cssi/SciSciGPT-SciSciNet huggingface dataset:
Substance Use Profiles Among Urban Adolescents: The Role of Family-Based Adversities

The purpose of this study is to advance our understanding of family-based adversities and adolescent well-being by examining variability in substance use profiles among urban, low-income and predominantly African American adolescents (n = 2858). Latent class analysis and regressions were used to identify the nature and correlates of heterogeneity in substance use patterns among adolescents in the Mobile Youth Survey (MYS). Analyses revealed the presence of four underlying subgroups of youth: non-users (48.4%), alcohol users (17.6%), alcohol and marijuana users (31.6%), and polysubstance users (2.5%). Membership in classes varied by age and gender, with older youth and males being more likely to belong to groups characterized by the use of multiple substances. Youth who reported that someone in their household had been arrested were more likely to belong to one of the substance using groups than the non-use group, and youth who reported not having a father figure were more likely to belong to groups characterized by the use of multiple substances relative to the non-use group. Youth who reported living with two biological parents were less likely to belong to either the alcohol or the alcohol and marijuana classes than the non-use group. Results further indicated that youth in classes characterized by the use of multiple substances were more likely to exhibit externalizing problems and internalizing distress than other youth. Findings underscore the importance of identifying heterogeneity even in seemingly homogeneous samples and suggest a number of new directions for future research.
Exploring the physician's role in contraceptive counseling at the time of abortion in the US

Abstract Objective We explored how physicians conceptualize their role in contraceptive counseling at the time of abortion, including identifying clinician attitudes that may lead to patients’ perceptions of contraceptive coercion. Study design We conducted individual semi-structured interviews using questions based on components of the Theory of Planned Behavior. We recruited physician abortion providers using purposeful sampling to attain diversity in practice setting and geographic practice region. We analyzed transcribed interviews using initial and values coding methods. Results We interviewed 39 participants across the United States, who primarily self-reported as White female obstetrician gynecologists (OB/GYNs) aged 25 to 44. Over half of participants practiced in an academic setting. Participants perceived providing patient education and taking a patient-centered approach as part of their role in contraceptive counseling. Participants also believed it was their responsibility to prevent unintended pregnancies and subsequent abortions among their patients. External motivations behind this belief included wanting patients to avoid the challenges of obtaining another abortion, particularly in states with multiple abortion restrictions. Internal motivations included valuing professional goal attainment, discomfort with abortion, and abortion stigma. When physicians counseled about contraception, many expressed preferences toward methods of long-acting reversible contraception (LARC) and an emphasis on contraception provision for adolescents and women with prior abortions. Conclusions Physicians providing abortions strive to use a patient-centered approach to contraceptive counseling. However, many continue to be motivated by the goal of avoiding a subsequent abortion which patients may perceive as coercion towards contraceptive uptake. Implications Considering contraceptive counseling as a means to prevent subsequent abortion may lead to coercive practices, especially with specific patient populations. Moral codes and abortion stigma influence physicians’ counseling practices and physicians must examine their personal values and motivations behind recommending contraception after an abortion.
The effect of solutionizing and artificial aging on the microstructure and mechanical properties in solid-state additive manufacturing of precipitation hardened Al–Mg–Si alloy

Abstract In this study, the effect of post-deposition heat treatments on an Al–Mg–Si alloy processed with additive friction stir deposition (AFS-D), a solid-state additive manufacturing process, is examined. Results reveal that wrought-like microstructure and mechanical properties are achievable in AFS-D builds through the application of a post-deposition heat treatment.
Vitamin C and scar strength: analysis of a historical trial and implications for collagen-related pathologies.

A double-blind controlled trial initiated in 1944 has led to the common narrative that a 10-mg daily vitamin C intake is adequate to prevent and treat impaired wound healing, and by inference, other collagen-related diseases such as heart disease or stroke. The WHO relies on this narrative to set the recommended nutrient intake for vitamin C. This narrative, however, is based on what is known as the eyeball method of data assessment. The 1944 trial published individual participant data on scar strength providing an opportunity to statistically probe the validity of the 10-mg narrative, something which has not yet been done. The findings show that a vitamin C intake that averages to 10 mg/d over a mean follow-up of 11.5 mo was associated with a 42% weakened scar strength when compared with 80 mg vitamin C intake/d (P < 0.001). The observed dose-response curve between scar strength and vitamin C intake suggests that the daily vitamin C intake needed to prevent collagen-related pathologies is in the range recommended by the National Academy of Medicine and the European Food Safety Authority (75 to 110 mg/d), not the WHO recommendation (45 mg/d). The findings also show that a vitamin C intake that averages to 65 mg/d over a mean follow-up of 6.5 mo failed to restore the normal wound-healing capacity of vitamin C-depleted tissues; such tissues had a 49% weaker scar strength when compared with nondepleted tissues (P < 0.05). Thus, average daily vitamin C intakes ∼50% higher than the WHO recommends may fail to treat existing collagen-related pathologies. It is concluded that the prior lack of statistical analyses of a landmark trial may have led to a misleading narrative on the vitamin C needs for the prevention and treatment of collagen-related pathologies.
Beyond the Liver Function Tests: A Radiologist's Guide to the Liver Blood Tests

