cssi/SciSciGPT-SciSciNet huggingface dataset:
The Chemistry of Silicon Deposition from Hydride Decomposition

Kinetic studies of Si CVD from SiH4 were carried out under conditions permitting separation of the process into its SiH4 and homogeneous (Si2H6, Si3H8 and higher hydride) reaction components. The reactivities of the individual species on atomically clean Si(111)−(7×7) surfaces were also measured. These experiments illustrate the information that must be obtained before attempting to model the overall CVD reaction.
The Influence of Eddies on Coral Larval Retention in the Flower Garden Banks

While coral larval exchange among reef patches is crucial to the persistence of coral metapopulations, larval retention within patches is critical for local population maintenance. In isolated systems such as the Flower Garden Banks (FGB) of the NW Gulf of Mexico (GoM), local retention is thought to play an important role in maintaining high levels of coral cover. Numerous mesoscale cyclonic and anticyclonic features (eddies) are known to spin off from the GoM’s Loop Current, many of which pass over the FGB. We developed a biophysical model of coral larval dispersal (2004–2018) to investigate the extent to which eddies may facilitate coral larval exchange between and within the East and West FGB. Virtual larvae of the broadcast spawning Orbicella faveolata and the brooding Porites astreoides were released and tracked with species-specific reproductive and larval behaviors to investigate differences in retention and connectivity in corals with contrasting life histories. Eddies were detected and tracked using sea surface altimetry and compared with larval trajectories to assess the retentive characteristics of these features. Results suggest consistently high, but species-specific, levels of local retention and cross-bank connectivity in both coral species. High local retention is possible early in the dispersal of P. astreoides, and both species routinely experience retention due to recirculation in eddy features as late as 30 days after planulation or spawning. Eddies passing over the FGB were associated with pulses of between- and within-bank retention, indicating that larvae are capable of dispersing from and returning to coral reefs in the NW GoM. Although opportunities for retention are inherently ephemeral and stochastic due to the nature of Loop Current eddy shedding, eddy propagation should serve as a reliable reseeding mechanism for FGB coral populations. In particular, peaks in late summer eddy propagation correspond with mass coral spawning and may enhance larval retention. These findings support the assertions that healthy FGB reefs may be largely self-sustaining, and that persistent, self-sustaining populations at the FGB may supply downstream reefs with larvae and behave as a remote climate change refugium.
Drugs Used in Ophthalmology

Abstract This book is intended as a guide to help the clinician determine where a visual problem is a drug-induced ocular side effect. We continually review spontaneous case reports from the National Registry of Drug-Induced Ocular Side Effects, the World Health Organization, the US Food and Drug Administration, and the world literature. We have attempted to classify a suspected adverse event with our impression to causality (i.e. certain, probable, unlikely, conditional/unclassified). This chapter discusses drugs used in ophthalmology including drugs used to treat age-related macular degeneration, drugs used to treat allergies, drugs used to treat glaucoma, anti-infectives, antiviral drugs, carbonic anhydrase inhibitors, decongestants, miotics, mydriatics and cycloplegics, neurotoxins, ophthalmic dyes, ophthalmic implants and injectable gases, ophthalmic preservatives and antiseptics, proteolytic enzymes, surgical adjuncts, topical local anesthetics, topical ocular nonsteroidal anti-inflammatory drugs, topical osmotic drugs, and viscoelastics.
Perceived reproductive health needs among Muslim women in the southern US

Despite growing rates of Muslims in the United States, we know little about the health of Muslim women in this country. Due to the stigma surrounding sex, sexuality, and the cultural beliefs of this population, there may be unique and unknown challenges regarding access to reproductive health care for Muslims in the US. Purpose: This study aims to examine variables that promote and impede access to reproductive health care for Muslim women in the southern US. Methods: This multi-method study included in-person semi-structured interviews (n=15) and an anonymous online survey (n=76). Findings: Participants generally had low rates of gynecological care and cervical cancer screening. The cultural (e.g. waiting for marriage to receive gynecological care) and contextual aspects (e.g. gender) that increased or restricted access to care in terms of screening, providers and education are discussed. We also identified some misconceptions related to screening and contraception. Conclusions: Influences on reproductive health care experienced by participants in this study have similarities yet are distinct from Muslim populations in other countries as well as other groups of women in the US. This study points to a need for more population-focused education of providers, as well as awareness about reproductive health and health care recommendations and access for Muslim women.
Alternating current electrolysis for organic synthesis

Abstract Electrochemical organic synthesis has recently attracted much attention because of its unique reactivity and environmentally benign approach. Conventional electrosynthesis uses either constant current or constant potential, known as direct current electrolysis. However, recently, alternating current electrolysis has begun receiving more attention. The purpose of this study is to give a short overview of the history and recent advances in the field of alternating current electrolysis for organic synthesis.
Changes in Health Care Use Among Undocumented Patients, 2014-2018.

