cssi/SciSciGPT-SciSciNet huggingface dataset:
RNA interference as a promising strategy for plant disease management

Abstract RNA interference (RNAi) in plant disease management is a novel gene silencing tool that uses several types of double-stranded RNAs (dsRNAs) to knock down the genes either at transcriptional or posttranscriptional level aimed at sequence-specific degradation of phytopathogen’s gene/s or gene/s that code for suppressor molecules to combat negative effects of plant pathogens in crop production. Transformative and nontransformative approaches viz. host-induced gene silencing, spray-induced gene silencing (SIGS), and virus-induced gene silencing have been exploited to elicit RNAi mechanism, and recent strategy SIGS uses exogenous applications of naked in vitro-synthesized or crude dsRNAs. Disease control via RNA silencing in plant disease management has broadly been studied for viral and fungal diseases, and very few investigations have been reported against bacterial diseases. This chapter summarizes the potential of RNAi technology in plant disease management to control major phytopathogens. It also critically and comprehensively examines various methods used for induction of RNAi mechanism and current applications of such strategies of RNAi in different crop systems against plant pathogens. Therefore it can be concluded that RNA silencing is a promising and effective tactic in managing phytopathogens without causing any deleterious effects on the environment.
A Simple Scaling Approach to the Spontaneous Clearing Time of Water Block

Hydraulic fracturing causes water to invade reservoir rock. This invaded water is called a water block as it lowers the effective permeability of the rock to oil. Field and laboratory results show that the water block is temporary. We hypothesize that (a) the clearing is caused by capillary-dominated advection of water, and (b) the clearing takes place when the water saturation drops at the fracture face. We test this hypothesis with laboratory experiments, analytic solutions, and numerical simulations to a capillary-driven model. In particular, we determine how the clearing time scales with the permeability of the rock and the amount of water invaded, and this scaling matches experimental observations. From this match, we develop an equation that estimates clearing time and test how the leading coefficient of this equation depends on rock constitutive parameters (e.g., capillary pressure, relative permeability).
Talk radio’s America: how an industry took over a political party that took over the United States: by Brian Rosenwald, Cambridge, MA, Harvard University Press, 358 pp., $29.95 (hardback), ISBN-13: 978-0674185012

Brian Rosenwald opens up a historical perspective on both the political climate over the past quarter-century and the media landscape that contributed to the rise of Donald Trump. His exhaustive re...
A curse upon the nation: race, freedom, and extermination in America and the Atlantic World: by Kay Wright Lewis, Athens, GA, The University of Georgia Press, 2017, 281 pp., $64.00 (hardback), ISBN: 978-0820351278

When organizers of groups like Black Lives Matter protest the killing of young Black men, they are protesting a practice that is older than the nation itself, the attempt to exterminate the entire ...
Bonds of sweetness: A political and intellectual history of citrus circulations across the Western Mediterranean during the Late Renaissance.

El present article analitza com les converses politiques i intel·lectuals sobre els intercanvis de fruita van afectar les relacions entre poder i coneixement a la Mediterrania occidental durant el Renaixement tarda. S’hi argumenta que les xarxes d’erudits van promoure el desenvolupament de la diplomacia informal a traves de l’us del significat paradoxal dels citrics nouvinguts per via de les monarquies iberiques, i que aquesta comunicacio politica va estar articulada al voltant de conceptes com la tolerancia i la dolcor. Aixi mateix, es demostra que a Espanya, Portugal i Roma les practiques politiques i els discursos sobre citrics van alimentar les lluites pel control de la cristiandat en un periode que va estar marcat per continues guerres i debats sobre l’estatus de les minories religioses.
Flexible optical imaging band system for the assessment of arthritis in patients with systemic lupus erythematosus

We have developed a flexible optical imaging system (FOIS) to assess systemic lupus erythematosus (SLE) arthritis in the finger joints. While any part of the body can be affected, arthritis in the finger joints is one of the most common SLE manifestations. There is an unmet need for accurate, low-cost assessment of lupus arthritis that can be easily performed at every clinic visit. Current imaging methods are imprecise, expensive, and time consuming to allow for frequent monitoring. Our FOIS can be wrapped around joints, and multiple light sources and detectors gather reflected and transmitted light intensities. Using data from two SLE patients and two healthy volunteers, we demonstrate the potential of this FOIS for assessment of arthritis in SLE patients.
The bacterial protein Hfq: Stable modifications and growth phase-dependent changes in SPAM profiles.

Abstract In bacteria transcription is coupled to translation, and while it is broadly accepted that transcription–translation complexes (TTCs) are formed in growing bacterial cells, the exact spatial organization of these macromolecular assemblies is not known with certainty. Recent studies indicated the formation of orderly cytosolic superstructures in growing E. coli cells. The bacterial nucleic acid (NA)-binding protein Hfq has been shown to function at the interface of RNA synthesis–degradation machinery; multiple, independent studies link Hfq to orderly cytosolic assemblies. In this work, using fast cell lysis/2D-PAGE and in vitro reconstitution analyses we studied the Hfq modifications and small protein-associated molecules (SPAM). We demonstrate that native Hfq carries stable modifications and simulate 2D patterns of native Hfq–SPAM complexes in reconstitution experiments with purified Hfq and synthetic NA probes. We also demonstrate that genetically engineered Hfq lacking the conserved arginine residues positioned near the rim of the disc formed by the subunits’ N-terminal domains binds DNA with a reduced affinity in comparison with wild-type Hfq. These results are consistent with the proposed Hfq-mediated DNA remodeling and point to the involvement of this patch of conserved arginines in interactions with DNA.
A Quasi-Newton method for physically-admissible simulation of Poiseuille flow under fracture propagation.

