cssi/SciSciGPT-SciSciNet huggingface dataset:
SEDIMENTOLOGY AND CARBON ISOTOPE (δ13C) STRATIGRAPHY OF SILURIAN–DEVONIAN BOUNDARY INTERVAL STRATA, APPALACHIAN BASIN (PENNSYLVANIA, USA)

Silurian–Devonian boundary interval strata deposited during the expansion of land plants record a major perturbation of the carbon cycle, the global Klonk Event, one of the largest carbon isotope excursions during the Phanerozoic. In the Appalachian Basin, these marine strata record the regional buildup to the Acadian Orogeny. This study reports new sedimentologic, paleontologic, ichnologic, and carbon isotope data from an exceptional quarry exposure in central Pennsylvania, USA, a historically understudied area between better-documented outcrops >500 km away to the southwest (West Virginia, Virginia, Maryland) and northeast (New York). Facies spanning the continuous 113-m thick outcrop are dominantly carbonate and fine-grained siliciclastic strata interpreted as being deposited in supratidal through subtidal environments, including oxygen-limited environments below storm wave base. They record parts of three transgressive-regressive cycles, in the (1) upper Silurian Tonoloway Formation, (2) upper Silurian–Lower Devonian Keyser Formation through lower Mandata Member of the Old Port Formation, and (3) Lower Devonian Mandata through Ridgeley Members of the Old Port Formation. Micrite matrix δ13Ccarb analyses exhibit a large, positive δ 13Ccarb excursion (>5‰ amplitude). Outcrops of this interval in the Appalachian Basin occur in two belts, between which correlation has been historically challenging. The regional correlation presented herein is based on carbon-isotope trends and is more consistent with published conodont biostratigraphy and volcanic ash ages, an improvement over published correlations based on lithostratigraphy. Transgressive-regressive trends at the central Pennsylvania study site are not consistent with regional trends, indicating that local controls (tectonics, sediment supply) rather than global (eustasy) dominated depositional patterns in the Silurian–Devonian boundary interval in the Appalachian Basin.
Identification of Lenalidomide Sensitivity and Resistance Mechanisms in Non-Del(5q) Myelodysplastic Syndromes

Whereas lenalidomide is an effective therapy for del(5q) MDS patients, a minority of non-del(5q) MDS patients achieve hematologic improvement with lenalidomide. We used computational biology modeling and digital drug simulation to examine genomic data from 56 non-del(5q) MDS patients treated with lenalidomide, and then matched treatment response with molecular pathways. The computer inferred genomic abnormalities associating with lenalidomide treatment response in non-del(5q) MDS to include trisomy 8, del(20q), or RUNX1 loss of function mutations. Genomic abnormalities associating with lenalidomide resistance in non-del(5q) MDS patients included mutations in SF3B1, TET2, WNT3A amplification, MCL1 amplification, and/or PSEN2 amplification. These results may inform protocols for determining appropriateness of lenalidomide in non-del(5q) MDS.
Rethinking Environmental Carcinogenesis

The 2010 report of the President's Cancer Panel concluded that the burden of cancer from chemical exposures is substantial, while the programs for testing and regulation of carcinogens remain inadequate. New research on the role of early life exposures and the ability of chemicals to act via multiple biological pathways, including immunosuppression, inflammation, and endocrine disruption as well as mutagenesis, further supports the potential for chemicals and chemical mixtures to influence disease. Epidemiologic observations, such as higher leukemia incidence in children living near roadways and industrial sources of air pollution, and new in vitro technologies that decode carcinogenesis at the molecular level, illustrate the diverse evidence that primary prevention of some cancers may be achieved by reducing harmful chemical exposures. The path forward requires cross-disciplinary approaches, increased environmental research investment, system-wide collaboration to develop safer economic alternatives, and community engagement to support evidence-informed action. Engagement by cancer researchers to integrate environmental risk factors into prevention initiatives holds tremendous promise for reducing the rates of disease.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."
A Rare Case of Disseminated Coccidioidomycosis Presenting as Brachial Plexopathy.

Coccidioidomycosis, a fungal infection caused by inhaling spores of Coccidioides immitis/posadasii, is endemic to the southwestern states of the United States, Northern Mexico and some parts of Central and South America. It is primarily a pulmonary infection with less than 0.5% of symptomatic cases showing dissemination. Skin, lymph nodes and bone are the commonest sites. Neurological involvement is rare and commonly presents as strokes, abscesses or meningoencephalitis. We present the case of a previously healthy 23-year-old African American male, presented with a four-month history of progressive right upper extremity weakness that initially started with right shoulder pain followed by worsening weakness and loss of muscle mass. Electromyography (EMG) demonstrated right brachial plexopathy with moderate-to-severe active denervation changes. MRI cervical spine revealed a 9-cm contrast enhancing extradural mass extending through the neural foramen from C4-T1 roots and forming a 4-cm right apical lung mass subsequently seen on MRI of the brachial plexus. All trunks, divisions and cords were thickened, hyperintense and showed contrast enhancement on MRI. Neuromuscular ultrasound (NUS) demonstrated enlargement of peripheral nerves. Differentials prior to biopsy of the mass ranged from neurofibromas to pancoast lung tumors. Coccidioidomycosis did not figure on the initial list of differentials. Patient underwent subsequent biopsy of the extradural and lung masses that showed coccidiodes. Serum coccidioides antibody titers were elevated. The patient was treated with high-dose intravenous fluconazole and aggressive mass debridement. His weakness improved on four months follow-up evaluation with significant resolution of EMG abnormalities and decreased swelling on NUS.
Within- and between-language competition in adult second language learners: implications for language proficiency

