cssi/SciSciGPT-SciSciNet huggingface dataset:
On the Markoffian approximation in the description of relaxation in open systems.

Most traditional discussions of the Markoffian Born approximation of relaxation phenomena (e.g., Bloch equations) are based on the assumption of widely separated time scales in the non-Markoffian weak coupling generalized master equation. By exploiting the physically reasonable Gaussian factorization property of multitime correlation functions which enter through the system reservoir interaction, recent work has shed significant new light on the relationship between the Markoffian-Born approximation and the exact generalized master equation (GME) describing the evolution of the relaxing subsystem. Two limits for which the GME becomes the Born approximation relaxation equation arc discussed: (1) the Van Hove (λ2t) limit rigorously discussed for open systems by Davies, (2) the zero memory (white noise) suggested by Middleton—Schieve and recently discussed for open systems by Gorini—Kossakawsky and Palmer. We have outlined the proof of this limit. We then discuss the physical meaning of these two exact limits in the context of the general theory of kinetic equations of Resibois. The dominant pole contributions are isolated to all orders by means of an expansion in which the terms are in norm proportional to powers of the ratio of the time scales τc/τB where τc is the two point correlation memory time and τB the relaxation time in the Born approximation. Each of the above exact limits corresponds to the vanishing of this ratio. Comments are made on nonexponential decay.
Comparative toxicities of putative phagocyte-generated oxidizing radicals toward a bacterium (Escherichia coli) and a yeast (Saccharomyces cerevisiae).

Abstract Toxicities of the radiolytically generated oxidizing radicals HO , CO3 −a, and NO2 toward suspension cultures of a bacterium (Escherichia coli) and a yeast (Saccharomyces cerevisiae) were examined. As demonstrated by the absence of protection from the membrane-impermeable HO scavenger polyethylene glycol (PEG), externally generated HO was not bactericidal under these conditions; however, partial protection by PEG was observed for S. cerevisiae, indicating the presence of a fungicidal pathway involving external HO . For both organisms, conversion of external HO to the secondary radical, CO3 −, by reaction with HCO3− increases their susceptibility to radiolytic killing. In contrast, externally generated NO2 exhibited toxicity comparable to that of CO3 − toward E. coli, but completely blocked the extracellular toxicity of HO toward S. cerevisiae. Cogeneration of equal fluxes of NO2 − and either HO or CO3 − also essentially eliminated the extracellular microbicidal reactions. This behavior is consistent with expectations based upon relative rates of radical–radical self-coupling and cross-coupling reactions. The different patterns of toxicity observed imply fundamentally different microbicidal mechanisms for the two organisms, wherein the bacterium is susceptible to killing by oxidation of highly reactive targets on its cellular envelope but, despite undergoing similar oxidative insult, the fungus is not.
SU-E-CAMPUS-J-05: Quantitative Investigation of Random and Systematic Uncertainties From Hardware and Software Components in the Frameless 6DBrainLAB ExacTrac System

Purpose: To evaluate setup accuracy and quantify individual systematic and random errors for the various hardware and software components of the frameless 6D-BrainLAB ExacTrac system. Methods: 35 patients with cranial lesions, some with multiple isocenters (50 total lesions treated in 1, 3, 5 fractions), were investigated. All patients were simulated with a rigid head-and-neck mask and the BrainLAB localizer. CT images were transferred to the IPLAN treatment planning system where optimized plans were generated using stereotactic reference frame based on the localizer. The patients were setup initially with infrared (IR) positioning ExacTrac system. Stereoscopic X-ray images (XC: X-ray Correction) were registered to their corresponding digitally-reconstructed-radiographs, based on bony anatomy matching, to calculate 6D-translational and rotational (Lateral, Longitudinal, Vertical, Pitch, Roll, Yaw) shifts. XC combines systematic errors of the mask, localizer, image registration, frame, and IR. If shifts were below tolerance (0.7 mm translational and 1 degree rotational), treatment was initiated; otherwise corrections were applied and additional X-rays were acquired to verify patient position (XV: X-ray Verification). Statistical analysis was used to extract systematic and random errors of the different components of the 6D-ExacTrac system and evaluate the cumulative setup accuracy. Results: Mask systematic errors (translational; rotational) were the largest and varied from one patient to another in the range (−15 to 4mm; −2.5 to 2.5degree) obtained from mean of XC for each patient. Setup uncertainty in IR positioning (0.97,2.47,1.62mm;0.65,0.84,0.96degree) was extracted from standard-deviation of XC. Combined systematic errors of the frame and localizer (0.32,−0.42,−1.21mm; −0.27,0.34,0.26degree) was extracted from mean of means of XC distributions. Final patient setup uncertainty was obtained from the standard deviations of XV (0.57,0.77,0.67mm,0.39,0.35,0.30degree). Conclusion: Statistical analysis was used to calculate cumulative and individual systematic errors from the different hardware and software components of the 6D-ExacTrac-system. Patients were treated with cumulative errors (<1mm,<1degree) with XV image guidance.
The effect of titanium on Al Ti contacts to p-type 4H-SiC

