently experience sexual stigma in interactions with the healthcare system that interferes with receipt of sensitive, medically accurate care relevant to their unique needs and experiences. Vaughan MD, Jones P, Taylor BA, et al. Healthcare Experiences and Needs of Consensually Non-Monogamous People: Results From a Focus Group Study. J Sex Med 2019;16:42–51.
Agreement Between Structured Descriptive Assessments and Functional Analyses Conducted Over a Telehealth System

This study examined whether experimental functional analyses (FAs) conducted by parents at home with coaching via telehealth would produce differentiated results, and compared these results to the functions identified from structured descriptive assessments (SDAs) also conducted by parents at home via telehealth. Four boys between the ages of 4- and 8-years old with intellectual and developmental disabilities and their parents participated. All assessments were conducted in the children's homes with their parents serving as intervention agents and with coaching from remote behavior therapists using videoconferencing technology. Parent-implemented FAs produced differentiated results for all 4 children in the study. Overall, analyzing antecedent-behavior (A-B) and behavior-consequence (B-C) relations from the SDA videos identified only half of the functions identified by the FAs. For children whose SDA results were differentiated, analyzing A-B relations correctly identified 4 of 5 functions. Analyzing B-C relations correctly identified 5 of 6 functions identified by the experimental FA, but overidentified attention for all children. Implications for conducting functional analyses and interpreting structured descriptive assessment via telehealth are discussed.
Boron-nitrogen compounds : XXIII The vibrational spectrum of 2-methyl-1,3,2-diazaboracyclohexane

Abstract Major absorptions of the vibrational spectrum of 2-methyl-1,3,2-diazaboracyclohexane have been assigned by utilizing isotopically labeled materials. The spectroscopic data confirm the previously proposed structure of the compound. The nature of the chemical bonding in this boron-nitrogen-carbon heterocycle is discussed briefly.
Antenatally-detected liver cysts: Causes and characteristics, indications for intervention.

Abstract Aim The prevalence of antenatally-detected hepatic cysts is increasing owing to increased use of maternal ultrasonography (USS). Diagnostic precision, however, is challenging and subsequently there is no clear consensus on postnatal management. The aim of the study was to evaluate the natural history and long-term follow up of congenital simple hepatic cysts. Methods Single-center review of prospectively-maintained dataset collected over a 25-year period. Data are quoted as median (range). Results In the period 1991–2016, 31 infants presented with an antenatally-detected cyst which, on postnatal imaging, was likely confirmed as a simple parenchymal hepatic cyst. These together with a further infant who presented at 4 days without any antenatal imaging comprised the study group (n = 32). Gestational age at detection was 23 (13–38) weeks. Maximum antenatal cyst diameter was measured at 19 (4–120) mm. Only the largest required percutaneous aspiration at 35 weeks’ gestation being associated with polyhydramnios. Postnatally, serial USS was performed alongside MRI/CT or liver scintigraphy if there was diagnostic doubt. Initial maximum cyst diameter was 30 (12–120) mm. Five infants came to surgical intervention and this included excision ± marsupialization (n = 4), and a cyst-jejunostomy en Roux in one child thought to have a connection with the biliary tract on intraoperative cholangiography. The mucosal lining in two cysts showed areas of squamous metaplasia, with one more showing an intact squamous lining probably more consistent with an epidermoid cyst. In the remaining cases (n = 27), all asymptomatic, serial USS showed volume maintenance (n = 16) actual volume regression (n = 4) and resolution (n = 7). Median follow-up in these cases was 42 (4–252) months. Conclusion This is the largest case series to date of antenatally-detected simple hepatic cysts. Most can be managed conservatively, and relative regression or resolution is likely. Surgical intervention should be reserved for those: that are large at the outset; show rapid cyst growth — these being typically exophytic in nature; wall irregularity or where there is diagnostic doubt. Type of study Case series. Level of evidence Level IV.
Strontium isotope (87Sr/86Sr) data from archaeological sites in Utah, USA.

Abstract The information presented here includes the results of strontium isotope analysis on 75 baseline samples from nine Fremont sites in Utah. The baseline samples are of lagomorphs and rodents with limited foraging ranges. The baseline ranges for each site were calculated with two standard deviations. Also included are the raw strontium isotopic data for 30 large game samples from Wolf Village, a Fremont site in Utah. Additional data include a map showing the location of the sites in this study, box plots portraying the local ranges of nine Fremont sites in Utah, and an individual value plot comparing the Wolf Village large game samples to the strontium baseline for the site. These data compliment the discussions and interpretations found in “Identifying Strontium Baselines and Large Game Animal Trade at Fremont Sites through Strontium Isotope (87Sr/86Sr) Analysis” [1].
Collaborative Mentoring for Retaining Secondary Biology Teachers.

