cssi/SciSciGPT-SciSciNet huggingface dataset:
Animal model of autism based on developmental data

Animal models of human brain damage syndromes range from ones that are purely theoretical to ones that attempt to duplicate a human syndrome at every level. The similarity between animal and human cases in experimental manipulation, CNS alteration, and tests of parallelism is sometimes restricted by the extent to which experimental species match humans in their basic biology. However, the information available from the human condition is often the most important limiting factor in the degree to which similarities can be achieved. The recent discovery of a high rate of autism in patients exposed to thalidomide around the time of neural tube closure suggests an appropriate experimental manipulation for an animal model of the disease. Rats exposed to valproic acid at the same stage of development mimic the thalidomide cases' apparent injuries to the brain stem. Whether the behavior of these brain-damaged animals is similar to that observed in autism is difficult to determine, because the diagnostic behavioral features of the disease are not easily translated into animal tasks. However, anatomical observations in human cases provide tests of parallelism that can be applied to animals, and these appear to be positive in the animal model. The development of behavioral tests that discriminate “autistic behavior” from that of other brain damage syndromes may require further research in both humans and animals. © 1997 Wiley-Liss, Inc.
Effects of liquid holding on the induction of mutations in an ultraviolet-sensitive strain of Aspergillus nidulans.

Abstract It has been shown that a mutation to UV-sensitivity ( uvs -I) has the effect of reducing the yield of adenine-independent mutants in Aspergillus nidulans whether the comparison is made on the basis of dose or survival. Methionine-independent mutants were induced with a greater frequency only at higher doses of UV and lower levels of survival. When the uvs -I strain is held at 25° in buffer following UV treatment, survival increases to a maximum at between 48 and 96 h. The level of survival attained by the UV-sensitive mutant during liquid holding is equivalent to that observed with a uvs + strain plated immediately following UV treatment or after 96 h of liquid holding. The uvs -I mutation allows for the expression of liquid-holding repair of UV damage in A. nidulans . The yield of both adenine- or methionine-independent mutants based on survival increased during liquid holding of the uvs -I strain to a level greater than that observed in an equivalent uvs + strain. The yield of adenine- or methionine-independent mutants in the uvs + strain was not altered significantly during liquid holding. We interpret the uvs -I mutant of A. nidulans to represent a regulatory mutation in a function concerned with the repair of radiation damage which in addition to affecting the rate of repair leads to reduced fidelity of repair.
Guilds, Boards, and Hobgoblins

Abstract The American specialty board system is viewed in the historical perspective of a quest for quality assessment of surgical trainees. Beginning with the American Board for Ophthalmic Examinations in 1916, a system of 22 boards has developed which, by their training requirements and examinations, essentially dictate the length and content of all postgraduate educational programs. The time has come for the boards, as a powerful force in postgraduate education and in organized medicine, to reassess their position and to be sensitive to the responsibilities they have for the future. The events of history suggest six changes that might be profitable. (1) Recognize their purpose to be broader than the administration of certifying examinations. (2) Recognize that the certificate is now a license, and deal squarely with this issue. (3) Initiate and support needed medical reforms while the private sector can still do so. (4) Assume a leadership role in the shaping and future direction of graduate medical education. (5) Relinquish a degree of autonomy in order to strengthen the American Board of Medical Specialties. (6) Define their place in the medical scene and reorganize their board structures accordingly. The primary responsibility of the boards should be to make certain all aspects of resident training in approved programs are sound. Long-range goals should be the elimination of the certifying examination, and public recognition and approval of specialty status attainment.
Fluorescence Quenching of CdTe Nanocrystals by Bound Gold Nanoparticles in Aqueous Solution

Water-soluble gold nanoparticles with an average diameter of 5 nm were prepared with carboxylic acid terminated thiol ligands. These ligands contain zero to eight methylene moieties. CdTe nanocrystals with an average diameter of 5 nm were synthesized with aminoethanethiol capping. These nanocrystals displayed characteristic absorption and emission spectra of quantum dots. The amine terminated CdTe nanocrystals and carboxylic-acid-terminated gold nanoparticles were conjugated in aqueous solution at pH 5.0 by electrostatic interaction, and the conjugation was monitored with fluorescence spectroscopy. The CdTe nanocrystals were significantly quenched upon binding with gold nanoparticles. The quenching efficiency was affected by both the concentration of gold nanoparticles in the complex and the length of spacer between the CdTe nanocrystal and Au nanoparticle. The observed quenching was explained using Forster resonance energy transfer (FRET) mechanism, and the Forster distance was estimated to be 3.8 nm between the donor–acceptor pair.
Photospheric Subrotation Differential Rotation and Zonal Wind Bands - a Reverse Pirouette

It is noted that on the sun the core is assumed to be rotating with a period of about 12 days while the overlying 'mantle' convection zone has a solid body component of about 27 days. It is proposed that this phenomenon could simply be understood as a 'reverse pirouette'. It is noted that while previously proposed models provide solutions of valid equations and computer analyses, they lack a simple physical picture to explain the phenomenon. In the model proposed here, the solar oblateness is conventionally providing added heat input at the poles. The result is the large scale transport of material toward the equator, causing subrotation. The model is thus seen as facilitating an understanding of the formation of a slowly rotating convection zone above the more rapidly rotating core. The latitudinal photospheric differential rotation is interpreted as a 'second order' effect associated with the horizontal transport of momentum.
The bithorax complex--a model for cell determination in Drosophila.