Abstract The influence of composition on the electrical characteristics of Al–Ti ohmic contacts to p-type 4H-SiC was investigated. On SiC with NA=4.8×1018 cm−3, the lowest specific contact resistance obtained was 2.5×10−4 Ω cm2. It was found, however, that the titanium concentration had little effect on the electrical properties of the contacts, with specific contact resistance varying by only a factor of four over a range of concentrations from 0 to 50 wt.%. Additional analytical data were obtained by scanning electron microscope and atomic force microscope observations. It was found that Al–Ti contacts with 31 wt.% Ti resulted in a pit density of approximately 20 pits/100 μm2 with an average depth of 283 A and a maximum depth of 477 A. Pure Al contacts had a lower pit density of approximately 8–10 pits/100 μm2, but the pits were larger and deeper, with an average depth of 358 A and a maximum depth of 510 A. Raised areas of unknown composition and origin were also observed. It is likely that both of these types of features contribute to the ohmic behavior of the contact after annealing, but an exact mechanistic description remains to be identified.
Electromagnetic Response of an Electrically Small Bianisotropic Ellipsoid Immersed in a Chiral Fluid

The electromagnetic response of a homogeneous, electrically small ellipsoid made of a general linear bianisotropic material immersed in a chiral fluid has been obtained.
Inter-comparison study of water level estimates derived from hydrodynamic–hydrologic model and satellite altimetry for a complex deltaic environment

Abstract Riverine deltas are hydrologically one of the most active terrestrial bodies supporting an intricate network of rivers, a highly unsteady flow regime, high agricultural productivity and large population centers. Understanding the complex hydrology of riverine deltas is challenging due to the paucity of conventional ground-based measurements on river water levels and flows that result in large spatial and temporal sampling gaps. One way to bridge this sampling issue is to employ hydrodynamic models in combination with remotely-sensed water level elevation data from satellite altimetry in a data assimilation framework. However, a good understanding of the performance of models and altimetry is required beforehand. Using Bangladesh as an example of a complex delta, an inter-comparison study was therefore performed for water level estimates derived from the two methods: 1) satellite altimetry and 2) hydrodynamic–hydrologic modeling framework. The Envisat mission was selected for satellite altimetry-based water level data. For the modeling framework, a calibrated 1-D hydrodynamic model, HEC-RAS, was set up for the major rivers of Bangladesh using in-situ river bathymetry, gaged stream flow and water level data. Envisat water level estimates were generally found to be exceeded by the model-based values by 0.20 m and 1.90 m for Monsoon and dry seasons, respectively. In general, the average RMSE between Envisat and modeled estimates is more than 2.0 m. The closest agreement with altimetry was observed during the high flow Monsoon season over the Brahmaputra river. Envisat estimates are found to disagree most with model-based estimates for small to medium-sized river basins that are mountainous and flashy. This inter-comparison study provides preliminary guidance on the relative weights to assign for each type of estimate when designing a data assimilation scheme for optimal water level prediction in ungaged basins.
Regional long-term climate change (1950–2000) in the midtropical Atlantic and its impacts on the hydrological cycle of Puerto Rico

[1] Large-scale climate data for the north tropical Atlantic (NTA) region show that air temperatures have increased during the past 50 years (1955–1959 to 2000–2004) with moderate warming near the Caribbean islands to considerable heating in the northern region. This pattern may be driven by sea surface temperature anomalies in the same region of study that follow relatively small changes in the Caribbean basin to stronger anomalies in the northeast. These changes might be associated with changes in the long-term pattern of the NTA high-pressure system that drives climate in the region. A series of mesoscale numerical experiments were designed to study the regional impacts these large-scale changes have on the hydrological cycle of the island of Puerto Rico. Results indicate that increased easterly surface winds for the 1950–2000 time frame disrupts a pattern of inland moisture advection and convergence zone, increasing cloud base heights and reducing the total column liquid water content over high elevations. This combination of factors produces a reduction in precipitation over the central and eastern mountains of Puerto Rico.
Process development for hydrothermal liquefaction of algae feedstocks in a continuous-flow reactor

Abstract Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL). High levels of carbon conversion to gravity separable biocrude product were accomplished at relatively low temperature (350 °C) in a continuous-flow, pressurized (sub-critical liquid water) environment (20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt.% of dry solids. Catalytic hydrotreating was effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic contamination in the byproduct water. All three process steps were accomplished in bench-scale, continuous-flow reactor systems such that design data for process scale-up was generated.
Instruction dependent activation during optokinetic nystagmus (OKN) stimulation: An FMRI study at 3 T