Veteran biology teachers are at risk of leaving the classroom due to burnout, feeling uninspired, and overall job dissatisfaction. One way to keep veteran teachers engaged is through continued mentoring. Yet current mentoring programs vary in scope, often focus too heavily on one-to-one talk, with mentors serving as therapists, and generally fail to include veteran teachers. Considering this is not how schools operate, we argue active mentoring for veteran teachers is best when embedded into regular school practice. Collaborative mentoring, as we have termed it, pairs experienced high school teachers with other veteran colleagues, including university professors, in professional development activities centering on improving classroom practices. We believe that collaborative mentoring holds potential to meet the needs of all stakeholders—high school students for support in learning laboratory and writing skills; university faculty for hands-on classroom work and reflective practice, as well as for sharing content and pedagogical knowledge with professionals in the field; and, specifically, veteran biology teachers for expanding access to meaningful professional development opportunities. Focusing on applicable classroom pedagogy serves as a cost-effective model for professional development for veteran teachers, possibly increasing job satisfaction and teacher retention in high schools across the nation.
An LSTM based Kalman Filter for Spatio-temporal Ocean Currents Assimilation

In this paper, we present a Long Short-Term Memory (LSTM)-based Kalman Filter for data assimilation of a 2D spatio-temporally varying depth-averaged ocean flow field for underwater glider path planning. The data source to the filter combines both the Eulerian flow map with the Lagrangian mobile sensor data stream. The depth-averaged flow is modeled as two components, the tidal and the non-tidal flow component. The tidal flow is modeled with ADCIRC (Advanced Three-Dimensional Circulation Model), while the non-tidal flow field is modeled by a set of spatial basis functions and their time series coefficients. The spatial basis functions are the principal modes derived by performing EOF (Empirical Orthogonal Functions) analysis on the historical surface flow field measured by high frequency radar (HFR), and the temporal coefficients of the spatial basis function are modeled by an LSTM neural network. The Kalman Filter is performed to combine the dynamics derived from the LSTM network, and the observations from the glider flow estimation data. Simulation results demonstrate that the proposed data assimilation method can give flow field prediction of reasonable accuracy.
Racial and Ethnic Disparities in Treatment and Treatment Type for Depression in a National Sample of Medicaid Recipients.

Objective:The purpose of this secondary data analysis was to describe racial-ethnic disparities in receipt of depression treatment and treatment modality among adult Medicaid beneficiaries with dep...
Mitochondrial carbonic anhydrase VA deficiency in three Indian infants manifesting early metabolic crisis

Abstract Background Hyperammonemia and hyperlactatemia in neonates and young children with non-specific biochemical markers poses a diagnostic challenge. An accurate diagnosis is essential for effective management. Case reports We present three infants from unrelated families, one with infantile and two with neonatal hyperammonemic encephalopathy, hypoglycaemia, and hyperlactatemia. The underlying cause was confirmed following whole exome sequencing as biochemical markers were not conclusive of a definite diagnosis. Conclusion The combination of hyperammonemic encephalopathy, hyperlactatemia and hypoglycemia in neonates and infants should prompt physicians to suspect Carbonic anhydrase VA deficiency. Majority of these children can have a favourable long-term outcome with symptomatic treatment.
Integration of ozone with co-immobilized microalgae-activated sludge bacterial symbiosis for efficient on-site treatment of meat processing wastewater

Abstract Direct discharge of high concentration meat processing wastewater (MPW) into municipal sewage system will cause serious shock loading and reduce wastewater treatment efficiency, thus, efficient on-site pretreatment is usually required. Purpose of this study is to integrate ozone with microalgal biotreatment to achieve effective removal of both organic compounds and nutrients with one-step biodegradation and obtain high quality effluent dischargeable to municipal sewage system. Results showed that ozone pretreatment removed 35.0–90.2% color and inactivated 1.8–4.7 log CFU/mL bacteria in MPW. In post biotreatment using microalgae co-immobilized with activated sludge (ACS) bacteria, bacterial growth in ozone pretreated wastewater (7.1–8.1 log CFU/mL) were higher than non-pretreated control (6.0 log CFU/mL) due to enhanced biodegradability of wastewater pollutants. Algal biomass growth in wastewater pretreated with 0.5 (2489.3 mg/L) and 1 (2582.0 mg/L) minute's ozonation were improved and higher than control (2297.1 mg/L). Ozone pretreatment significantly improved nutrients removal. Following ozone pretreatment of 0.5 min, microalgal biotreatment removed 60.1% soluble chemical oxygen demand (sCOD), 79.5% total nitrogen (TN) and 91.9% total phosphate (PO43−) which were higher than control (34.4% sCOD, 63.4% TN, 77.6% total PO43−). Treated effluent contained 342.3 mg/L sCOD, 28.8 mg/L TN, 9.9 mg/L total PO43− and could be discharged into municipal sewage system. However, excessive ozone pretreatment displayed adverse impact on algal growth and sCOD removal. Therefore, integration of 0.5 min's ozone pretreatment with microalgae-based biotreatment is an efficient on-site treatment to simultaneously remove organic compounds and nutrients with one-step biodegradation.
Sources of Occupational Radiation Exposure