Coupled hydro-mechanical processes are of great importance to numerous engineering systems, e.g., hydraulic fracturing, geothermal energy, and carbon sequestration. Fluid flow in fractures is modeled after a Poiseuille law that relates the conductivity to the aperture by a cubic relation. Newton's method is commonly employed to solve the resulting discrete, nonlinear algebraic systems. It is demonstrated, however, that Newton's method will likely converge to nonphysical numerical solutions, resulting in estimates with a negative fracture aperture. A Quasi-Newton approach is developed to ensure global convergence to the physical solution. A fixed-point stability analysis demonstrates that both physical and nonphysical solutions are stable for Newton's method, whereas only physical solutions are stable for the proposed Quasi-Newton method. Additionally, it is also demonstrated that the Quasi-Newton method offers a contraction mapping along the iteration path. Numerical examples of fluid-driven fracture propagation demonstrate that the proposed solution method results in robust and computationally efficient performance.
Thermite reactions with oxides of iron and silicon during combustion of magnesium with lunar and Martian regolith simulants

Abstract It has been shown recently that mixtures of JSC-1A lunar regolith simulant with magnesium are combustible. Thermite-type reactions in these mixtures could be used for in situ production of construction materials on the Moon. Because of complex composition of lunar regolith, however, the mechanisms of these reactions are not well understood. Also, for Mars mission applications, it is important to explore the possibility of using Martian regolith in such mixtures. In the present paper, combustion of two Martian regolith simulants (JSC-Mars-1A and Mojave Mars) with magnesium is studied using thermodynamic calculations and combustion experiments. To understand the reaction mechanisms in these mixtures as well as in the mixtures of JSC-1A lunar regolith simulant with magnesium, thermoanalytical experiments are also conducted. It has been shown that the Martian regolith simulants form combustible mixtures with magnesium. The measured combustion temperatures and identified product compositions are in reasonable agreement with thermodynamic predictions. The mixtures of JSC-Mars-1A with magnesium at 20–30 wt% Mg exhibit higher temperatures and burn more vigorously than mixtures based on Mojave Mars, which is explained by the higher content of iron oxide in JSC-Mars-1A. For Mojave Mars, combustion is accompanied by oscillations in the front motion and by the formation of a layered structure of the product. This effect is more significant at lower concentrations of Mg. Thermoanalytical studies have shown that iron oxide plays a dominant role in the combustion of JSC-Mars-1A simulant with magnesium. However, Mg/SiO2 mixture ignites at a temperature lower by approximately 100 °C than for Mg/Fe2O3. For Mojave Mars material and JSC-1A lunar regolith simulant, which include more silica and less iron oxide, silica exhibits a significant effect on the combustion, promoting reactions at lower temperatures.
Anticipating Intervention: Third Party Support and the Onset of Civil War

A large literature analyzing the sources and consequences of civil war intervention demonstrate both that it is a patterned, predictable event and that it is particularly consequential for civil war states. Interventions are associated with longer, bloodier civil wars. Such civil wars are more likely to recur. If academic researchers can uncover patterns indicating which civil wars experience interventions, surely political leaders can as well. Thus, they must anticipate the subjective probabilities their struggles will involve third party interventions when planning their civil wars. The correlates of civil war intervention should then influence the probability of civil war onset. Although a few studies have recognized this logical connection, no one has yet investigated empirical patterns between intervention and onset. We undertake such analysis here, and find strong support for the expectation that when the estimated probability of intervention is high, civil wars are less likely to occur.
The Contribution of Teachers' Emotional Support to Children's Social Behaviors and Self-Regulatory Skills in First Grade

The present observational study used hierarchical linear modeling to examine predictors of children's social and self-regulatory outcomes in first-grade classrooms. Specifically, goals were the fol...
Steroid-Protein Interactions XXVI. STUDIES ON THE POLYMERIC NATURE OF THE CORTICOSTEROID-BINDING GLOBULIN OF THE RABBIT