Second language (L2) learners must not only acquire L2 knowledge (i.e. vocabulary and grammar), but they must also rapidly access this knowledge. In monolinguals, efficient spoken word recognition ...
Waterway Engineering Applications of Automatic Identification System Data along the Mississippi River and at Lock Structures

Abstract The USACE, St. Louis District, is responsible for maintaining navigation channels along with multiple lock and dam structures on the Mississippi River, a vital inland waterway that carries...
Antiviral CD19+CD27+ Memory B Cells Are Associated with Protection from Recurrent Asymptomatic Ocular Herpes Infection

ABSTRACT Reactivation of herpes simplex virus 1 (HSV-1) from latently infected neurons of the trigeminal ganglia (TG) leads to blinding recurrent herpetic disease in symptomatic (SYMP) individuals. Although the role of T cells in herpes immunity seen in asymptomatic (ASYMP) individuals is heavily explored, the role of B cells is less investigated. In the present study, we evaluated whether B cells are associated with protective immunity against recurrent ocular herpes. The frequencies of circulating HSV-specific memory B cells and of memory follicular helper T cells (CD4+ Tfh cells), that help B cells produce antibodies, were compared between HSV-1 infected SYMP and ASYMP individuals. The levels of IgG/IgA and neutralizing antibodies were compared in SYMP and ASYMP individuals. We found that: (i) the ASYMP individuals had increased frequencies of HSV-specific CD19+CD27+ memory B cells; and (ii) high frequencies of HSV-specific switched IgG+CD19+CD27+ memory B cells detected in ASYMP individuals were directly proportional to high frequencies of CD45R0+CXCR5+CD4+ memory Tfh cells. However, no differences were detected in the level of HSV-specific IgG/IgA antibodies in SYMP and ASYMP individuals. Using the UV-B-induced HSV-1 reactivation mouse model, we found increased frequencies of HSV-specific antibody-secreting plasma HSV-1 gD+CD138+ B cells within the TG and circulation of ASYMP mice compared to SYMP mice. In contrast, no significant differences in the frequencies of B cells were found in the cornea, spleen, and bone-marrow. Our findings suggest that circulating antibody-producing HSV-specific memory B cells recruited locally to the TG may contribute to protection from symptomatic recurrent ocular herpes. IMPORTANCE Reactivation of herpes simplex virus 1 (HSV-1) from latently infected neurons of the trigeminal ganglia (TG) leads to blinding recurrent herpetic disease in symptomatic (SYMP) individuals. Although the role of T cells in herpes immunity against blinding recurrent herpetic disease is heavily explored, the role of B cells is less investigated. In the present study, we found that in both asymptomatic (ASYMP) individuals and ASYMP mice there was increased frequencies of HSV-specific memory B cells that were directly proportional to high frequencies of memory Tfh cells. Moreover, following UV-B induce reactivation, we found increased frequencies of HSV-specific antibody-secreting plasma B cells within the TG and circulation of ASYMP mice, compared to SYMP mice. Our findings suggest that circulating antibody-producing HSV-specific memory B cells recruited locally to the TG may contribute to protection from recurrent ocular herpes.
From The Wealth of Nations to Populorum Progressio (On the Development of Peoples): Wealth and Development from the Perspective of the Catholic Social Thought Tradition

Catholic social thought (CST) looks at economic development from the broader framework of authentic human development. It is only by viewing both man's dignity and his social nature that we include the full nature of the human being. In CST wealth is understood based on its role in promoting authentic human development. Wealth is a gift from God, with humans participating in its creation, and its creation, distribution, and its use must be carried out in a manner that respects God's law (justice and charity). Furthermore, man should never place wealth above God or above humans. Those who control wealth have special responsibilities with regards to their use of it; thus the right of private property is always restricted by the social responsibility to use it towards the common good. The goal must be the development of the whole person and all people. Wealth is socially created and thus must be distributed, at least partially, among the entire community. Economic development needs to be grounded in social justice and its two co-principles, charity and justice. Grounding economic development in the authentic development of the person means placing the people of the poor countries at the center of their development drama, both as the leading actors and as the directors.
Compiling Joy Into Silicon: An Exercise in Applied Structural Operational Semantics

We present the highlights of an algorithm and correctness proof for compiling programs written in Joy, a simple parallel language, into delay-insensitive circuits. The proof relies heavily on techniques of structural operational semantics, many of which should generalize to similar settings.
Receding horizon sliding control for linear and nonlinear systems