Abstract The bithorax complex is postulated to be the structural gene for an allosteric protein whose function is to translate a position in the developing egg into the expression of a unique set of genes characterizing the determined state of cells arising in that region of the egg. This is accomplished through the binding of inducer molecules, which exist in an anterior-posterior gradient in the egg, to the allosteric bithorax protein. Depending upon the nature of the inducer binding sites occupied, an expressor binding site on the bithorax protein is activated to one of a number of possible states. Depending upon the state of the expressor binding site, the bithorax protein binds to one of a number of classes of expressors. Binding of the bithorax protein to an expressor leads to the expression of those genes controlled by the expressor.
Surface Reconstruction of In Vivo Geometry Based on Medical Images Using Multilevel Radial Basis Functions

Compactly supported radial basis functions (RBFs) were used for surface reconstruction of in vivo geometry, translated from two dimensional (2D) medical images. RBFs provide a flexible approach to interpolation and approximation for problems featuring unstructured data in three-dimensional space. Point-set data are obtained from the contour of segmented 2-D slices. Multilevel RBFs allow smoothing and fill in missing data of the original geometry while maintaining the overall structure shape.Copyright © 2004 by ASME
VELOCITY DEPENDENCE OF ATOMIC STATE POPULATIONS IN HIGHLY STRIPPED ATOMS

INTRODUCTION In the past few years, the strong hyperfine fields in few electron atoms of light nuclei have been effectively utilized to make precise g-factor measurements, by using the recoil distance method for time differential studiesl). , This elegant method is limited, however, to nuclei with rather low spin because of the small size of the atomic perturbation for large I. We have developed a method to overcome this difficulty by partially decoupling the atomic h.f.i. with a large external magnetic field, producing much larger oscillations in the gamma ray anisotropy. As a test case, we have chosen the 4iCa(15/2 +) state, where the g-factor is known from previous external field measurement 2), in order to measure h.f. field of the highly stripped atom.
Collaboration in the cloud and online education environments

Cloud computing is attractive [1-3] from several points of view for next generation online education. There are many jobs [4, 5]. It supports shared information repositories as well as sharing the real time and asynchronous interaction between teachers and learners. The promise of virtual universities in the cloud has been highlighted by the growing interest in MOOC's (massive open online courses) which are naturally hosted on clouds. The basic delivery model of MOOC's is reasonably traditional with the scaling of clouds added. However MOOC's emphasize new collaboration models for the interaction between mentors (graders, teachers) and students. Further “laboratories” are typically used in many classes and we discuss the use of clouds to support computing labs attached to computer science and related classes. We suggest that MOOC technology can be used in different ways. Rather than single classes aimed at many students, we suggest that an alternative is multiple classes customized for different communities. Here we have a MOOC lesson repository (in the cloud) and technology like Google Course Builder to construct different “play lists” corresponding to the different classes. This has been implicitly used in past with “PowerPoint” presentations placed on the web and then re-used in different ways However often PowerPoint is hard to re-use and it seems more promising to re-use the MOOC lesson with presentation and recorded lecture.
Student and School Staff Strategies to Combat Cyberbullying in an Urban Student Population

Research indicates that cyberbullying is occurring among middle and high school student populations at increasing rates. There is limited research, however, on strategies students use to combat cyberbullying, as well as how schools implement policies, intervention tactics, and prevention strategies. This qualitative study aimed to explore, among a sample of middle and high school students and staff, the strategies used at the individual student and schoolwide levels to prevent and combat cyberbullying behavior.
Natural convection in narrow-gap, spherical annuli

Abstract The subject of this paper is natural convection of fluid contained within narrow-gap, spherical annuli. The flows are presumed to be steady and the fluid is assumed to follow the Oberbeck-Boussinesq model. With the gap being very small relative to the outer sphere's radius, the dependent variables are solved for by using a regular perturbation method in powers of the relative gap width, e. Solutions were found for a heated outer sphere through terms of order ϵ 11 . The results include Nusselt numbers, and contours of streamlines and isotherms as functions of the Grashof and Prandtl numbers, e, and Q, the dimensionless uniform energy generation rate parameter. The value of ϵ ranged from 0.1 to 0.001, Pr from 0.01 to 10, and Gr from 7 × 10 6 to 5 × 10 12 .
Effect of an Altitude-Dependent Background Atmosphere on Shuttle Plumes