Abstract The rabbit corticosteroid-binding globulin (CBG), fully saturated with corticosteroid, was separated by Sephadex G-200 filtration into a corticoid-binding monomer and a steroid-free tetramer. Polymerization could be enhanced by removal of the steroid from CBG or by prolonged storage. Partial depolymerization and reactivation of the inactive tetramer was obtained by incubation with a relatively large quantity of cortisol; the restored binding affinity was associated with the monomeric species. Equilibrium ultracentrifugation according to Yphantis indicated paucidispersity of the CBG; the predominant component had a molecular weight of 34,700 ± 1,200. The approach to sedimentation equilibrium technique of Archibald gave a weight-average molecular weight of 61,400 ± 1,600, suggesting a mixture of approximately 75% monomer and 25% tetramer. A single broad band was observed in sodium dodecyl sulfate electrophoresis; two closely adjacent bands resulted when mercaptoethanol treatment was included. The corresponding apparent molecular weight, based on calibration with carbohydrate-free proteins was approximately 40% greater than that obtained by the Yphantis method. Similar deviations occurred with α1-acid glycoprotein and ovomucoid. We attribute these deviations to abnormal behavior of glycoproteins in the polyacrylamide electrophoresis. The results are compatible with a molecular weight of approximately 35,000 for the monomeric rabbit CBG.
Congress, the Courts, and the Army Corps: Siting the First Offshore Wind Farm in the United States

Once considered an issue only for environmentalists, renewable energy has entered the mainstream dialogue as fears of climate change, acid rain, and dependence on foreign sources of fuel become more prevalent. There is now broad support for adding renewable energy, including wind power, into our nation's fuel mix. Technological advances have allowed wind power to compete with traditional fossil fuels and lessen other potentially harmful impacts. Land-based wind power is widespread globally, and offshore wind facilities have been operating in Europe for over a decade. While there are currently several proposals for large-scale offshore wind farms in the United States, no such facilities have been sited to date. An intense legal controversy has emerged, stemming from a proposal to site a wind farm off the coast of Massachusetts. The outcome of this dispute will have important consequences for future proposals for offshore wind farms.
Aldosterone-stimulating somatic gene mutations are common in normal adrenal glands

Primary aldosteronism (PA) represents the most common cause of secondary hypertension, but little is known regarding its adrenal cellular origins. Recently, aldosterone-producing cell clusters (APCCs) with high expression of aldosterone synthase (CYP11B2) were found in both normal and PA adrenal tissue. PA-causing aldosterone-producing adenomas (APAs) harbor mutations in genes encoding ion channels/pumps that alter intracellular calcium homeostasis and cause renin-independent aldosterone production through increased CYP11B2 expression. Herein, we hypothesized that APCCs have APA-related aldosterone-stimulating somatic gene mutations. APCCs were studied in 42 normal adrenals from kidney donors. To clarify APCC molecular characteristics, we used microarrays to compare the APCC transcriptome with conventional adrenocortical zones [zona glomerulosa (ZG), zona fasciculata, and zona reticularis]. The APCC transcriptome was most similar to ZG but with an enhanced capacity to produce aldosterone. To determine if APCCs harbored APA-related mutations, we performed targeted next generation sequencing of DNA from 23 APCCs and adjacent normal adrenal tissue isolated from both formalin-fixed, paraffin-embedded, and frozen tissues. Known aldosterone driver mutations were identified in 8 of 23 (35%) APCCs, including mutations in calcium channel, voltage-dependent, L-type, α1D-subunit (CACNA1D; 6 of 23 APCCs) and ATPase, Na(+)/(K+) transporting, α1-polypeptide (ATP1A1; 2 of 23 APCCs), which were not observed in the adjacent normal adrenal tissue. Overall, we show three major findings: (i) APCCs are common in normal adrenals, (ii) APCCs harbor somatic mutations known to cause excess aldosterone production, and (iii) the mutation spectrum of aldosterone-driving mutations is different in APCCs from that seen in APA. These results provide molecular support for APCC as a precursor of PA.
Optimum Conditions for the Assay of Cardiac RNA: Comparative Content and Effect of Hypertension

Abstract An investigation was made into techniques for the routine measurement of cardiac ribonucleic acid (RNA). Conditions were defined for the determination of rat ventricular RNA, based on uv absorption spectrophotometry. Optimum RNA hydrolysis occurred at 0.3 mol/liter alkali at 37°C for 1 h. Suitable correction factors for non-RNA material were also described and these gave similar results to RNA assayed by colonmetric methods. It was concluded that many of the methods previously reported may cause artifactual observations (in some cases apparent negative amounts of RNA). The technique was applied to the assay of RNA in various regions of the heart (i.e., left and light atrial and the left and right ventricular regions) and compared with noncardiac tissues (i.e., skeletal muscle, liver, bone, intestine, and kidney). The left ventricular RNA concentrations were comparable to the right ventricle and the interventricular septum, but approximately half that of atria. There were very little differences between left and right atrial regions. Differences between atrial and ventricular legions were reduced when data were expressed relative to DNA. The cardiac RNA content was shown to be comparable to skeletal muscle and bone. However, cardiac RNA concentrations were lower than those of kidney, liver, lung, and small intestine. Data were also expressed relative to DNA and showed that cardiac RNA/DNA ratios were higher than those of skeletal muscle and lower than those of bone, kidney, liver, lung, and small intestine. The assay procedure for cardiac RNA was applied to investigations in the hypertrophied left ventricle induced by aortic constriction. After 10 days the RNA concentration (mg/g wet wt) and RNA content (mg/region) increased by 7 and 43%, respectively.
New practitioners and the Pharmacy Practice Model Initiative: our opportunity to define the future.