The reactor core is the primary source of the radionuclides encountered at LWR’s whether they are fission products or activation products. Radiation is produced when the fissile nuclides U-235 and later in core life, Pu-239 fission. The fission process produces neutrons, beta particles and gamma radiations directly along with radioactive fission products. Along with the two fission products, two to three neutrons are also emitted in addition to the energy given off during the process. The fission products consist of numerous radionuclides many of which emit beta and gamma radiations. In addition to neutrons posing a direct radiation hazard when the reactor is critical, they also produce radionuclides by means of neutron activation.
Avatars, Scarlet 'A's, and Adultery in the Technological Age

As the law struggles to keep pace with technology, this Article addresses a relatively new and quickly escalating twist on the age-old problem of adultery — namely, online infidelity — and questions whether victim spouses should be allowed to secure a fault-based divorce. The Article surveys the current and predicted future opportunities for online sexual gratification and provides an overview of the history of divorce and adultery and the legal effects of fault-based divorce. It goes on to examine the current law of adultery and questions whether that law should be expanded to include online infidelity. The Article considers the evolution of marriage and infidelity, acknowledging that infidelity and adultery are not interchangeable terms. Thus, after establishing that online infidelity is infidelity, it considers whether this particular form of infidelity should be equated with adultery. Finally, the Article concludes that the definition of adultery should be extended to capture certain forms of online infidelity and offers a proposal for legislators and decision-makers.
IDP - An Interactive Discourse Planner

We are building a system that plans text to describe and justify domain plans interactively. This paper focuses on the second task, plan justification. A speaker uses plan justification to have a listener adopt a recommended plan. The text plan that our system incrementally formulates and executes to justify its recommendation is represented uniformly in the same knowledge base with the domain plans that are under discussion. In this way, the text plan and the domain plans are both accessible for analyzing the listener's feedback. The system can interpret vaguely articulated questions, generate concise replies and metacomments, and detect feedback that initiates digressions. As a testbed for our model, we are implementing a system that gives driving directions and route advice interactively.
Galactic coronae in the intracluster environment: semiconfined stellar-feedback-driven outflows

Recently X-ray observations have shown the regular presence of compact galactic coronae around intermediate-mass spheroid galaxies embedded in the intracluster/intragroup medium (ICM). We conduct 2D hydrodynamic simulations to study the quasi-steady-state properties of such coronae as the natural products of the ongoing distributed stellar feedback semiconfined by the thermal and ram pressures of the ICM. We find that the temperature of a simulated corona depends primarily on the specific energy of the feedback, consistent with the lack of correlation between the observed hot gas temperature and K-band luminosity of galaxies. The simulated coronae typically represent subsonic outflows, chiefly because of the semiconfinement. As a result, the hot gas density increases with the ICM thermal pressure. The ram pressure, on the other hand, mainly affects the size and lopsidedness of the coronae. The density increase could lead to the compression of cool gas clouds, if present, and hence the formation of stars. The increase also enhances radiative cooling of the hot gas, which may fuel central supermassive black holes, explaining the reason that the frequency of active galactic nuclei observed in clusters is higher than that in the field. The radiation enhancement is consistent with a substantially higher surface brightness of the X-ray emission detected from coronae in the cluster environment. The total X-ray luminosity of a corona, however, depends on the relative importance of the surrounding thermal and ram pressures. These environment dependences should at least partly explain the large dispersion in the observed diffuse X-ray luminosities of spheroids with similar stellar properties. Furthermore, we show that an outflow powered by the distributed feedback can naturally produce a positive radial gradient in the hot gas entropy, mimicking a cooling flow.
Reducing the risk of injury from table saw use: the potential benefits and costs of automatic protection