T HE shuttle ionospheric modification with pulsed localized exhaust (SIMPLEX) experiments conducted by the Naval Research Laboratory (NRL) were designed to 1) assess the effects of rocket exhaust interactions in the ionosphere and 2) mimic large ionospheric disturbances that occur naturally [1–5]. These experiments use space shuttle orbital maneuver subsystem (OMS) engines to inject exhaust over ground radar sites. The shuttle exhaust provides a high-speed neutral gas that streams through the ambient plasma of the ionosphere. The neutral exhaust molecules exchange chargewith ambient O ions in the ionosphere. This interaction between the plasma and neutrals results in the formation of ion-ring and beam velocity distributions of plasma particles in the ionosphere. During the SIMPLEX experiments, these distributions are studied with ground radars using incoherent scatter of radio waves from electrons in the ionosphere. To date, six SIMPLEX burns [1–5] have been conducted over incoherent scatter radar sites at various locations, as shown in Table 1. In these experiments, the relative velocity between the ambient ions and injected neutrals is much faster than that which occurs naturally in any region of the ionosphere. Auroral electric fields can accelerate ions to velocities between 0.5 and 2:5 m=s [6]. The neutral injections from the space shuttle in orbit yield exhaust velocities of between 4.7 and 10:7 km=s relative to the background neutrals and ions. During the shuttle burn experiments, the highspeed neutrals chemically react with the stationary plasma. During auroral plasma convection, however, the high-speed ambient O ions and electrons in the ionosphere (accelerated to a high velocity by auroral electric fields) chemically react with stationary neutral molecules or atoms [5,6]. Consequently, the primary difference between high-speed plasma convection and space shuttle OMS burns is the reference frame for the relative ion and neutral motion [5]; both phenomena result in the formation of ring-beam ion velocity distributions. The SIMPLEX experiments were designed to reproduce the naturally occurring ion-ring distributions, which can create ionospheric instabilities leading to regions of plasma turbulence. In addition, the experiments also provide a unique way to examine gas-phase physical and chemical phenomena in the hypersonic and hyperthermal energy regime, which is relatively unstudied and difficult to reproduce in a laboratory [7]. The first step to modeling the ionospheric interactions of space shuttle exhaust is to describe the neutral flow from the exit plane of the shuttle OMSengines into the expanse of the upper atmosphere. In this paper, we use the direct simulation Monte–Carlo (DSMC) method [8] to simulate the shuttle burn and to study the interaction between the shuttle exhaust and the neutral species of the background atmosphere. In the following sections, we present simulation results showing the time evolution of the shuttle plume and background, and we discuss the effect of the altitude-dependence of the background atmosphere.
Unusual behavior of Hgl−xCdxTe and its explanation☆

Abstract This paper involves an unusual semiconductor alloy, Hg l−x Cd x Te, a breakdown of the Virtual Crystal Approximation (VGA) in that alloy (the first such breakdown in a semiconductor alloy), the success of the Coherent Potential Approximation (CPA), the “first order” explanation of these results in terms of energies of atomic valence levels, and the qualitative explanation of the unusual properties of Hg l−x Cd x Te in terms of the results reported above. The genesis of the work was the use of photoemission spectroscopy. Cd and Hg core shifts are detected as a function of alloy composition and related to bonding concepts developed here.
Activated type 2 innate lymphoid cells regulate beige fat biogenesis

Type 2 innate lymphoid cells (ILC2s), an innate source of the type 2 cytokines interleukin (IL)-5 and -13, participate in the maintenance of tissue homeostasis. Although type 2 immunity is critically important for mediating metabolic adaptations to environmental cold, the functions of ILC2s in beige or brown fat development are poorly defined. We report here that activation of ILC2s by IL-33 is sufficient to promote the growth of functional beige fat in thermoneutral mice. Mechanistically, ILC2 activation results in the proliferation of bipotential adipocyte precursors (APs) and their subsequent commitment to the beige fat lineage. Loss- and gain-of-function studies reveal that ILC2- and eosinophil-derived type 2 cytokines stimulate signaling via the IL-4Rα in PDGFRα(+) APs to promote beige fat biogenesis. Together, our results highlight a critical role for ILC2s and type 2 cytokines in the regulation of adipocyte precursor numbers and fate, and as a consequence, adipose tissue homeostasis. PAPERCLIP:
Strong Inference: Certain systematic methods of scientific thinking may produce much more rapid progress than others

Scientists these days tend to keep up a polite fiction that all science is equal. Except for the work of the misguided opponent whose arguments we happen to be refuting at the time, we speak as though every scientist's field and methods of study are as good as every other scientist's, and perhaps a little better. This keeps us all cordial when it comes to recommending each other for government grants. But I think anyone who looks at the matter closely will agree that some fields of science are moving forward very much faster than others, perhaps by an order of mag­ nitude, if numbers could be put on such estimates. The discoveries leap from the head­ lines - and they are real advances in complex and difficult subjects, like molecular biology and high-energy physics. As Alvin Weinberg (1964), says "Hardly a month goes by without a stunning success in molecular biology being reported in the Proceed­ ing of the National Academy of Science." Why should there be such rapid advances in some fields and not in others? I think the usual explanations that we tend to think of-such as the tractability of the subject, or the quality or education of the men drawn into it, or the size of research contracts are important but inadequate. I have begun to believe that the primary factor in scienSource: Science (1965), 146:347-353. Copyright 1965 by the American Association for the Advancement of Science and reprinted by permission.
Bird-habitat relationships in a Texas estuarine marsh during summer