Abstract Modifying experimental conditions of optokinetic nystagmus (OKN) result in different outcomes and may not optimally translate into clinical testing. The purpose of this study was to assess the influence of subject instruction on the anatomical correlates of OKN. The instructions were to voluntarily look or stare at the same moving grating with fixed contrast and spatial and temporal frequencies. Look and stare OKN were generated under identical stimulus “ON” conditions (vertical sine wave grating of 1.14 c/deg drifting right to left at 11.4 c/s with binocular viewing). FMRI was undertaken utilizing a 3.0 T GE system and the BOLD technique. Subjects included 6 normal adults ranging in age from 18 to 54 years with normal visual acuity (20/20 or better) and normal stereoacuity (40 s of arc or better). The results reveal that look OKN generated significantly more cortical FMRI activation than stare OKN. Look OKN areas included the culmen, parahippocampal, lingual, middle temporal gyri, inferior and superior parietal lobules and precuneus, all of which were unilaterally activated in the left hemisphere. The middle occipital gyrus was unilaterally activated in the right hemisphere while the cuneus was bilaterally activated. These results show that the activation sites for OKN studies are dependent on subject instruction which influence the type of OKN generated. Specifically, voluntary look OKN involved more brain sites than stare OKN. In so doing, we illustrate the importance of subject instruction and recommend that FMRI investigators of OKN be cognizant of these effects. The anatomical correlates of the look versus stare are discussed.
Tailoring nicotine replacement therapy: rationale and potential approaches.

Nicotine replacement therapy (NRT) is an effective treatment for smoking cessation, but as with all such pharmacotherapies, the majority of smokers who use NRT products do not stop smoking or remain abstinent long term. Treatment outcome is affected by a range of individual-specific factors, as well as the pharmacokinetic profile of each NRT formulation. This has led to speculation that abstinence rates could be improved if NRT treatments were individually tailored to best match each individual’s needs and preferences. There are also populations for whom special product and dosage considerations are warranted to maximise treatment safety. This paper reviews the rationale for NRT treatment, standard dose recommendations and recommendations for how to best match NRT treatment to the specific needs of individual smokers. We also review emerging evidence that genetic profiling may one day be a useful consideration for tailoring NRT treatment.
Simulation Study of Wind Power with Continuously Variable Transmission

Working principle of continuously variable transmission (CVT) applying in wind power system is analyzed. Mathematic model of CVT in wind power is established. Compared with fixed pitch wind power, the relation between wind energy utilization coefficient, power and wind speed are studied. Dynamic simulations of CVT wind power system are researched in random wind speeds. The CVT transmission ratio, wind turbine rotational speed, wind energy utilization coefficient, generator's rotational speed, wind turbine power and generator power are simulated when wind speed signals are random changed. Simulation results show that wind power applying CVT makes wind turbine operate at an optimal blade tip ratio, obtain an optimal wind energy utilizing coefficient, take full advantage of wind energy and be superior to fixed pitch wind power. Generator outputs constant frequency voltage and smoothly variable powers without applying other electric power and electronic equipments.
Effects of carrier screening on the average electric field in a GaAs-based p-i-n nanostructure under subpicosecond laser excitation

We have used electric-field-induced Raman scattering to quantitatively assess the effects of carrier screening on the average electric fields in a GaAs-based p-i-n nanostructure semiconductor under the subpicosecond laser photoexcitation. Our experimental results demonstrated that the effects of carrier screening on the average electric field were negligible for photoexcited electron-hole pair density of n less than or equal to 10 15 cm -3 . As the density of photoexcited carriers increased we observed a significant decrease of the average electric field. In particular, for n equals 10 18 cm -3 , a decrease of electric field of about 50% was found. All of these experimental results were explained by ensemble Monte Carlo simulations and very good agreement has been obtained.
Surface chemical control of mechanical energy losses in micromachined silicon structures

Mechanical energy dissipation in room-temperature micromechanical silicon torsional resonators, with resonant frequencies ranging from 2.2 to 23 MHz, is considerably increased when a single monolayer of hydrogen atoms is replaced by 13 A of silicon oxide (which corresponds to the oxidation of less than 2 silicon bilayers.) Measurements of oxidation-induced resonant frequency shifts show that increased dissipation cannot be attributed to chemically induced changes in the stress or tension of the resonator. The dependence of both the frequency shift and reduction in quality factor on resonator size are consistent with a chemically induced surface loss mechanism. Quantitative analysis shows that even relatively unstressed areas of the surface can contribute considerably to mechanical energy dissipation. The scaling of losses with resonator dimensions suggests that surface effects will become increasingly more important as the sizes of micromechanical devices continue to decrease.
Domestic Violence Between Same-Gender Partners Recent Findings and Future Research

Empirical literature about same-gender domestic violence was relatively nonexistent until the past 20 years, and conducting research with this population about a sensitive topic remains a daunting endeavor. Existing studies reveal similarities between opposite-and same-gender domestic violence in prevalence, types of abuse, and various dynamics, as well as dispel myths and establish a theoretical basis on which to conduct future research. Differences are evident in areas such as help-seeking behaviors and correlates, thus demanding unique assessment and intervention strategies. This article presents further explanation of the latest research, recommendations for future studies, and effective as well as problematic methodological practices about same-gender domestic violence.
Bacterial infections of the skin