The use of table saws in the United States is associated with approximately 28,000 emergency department (ED) visits and 2,000 cases of finger amputation per year. This article provides a quantitative estimate of the economic benefits of automatic protection systems that could be designed into new table saw products. Benefits are defined as reduced health-care costs, enhanced production at work, and diminished pain and suffering. The present value of the benefits of automatic protection over the life of the table saw are interpreted as the switch-point cost value, the maximum investment in automatic protection that can be justified by benefit-cost comparison. Using two alternative methods for monetizing pain and suffering, the study finds switch-point cost values of $753 and $561 per saw. These point estimates are sensitive to the values of inputs, especially the average cost of injury. The various switch-point cost values are substantially higher than rough estimates of the incremental cost of automatic protection systems. Uncertainties and future research needs are discussed.
Diode-pumped, self-starting additive-pulse mode-locked Nd:YAG and Nd:YLF lasers

Diode-pumped solid-state lasers have been shown to be compact, efficient sources of laser radiation. Active mode-locking of diode-pumped lasers has been achieved using amplitude modulation and pulses as short as 7 ps have been obtained.1-3 Here, we demonstrate that short pulses can be generated in these devices with no need for active modulation by coupling to a nonlinear external cavity. Mode-locked pulses of ~ 1.7 ps in Nd:YAG have been measured; we believe that these are the shortest pulses obtained from a mode-locked Nd3+ laser.
Benchmark dose profiles for joint-action continuous data in quantitative risk assessment

Benchmark analysis is a widely used tool in biomedical and environmental risk assessment. Therein, estimation of minimum exposure levels, called benchmark doses (BMDs), that induce a prespecified benchmark response (BMR) is well understood for the case of an adverse response to a single stimulus. For cases where two agents are studied in tandem, however, the benchmark approach is far less developed. This paper demonstrates how the benchmark modeling paradigm can be expanded from the single-agent setting to joint-action, two-agent studies. Focus is on continuous response outcomes. Extending the single-exposure setting, representations of risk are based on a joint-action dose-response model involving both agents. Based on such a model, the concept of a benchmark profile-a two-dimensional analog of the single-dose BMD at which both agents achieve the specified BMR-is defined for use in quantitative risk characterization and assessment.
Efeito de metais Cobre (Cu) e Zinco (Zn) sobre a comunidade de macroinvertebrados bentônicos em riachos do sul do Brasil - DOI: 10.4025/actascibiolsci.v30i3.677

The aim of this study was to evaluate the effect of metals (Cu and Zn) on the benthic macroinvertebrate community. The organisms and water were collected quarterly between September 2006 and June 2007, in eight sites in streams of two hydrographic basins, influenced by urbanization and agriculture. The values of organism density, taxonomic richness and the Shannon diversity index were calculated. For data evaluation, tests of variance and simple linear regression were used. The results showed variability in the metal concentration and benthic community among seasons and studied streams. Cu showed influence only on Chironomidae density. Zn demonstrated effect on the benthic community and Chironomidae density. None of the metals presented effect on the macroinvertebrate richness and diversity. The results indicate a bioindicator potential of the benthic community in the evaluation of integral quality of the environment.
Elimination of Rubisco alters the regulation of nitrogenase activity and increases hydrogen production in Rhodospirillum rubrum

Nitrogenase not only reduces atmospheric nitrogen to ammonia, but also reduces protons to hydrogen (H2). The nitrogenase system is the primary means of H2 production under photosynthetic and nitrogen-limiting conditions in many photosynthetic bacteria, including Rhodospirillum rubrum. The efficiency of this biological H2 production largely depends on the nitrogenase enzyme and the availability of ATP and electrons in the cell. Previous studies showed that blockage of the CO2 fixation pathway in R. rubrum induced nitrogenase activity even in the presence of ammonium, presumably to remove excess reductant in the cell. We report here the re-characterization of cbbM mutants in R. rubrum to study the effect of Rubisco on H2 production. Our newly constructed cbbM mutants grew poorly in malate medium under anaerobic conditions. However, the introduction of constitutively active NifA (NifA*), the transcriptional activator of the nitrogen fixation (nif) genes, allows cbbM mutants to dissipate the excess reductant through the nitrogenase system and improves their growth. Interestingly, we found that the deletion of cbbM alters the posttranslational regulation of nitrogenase activity, resulting in partially active nitrogenase in the presence of ammonium. The combination of mutations in nifA, draT and cbbM greatly increased H2 production of R. rubrum, especially in the presence of excess of ammonium. Furthermore, these mutants are able to produce H2 over a much longer time frame than the wild type, increasing the potential of these recombinant strains for the biological production of H2.
Particle-Mediated Transport and Fate of a Hydrophobic Organic Contaminant in Southern Lake Michigan: The Role of Major Water Column Particle Species