Birds were surveyed during summer 1985 in five adjacent saline vegetation zones and during summers 1986 and 1991 in 6 adjacent vegetation zones on the San Bernard National Wildlife Refuge on the upper Texas Coast. Although 66 bird species were recorded, numbers and species varied among years, and only 17 were nesting species. A few bird species used all vegetation types at some time, but most were limited by vegetation structure or water presence. Olney’s three-square bulrush (Scirpus olneyi), saltgrass (Distichlis spicata), and mudflats were especially favored feeding and resting areas in response to periodic flooding and had the greatest frequency of use as well as species richness. Reduced rainfall and water depths during 1986 were reflected in a change toward birds favoring drier conditions. Heavy rainfall in 1991 decreased diversity but increased usage and favored freshwater and swimming birds. Although tidally influenced wetlands often are considered uniform, dynamic water and salinity regimes observed along this coast must be considered in the design of any management or conservation program.
Regenerating Mammalian Nerve Fibres: Changes in Action Potential Waveform and Firing Characteristics Following Blockage of Potassium Conductance

Extracellular application of potassium channel blocking agents is known to increase the amplitude and duration of the compound action potential in non-myelinated and demyelinated axons, but not in mature mammalian myelinated fibres. In the present study we used intra-axonal and whole nerve recording techniques to study the effects of the potassium channel blocking agent 4-aminopyridine (4-AP) on regenerating rat nerve fibres. Our results indicate that early regenerating (premyelinated) axons show considerable broadening of the action potential after 4-AP application and late regenerating (myelinated) axons give rise to burst activity following a single stimulus after 4-AP application. 4-AP did not affect spike waveform or firing properties of normal mature sciatic nerve fibres. These results demonstrate the importance of potassium conductance in stabilizing firing properties of myelinated regenerating axons.
Field Emission: Large Current Densities, Space Charge, and the Vacuum Arc

Field emission was obtained from a single crystal tungsten emitter under conditions of very high vacuum and clean surfaces. The geometry of the emitter was determined by electron microscopy permitting accurate calculation of both the surface electric field and an average current density. The use of pulse electronic techniques extended the observations to the upper limit of the current densities for which the normal field emission was stable. Above this limit an explosive vacuum arc occurred between electrodes. From these experiments the following conclusions were drawn. (1) The wave mechanical, image force corrected theory quantitatively predicted the observed average current density up to that density for which space charge dominated the emission. (2) Space charge was effective at a current density of the order of 107 amperes/cm2, where a marked deviation occurred from the usual current-voltage relationship. Space charge effects permitted the simultaneous operation of multiple emitting areas of differing geometries. (3) At a still higher critical current density in the range 107 to 108 amperes/cm2, a field emission initiated vacuum arc occurred between electrodes resulting in a change of emitter geometry. Current density was the dominant criterion for the initiation of the vacuum arc.
Insights into the nitric oxide reductase mechanism of flavodiiron proteins from a flavin-free enzyme

Flavodiiron proteins (FDPs) catalyze reductive scavenging of dioxygen and nitric oxide in air-sensitive microorganisms. FDPs contain a distinctive non-heme diiron/flavin mononucleotide (FMN) active site. Alternative mechanisms for the nitric oxide reductase (NOR) activity consisting of either protonation of a diiron-bridging hyponitrite or "super-reduction" of a diferrous-dinitrosyl by the proximal FMNH(2) in the rate-determining step have been proposed. To test these alternative mechanisms, we examined a deflavinated FDP (deflavo-FDP) from Thermotoga maritima. The deflavo-FDP retains an intact diiron site but does not exhibit multiturnover NOR or O(2) reductase (O(2)R) activity. Reactions of the reduced (diferrous) deflavo-FDP with nitric oxide were examined by UV-vis absorption, EPR, resonance Raman, and FTIR spectroscopies. Anaerobic addition of nitric oxide up to one NO per diferrous deflavo-FDP results in formation of a diiron-mononitrosyl complex characterized by a broad S = (1)/(2 )EPR signal arising from antiferromagnetic coupling of an S = (3)/(2) {FeNO}(7) with an S = 2 Fe(II). Further addition of NO results in two reaction pathways, one of which produces N(2)O and the diferric site and the other of which produces a stable diiron-dinitrosyl complex. Both NO-treated and as-isolated deflavo-FDPs regain full NOR and O(2)R activities upon simple addition of FMN. The production of N(2)O upon addition of NO to the mononitrosyl deflavo-FDP supports the hyponitrite mechanism, but the concomitant formation of a stable diiron-dinitrosyl complex in the deflavo-FDP is consistent with a super-reduction pathway in the flavinated enzyme. We conclude that a diiron-mononitrosyl complex is an intermediate in the NOR catalytic cycle of FDPs.
Effective Practices for Developing the Literacy Skills of English Language Learners in the English Language Arts Classroom

