cssi/SciSciGPT-SciSciNet huggingface dataset:
SOMITE STRIPS : AN EMBRYO FILLET PREPARATION

Publisher Summary This chapter discusses somite strips—an embryo fillet preparation. Somite strips can be used to study somitic guidance cues at the cellular and molecular levels. This assay confers the benefits of studying a semi-intact system in a culture setting. It is a hybrid in vivo–in vitro assay that exposes anterior and posterior sclerotomes to view and yet retains in culture both the segmental architecture and typical molecular characteristics, such as differential binding to peanut agglutinin lectin. Anatomical studies have shown that differences between anterior and posterior somites guide axons and neural crest cells, both of which traverse anterior but not posterior somites to form segmental arrays corresponding to the segmentally repeated somites. The somitic tissue responsible for the permissive and inhibitory subdivisions is the sclerotome; the dermatome and the myotome are not essential for segmental outgrowth patterns. However, although it is known which tissues carry the guidance cues, the molecules or the cellular interactions that mediate the responses to these tissues have yet to be identified.
Signal Detection Theory

In perceptual, cognitive, and diagnostic tasks, accuracy depends on both limited sensitivity and the application of a decision process. By making explicit assumptions about the nature of the cognitive representation, signal detection theory (SDT) measures the contributions of these two components of performance. (Other approaches to assessing accuracy also constrain possible representations, although not all are explicit about their assumptions.) The receiver-operating characteristic (ROC) curve, which takes account of response bias in decision-making by examining conditions in which this bias varies, is a valuable tool for sensitivity measurement: The ROC curve provides an assumption-free index of accuracy, and is also used to distinguish among competing representations. The simplest form of SDT assumes that different stimulus possibilities lead to distributions of strength on a decision axis, and this model can be applied to many experimental paradigms in which a single stimulus is presented on each trial. Using more complex representations in which distributions lie in a multidimensional space, SDT predicts the relation between different paradigms for measuring accuracy (e.g., two-alternative forced-choice, same-different). Multidimensional representations also describe the classification and identification of stimuli from complex stimulus sets, and are particularly useful in analyses of perceptual interaction and attention. Keywords: discrimination; perceptual independence; receiver operating characteristic (ROC); response bias; sensitivity; thresholds
Zeros of discretized continuous systems expressed in the Euler operator-an asymptotic analysis

The structure of the zeros of SISO continuous time systems which are discretized via a zero order hold and expressed in the Euler operator, /spl epsiv/ (/spl epsiv/=(x-1)/T), is studied. It is shown that when state space descriptions of linear SISO continuous time systems with relative degree /spl ges/2 are discretized, the zero dynamics of the resulting discrete system is singularly perturbed and shows a reparation of time scale; the fast time scale corresponding to the zeros introduced by the sampling process. Finally, implications of the result to control design based on pole zero cancellation is discussed.
Aminoacylation of Escherichia coli valine transfer ribonucleic acid by Neurospora crassa phenylalanyl transfer ribonucleic acid synthetase in tris(hydroxymethyl)aminomethane hydrochloric acid and potassium cacodylate buffers. Effect of salts, dimethyl sulfoxide, ethanol, and 2-mercaptoethanol.

Abstract Aminoacylation of valine transfer RNA from Escherichia coli by phenylalanyl-tRNA synthetase from Neurospora crassa is extremely sensitive to assay conditions. In Tris buffer under optimal conditions, the final yield of phenylalanyl-tRNAval is a function of enzyme concentration, and aminoacylation is incomplete even at very high enzyme concentrations. At low enzyme concentrations, the final yield of phenylalanyl-tRNAval is increased 10-fold by 20% dimethyl sulfoxide. Ethanol (10%) also increases the extent of aminoacylation, whereas NaCl, NH4Cl, and 2-mercaptoethanol all lead to decreased final yields. When cacodylate buffer is used in place of Tris buffer, the pH optimum for aminoacylation is shifted from above 8.1 to 6.3, and various kinetic properties of the aminoacylation reaction are changed. At low enzyme concentrations over 10 times more phenylalanyl-tRNAval is formed in cacodylate buffer than is formed in Tris buffer. Dimethyl sulfoxide (20%) and all concentrations of 2-mercaptoethanol, ethanol, NaCl, and NH4Cl inhibit aminoacylation in cacodylate buffer. These results emphasize that buffers are not necessarily inert compounds merely maintaining the pH of a reaction mixture and that the first step in the study of a heterologous aminoacylation reaction should be the careful optimization of reaction conditions.
Na+/K+-ATPase regulation in Dahl salt-sensitive and salt-resistant rats.

