cssi/SciSciGPT-SciSciNet huggingface dataset:
Hybrid approaches for accelerated convergence of block-Jacobi iterative methods for solution of the neutron transport equation

Abstract The Parallel Block Jacobi (PBJ) [1] , [2] scheme is an iterative method with application in neutron transport solution which requires asynchronous sub-domain interfaces, where asynchronous here means flux continuity is not imposed across sub-domain interfaces. In this work, we present the development, analysis, and testing of hybrid methods which utilize both PBJ-type methods and synchronous sweep-based methods in a single iterative step. These methods are developed to reduce the penalty to iterative performance of the former incurred in problems containing optically thin cells, while maintaining the PBJ method's applicability to massively parallel solution on unstructured grids. As a prelude to this ultimate goal, this study is conducted in serial operation on 2-D Cartesian grids to facilitate implementation of the various tested iterative methods, to enable the reported spectral analysis, and for shorter computational execution times allowing the large amounts of performance data to be collected. The analysis consists of two Fourier analyses, demonstrating the sequential execution of a PBJ method and SI to be iteratively robust with respect to optical thickness. The results of these analyses and preliminary computational experimentation demonstrate the effectiveness of methods that execute PBJ and SI only in optically thick and thin regions of a problem, respectively. Further experimentation, including a parametric study, then demonstrates this approach to be effective when the thin region is solved using Inexact Parallel Block Jacobi (IPBJ), with sub-domains of a size such that the applicability to massively parallel solution on unstructured grids is not diminished. Finally, testing on realistic test problems containing large void regions confirms the viability of this approach. Performance comparisons include the traditional iterative acceleration methods Diffusion Synthetic Acceleration, Partial-current Nonlinear Diffusion Acceleration, and Adjacent-cell Preconditioner. The results show that while the hybrid PBJ methods generally consume more iterations than these traditional methods, our hybrid approach maintains an iteration count on the same order of magnitude as these acceleration methods, which are not fully developed for massively parallel solution on unstructured grids.
Mismatched Regulation: Genetically Modified Mosquitoes and the Coordinated Framework for Biotechnology

Author(s): Lin, Albert | Abstract: For over thirty years, the Coordinated Framework for Regulation of Biotechnology (“Coordinated Framework” or “Framework”) has guided federal regulation of biotechnology products. The Framework relies on a patchwork of laws to allocate oversight of biotechnology products among federal regulatory agencies. The Obama Administration’s 2017 update to the Framework offered the potential to account for new technological developments and to respond to criticisms of the Framework. However, as illustrated by the government’s response to the proposed experimental release of a genetically modified mosquito in the Florida Keys, this potential remains largely unrealized. Oxitec, a British biotechnology company, has genetically modified a mosquito so that male mosquitoes pass on a lethal genetic trait to any offspring. The Food and Drug Administration (“FDA”) evaluated Oxitec’s mosquito as an investigational new animal drug, determined that the proposed field trial would not significantly impact the environment, and turned the matter over to local authorities to decide whether to proceed with the release. While the federal government took these actions before finalizing the Framework update, the update did not significantly change the Framework’s basic approach. As new techniques for manipulating and editing genes offer the prospect of additional genetically modified organisms (“GMOs”), the federal government’s handling of the Oxitec mosquito offers a useful case study regarding the inadequacy of current legal frameworks for new biotechnologies. Ideally, the decision-making process for such technologies would assess and manage relevant risks, acknowledge and address sources of uncertainty and ignorance, engage stakeholders and the public and attempt to reflect their values, and build public confidence that the process is effective and legitimate.
Information Source Use and Social Media Engagement: Examining their Effects on Origin of COVID-19 Beliefs:

Coronavirus Disease 2019 (COVID-19), a highly infectious virus transmitted through droplets from sneezes and coughs, was declared a global pandemic in 2020. Measures implemented by organizations as...
Anterior uveitis as an atypical presentation of large granular lymphoma in a caracal (Caracal caracal)

An 11-year-old, female, spayed caracal (Caracal caracal) presented with a 3-month history of intermittent anorexia, vomiting, and weight loss. At examination, bilateral anterior uveitis with anisocoria was present. Further examination under general anesthesia revealed the anterior chamber of the right eye contained copious amounts of thick fibrin, hypopyon, and hyphema obscuring the ventral pupil margin and ventral iris. Aqueous paracentesis revealed a cytologic diagnosis of large granular lymphoma. Additional antemortem diagnostics (computed tomography, ultrasound with fine needle aspiration, and cytology) confirmed the diagnosis of multicentric large granular lymphoma with associated intestinal perforation. Necropsy and histopathology confirmed multicentric large granular lymphoma in the right eye, jejunum, mesenteric lymph nodes, and right kidney. Large granular lymphoma in nondomestic felids is likely rare since it has not been previously reported, but should be considered as a differential in any felid species with anterior uveitis or when lymphoma is considered. In the case of this caracal, the use of aqueous paracentesis with cytology was a powerful diagnostic.
Information loss in digital documents: Gurmukhi fonts perspective