Importance The 2016 presidential campaign was marked by intensified rhetoric around the deportation of undocumented immigrants. The association of such rhetoric with primary, emergency, and inpatient care among undocumented immigrants is unclear. Objective To examine the association of increased anti-immigrant rhetoric during the 2016 presidential campaign with health care use among a group of Medicaid-ineligible patients largely composed of undocumented immigrants. Design, Setting, and Participants Using a difference-in-differences (DID) approach, this cohort study analyzed health care use between January 1, 2014, and May 31, 2018, in a retrospective cohort of Medicaid and Medicaid-ineligible (>90% undocumented) adult and pediatric patients. The inflection point of interest was June 16, 2015, the date of Donald Trump’s announcement of candidacy, which represented a documented increase in anti-immigration rhetoric during the presidential campaign. Analyses were controlled for age, self-reported sex, and baseline comorbidities. Data analysis was conducted from August 28, 2018, to September 1, 2020. Main Outcomes and Measures The DID of the number of completed primary care encounters before and after June 16, 2015, in Medicaid compared with Medicaid-ineligible patients. Secondary outcomes included the DID of emergency department (ED) visits and inpatient discharges over the same period. Results There were 20 211 patients included in the analysis: 1501 (7.4%) in the sample of predominantly undocumented Medicaid-ineligible patients (861 [57.4%] female) and 18 710 (92.6%) in the Medicaid control group (10 443 [55.8%] female). The mean (SD) age as of 2018 in the Medicaid-ineligible group was 38.2 (15.4) years compared with 22.2 (16.5) years in the control group. There was a differential decrease in completed visits among Medicaid-ineligible children compared with Medicaid children (DID estimate, 0.8; 95% CI, 0.7-0.9) and Medicaid-ineligible adults (DID estimate, 0.8; 95% CI, 0.8-0.9). There was also a significant differential increase in ED visits among Medicaid-ineligible children (DID estimate, 2.3; 95% CI, 1.1-5.0). In addition, there was a differential decrease in inpatient discharges among Medicaid-ineligible adults (DID estimate, 0.5; 95% CI, 0.4-0.7), with no significant change in ED visits or ED admission rates in this group. Conclusions and Relevance In this cohort study, there was a significant decrease in primary care use among undocumented patients during a period of increased anti-immigrant rhetoric associated with the 2016 presidential campaign, coincident with an increase in ED visits among children and a decrease in inpatient discharges among adults, with the latter possibly attributed to a decrease in elective admissions during this period.
Wafer Level System Integration of the Fifth Generation CoWoS®-S with High Performance Si Interposer at 2500 mm2

Chip-on-Wafer-on-Substrate with Si interposer (CoWoS-S) is a TSV-based multi-chip integration technology that is widely used in high performance computing (HPC) and artificial intelligence (AI) accelerator area due to its flexibility to accommodate multiple chips of SoC, chiplet, and 3D stacks such as high bandwidth memory (HBM). The interposer size increases steadily over the past few years, from one full reticle size (∼830 mm2) to two reticle size (∼1700 mm2). The growth of interposer size offers more integration power to accommodate more active silicon in a package to satisfy the HPC/AI needs. In this paper, we report the new 5th generation CoWoS-S (CoWoS-S5) based on a Si interposer as large as three full reticle size (∼2500 mm2) by a novel 2-way lithography stitching approach. This will accommodate a multiple of logic chips at a total area of 1200 mm2 (with chiplets) together with eight HBM stacks. Besides the dimensional increase of the Si interposer, new features are incorporated to further enhance the electrical and thermal performances of CoWoS-S5 compared with the previous CoWoS-S portfolio. These include an integrated deep trench capacitor (iCap) for enhanced power integrity, 5 layers of sub-micron Cu interconnect with reduced sheet resistance to satisfy high speed die to die interconnect, new TSV structure interposer for both return and insertion loss reduction, and a higher thermal conductivity thermal interface material (TIM) to achieve a lower thermal resistance. Component level reliability with excellent electrical and physical results are also discussed.
Good Faith: Balancing the Right to Manage with the Right to Represent

This paper demonstrates that the obligation of good faith is a valid contractual limitation on management discretion. By explicitly and conclusively recognizing bad faith behavior as a breach of a contractual obligation, however, the delicate balance between control and liberty in the collective bargaining agreement will be assured.
INTERRELATIONSHIP BETWEEN NK ACTIVITY AND T CELL-MEDIATED IMMUNITY IN SYNGENEIC TUMOR REJECTION