Abstract Circulating Na+/K+-ATPase inhibitors have been implicated in volume-expanded forms of hypertension. Inhibition of vascular smooth muscle cell Na+/K+-ATPase has been demonstrated to elevate intracellular Ca2+ levels and enhance contractility, thus providing a mechanism of raised peripheral resistance. In cells chronically subjected to Na+/K+-ATPase inhibition, however, new Na+/K+-ATPase molecules are synthesized, which then restore the intracellular milieu to preinsult conditions. Restoral of the preinsult intracellular milieu in vascular smooth muscle cells would then be expected to lead to the reduction of muscle cell contractility and peripheral resistance. Thus circulating Na+/K+-ATPase inhibitors may not be effective in eliciting chronic forms of hypertension unless the target cell "homeostatic response" is impaired. We demonstrate an apparent such impairment in Dahl salt-sensitive rats, a genetic model of salt-sensitive hypertension.
MaizeGDB: The Maize Genetics and Genomics Database

MaizeGDB is the community database for biological information about the crop plant Zea mays. Genomic, genetic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website ( http://www.maizegdb.org ) are custom interfaces enabling researchers to browse data and to seek out specific information matching explicit search criteria. In addition, pre-compiled reports are made available for particular types of data and bulletin boards are provided to facilitate communication and coordination among members of the community of maize geneticists.
Electron cyclotron resonance microwave plasma neutralizer for ion thruster systems

Summary form only given. We report the application of the Getty, large area, ECR-plasma source, as an electron source for the neutralization of ion thruster beams. This plasma source consists of a large waveguide horn in which the microwave output end is covered with cross-polarized rows of permanent magnets separated by slots. The large-area plasma is formed in the electron-cyclotron-resonant magnetic fields outside the magnet-bar slots. Typical microwave parameters are: frequency of 2.45 GHz, and power levels of hundreds of W. Electron densities have been measured to be overdense, at values up to 6 E11/cc at this frequency. Scaling studies are underway to raise the frequency to 6 GHz for a potential 6-fold increase in the electron density.
Quantitative Rationalization of Gemfibrozil Drug Interactions: Consideration of Transporters-Enzyme Interplay and the Role of Circulating Metabolite Gemfibrozil 1-O-β-Glucuronide

Gemfibrozil has been suggested as a sensitive cytochrome P450 2C8 (CYP2C8) inhibitor for clinical investigation by the U.S. Food and Drug Administration and the European Medicines Agency. However, gemfibrozil drug-drug interactions (DDIs) are complex; its major circulating metabolite, gemfibrozil 1-O-β-glucuronide (Gem-Glu), exhibits time-dependent inhibition of CYP2C8, and both parent and metabolite also behave as moderate inhibitors of organic anion transporting polypeptide 1B1 (OATP1B1) in vitro. Additionally, parent and metabolite also inhibit renal transport mediated by OAT3. Here, in vitro inhibition data for gemfibrozil and Gem-Glu were used to assess their impact on the pharmacokinetics of several victim drugs (including rosiglitazone, pioglitazone, cerivastatin, and repaglinide) by employing both static mechanistic and dynamic physiologically based pharmacokinetic (PBPK) models. Of the 48 cases evaluated using the static models, about 75% and 98% of the DDIs were predicted within 1.5- and 2-fold of the observed values, respectively, when incorporating the interaction potential of both gemfibrozil and its 1-O-β-glucuronide. Moreover, the PBPK model was able to recover the plasma profiles of rosiglitazone, pioglitazone, cerivastatin, and repaglinide under control and gemfibrozil treatment conditions. Analyses suggest that Gem-Glu is the major contributor to the DDIs, and its exposure needed to bring about complete inactivation of CYP2C8 is only a fraction of that achieved in the clinic after a therapeutic gemfibrozil dose. Overall, the complex interactions of gemfibrozil can be quantitatively rationalized, and the learnings from this analysis can be applied in support of future predictions of gemfibrozil DDIs.
Navigation Solution to Maneuver a Spacecraft Relative to a Sphere Centered on a Cooperative Satellite

Abstract A differential correction algorithm is presented to deliver an impulsive maneuver to a satellite to place it within a sphere, with a user defined radius, centered around a non-maneuvering satellite within a constrained time. The differential correction algorithm develops and utilizes the State Transition Matrix along with the Equations of Motion and multiple satellite׳s state information to determine the optimum trajectory to achieve the desired results. The results from the differential correction algorithm are very accurate for prograde orbits, as presented. The results allow for orbit design trade-offs, including satellites׳ initial inclinations, semi-major axes, as well as the ballistic coefficients. The results also provide an empirical method to determine the optimum Δ V solution for the provided problem. Understanding that the minimum fuel solution lies with a semi-major axis ratio of 1, a very accurate empirical approximation is presented for semi-major axis ratio values less than and greater than 1. This work ultimately provides the generalized framework for applying the algorithm to a unique user defined maneuvering spacecraft scenario.
Perceptions of Appropriate Services for Juvenile Offenders

This study provides a descriptive view of juvenile justice gatekeepers' perceptions of appropriate services for juvenile offenders. These personnel do not appear to have a high regard for alternative services without a therapeutic orientation. As these gatekeepers are lynchpins of both the referral process and the establishment of alternative services in juvenile justice, this predilection is important to note as a factor that may motivate accommodations by these personnel to changes in juvenile justice policy. Professionals in this system seem most likely to believe in therapeutic treatment for juvenile offenders, and this fact could go further than the intents of any policy mandates toward determining the actual practice of juvenile justice.
Ontogeny of the umbilical cord and placenta in the Atlantic sharpnose shark, Rhizoprionodon terraenovae