Digital representation of Indic script in digital documents remain one of the prominent problems in recent era. The fonts have its effect in the continuation of digital documents and the need of fonts cannot be overemphasized in digital world, when one comes to preservation of Indie script documents for India digital libraries. Gurmukhi script is one of the most prominent scripts of India and is used to write Punjabi Language. Punjabi is one of the most widely spoken languages in the world with more than 2 million users only in India. Due to such large number of users, the digitalization of language becomes apparently useful. Earlier Gurmukhi fonts were developed using ASCII character encoding scheme which was basically meant for English language and not intended to provide direct support to foreign languages. Moreover Gurmukhi fonts were developed without following any mapping standardization which leads to development of numerous fonts with different mapping tables. As of the evolution of different mapping schemes for different fonts the substitution between two Gurmukhi fonts leads to information loss in documents. This paper makes an attempt to demonstrate and understand the loss of information because of Gurmukhi font substitution by another with an experimental setup. The outputs of the setup were analysed on parameters as percentage of information loss, overall accuracy and weighted kappa statistics.
On Producing Multiple Solutions Using Repeated Trials

The number of trials that is required by an algorithm to produce a given fraction of the problem solutions with a specified level of confidence is analyzed. The analysis indicates that the number of trials required to find a large fraction of the solutions rapidly decreases as the number of solutions obtained on each trial by an algorithm increases. In applications where multiple solutions are sought, this decrease in the number of trials could potentially offset the additional computational cost of algorithms that produce multiple solutions on a single trial. The analysis framework presented is used to compare the efficiency of a homotopy algorithm to that of a Newton method by measuring both the number of trials and the number of calculations required to obtain a specified fraction of the solutions.
A generic network interface architecture for a networked processor array (NePA)

Recently Network-on-Chip (NoC) technique has been proposed as a promising solution for on-chip interconnection network. However, different interface specification of integrated components raises a considerable difficulty for adopting NoC techniques. In this paper, we present a generic architecture for network interface (NI) and associated wrappers for a networked processor array (NoC based multiprocessor SoC) in order to allow systematic design flow for accelerating the design cycle. Case studies for memory and turbo decoder IPs show the feasibility and efficiency of our approach.
iTunes Metadata and Classical Music: Issues and Solutions for Crowdsourced Metadata in iTunes

Crowdsourced metadata available in iTunes is too often insufficient or even incorrect for classical music recordings. Listeners find themselves frustrated when the only options iTunes provides are illogical. What we need is a group of professionals who are experts in music and information organization to clean things up. Enter the Music Library Association. The author proposes that this national group with ten regional chapters divide the work of providing improved metadata for classical recordings, using an open source program such as freedb. Working with Gracenote, individual music librarians could also correct existing data and reduce instances of a user encountering poor information.
Exploring optimal cost-performance designs for Raw microprocessors

The semiconductor industry roadmap projects that advance in VLSI technology will permit more than one billion transistors on a chip by the year 2010. The MIT Raw microprocessor is a proposed architecture that strives to exploit these chip-level resources by implementing thousands of tiles, each comprising a processing element and a small amount of memory, coupled by a static two-dimensional interconnect. A compiler partitions fine-grain instruction-level parallelism across the tiles and statically schedules inter-tile communication over the interconnect. Because Raw microprocessors fully expose their internal hardware structure to the software, they can be viewed as a gigantic FPGA with coarse-grained tiles, in which software orchestrates communication over static interconnections. One open challenge in Raw architectures is to determine their optimal grain size and balance. The grain size is the area of each tile, and the balance is the proportion of area in each tile devoted to memory, processing, communication, and I/O. If the total chip area is fixed, more area devoted to processing will result in a higher processing power per node, but will lead to a fewer number of tiles. This paper presents an analytical framework using which designers can reason about the design space of Raw microprocessors. Based on an architectural model and a VLSI cost analysis, the framework computes the performance of applications, and uses an optimization process to identify designs that will execute these applications most cost-effectively.
Comprehensive analysis of post‐diagnostic prostate‐specific antigen kinetics as predictor of a prostate cancer progression in active surveillance patients