This paper is a review of literature presenting instructional strategies—based on normative as well as empirical arguments—which have proven to be effective in envisioning what all teachers need to know and be able to do to teach English language arts (ELA) to English language learners (ELLs). The studies selected for review address what is particular to teaching ELA to ELLs. The paper is divided into two main sections: (a) teachers' linguistic practices and (b) teachers' pedagogical practices. In the first section, we report on the studies that analyze teachers' understanding of linguistics and present implications for their instruction of ELLs. Three areas of effective practice are emphasized based on the particular aspects of teaching ELA to ELLs. The first area is that teachers should recognize that literacy skills in ELLs' native languages might influence the ways in which ELLs process linguistic information in English. The second area highlights the argument that teachers should find ways to facilitate ELLs' mastery of academic vocabulary. The third area covers the significance of enhancing ELLs' metacognitive reading skills. In the second section, on teacher pedagogical practices, we discuss two broad pedagogical skills that emerge from both the normative and empirical studies reviewed and are closely related: (a) the teachers' ability to help ELLs construct meaning from the texts or speech represented in the ELA classroom and (b) the teachers' ability to engage ELLs in actively learning to read and write. The paper ends with a summary and a brief reflective statement on the limitations of the review of the literature.
A Non-Extractive Method for the Quantitative Estimation of Chlorophyll in Algal Cultures

THE standard method for the quantitative estimation of chlorophyll usually involves the extraction of this fat-soluble pigment in either ether, acetone, or alcohol. When quantities of chlorophyll are large, as is frequently found in culture experiments, large errors may result from incomplete extraction.
Estrogen-Related Receptor α (ERRα) is required for adaptive increases in PGC-1 isoform expression during electrically stimulated contraction of adult cardiomyocytes in sustained hypoxic conditions

Abstract Background and objectives In adult myocardium, Estrogen-Related Receptor α (ERRα) programs energetic capacity of cardiomyocytes by regulating expression of target genes required for mitochondrial biogenesis, fatty acid metabolism and oxidative phosphorylation. Transcriptional activation by ERRα is dependent on the α or β isoform of Peroxisome Proliferator-Activated Receptor γ Coactivator-1 (PGC-1). This study utilized a model of continuously contracting adult cardiomyocytes to determine the effects of sustained oxygen reduction (hypoxia) on ERRα target gene expression. Methods and results Adult feline cardiomyocytes in primary culture were electrically stimulated to contract at 1Hz in either normoxia (21% O 2 ) or hypoxia (0.5% O 2 ). Compared to normoxia, hypoxia increased PGC-1α mRNA and PGC-1β mRNA levels by 16-fold and 14-fold after 24h. ERRα mRNA levels were increased 3-fold by hypoxia over the same time period. Treatment of cardiomyocytes with XCT-790, an ERRα inverse agonist, caused knockdown of ERRα protein expression. The increases in PGC-1 mRNA levels in response to hypoxia were blocked by XCT-790 treatment, which indicates that expression of PGC-1 isoforms is dependent on ERRα activity. The products of two ERRα target genes required for energy metabolism, Cox6c mRNA and Fabp3 mRNA, increased by 4.5-fold and 3.5 fold after 24h of hypoxia as compared to normoxic controls. These increases were blocked by XCT-790 treatment of hypoxic cardiomyocytes with a concomitant decrease in ERRα expression. Conclusions ERRα activity is required to increase expression of PGC-1 isoforms and downstream target genes as part of the adaptive response of contracting adult cardiomyocytes to sustained hypoxia.
Insulin reverses the growth retardation effect of phorbol ester in chicken embryos during organogenesis

Abstract The tumor promoting phorbol esters can affect early embryonic development by causing interference with the normal pathways of cellular growth and differentiation. The present study was designed to: a) define a time in organogenesis when a vertebrate embryo model, the chicken, was sensitive to the phorbol ester 12-0-tetradecanoil-13-acetate (TPA), and b) attempt a rescue of the embryos disturbed by TPA with simultaneous addition of insulin. In embryos treated at days 2 and 3 of development, TPA caused dose-dependent mortality. Survivors were biochemically retarded as indicated by their decreased weight, protein, DNA, RNA, total creatine kinase, triglycerides, phospholipids and cholesterol contents. When intermediate doses of TPA (50 ng/embryo) were applied together with insulin (100 ng/embryo), the embryonic growth disturbance was largely antagonized. These data, generated with an in vivo whole embryo, support the strong link between the mode of action of insulin and signal transduction mechanisms typical of phorbol esters.
In vitro cell culture infectivity assay for human noroviruses.

Human noroviruses cause severe, self-limiting gastroenteritis that typically lasts 24–48 hours. Because of the lack of suitable tissue culture or animal models, the true nature of norovirus pathogenesis remains unknown. We show that noroviruses can infect and replicate in a 3-dimensional (3-D), organoid model of human small intestinal epithelium. Cells grown on porous collage-coated beads under fluid shear conditions in rotating wall vessel bioreactors differentiate into 3-D architectures resembling both the morphologic and physiologic function of in vivo tissues. Microscopy, PCR, and fluorescent in situ hybridization provided evidence of norovirus infection. Cytopathic effect and norovirus RNA were detected at each of the 5 cell passages for genogroup I and II viruses. Our results demonstrate that the highly differentiated 3-D cell culture model can support the natural growth of human noroviruses, whereas previous attempts that used differentiated monolayer cultures failed.
Mouse conceptuses have a limited capacity to elevate the mRNA level of cellular retinoid binding proteins in response to teratogenic doses of retinoic acid