The Atlantic sharpnose shark is a viviparous anamniote that develops an epitheliochorial yolksac placenta. Initially, contents of the yolksac nourish the embryos. Yolk is partially digested in the yolk syncytial-endoderm complex and subsequently transferred to the vitelline circulation. Yolk is also transported by ciliary activity of the yolk stalk ductus to the fetal gut for digestion. When embryos are 4.0cm in length, vascular ridges, termed appendiculae, develop on the yolk stalk. As yolk stores are depleted, the yolksac differentiates into the fetal portion of the placenta and the uterus abutting the yolksac differentiates into the maternal portion of the placenta. The yolk stalk differentiates into an elongate umbilical cord. The uterine epithelium produces secretions that are positive by the periodic acid-Schiff and alcian blue methods and metachromatic when stained with toluidine blue. Uterine capillaries are continuous and the surface epithelium is active both in secretion and transport of nutrients. When the embryos are 7–10cm in length, appendiculae are elongate, branched and populated by separate microvillar and granulated cells. Appendiculae may function as a paraplacental nutrient absorptive organ and be involved in the regulation of osmolarity of periembryonic fluids. The fetal placenta has two functional regions: a proximal portion that is presumed to function as a steroid producing organ and a distal portion that effects nutrient and metabolic exchange between the mother and fetus. Characteristics of the fetal placenta include endocytotic activity, crystalline-like cytoplasmic bodies and fenestrated capillaries. Fetal and maternal components of the placenta are separated by the egg envelope.
Three Environmental Probabilistic Risk Problems

Risk analysis may be defined as the problem of estimating the probabilities of rare events and the magnitudes of associated damages. The topic unifies the environmental sciences. This paper considers risk analyses for earthquakes, wildfires and floods. The computation of insurance premiums is used to motivate and unite the work.
Differential induction of IgE-mediated anaphylaxis after soluble vs. cell-bound tolerogenic peptide therapy of autoimmune encephalomyelitis.

The ability of different forms of myelin peptides to induce tolerance for the treatment of preestablished murine experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis, was evaluated. i.v. administration of myelin peptide-pulsed, ethylene carbodiimide-fixed syngeneic splenocytes, but not soluble myelin peptide monomers or oligomers, proved exceedingly effective at treating preestablished EAE, resulting in amelioration of disease progression. In addition to the lack of therapeutic efficacy of soluble peptide and peptide oligomer, administering them i.v. after the onset of clinical symptoms in many but not all peptide-induced EAE models led to a rapid-onset anaphylactic reaction characterized by respiratory distress, erythema, decreased body temperature, unresponsiveness, and, often, death. By using anti-IgE antibody treatments and mice with targeted mutations of the FcγRIII α-chain or the common γ-chain of FceRI and FcγRI/III, we demonstrate that IgE crosslinking of FceRI appears to be necessary and sufficient for myelin peptide-induced anaphylaxis. The implications of these findings to myelin peptide/protein tolerance strategies for the treatment of multiple sclerosis are discussed.
Long work hours, hypertension, and cardiovascular disease

Several studies of myocardial infarction and two studies of blood pressure have shown associations with long work hours (greater than 55-60 hours per week). However, the number of studies of long work hours with cardiovascular outcomes is limited, and further research is needed to better understand the mechanisms and moderating factors.
Single mating and its implications for kinship structure in a multiple-queen wasp, Parachartergus colobopterus

The number of matings by social insect queens is an important determinant of the kinship structure of their colonies, and it is therefore expected to affect a variety of kin-selected worker strategies. Here we report mate number data for Parachartergus colobopterus, the first such data for any member of the polygynous epiponine wasps. Mate number is assessed by microsatellite genotyping of the sperm stored in queen spermathecae. Queens of this species mate only once. This finding is consistent with a prediction of several theories positing that multiple mating functions to increase genetic diversity and is therefore less necessary in multiple-queen species. The finding of single mating, together with earlier data, allows estimation of effective queen numbers for all colonies, 4.40 queens, for male-producing colonies, 4.16 queens, and for queen-producing colonies, 1.18.
A Novel Atoh1 “Self-Terminating” Mouse Model Reveals the Necessity of Proper Atoh1 Level and Duration for Hair Cell Differentiation and Viability