Abstract A seasonal model of water column abundance and vertical fluxes of major particle species in southern Lake Michigan is developed, based on information obtained through detailed water column sampling and sediment trap deployments. By coupling experimentally-measured equilibrium partition coefficients of a model HOC to the major particle species with the particle model, we predict both particle-specific phase partitioning of the HOC in the water column and fluxes to the sediments over an annual cycle. The results indicate a dynamic seasonal and spatial cycle of HOC association with paniculate material, largely controlled by biological particle production events. Diatoms are the major sorptive particle type for HOCs in the water column during much of the year. Diatoms also serve as the major vector for HOC removal from the water column to the sediments. The fate of contaminants associated with autochthonous particles subject to diagenesis and dissolution near the sediment-water interface is uncertain. Significant phase redistribution of HOCs is likely in the benthic nepheloid layer and the upper few centimeters of sediments.
Report of the working group on triggering and data acquisition

Abstract This paper reports on the discussions of the Trigger and Data Acquisition Working Group at the Beauty '93 workshop held in Liblice, Czech Republic. An
High-pressure combinatorial screening of homogeneous catalysts: hydrogenation of carbon dioxide.

A simple method for high-pressure combinatorial catalyst discovery with visual (dye-based) assay is described. With this method, the first highly active catalyst, incorporating metals outside the platinum group, has been identified for CO2 hydrogenation.
Somatic sensory representation in the thalamic ventrobasal complex of the Virginia opossum.

The present study was designed to investigate the topographic organization of somatic sensory representation in the thalamic ventrobasal complex (Vb) of the Virginia opossum. Tungsten and stainless steel micro electrodes were used to record the electrical activity of single units or single unit clusters in response to mechanical stimulation of the body surface, and the obtained data were used to construct maps of somatic sensory representation in transverse planes of the ventrobasal complex. The general pattern is similar to that found in eutherian mammals. A relatively large contralateral head and face representation is located throughout the entire anterior-posterior extent of the ventrobasal complex, while a relatively smaller representation of contralateral trunk and limbs is located laterally only in the middle regions of the ventrobasal complex. Representations of middorsal head and trunk are located dorsally while those of limb apices are located ventrally. Activity was also recorded in the posterior nuclear region of the thalamus (Po) and in the subthalamic zona incerta (ZI), and there is a suggestion of topographic organization in these nuclear regions as well.
Intracranial pressure monitoring as a guide to prognosis in the nearly drowned, severely comatose child

During a 34-month-period, 55 nearly drowned, comatose children who were admitted to our pediatricintensive care unit were divided into C1 (decorticate), C2 (decerebrate), and C3 (flaccid) subgroups. Patients in subgroup C3 were selected for intracranial pressure (ICP) measurements by the subarachnoid bolt, and were reclassified according to clinical outcome into recovered (group A), fataly (group B), and brain damaged (group C) categories. Six children (29%) had complete recovery, 10 died (48%), and five (23%) demonstrated residual brain damage. There was a highly significant difference between the ICP in group A and group B ( P P P 20 mm Hg and CPP 20 mm Hg, but not both. We find that intracranial pressure monitoring is a safe, useful tool in predicting death or survival, but not residual brain damage, in the nearly drowned, severely comatose child.
A shock tube study of the reaction of the hydroxyl radical with H2, CH4, c-C5H10, and i-C4H10

Reactions of the hydroxyl radical, OH, with several reactants have been studied near 1200 K in shock tube experiments in which UV absorption was used to monitor the OH concentration. The values of the rate coefficients were found to be 2.7 × 1012, 2.6 × 1012, 2.8 × 1013, and 1.26 × 1013 cm3/mol-s for the reactions of OH with hydrogen, methane, cyclopentane, and isobutane, respectively. These measured values are compared with previous experimental results and transition-state theory calculations.
Regulatory cancer risk assessment based on a quick estimate of a benchmark dose derived from the maximum tolerated dose.