In these studies, we wished to determine the effect of teratogenic doses of retinoic acid on the expression of cellular retinoic acid binding protein I (CRABP-I) mRNA, cellular retinoic acid binding protein II (CRABP-II) mRNA, cellular retinol binding protein I (CRBP-I) mRNA, and cellular retinol binding protein II (CRBP-II) mRNA in mouse conceptuses. Levels of CRABP-II mRNA and CRBP-I mRNA were modestly elevated (2.5-fold and 1.5-fold, respectively) in 9-day gestation conceptuses following treatment of dams with 100 mg/kg b.w. of retinoic acid. These levels were elevated by 6 hr following treatment and remained elevated until 48 and 24 hr, respectively. Two other retinoids, etretinate and retinoyl beta-glucuronide, also moderately elevated CRABP-II mRNA and CRBP-I mRNA levels in conceptuses. In contrast, the levels of CRABP-I mRNA in the conceptuses remained unaffected by treatment with any of these three retinoids. These results demonstrate that conceptuses have a limited capacity to elevate the cellular retinoid binding proteins mRNA levels and presumably the synthesis of their respective proteins in response to high, teratogenic doses of retinoic acid. As a result, an excess of free retinoic acid becomes available to the nuclear retinoic acid receptors, which may lead to inappropriate gene expression and eventual maldevelopment.
The Contextual Experiences of Rural Custodial Grandparents and Opportunities for Social Work

Rural custodial grandparents have been understudied. As the grandparent caregiving population increases, more attention is needed to understand custodial grandparents in rural settings. This article explores the state of knowledge of the experiences of rural grandparents. A systematic review of the caregiving literature is conducted to understand the issues affecting this caregiving population. The results suggest that rural grandparents often are minority grandmothers with limited resources who provide care to older grandchildren in isolated environments. Attention is given to the social ecological framework as one model that can help to inform how social workers intervene with this population. Recommendations are offered for social work research, practice, and policy.
Undergraduate Men's and Women's Responses to Positive and Negative Feedback about Academic Performance:

Similarities and differences between the sexes in response to evaluative feedback about academic performance were examined from a symbolic interactionist standpoint. Undergraduate men's and women's...
Interferon receptors and the caspase cascade regulate the antitumor effects of interferons on human pancreatic cancer cell lines.

Abstract Background Interferons (IFNs) have antiproliferative effects on tumor cells. The apoptotic effects and sensitization to chemotherapy conferred by IFN therapy, however, are not clearly understood. The aims of the present study were to explore the apoptotic effects of IFNs in human pancreatic cancer cell lines and to attempt to define their ability to synergistically enhance sensitivity to 5-fluorouracil (5-FU) and gemcitabine, a mechanism that depends on the expression of IFN receptors. Methods Human pancreatic cancer cells were cultured alone or in combination with the chemotherapeutic agents 5-FU and gemcitabine. Differential dosages of IFN-α, -β, and -γ were also added to the cell lines concomitantly during a period of 24 to 96 hours. The cell line viability and effects of treatment were examined using the methylthiazol tetrazolium assay and single-stranded DNA apoptosis assay. The expression of IFN receptors was determined using immunohistochemistry. Caspase-8 inhibitor was used to block the caspase cascade. Results The antiproliferative and apoptotic effects of IFNs were most profoundly demonstrated on those cells that expressed the respective IFN receptor. The apoptotic effects provided by the interferons, however, were blocked by caspase-8 inhibition. The addition of IFNs significantly enhanced the cytotoxic effects of 5-FU and gemcitabine in those cell lines that expressed the corresponding IFN-α, -β, or -γ receptors. Conclusions This study on pancreatic cancer cell lines has demonstrated that IFNs mediate apoptosis through IFN receptors and the caspase cascade. Enhanced cytotoxicity occurred when IFNs were combined with 5-FU and gemcitabine.
A prolonged QRS duration on surface electrocardiogram is a specific indicator of left ventricular dysfunction

Abstract Objective. We sought to determine whether a prolonged QRS interval duration is associated with decreased left ventricular (LV) systolic function. Background. The 12-lead electrocardiogram (ECG) is a routine test for suspected cardiac disease. Although several scoring systems have been devised to estimate LV systolic function, no studies have examined the direct relationship between QRS duration alone and LV systolic function. Methods. We analyzed the standard 12-lead surface ECG of 270 consecutive patients, referred for radionuclide ventriculography. Patients (n = 44) with bundle branch blocks, atrial flutter or fibrillation, pacemaker rhythm, recent myocardial infarction or bypass surgery, and patients on antiarrhythmic drugs were excluded. In the remaining patients (n = 226), we correlated the QRS duration on standard resting ECG, and the resting LV ejection fraction (EF), end-systolic and end-diastolic counts (ESC and EDC, respectively; LV volume indices), as obtained by radionuclide angiography. We used a multivariate analysis to identify independent predictors of reduced ventricular function entering QRS duration, the previously described R-wave score and clinical variables in our model. Results. The QRS duration in the abnormal EF group was significantly longer than in the normal EF group (0.102 vs. 0.091 s, p 0.10 s was highly specific (83.6%), but modestly sensitive (43.8%), for the prediction of abnormal EF. Furthermore, an abnormal EF was predicted with incrementally increased specificity (83.6% to 99.3%) and a corresponding decrease in sensitivity (43.8% to 13.8%) for each 0.01-s increase in the definition of prolonged QRS (from >0.10 to >0.12 s). Accordingly, the positive likelihood ratio for the prediction of decreased LV function was increased from 2.67 to 19.7 as the definition of prolonged QRS duration was increased from >0.10 to >0.12 s. In the multivariate analysis, a prolonged QRS duration and a low R-wave score were the only independent predictors of decreased LV systolic function. Conclusions. Prolonged QRS duration (>0.10 s) obtained from a standard resting 12-lead ECG is a specific, but relatively insensitive indicator of decreased LV systolic function. Further prolongation of the QRS had a higher specificity for decreased LV EF and a higher positive likelihood ratio for predicting abnormal LV EF.
Effects of prostacyclin and its stable analog, iloprost, upon insulin secretion in isolated pancreatic islets.