Publisher Summary This chapter examines interrelationship between natural killer (NK) activity and T-cell-mediated immunity in syngeneic tumor rejection. The study described in the chapter used direct isolation of effector cells from the site of injection of viable tumor cells, that is, the peritoneal cavity. With this direct analysis, the in vivo relevance of the study seemed to be less questionable because none of the effector cells had to be subjected to any long-term culturing in vitro prior to testing. Thus, mice were injected with 1591 parental regressor tumor cells or with a subtumorigenic dose of 1591 progressor variant tumor cells and 8 days later effector cells were removed from the peritoneal cavities of these animals and tested for cytolytic activity. Animals injected with the parental 1591 tumor cells developed Lyt-2 + T cells which lysed the 1591 tumor cells. Neither the antigenically distinct UV-induced 1316 tumor cells nor seven independently isolated 1591 progressor variant cells lines were lysed. It was shown that Lyt-2 + tumor-specific reactivity could not be elicited by the injection of progressor variant tumor cells. Injection of progressor variant cells induced high levels of some other type of Lyt-2 − cytolytic effector cell.
Java simulation and robot modeling of the Cataglyphis Bicolor

This summer we participated in a program at a college in a town, state. For this program, we researched and experimented with simulations of the desert ant Cataglyphis Bicolor. We wrote a Java simulation and constructed a Lego robot to help us understand and emulate the behaviors that we found in our research. Our intensive research aided our efforts to understand the methods that we needed to employ to create the most accurate model.
SURVEY OF DRIVER SEATING POSITIONS IN RELATION TO THE STEERING WHEEL

Research indicates the risk of serious injury from an inflating airbag for belted drivers is very low if there is a clearance of 10 in. (25.4 cm) or more between the center of the steering wheel and the center of drivers' chests. The current study examines driver seating positions, in particular drivers' proximity to steering wheels. This study estimates about 5% of the U.S. female population sits closer than 10 in. (25.4 cm) from the steering wheel. This percentage increases to 35% for female drivers shorter than 60.5 in. (1.54 m) (the smallest 10% of the female population). Of the females sitting closer than 10 in. (25.4 cm), 66% sit within 9-10 in. (22.9-25.4 cm), and 17% sit within 8-9 in. (20.3-22.9 cm). In a separate study, both female and male drivers sitting within 9-10 in. (22.9-25.4 cm) were able to increase this distance to 10 in. (25.4 cm) or more and still drive comfortably in a number of cars (representing various car sizes) by making a few minor seating adjustments.
Houses, Banks, and Financial Markets: Why the Crisis this Time?

The current global economic and financial crises are alarming in both severity and length. We study the anatomy of the collapse by comparing the current precipitant (housing crisis) with the previous U.S. housing crisis of the early 1990s. Our analysis suggests that the greater severity of this episode is driven by several factors: default proclivity (to typical triggers) and bank lending retrenchment are different across the previous and current episodes. Most importantly however, we document different linkages between the housing sector, the banking sector and stock market across the two episodes. We conclude that the duration of the current episode is likely to significantly exceed the duration of the prior episode.
MAKING AND USING STONE TOOLS: ADVICE FOR LEARNERS AND TEACHERS AND INSIGHTS FOR ARCHAEOLOGISTS

Gaining experience with stone tool technology can be an important part of professional archaeological training as well as a valuable learning experience in its own right. This paper summarizes its author's insights gained from making and using stone tools and from teaching these skills to college students for more than two decades. It argues that teaching stone tool production and use to a wider audience will, in the long term, provide a baseline against which to measure archaeological lithic variation.
Dissent and games as a consideration in decision making: Case of Solar Photovoltaic Technologies

Research in decision modeling has mainly focused on the ranking of alternative choices based on a consensus or combined judgments of experts and decision makers. However, a decision model can also be used to form the basis of rational conflict and dissent. This is a novel approach. This paper examines the case of a hierarchical decision model that is used to assess alternative solar photovoltaic (PV) technologies under multiple perspectives. The perspectives include: social, technical, economic, environmental, and political. Dissent is evident if only one dominant perspective is considered to evaluate the alternate PV technologies. By using such a decision modeling approach we are able to observe outcomes for both consensus and dissent scenarios. In recent times game theory is defined as the science of interactive decision making. We can also consider a more general definition of game theory as a field of strategic decision making utilizing mathematical models that represent rational decision-makers for conflict and cooperation. This study could be developed further to form a basis of game theory with a large number of players and preferences.
Subverting Subversion: A Review on the Breast Cancer Microenvironment and Therapeutic Opportunities.

This review combines the recent research on the subject of tumor immunology and methods of correcting the immune system’s ­reaction to the tumor microenvironment while impeding the survival and growth of tumor cells, with a focus on breast cancer. Induction of hypoxia-inducible genes in the microenvironment leads to lowering of its pH. This impedes the adaptive immune response and acts to recruit cells of the immune system, which suppress the immune response. Regulatory T-cells (Tregs), myeloid-derived suppressor cells (MDSCs), and their derivatives coordinate an anti-autoimmunity response and a healing response in concert with tumor-secreted cytokines, enzymes, and antigens. Together, they suppress a proper immune reaction to tumor cells and promote cellular reproduction (Fig. 1). In addition, the hypoxia-inducible response and components of the tumor microenvironment such as cancer-associated fibroblasts (CAFs) also create an ideal environment for tumor growth and metastasis via neoangiogenesis and increased motility. Broad-spectrum chemotherapy drugs are problematic as breast cancer cells develop resistance through selective loss of a novel target and downregulation of apoptotic factors. A better understanding of the tumor microenvironment offers new therapeutic opportunities to rescue the immune response, inhibit cancer cell growth pathways, and subvert the tumor microenvironment with little toxicity and side effects.
Privacy and Data Protection in Business: Laws and Practices