Atonal homolog1 (Atoh1) is a bHLH transcription factor essential for inner ear hair cell differentiation. Targeted expression of Atoh1 at various stages in development can result in hair cell differentiation in the ear. However, the level and duration of Atoh1 expression required for proper hair cell differentiation and maintenance remain unknown. We generated an Atoh1 conditional knockout (CKO) mouse line using Tg(Atoh1-cre), in which the cre expression is driven by an Atoh1 enhancer element that is regulated by Atoh1 protein to "self-terminate" its expression. The mutant mice show transient, limited expression of Atoh1 in all hair cells in the ear. In the organ of Corti, reduction and delayed deletion of Atoh1 result in progressive loss of almost all the inner hair cells and the majority of the outer hair cells within three weeks after birth. The remaining cells express hair cell marker Myo7a and attract nerve fibers, but do not differentiate normal stereocilia bundles. Some Myo7a-positive cells persist in the cochlea into adult stages in the position of outer hair cells, flanked by a single row of pillar cells and two to three rows of disorganized Deiters cells. Gene expression analyses of Atoh1, Barhl1 and Pou4f3, genes required for survival and maturation of hair cells, reveal earlier and higher expression levels in the inner compared to the outer hair cells. Our data show that Atoh1 is crucial for hair cell mechanotransduction development, viability, and maintenance and also suggest that Atoh1 expression level and duration may play a role in inner vs. outer hair cell development. These genetically engineered Atoh1 CKO mice provide a novel model for establishing critical conditions needed to regenerate viable and functional hair cells with Atoh1 therapy.
Chain transfer of vegetable oil macromonomers in acrylic solution copolymerization

The use of vegetable oil macromonomers (VOMMs) as comonomers in emulsion polymerization enables good film coalescence without the use of solvents that constitute volatile organic compounds (VOCs). VOMMs are derived from renewable resources and offer the potential of post-application crosslinking via auto-oxidation. However, chain transfer reactions of VOMMs with initiator and/or polymer radicals during emulsion polymerization reduce the amount of allylic hydrogen atoms available for primary auto-oxidation during drying. Vegetable oils and derivatives were reacted with butyl acrylate and methyl methacrylate via solution polymerization, and the polymerization was monitored using in situ infrared spectroscopy to determine the extent of chain transfer. 1H NMR spectroscopy was used to determine the loci of chain transfer and the molecular weight characteristics of the polymers were characterized by SEC. Solution polymerization was utilized because this limited temperature fluctuations and insolubility of the polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A Longitudinal Comparison of the Academic, Affective, and Personal Characteristics of Persisters and Nonpersisters in Teacher Preparation

Abstract This study was designed to ascertain whether differences exist among the academic, affective, and personal characteristics of teacher-education persisters and nonpersisters. The subjects comprised a longitudinal sample of about 550 teacher candidates entering teacher preparation at one institution. After 5 years from the commencement of their training, 357 (65%) of these individuals had persisted through their teacher training, and attrition from teacher training increased the quality of the remaining pool of teacher candidates. Teacher training persisters earned higher university grade point averages, developed higher levels of basic academic skills, expressed fewer concerns about the task of teaching, and reported a more positive attitude toward teaching as a career than did nonpersisters.
MR imaging of tendon abnormalities of the elbow

Tendon injuries about the elbow are among the most commonly encountered pathology in this articulation. These injuries are often the result of chronic repetitive microtrauma but can be seen in the setting of acute trauma. This article focuses on the imaging diagnosis of tendon pathology in the elbow and the associated findings that can be seen with tendon injury. A detailed understanding of common pathology and patterns of injury can facilitate the ease and accuracy of imaging diagnosis.
Strain and fabric analyses based on porphyroclast interaction

Abstract Two-dimensional computer models of the interaction of elliptical clasts in a variety of kinematic conditions are used to study how clast imbrication and shape fabric development relate to strain and strain history. The models provide templates, for a known clast density and clast ellipticity, that correlate clast imbrication, angle of collision and clast shape fabric to strain and kinematics of deformed rocks. Modeling also shows that the mode of clast interaction plays a significant role in the accumulation of imbricated clasts and the development of shape fabric. Upon collision between clasts, the trains formed can remain fixed or rotate. If they rotate, imbricated clasts can become independent when they are no longer forced together by the flow. Based upon the mode of clast and train rotation (using the March rotation of passive lines and the Jeffery rotation of rigid particles as end-members), three models are defined in an attempt to simulate the conditions of clast interaction under varying conditions. The March-fixed train, March-rotating train and Jeffery-rotating train models simulate solid-state, intermediate and magmatic conditions, respectively. Modeling shows that the two March models produce similar results, but the Jeffery model of train rotation always produces a lower proportion of imbricated clasts and a much weaker shape fabric. Application of the modeling to the study of a syntectonic granite in the Sierra Nevada suggests that deformation was dominated by simple shear. Some K-feldspar imbrication and fabric development took place initially in the magmatic stage, and culminated in the solid state to produce a large proportion of imbricated K-feldspar porphyroclasts which define a strong shape fabric. This type of analysis provides a rationale to determine syn-vs post-emplacement deformation in the granite.
Type 1 Diabetes Mellitus