The proposed U.S. Environmental Protection Agency carcinogen risk assessment guidelines employ a benchmark dose as a point of departure (POD) for low-dose risk assessment. If information on the carcinogenic mode of action for a chemical supports a nonlinear dose–response curve below the POD, a margin-of-exposure ratio between the POD and anticipated human exposure would be considered. The POD would be divided by uncertainty (safety) factors to arrive at a reference dose that is likely to produce no, or at most negligible, cancer risk for humans. If nonlinearity below the POD is not supported by sufficient evidence, then linear extrapolation from the incidence at the POD to zero would be used for low-dose cancer risk estimation. The carcinogen guidelines suggest that the lower 95% confidence limit on the dose estimated to produce an excess of tumors in 10% of the animals (LTD10) be used for the POD. Due to the relatively narrow range of doses in 2-year rodent bioassays and the limited range of statistically significant tumor incidence rates, the estimate of the LTD10obtained from 2-year bioassays is constrained to a relatively narrow range of values. Because of this constraint, a simple, quick, and relatively precise determination of the LTD10can be obtained by the maximum tolerated dose (MTD) divided by 7. All that is needed is a 90-day study to establish the MTD. It is shown that the LTD10determined by this relatively easy procedure is generally within a factor of 10 of the LTD10that would be estimated using tumor incidence rates from 2-year bioassays. Estimates of cancer potency from replicated 2-year bioassays, and hence estimates of cancer risk, have been show to vary by a factor of 4 around a median value. Thus, there may be little gain in precision of cancer risk estimates derived from a 2-year bioassay, compared to the estimate based on the MTD from a 90-day study. If the anticipated human exposure were estimated to be small relative to the MTD/7 = LTD10, there may be little value in conducting a chronic 2-year study in rodents because the estimate of cancer risk would be low regardless of the results of a 2-year bioassay. Linear extrapolation to a risk of less than 1 in 100,000 and use of an uncertainty factor, e.g., of 10,000, would give the same regulatory “safe dose.” Linear extrapolation to a virtually safe dose associated with a cancer risk estimate of less than one in a million would be 10 times lower than the reference dose based on the LTD10/10,000.
Transport and magnetic properties of icosahedral and glassy Pd-U-Si alloys.

The glassy phase of ${\mathrm{Pd}}_{58.8}$${\mathrm{U}}_{20.6}$${\mathrm{Si}}_{20.6}$ alloys can be transformed into an icosahedral quasicrystalline phase by thermal annealing. Electrical transport properties of samples undergoing different degrees of glassy-to-icosahedral phase transformation have been measured. The icosahedral phase has an electrical resistivity of \ensuremath{\sim}220 \ensuremath{\mu}\ensuremath{\Omega} cm at room temperature and a negative temperature coefficient of resistivity. The short electronic mean free path is discussed. At low temperature, the negative magnetoresistivity is attributed to magnetic scattering effects. The low-field ac susceptibility as a function of temperature exhibits a spin-glass-type transition which is not suppressed by a dc magnetic field.
The Use of Synchronous Computer Networks in Second Language Instruction: A Preliminary Report

ABSTRACT This paper reports some personal observations regarding a second language teaching situation where non-native speakers of Portuguese participated in class discussions via real time computer networks. Synchronous computer networks have been utilized in university courses to improve group participation in writing and composition in L1 situations. This same process offers L2 an opportunity to participate in interlanguage discussions via computer. Preliminary observations from this experience suggest that computer assisted class discussions may promote increased participation from all members of a work group, allow students to speak without interruption, reduce anxiety which is frequently present in oral conversations, render honest and candid expression of emotion, provide personalized identification of target language errors and create substantial interlanguage communication among L2 learners.
A monotone operator method for the solution of Fredholm integral equations

We consider the approximation of the solutions of the integral equations of the form $$\lambda x(s) = \int\limits_a^b {K(s,t,x(t))dt + y(s)} ,a \leqq s \leqq b,$$ or of the form $$x(s) = \int\limits_a^b {K(s,t)f(t,x(t))dt + y(s)} ,a \leqq s \leqq b$$ by using the techniques of monotone operators.
Who Watches Over a Teacher? On Knowing and Honoring a Teacher and Her Third Listener

This article introduces a teacher as a being of relations—both internal and external—by exploring the nature of a figure of the internal plane that accompanies a teacher in her pedagogical adventure. This figure is a superaddressee, 1 a third listener, who, as the author argues, should be expected to enter a classroom together with a teacher. A superaddressee plays at least two roles. First, it serves as a shortcut to a meaningful relationship and, in this role, takes care of a teacher's need to be known, as well as helps further dialogic relationships. Second, it offers a loophole from imperfect understanding and, in this role, addresses a teacher's need for noncoincidence and protection, as well as protects a pedagogical relationship from a proverbial dead end. It is argued that one of the ways for students to honor their teacher as a being of relations is to know and honor his or her superaddressee(s). In turn, a teacher is responsible for honoring her own superaddressees. In the end, both a teacher an...
Structure and solution of the massive Thirring model