In the fields of digital privacy and data protection in the business world, effective compliance and risk management require not only knowledge of applicable laws and regulations, but at least a basic understanding of relevant technologies and the processes of the company or other organization that is collecting and/or using the personal information or monitoring behavior. This book is structured to provide a framework for law and other students to both learn the law and place it in the necessary technological and practical context, divided into topic areas such as children’s privacy, health information, governmental requirements, employee data and more. The examples and best practices, questions and links to additional materials contained within each chapter (and supplemented through dedicated Web-based content) should be approached by readers not only as aids to understanding the law, but as guides for future counseling and decisionmaking.
How does the pathophysiological context influence delivery of bone growth factors

“Orthobiologics” represents an important category of therapeutics for the regeneration of bone defects caused by injuries or diseases, and bone growth factors are a particularly rapidly growing sub-category. Clinical application of bone growth factors has accelerated in the last two decades with the introduction of BMPs into clinical bone repair. Optimal use of growth factor-mediated treatments heavily relies on controlled delivery, which can substantially influence the local growth factor dose, release kinetics, and biological activity. The characteristics of the surrounding environment, or “context”, during delivery can dictate growth factor loading efficiency, release and biological activity. This review discusses the influence of the surrounding environment on therapeutic delivery of bone growth factors. We specifically focus on pathophysiological components, including soluble components and cells, and how they can actively influence the therapeutic delivery and perhaps efficacy of bone growth factors.
Matrix metalloproteinases in stem cell regulation and cancer

Since Gross and Lapiere firstly discovered matrix metalloproteinases (MMPs) as important collagenolytic enzymes during amphibian tadpole morphogenesis in 1962, this intriguing family of extracellular proteinases has been implicated in various processes of developmental biology. However, the pathogenic roles of MMPs in human diseases such as cancer have also garnered widespread attention. The most straightforward explanation for their role in cancer is that MMPs, through extracellular matrix degradation, pave the way for tumor cell invasion and metastasis. While this notion may be true for many circumstances, we now know that, depending on the context, MMPs may employ additional modes of functionality. Here, we will give an update on the function of MMPs in development and cancer, which may directly regulate signaling pathways that control tissue homeostasis and may even work in a non-proteolytic manner. These novel findings about the functionality of MMPs have important implications for MMP inhibitor design and may allow us to revisit MMPs as drug targets in the context of cancer and other diseases.
Functional changes in glutamate transporters and astrocyte biophysical properties in a rodent model of focal cortical dysplasia

Cortical dysplasia is associated with intractable epilepsy and developmental delay in young children. Recent work with the rat freeze-induced focal cortical dysplasia (FCD) model has demonstrated that hyperexcitability in the dysplastic cortex is due in part to higher levels of extracellular glutamate. Astrocyte glutamate transporters play a pivotal role in cortical maintaining extracellular glutamate concentrations. Here we examined the function of astrocytic glutamate transporters in a FCD model in rats. Neocortical freeze lesions were made in postnatal day (PN) 1 rat pups and whole cell electrophysiological recordings and biochemical studies were performed at PN 21-28. Synaptically evoked glutamate transporter currents in astrocytes showed a near 10-fold reduction in amplitude compared to sham operated controls. Astrocyte glutamate transporter currents from lesioned animals were also significantly reduced when challenged exogenously applied glutamate. Reduced astrocytic glutamate transport clearance contributed to increased NMDA receptor-mediated current decay kinetics in lesioned animals. The electrophysiological profile of astrocytes in the lesion group was also markedly changed compared to sham operated animals. Control astrocytes demonstrate large-amplitude linear leak currents in response to voltage-steps whereas astrocytes in lesioned animals demonstrated significantly smaller voltage-activated inward and outward currents. Significant decreases in astrocyte resting membrane potential and increases in input resistance were observed in lesioned animals. However, Western blotting, immunohistochemistry and quantitative PCR demonstrated no differences in the expression of the astrocytic glutamate transporter GLT-1 in lesioned animals relative to controls. These data suggest that, in the absence of changes in protein or mRNA expression levels, functional changes in astrocytic glutamate transporters contribute to neuronal hyperexcitability in the FCD model.
Thermal injury and shrinkage in human skin in vitro after Tru-Pulse, Silktouch, and Ultrapulse exposure: preliminary results