Sliding mode control (SMC) is one of the few controller design methodologies that can be applied to highly nonlinear and uncertain systems. In most mechanical applications, a smoothed version of SMC that we call “sliding control” is employed to keep the system trajectories close to but not necessarily on a stable differential/difference manifold. In this paper, we propose an extension to the sliding control algorithm that includes a receding horizon approach. This allows the designer to incorporate information about future desired output trajectories as well as knowledge of future disturbances. In addition, it allows the designer to include bounds on the inputs and states of the system. We refer to this control methodology as receding horizon sliding control (RHSC) and evaluate its effectiveness using two example applications.
Signaling in Natural Immunity: Natural Killer Cells

ABSTRACT Natural killer (NK) cells are large granular lymphocytes noted both for their cytotoxic role in innate immunity and for their linking of the innate immune system to the adaptive immune system through cytokine secretion. In both of these roles, NK cells make use of their ability to recognize tumour- and virus-associated ligands. These cells are identified by their phenotype: NK cells express CD 16, the low-affinity Fc receptor (FcR) for IgG, but NK cells do not express T cell antigen receptors or the B cell-associated surface immunoglobulin (sIg). Unlike T cells or B cells, NK cells do not have a single type of receptor through which they recognize antigens. Rather, clonal subpopulations of NK cells differ in their expression of receptors that recognize a variety of ligands on target cells throughout the body. NK cell binding of these ligands initiates signaling cascades within the NK cell that control its response to the target. Thus, understanding these receptors, their signals, and the interactions of the signaling pathways is key to understanding NK cell function.
Interconnects for All-Spin Logic Using Automotion of Domain Walls

In this paper, an interconnect scheme based on automotion of domain walls (DWs) for all-spin logic (ASL) has been proposed. The proposed interconnect is analyzed using a comprehensive numerical model including an equivalent circuit for ASL operations, the 1-D Landau–Lifshitz–Gilbert equation for DW creation, reflection, and disappearance at the boundaries. Analytical expressions for DW transport along the wire are also presented. From the model, it is found that the reflection of the DW can be eliminated using a material with a high Gilbert damping coefficient at the end, the energy dissipation can be independent of the interconnect length, and DW displacement and energy dissipation can be further improved using a material with a low damping factor and saturation magnetization. Furthermore, the interconnect reliability is also studied by applying the thermal random noise analysis on the dynamics of DWs, and it is found that thermal fluctuations can have a significant impact on the interconnect performance; thus, the interconnect with a low Gilbert damping factor is desired to suppress the thermal noise effects.
The presence of primary cilia in cancer cells does not predict responsiveness to modulation of smoothened activity.

Primary cilia are microtubule-based organelles that regulate smoothened-dependent activation of the GLI transcription factors in canonical hedgehog signaling. In many cancers, primary cilia are markedly decreased or absent. The lack of primary cilia may inhibit or alter canonical hedgehog signaling and, thereby, interfere in the cellular responsive- ness to modulators of smoothened activity. Clinical trials of smoothened antagonists for cancer treatment have shown the best response in basal cell carcinomas, with limited response in other solid tumors. To determine whether the presence or absence of primary cilia in cancer cells will predict their responsiveness to modulation of smoothened activity, we compared the ability of an agonist and/or inhibitor of smoothened (SAG and SANT1, respectively) to modulate GLI-mediated transcription, as measured by GLI1 mRNA level or GLI-luciferase reporter activity, in non-cancer cells with primary cilia (ovarian surface epithelial cells and breast fibroblasts), in cancer cells that cannot assemble primary cilia (MCF7, MDA-MB-231 cell lines), and in cancer cells with primary cilia (SKOV3, PANC1 cell lines). As expected, SAG and SANT1 resulted in appropriate modulation of GLI tran- scriptional activity in ciliated non-cancer cells, and failed to modulate GLI transcriptional activity in cancer cells without primary cilia. However, there was also no modulation of GLI transcriptional activity in either ciliated cancer cell line. SAG treatment of SKOV3 induced localization of smoothened to primary cilia, as assessed by immunofluorescence, even though there was no increase in GLI transcriptional activity, suggesting a defect in activation of SMO in the primary cilia or in steps later in the hedgehog pathway. In contrast to SKOV3, SAG treatment of PANC1 did not cause the localization of smoothened to primary cilia. Our data demonstrate that the presence of primary cilia in the cancer epithelial cells lines tested does not indicate their responsiveness to smoothened activation or inhibition.
THE JOINT DISTRIBUTION OF BIVARIATE EXPONENTIAL UNDER LINEARLY RELATED MODEL

In this paper, fundamental results of the joint distribution of the bivariate exponential distributions are established. The positive support multivariate distribution theory is important in reliability and survival analysis, and we applied it to the case where more than one failure or survival is observed in a given study. Usually, the multivariate distribution is restricted to those with marginal distributions of a specified and familiar lifetime family. The family of exponential distribution contains the absolutely continuous and discrete case models with a nonzero probability on a set of measure zero. Examples are given, and estimators are developed and applied to simulated data. Our findings generalize substantially known results in the literature, provide flexible and novel approach for modeling related events that can occur simultaneously from one based event.
Interprofessional collaboration milestones: advocating for common assessment criteria in graduate medical education