Abstract Bacterial infections of the skin comprise a significant proportion of the disorders seen in the practice of dermatology. Many of these disorders represent primary infections, that is, the infection occurs at the site of cutaneous inoculation of bacteria. Common primary bacterial infections of the skin due to gram-positive and gram-negative bacteria include impetigo, ecthyma, cellulitis, erysipelas, folliculitis, furunculosis, carbuncles, erythrasma, pitted keratolysis, and Pseudomonas toe web infection. Less common infections include blistering distal dactylitis, necrotizing fasciitis, botryomycosis, blastomycosis-like pyoderma, trichomycosis axillaris, erysipeloid, ecthyma gangrenosum, rhinoscleroma, and infections due to Pasteurella multocida and Vibrio vulnifcus . Several new antimicrobial agents may be effective in the treatment of cutaneous bacterial infections. These antibiotics include cefprozil, an oral second-generation cephalosporin; cefpodoxime proxetil, an oral thirdgeneration cephalosporin; loracarbef, an oral carbacephem; clarithromycin and azithromycin, which are oral macrolide antibiotics; and ciprofloxacin and ofloxacin, which are fluoroquinolones.
Development of synthetic salinity from remote sensing for the Columbia River plume

[1] The Columbia River plume (CRP) is an ecologically important source of nutrients, pollutants, and fresh water to the Oregon/Washington shelf. It is traditionally under-sampled, with observations constrained to ships or moorings. High-spatial- and temporal-resolution observations afforded by satellites would increase sampling if the plume could be quantitatively detected in the imagery. Two empirical algorithms are presented using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate sea surface salinity in the region of CRP. Salinity cannot be detected directly, so a proxy for fresh water is employed. Light absorption by chromophoric dissolved organic matter (aCDOM) is inversely proportional to salinity and linear because of conservative mixing of CDOM-rich terrestrial runoff with surrounding ocean water. To estimate synthetic salinity, simple linear (salinity versus aCDOM) and multiple linear (salinity and temperature versus aCDOM) algorithms were developed from in situ measurements of aCDOM collected on the Coastal Ocean Processes–River Influences on Shelf Ecosystems cruises. These algorithms were applied to MODIS 250 m resolution data layers of sea surface temperature and absorption by colored dissolved and detrital matter (aCDM) estimated at 350 nm and 412 nm from the Garver-Siegel-Maritorena model version 1 algorithm. Validation of MODIS-derived synthetic salinity with coincident in situ measurements revealed significant correlation during both downwelling (simple, β1 = 0.95 and r2 = 0.89; multiple, β1 = 0.92 and r2 = 0.89) and upwelling periods (simple, β1 = 1.26 and r2 = 0.85; multiple, β1 = 1.10 and r2 = 0.87) using the 412 nm data layer. Synthetic salinity estimated using the 350 nm data layer consistently overestimated salinity. These algorithms, when applied to aCDM at 412 nm, enable synoptic observations of CRP not permitted by ships or moorings alone.
Atlavasc: an interactive vascular atlas

Learning Objectives Our goal is to review the vascular anatomy with correlative imaging between multiple imaging modalities. Background A solid understanding of complex vascular anatomy is essential for the developing interventional radiologist. Many other specialties also use vascular imaging following trauma, infection, infarction, vasculitis or even pre-operative planning or post-operative follow-up. At the present time, there are only a few available vascular atlases and very limited interactive or online resources available to study and review vascular anatomy. Clinical Findings/Procedure Details The online interactive vascular atlas will highlight the extremity vasculature with various cases illustrating vessel anatomy. Conclusion and/or Teaching Points This module will allow any interested users to review anatomy by interactive scrolling through extremity vasculature in multiple planes with labeled static images which highlight pertinent anatomy. The user will also be able to self-quiz at the end of the module to assess knowledge of vascular anatomy.
Composite nanoparticles: the best of two worlds

Nanomaterials have rapidly moved into the mainstream for chemical and biological analysis. Nanoparticle probes enhance signal intensity, increase the chemical and physical stability of the probe, and facilitate surface modification for specific targeting. Unfortunately, common problems are encountered with many nanoparticle probes, e.g., poor solubility, poor biocompatibility, and leakage of encapsulated components, that severely restrict the application of probes to ex vivo samples under carefully controlled conditions. A wide range of recently developed multifunctional nanomaterials are poised to make significant contributions to molecular analysis of biological systems. Composite nanoparticle geometries, including composites, hybrids, and core-shell nanoparticles prepared using two or more materials, e.g., silica/inorganic, silica/polymer, or polymer/inorganic combinations, offer improved solubility, easier functionalization, and decreased toxicity compared with the related single-component materials. Furthermore, composite nanomaterials present substantial signal amplification, and improved multiplexing for higher-sensitivity and higher-resolution measurements. Further development and integration of composite nanomaterials into the quantitative sciences will play a key role in the future of functional probes for imaging, quantitative analysis, and biological manipulation.
Failure of corticosteroid therapy for experimental acid aspiration.