An increasing number of lasers are in clinical use for treatment of facial rhytides and scars. Each one of these lasers has a significantly different delivery profile while sharing a photothermal mechanism to ablate surface layers of skin. The biological mechanism by which smoother skin results is still under study. Factors in achieving clinical improvement may include tissue ablation, tissue shrinkage, and the inflammatory response produced by the layer of thermally injured dermis which underlies the ablated skin or produced by the need to heal a large raw skin surface. Clinical results suggest that the available lasers all produce some measure of the 'resurfacing effect.' Given the diversity of delivery parameters employed, a comparison of the tissue effects would be useful. We sought to compare the depth of thermal injury and the degree of tissue shrinkage produced by three commonly used resurfacing lasers.
Ultrastructure of the ventricular tissue of the hibernating ground squirrel, Citelluslateralis, in relation to the physiology of the hibernator's heart

Abstract 1. 1. The ventricular tissue of the hibernating ground squirrel, Citellus lateralis , has been shown to be ultrastructurally similar to non-hibernating mammalian hearts. 2. 2. The sarcolemma, mitochondria, golgi zones, nuclei and myofibrils appear similar to those of other mammals. Internal and peripheral cell membrane couplings are similar to those of six non-hibernating mammals previously examined. 3. 3. These data are in conflict with other previous investigations. 4. 4. Additionally no ultrastructural difference was observed between active (37°C) and hibernating (5°C) squirrel hearts. 5. 5. These data suggest that the physiological differences between hibernators' and non-hibernators' hearts are due to differences in molecular configurations.
HIV and maternal mortality.

The majority of the 17 million women globally that are estimated to be infected with HIV live in Sub-Saharan Africa. Worldwide, HIV-related causes contributed to 19 000–56 000 maternal deaths in 2011 (6%–20% of maternal deaths). HIV-infected pregnant women have two to 10 times the risk of dying during pregnancy and the postpartum period compared with uninfected pregnant women. Many of these deaths can be prevented with the implementation of high-quality obstetric care, prevention and treatment of common co-infections, and treatment of HIV with ART. The paper summarizes what is known about HIV disease progression in pregnancy, specific causes of HIV-related maternal deaths, and the potential impact of treatment with antiretroviral therapy on maternal mortality. Recommendations are proposed for improving maternal health and decreasing maternal mortality among HIV-infected women based on existing evidence.
Bayesian T Tests for Accepting and Rejecting the Null Hypothesis

Progress in science often comes from discovering invariances in relationships among variables; these invariances often correspond to null hypotheses. As is commonly known, it is not possible to state evidence for the null hypothesis in conventional significance testing. Here we highlight a Bayes factor alternative to the conventional t test that will allow researchers to express preference for either the null hypothesis or the alternative. The Bayes factor has a natural and straightforward interpretation, is based on reasonable assumptions, and has better properties than other methods of inference that have been advocated in the psychological literature. To facilitate use of the Bayes factor, we provide an easy-to-use, Web-based program that performs the necessary calculations.
Dipolar resonance in the plane-wave scattering by an axially magnetized ferrite cylinder

The scattering of E-polarized plane waves by an infinitely long axially magnetized ferrite cylinder is investigated for the case in which the radius of the cylinder is small in comparison with the wavelength of the incident wave. The scattering amplitude is found to have a maximum at a single resonant frequency whose approximate expression in terms of the physical parameters is deduced.
Irrelevant stimulus dimensions and dimensional transfer in the discrimination learning of children

Abstract This experiment studied the learning of four extradimensional shifts by kindergarten children. These shifts differed with respect to the manner in which the irrelevant stimulus dimension of Problem 2 varied (within vs. between trials) and the status of this dimension in Problem 1 (relevant vs. constant). The main finding was that extradimensional shifts were learned faster when the irrelevant dimension of Problem 2 varied between trials and was constant within trials. This finding suggests that attention is not elicited so readily by dimensions which are constant within trials as by dimensions which vary within trials. The finding also allows for the consistent interpretation of many of the diserepant results of studies comparing reversal and extradimensional shifts. Performance was not affected by the status of the irrelevant Problem-2 dimension in Problem 1.
Surface observation of nickel-plated iron single crystals deformed at 77 K

Abstract The surface morphology of nickel-plated iron single crystals deformed at 77 K has been investigated to identify the mechanism of surface film softening. Two types of striation were found to form on the specimen surfaces, i.e. cracks approximately perpendicular to the tensile axis on the edge-faces and slip-like lines on the screw-faces. The direction of these lines deviated from the traces of the primary slip planes. Specimens which were electroplated on only one of the edge-faces exhibited a clear correspondence between the cracks on the plated face and the slip steps on the unplated face. Both the cracks and the slip steps were irregularly jogged. The lines connecting the corresponding points on the two faces were parallel to the primary slip direction. The observations indicate that dislocation loops are generated near the cracks below the stress level for screw dislocation motion. As the edge component of these loops can move substantially at the low stress level, the generation of a large number of dislocation loops results in macroscopic deformation. The observed angle of deviation between the direction of the slip-like lines and the trace of the primary slip plane on the screw-face is consistent with this model.
Incorporation of a Designed Ruthenium Nitrosyl in PolyHEMA Hydrogel and Light-Activated Delivery of NO to Myoglobin