Abstract We investigated the effects of prostacylin in three concentrations of 2.7 nM, 53.8 nM and 267 nM on insulin release by isolated rat islets. The lowest concentration produced no significant effects. The middle concentration led to stimulation followed by inhibition of the reaction studied, while the highest concentration strongly depressed insulin release. These effects of prostacyclin appeared to be specified, because they were mimicked by its stable analog, iloprost, but not by its metabolite, 6-keto-PGF 1α . The results suggest that prostacyclin generated in islets might exert locally an influencing upon insulin release.
Dietary B vitamin needs of strains of pigs with high and moderate lean growth

Ten sets of 5 littermate pigs from each of 2 genetic strains were utilized to determine the impact of the dietary concentration of 5 B vitamins (riboflavin, niacin, pantothenic acid, cobalamin, and folacin) on growth from 9 to 28 kg of BW in pigs with high or moderate capacity for lean growth. All pigs (penned individually) were reared via a segregated, early weaning scheme, so that the lean growth potential of each strain could be expressed. The basal diet provided the 5 test vitamins at concentrations of total and estimated bioavailability equivalent to a minimum of 100 and 70%, respectively, of their estimated requirements (NRC, 1998) for 5- to 10-kg pigs. At a BW of 9 +/- 0.9 kg, pigs within each litter were allotted to the basal diet supplemented with sources of the 5 test vitamins equivalent to an additional 0, 100, 200, 300, or 400% (bioavailable) of the NRC requirements. Pigs from the high lean strain consumed less feed (P 470% of NRC, 1998) vs. moderate (270%) lean strain. Based on these data, the dietary needs for 1 or more of the 5 B vitamins are greater than current NRC (1998) estimates, particularly in pigs expressing a high rate of lean tissue growth. The greater need for these vitamins is not associated with greater dietary energy intake or body energy accretion rate but is potentially due to shifts in the predominant metabolic pathways.
Cell encapsulation in a magnetically aligned collagen-GAG copolymer microenvironment

Engineered tissue microenvironments impart specialized cues that drive distinct cellular phenotypes and function. Microenvironments with defined properties, such as mechanical properties and fibril alignment, can elicit specific cellular responses that emulate those observed in vivo. Collagen- and glycosaminoglycan (GAG)-based tissue matrices have been popularized due to their biological ubiquity in a broad range of tissues and the ability to tune structure and mechanical properties through a variety of processes. Here, we investigate the combined effects of static magnetic fields, and GAG and cell encapsulation, on the structure (e.g. collagen fibril orientation) and material properties of collagen matrices. We found that magnetic fields align the collagen-GAG matrix, alter equilibrium mechanical properties and provide a method for encapsulating cells within a three-dimensional aligned matrix. Cells are encapsulated prior to polymerization, allowing for controlled cell density and eliminating the need for cell seeding. Increased relative GAG concentrations reduced the ability to magnetically align collagen fibrils, in part through a mechanism involving increased viscosity and polymerization time of the collagen-GAG solution. This work provides a functional design space for the development of pure collagen and hybrid collagen-GAG matrices in the presence of magnetic fields. Additionally, this work shows that magnetic fields are effective for the fabrication of collagen constructs with controlled fibril orientation, and can be coupled with GAG incorporation to modulate mechanical properties and the response of embedded cells.
The inhibitory action of various steroids on the Hooker-Forbes assay for progesterone.

THE effects that one hormone may have upon the physiological action of another is of considerable interest and importance. Both “synergistic” and “antagonistic” interactions have been observed, and some of these have been discussed recently at some length by Courrier (1951). The possibility that the effect produced by one steroid hormone may be augmented or inhibited by another is of particular significance in procedures for quantitative assays. Hooker and Forbes (1947, 1949) described a microbioassay for progesterone which they considered specific. They found that the accuracy of the assay was unaffected by the presence of estrogen (Hooker and Forbes, 1947). Inasmuch as the response observed by Hooker and Forbes involved changes in the connective tissue of the endometrium of the mouse uterus, this independent action of progesterone seemed to be in conflict with the observations by Morel (1948) on the antagonistic action of estrogen on the decidual reaction in castrated mice.
Adipocyte-Derived Th2 Cytokines and Myeloid PPARδ Regulate Macrophage Polarization and Insulin Sensitivity