Early death after acid aspiration results from hypoxia and hypovolemic shock. Pharmacologic doses of methylprednisolone sodium succinate (CS) are alleged to be beneficial in the early therapy of aspiration. Aspiration pneumonia was simulated in 27 mongrel dogs. Hydrochloric acid 0.1 N (pH ≤ 1) was instilled intratracheally (1.0 ml/kg). Controls (N = 7) received acid alone. Group 1 dogs (N = 10) received acid followed 5 min later by methylprednisolone sodium succinate (CS) (30 ml/kg iv). Group 2 (N = 10) received CS 20 min before aspiration. Femoral artery and pulmonary artery catheters were inserted for pressure and cardiac output monitoring and for blood sampling. Dogs received saline solution (4 ml/kg/hr iv) for the 6 hr of the experiment. Systemic and pulmonary arterial and wedge pressures were monitored and cardiac index (CI) was calculated. Intrapulmonary shunt (QsQt) was calculated with Berggren's equation. Lung water as a percentage of lung weight (%LW) was calculated for excised lungs. Baseline and 6-h values were tabulated. Depression of CI and increased QsQt were observed in controls. Treated animals maintained CI but shunting was not improved. Increased %LW indicated pulmonary edema in all animals. Even when given before acid aspiration, CS failed to control shunting and edema.
Ion Regulation in the Brain: Implications for Pathophysiology

Ions in the brain are regulated independently from plasma levels by active transport across choroid plexus epithelium and cerebral capillary endothelium, assisted by astrocytes. In "resting" brain tissue, extracellular potassium ([K+]o) is lower and [H]o is higher (i.e., pHo is lower) than elsewhere in the body. This difference probably helps to maintain the stability of cerebral function because both high [K]o and low [H+]o enhance neuron excitability. Decrease in osmolarity enhances synaptic transmission and neuronal excitability whereas increased osmolarity has the opposite effect. Iso-osmotic low Na+ concentration also enhances voltage-dependent Ca2+ currents and synaptic transmission. Hypertonicity is the main cause of diabetic coma. In normally functioning brain tissue, the fluctuations in ion levels are limited, but intense neuronal excitation causes [K+]o to rise and [Na+]o, [Ca2+]o to fall. When excessive excitation, defective inhibition, energy failure, mechanical trauma, or blood-brain barrier defects drive ion levels beyond normal limits, positive feedback can develop as abnormal ion distributions influence neuron function, which in turn aggravates ion maldistribution. Computer simulation confirmed that elevation of [K+]o can lead to such a vicious circle and ignite seizures, spreading depression (SD), or hypoxic SD-like depolarization (anoxic depolarization).
Antibiotics for Reduction of Posttonsillectomy Morbidity: A Meta‐Analysis

Objective: To reconcile conflicting published reports regarding the clinical efficacy of postoperative antibiotics for reduction of posttonsillectomy morbidity. Study Design: Systematic review (meta-analysis). Methods: Meta-analysis of seven randomized controlled trials of postoperative oral antibiotics in patients undergoing tonsillectomy or adenotonsillectomy. Postoperative pain and time to return to normal activity and diet were studied as distinct end points using a random effects model with weighted mean difference (RevMan 4.2). Search strategy included electronic searches of PubMed and Cochrane library databases; cross-referencing textbooks, reviews, and original trials; and contacting experts in the field. Results: Subjects treated with antibiotics experienced an earlier return to a normal diet (-1.22 days; 95% confidence interval [CI] = -1.97, -0.48; P = .001) and an earlier return to normal activity (-0.99 days; 95% CI = -1.80, -0.17; P = .02). Evaluation of mean pain visual analogue scores (VAS 0-10) over the first 5 and 7 postoperative days failed to demonstrate any significant effect of antibiotic therapy (VAS difference over 5 days = 0.41; -1.18, 2.00; P = .61) (VAS difference over 7 days = -0.64; -3.46, 2.18; P = .66). Cost analysis suggests routine therapy may be cost-effective but did not include analysis of side effects or resistance resulting from antibiotic usage. Conclusion: The results of this systematic meta-analysis suggest that postoperative oral antibiotics do not significantly reduce posttonsillectomy pain but result in an earlier return to normal activity and diet by approximately 1 day. Given the frequency that tonsillectomy is performed, this possible benefit should be weighed against the cost and potential side effects of routine antibiotic therapy.
MSH affects regional perfusion of the brain.

Abstract With the single exception of the occipital cortex, the flow of blood to most regions of the brains of conscious, unrestrained rats was reduced within 10 min after intravenous administration of αMSH. Though these effects were transitory for most regions of the brain, perfusion of cerebellum, pons and medulla, hippocampus, and parietal cortex was still significantly low by 20 min. Assuming that flow changes reflect functional changes, these early responses to αMSH suggest an explanation for the effects of this hormone in which visual learning is improved.
A time-course study of MuLV env gene expression in the AKR thymus: qualitative and quantitative analysis of ecotropic and recombinant virus gene products.