Liver blood tests (often also known as liver chemistries, liver tests, or the common misnomer liver function tests) are routinely used in diagnosis and management of hepatobiliary disease. Abnormal liver blood test results are often the first indicator of hepatobiliary disease and a common indication for abdominal imaging with US, CT, or MRI. Most of the disease entities can be categorized into hepatocellular or cholestatic patterns, with characteristic traits on liver blood tests. Each pattern has a specific differential, which can help narrow the differential diagnosis when combined with the clinical history and imaging findings. This article reviews the major liver blood tests as well as a general approach to recognizing common patterns of hepatobiliary disease within these tests (hepatocellular, cholestatic, acute liver failure, isolated hyperbilirubinemia). Examples of hepatobiliary disease with hepatocellular or cholestatic patterns are presented with characteristic test abnormalities and imaging findings. The commonly encountered scenario of chronic hepatitis with possible fibrosis is also reviewed, with discussion of potential further imaging such as elastography. The role of liver blood tests and imaging in evaluating complications of hepatic transplant is also discussed. Overall, integrating liver blood test patterns with imaging findings can help the radiologist accurately diagnose hepatobiliary disease, especially in cases where imaging findings may not allow differentiation between different entities. ©RSNA, 2021.
Density prediction in Mars' aerobraking region

Aerobraking at Mars is significantly impacted by the density variability at altitudes between about 100 and 140 km. Density changes can be quite substantial from orbit to orbit and from day to day. Much of this variability arises from tides propagating upward from the lower atmosphere. In this paper we present first results from a method developed to predict density variability in Mars aerobraking region due to this source. It consists of employing physics-based tidal functions to fit tidal temperatures between 60 and 80 km inferred from Mars Climate Sounder measurements on Mars Reconnaissance Orbiter and using these functions to predict the density variations at aerobraking altitudes due to vertical propagation of the fitted tidal components. Validation against densities measured by the Mars Global Surveyor accelerometer suggest that these initial results capture salient features sufficiently well that users may want to incorporate them into operational models.
Genomics and Proteomics of Foodborne Microorganisms

Foods are teeming with microorganisms that may be innocuous, pathogenic threats, spoilage agents, or beneficial microorganisms driving fermentations or acting as biocontrol agents. This chapter outlines the basic concepts underlying genomics, proteomics, and associated technologies. With the number of completely sequenced bacterial genomes increasing rapidly, one powerful approach to defining unique or conserved gene content and understanding how Lactobacillus plantarum microorganisms evolved is comparative genomics, via an in silico analysis. The discipline of functional genomics deals with defining the roles of genes in their appropriate organisms. This chapter utilizes comparative and functional genomics and proteomics to demonstrate the role of SpaC in mucin binding and potentially its importance to the retention of some lactobacilli in the gastrointestinal tract. The principles behind DNA microarray technology make it very applicable to many different uses that include comparative genomics and global gene expression analysis. While the details of the Gad system were elucidated primarily by experiments in Escherichia coli, genomics and bioinformatics have enabled researchers to identify and study the effects of these genes in other organisms. The contribution of genome sequencing and functional genomics has greatly facilitated our understanding of the pathogenicity of Listeria monocytogenes. Differences between the pathogenic and nonpathogenic Listeria species appear most strongly in the secretory proteome.
Making sense of communication associated with artifacts during early design activity

Communication associated with artifacts serves a critical role in the creation, refinement, and selection of conceptual ideas. Despite the close relationship between ideas and surrounding communication, effective integration of these two types of design materials are not well-supported by exiting design tools - resulting in ad-hoc and ineffective strategies for managing communication during the design process. In this paper, we report the results of a contextual inquiry (N=15) aimed at understanding communication practices, its role in the design process, and strategies utilized by designers to manage and utilize communication outcomes in relation to artifacts. Our findings show thatmore than 50% of early design activity consists of three categories of communication (information seeking, brainstorming, and feedback) and communication practice varies as a function of expertise, organizational and social factors. Additionally, novice and freelance designers exhibit greater reliance on online forums to find suitable communication partners to generate and refine ideas whereas experts communicate with other experts or team members for information collection and sharing.
Temporal phase transition in the three-dimensional random-field Ising model.