Summary The polarization of adipose tissue-resident macrophages toward the alternatively activated, anti-inflammatory M2 phenotype is believed to improve insulin sensitivity. However, the mechanisms controlling tissue macrophage activation remain unclear. Here we show that adipocytes are a source of Th2 cytokines, including IL-13 and to a lesser extent IL-4, which induce macrophage PPARδ/β ( Ppard / b ) expression through a STAT6 binding site on its promoter to activate alternative activation. Coculture studies indicate that Ppard ablation renders macrophages incapable of transition to the M2 phenotype, which in turns causes inflammation and metabolic derangement in adipocytes. Remarkably, a similar regulatory mechanism by hepatocyte-derived Th2 cytokines and macrophage PPARδ is found to control hepatic lipid metabolism. The physiological relevance of this paracrine pathway is demonstrated in myeloid-specific PPARδ −/− mice, which develop insulin resistance and show increased adipocyte lipolysis and severe hepatosteatosis. These findings provide a molecular basis to modulate tissue-resident macrophage activation and insulin sensitivity.
Large elastic, plastic, and creep deflections of curved beams and axisymmetric shells

A numerical method is presented for analyzing large deflections of curved beams and large axisymmetric deflections of shells of revolution. The governing equations that are in finitedifference form are solved by a Newton-Raphson iteration procedure. The plastic stress-strain relations are determined by assuming three independent slip planes that are the planes of maximum shear stresses. The stress-strain relation along each slip plane is assumed to be linearly strain hardening. This plasticity model gives piecewise linear plasticity relations with determinate coefficients. For snap buckling problems, the so-called upper critical load is determined by introducing an artificial spring opposite to the applied load. The true load is then the difference between the applied load and the reaction of the spring. The important mathematical consequence of introducing the spring is to yield a single valued load-deflection curve, thus allowing the critical loads to be determined. The method is applied to several problems including low arches, circular rings, shallow and deep spherical shells under elastic-plastic deformations, and a shallow arch under creep deformation.
One size does not fit all: Managing IT employees' employment arrangements

As alternative employment arrangements proliferate within the information technology (IT) function, it becomes increasingly important to understand the impact of these arrangements on IT employees. A prevalent notion in the IT literature is that these employees are homogeneous in their work values and that they prefer similar employment arrangements. Given the inefficiency of designing individual employment programs, we advocate a middle ground between the two extremes of individualized employment arrangements and “one size fits all.” We conducted two studies. The first study developed an individual's work values profile as a psychological construct. It used a national sample of IT employees to validate a simple, heuristic procedure that was successful in classifying about 80% of the sample into three work values profiles.The second study demonstrated the use of work values profiles for understanding how employment arrangements differentially influence employee satisfaction. It applied the validated procedure to a single organization in order to demonstrate the general applicability of the procedure and to show that it provides researchers and HR professionals with better insights than the assumption that all IT employees are alike. © 2007 Wiley Periodicals, Inc.
Characterization of thermal diffusion of copolymers in solution by thermal field-flow fractionation

Extending our earlier measurements of homopolymer thermal diffusion, we characterize here the thermal diffusion of nine copolymers in toluene by thermal field-flow fractionation (thermal FFF). The copolymers are organized into groups whose members differ in one major aspect only. These differences include monomer ratios in random copolymers, block arrangements in block copolymer pairs having both linear and star-shaped configurations, and arm numbers and arm molecular weights in star-shaped copolymers. By examining the influence (or lack thereof) of these distinctive features on the thermal diffusion coefficient DT, the general phenomenon of thermal diffusion in polymer solutions is further characterized. Specifically, two principal observations are made. First, for copolymers subject to the radial segregation of its monomers, thermal diffusion appears to be dominated by the monomers preferentially located in the outer (free-draining) region of the solvated polymer molecule. Second, for copolymers lacking monomer segregation, DT can be described by a weighted average of the DT values of the corresponding homopolymers, where the weighting factors are the mole-fractions of each monomer type in the copolymer.
Screening for multiple phosphodiesterase type 5 inhibitor drugs in dietary supplement materials by flow injection mass spectrometry and their quantification by liquid chromatography tandem mass spectrometry

A flow injection tandem mass spectrometry method (FI-MS/MS) has been developed to detect enzyme phosphodiesterase type 5 inhibitors, including tadalafil, sildenafil, and vardenafil. Multiple reaction monitoring (MRM) was used to detect the drugs and product ion ratios were used for identification. FI-MS/MS was used for semi-quantification and liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for further confirmation and quantification. One of 13 samples has been found to be adulterated with prescription levels of tadalafil and also low level of sildenafil. The method can be used for screening large numbers of herbal products for adulteration since it takes less than 1 min without chromatographic separation on a column.
Bifurcating periodic solutions for a class of age-structured predator-prey systems

A system of mixed integrodifferential and partial differential equations for an agestructured predator-prey system is studied here. The predator eats all ages of prey, but more of the very young and very old than of the intermediate ages. The existence of periodic solutions corresponding to stable coexistence is proved for a suitable range of parameters by bifurcation theory.