1. Francine Ratner Kaufman, MD* 1. *Professor of Pediatrics, The Keck School of Medicine of University of Southern California; Head, Center for Diabetes, Endocrinology and Metabolism, Children’s Hospital of Los Angeles, Los Angeles, CA After completing this article, readers should be able to: 1. Describe the pathogenesis of type 1 diabetes. 2. Review intensive diabetes management protocols, new insulin preparations, and insulin delivery systems. 3. Describe the importance of home glucose and ketone monitoring and the new monitoring methodologies. 4. Elucidate the key elements of the outpatient diabetes examination and screening for diabetes complications. 5. Characterize the importance of the multidisciplinary team in the management and education of children who have type 1 diabetes and their families. Many advances have been made since the Diabetes Control and Complications Trial (DCCT) provided irrefutable evidence of the benefits of following a system of diabetes management that allows for optimal glycemia for patients who have type 1 diabetes. These advances include an ever-increasing armamentarium of types of insulin that have varying onsets and durations of action, insulin delivery systems, improved methods for monitoring glycemia at home, and potential agents that could be used for diabetes prevention or to preserve residual beta-cell function at the time of diagnosis. These exciting advances have enabled the development of comprehensive, intensive diabetes regimens. To increase the success rate for patients and families with these regimens, it is imperative for the multidisciplinary diabetes team and the primary care clinician to work together to support and educate all those who help manage or affect patients. The pathogenesis of diabetes is reviewed in this article, emphasizing the nearness of expanding efforts at primary prevention and beta-cell preservation at the time of diabetes diagnosis. This is followed by an explanation of current and evolving diabetes management protocols, focusing on insulin regimens and delivery systems that can be used for children to improve glycemic control while minimizing hypoglycemia. Finally, the components of the outpatient visit are reviewed to elucidate methods of screening for diabetes complications to allow early intervention that provides …
Role of sympathoadrenomedullary system in cardiovascular response to stress in rats.

Sympathetic nerve and/or adrenal medulla contributions to stress-induced cardiovascular responses were investigated by factoring out their influence using adrenal demedullation (DMED) and/or chemical sympathectomy with guanethidine (GUAN). Rats divided into 4 groups [sham-operated/saline (SHAM/SAL), SHAM/GUAN, DMED/SAL and DMED/GUAN] were injected i.p. over 4 weeks with either saline or GUAN (25 mg/kg/day). At the end of this treatment period, blood pressure (BP) and heart rate (HR) were monitored via carotid catheter prior to and during restraint in conscious rats. Treatments did not alter basal BP or HR when compared to controls. Restraint increased HR (delta 72 bpm) and systolic, diastolic and mean BP (delta approximately 20 mm Hg) in control animals. Restraint-induced HR change was significantly greater in DMED/SAL animals (delta 88 bpm), but less in SHAM/GUAN animals (delta 40 bpm) than in controls. DMED/GUAN was not different from SHAM/GUAN alone in altering HR response to stress, supporting the greater influence of sympathetic nerves over adrenal medulla in controlling HR. Chronic GUAN abolished normal pressor responses to restraint stress. DMED increased diastolic blood pressure response to stress. However, in DMED/GUAN rats, not only did stress fail to increase blood pressure but rather stress produced hypotension (delta - 34 mm Hg MAP), demonstrating the role of adrenal medulla in maintaining BP during stress. Differential effects of the various treatments on diastolic and systolic pressure suggest that the treatments had effects on peripheral vasculature. These results demonstrate that sympathetic nerves and adrenal medulla have important influences on cardiovascular function during stress and that in the absence of either, the other system may partially compensate.(ABSTRACT TRUNCATED AT 250 WORDS)
Teaching imaginary children: University students’ narratives about their Latino practicum children

Abstract This study investigates the dialogic processes involved in how teachers talk about their students and what consequences their ways of talking (i.e., “narratives”) may have for their guidance. We take a sociocultural perspective on learning as transformation of students’ subjectivity. Teaching, as a process of guiding and facilitating learning, cannot be effective if the teacher does not actively seek how the student perceives and understands reality. We borrow and adapt from Bakhtin (1999) four narrative ways of talking about others: objectivizing, subjectivizing, problematizing and finalizing. The presence of these narratives in web discussion postings of our pre-service teachers about the Latino children they worked with in a community center are analyzed. We then compare their ways of talking about children with print- and web-based discussions about children made by in-service teachers, model teachers and our pre-service teachers in a school-based practicum. Using mixed quantitative and qualitative methodologies, we found an overwhelming predominance of objectivizing and finalizing in our pre-service teachers’ narratives about the children with whom they work that seems to define a certain pedagogical regime that we call here “teaching imaginary children/students.” This “way of talking” about children seems to be characterized by unchecked speculations guiding instruction that are not tested by finding out from the children themselves how they understand the instruction and the world. These speculations, in turn, can lead to a dogmatic approach towards children. We found another model of teaching/learning in ways that model teachers talk about their students based on a “community of learners” approach to instruction. This approach prioritizes subjectivizing and problematizing of students that can help to recursively correct the assumptions and preconceptions teachers may have of their students. Our own pre-service teachers were increasingly likely to subjectivize the Latino children over the course of the 9-week practicum. We suggest that the promotion of subjectivizing and problematizing of students should become a central part of the curriculum of pre-service teacher preparation and in-service teacher professional development programs. Without talking and listening to their students, teachers cannot know how the students think, feel, and perceive the world and themselves; in turn, it is very difficult for teachers to engage in collaboration with their students about learning.
Social Support and Success in Higher Education: The Influence of On-Campus Support on African American and Latino College Students