It is often said that the only constant in life is change. Arguably, many of us would suggest there is another universal constant regarding change: people’s reluctance to accept it. Despite this resistance, we must continually manage change in order to thrive. This is especially true in our own
TMR neural simulation

Abstract A computer program is written to simulate the neural network realizing the discrete-time Markov model of the TMR system. The results obtained, highlighted in this paper, support the theory of the new approach to reliability and fault-tolerance analysis using neural networks.
Occurrence and distribution of novel botryococcene hydrocarbons in freshwater wetlands of the Florida Everglades.

A high abundance of isoprenoid hydrocarbons, the botryococcenes, with carbon numbers from 32 to 34 were detected in the Florida Everglades freshwater wetlands. These compounds were present in varying amounts up to 106 μg/gdw in periphyton, 278 μg/gdw in floc, and 46 μg/gdw in soils. Their structures were determined based on comparison to standards, interpretation of their mass spectra and those of their hydrogenation products, and comparison of Kovats indexes to those reported in the literature. A total of 26 cyclic and acyclic botryococcenes with 8 skeletons were identified, including those with fewer degrees of unsaturation, which are proposed as early diagenetic derivatives from the natural products. This is the first report that botryococcenes occur in the Everglades freshwater wetlands. Their potential biogenetic sources from green algae and cyanobacteria were examined, but neither contained botryococcenes. Thus, the source implication of botryococcenes in this ecosystem needs further study.
Self-consistent-field potential energies for the ground negative-ion and neutral states of HeH, ArH, and ArCl

Self-consistent-field (SCF) calculations have been used to determine the ground negative-ion and ground neutral potential-energy curves for HeH, ArH, and ArCl. In the systems studied, the $X^{1}\ensuremath{\Sigma}$ potential of the negative-ion state is more repulsive at intermediate internuclear separations than the $X^{2}\ensuremath{\Sigma}$ potential of the neutral partners, leading to a curve crossing of the negative-ion state into the continuum. However, at small internuclear separations the negative-ion potential becomes less repulsive than the neutral potential, leading to a second curve crossing out of the continuum. The calculated potential-energy curves are used to provide estimates of the energy thresholds and cross sections for electron detachment in the collisions ${\mathrm{H}}^{\ensuremath{-}}$ + He, ${\mathrm{H}}^{\ensuremath{-}}$ + Ar, and ${\mathrm{Cl}}^{\ensuremath{-}}$ --Ar. The angular thresholds for electron detachment in differential-scattering measurements are also given and compared to experimental data.
Control of calcium hexaluminate grain morphology in in-situ toughened ceramic composites

The influence of processing conditions on the morphology of calcium hexaluminate (CA6) grains in Al2O3: 30 vol% CaO·6Al2O3 (CA6) ceramic composites was investigated. Specimens were prepared by in-situ reaction sintering using precursor powders of alumina, and either calcium carbonate or calcium oxide. In some samples, 1 vol% anorthite glass was added as a sintering aid. X-ray diffraction was used to study the phase development in the as-calcined and sintered states. The resultant microstructures were characterized using both scanning electron microscopy (SEM), and imaging secondary ion mass spectrometry (SIMS). It was found that the CA6 grains developed a platelike morphology when CaCO3 was used as the starting calcium-rich powder. In contrast, samples prepared using CaO resulted in equiaxed CA6 grains. This result was observed to be independent of the anorthite glass addition. The findings are rationalized in terms of distinct CA6 reaction mechanisms, resulting from differences in the reactivity of the powders during the early stages of calcining.
Relationship between C-reactive Protein and Kidney Stone Prevalence

Purpose: We evaluated the relationship between serum C-reactive protein and the lifetime kidney stone prevalence.Materials and Methods: We performed a cross-sectional study of participants from the Continuous National Health and Nutrition Examination Survey (NHANES) from 2007 to 2008 and 2008 to 2009. Data were available on 11,033 participants.Results: On univariate analysis we noted a strong correlation between C-reactive protein quintile and kidney stone history. After adjusting for known confounders multivariate logistic regression revealed a significant relationship between C-reactive protein and the lifetime prevalence of kidney stones in younger individuals (age 20 to 39 years, p for trend = 0.002). In individuals 20 to 39 years old the lifetime prevalence of kidney stones increased with increasing C-reactive protein quintile (p = 0.002 for trend), specifically, those in the third quintile (OR 3.86, 95% CI 1.07–13.88, p = 0.04) and the fifth quintile (OR 3.85, 95% CI 1.46–10.17, p = 0.009). The four...
Basic employability skills: a triangular design approach

Purpose – This paper seeks to examine the basic employability skills needed for job performance, the reception of these skills in college, and the need for additional training in these skills after graduation.Design/methodology/approach – The research was based on a triangular design approach, in which the attitudes of three distinct groups – recent graduates, the faculty who taught them, and human resource managers who recruit them – were studied. The participants responded to a survey that included 47 items measuring eight dimensions of basic employability skills.Findings – The study revealed considerable differences in opinion among the three groups with regard to the skills needed for job performance, the skills received by college graduates, and the additional training needed.Research limitations/implications – The research study was limited to graduates, faculty, and recruiters at a business school in southern California. It is suggested that further studies be conducted to determine whether differe...
Cerebral infarction in Hunter syndrome