Abstract Low levels of synthesis of two species of MuLV env gene polyprotein (PrENV protein) in thymocytes of 3-month-old AKR mice were identified. Synthesis of PrENV proteins which comigrate with those of ecotropic and recombinant, dualtropic MuLV represented, respectively, 0.03–0.05 and 0.01–0.03% of total cell protein synthesis in these animals. An increase in the rate of synthesis of both PrENV species was observed in animals at 5–6 months of age; ecotropic virus PrENV represented 0.2–0.6% of total protein synthesis and recombinant virus PrENV, 1–2.5% of total protein synthesis in thymocytes of mice of this age. This same increase in env gene expression of both the ecotropic and recombinant virus was induced in 3-month-old animals by intrathymic injection of recombinant MuLV at 4–6 weeks of age. The level of recombinant virus env gene synthesis in thymomas was similar to that observed in thymocytes of 5- to 6-month-old animals and in experimentally injected animals; elevated synthesis of ecotropic virus PrENV protein was detected in 85% of these leukemias. Partial protease digest mapping of the recombinant virus PrENV protein isolated from 23 primary thymomas revealed that the predominant type of recombinant ( 18 23 ) expressed in these cells was that of the MCF 69L1/247 type. A notable finding was the identification of expression of variant ecotropic MuLV in these thymomas. Of ten leukemias studied, eight expressed ecotropic virus PrENV proteins which were distinguishable from that of Akv virus. Four unique ecotropic virus PrENV proteins were observed.
A new Triodopsis juxtidens subspecies (Gastropoda: Pulmonata) from West Virginia, U.S.A.

The Appalachian Mountains of North America hold a unique diversity of land snails, including those within the family Polygyridae genus Triodopsis . West Virginia has ten or more representatives of the genus (Hubricht, 1985), displaying variations upon the conchological theme of a depressed heliciform shape with a reflected peristome bearing three lamellae. However, it remains unclear whether all of the recognized variants on this theme represent species as commonly defined. In the case of the Triodopsis juxtidens (Pilsbry, 1894) subgroup as defined by Emberton (1988)— T. juxtidens , T. discoidea (Pilsbry, 1904), T. neglecta (Pilsbry, 1899), and T. pendula Hubricht, 1952—no penial morphology or allozyme differences are known (Emberton, 1988). Conversely, mitochondrial DNA analysis that included five T. juxtidens specimens suggests this putative species is not monophyletic (Perez et al. , 2014). Rampant variation in shell morphology among Triodopsis species creates further taxonomic and identification challenges. Without additional supporting evidence for species-level differences, such as anatomical and genetic analyses, a conservative taxonomic approach is to recognize regionally distinct forms as subspecies. A unique form from the upper Bluestone River watershed is described here as Triodopsis juxtidens robinae subsp. nov.
Two-Year-Olds Will Name Artifacts By Their Functions

Do young children take functional information into account in naming artifacts? In three studies of lexical categorization, 112 children 2 years of age learned new names for novel artifacts with novel functions and then extended the names to new objects. The objects were designed to have functions that were causally related in simple and compelling ways to perceptible aspects of their physical structure. Despite only minimal opportunity to familiarize themselves with the objects, children generalized the names in accordance with the objects' functions. This result obtained even when children had to discover the functions of the named objects on their own (Experiment 2) and when all the test objects had some discernible function (Experiment 3). Two-year-olds name by function when they can make sense of the relation between the appearances and the functions of artifacts.
Evidence on the Financial Capability of Elder Workers Facing Lump-Sum Retirement Plan Distributions

Late career workers with lump-sum retirement plans face important financial decisions. Because ability and confidence interact when making financial decisions, this paper asks two related questions: Are workers approaching retirement financially capable of making decisions regarding lump-sum retirement benefits? Do they see themselves as capable? Comparing self-assessed measures of financial capacity to more objective measures reveals patterns of under and overconfidence in financial matters by socio-economic group. Comparing questions correlation to overall score, compound interest concepts are found to be strongly correlated with overall financial literacy. Findings suggest that financial planners may act as partial compensation for a lack of financial literacy, especially among the wealthy. This papers findings support: (1) developing tools that help potential clients engage and assess the work of financial managers, (2) including both self-assessment and objective finance questions on planners’ client intake surveys and (3) facilitating client understanding of compound interest concepts.
Distinct BOLD Activation Profiles Following Central and Peripheral Oxytocin Administration in Awake Rats