What's known on the subject? and What does the study add? A significant proportion of patients diagnosed with prostate cancer do not require immediate treatment and could be managed by active surveillance, which usually includes serial measurements of prostate-specific antigen (PSA) levels and regular biopsies. The rate of rise in PSA levels, which could be calculated as PSA velocity or PSA doubling time, was previously suggested to be associated with the biological aggressiveness of prostate cancer. Although these parameters are obvious candidates for predicting tumour progression in active surveillance patients, earlier studies that examined this topic provided conflicting results. Our analysis showed that PSA velocity and PSA doubling time calculated at different time-points, by different methods, over different intervals, and in different sub-groups of active surveillance patients provide little if any prognostic information. Although we found some significant associations between PSA velocity and the risk of progression as determined by biopsy, the actual clinical significance of this association was small. Furthermore, PSA velocity did not add to the predictive accuracy of total PSA. Objective To study whether prostate-specific antigen (PSA) velocity (PSAV) and PSA doubling time (PSADT) are associated with biopsy progression in patients managed by active surveillance. Patients and Methods Our inclusion criteria for active surveillance are biopsy Gleason sum <7, two or fewer positive biopsy cores, ≤20% tumour present in any core, and clinical stage T1–T2a. Changes in any of these parameters during the follow-up that went beyond these limits are considered to be progression. This study included 250 patients who had at least one surveillance biopsy, an available PSA measured no earlier than 3 months before diagnosis, and at least one PSA measurement before each surveillance biopsy. We evaluated the association between PSA kinetics and progression at successive surveillance biopsies in different sub-groups of patients by calculating the area under the curve (AUC) as well as sensitivity and specificity of different thresholds. Results Over a median follow-up of 3.0 years, the disease of 64 (26%) patients progressed. PSADT was not associated with biopsy progression, whereas PSAV was only weakly associated with progression in certain sub-groups. However, incorporation of PSAV in models including total PSA resulted in a moderate increase in AUC only when the entire cohort was analysed. In other sub-groups the predictive accuracy of total PSA was not significantly improved by adding PSAV. Conclusions Our findings confirm that PSA kinetics should not be used in decision-making in patients with low-risk prostate cancer managed by active surveillance. Regular surveillance biopsies should remain as the principal method of monitoring cancer progression in these men.
Impact of race in a predominantly African-American population of patients with low/intermediate risk prostate cancer undergoing radical prostatectomy within an equal access care institution

To study the impact of race in an equal access care institution with a predominantly African-American (AA) population. We retrospectively reviewed data from 222 men with low risk (LR) or intermediate risk (IR) prostate cancer who underwent radical prostatectomy at the New York Harbor VA between 2003 and 2011. Biochemical relapse, distant control, and prostate cancer-specific survival were analyzed using the Kaplan–Meier method and compared using the log-rank test. Univariate and multivariate Cox regression modeling was performed to determine the impact of covariates on biochemical outcome. Most patients (65.3 %) were AA. The median follow-up was 58 months, and 89.6 % of patients were followed for a minimum of 2 years after their surgery. Analyzing the whole cohort, the biochemical control was improved in Caucasian patients compared with AA (90.2 vs. 75.4 %, p = 0.008). On subgroup analysis, for IR disease, this difference was no longer significant, 80.5 % for Caucasians versus 69.8 % for AA (p = 0.36). However, for LR disease, the 5-year biochemical control remained significantly improved for Caucasians compared with AA, with a 5-year biochemical control of 97.6 versus 81.7 %, p = 0.006. On multivariate analysis, AA race was a significant predictor for biochemical recurrence (HR 2.69, 95 % CI 1.27–5.65, p = 0.009). There were no differences between the two groups regarding distant control (p = 0.14) or prostate cancer-specific survival (p = 0.29). In this predominant AA population with equal access to medical care, AA race is an independent predictor of biochemical recurrence after prostatectomy in men with LR or IR prostate cancer.
Total synthesis of the reputed structure of alcyonin and reassignment of its structure.

Introduction of the C4 hydroxyl group by an epoxy ester rearrangement is a pivotal step in the first total synthesis of the purported structure of alcyonin. As the spectral data for diol acetate 3 do not match those reported for alcyonin, the structure of this marine diterpene must be revised. Reexamination of NMR spectra, MS data, and chemical transformations of natural alcyonin suggests that the structure of this marine metabolite is allylic peroxide 15.
Effects of pressure on swimming behavior in planula larvae of the coral Porites astreoides (Cnidaria, Scleractinia)

Abstract Mechanisms governing the behavior of coral planulae are not well understood, particularly those manifesting themselves between the time when the larvae are released and when they settle. Larvae from the hermatypic coral Porites astreoides Lamarck were exposed to different levels of hydrostatic pressure—103.4, 206.9, 310.3, 413.8, and 517.1 kPa (including ambient pressure). Data were collected at stops of the above pressures for 15 min each, respectively. This was done in both an increasing sequence and a decreasing one. When exposed to increases in pressure from 103.4 kPa, larvae swam upward (negative barotaxis) in a spiraling motion. Upon exposure to decreasing pressure from 517.1 kPa, larvae moved downward (positive barotaxis), but the magnitude of the vertical movement was much less than in the case of increasing pressure. This suggests that these larvae are more sensitive to increased pressure than decreasing pressure. High variance was also observed in the responses of these larvae at both the intra- and inter-colony levels. Thus, this behavioral trait is variable within the population. The trait may be genetically based, and thus may be susceptible to alteration by natural selection, although this remains to be demonstrated. This study is the first to document these behavioral mechanisms in coral larvae.
488 Intraductal Papillary Mucinous Neoplasms and the Risk of Diabetes Mellitus in Patients Undergoing Resection vs. Observation

Objective The aim of this study is to determine the prevalence of diabetes mellitus (DM) in patients with intraductal papillary mucinous neoplasm of the pancreas (IPMN) and compare rates of new/progressive DM between IPMN patients undergoing pancreatectomy versus observation.
Quantum confined electron-phonon interaction in silicon nanocrystals.