A ruthenium nitrosyl with 4-vinylpyridine (4-vpy) as one ligand, namely, [Ru(Me2bpb)(NO)(4-vpy)](BF4) (1), has been synthesized and structurally characterized. This diamagnetic {Ru−NO}6 nitrosyl is photoactive and readily releases NO upon exposure to low-intensity (5−10 mW) UV light (quantum yield at 300 nm = 0.18). Radical-induced copolymerization of 2-hydroxyethyl methacrylate (HEMA) and ethyleneglycol dimethacrylate (EGDMA) in the presence of 1 has afforded a 1-pHEMA, a transparent hydrogel in which 1 is covalently attached to the polymer backbone. Exposure of 1-pHEMA to UV light (5−10 mW) results in rapid release of NO (detected by NO electrode) that can be delivered to biological targets such as myoglobin. The photoactivity of 1-pHEMA is strictly dependent on exposure to UV light.
Early events in valvulogenesis: A signaling perspective

The proper formation and function of the vertebrate heart requires a multitude of specific cell and tissue interactions. These interactions drive the early specification and assembly of components of the cardiovascular system that lead to a functioning system before the attainment of the definitive cardiac and vascular structures seen in the adult. Many of these adult structures are hypothesized to require both proper molecular and physical cues to form correctly. Unlike any other organ system in the embryo, the cardiovascular system requires concurrent function and formation for the embryo to survive. An example of this complex interaction between molecular and physical cues is the formation of the valves of the heart. Both molecular cues that regulate cell transformation, migration, and extracellular matrix deposition, and physical cues emanating from the beating heart, as well as hemodynamic forces, are required for valvulogenesis. This review will focus on molecules and emerging pathways that guide early events in valvulogenesis.
Light dependence of the decay of the proton gradient in broken chloroplasts.

Abstract The initial rates and steady-state values of proton uptake by broken chloroplasts have been measured as functions of light intensity at various concentrations of chlorophyll, pyocyanine, supporting electrolyte, buffer, as well as pH and temperature. Kinetic analysis of the data shows that the rate of decay of proton gradient due to backward leakage depends on light intensity. Under steady illumination, the decay constant k L is equal to k D + mR 0 , where R 0 is the initial rate of proton uptake which is a function of light intensity, k D is the decay constant in the dark and m is a parameter which is independent of light intensity. Treatment of chloroplasts with lysolecithin, neutral detergent, 2,4-dinitrophenol, or valinomycin in the presence of K + increases k D without affecting m . Treatment with N , N ′-dicyclohexylcarbodiimide or adenylyl imidodiphosphate under appropriate conditions decreases m without affecting k D . Treatment with glutaraldehyde makes k L independent of light intensity and hence m = 0. These results suggest that the light-dependent part (mR 0 ) of k L is due to leakage of protons through the coupling factor (CF 1 -CF 0 ) complex which can open or close depending on light intensity and that the light-independent part ( k D ) of the decay constant k L is due to proton leakage elsewhere.
Intracellular Accumulation of Azithromycin by Cultured Human Fibroblasts

Azithromycin was shown to achieve high concentrations in human skin fibroblasts. Intracellular penetration occurred rapidly (10 micrograms/mg of cellular protein after 3 h) and then increased progressively over a 3-day period; azithromycin accumulated up to 21 times more than erythromycin (61.1 versus 2.9 micrograms/mg of protein). Uptake was dependent on the extracellular concentration, was inhibited at 4 degrees C, did not occur in nonviable cells, and was reduced by a low pH. Intracellular accumulation was not affected by the metabolic inhibitor 2,4-dinitrophenol or sodium fluoride or by the nucleoside transport inhibitor 2-chloradenosine. Once concentrated in cells, azithromycin remained intracellular and was released slowly in the absence of extracellular drug, compared with erythromycin (17 versus 78% released after 1 h). After 48 h of incubation in drug-free medium, 27% of the initial amount of azithromycin remained cell associated. The release of azithromycin was not affected by various monokines reported to stimulate fibroblasts (interleukin-1 or tumor necrosis factor) or by exposure to bacteria. Incubation of azithromycin-loaded fibroblasts with human polymorphonuclear leukocytes resulted in a higher intracellular accumulation of azithromycin in polymorphonuclear leukocytes than in cells incubated with free nonintracellular azithromycin for the same time (8.3 versus 2.2 micrograms/ml after 2 h), suggesting a more efficient or rapid uptake through cell-to-cell interaction. The widespread distribution of fibroblasts in tissues suggests a potential for these cells, and possibly other lysosome-containing tissue cells, to serve as a reservoir for azithromycin, slowly releasing it for activity against extracellular organisms at sites of infection and passing it to phagocytes for activity against intracellular pathogens and potential transport to sites of infection.
α-Galactosyl epitopes on glycoproteins of porcine renal extracellular matrix