A growing body of literature has suggested that intranasal oxytocin (OT) or other systemic routes of administration can alter prosocial behavior, presumably by directly activating OT sensitive neural circuits in the brain. Yet there is no clear evidence that OT given peripherally can cross the blood-brain-barrier at levels sufficient to engage the OT receptor. To address this issue we examined changes in blood oxygen level dependent (BOLD) signal intensity in response to peripheral OT injections (0.1, 0.5 or 2.5 mg/kg) during functional magnetic resonance (fMRI) in awake rats imaged at 7.0 tesla. These data were compared to OT (1ug/5 µl) given directly to the brain via the lateral cerebroventricle. Using a 3D annotated MRI atlas of the rat brain segmented into 171 brain areas and computational analysis we reconstructed the distributed integrated neural circuits identified with BOLD fMRI following central and peripheral OT. Both routes of administration caused significant changes in BOLD signal within the first 10 min of administration. As expected, central OT activated a majority of brain areas known to express a high density of OT receptors e.g., lateral septum, subiculum, shell of the accumbens, bed nucleus of the stria terminalis. This profile of activation was not matched by peripheral OT. The change in BOLD signal to peripheral OT did not show any discernible dose-response. Interestingly, peripheral OT affected all subdivisions of the olfactory bulb, in addition to the cerebellum and several brainstem areas relevant to the autonomic nervous system, including the solitary tract nucleus. The results from this imaging study do not support a direct central action of peripheral OT on the brain. Instead, the patterns of brain activity suggest that peripheral OT may interact at the level of the olfactory bulb and through sensory afferents from the autonomic nervous system to influence brain activity.
Clerkship Curricular Revision Based on the Ambulatory Pediatric Association and the Council on Medical Student Education in Pediatrics Guidelines: Does It Make a Difference?

Objective. To compare general pediatric knowledge acquisition and clinical problem-solving skills by students pre- and postcurricular reform based on the 1994 Ambulatory Pediatric Association and the Council on Medical Student Education in Pediatrics (APA–COMSEP) curricular guidelines. Setting. A large, urban academic medical center. Subjects. Third-year medical students on a required clerkship in Pediatrics. Intervention. Pre- and postcurricular revision, the students were given both the National Board of Medical Examiners (NBME) Pediatric Subject Examination and an objective examination, which was developed in-house, based on the APA–COMSEP guidelines (Pediatric Clerkship Examination [PCE]). Baseline data before curricular revision were obtained on 52 students from May 1995 to May 1996. After curricular redesign in May 1996, data were obtained on 42 students from May 1996 to May 1997. Curricular revision focused on the following: defining educational principles, selecting teaching strategies, defining learning objectives, implementing the curriculum, and evaluating the students with an examination. Results. Before curricular revision, the average NBME score was 521 ± 122. The average PCE score was 53.7% ± 10.1%. After curricular revision, the average NBME score was 520 ± 109, and the average PCE score was 67.7% ± 8.4%. Content areas showing the greatest improvement were fluids and electrolytes, issues pertaining to the newborn, and health supervision. Conclusions. Our baseline data indicate that despite spending two thirds of the clerkship in the ambulatory setting, students did not acquire adequate general pediatric knowledge or clinical problem-solving ability. After broad clerkship revision based on the APA–COMSEP Core Curriculum, students9 acquisition of general pediatric knowledge and clinical problem-solving improved significantly, as measured by the PCE. The overall NBME Pediatric Subject Examination scores did not reflect this increased acquisition of general pediatric knowledge.
Faculty Perspectives on International Accounting Topics.

Abstract Given the increasing globalization of business, including the widening acceptance of International Financial Reporting Standards (IFRS) in the capital markets, the international dimension is of great importance to the accounting profession. The international accounting course plays a key role in the accounting curriculum in providing students with information about this critical area of accounting. This study examines the relative importance of various international accounting topics through a survey of members of the American Accounting Association's International Accounting Section. Results are compared with those of prior studies in order to determine whether and to what extent perspectives have changed over time. The findings should be helpful for faculty designing or updating an international accounting course or curriculum or desiring to integrate international issues into various accounting courses. They should also help practitioners identify with which areas their new hires are likely to be more familiar.
The variance of population characteristics in stable populations, with applications to the distribution of income.

Summary Stable population theory has recently been used to analyse the effects of changes in fertility and mortality on economic variables such as income per head. In this paper more general results are derived to describe the effects of changing vital rates on the variance and higher moments of the distribution of some age-dependent variable. Simple analytical expressions are derived which decompose the effects of changes in age structure into the effects on inter-cohort and intra-cohort variance. The results are easily applied to standard measures of the distribution of income. By combining the analytical results with actual age profiles of income and income variance from the United States and Brazil it is observed that both the magnitude and direction of the effects of population growth on measured inequality are sensitive to the specific age profiles used. The most surprising result is that the Brazilian age profiles suggest that higher growth rates may actually reduce measured inequality, although th...
Pharmacokinetics of Nikkomycin Z after Single Rising Oral Doses