High-resolution neutron-scattering measurements of the random-field Ising phase-transition behavior in ${\mathrm{Mn}}_{0.75}$${\mathrm{Zn}}_{0.25}$${\mathrm{F}}_{2}$ are reported. An abrupt, apparently discontinuous, transition at ${T}_{\mathrm{N}}(H)$ from history-independent to history-dependent behavior occurs; below ${T}_{\mathrm{N}}(H)$ all states with length scales between the field-cooled value and infinity are stable for indefinite lengths of times; logarithmic decay of the domain size in time may be ruled out. No existing theory accounts for this transition behavior.
“She did what? There is no way I would do that!” The Potential Interpersonal Harm Caused by Mispredicting One’s Behavior

When forecasting their own behavior, people are often inaccurate and tend to predict that they will engage in more socially desirable behavior than they actually do. The problem with inaccurate behavioral forecasts is that they can lead to negative consequences both for the self and for others. One particularly negative consequence may be that such errors can produce overly harsh evaluations and condemnation of others who do not act in a way that most people predict they themselves would act. This paper identifies these common behavioral forecasting errors, why they occur, and the negative interpersonal and unintended, unethical consequences they can have.
How Assigned Faculty Mentors View their Mentoring Relationships: An Interview Study of Mentors in Medical Education

This qualitative study of 29 physician mentors reports their perspectives on mentoring medical students in a well‐respected medical school’s formal, assigned, longitudinal mentoring program that has a curricular component in the second year. Using a phenomenologic inductive approach, common themes identified centered on mentors’ relationships with their students and the characteristics of the relationships. Most mentors said their relationships solidified in the second year, where curricular responsibilities included teaching and evaluation. Mentors saw their roles change, yet relationships continued to develop as mentees advanced through medical school. They were surprised when students sought contact, support, and advice in years three and four of their programs. Mentors worried whether they “did enough” for their students, yet described their experiences and relationships as rewarding. Mentors subsequently found satisfaction in the continuing relationship during the clinical training years. The researc...
Spinal Cord Blood Flow after Ischemic Preconditioning in a Rat Model of Spinal Cord Ischemia

Spinal cord blood flow after ischemic preconditioning is poorly characterized. This study is designed to evaluate spinal cord blood flow patterns in animals after acute ischemic preconditioning. Experiment 1: After a laminectomy and placement of a laser Doppler probe over the lumbar spinal cord to measure spinal cord blood flow, 16 male Sprague-Dawley rats were randomized into two groups: ischemic preconditioning (IPC, n = 8), and control (CTRL, n = 8). Rats in the CTRL and the IPC groups were subjected to 12 min of ischemia directly followed by 60 min of reperfusion. IPC rats received 3 min of IPC and 30 min of reperfusion prior to the 12-min insult period. Experiment 2: After instrumentation, the rats were randomized into three groups: control (CTRL, n = 7), ischemic preconditioning (IPC, n = 7), and time control (TC, n = 4). Rats in the CTRL and the IPC groups were subjected to the same ischemia and reperfusion protocol as above. The TC group was anesthetized for the same time period as the CTRL and the IPC groups, but had no ischemic intervention. Microspheres were injected at baseline and at 15 and 60 min into the final reperfusion. All rats were euthanized and tissue harvested for spinal cord blood flow analysis. In Experiment 1, there was a slight, significant difference in spinal cord blood flow during the ischemic period; however, this difference soon disappeared during reperfusion. In experiment 2, there was no difference in blood flow at any experimental time. The results of these experiments demonstrate that IPC slightly enhances blood flow to the spinal cord during ischemia; however, this effect is not sustained during the reperfusion period.
Gene expression profiling of mouse host response to Listeria monocytogenes infection.

Abstract The purpose of this study was to evaluate gene expression profiles in the liver and blood for prediction of infection severity from Listeria monocytogenes (LM). Mice were injected with medium broth (control) or a nonlethal or lethal dose of LM and sacrificed 6 h later. Gene expression changes were determined using Affymetrix MGU74Av2 GeneChips and confirmed by real-time polymerase chain reaction analysis. We identified discernable genes whose gene expression profiles can be used in pattern recognition to predict and classify samples in differently treated groups, with ≥90% accuracy in liver samples and 80% accuracy in blood at prediction; however, different genes were predictive in each tissue. Our results suggest that gene expression profiling in response to LM in mice may be able to distinguish samples in groups with varying severity of infection and provide information in finding molecular mechanisms and early biomarkers for subsequent conventional clinical endpoints.
The effects of potassium on the positive inotropic action of ouabain.

Abstract The effects of varying concentrations of extracellular potassium on the positive inotropic action of ouabain were studied in an isolated muscle preparation of guinea pig right ventricles. The isometric tension and peak dF dt were significantly greater at a concentration of extracellular potassium of 2 mEq. per liter than at the normal concentration of 5 mEq. per liter in control studies. There was no significant difference between the tensions or maximum dF dt at 5 and 10 mEq. per liter potassium. Ouabain produced a significant increase in tension and peak dF dt at all concentrations of potassium. The ouabain-induced increase in tension at 2 mEq. per liter potassium was not significantly different from that at 5 mEq. per liter, but the level of attained tension and dF dt were greater at 2 mEq. per liter since the base-line tension and dF dt at this concentration were greater. The positive inotropic effects of ouabain and low concentrations of extracellular potassium were, therefore, additive. At a potassium of 10 mEq. per liter the increment in tension and peak dF dt produced by ouabain was significantly less than at 5 mEq. per liter, and the absolute tension at 10 mEq. per liter was also significantly smaller. Possible mechanisms to explain these findings are considered.
An air-drying procedure for mammalian male meiotic chromosomes, following softening in gluconic acid and cell separation by an ethanol-acetic mixture.