This study focuses on how personal support from the college environment influences the academic performance of African American and Latino college students attending selective colleges. Under-represented students at selective colleges continue to face challenges to their academic success, and support from the college environment is a key factor in the academic success of many of these students. The results indicate that it is important to distinguish between different forms of personal support and the race and gender of students receiving support. However, I find that the influence of faculty, specifically support from faculty of color, is important for the success of African American and Latino students at selective colleges.
The incidence of urinary incontinence across Asian, black, and white women in the United States

Objective We calculated incidence rates of urinary incontinence by incontinence frequency and type over 4 years in Asian, black, and white women in the United States. Study Design Prospective analyses included 76,724 participants aged 37–79 years in the Nurses' Health Study cohorts with no incontinence at baseline. Results The 4-year incidence of incontinence at least monthly was higher in white women (7.3/100 person-years) compared with Asian (5.7/100 person-years; P = .003) and black women (4.8/100 person-years; P P P Conclusion Urinary incontinence incidence differs by race. Studies to confirm these results and better understand underlying mechanisms are needed.
Tetradifon (TedionR): A specific inhibitor of Mg2+ dependent mitochondrial adenosine triphosphatase activity

An acaricide, tetradifon (TedionR), is a potent inhibitor of mitochondrial Mg2+ ATPase, 50% inhibition occurring at 5×10−8M for a fish brain homogenate preparation. Although the widely used ‘standard’ material, oligomycin, is somewhat more effective on mitochondrial Mg2+ ATPase, it is less specific than tetradifon to related ATPase enzymes. Tetradifon inhibited less than 20% of Na+K+ATPase over a wide range of concentrations, while oligomycin inhibited about 50% Na+K+ATPase at the concentration which gives nearly complete inhibition of mitochondrial Mg2+ATPase in the fish brain preparations.
Uncovering a Tumor Suppressor for Triple-Negative Breast Cancers

"Triple-negative" breast cancers are aggressive malignancies that respond poorly to treatments. Now Sun et al. (2011) find that the activity of the protein tyrosine phosphatase PTPN12 is lost in a large percentage of this breast cancer subtype, offering molecular drivers and possible therapeutic targets for this heterogeneous and intractable cancer.
Requirements of glycerol and fatty acid for triglyceride synthesis and ketogenesis by hepatocytes from normal and triiodothyronine-treated rats.

Abstract Hepatocytes from T3-treated rats synthesized less triglyceride and more ketone bodies from [1-14C]oleate at all concentrations from 0–2 mM, than did hepatocytes from euthyroid animals; addition of 1.0 mM glycerol increased triglyceride synthesis and reduced ketogenesis in hepatocytes from T3-treated rats to the rates observed in euthyroid hepatocytes in the absence of added glycerol. Glycerol did not alter triglyceride synthesis, but reduced ketogenesis by euthyroid hepatocytes. It is probable from these and other data (J. Biol. Chem. 259, 8857–8862 (1985)) that, in the hyperthyroid rat, glycero-3-P, and not fatty acid, is rate limiting for synthesis of triglyceride, and, secondarily for reducing rates of ketogenesis in the hepatocyte.
Conditions for boundedness in concave programming under reverse convex and convex constraints

In this paper, we are concerned with the problem of boundedness in the constrained global maximization of a convex function. In particular, we present necessary and sufficient conditions for boundedness of a feasible region defined by reverse convex constraints and we establish sufficient and necessary conditions for existence of an upper bound for a convex objective function defined over the system of concave inequality constraints. We also address the problem of boundedness in the global maximization problem when a feasible region is convex and unbounded.
Synaptic function of nicastrin in hippocampal neurons.

Synaptic dysfunction is widely thought to play a key role in the pathogenesis of Alzheimer’s disease (AD). Presenilins, the major gene products involved in familial AD, are essential for short- and long-term synaptic plasticity in mature neurons as well as for the survival of cortical neurons during aging. Presenilin and nicastrin are both indispensable components of the γ-secretase complex, but it remains unknown whether presenilin regulates synaptic function in a γ-secretase–dependent or γ-secretase–independent manner and whether nicastrin plays similar roles in central synapses. In the current study, we address these questions using an electrophysiological approach to analyze nicastrin conditional knockout (cKO) mice in the hippocampal Schaffer collateral pathway. In these mice, we found that, even at 2 mo of age, deletion of nicastrin in excitatory neurons of the postnatal forebrain using Cre recombinase expressed under the control of the αCaMKII promoter led to deficits in presynaptic short-term plasticity including paired-pulse facilitation and frequency facilitation. Depletion of Ca2+ in the endoplasmic reticulum mimics and occludes the presynaptic facilitation deficits in nicastrin cKO mice, suggesting that disrupted intracellular Ca2+ homeostasis underlies the presynaptic deficits. In addition, NMDA receptor-mediated responses and long-term potentiation induced by theta-burst stimulation were decreased in nicastrin cKO mice at 3 mo but not at 2 mo of age. Together, these findings show that, similar to presenilins, nicastrin plays essential roles in the regulation of short- and long-term synaptic plasticity, highlighting the importance of γ-secretase in the function of mature synapses.
Gaze and Attention Management for Embodied Conversational Agents