Hunter syndrome, or mucopolysaccharidosis type II, is an X-linked recessive disorder resulting from iduronate sulfatase deficiency. Typical manifestations include short stature, mental retardation, hydrocephalus, macroglossia and cardiac valvulopathy. We describe a 21-year-old patient who presented with acute ischemic stroke and evidence of cerebral embolization. The echocardiogram demonstrated thickened mitral and aortic valves as potential sources of emboli. We conclude that ischemic stroke secondary to cardioembolization is a potential complication of Hunter syndrome.
A theoretical investigation into the nucleation of stable crack precursors in polycrystalline ice

The possible formation of small stable cracks (crack precursors) at grain triple points in polycrystalline S2 ice subjected to stresses below that required to nucleate grain-size cracks is examined theoretically at −10° C. The investigation is based on the theory that stress concentrations can arise from the crystal elastic anisotropy and the pile-up of grain boundary dislocations at the triple point. Using an energy approach, numerical simulations of a model show that (i) small stable cracks can initiate from triple points under small stresses, (ii) unstable Griffith cracks can also nucleate, (iii) the smallest nucleation stresses are weakly dependent on hydrostatic compression and crystal orientation, and obey approximately the Hall-Petch relation with respect to the mean grain size, (iv) the crack to grain boundary length ratios are statistically distributed rather than constant, and (v) crack nucleation is strongly influenced by the orientations of the grain boundaries with respect to the applied stress and by the grain boundary dislocation configurations (positive or negative).
suicidal ideation in primary care

OBJECTIVE: To describe the prevalence and clinical characteristics of primary care patients who report suicidal ideation during the month before their medical visit. DESIGN: Analysis of a self-administered suicidal ideation screening item using sociodemographic data, treatment history, and clinical data from structured interviews. SETTING: Three Rhode Island private family practices, a South Carolina family medicine residency, and a California prepaid internal medicine group practice. PATIEJVTS: Adult primary care patients [N=2,749), 18 to 70 years old, who are able to read and write English, able to complete study forms, and willing to provide informed consent. RESULTS: Sixty-seven (2.44%) of the patients reported suicidal ideation (“feeling suicidal”) during the past month, and most of these patients (58.2%) received no mental health care during that time. The adjusted risk of suicidal ideation was significantly elevated for patients with self-reported fair or poor physical health (odds ratio [OR] 2.5; 95% confidence interval [CI1 1.5, 4.1), fair to poor emotional health (OR 18.0; 95% CI 8.8, 37.0), marital distress (OR 4.4; 95% CI 2.2, 8.8), and recent mental health-related work loss (OR 6.3; 95% CI 3.7, 10.5). In the California sample, patients with major depression (OR 31.2; 95% CI 12.8, 76.1), generalized anxiety disorder (OR 23.4; 95% CI 8.1, 67.1), and drug abuse or dependence (OR 9.6; 95% CI 2.9, 31.6) were at increased risk of suicidal ideation. The “feeling suicidal” item identified 10 of 12 patients who acknowledged a recent plan to kill themselves. CONCLUSIONS: In these primary care patients, suicidal ideation is strongly associated with mental disorder and mental health-related functional impairment, and can be detected with a single self-report “feeling suicidal” item.
Arch filaments associated with the formation of sunspots by umbral merging

The formation of a sunspot during the emergence of a new group is described. The spot forms from a cluster of small umbrae that do not converge. Rather, the individual umbrae enlarge and merge into a spot covering the same area. The formation of each umbra is accompanied by an intensification of the arch filament anchored in it. The formation of the sunspot produces no apparent change in the total field.
SIMPLIFIED MODELS FOR TURBULENT DIFFUSION : THEORY, NUMERICAL MODELLING, AND PHYSICAL PHENOMENA

Abstract Several simple mathematical models for the turbulent diffusion of a passive scalar field are developed here with an emphasis on the symbiotic interaction between rigorous mathematical theory (including exact solutions), physical intuition, and numerical simulations. The homogenization theory for periodic velocity fields and random velocity fields with short-range correlations is presented and utilized to examine subtle ways in which the flow geometry can influence the large-scale effective scalar diffusivity. Various forms of anomalous diffusion are then illustrated in some exactly solvable random velocity field models with long-range correlations similar to those present in fully developed turbulence. Here both random shear layer models with special geometry but general correlation structure as well as isotropic rapidly decorrelating models are emphasized. Some of the issues studied in detail in these models are superdiffusive and subdiffusive transport, pair dispersion, fractal dimensions of scalar interfaces, spectral scaling regimes, small-scale and large-scale scalar intermittency, and qualitative behavior over finite time intervals. Finally, it is demonstrated how exactly solvable models can be applied to test and design numerical simulation strategies and theoretical closure approximations for turbulent diffusion.
Monitoring people treated with isotretinoin for depression

Depression has been reported in some patients treated with isotretinoin, an effective medication for nodulocystic acne, a serious disorder resulting in permanent scarring. Since major depression, a common disorder associated with multiple health risks including suicide attempts and treatment noncompliance, may occur during the course of treatment with isotretinoin, persons treated with isotretinoin must be screened for depression before starting treatment and monitored for depression regularly during the course of treatment with isotretinoin. Those with evidence of depression must then be referred for prompt treatment to abort serious adverse outcomes, including suicide. Psychologists constitute key members of the treatment team of patients taking isotretinoin.
Analysis of three factors possibly influencing the outcome of a science review process.