Milestone-based assessments of resident physicians inform critical decisions regarding resident competence and advancement. Thus, it is essential that milestone evaluations are based upon strong validity evidence and that consistent evaluation criteria are used across residency programs. A common approach to assessment of interprofessional collaboration milestones is particularly important since standardized measures of individual resident competence in interprofessional collaboration have not been established. We propose that assessments of interprofessional collaboration in graduate medical education meet common criteria, namely, these assessments should: 1) measure competency of an individual resident, 2) occur in the context of an interprofessional team, 3) be ascertained via direct observation of the resident, 4) be performed in a real-world clinical practice setting (such as a hospital ward, outpatient clinic, or operating room). We present the evidence-based rationale for these criteria and cite examples of published assessment instruments that fulfill one or more of the criteria, however further research is needed to ensure fidelity of assessments. The proposed criteria may assist residency educators as they endeavor to provide robust and consistent assessments of interprofessional collaboration milestones.
Learning the Nonlinear Geometry of High-Dimensional Data: Models and Algorithms

Modern information processing relies on the axiom that high-dimensional data lie near low-dimensional geometric structures. This paper revisits the problem of data-driven learning of these geometric structures and puts forth two new nonlinear geometric models for data describing “related” objects/phenomena. The first one of these models straddles the two extremes of the subspace model and the union-of-subspaces model, and is termed the metric-constrained union-of-subspaces (MC-UoS) model. The second one of these models—suited for data drawn from a mixture of nonlinear manifolds—generalizes the kernel subspace model, and is termed the metric-constrained kernel union-of-subspaces (MC-KUoS) model. The main contributions of this paper in this regard include the following. First, it motivates and formalizes the problems of MC-UoS and MC-KUoS learning. Second, it presents algorithms that efficiently learn an MC-UoS or an MC-KUoS underlying data of interest. Third, it extends these algorithms to the case when parts of the data are missing. Last, but not least, it reports the outcomes of a series of numerical experiments involving both synthetic and real data that demonstrate the superiority of the proposed geometric models and learning algorithms over existing approaches in the literature. These experiments also help clarify the connections between this work and the literature on (subspace and kernel $k$ -means) clustering.
Silencing of epithelial CXCL12 expression by DNA hypermethylation promotes colonic carcinoma metastasis.

Cellular metastasis is the most detrimental step in carcinoma disease progression, yet the mechanisms that regulate this process are poorly understood. CXCL12 and its receptor CXCR4 are co-expressed in several tissues and cell types throughout the body and play essential roles in development. Disruption of either gene causes embryonic lethality due to similar defects. Post-natally, CXCL12 signaling has a wide range of effects on CXCR4-expressing cells, including the directed migration of leukocytes, lymphocytes and hematopoietic stem cells. Recently, this signaling axis has also been described as an important regulator of directed carcinoma cell metastasis. We show herein that while CXCR4 expression remains consistent, constitutive colonic epithelial expression of CXCL12 is silenced by DNA hypermethylation in primary colorectal carcinomas as well as colorectal carcinoma-derived cell lines. Inhibition of DNA methyltransferase (Dnmt) enzymes with 5-aza-2′-deoxycytidine or genetic ablation of both Dnmt1 and Dnmt3b prevented promoter methylation and restored CXCL12 expression. Re-expression of functional, endogenous CXCL12 in colorectal carcinoma cells dramatically reduced metastatic tumor formation in mice, as well as foci formation in soft agar. Decreased metastasis was correlated with increased caspase activity in cells re-expressing CXCL12. These data constitute the unique observation that silencing CXCL12 within colonic carcinoma cells greatly enhances their metastatic potential.
Conversion of dimolybdenum tetraacetate to Mo2Cl4(Ph2Ppy)2 and Mo2(O2CCH3)2(Ph2Ppy)2Cl2 [Ph2Ppy=2-(diphenylphosphino)pyridine]

Abstract Dimolybdenum tetraacetate reacts with (CH3)3SiCl and Ph2Ppy [2-(diphenylphosphino)pyridine] to give green Mo2Cl4(Ph2Ppy) 2 which was too insoluble to crystallize or characterize. The reaction of Mo2Cl4(Ph2Ppy)2 with acetic acid has been investigated. Mo2(O2CCH3)4 and Mo2(O2CCH3)2(Ph2Ppy)2Cl2 are the products resulting from total and partial ligand substitution reactions. The molecular structure of Mo2(O2CCH3)2(Ph2Ppy)2Cl2 has been investigated by X-ray crystallography. The crystallographic data are as follows: triclinic space group P 1 , a = 10.789(2), b = 12.414 (3), c = 9.888(2) A, α = 110.48(2)°, β = 113.86(2)°, γ = 67.36(3)°, V= 1088(1) A3 and Z = 1. The molecule has two trans bridging acetate groups, two trans 2-diphenylphosphinopyridine ligands arranged in a head-to-tail fashion, and two axial chlorine atoms. The length of the quadruple bond between the molybdenum atoms is 2.1900(3) A, which makes it the longest one known.
Isolation and purification of large quantities of DNA replication intermediates by pH step alkaline elution.