Nikkomycin Z is an antifungal drug that inhibits chitin synthase. This agent is under development as an orphan product for treatment of coccidioidomycosis. Safety and pharmacokinetics of nikkomycin Z were evaluated in healthy male subjects following single, rising oral doses ranging from 250 mg to 2,000 mg. A total of 12 subjects were recruited and divided into two groups. Group 1 (n = 6) received two out of three doses of 250 mg, 1,000 mg, or 1,750 mg and a placebo randomly in place of one of the doses. Group 2 (n = 6) received two out of three doses of 500 mg, 1,500 mg, or 2,000 mg and a placebo in place of one of the doses. Subjects were confined to the study unit overnight prior to dosing, and 12 blood samples were collected over 24 h postdosing while subjects were confined. Subjects returned for additional blood samples and safety evaluations at 48 h and 72 h after each dose. There was a 2-week washout period between doses. Plasma drug concentrations were determined using a validated high-performance liquid chromatography method. Nikkomycin Z was absorbed after oral administration, reaching a maximum concentration in serum of 2.21 microg/ml at 2 h postdose and an area under the concentration-time curve from 0 h to infinity of 11.3 microg x h/ml for the 250-mg dose. Pharmacokinetics appeared linear over the range of 250 to 500 mg; however, relative bioavailability was about 62 to 70% for the 1,000-mg dose and 42 to 47% for doses between 1,500 and 2,000 mg. The mean terminal half-life ranged from 2.1 to 2.5 h and was independent of dose. No serious or dose-related adverse events were observed. This study provides a basis for pharmacokinetic simulations and continued studies of nikkomycin Z administered in multiple doses.
Long‐lasting effects on nitrogen cycling 12 years after treatments cease despite minimal long‐term nitrogen retention

Atmospheric deposition of biologically active nitrogen (N) has increased dramatically over the past 60 years, with far-reaching impacts on the structure and function of many ecosystems. Much research has examined the initial impacts of N enrichment; however, few studies have been multidecadal, and even fewer long-term studies have examined the longevity of N-induced impacts on N cycling after inputs cease. Here, we address this gap by reporting the state of key N pools and fluxes in a Minnesota grassland for plots that received N addition for 10 years and then none for 12 years, in comparison with plots that received annual N treatment for the entire 22 years. We found weak evidence for long-term N retention in plots that ceased receiving treatment; and in plots that continued to receive N over the 22-year period, retention that was high after 12 years (50‐100% of inputs) was greatly reduced after 22 years (to 15%). In spite of this, net N mineralization rates remained elevated in plots that ceased receiving treatment 12 years prior, likely because N-rich litter maintained higher N-cycling rates. These results suggest (1) some systems do not retain much deposited N, with potentially large impacts on downstream habitats; (2) the previously reported high retention efficiencies for this and many other terrestrial ecosystems may be relatively short-lived as N sinks become saturated over time; and (3) the effects of even small amounts of retained N in N-limited environments may be particularly long-lasting. In total, these findings highlight the importance of long-term studies in evaluating the impacts of chronic N deposition to ecosystems, and urge additional research examining dynamics following N cessation to evaluate the reversibility of these impacts.
Status Integration and Suicide: Occupational, Marital, or Both?

The findings of two between-columns tests of the theory linking status integration and the suicide rate (Stafford & Gibbs 1985, 1988) suggest that only occupational integration is relevant. However, in numerous within-column tests there is a substantial negative association between marital integration and the suicide rate among marital statuses within each age group. The present research demonstrates that the substantial negative association holds generally for six age groups of black females, black males, white females, and white males in the U.S., even when the amount of occupational integration for each marital status is taken into account. Hence, although the theory's predictive accuracy would exceed that of contenders even if limited to occupational integration, the findings caution against exclusion of marital integration
Susceptibility of Florida Mosquitoes to Infection with Chikungunya Virus

Chikungunya virus (CHIKV) has caused recent, large epidemics on islands in the Indian Ocean, raising the possibility of more widespread CHIKV epidemics. Historically, CHIKV has been vectored by Aedes aegypti, but these outbreaks likely also involved Ae. albopictus. To examine the potential for an outbreak of CHIKV in Florida, we determined the susceptibility to CHIKV of F1 Ae. aegypti and Ae. albopictus from Florida. In addition, we also evaluated two well-characterized laboratory strains (Rockefeller and Lake Charles) of these species. We determined infection and dissemination rates as well as total body titer of mosquitoes 7 days post-exposure (pe) (Ae. albopictus) and 3, 7, and 10 days pe (Ae. aegypti). All mosquito strains were susceptible to both infection and dissemination, with some variation between strains. Our results suggest Florida would be vulnerable to transmission of CHIKV in urban and rural areas where the two vector species occur.
Evaluation policy and evaluation practice

The author develops the basic idea of evaluation policy, describes a practical model for development and revision of evaluation policies (including a taxonomy, structure, and set of principles), and suggests critical challenges and opportunities for the future of evaluation policy. An evaluation policy is any rule or principle that a group or organization uses to guide its decisions and actions when doing evaluation. Every entity that engages in evaluation, including government agencies, private businesses, and nonprofit organizations, has evaluation policies. Sometimes they are explicit and written; more often they are implicit and ad hoc principles or norms that have simply evolved over time.