We analyzed a process for the annual selection of a Federal agency's best peer-reviewed, scientific papers with the goal to develop a relatively simple method that would use publicly available data to assess the presence of factors, other than scientific excellence and merit, in an award-making process that is to recognize scientific excellence and merit. Our specific goals were (a) to determine if journal, disease category, or major paper topics affected the scientific-review outcome by (b) developing design and analytic approaches to detect potential bias in the scientific review process. While indeed journal, disease category, and major paper topics were unrelated to winning, our methodology was sensitive enough to detect differences between the ranks of journals for winners and non-winners.
Procedures for the study of the flexible-disk to head interface

The response of a rotating flexible disk interacting with a read-write head is analyzed. The disk deflection due to an arbitrary distributed normal pressure is coupled with the Reynolds lubrication equation for the disk-to-head air bearing. Procedures which considerably reduce the computation time necessary for obtaining a converged solution are described. A parameter study is then discussed and its results presented.
Magnetostratigraphy and tephrochronology of an upper Pliocene to Holocene record in lake sediments at Tulelake, northern California

Combined paleomagnetic and tephra chronologies of one of the most complete middle Pliocene through Holocene stratigraphic records yet recovered in western North America provide a reference section for much of northwestern North America and adjacent Pacific Ocean. Five long drill cores of lacustrine sediments at Tulelake, northern California, recovered a nearly continuous 331-m-thick record spanning the past 3 m.y. The Brunhes Normal-Polarity, Matuyama Reversed-Polarity, and Gauss Normal-Polarity Chronozones are recognized; within these, the Jaramillo, Olduvai, Reunion(?), and Kaena(?) Subchronozones are present. Six short stratigraphic intervals exhibit anomalous remanent inclinations that may record excursions and brief subchrons within the Brunhes and Matuyama Chronozones. Age estimates suggest correlation of five of the anomalous intervals with (1) one of the Biwa excursions at about 18,000 yr B.P., (2) the Mono Lake excursion at about 27,000 yr B.P., (3) the Blake Reversed-Polarity Subchron at about 114,000 yr B.P., (4) the Kamikatsura Normal-Polarity Subchron at about 850,000 yr B.P., and (5) the Cobb Mountain Normal-Polarity Subchron at about 1.10 Ma. Age of the sixth interval of anomalous inclination is broadly constrained between 117,000 and 180,000 yr B.P. Sixty-three individual tephra layers were characterized by electron-microprobe and X-ray fluorescence analyses of volcanic glass shards. Identified tephra of relatively well known age include (1) the basal airfall pumice at Llao Rock, 7015 yr B.P.; (2) the Trego Hot Springs Bed, 23,400 yr B.P.; (3) the Olema ash bed, between 55,000 and 75,000 yr B.P.; (4) the airfall pumice at Cloudcap Road ("Pumice Castle-like tephra 2"), about 120,000 yr B.P.; (5) the Rockland ash bed, about 410,000 yr B.P.; (6) the Lava Creek-B ash bed, 620,000 yr B.P.; (7) the Rio Dell ash bed, about 1.45 Ma; and (8) the Bear Gulch ash bed, about 1.9 Ma. A sedimentation-rate curve based on independently dated tephra and polarity reversals is used to infer age estimates of undated or previously unidentified ash beds. Some of these ash beds are found over large areas of the western United States and eastern Pacific Ocean basin and provide widespread horizons for correlation. Most of the tephra at Tulelake records eruptions from the nearby southern and central Cascade Range of Oregon and northern California, and the Medicine Lake Highland of northern California. Deposition took place during most of the past 3 m.y. within the Tulelake basin; notable periods of slow or sporadic accumulation, or erosion, occurred between about 620,000 and 200,000 yr B.P. and between about 2.5 and 2.1 Ma. Rapid deposition occurred during marine oxygen-isotope stage 6, between about 170 and 125 ka. Regional volcanism during the past 3 m.y. was markedly episodic, with notable volcanic activity from about 2.1 to 1.9 Ma and from 0.4 Ma to the present.
High-bandwidth velocity-matched optical directional coupler modulator in AlGaAs/GaAs

We report a design of a very high frequency A1GaAs/GaAs optical modulator using a dielectric loading velocity matching technique. The optical modulator is a directional coupler which is covered with a thin coating of Ta2O5 to match the velocities of the lightwave and the if modulating signal to within 2%. The optical and rf characteristics of the modulator are analyzed using the effective index and finite difference methods. The small signal 3 dB bandwidth for the modulator is predicted to exceed 45GHz and 100 GHz for biasing at the null point and in the linear region respectively, with a maximum modulation voltage of 5V at 830nm wavelength.
Training as regulation and development: An exploration of the needs of enterprise systems users