A I cm3 sample of tubules from testes is placed in 5 ml of 0.7% Na-citrate for 20-30 min, then 5 ml of glacial acetic acid is added, mixed well, and allowed to stand for 30 min. The mixture is centrifuged, the supernatant removed, and 3 ml of 3 M gluconic acid is mixed with the tissue and allowed to act for 3 hr. The gluconic acid is removed with a pipette and the tissue is suspended in 5 ml of a freshly made 1:1 absolute ethanol-glacial acetic acid mixture. The tissue is drawn into and discharged from a syringe several times through an 18, a 20, and finally a 22 gauge needle to separate and suspend the cells. The cells are centrifuged and resuspended several times in fresh fixative to remove the gluconic acid. Finally, the cells are suspended in sufficient fixative to give a smear of suitable density, and air-dried preparations are made, or the suspension may be stored at 0-5 C for several days. The cells can be stained by any of the usual stains for chromosomes. This technique results in the improved sp...
Quantitative Golgi study of anatomically identified subdivisions of motor thalamus in the rat.

A Golgi study of neurons in the ventroanterior-ventrolateral complex (VAL) and ventromedial (VM) nucleus in the dorsal thalamus of rats was performed. To facilitate the delineation of subdivisions of these nuclei, some animals received injections of horseradish peroxidase (HRP) into the afferent and efferent fields of VAL and VM, and alternate sections were processed for the histochemical detection of HRP. As an adjunct to subjective observations, a multivariate statistical analysis of morphometric variables was performed to provide an objective assessment of neuronal morphology. All Golgi-stained neurons in VAL and VM were tentatively identified as projection neurons; no cells with morphological features commonly ascribed to thalamic interneurons were impregnated. Four classes of morphologically distinct neurons were identified in VAL. Type 1 neurons, the most commonly impregnated cell, were found throughout the extent of VAL and resembled “tufted” or “multipolar bush” neurons described previously in many thalamic nuclei. The remaining three neuronal types differed in a number of morphometric parameters and were differentially distributed throughout VAL. Type 2 neurons, distinguished in part by dendritic spine morphology and elongated bipolar dendritic fields, were found only in the rostral sector of the dorsal division of VAL (VALD). Type 3 neurons, characterized by a large and evenly distributed dendritic field, were situated in rostral VAL (all subdivisions). Type 4 neurons had small soma and dendritic dimensions and were located in the ventromedial aspect of the ventral division of VAL (VALV) adjacent to VM. In contrast, the vast majority of neurons in VM were considered to be a single morphological class (similar in form to type 4 neurons in VAL), although a rarely impregnated second type of neuron was also observed. The apparent scarcity of interneurons in VAL and VM is consistent with previous evidence that the synaptic organization of motor thalamus in the rat is markedly different from that of higher-order mammals. Speculation about the functional attributes of the neuronal types in VAL and VM is necessarily restricted to considerations of afferent and efferent relations, since “motor modality” functions of neurons in these nuclei have yet to be elucidated.
Uses of violence

The threat of violence, and the occasional outbreak of real violence (which gives the threat credibility), are essential elements in conflict resolution not only in international, but also in national communities.1 Individuals and groups, no less than nations, exploit the threat as an everyday matter. This fact induces flexibility and stability in democratic institutions and facilitates peaceful social change. I refer not only to the police power of the state and the recognized right of self-defense, but also to private individual or group violence, whether purposive or futile, deliberate or desperate. Violence and the threat of violence, far from being meaningful only in international politics, is an underlying, tacit, recognized, and omnipresent fact of domestic life, of which democratic politics is sometimes only the shadow-play. It is the fact that instills dynamism to the structure and growth of the law, the settlement of disputes, the processes of accommodating interests, and that induces general respect for the verdict of the polls. An effort by the state to obtain an absolute monopoly over violence, threatened or used on the behalf of private interests, leads inexorably to complete totalitarian repression of all activities and associations which may, however remotely, create a basis of antistate action. A democratic system preserves he threat of violence, and the occasional utbreak of real violence (which gives the reat credibility), are essential lements conflict resolution n t o ly in interna-
Short-term plasticity and auditory processing in the ventral cochlear nucleus of normal and hearing-impaired animals

The dynamics of synaptic transmission between neurons plays a major role in neural information processing. In the cochlear nucleus, auditory nerve synapses have a relatively high release probability and show pronounced synaptic depression that, in conjunction with the variability of interspike intervals, shapes the information transmitted to the postsynaptic cells. Cellular mechanisms have been best analyzed at the endbulb synapses, revealing that the recent history of presynaptic activity plays a complex, non-linear, role in regulating release. Emerging evidence suggests that the dynamics of synaptic function differs according to the target neuron within the cochlear nucleus. One consequence of hearing loss is changes in evoked release at surviving auditory nerve synapses, and in some situations spontaneous release is greatly enhanced. In contrast, even with cochlear ablation, postsynaptic excitability is less affected. The existing evidence suggests that different modes of hearing loss can result in different dynamic patterns of synaptic transmission between the auditory nerve and postsynaptic neurons. These changes in dynamics in turn will affect the efficacy with which different kinds of information about the acoustic environment can be processed by the parallel pathways in the cochlear nucleus.
NEW METHOD FOR EXTRACTION OF MILK PHOSPHOLIPIDS.