The Hamiltonian of the massive Thirring model is explicitly diagonalized by formulating a Bethe ansatz for the eigenstates. The physical states are described by many-body wave functions representing the vacuum as a filled Fermi-Dirac sea and particle states as excitations built upon it. The spectrum of states is determined by imposing periodic boundary conditions on the wave functions. The energies are calculated by reducing the periodic boundary conditions to linear integral equations. For fermion-antifermion bound states the Dashen-Hasslacher-Neven spectrum is obtained. It is shown that the solution to the massive Thirring model can be understood as the critical limit of Baxter's solution of the eight-vertex model.
Long‐term patterns in growth of Oneida Lake walleye: a multivariate and stage‐explicit approach for applying the von Bertalanffy growth function

Total length (L T ) and its inter annual variation of walleye Sander vitreus from Oneida Lake, New York, based on 51 years (1950-2000) of data for ages 1 to 7 years were analysed. Growth increased over time at young ages, did not change at intermediate ages and decreased at old ages. Total length at age increased over time to age 4 or 5 years, but was stable at older ages. Principle component analysis was used to study the pattern of variations in annual L T increments among years. More than 92 and 91% of inter annual variability in growth was described by the first three principal components for males and females, respectively. The first principal component was a general indicator of annual growth at all ages, but was dominated by annual growth at intermediate ages. The second and third principal components represented contrasts among yearling L T , yearling growth and growth at older ages. Therefore, changes in the three stage-specific parameters. yearling L T , yearling growth and asymptotic L T , explained most of the variance in observed growth. Using these three stage-specific parameters for the von Bertalanffy growth function facilitated interpretations of growth comparisons.
Intracytoplasmic gene delivery for in vitro transfection with cytoskeleton-specific immunoliposomes.

Abstract A novel and highly efficient method of in vitro gene transfection has been developed. This method employs direct intracytoplasmic gene delivery into embryonic cardiocytes using neutral cytoskeletal-antigen specific immunoliposomes (CSIL). These immunoliposomes target cardiocytes specifically under reversible hypoxic conditions. Two independent reporter genes, pGL2 and pSV-β-galactosidase, were used to verify CSIL-transfection (CSIL-fection). The efficiency of CSIL-fection with firefly luciferase pGL2 vector was 30+ times greater than controls consisting of hypoxic cardiocytes treated with plain liposomes (PL) or normoxic cardiocytes treated with CSIL, PL or naked DNA. CSIL-fection was also compared to cationic liposome transfection. Net cationic liposome transfection appeared to be more efficient than CSIL-fection for pGL2 vectors. However, a smaller number of viable cells was observed in the cationic liposome treated cultures than in the CSIL treated cultures. Therefore, to determine whether more cells were transfected with cationic liposomes or CSIL, pSV-β-galactosidase vector was used. CSIL-fection with pSV-β-galactosidase vector produced at least 40 times more transfected cells than those transfected with cationic liposomes. No transfection with pSV-β-galactosidase vectors was obtained with IgG-liposome, PL or naked DNA treatments. Targeted enhanced efficiency of transfection by this novel method could have practical therapeutic applications in the genetic modification of cells ex vivo that could then be reimplanted into patients for gene therapy.
COHERENCE THEORY OF THE ELECTROMAGNETIC FIELD

Up to now the degree of coherence of a wave field was only defined on the basis of a scalar wave theory. In the present paper a generalization is proposed applicable to any quasi-monochromatic stationary electromagnetic field. This « electromagnetic degree of coherence », which is a single scalar quantity, is introduced from the analysis of an interference experiment and it is shown to be related to the trace of the correlation tensor of the electric field introduced byE. Wolf in 1954.
Effect of chlorpromazine and amytal on the reduction of glutathione

Abstract The effects of some compounds, which affect the activity of the central nervous system, on the reduction of glutathione by guinea pig brain preparations were investigated. Chlorpromazine showed the greatest effect by increasing the amount of glutathione reduced by about 2-fold at a concentration of 3 m M . d -Amphetamine also stimulated the reduction but was less effective than chlorpromazine. On the other hand, amytal inhibited the reduction of glutathione. Librium, phenobarbital, serotonin, 1-epinephrine, and 1-norepinephrine had no appreciable effects.
A simplification of combinatory logic