The alkaline elution technique has been modified to be used in the isolation of DNA replication intermediates and in the study of the process of DNA replication. In this procedure pulse labeled CHO cells are layered onto a membrane filter, lysed with detergent, and the nascent DNA eluted in step-wise fashion with tetrapropylammonium hydroxide at pH 11.0, 11.3, 11.5 and 12.1. Alkaline sucrose sedimentation of the eluted DNA shows that the pH 11.0 material consists of < 9S fragments consistant with those described by Okazaki and others. DNA eluting at pH 11.3 has a molecular weight of 8–12 million daltons, DNA which elutes at pH 11.5 sediments with a molecular weight of 20–30 million daltons. Two independent lines of evidence suggest that the pH 11.3 material includes DNA sequences synthesized at replicon origins. (1) Exposure of cells to low doses of X-ray prior to pulse labeling reduces the pH 11.3 fraction by 40–50% while there is little change in the other fractions. (2) Synchronization of cells by inhibiting DNA synthesis with FdU, followed by a 2 min pulse label, yields approximately 50% of the incorporated 3H-thymidine in the pH 11.3 fraction. The pH step elution technique has the following advantages: 1. Intermediates of high specific activity can be isolated from 106 cells per filter; 2. By lysing cells on a filter, proteins, nucleases, and other cellular materials are eliminated; 3. DNA in the lysate is never handled, thus eliminating shearing; 4. Eluted DNA may be instantaneously neutralized by collecting into a buffer to protect it from alkaline degradation.
Methylamine oxidation in a flow reactor: Mechanism and modeling

Abstract The high-temperature oxidation chemistry of methylamine (CH3NH2) has been investigated by elucidating the major reaction paths under flow reactor conditions. A comprehensive detailed chemical-kinetic mechanism is proposed, which is comprised of 350 elementary reactions and 65 reactive species. A set of pyrolysis and oxidation reactions of CH3NH2, combined with the literature HCON reaction chemistry, constitute the proposed mechanism. In addition, the reactions of H-abstraction from both the C- and N-atom centers of CH3NH2, have been incorporated into the mechanism. Good agreement between model predictions and experimental data is obtained over fuel-to-oxygen equivalence ratios ranging from 0.1 to 1.7, for 600–1400 K temperature range, and for subatmospheric (0.01 atm) as well as for atmospheric flow conditions. A reaction path analysis was conducted using the integral averaged reaction rates, and the major reaction pathways were identified. A first-order sensitivity analysis for species CH3NH2, NO, and HCN was performed and the results are compared with the reaction-path analysis.
Medical practices display power law behaviors similar to spoken languages.

Medical care commonly involves the apprehension of complex patterns of patient derangements to which the practitioner responds with patterns of interventions, as opposed to single therapeutic maneuvers. This complexity renders the objective assessment of practice patterns using conventional statistical approaches difficult. Combinatorial approaches drawn from symbolic dynamics are used to encode the observed patterns of patient derangement and associated practitioner response patterns as sequences of symbols. Concatenating each patient derangement symbol with the contemporaneous practitioner response symbol creates “words” encoding the simultaneous patient derangement and provider response patterns and yields an observed vocabulary with quantifiable statistical characteristics. A fundamental observation in many natural languages is the existence of a power law relationship between the rank order of word usage and the absolute frequency with which particular words are uttered. We show that population level patterns of patient derangement: practitioner intervention word usage in two entirely unrelated domains of medical care display power law relationships similar to those of natural languages, and that–in one of these domains–power law behavior at the population level reflects power law behavior at the level of individual practitioners. Our results suggest that patterns of medical care can be approached using quantitative linguistic techniques, a finding that has implications for the assessment of expertise, machine learning identification of optimal practices, and construction of bedside decision support tools.
Some econometric considerations in studying regional demand patterns in the United States

Manhertz H. G. (1970) Some econometric considerations in studying regional demand patterns in the United States, Reg. Studies 4, 107–115. Regional differences in demand may be largely attributed to the degree of spatial heterogeneity which is characteristic of a given geographic area. To the extent that the pattern of demand for a region or contiguous regions can be unique, national demand analysis should be carried out within the disaggregative framework of regional demand functions. The model developed in this article involves a basic demand function explaining quantity demanded in terms of disposable income, price and an urbanization index for each of nine regions in the continental United States. Alternative formulations are developed for each region in order to examine the probable existence of simultaneity and multicollinearity among the variables. The model is evaluated in terms of the demand for processed vegetables and shows that most of the interregional variations in demand may be attributed to...
Fit of Item Response Theory Models: A Survey of Data from Several Operational Tests