We study the micro-Raman spectra of colloidal silicon nanocrystals as a function of size, excitation wavelength, and excitation intensity. We find that the longitudinal optical (LO) phonon spectrum is asymmetrically broadened toward the low energy side and exhibits a dip or antiresonance on the high-energy side, both characteristics of a Fano line shape. The broadening depends on both nanocrystal size and Raman excitation wavelength. We propose that the Fano line shape results from interference of the optical phonon response with a continuum of electronic states that become populated by intraband photoexcitation of carriers. The asymmetry exhibits progressive enhancement with decreasing particle size and with increasing excitation energy for a given particle size. We compare our observations with those reported for p- and n-doped bulk Si, where Fano interference has also been observed, but we find opposite wavelength dependence of the asymmetry for the bulk and nanocrystalline Si. Our results have importa...
Compatibility of various materials with oral tissues. I: The components in composite restorations

The basic ingredients in composite restorative materials include: monomers, polymerization stabilizers, color stabilizers, polymerization initiators, polymerization accelerators, inorganic reinforcing fillers, and coupling agents. Typical members of each category are discussed.
Deployment of community health workers across rural sub-Saharan Africa: financial considerations and operational assumptions

OBJECTIVE: To provide cost guidance for developing a locally adaptable and nationally scalable community health worker (CHW) system within primary-health-care systems in sub-Saharan Africa. METHODS: The yearly costs of training, equipping and deploying CHWs throughout rural sub-Saharan Africa were calculated using data from the literature and from the Millennium Villages Project. Model assumptions were such as to allow national governments to adapt the CHW subsystem to national needs and to deploy an average of 1 CHW per 650 rural inhabitants by 2015. The CHW subsystem described was costed by employing geographic information system (GIS) data on population, urban extents, national and subnational disease prevalence, and unit costs (from the field for wages and commodities). The model is easily replicable and configurable. Countries can adapt it to local prices, wages, population density and disease burdens in different geographic areas. FINDINGS: The average annual cost of deploying CHWs to service the entire sub-Saharan African rural population by 2015 would be approximately 2.6 billion (i.e. 2600 million) United States dollars (US$). This sum, to be covered both by national governments and by donor partners, translates into US$ 6.86 per year per inhabitant covered by the CHW subsystem and into US$ 2.72 per year per inhabitant. Alternatively, it would take an annual average of US$ 3750 to train, equip and support each CHW. CONCLUSION: Comprehensive CHW subsystems can be deployed across sub-Saharan Africa at cost that is modest compared with the projected costs of the primary-health-care system. Given their documented successes, they offer a strong complement to facility-based care in rural African settings.
Organization and regulation of the Corynebacterium glutamicum hom-thrB and thrC loci

The genes encoding the three terminal enzymes in the threonine biosynthetic pathway, homoserine dehydrogenase (hom), homoserine kinase (thrB) and threonine synthase (thrC) have been isolated from Corynebacterium glutamicum. The C. glutamicum hom and thrB genes were subcloned on a 3.6 kb SalI-generated chromosomal fragment. The C. glutamicum thrC gene was shown not to be linked to the hom-thrB locus. L-methionine represses the cloned homoserine dehydrogenase and homoserine kinase similar to that of the chromosomally encoded hom and thrB gene products. Northern hybridization analysis demonstrates that this repression is mediated at the level of transcription and that hom-thrB represents an operon in C. glutamicum.
Enhanced performance core-sell Si/CdS nanowires heterojunction solar cell device

In this work, we have fabricated Core-Shell Si/CdS nanowires heterojunction structures by preparing n type cadmium sulfite nanoparticles (CdS-NPs) on a large area of vertically alight p type of Si nanowires (Si-NWs). The CdS-NPs were fabricated by chemical bath deposition (CBD), while the Si wafer was etched in chemical solution to obtain Si-NWs. SEM images show 2-D CdS-NPs are well adhesive on Si-NWs. The Optical properties of different thicknesses CdS-NPs thin films fabricated on glass slide and on Si-NWs were studied by measuring their UV-Visible absorption and Raman spectra. The structure of CdS-NPs thin film was investigated by XRD. We deposited Al doped ZnO (AZO) film on CdS-NPs/Si-NWs heterojunction as electrode to improve the performance of the heterojunction devices. We have also studied the performance of the solar cell before and after depositing AZO, its dependence on the length of Si-NWs, and on the thickness of the CdS-NPs layers. The results of these studies are presented in this paper.
The cellular immunology of bovine paratuberculosis: the predominant response is mediated by cytotoxic gamma/delta T lymphocytes which prevent CD4+ activity.