To facilitate natural interactions between humans and embodied conversational agents (ECAs), we need to endow the latter with the same nonverbal cues that humans use to communicate. Gaze cues in particular are integral in mechanisms for communication and management of attention in social interactions, which can trigger important social and cognitive processes, such as establishment of affiliation between people or learning new information. The fundamental building blocks of gaze behaviors are gaze shifts: coordinated movements of the eyes, head, and body toward objects and information in the environment. In this article, we present a novel computational model for gaze shift synthesis for ECAs that supports parametric control over coordinated eye, head, and upper body movements. We employed the model in three studies with human participants. In the first study, we validated the model by showing that participants are able to interpret the agent’s gaze direction accurately. In the second and third studies, we showed that by adjusting the participation of the head and upper body in gaze shifts, we can control the strength of the attention signals conveyed, thereby strengthening or weakening their social and cognitive effects. The second study shows that manipulation of eye--head coordination in gaze enables an agent to convey more information or establish stronger affiliation with participants in a teaching task, while the third study demonstrates how manipulation of upper body coordination enables the agent to communicate increased interest in objects in the environment.
Apoptolidins E and F, New Glycosylated Macrolactones Isolated from Nocardiopsis sp

Two new glycosylated macrolactones, apoptolidins E (5) and F (6), were isolated from fermentation of the actinomycete Nocardiopsis sp. and their structures assigned. Lacking the C16 and C20 oxygens of apoptolidin A (1), these macrolides are also the first members of this family to display a 4-O-methyl-l-rhamnose at C9 rather than a 6-deoxy-4-O-methyl-l-glucose.
Some Epipelagic Fishes of the North Pacific Ocean, Bering Sea, and Gulf of Alaska

Abstract In the course of salmon gill-netting operations in the North Pacific Ocean, Bering Sea, and Gulf of Alaska over a 7-year period, 37 species of fishes other than salmon have been captured incidentally. The catches of such species are listed by area and their relative abundance is calculated. Compared to salmon in the same localities, the incidental species are taken in small numbers and over limited ranges. Three species have heretofore been considered quite rare, another has been seen previously only in the South Pacific, and one may represent a new species. Several fishes show seasonal variations in distribution, possibly related to a preference for warmer water.
Stabilization and its Discontents: Argentina's Economic Restructuring in the 1990s

Abstract This paper assesses the Argentine stabilization and market reform strategies since 1989. We argue that Argentina may be penned in by its own success: exchange rate targeting quelled inflation but the resulting real appreciation has limited export and employment growth; microeconomic reforms raised efficiency but have threatened income distribution and hence political stability; exclusive styles of policy-making helped enact reform but have led to corruption and policy insensitivity and contributed to rising social discontent. We close by suggesting how a “second generation” of reforms could tackle these issues and spread the proceeds of reform to a wider segment of the Argentine public.
The relation of catabolite repression to the induction system for β-galactosidase in Escherichia coli

The effect of glucose on the constitutive synthesis of β-galactosidase following conjugation of an Escherichia coli Hfr strain carrying lac i+z+ genes with different F− strains was investigated. It was found that the addition of glucose to a glycerol-containing medium reduces the rate of synthesis of the enzyme to approximately one-half, not only in the merozygotes formed from two i−z− strains, but also in the merozygotes formed from a strain in which the i and z genes are deleted. In merozygotes formed from a third i−z− strain, glucose reduces β-galactosidase synthesis by 90%. This exceptionally strong effect of glucose is a trait of the recipient strain and is not specific for β-galactosidase. Identical results were found in analogous F-duction crosses. It was concluded that the i+z+/lacdel merozygotes are susceptible to catabolite repression immediately after the entry of i+z+ genes. Therefore, it appears that the i product has no role in catabolite repression. An oc mutation was also studied and found not to limit catabolite repression. It is suggested that the system by which the level of a catabolite controls the synthesis of messenger RNA specific for β-galactosidase in E. coli is distinct from the induction system for the lac operon.
High Rfsolution Fast Neutron Spectrometry without Time-of-Flight

Performance tests of a spectrometer tube of the type developed by Cuttler and Shalev show that the measurement of fast neutron spectra with this device can be made with an energy resolution previously obtainable only in large time-of-flight facilities. In preliminary tests, resolutions of 16.4 keV for thermal neutrons and 30.9 keV for 1-MeV neutrons were obtained. A broad-window pulse-shape discrimination (PSD) system is used to remove fram pulse-height distributions most of the continua due to 3He-recoil events, noise, and wall effect. Use of PSD improved the energy resolution to 12.9 keV for thermal neutrons and 29.2 keV for l-MeV neutrons. The detector is a viable tool for neutron research at nominally equipped accelerator laboratories.
A target-dose finding study of clozapine in patients with schizophrenia