Standard 3.9 of the Standards for Educational and Psychological Testing (American Educational Research Association, American Psychological Association, & National Council for Measurement in Education, 1999) demands evidence of model fit when an item response theory (IRT) model is used to make inferences from a data set. We applied two recently suggested methods for assessing goodness of fit of IRT models—generalized residual analysis (Haberman, 2009) and residual analysis for assessing item fit (Bock & Haberman, 2009)—to several operational data sets. We assessed the practical significance of misfit whenever possible. This report summarizes our findings. Though evidence of misfit of the IRT model was found for all the data sets, the misfit was not always practically significant.
Formation and Evaluation of Protective Layer over Magnesium Melt Under CO 2 /Air Mixtures

Molten magnesium oxidizes rapidly when exposed to air causing melt loss and handling difficulties. The use of certain additive gases to form a protective MgO layer over a magnesium melt has been proposed. The oxidation behavior of molten magnesium in air that contains various concentrations of CO2 was investigated, including the kinetics of the oxide layer growth. Experiments were performed using a thermogravimetric analysis unit in the temperature range of 943 K to 1043 K (670 °C to 770 °C). Results showed that a thin, coherent, and protective MgO-C layer was formed under the test conditions. The thicknesses of this layer formed under CO2/air ranged from 500 nm to 12 μm. Rate parameters were calculated and a model for the process was developed. The morphology and composition of the surface films were studied using SEM and EDS.
SUBURBAN DOWNTOWNS AND THE TRANSFORMATION OF METROPOLITAN ATLANTA'S BUSINESS LANDSCAPE

The suburbanization of economic activity reached massive proportions in recent years and contributed significantly to the spatial restructuring of the American metropolis. One of the most important geographic expressions in the emergence of the outer suburban city is the clustering of high-order activities in new metropolitan-level urban centers. These complexes are here defined as suburban downtowns, and their rapid evolution since the 1960s is traced through a number of developmental stages. Two of metropolitan Atlanta's suburban downtowns, which -ank among the largest in the United States, are highlighted in case studies in order to demonstrate the still-evolving dynamics that shape the functioning and internal structuring of these first-order activity complexes.
Human Milk Macrophages Generate More Superoxide Anion Than Monocytes After Stimulation With Unopsonized Zymosan

Human Milk Macrophages Generate More Superoxide Anion Than Monocytes After Stimulation With Unopsonized Zymosan
Inflammation and cardiovascular complications in chronic kidney disease

Cardiovascular disease is a leading cause of morbidity and mortality in patients with chronic kidney disease (CKD), accounting for 50% of deaths of patients on dialysis, even young adults. The etiology of accelerated cardiovascular disease in these patients is likely multifactorial. Although patients with CKD demonstrate a high prevalence of traditional risk factors for cardiovascular disease, these risk factors alone cannot explain the high burden of cardiovascular disease in this patient population. One of several uremia-related risk factors thought to contribute to disease progression is low-grade systemic inflammation. This review summarizes the current literature on the role of inflammation in promoting cardiovascular disease in this patient population as well as potential therapies to address this non-traditional risk factor.
Changes in sexual risk behavior as young men transition to adulthood.

CONTEXT: Understanding how young men’s sexual risk behaviors change during the transition from adolescence to early adulthood is important for the design and evaluation of effective strategies to reduce the transmission of HIV and other STDs. METHODS: Data from three waves of the National Survey of Adolescent Males (1988, 1991 and 1995) were used to categorize 1,880 respondents into clusters according to sexual risk behaviors. Univariate and bivariate analyses were conducted to assess associations between clusters and rates of self-reported STD diagnoses and positive chlamydia tests. RESULTS: Two dimensions of sexual risk-taking defined the clusters: partner characteristics and condom use. More than 50% of men remained in low-risk groups over time. In the first two waves, 24–32% of men reported engaging in high-risk behaviors (risky partners, condom nonuse); these behaviors were associated with elevated levels of STD outcomes. Nearly 40% of men who entered a high-risk group in the first two waves transitioned to a lower risk group by the third wave. Nine percent of men either engaged in increasingly risky behaviors or maintained membership in high-risk groups; elevated STD rates characterized both trajectories. Low condom use combined with having multiple partners during adolescence was associated with elevated STD rates in the year preceding the third wave; high condom use coupled with having risky partners was not. CONCLUSIONS: The prominence of low-risk behaviors over time suggests that most young men avoid sexual risk-taking. Effective strategies to reduce HIV and STD risk in young men must simultaneously address multiple dimensions of sexual behavior.
Photoperiodicity in the male albino laboratory rat

Animals inhabiting areas where there are drastic changes in the environment often reproduce only during limited time periods to ensure that young are raised in optimal environmental conditions. The lack of a well defined breeding season in many domesticated animals, presumably because the selective pressures for seasonal breeding have been minimized, suggests that the neuroendocrine events controlling seasonal cyclicity have been bred out of these animals. Little is known about the underlying neuroendocrine changes which may occur during the evolution of a species from a seasonal to a nonseasonal breeder. Whereas the changing photoperiod is the primary environmental cue which initiates and/or terminates the reproductive season in many animals, this is not so in the albino rat Rattus norvegicus, a model nonseasonal breeder. Nevertheless, daylength can influence various reproductive parameters in laboratory rats, suggesting that some of the neuroendocrine components that controlled seasonal breeding previously are still extant in this species. To test this hypothesis, we investigated the effect of daylength on the responsiveness of the neuroendocrine--gonadal axis to the negative-feedback effects of testosterone. This paradigm was chosen because of the important role played by photic-induced changes in steroid feedback sensitivity in the control of seasonal reproduction. We report here that although daylength has very little effect on neuroendocrine--gonadal function in the intact male laboratory rat, it seems that some component(s) of a photoperiodic system involving the pineal gland has been preserved.
Observations of a California Current Jet Meandering off the Continental Shelf into a Deep Ocean Region