Abstract Peripheral blood T-cell subsets were obtained from an experimentally sensitized bovine and from nine bovines naturally infected with Mycobacterium paratuberculosis and tested for their ability to respond to antigen. It was determined that following antigen challenge, proliferative responses followed a biphasic pattern: an initial CD4 + proliferative response, a period of anergy, and a final response governed by gamma/delta T lymphocytes. The anergic phase was characterized by a dramatic drop in peripheral blood CD4 + cells; the nature of the non-responsiveness could not be determined. The anergic phase was followed by increased proliferative responses of non-MHC restricted gamma/delta T lymphocytes. Although CD4 + cells had the ability to proliferate in response to M. paratuberculosis antigens in the absence of gamma/delta T cells, antigen-primed CD4 + lymphocytes failed to incorporate [ 3 H]-thymidine in the presence of gamma/delta T cells and M. paratuberculosis antigen. It was concluded that M. paratuberculosis-spectfic gamma/delta T lymphocytes have immunoregulatory function and exhibit cytotoxic activity against antigen-primed CD4 + helper cells. The data suggest that the inability of effector cell populations to prevent intracellular proliferation of M. paratuberculosis may be a result of cytotoxic killing of the T helper lymphocyte population required for macrophage activation.
Water-soluble polymer-bound biomimetic analogues of cytochrome C oxidase catalyze 4e- reduction of O2 to water.

Activity toward catalytic O2 reduction by polyacrylic acid (PAA) and polyvinylpyridine (PVP) polymers containing functional analogues of the O2-reducing site of cytochrome c oxidase (CcO) has been studied in solution and on the electrode surface. Pronounced effects of the porphyrin microenvironment on the selectivity and turnover frequency of the catalysts were observed.
Distribution of total and methyl mercury in sediments along Steamboat Creek (Nevada, USA)

In the late 1800s, mills in the Washoe Lake area, Nevada, used elemental mercury to remove gold and silver from the ores of the Comstock deposit. Since that time, mercury contaminated waste has been distributed from Washoe Lake, down Steamboat Creek, and to the Truckee River. The creek has high mercury concentrations in both water and sediments, and continues to be a constant source of mercury to the Truckee River. The objective of this study was to determine concentrations of total and methyl mercury (MeHg) in surface sediments and characterize their spatial distribution in the Steamboat Creek watershed. Total mercury concentrations measured in channel and bank sediments did not decrease downstream, indicating that mercury contamination has been distributed along the creek's length. Total mercury concentrations in sediments (0.01-21.43 microg/g) were one to two orders of magnitude higher than those in pristine systems. At 14 out of 17 sites, MeHg concentrations in streambank sediments were higher than the concentrations in the channel, suggesting that low banks with wet sediments might be important sites of mercury methylation in this system. Both pond/wetland and channel sites exhibited high potential for mercury methylation (6.4-30.0 ng g(-1) day(-1)). Potential methylation rates were positively correlated with sulfate reduction rates, and decreased as a function of reduced sulfur and MeHg concentration in the sediments. Potential demethylation rate appeared not to be influenced by MeHg concentration, sulfur chemistry, DOC, sediment grain size or other parameters, and showed little variation across the sites (3.7-7.4 ng g(-1) day(-1)).
Intrathyroidal Fetal Microchimerism in Graves’ Disease

During pregnancy, fetal cells are known to reach the maternal circulation and infiltrate a variety of tissues (fetal microchimerism). Although the presence of such cells has the potential to modulate the maternal immune response to both self antigens and fetal alloantigens, the degree of their influence remains unclear. The hyperthyroidism of Graves' disease frequently abates during pregnancy and exacerbates after childbearing. Thus, we have hypothesized that fetal cells in the maternal circulation and tissues may influence this decrescendo to crescendo pattern of autoimmune thyroid disease. Part of this hypothesis was tested using an ELISA-PCR for the detection of DNA for a male-specific gene, sex-determining region Y. The sensitivity of this assay was the equivalent of approximately 1 male cell among 10(5) female cells. We initially examined paraffin-embedded thyroid tissues and detected male cells in 4 of 20 female Graves' thyroid specimens, but not in 6 of 6 female adenoma specimens. Using frozen thyroid tissue specimens, an additional 6 of 7 Graves' disease samples demonstrated intrathyroidal fetal microchimerism, whereas 1 of 4 female samples with thyroid nodules showed male cells. The greater detection of the sex-determining region Y gene in frozen female thyroid tissues was probably due to DNA fragmentation in the paraffin-derived samples. In summary, we demonstrated that intrathyroidal fetal microchimerism was common and profound in female patients with Graves' disease. Thus, fetal male cells are valid candidates for modulating autoimmune thyroid disease in pregnancy and postpartum.
Active thymus derived suppressor lymphocytes in human cord blood