α-Galactosyl epitopes on glycoproteins of porcine renal extracellular matrix. Background The pig is the donor animal of choice for human xenotransplantation. In the most relevant pig-to-baboon model, pig organs transplanted into baboons are hyperacutely rejected by natural xenoantibodies, which mainly bind to α-galactosyl (αGal) epitopes expressed at the surface of endothelial cells. Recent advances in controlling hyperacute rejection have led to improved survival of these xenografts, and it is now important to identify αGal binding sites in other cells and tissues that may be subject to immunologic attack. To this end, we have studied whether αGal antibodies bind to glycated proteins of the extracellular matrix in the kidney and other organs most likely to be used for human xenotransplantation. Methods High-titer anti-αGal antibodies, similar to human natural xenoantibodies, were prepared in baboons, and their reactivity with components of pig extracellular matrix was tested by serology and immunohistology. Results The antibodies recognized epitopes of immobilized murine, bovine or porcine thyroglobulin, laminin, heparan sulfate proteoglycans, and fibronectin. In sections of pig tissue, the antibodies bound to endothelial and certain epithelial cells, as shown in previous studies, and also to mesenchymal cells, basement membranes, and extracellular matrices, in which they colocalized with matrix glycoproteins, especially laminin and heparan sulfate proteoglycans. Conclusions These results suggest that when pig xenografts can be made to survive for prolonged periods, the reactivity of αGal antibody with matrix molecules can induce basement membrane and matrix lesions similar to those induced in laboratory animals by antilaminin and antiheparan sulfate proteoglycans antibodies.
Social, Emotional, and Academic Competence Among Children Who Have Had Contact With Child Protective Services: Prevalence and Stability Estimates

ABSTRACT Objective To estimate the prevalence and stability of social, emotional, and academic competence in a nationally representative sample of children involved with child protective services. Method Children were assessed as part of the National Survey of Child and Adolescent Well-Being. Children ( N = 2,065) ranged in age from 8 to 16 years and were assessed at baseline and at 18 and 36 months postbaseline. Caregivers, teachers, and youths provided information about children's problem behaviors, school achievement, and social competence. Children were considered resilient in a domain if they met or exceeded national norms. Results Thirty-seven percent to 49% of children demonstrated resilience in mental health, academic, or social domains at any time point. Eleven percent to 14% of children were resilient across domains at any time point, and only 14% to 22% of children were consistently resilient within a given domain across all three time points. Conclusions Resilience, as defined by competence in mental health, academic, and social domains, was demonstrated by relatively few children. The conditions that promote stable resilience may be difficult to achieve among allegedly maltreated children who are likely to face residential and caretaker instability. Future research should identify processes that promote stability in resilience over time.
Evidence for Polynuclear Aromatic Hydrocarbons in the Diet of Bottom-Feeding Fish

Among environmental pollutants, polynuclear aromatic hydrocarbons (PAH) are of interest because of their widespread occurrence and the human carcinogenicity of their metabolic products. Most PAH are relatively water insoluble and ultimately are deposited in sediments. In localized areas of eastern Lake Erie, sediments have been shown to have high concentrations of PAH. As a part of an ongoing research on environmental carcinogenesis, the authors have been examining possible routes of exposure to carcinogens in feral fish. They report here data indicating that the diet of bottom-feeding fish can contain substantial concentrations of PAH. Some of these PAH can be metabolically activated to carcinogens and may be involved in neoplasia in these fish.
Headache as a Presentation of Angina: Reproduction of Symptoms During Angioplasty

SYNOPSIS We report a case of angina presenting as headache in a 59-year-old man. Headaches were relieved by nitroglycerin and were reproduced by occlusion of the first obtuse marginal artery during angioplasty. Headaches resolved after successful angioplasty. The temporal relationship between coronary artery occlusion and the headache suggests that headache angina is due to referred pain rather than a generalized vaso-spastic disorder.
TRACE CONTAMINANT ACCUMULATION BY ORGANISMS GROWN IN A WASTE RECYCLING AQUACULTURE SYSTEM1

Three species of bivalve mollusc Crassostrea gigas (Thunberg), Ostrea edulis L., Tapes philippinarum (Adams and Reeve), one species of crustacean, Homarus americanus, and one species of macroscopic algae Gracilariopsis sjostedtii were grown in a pilot-scale marine waste recycling aquaculture system for a period of 18 months. Organisms were exposed to 14 different regimes of food chain enrichment using either secondary treated sewage effluent, a mixture of inorganic nitrogen and phosphorus compounds free of contaminants, or a combination of both to simulate “growth” and “depuration” periods in an on-site application. Throughout the study organisms were sacrificed at monthly intervals and assayed for 7 trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn). Sewage effluent used for food chain enrichment was assayed for the same suite of metals three times per week. No significant differences were evident between organisms cultured in the contaminant-free and effluent enriched regimes. Shellfish trace metal contents were consistently below FDA “alert” levels. H. americanus trace metal levels were within acceptable standards for human consumption. Trace metal levels in G. sjostedtii were comparable with those recorded for natural populations of macrophytes. Data suggest that trace metals constitute a minimal public health problem in organisms cultured for human consumption in waste recycling systems; however, problems related to organic residues and viruses have yet to be fully evaluated.
Selection of calcium isotopes for secondary ion mass spectrometric analysis of biological material