Abstract The whole milk sample was compounded with silicic acid, the mixture placed in a glass chromatographic column, and the phospholipid fraction eluted with 20% (v/v) formic acid in ethyl ether. Lipid phosphorus analysis and thin-layer chromatography were used for the comparison of phospholipid recovery from 10-ml aliquots of milk by each of three methods—the new, the Mojonnier, and the modified Mojonnier (1.5% NaCl added to the milk sample before a Mojonnier extraction). Five trials verified that the modified Mojonnier method and new silicic acid column chromatographic (SACC) method recovered 10.2 and 12.2 mean per cent, respectively, more lipid phosphorus than the conventional Mojonnier procedure. When aliquot samples from the phospholipid extracts recovered by the three methods were compared by thin-layer chromatography, minor differences were evident in the lipid patterns, notably in improved recovery of a component corresponding to phosphatidyl serine by the SACC method and in superior recovery of lysophosphatides by the Mojonnier and modified Mojonnier methods.
Management of spontaneous nontraumatic intracranial hemorrhage

Intracerebral hemorrhage (ICH) is one of the most devastating subtypes of stroke and is characterized by spontaneous extravasation into the parenchymal tissue of the brain. Although advances in critical care have improved, there is no intervention currently available that has shown to alter the outcome of patients who have suffered acute ICH. Therefore, management is largely supportive. Treatment strategies are aimed at limiting hematoma enlargement, seizures, and cerebral edema, as well as other ICU-related complications such as deep venous thrombosis, hyperglycemia, and fever. This review will outline the key pharmacological management strategies in patients with ICH and highlight the most current American Heart Association/American Stroke Association (AHA/ASA) guidelines for management published in 2007.
7α and 7β‐Hydroxycholesterols Formed in a Dry Egg Nog Mix Exposed to Fluorescent Light

Light-induced generation of two cholesterol oxidation products, 7α- and 7β-hydroxycholesterol, was measured in an egg nog mix using an improved isolation procedure and high performance liquid chromatography (HPLC). Dry egg nog mix was exposed continuously to fluorescent light at room temperature for 90 days. The 7α-hydroxycholesterol was formed in consistently greater amounts than the 7β-form. Amounts of both forms increased for up to 80 days (23 ± 2°C), then declined. Mix stored in the dark did not contain detectable amounts of 7α- or 7β-hydroxycholesterol. Purification techniques enabled HPLC quantification of cholesterol oxidation products in a food.
Cyberbullying: Prevention and Intervention to Protect Our Children and Youth

Bullying has long been of concern to school officials and parents alike. Bullying, which is a type of aggressive behavior, has now entered the electronic age in the form of cyberbullying (e.g., e-mails, text messages, profile sites). Cyberbullying is especially insidious because it affords a measure of anonymity and the opportunity to reach a much larger number of victims without a significant threat of punishment. In this article, the authors discuss efforts to combat cyberbullying that include prevention and intervention programs at the community, school, and family levels. The authors point out that the majority of U.S. states have written legislation to address bullying and cyberbullying and that many schools have established policies that prohibit electronic bullying and developed consequences for doing so. Last, the authors discuss a number of antibullying curricula and mediated programs, software packages, and intervention strategies for the school and home designed to help protect children and ado...
The relationships among trauma, stress, ethnicity, and binge eating.

The present study investigated whether trauma, stress, and discriminatory experiences influenced binge eating among 93 African American and 85 Caucasian women. Trauma and stress were significantly related to binge eating for both groups, although the stress‐binge eating relationship was stronger for Caucasian women. Ethnicity did not moderate the relationship between trauma and binge eating, but did moderate the stress‐binge eating relationship. Finally, the hypothesis that trauma and stress would influence binge eating through their effects on function of eating was partially supported; the relationship between stress and binge eating was partially mediated by function of eating among Caucasian women. The implications of these findings for our understanding of binge eating are discussed.
Evidence for the secretion of thyrocalcitonin at normal and subnormal plasma calcium levels

The role of the thyroid in response to calcium challenge was examined. A continuous calcium load of 2 mg/hr for 4 hr was delivered by peritoneal lavage using a 12.0–12.5 mg/100 ml calcium lavage rinse in rats made hypocalcemic by prior thyroparathyroidectomy and/or parathyroidectomy. The bones of these animals had been labeled 1–2 weeks earlier with appropriate radioisotopes (86Sr, 45Ca). Although only slight differences in both plasma calcium and total transfer of calcium out of lavage fluid could be observed between the 2 groups, a marked difference developed in the amount of radioisotopetransferred to lavage fluid. After 3–4 hr, animals with functional thyroids transferred 25% less radioactivity into the lavage fluid than animals without these glands. Control studies indicated that thyroxine was not responsible for this particular effect. This evidence has been interpreted as a demonstration that thyrocalcitonin secretion had been elicited by the calcium challenge. In addition, because plasma calcium l...
A semipolar (10-1-3) InGaN/GaN green light emitting diode