A FOETUS carries antigens that are foreign to its mother, but the mother does not routinely reject it as an allograft. The fate of the foetus may thus depend on preventing or blocking the ability of the immune system of the mother to respond to alien foetal antigens. Clearly, this is a complex process which may involve several mechanisms1–6. One mechanism implicates the active blocking of the immunological capacity of the mother to respond to her foetus5,6. We reported previously that T lymphocytes taken from cord blood of human newborns inhibits their own mothers' lymphocytes from entering mitosis6,7. We have studied the subpopulations of T lymphocytes in human cord blood and ascertained their ability to inhibit both the division of lymphocytes and the production of immunoglobulin by lymphocytes obtained from the mother. We report here that active T suppressor cells occur in cord blood, that these T suppressor cells bear IgG receptors; and that the T cells bearing IgG receptors inhibit both mitosis of and immunoglobulin production by lymphocytes from the mother.
Potential-Step Chronocoulometric and Quartz Crystal Microbalance Investigation of Underpotentially Deposited Tl on Au(111) Electrodes

Tl underpotentially deposited (upd) on Au(111) has been studied using potential-step chronocoulometry and electrochemical quartz crystal microbalance to determine the actual coverage of Tl. At anodic potentials, Tl adsorbs to the surface at a coverage that slowly increases up to 0.55 ML. At more cathodic potentials, the coverage rises sharply to a plateau of 0.79 ML where the surface is covered with a close-packed Tl monolayer. The electrosorption valency calculated based on this coverage data indicates that the low coverage overlayer is incompletely discharged but that the overlayer undergoes further discharge during the voltammetric features associated with complete monolayer formation. Voltammetric experiments also indicate that the presence of hydroxide anions plays a role in stabilizing the charged low coverage phase. The implications of this structural and charge information for the catalytic activity of the Tl upd system are discussed.
Palladium(II)-Directed Self-Assembly of Dynamic Donor−Acceptor [2]Catenanes

Highly efficient syntheses of donor−acceptor [2]catenanes were developed using a combination of templation and reversible metal−ligand coordination. The desired [2]catenanes were obtained within minutes through a five-component assembly, involving a donor-containing crown ether, an acceptor-containing ligand, two Pd(II) metal centers, and a dipyridyl ligand. The [2]catenane formation was characterized by 1H NMR and UV−vis spectroscopies and cold-spray ionization mass spectrometry. In particular, great translational selectivity was observed when a crown ether with two different donor units was employed.
The synarcual cartilage of batoids with emphasis on the synarcual of Rajidae

Comparison of embryonic specimens with juvenile and mature specimens of other skates indicates that the relative developmental sequence of events is maintained among several taxa within larger clades. However, there is a fundamental difference between the pattern of chondrification and the pattern of calcification in skates. Early in ontogeny a short synarcual surrounds the first free vertebral centrum. Additional neural arch segments are incorporated from anterior to posterior and the relative length of the synarcual cartilage to total length of the body normalizes early. A secondary direction of chondrification, from ventral to dorsal, is also present. Juveniles and subadults show that synarcual calcification is relatively late compared to the calcification of other regions of the skeleton and proceeds from lateral to medial. Comparison with extinct taxa also indicates that there is a decrease in vertebral centrum involvement with the synarcual cartilage over the evolutionary history of the clade. Results from exploratory analyses of morphospace and taxonomy reveal that phylogeny explains part, but not all, of the data on the synarcual in Rajidae. There is evidence of individual and ontogenetic variation among all species of skates examined, however, phylogenetically informative variation prevails. Comparison with other batoids demonstrates a trend where the number of vertebral centra flanked by the synarcual cartilage decreases among more derived taxa indicating a high degree of convergent morphology among batoids with potential functional significance.
Technical considerations in in vivo thyroid studies

Radionuclide thyroid studies, although among the oldest of clinical nuclear medicine procedures, continue to show growth and change. In the 7 years since thryoid studies were last reviewed in the Seminars , there have been marked changes in the preferred ways of doing these studies. In the area of radiopharmaceuticals, 131 I remains a useful agent in selected circumstances, but 99m Tc-pertechnetate has become the agent of choice for imaging applications. Iodine-123 represents an exciting possibility for the future if problems in cost and radiopurity can be solved. New data on the dosimetry of the various agents allow for more rational choices among them, and useful guidelines can now be given for the use of these radiopharmaceuticals in problem areas such as pregnancy, nursing, and the pediatric age group. The scintillation camera with a pinhole collimator has become the instrument of choice for thyroid imaging, and the use of computers and the availability of systems for fluorescent scanning have added new possibilities for thyroid evaluation. Ancillary techniques such as ultrasound scanning also offer the possibility of improved diagnostic accuracy. These developments are reviewed in the context of clinical studies, together with a discussion of specific clinical applications and a brief look to the future.
Caution and probing in a macroeconomic model