Evidence from recent studies suggests that clozapine plasma concentrations greater than 350 ng/ml are correlated with therapeutic response. However, little is known about the clozapine dosages required to achieve these plasma concentrations. The purpose of this study was to determine if a target dose of 6 mg/kg/day of clozapine would produce a steady state plasma concentration of >350 ng/ml. Twelve patients with schizophrenia by DSM-III-R criteria who were refractory to treatment with standard antipsychotics were treated with clozapine utilizing a 10- to 14-day titration to a target dose of 6 mg/kg/day. The mean (±SD) clozapine plasma concentration achieved after 5 days at the target dose was 584 ± 417 ng/ml. Thus, although the target dose successfully produced therapeutic plasma concentrations for most patients, a wide variation was also apparent.
Focus groups as a group knowledge acquisition technique

Abstract Architectures and methodologies provide knowledge acquisition researchers and practitioners broad working frameworks within which to explore a variety of questions. However, in order to pursue the development of robust reasoning systems rigorously with reasonable expectations of the development process, empirical assessments of the knowledge acquisition process and of heuristic inputs to the process are essential. In this paper we discuss an experiment whose results support the use of a group knowledge acquisition technique in combination with other knowledge acquisition techniques.
Accessing the near-infrared spectral region with stable, synthetic, wavelength-tunable bacteriochlorins

The near-infrared (NIR) spectral region has been comparatively under-utilized for diverse materials and medical applications owing to the lack of chromophores that afford stability, solubility, synthetic malleability, and tunable photophysical features. Bacteriochlorins are attractive candidates in this regard; however, preparation via modification of naturally occurring bacteriochlorophylls or reduction of porphyrins or chlorins has proved cumbersome. To overcome such limitations, a dibromobacteriochlorin (BC-Br3Br13) was prepared de novo by the acid-catalyzed condensation of an 8-bromodihydrodipyrrin-acetal. BC-Br3Br13 bears (1) a geminal dimethyl group in each reduced ring to block adventitious dehydrogenation, and (2) bromo groups at the 3- and 13-positions for further chemical modifications. BC-Br3Br13 was subjected to four types of Pd-mediated coupling reaction (Suzuki, Stille, Sonogashira, dehalogenation) to give bacteriochlorins bearing substituents at the 3- and 13-positions (phenyl, vinyl, acetyl, phenylethynyl), and a benchmark bacteriochlorin lacking such substituents. The 3,13-divinylbacteriochlorin was transformed to the 3,13-diformylbacteriochlorin. Depending on the substituents at the 3- and 13-positions, the position of the long-wavelength absorption maximum (Qy(0,0) band) lies between 713 and 771 nm, the fluorescence emission maximum lies between 717 and 777 nm, and the fluorescence quantum yield ranges from 0.15 to 0.070. The ability to introduce a wide variety of functional groups via Pd-mediated coupling reactions and the tunable absorption and emission spectral properties suggest that synthetic bacteriochlorins are viable candidates for a wide variety of photochemical applications.
The biogeochemistry of nutrients and trace metals in Hood Canal, a Puget Sound fjord

Abstract The summer stratification of the surface layer of much of Hood Canal (a Puget Sound fjord) results in a surface layer low in nutrients and a deep layer low in dissolved oxygen and enriched in nutrients. Deviations from the dissolved oxygen:nutrient linear relationships are manifestations of several chemical and biological processes. The low dissolved oxygen concentrations (50 μmol) result in the redistributions of Fe in the sediment column while Mn is redistributed within the water column. Trace metals are also taken up by organisms in the surface layer and regenerated in the deep layer in the order Zn>>Cd>Cu=Ni Regenerated Zn is adsorbed on to resuspended bottom sediments that are enriched in Fe oxyhydroxides while Cd is adsorbed throughout the water column. Particulate distributions of Cu and Ni indicate these metals are also participating in biogeochemical cycles, albeit to a lesser extent.
Inhibitors of nitrogen fixation in extracts from Clostridium pasteurianum.

Abstract The gases H2, CO, N2O, and NO specifically inhibited the “nitrogenase” system in extracts from Clostridium pasteurianum. Concentrations of inhibitor effective against N2 fixation did not substantially inhibit pyruvate metabolism. All the inhibitors acted competitively, although H2 inhibition was uncompetitive at a higher than optimal phosphate concentration. Evacuation, following preincubation with the gaseous inhibitors, relieved all inhibitions. Cyanide and azide were weak inhibitors of N2 fixation. These results are discussed with respect to the nature of the N2-binding site and the mechanism of N2 fixation.
The kinetics of exchange between americium(III) and europium ethylenediaminetetraacetate

Abstract The kinetics of exchange has been studied for Am3+ and EuEDTA− in an aqueous solution of 0·1 M total ionic strength with acetate buffer. It was found that the kinetic equation involved both acid dependent and acid independent terms. Possible mechanisms consistent with the complete rate equations of the two (acid dependent and acid independent) paths are proposed. The two paths have approximately equal probability at pH 6·4. An increase in the acetate buffer concentration increases the rate of the acid dependent pathway but decreases that of the acid independent one. The effects of buffer concentration can be explained in terms of complexation by acetate of either the free metal ions or the metal-EDTA complex.