SUMMARY The use of stable isotopes as tracers for elemental localization is a function of the background count rate which is dependent upon both the natural abundance and the quantity of interferences at the nominal mass. The occurrence of a variable and unpredictable high background count rate at mass 44+ in biological tissue, probably CO2+, limits the usefulness of this isotope for physiological problems.
First report of downy mildew caused by a Peronospora sp. on Basil in Florida and the United States.

Basil is grown as a specialty crop in greenhouse and field production in Florida and other regions of the United States. Downy mildew on basil (Ocimum basilicum) was detected from four production sites (Collier, Hendry, Miami-Dade, and Palm Beach counties) in south Florida in the fall of 2007, and within months, it was also found in west-central north Florida (Hillsborough County). Incidence reached nearly 100% on some of the affected crops and caused complete yield losses on basil grown both in the field for fresh market and potted herbs market. Symptoms developed during transit on basil that appeared symptomless at harvest. Symptoms initially appeared as yellowing on the lower leaves that was typically delineated by the veins, although in some cases the entire leaf area of the leaf surface was affected. A gray, fuzzy growth was apparent on the abaxial leaf surface. Microscopic observation detected dichotomous branching, hyaline sporangiophores (220 to 750 × 4 to 9 μm) bearing single sporangia. Sporangia were light brown, ovoid to slightly ellipsoid, and measured 14 to 15 × 15 to 18 μm. Oospores were not observed. Leaves of potted basil plants and coleus (Solenostemon scutellarioides) were inoculated with a suspension containing 1 × 105 sporangia/ml and sprayed till runoff (approximately 15 ml per plant) with a hand-held pressurized aerosol canister. Plants were covered with a plastic bag for 24 h and maintained in the greenhouse under ambient conditions. Noninoculated plants served as controls. After 7 days, symptoms typical of downy mildew occurred only on the inoculated basil plants and sporulation was confirmed microscopically. The internal transcribed spacer regions of an isolate collected in Hendry County were sequenced bidirectionally. The consensus sequence was deposited into GenBank (Accession No. FJ346561). Sequence data matched (100% homology) with a Peronospora sp. reported on sweet basil in Switzerland (GenBank Accession No. AY884605) and was similar (99% homology) to an isolate (GenBank Accession No. DQ523586) reported on coleus, although inoculation to coleus failed to confirm pathogenicity on this host. The sequence data also distinguished the isolate from P. lamii (87% homology) previously reported to occur on basil. The pathogen was identified as a Peronospora sp. based on morphological characteristics and sequencing homology (1-3). References: (1) L. Belbahri et al. Mycol. Res. 109:1276, 2005. (2) S. Francis. CMI Descriptions of Pathogenic Fungi and Bacteria. No. 688. CMI, Kew, England, 1981. (3) A. McLeod et al. Plant Dis. 90:1115, 2006.
Effect of DNA structure and nucleotide sequence on holliday junction resolution by a Saccharomyces cerevisiae endonuclease

Abstract Previous studies have demonstrated that mitotic Saccharomyces cerevisiae cells contain an endonuclease that cleaves Holliday junctions. In this paper, the cleavage of a number of model branched substrates has been characterized in detail. Three-armed Y-branched molecules were not substrates for the enzyme. Holliday junction substrates constructed from wild-type lambda att sites were resolved in a concerted reaction by paired single-strand breaks that contained 5′-phosphate and 3′-hydroxyl groups and were often symmetrically related. Holliday junctions were also constructed using DNAs derived from lambda safG and safT mutants to alter the nucleotide sequence immediately flanking the cross-strand exchange. These one to six base-pair changes in nucleotide sequence were observed to have dramatic effects on both the directionality and rate of resolution. More than 90% of wild-type junctions were cleaved in only one direction, while Holliday junctions composed of safT DNA were cleaved equally in both possible directions. Hybrid junctions composed of half wild-type DNA and half safG DNA were cleaved in the same orientation as the wild-type junction but at one-seventh of the rate, while junctions constructed completely from safG DNA were not cleaved at all. The cleavage sites were mapped at the nucleotide level and the locations of the paired nicks made by the endonuclease were also found to be affected by the sequence of the substrates and in such a way as to account for the directionality of cleavage. These results have important consequences for the interpretation of genetic experiments, since they provide biochemical evidence that some of the non-random nature of genetic recombination might be due to non-randomly distributed resolution processes.