We demonstrate the first green InGaN/GaN light emitting diode (LED) grown on a planar semipolar $$\left( {10\overline 1 \overline 3 } \right)$$ GaN template. The LED structure is grown by metalorganic chemical vapor deposition (MOCVD), and the 20 μm-thick, specular and optically transparent template is grown by hydride vapor phase epitaxy (HVPE). The fabricated devices have a peak emission wavelength of ~525 nm and demonstrate rectifying behavior, with a low operating voltage of 3.25 V at 20 mA. We observe a small ~7 nm blue-shift in the peak emission wavelength during electroluminescence measurements, over the range 20 to 250 mA. We also see an almost linear increase in the output power from 5 mA to 250 mA, with no appreciable decrease in the external quantum efficiency over the same range. Additionally, we observe evidence of polarization anisotropy in the emission from the semipolar green LEDs.
Cloud properties and associated radiative heating rates in the tropical western Pacific

[1] Calculations of radiative flux profiles require measurements of thermodynamic and cloud properties (temperature, humidity, liquid and ice water content). Instruments capable of making these measurements have only recently become available. The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program operates a comprehensive set of atmospheric remote sensing instruments at sites around the world, including three in the tropical western Pacific region. We have processed several months of ARM observations from two of these sites, Manus and Nauru, to calculate time series of vertical cloud property profiles and associated radiative fluxes and heating rates. Maxima in cloud occurrence are found in the boundary layer and the upper troposphere at both sites. Manus, which was much more convectively active than Nauru during the study period, also exhibits a midlevel cloud feature near the melting level. The two sites exhibit very different diurnal cycles. Manus experiences an afternoon maximum in high clouds while Nauru experiences a weak afternoon minimum. Nauru experiences a strong afternoon maximum in boundary layer clouds. Calculated fluxes at the surface and the top of the atmosphere are found to be in reasonable agreement with measurements. Below 15 km, radiative processes lead to cooling in the average profile, with local maxima near the surface and approximately 8 km. On average, high and midlevel clouds have a net warming effect though not enough to offset the clear-sky cooling. The prevalent boundary layer clouds at Nauru have a net cooling effect in and above the cloud layer and a net warming below. This data set will be an important tool for describing radiative processes in the tropics and assessing the simulation of these processes in dynamical models.
Universality of magnetic tricritical points

A recent renormalization-group treatment of metamagnetic tricritical behavior is applied to more general systems with competing ferromagnetic and antiferromagnetic interactions. In particular, it is found that the next-nearest-neighbor model treated numerically by Stanley and Harbus, and by Landau, should have classical tricritical exponents (up to logarithmic corrections), as found previously for layered metamagnets but in disagreement with conclusions initially drawn from the numerical evidence.
Protection of estrogenic hormones by ascorbic acid during chromatography.

Abstract Oxidative decomposition of phenolic hormones during thin-layer chromatography can be avoided by the incorporation of ascorbic acid into the plates. The application of this technique to the purification of urinary extracts is described.
Are some major in vivo effects of gold related to microenvironments of decreased selenium

Gold interacts with selenium in vivo, and the normal distribution of selenium among tissues and subcellular compartments changes. Literature evidence shows that many of the effects of gold compounds on the polymorphonuclear neutrophil, macrophage, and lymphocyte cellular components of the immune system are similar to effects observed in these cellular components in selenium-deficient animals. Affected by these two metals are immune functions related to phagocytic cell migration, phagocytosis, microbial killing, lymphocyte mitogenesis/DNA synthesis, arachidonic acid metabolism/prostaglandin synthesis, and immunoglobulin production. The interaction of gold with selenium in vivo may be responsible for some of the multiparameter-based actions of gold compounds used in the treatment of inflammatory diseases such as rheumatoid arthritis. One mechanism by which gold exerts its clinical effects may be related to its interaction with selenium to produce, in specific microenvironments, decreased levels of this essential trace element.
Matrix Metalloproteinase Inhibitors: Do They Have a Place in Anticancer Therapy?