The view of the organization as a system that 'processes' information or 'solves' problems is at odds with the dynamics of change associated with the development and use of IS in an organization. A significant consequence of this mismatch is in training that does not meet the needs of either the user or management communities, giving rise to sub optimal organization performance and inertia. We explored such issues by examining recent research into organizational development and training. The particular challenges presented in the development and implementation of large-scale enterprise systems were explored to reveal a discontinuity in the constructs underpinning a development. A theoretic model that bridged some of the gaps between the bodies of research was developed and a brief empirical study provided a proof of concept for the model. The paper concludes with a discussion of the model's implications for theory and practice.
The Weibull Stress Model for Predicting Cleavage Fracture in the Ductile-to-Brittle Transition Region

Transgranular cleavage fracture in the ductile-to-brittle transition region of ferritic steels often leads to spectacular and catastrophic failures of engineering structures. Due to the strongly stochastic effects of metallurgical scale inhomogenieties together with the nonlinear mechanical response from plastic deformation, the measured fracture toughness data exhibit a large degree of scatter and a strong dependence on constraint. This has stimulated an increasing amount of research over the past two decades, among which the Weibull stress model originally proposed by the Beremin group has gained much popularity. This model is based on weakest link statistics and provides a framework to quantify the relationship between macro and microscale driving forces for cleavage fracture. It has been successfully applied to predict constraint effects on cleavage fracture and on the scatter of macroscopic fracture toughness values. This paper provides a brief review of the research conducted by the authors in recent years to extend the engineering applicability of the Weibull stress model to predict cleavage fracture in ferritic steels. These recent efforts have introduced a threshold value in the Weibull stress model, introduced more robust calibration methods for determination of model parameters, predicted experimentally observed constraint effects, demonstrated temperature and loading rate effects on the model parameters, and expanded the original Beremin model to include the effects of microcrack nucleation.Copyright © 2008 by ASME
Epigenetic Mechanisms of Memory Formation and Reconsolidation

Memory consolidation involves transcriptional control of genes in neurons to stabilize a newly formed memory. Following retrieval, a once consolidated memory destabilizes and again requires gene transcription changes in order to restabilize, a process referred to as reconsolidation. Understanding the molecular mechanisms of gene transcription during the consolidation and reconsolidation processes could provide crucial insights into normal memory formation and memory dysfunction associated with psychiatric disorders. In the past decade, modifications of epigenetic markers such as DNA methylation and posttranslational modifications of histone proteins have emerged as critical transcriptional regulators of gene expression during initial memory formation and after retrieval. In light of the rapidly growing literature in this exciting area of research, we here examine the most recent and latest evidence demonstrating how memory acquisition and retrieval trigger epigenetic changes during the consolidation and reconsolidation phases to impact behavior. In particular we focus on the reconsolidation process, where we discuss the already identified epigenetic regulators of gene transcription during memory reconsolidation, while exploring other potential epigenetic modifications that may also be involved, and expand on how these epigenetic modifications may be precisely and temporally controlled by important signaling cascades critical to the reconsolidation process. Finally, we explore the possibility that epigenetic mechanisms may serve to regulate a system or circuit level reconsolidation process and may be involved in retrieval-dependent memory updating. Hence, we propose that epigenetic mechanisms coordinate changes in neuronal gene transcription, not only during the initial memory consolidation phase, but are triggered by retrieval to regulate molecular and cellular processes during memory reconsolidation.
Light stop from b–τ Yukawa unification

Abstract We show that b – τ Yukawa unification can be successfully implemented in the constrained minimal supersymmetric model and it yields the stop co-annihilation scenario. The lightest supersymmetric particle is a bino-like dark matter neutralino, which is accompanied by a 10–20% heavier stop of mass ∼ 100 – 330 GeV . We highlight some benchmark points which show a gluino with mass ∼ 0.6 – 1.7 TeV , while the first two family squarks and all sleptons have masses in the multi-TeV range.
New results on single-photon upconversion

The process of up-conversion is shown to enable superior single-photon detectors in the infrared, compared to InGaAs and germanium Avalanche Photodiodes (APDs) (normally used for IR single photon detection). After up-converting an infrared photon to a visible one in a non-linear crystal-Periodically Poled Lithium Niobate (PPLN)-we use a silicon APD to efficiently detect the frequency up-shifted IR photon. We have demonstrated this process at the "high-intensity" level and at the single-photon level, where the up-converted state is effectively a superposition of the single photon Fock state and the vacuum state. We achieve an 80% conversion efficiency over the width of the pulse, and show that this process is coherent, a necessary ingredient for many applications.
A comparison of chronic pain behavior following local application of tumor necrosis factor α to the normal and mechanically compressed lumbar ganglia in the rat