During early August 2006, a series of meteorological and near surface oceanographic measurements (-0-200 m) were conducted from R/V Mt. Mitchell in an ocean region in the northeast Pacific, near 46degN, 126deg W, west of the North America continental shelf break, and in 2000 m deep water. The test region was roughly 20 nmi west of the main path of the California Current, however, observations of a jet meandering off the California Current and intruding into the deep water test region were captured in both in situ measurements from the R/V and remote satellite observations of the ocean surface. The horizontal boundaries of the jet intrusion in the test region are apparent in both in situ and satellite remote sensed temperature measurements as well as in ocean currents measured by ADCP and Lagrangian style surface drifters. Temperature and salinity profiles show waters associated with the jet are significantly cooler and slightly fresher than the ambient water in the test region. After initial observations of the intruding jet, measurements in the test region continued for the duration of seven days. Winds were initially relatively calm, in the 5-12 knot range, but after about three days, winds suddenly increased to over 20 knots, and high winds (NNW) persisted for three days. A corresponding increase in near surface, wind driven circulation was observed, moving approximately 90 degrees to the right of the wind direction. Eventually, wind driven currents dominated near surface circulation across the test region and the presence of the jet boundaries became less evident in CTD profiles collected over transects that cross in and out of the initial jet boundaries, after the wind speed increase. These results show the water in the test region gradually transitioning back to a horizontally homogeneous state as a result of wind induced mixing of the jet water and ambient water in the surrounding region. Detailed observations of the initial characteristics of the California Current jet intrusion into the deep water test region are presented along with the observations of the jet waters mixing with the local wind driven currents.
Vertical transport and photochemistry in the terrestrial mesosphere and lower thermosphere (50–120 km)

The coupled effects of kinetics, solar cycle flux variations and vertical transport on the distribution of long-lived hydrogen-carbon-oxygen compounds in the terrestrial mesosphere and lower thermosphere are studied using a one-dimensional aeronomy model. The calculations account for the important chemical reactions and use rocket measurements of the solar flux at solar minimum and maximum. Photodissociation rates appropriate for the mesosphere are determined with a spherical shell atmosphere formalism; detailed corrections for the O_2 Schumann-Runge bands and the temperature dependence of the CO_2 cross sections are used. Then an eddy diffusion profile is derived which gives agreement with the Aladdin 74 mass spectral measurements of atomic O, O_2, CO_2, and Ar in the lower thermosphere and observations of the O_3 minimum at ∼80 km. The 115 GHz CO radio emission line computed for the CO mixing ratio profile predicted with the new eddy diffusion profile compares well with recent observations of W. J. Wilson. Differences between the calculated CO mixing ratio profile and previous theoretical and observational determinations are discussed. Our derived eddy diffusion profile has a sudden decrease at 92 km which is necessary to produce the atomic O peak at 98 km that appears in the Aladdin 74 measurements. This stagnant region apparently is a recurrent or persistent feature of the upper atmosphere since an atomic O peak around 98 km has been seen by different techniques in different seasons over several years. Slow eddy diffusion in the lower thermosphere through the homopause was also the conclusion of earlier Ar/N_2 rocket measurements studies. The analytic approach of this paper could be used in the future to monitor variations in middle atmosphere dynamics, if regularly conducted simultaneous observations of various groups of species were available.
Red cell maturation: loss of a reticulocyte-specific membrane protein.

Abstract A protein present in red cell ghost membranes from reticulocyterich blood disappears from the membrane in vivo as the reticulocytes mature. This protein, with an estimated molecular weight of 33,000, is not present in mature circulating red blood cells. It is not associated with the ribosomes present in the reticulocyte.
Hemodynamic correlates of baroreflex impairment of heart rate in experimental canine heart failure.