Abstract This paper reports on the application of an adaptive (dual) control technique to a small macroeconometric model of the U.S. economy. Both monetary and fiscal policy variables are used in the model. The experiments find that probing and active learning will occur in small macroeconometric models but that unrealistically high terminal period penalties on state deviations are required before it appears.
Amphibian production in forested landscapes in relation to wetland hydroperiod: A case study of vernal pools and beaver ponds

Abstract Many amphibian species are plastic in their selection of breeding sites and use both short- and longer-hydroperiod wetlands. Understanding which wetland types are most important to amphibian production is critical for focusing conservation efforts. We compared reproduction of wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) and production of wood frog juveniles between seasonal (vernal pools) and semi-permanent (beaver-created ponds) wetlands in the central Adirondack region of the northeastern United States. In 65 seasonal wetlands and 37 semi-permanent wetlands over 3 years, densities of wood frog egg masses were similar, but seasonal wetlands contained 4× as many spotted salamander egg masses as did semi-permanent wetlands. For wood frogs, survival to metamorphosis and juvenile production were an order of magnitude higher in semi-permanent wetlands. Models of wood frog production linked to the climatic record predicted that, depending on annual variation in rainfall and survival to metamorphosis, semi-permanent wetlands may produce annually 1.2–23× the number of wood frogs that seasonal wetlands produce within the study area. Models incorporating variation in demographic traits throughout the range of wood frogs suggest that higher survival to metamorphosis in beaver ponds and higher clutch densities in vernal pools strongly influence metamorph production on a regional basis. Semi-permanent wetlands make major contributions to amphibian production in our region and may also be an important source of colonists to seasonal wetlands following periods of drought. Protection of wetlands along the landscape-level continuum of hydroperiod therefore may be critical for maintaining and restoring amphibian populations.
Splanchnic Artery Aneurysms

Splanchnic artery aneurysms were encountered in 45 patients. This experience and a comprehensive review of the literature since 1960 resulted in revision of many preexisting concepts concerning the pathogenesis and prognostic implications of these lesions. Most significant is that multiparity may result in medial degeneration with subsequent development of splenic artery aneurysms. A previously unrecognized association of renal artery fibromuscular disease and splenic artery aneurysms was documented. The established morbidity and mortality attributed to all aneurysms of the splanchnic arteries justifies prompt surgical treatment once their presence is known.
Commercial toxicology prediction systems: a regulatory perspective.

The use of commercial toxicity prediction systems in a regulatory setting must consider both the limitations and capabilities of the methods, as well as the ultimate use of the predictions, e.g. for testing prioritization, screening, or supporting regulatory decisions. Current systems are better suited to hazard identification (i.e. positive identification of activity-conferring features) than to ruling out hazard. Two recent examples (an EPA testing prioritization exercise for water disinfection byproducts and a regulatory action on 2,4,6-tribromophenol) illustrate issues involved in regulatory applications of SAR and commercial prediction systems. The challenge for the future will be to improve technologies for prediction within the constraints of available data, make optimal use of new test data, and better integrate elements of quantitative modeling (QSAR), empirical association, and biological and chemical mechanisms towards the goal of toxicity prediction.
Resonance transmission or absorption in deep gratings explained by magnetic polaritons

Resonance transmission or absorption has been observed in metallic deep gratings and previously characterized as coupled surface plasmon polaritons or Fabry–Perot-like resonances. This letter provides a quantitative explanation of this phenomenon by means of localized magnetic polaritons. Rigorous coupled-wave analysis is used to predict the spectral transmittance and absorptance of subwavelength gratings. The resonance condition is compared with that predicted by the LC circuit model. Some geometric effects that cannot be explained by previous models can be well understood in terms of magnetic polaritons. The insight gained from this study may facilitate future design and applications of subwavelength periodic structures.
Early recovery of a multi-lingual speaker with aphasia using Cantonese and English

This study reports a systematic monitoring of recovery from bilingual aphasia in a 75-year-old high-functioning multi-lingual female speaker of Cantonese and English, S1. She received six monthly evaluations after stroke by means of the Western Aphasia Battery and its Cantonese version (to monitor linguistic recovery and change of aphasia syndrome), cognitive linguistic quick test (to monitor cognitive recovery), and the main concept analysis (to assess the changes of narrative skills). Results indicated a non-parallel linguistic recovery, with a better improvement in her native L1 (Cantonese) than English. Since S1 demonstrated a change of using Cantonese dominantly post stroke, the results illustrated that a higher daily use of one language post-morbidly would lead to better post-morbid proficiency profile at the early recovery period. S1's changes in cognitive functions and narrative skills were also consistent with her linguistic improvement.
Biomembrane Permeation of Nicotine: Mechanistic Studies with Porcine Mucosae and Skin