To study the role of inflammatory cytokines in the initiation and persistence of radiculopathy as seen in humans, tumor necrosis factor alpha (TNF-alpha) was administered either to normal, uninjured L5 dorsal root ganglia (DRG) of rats via a hole drilled through the transverse process, or to chronically compressed L5 DRG via a hollow stainless steel rod inserted into the intervertebral foramen. In other experiments, a mixture of soluble TNF receptors (sTNF-Rs: sTNF-RIplus minussTNF-RII) was locally delivered to the chronically or acutely compressed DRG to neutralize the activity of endogenous TNF-alpha. Behavioral tests of mechanical allodynia were performed before and after TNF-alpha administration. Infusion of the normal DRG with TNF-alpha at a rate of 1 microl/h for 7 days induced ipsilateral mechanical allodynia (i.e. decreased mechanical withdrawal threshold) that lasted about 2 weeks. Infusion of the compressed DRG did not alter compression-induced allodynia within the first operative week but substantially enhanced the ipsilateral allodynia after the first postoperative week. Neutralizing the activity of endogenous TNF-alpha of the compressed DRG with sTNF-Rs reduced allodynia for 3 days, but was subsequently without effect. Similar results were obtained when sTNF-Rs were chronically administrated at the acutely compressed ganglion. Results demonstrated that exogenous TNF-alpha causes pain and mechanical allodynia when deposited at the normal DRG, and further enhances the ongoing allodynia when administrated at the compressed DRG. Results also suggest that endogenous TNF-alpha contributes to the early development of mechanical allodynia in rats with chronic DRG compression.
Numerical calculation of fluid flow in a continuous casting tundish

The deposition of deoxidation and reoxidation products in continuous casting tundish nozzles results in poor surface quality of the cast product and in extreme cases, disruption of the operating schedule. Since the flow of steel in the tundish is central to the behavior of nonmetallic inclusions in the tundish, the details of the flow field are determined numerically by appropriate solutions of the equations of change. The effects of the changes of the internal configuration of the tundish and various casting parameters on the computed velocity fields, particle trajectories, and particle residence times are investigated. The conclusions drawn from the computed results are compared with the results of various independent water model studies.
Two bounds on the maximum phonon-mediated superconducting transition temperature

Two simple bounds on the ${T}_{c}$ of conventional, phonon-mediated superconductors are derived within the framework of Eliashberg theory in the strong-coupling regime. The first bound is set by the total electron-phonon coupling available within a material given the hypothetical ability to arbitrarily dope the material. This bound is studied by deriving a generalization of the McMillan-Hopfield parameter $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\eta}}(E)$, which measures the strength of electron-phonon coupling including anisotropy effects and rigid-band doping of the Fermi level to $E$. The second bound is set by the softening of phonons to instability due to strong electron-phonon coupling with electrons at the Fermi level. We apply these bounds to some covalent superconductors including ${\mathrm{MgB}}_{2}$, where ${T}_{c}$ reaches the first bound, and boron-doped diamond, which is far from its bounds.
FDI Variations in Emerging Markets: The Role of Credible Commitments—With Special Reference to Asia

What accounts for variations in foreign direct investments (FDI) in emerging telecommunications markets? This article shows that the key to capturing FDI flows is making and enforcing credible commitments both internationally and domestically toward liberalization reform in telecommunications sectors: the differences in such commitments account for FDI variations. The commitments made by emerging markets in the World Trade Organization's (WTO) telecommunications accord are first examined. Furthermore, a qualitative analysis of four important Asian markets seeks to correlate such commitments with FDI flows. The case of China is conceptually and empirically interesting: the country's size, growth rate, and state-led coordination mechanisms create a credible commitment illusion, at least in the short run.
Theory of optical orientation in n -type semiconductors

Time-resolved measurements of magnetization in $n\text{\ensuremath{-}}\mathrm{GaAs}$ have revealed a rich array of spin decoherence processes, and have shown that fairly long lifetimes $(\ensuremath{\sim}100\phantom{\rule{0.3em}{0ex}}\mathrm{ns})$ can be achieved under certain circumstances. In time-resolved Faraday rotation and time-resolved Kerr rotation the evolution of the magnetization can be followed as a function of temperature, applied field, doping level, and excitation level. We present a theory for the spin relaxation in $n\text{\ensuremath{-}}\mathrm{GaAs}$ based on a set of rate equations for two interacting thermalized subsystems of spins: localized states on donor sites and itinerant states in the conduction band. The conduction-band spins relax by scattering from defects or phonons through the D'yakonov-Perel' mechanism, while the localized spins relax by interacting with phonons (when in an applied field) or through the Dzyaloshinskii-Moriya interaction. In this model, numerous features of the data, including puzzling temperature and doping dependencies of the relaxation time, find an explanation.
Coulombic Dragging of Molecules on Surfaces Induced by Separately Flowing Liquids

We demonstrate that ions or polar molecules can be driven by fluctuating Coulombic forces induced by flowing polar liquids at nanometer separations. We simulate this intriguing phenomenon on small ions and polar molecules driven on the surfaces of carbon nanotubes through which a flow of water is passing. Our simulations show that the average velocities of the driven molecules are close to those of the passing liquid. These transport phenomena open the door for many potential applications.
MRIVIEW: An interactive computational tool for investigation of brain structure and function

MRIVIEW is a software system that uses image processing and visualization to provide neuroscience researchers with an integrated environment for combining functional and anatomical information. Key features of the software include semi-automated segmentation of volumetric head data and an interactive coordinate reconciliation method which utilizes surface visualization. The current system is a precursor to a computational brain atlas. We describe features this atlas will incorporate, including methods under development for visualizing brain functional data obtained from several different research modalities. >