The arterial baroreflex has been shown to be depressed in both clinical and experimental heart failure. The mechanism and significance of this depression remains controversial. Part of the change may reside in the baroreceptor as well as in the target organ. Previous studies in this laboratory have shown that there is no central depression of the baroreflex in anesthetized dogs. The present study was undertaken to determine the relationship between the change in baroreflex sensitivity (BRS) and the impairment of various hemodynamic parameters during the development of chronic heart failure in conscious dogs (n=15). The animals were instrumented to record pressures and derivatives in the left atrium, aorta and the left ventricle. Heart failure was achieved by rapid left ventricular pacing (250 bpm) until the development of clinical signs. BRS was determined by correlating systolic arterial blood pressure and pulse interval during bolus injections of nitroglycerin and phenylephrine. Data were analyzed by correlating the changes in BRS (n=90) with respect to changes in each parameter. No or a weak correlation was found between the changes in the baroreflex and parameters of systolic function or time of pacing. A stronger correlation was found between BRS and parameters of preload such as left ventricular enddiastolic pressure and left atrial pressure (p<0.001). In general, the bradycardia responses were depressed less than the tachycardia responses. The correlation between BRS and left atrial or left ventricular end diastolic pressure is consistent with the view that augmented input from cardiac receptors may contribute to the depressed baroreflex function in heart failure. These data also suggest that the sympathetic limb of baroreflex control of heart rate in chronic heart failure is depressed earlier and to a greater extent then the vagal limb.
Coalition Formation in the European Parliament

This article analyzes coalition formation within the European Parliament (EP) under the cooperation procedure through the analysis of a random sample of 100 roll call votes. The authors find that generally, coalitions form on the basis of ideology, not nationality, although they are able to identify some national groups that occasionally vote against the majority of their party group. More interestingly, they find that the political initiative within the EP belongs to the Left and that the majorities required at different stages affect not only the outcomes of votes but also the coalitions that will form. Finally, a slight variation is found in coalition building depending on the subject matter. On the basis of these findings, the authors suggest an alternative interpretation of the conflicts between the Council and EP based on an ideological conflict about more (EP) or less (Council) regulation, as opposed to more or less integration.
Experimental Salmonella infections in Crassius auratus (goldfish)

Abstract C. auratus, the common goldfish, has been experimentally infected with Salmonella typhimuriun, isolated from river fishes, and S. typhimurium var. Copenhagen, cultured from a pig. Infections had a duration of at least 91 days. Salmonellae colonized in the viscera of the fish and were in all probability shed in their feces. Fewer of the bacteria were present in the environmental water than were present within the fish during the period of the experiment. This finding confirms that colonization and multiplication of the Salmonella within the fish viscera had occurred.
Preparation and characterization of nearly domain free 123-oxide showing a superconducting transition width of ∼1.1K☆

Abstract YBa 2 Cu 3 O 7− ∂ has been prepared by coprecipitation of the corresponding metal ions by hydroxy-carbonate method. A nearly stoichiometric 123-oxide is obtained after a single firing step in flowing O 2 . This oxide shows a zerotransition temperature of 92.6 K and a transition width of ∼1.1 K. The oxides prepared at 1173 K and 12 hours of heating in flowing oxygen yield nearly twin-domain-free superconductor showing no other defect structure. We have investigated the preparation of this oxide under various preparative conditions including different pH values of precipitation.
Effects of chlorite exposure on conception rate and litters of A/J strain mice.

The use of chlorine has been almost universally accepted as the method of choice for disinfecting potable water supplies. However, recent studies have demonstrated that the interaction of chlorine with ubiquitous and naturally occurring humic acids in water results in the formation of trihalomethanes (U.S. EPA 1975, ROOK 1976) some of which are known or suspected carcinogens (MARX 1974, U.S. EPA 1975, DEROVEN & DIEM 1975a, U.S. EPA 1977a). Among these, chloroform has been shown to produce hepatomas in selected mouse and rat strains in the exposure range of 90 to 447 mg/kg of body weight (ANONYMOUS 1976, ROE 1976).
Nitrogen uptake and primary productivity rates in the Mid-Atlantic Bight (MAB)

Abstract Nutrient concentrations, primary productivity, and nitrogen uptake rates were measured in coastal waters of the Mid-Atlantic Bight over a two-year period that included measurements from all four seasons. In order to assess carbon productivity and nitrogen demand within the context of the physical environment, the region was divided into three distinct hydrographic regimes: the Chesapeake and Delaware Bay outflow plumes (PL), the southern Mid-Atlantic shelf influenced by the Gulf Stream (SS), and the mid-shelf area to the north of the Chesapeake Bay mouth (MS). Annual areal rates of total nitrogen (N) uptake were similar across all regions (10.9 ± 2.1 mol N m −2 y −1 ). However, annual areal rates of net primary productivity were higher in the outflow plume region (43 mol C m −2 y −1 ), than along the Mid-Atlantic shelf and in areas influenced by the Gulf Stream (41 and 34 mol C m −2 y −1 , respectively). Rates of net primary productivity were not well correlated with Chl a concentrations and were uncoupled with net N uptake rates. Seasonally averaged annual areal rates of net primary productivity for the Mid-Atlantic Bight measured in this study were higher than those calculated in previous decades and provide important validation information for biogeochemical models and satellite remote sensing algorithms developed for the region.
Electron mobility and terahertz detection using silicon MOSFETs

Abstract Based on the mobility calculations, we investigate the possibility of using deep submicron silicon MOSFETs for the detection and emission of terahertz radiation via the excitation of the surface plasma waves in the device channels. This analysis shows the possibility of using the MOSFET-based terahertz detector and emitter pairs for the wireless interconnects for the future VLSI chips.