Matrix metalloproteinases (MMPs) are a family of enzymes involved in degradation of extracellular matrix. An imbalance between MMPs and naturally occurring MMP inhibitors may cause excess extracellular matrix destruction, allowing cancer cells to invade surrounding tissues and metastasize, and permitting angiogenesis to occur. Inhibition of certain key MMPs may prevent angiogenesis, tumor growth, invasion, and metastasis. Gelatinases MMP-2 and MMP-9 are expressed during carcinogenesis and angiogenesis. Synthetic MMP inhibitors were designed to target these enzymes and potentially prevent the tumor growth and metastases associated with cancer.
Chemometric Data Analysis for Deconvolution of Overlapped Ion Mobility Profiles

We present the details of a data analysis approach for deconvolution of the ion mobility (IM) overlapped or unresolved species. This approach takes advantage of the ion fragmentation variations as a function of the IM arrival time. The data analysis involves the use of an in-house developed data preprocessing platform for the conversion of the original post-IM/collision-induced dissociation mass spectrometry (post-IM/CID MS) data to a Matlab compatible format for chemometric analysis. We show that principle component analysis (PCA) can be used to examine the post-IM/CID MS profiles for the presence of mobility-overlapped species. Subsequently, using an interactive self-modeling mixture analysis technique, we show how to calculate the total IM spectrum (TIMS) and CID mass spectrum for each component of the IM overlapped mixtures. Moreover, we show that PCA and IM deconvolution techniques provide complementary results to evaluate the validity of the calculated TIMS profiles. We use two binary mixtures with overlapping IM profiles, including (1) a mixture of two non-isobaric peptides (neurotensin (RRPYIL) and a hexapeptide (WHWLQL)), and (2) an isobaric sugar isomer mixture of raffinose and maltotriose, to demonstrate the applicability of the IM deconvolution.
Magneto-optical circulator in two-dimensional photonic crystals

We propose a systematic approach to miniaturize magneto-optical device down to a single wavelength scale through the use of photonic crystal resonances. The nonreciprocal transport, typically found in magneto-optics, is highly enhanced in structures with strong field localization. The devices are magnetically biased along the out-of-plane direction (Voigt configuration). An optimized magnetic domain design maximally couples the standing-wave eigenstates in the resonance. As a conceptual demonstration, we demonstrate the design guideline in two-dimensional photonic crystal cavities, which can be readily extended into designing two-dimensional slab structures with the same functionality. A three-port junction circulator containing bismuth-iron-garnet is modeled with finite-difference time-domain schemes and demonstrates a 30dB-isolation bandwidth well over 100GHz.
Ferrate(VI) Oxidation of Hydrogen Sulfide

The rates of oxidation of hydrogen sulfide with Fe(VI) were made anaerobically as a function of pH (7−12) and temperature (5−15 °C). The reaction was found to be first order for each reactant. The rates decrease with an increase in pH. The energy of activation was found to be 30.1 ± 4.9 kJ mol-1 at pH = 12. When the concentrations of [H2S]T ([H2S] + [HS-]) are in excess, the ratio of [H2S]T consumed to [Fe(VI)] consumed was 1.51 ± 0.14 at pH = 7.0 and 2.50 ± 0.13 at pH = 9.0 and 11.3. Thiosulfate was the main product at pH = 7.0; sulfite, thiosulfate, and sulfate were identified as the products of the reactions at pH = 9.0 and 11.3. In an excess of [Fe(VI)] over [H2S]T, the hydrogen sulfide is fully oxidized to sulfate. A mechanism in which Fe(VI) oxidizes H2S by a one-electron process is proposed. Experiments were conducted to test the Fe(VI) removal efficiency of sulfide in groundwater and wastewater. The results indicate that Fe(VI) can be used as an effective oxidant to remove hydrogen sulfide from wa...
A description language for engineering of complex real-time systems

Typical in modern complex real-time applications are (1) integration of lar ge systems, as well as development of new systems and subsystems, (2) complex, often conflicting, functional and non-functional objectives, and (3) a significant degree of distribution and parallelism. The article takes a particular approach to viewing such applications, and describing them in a new language, called CaRT-Spec. While CaRT-Spec addresses many complex application objectives, the focus of our presentation is on functionality and timeliness, i.e. schedulability.
Phase contrast techniques for wavefront sensing and calibration in adaptive optics

The wavefront sensor is the most critical component of an adaptive optics (AO) system. Most astronomical systems use one of a small number of alternatives, notably the Shack-Hartmann or the curvature sensor; these are sensitive to the first and second derivative of the wavefront phase, respectively. In this paper, we explore a novel adaptation of the phase-contrast technique developed for microscopy by Zernike to measure phase directly, and show that it is potentially useful in astronomical adaptive optics, both for closed-loop wavefront sensing and for off-line calibration of the system PSF. The phase-contrast WFS should enjoy an advantage in lower read noise, as well as a natural match to the piston-type deformable mirror actuators commonly in use with most current Shack-Hartmann systems, and favorable error propagation during wavefront reconstruction. It appears that it might be possible to implement versions with the reasonably broad spectral bandwidth desired for astronomical applications, and to integrate them with relatively minor modifications into existing AO system architectures.
Inhibition of topoisomerase II by liriodenine