The usual formulations of combinatory logic, as in Church [1] or Curry and Feys [2], have no straightforward semantics. This lack complicates the proofs of basic metasystematic results, prevents the perspicuous formalization of combinatory logic as a deductive theory, and makes the combinators unnecessarily difficult to apply to recursion theory or to the foundations of mathematics. In the present paper we shall give a new formulation of combinatory logic, thought of as an abstract theory of rules. At each stage in the development we shall give a precise semantic interpretation for our axioms. We begin with an abstract treatment of the syntax and semantics of a theory of rules. We then specialize to the theory of the combinators and prove a completeness theorem connecting our axioms with our semantics. On this basis we treat functional abstraction, truth-functions, and the representation of partial recursive functions. In the spirit of Church [1, pp. 62–71], we conclude by extending our methods to the treatment of intensional identity. The theories developed here are part of a simplification of the theory of constructions described in [3]. Their semantics are motivated by the intended interpretation of the theory of constructions. The present paper is selfcontained and can be read without any familiarity with the theory of constructions, although the motivation of several of the notions considered here is given in [3]. In a future publication we will use the results of the present paper as the basis for a detailed study of a simplified form of the theory in [3].
Image-guided macular laser therapy: design considerations and progress toward implementation

Laser therapy is currently the only treatment of proven benefit for exudative age related macular degeneration and diabetic retinopathy. To guide treatment for macular diseases, investigations were initiated to permit overlay of previously-stored angiographic images and image sequences superimposed onto the real-time biomicroscopic fundus image. Prior to treatment, a set of partially overlapping fundus images is acquired and montaged in order to provide a map for subsequent tracking operations. A binocular slit-lamp biomicroscope interfaced to a CCD camera, framegrabber board, and PC permits acquisition and rendering of retinal images. Computer-vision algorithms facilitate robust tracking, registration, and nearvideo-rate image overlay of previously-stored retinal photographic and angiographic images onto the real-time fundus image. Laser treatment is guided in this augmented reality environment where the borders of the treatment target--for example, the boundaries of a choroidal neovascularization complex---are easily identified through overlay of angiographic information superimposed on, and registered with, the real-time fundus image. During periods of misregistration as judged by the amplitude of the tracking similarity metric, laser function is disabled, affording additional safety. Image-guided macular laser therapy should facilitate accurate targeting of treatable lesions and less unintentional retinal injury when compared with standard techniques.
Simulating high-DOF human-like agents using hierarchical feedback planner

We present a multi-agent simulation algorithm to compute the trajectories and full-body motion of human-like agents. Our formulation uses a coupled approach that combines 2D collision-free navigation with high-DOF human motion simulation using a behavioral finite state machine. In order to generate plausible pedestrian motion, we use a closed-loop hierarchical planner that satisfies dynamic stability, biomechanical, and kinematic constraints, and is tightly integrated with multi-agent navigation. Furthermore, we use motion capture data to generate natural looking human motion. The overall system is able to generate plausible motion with upper and lower body movements and avoid collisions with other human-like agents. We highlight its performance in indoor and outdoor scenarios with tens of human-like agents.
What does it mean to blow the whistle

Whistle blowing causes people to pay attention. An alarm has been sounded drawing attention to a particular set of circumstances. When nurses blow the whistle because of unethical or incompetent colleagues, they are going public with this information. Yet, even though nurses are able to provide an ethical justification for the action, not all will look favorably on what has been done. This article examines the concept of whistle blowing, its relationship to advocacy, and some consequences of whistle blowing. This article provides recommendations for educators, health care agencies, and nurses as ways to support nurses who choose to blow the whistle.
Impact of Local Molecular Environment on the Decay of Image Potential States

Image potential-derived states of upright chemisorbed benzoate molecules on a Cu(110) surface have been measured with scanning tunneling spectroscopy. The widths of image-derived features for these adsorbates are sensitive to the presence of coexisting flat-lying benzoate molecules. This dependence is attributed to the different couplings between image potential state wave functions and bulk metal states that result from differences in substrate-mediated intermolecular interactions. The comparative trends are semiquantitatively modeled using a dielectric continuum approach.
In Sickness and in Health: Same-Sex Marriage Bans and Sexually Transmitted Infections

This paper analyzes the relationship between same-sex marriage bans and sexually transmitted infections using state-level data from 1981 to 2008. We hypothesize that same-sex marriage bans may directly affect homosexual behavior; may affect or mirror social attitudes toward gays, which in turn may affect homosexual behavior; and may affect or mirror attitudes toward nonmarital sex, which may affect risky heterosexual behavior. Our findings may be summarized as follows. First, same-sex marriage bans are unrelated to gonorrhea rates, which are a proxy for risky heterosexual behavior. However, they are positively associated with syphilis rates, which are a proxy for risky homosexual behavior. Second, of the different legal measures, bans on both same-sex marriage and civil union are most strongly associated with syphilis. Third, the estimates are smaller when we exclude California, the state with the largest gay population, which may indicate it is indeed the behavior of gay men that is driving the findings.