In the present study, the permeation and partitioning of nicotine as a function of pH was investigated with various regions of skin and absorptive mucosae that were freshly excised from domestic pigs. As an ionizable compound (pKa values of 3.04 and 7.84), nicotine in solutions of different pH values provides a model for determining the influence of the charge status of a molecule on permeation. The permeation of nicotine across porcine mucosae and skin followed zero-order kinetics. The rate of permeation was dependent on donor solution pH and increased exponentially as the pH increased. With an exception of the nasal mucosa, which showed similar permeabilities for all species of nicotine, the permeability of nicotine across various skin and mucosal specimens was significantly higher (p < 0.001) for the un-ionized species (NN) than for the ionized species (NNH+, NH+NH+). It was also seen that un-ionized nicotine molecules were more permeable through absorptive mucosae (nasal, buccal, sublingual, and gingival) than through skin (abdominal, dorsal, thigh, and ear pinna). Partition studies were performed and the results further confirmed that biomembrane permeation of nicotine follows the pH-partition theory.
Telomerase activity in mouse myeloid leukemic cells and in cells from normal hematopoietic systems.

The telomeric repeat amplification protocol (TRAP) assay was used to measure telomerase activity in radiation-induced mouse myeloid leukemic (ML) cells and in several populations of normal cells. A detectable level of telomerase activity was found in normal hematopoietic tissues, i.e., bone marrow (BM) cells, day 9 colony-forming unit spleen (CFU-S) colonies, peripheral blood (PB) lymphocytes, and spleen. The level of telomerase activity in normal BM cells was used as a background level. Nine of the 12 cases of ML had higher levels of activity than that of the normal BM cells and therefore they were scored as ML with positive telomerase. The other three cases were considered as ML with negative telomerase because the levels of the enzyme were equivalent to that of normal BM cells. The data indicate that cellular differentiation may suppress telomerase activity in mouse ML cells. In summary, the results suggest that the CBA/Ca mouse model should be a useful animal system for future studies on the assessment of telomerase activity in both malignant and normal hematopoietic cells.
Optical engineering and characterization of the internal electric field of CdZnTe radiation detectors

A new method of engineering the internal electric field of CdZnTe (CZT) radiation detectors will be introduced. The internal electric field distribution within a CZT detector is engineered via an IR beam with a special photon energy and characterized by a separate polarized optical transmission profile beam utilizing the Pockels electro- optic effect. A theoretical model and calculation will be presented to understand the internal electric field engineering we have performed in our work. 2D images reflecting the internal electrical field intensity changes will be shown and the application of this field engineering method to improve the radiation detectors will be discussed.
Ba3AlO4H: Synthesis and Structure of a New Hydrogen-Stabilized Phase☆

Abstract The title compound and its deuteride were synthesized in high yield by sintering appropriate mixtures of BaH2(BaD2), BaO and Al2O3in welded Ta containers at 1100°C under a hydrogen (deuterium) pressure of 600–700 torr. The structure was determined by a combination of single crystal X-ray and time-of-flight powder neutron diffraction means (orthorhombicPnma,Z=4,a=10.4911(9),b=8.1518(7),c=7.2399(6) A for the deuteride). The compound contains nominal Ba2+cations, AlO5−4complex anions and H−(D−) anions. The hydride is bound in a strongly distorted barium octahedron while the tetrahedral AlO5−4anion is surrounded by eleven barium atoms in a peculiar polyhedral configuration. The HBa6octahedra are linked together by corner-sharing to form a three dimension framework with large voids defined by eight of the HBa6octahedra that are occupied by the tetrahedral AlO5−4anions. The structure is closely related in a hierarchical way to that of orthorhombic inverse perovskitic Ba3GeO.
Gender Role Ideologies and Marriage Promotion: State Policy Choices and Suggestions for Improvement

The 1996 Personal Responsibility and Work Opportunities Reconciliation Act (PRWORA) lists marriage as one of the major strategies for reducing welfare dependency among clients of the Temporary Assistance for Needy Families (TANF) Program along with work requirements and time limits. President George W. Bush has allocated over $240 million to the individual states to create programs to promote and sustain marriages, with specific attention given to encouraging marriage among the low-income, welfare-reliant population. We suggest that this policy is based upon a specific gender ideology that seems to ignore the reality of the lives of poor women with children and may be, as some critics suggest, an attempt at “legislating patriarchy.” In this work, we trace the social changes that shaped this ideology, present the options the states have taken to encourage marriage, discuss flaws in the philosophy and implementation of these policies, and provide suggestions for improving program design.
Comparative Views of Adult Neurogenesis

Traditional views maintain that the generation of neurons within the mammalian brain is restricted to a discrete developmental period. This perspective has undergone significant revision during the later half of this century, culminating recently with the demonstration of neurogenesis in the brains of adult primates, including humans. Although it is becoming increasingly clear that adult neurogenesis represents an important mode of structural modification for the adult brain, its functional significance has not been determined. The production and survival of new neurons in the adult mammalian brain is regulated by both experiential and neuroendocrine factors, suggesting that adult-generated neurons may serve as a substrate by which these cues influence normal brain function. This article reviews significant advances that have led to the discovery of neurogenesis in adult mammals and examines comparative data suggesting that adult neurogenesis may play a role in certain forms of learning. Neural activity a...