The cytotoxic oxoaporphine alkaloid liriodenine, isolated from Cananga odorata, was found to be a potent inhibitor of topoisomerase II (EC 5.99.1.3) both in vivo and in vitro. Liriodenine treatment of SV40 (simian virus 40)-infected CV-1 cells caused highly catenated SV40 daughter chromosomes, a signature of topoisomerase II inhibition. Strong catalytic inhibition of topoisomerase II by liriodenine was confirmed by in vitro assays with purified human topoisomerase II and kinetoplast DNA. Liriodenine also caused low-level protein-DNA cross-links to pulse-labeled SV40 chromosomes in vivo, suggesting that it may be a weak topoisomerase II poison. This was supported by the finding that liriodenine caused topoisomerase II-DNA cross-links in an in vitro assay for topoisomerase II poisons. Verapamil did not increase either liriodenine-induced protein-DNA cross-links or catalytic inhibition of topoisomerase II in SV40-infected cells. This indicates that liriodenine is not a substrate for the verapamil-sensitive drug efflux pump in CV-1 cells.
On the relationship of semiconductor compound properties and the average heats of atomisation

Abstract The average heat of atomisation of semiconductor compounds, as computed from the heats of atomisation of the elements, is proposed as the basis for correlating the physical properties of these compounds and in particular the corresponding energy gaps. Inconsistencies encountered by employing other criteria (electronegativity differences, heats of formation etc.) in correlating semiconductor properties are pointed out and the general applicability of average heats of atomisation as reflecting the relative bond strength is illustrated. The average heat of atomisation is rather unique in correlating the properties of ternary and higher order semiconductor compounds.
Common regions of dorsal anterior cingulate and prefrontal-parietal cortices provide attentional control of distracters varying in emotionality and visibility

Top-down attentional control is necessary to ensure successful task performance in the presence of distracters. Lateral prefrontal cortex, parietal cortex and anterior cingulate cortex have been previously implicated in top-down attentional control. However, it is unclear whether these regions are engaged independent of distracter type or whether, as has been suggested for anterior cingulate cortex, different regions provide attentional control over emotional versus other forms of salient distracter. In the current task, subjects viewed targets that were preceded by distracters that varied in both emotionality and visibility. We found that behaviorally, the presence of preceding distracters significantly interfered with target judgment. At the neural level, increases in the emotional and visual saliency of distracters were both associated with increased activity in proximal regions of prefrontal, parietal and cingulate cortex. Moreover, a conjunction analysis indicated considerable overlap in the regions of prefrontal, parietal cortex and anterior cingulate cortex responding to distracters of increased emotionality and visibility.
The Cultural Authentication of Ribbon: Use and Test of a Concept:

The concept of cultural authentication was utilized to organize research on the assimilation of European-produced silk ribbon into the material culture of native American tribes of the Great Lakes region from the mid-18th to mid-19th centuries. Conversely, the ethnohistorical data on ribbon were applied to the concept of cultural authentication as a test of its utility as a cross-cultural theoretical construct. While the findings suggest that further elaboration of the level of "characterization" is necessary, the concept of cultural authentication is affirmed as a means to provide a structure for the inquiry into and the interpretation of the transfer of cultural phenomena such as textiles and clothing.
The effect of air exposure on palladium–copper composite membranes

Abstract It was found that when electrolessly deposited thin Pd and Pd–Cu membranes were exposed to air at temperatures above 350 °C, their H 2 flux increased substantially immediately after the air exposure, then decreased to a new steady-state value. While this was a quasi-reversible change for the H 2 flux, the flux of insoluble species, such as N 2 , irreversibly increased with every air exposure but by a much smaller extent. The extent of these changes was found to be dependent on the exposure time and the temperature of the tests. Thus, we decided to investigate the effect of gas exposures on the properties of these materials. Palladium and palladium–copper films, prepared by electroless deposition on ceramic supports, and commercial foils were exposed to air, hydrogen and helium at 500 and 900 °C for times varying from 1 h to 1 week with the objective of determining the effect of the different exposure conditions on the surface morphology, the flux of different penetrants and the crystalline structure of the materials. Atomic force microscopy (AFM) and X-ray diffraction (XRD) were used to study the changes occurring in the films under those conditions. It was observed that the exposure of both the electroless films and the foils to hydrogen and air markedly modified their surface morphology. The hydrogen exposure tended to smooth the surface features whereas the oxygen exposure created new surface features such holes and large peaks. Additionally it was found that the air exposure produced some oxidation of the film to create PdO. These results suggested that a common hypothesis stating that air oxidation just cleans the surface of the membrane might not be sufficient to explain all of those changes. A contributing effect of air exposure may be the increase in surface area due to the formation of palladium oxide. However, the extent of the surface area increase was insufficient to explain the increase in steady-state H 2 flux.
College Student Migration and Human Capital Theory: A Research Note.

The present note offers improvements on previous work by Tuckman (1970) and Mixon (1992a, b) that describes college student migration as a from of human capital investment. WHile previous work employed macro-data and single equation estimation techniques, the present study utilizes a large institution-level data set of four-year colleges in the US and two-stage least-squares estimation to account properly for the simultaneity within the modeling process. This study suggests that small class sizes, college selectivity, successful athletic programmes, the availability of diverse cultural alternatives, and highly qualified and productive faculty are important in attracting non-resident students to colleges and universities across states. In summary, this research note lends support to human capital theory and offers an alternative to the screening hypothesis.