cssi/SciSciGPT-SciSciNet huggingface dataset:
A Ritz Approximation to the Deformation of Anisotropic Slender Structures with Finite-Size Cross Sections

A one-dimensional theory of slender structures with heterogeneous anisotropic materials is presented. It expands Cosserat’s description of beam kinematics by allowing deformation of the beam cross sections. For that purpose, a Ritz approximation is introduced on the cross-sectional warping field, which defines additional elastic degrees of freedom (finitesection modes) in the 1-D model. This results in an extended set of beam dynamic equations that includes direct measures of both the large global displacement and rotations of a certain reference line, and the small local deformations of the cross sections. Two situations of interest are then studied in which this approach provides a simpler alternative to nonlinear shell models: First, we look at the detailed structural response of thin-walled composite beams with distributed loads. In particular, the case of a composite construction with embedded piezoelectric actuators is considered. Second, this methodology is applied to study the low-frequency response characterization of a thin-walled composite beam. Numerical results are presented in both cases, in which a reduced set of finite-section modes allows a full characterization of the actual 3-D structure within a strictly 1-D framework solution.
Ultra-high-Q micro-cavity on a silicon chip

Optical resonators with quality factor as high as 750 million are demonstrated. These silicon-chip-based devices are fabricated without silica reflow, thereby expanding the range of integration opportunities and possible applications.
Rotational diffusion of some polydisperse clay mineral sols

Abstract Flow birefringence studies at low shear (generally, less than 20 sec.1) of polydisperse aqueous suspensions of the clay minerals hectorite, montmorillonite, and attapulgite gave gradient and concentration dependent rotational diffusion constants for such systems. The shear dependent constants could be extrapolated linearly to yield concentration dependent zero-gradient constants; these could then be extrapolated (linearly, if the inverse of the constant is plotted as a function of concentration) to infinite dilution. The resulting zero-concentration constants (θG=0,c=0) were compared with corresponding theoretical values calculated from the particle size distribution (determined by direct counting from electron micrographs) by means of the following equation due to Joly, φ G=0,φ=0 = ∑ i q φ i θ i ∑ i q φ i θ i 2 , where φi is the volume fraction and θi the rotational diffusion constant of the ith component of a polydisperse system containing q noninteracting components. There is good agreement between these calculated constants and those obtained by the linear extrapolation. At a very low gradient (dependent on the particular clay and concentration) an unusual effect was noted; i.e., the rotational diffusion constant increased sharply with decreasing shear.
Where the Boys Are: Understanding online learning and gender

This opinion piece explores the nature of the learners in elearning environments with a special focus on gender. Unexpectedly, more girls than boys are enrolling in all levels of online learning and the implications for elearning professionals are explored here.
Using conceptual blending to describe how students use mathematical integrals in physics

the ways in which students combined their knowledge from calculus and physics to set up integrals. We found that many students were not able to blend their mathematics and physics knowledge in a productive way though they have the required mathematics knowledge. We discussed the productive and unproductive blends that students created when setting up integrals. The results of the study also suggested possible strategies to shifting students’ constructing of blends to more powerful ones.
Experiences with a parallel algorithm for data flow analysis

We have designed a family of parallel data flow analysis algorithms for execution on distributed-memory MIMD machines, based on general-purpose, hybrid algorithms for data flow analysis [Marlowe and Ryder 1990]. We exploit a natural partitioning of the hybrid algorithms and explore a static mapping, dynamic scheduling strategy. Alternative mapping-scheduling choices and refinements of the flow graph condensation used are discussed. Our parallel hybrid algorithm family is illustrated on Reaching Definitions, although parallel algorithms also exist for many interprocedural (e.g., Aliasing) and intraprocedural (e.g., Available Expressions) problems [Marlowe 1989]. We have implemented the parallel hybrid algorithm for Reaching Definitions on an Intel iPSC/2. Our empirical results suggest the practicality of parallel hybrid algorithms.
A trace theorem for solutions of linear partial differential equations

Abstract : This paper proves a trace regularity theorem for the solutions of general linear partial differential equations with smooth coefficients. Our result shows that by imposing additional microlocal smoothness along certain directions. the trace of the solution on a codimension one hypersurface will be just as regular as the solution itself. The proof is based on the Hoermander-Nirenberg pseudo-differential cut-off technique and a "fattening" lemma, together with standard energy estimates.
Content-based image retrieval in picture archiving and communications systems

We propose the concept of content-based image retrieval (CBIR) and demonstrate its potential use in picture archival and communication system (PACS). We address the importance of image retrieval in PACS and highlight the drawbacks existing in traditional textual-based retrieval. We use a digital mammogram database as our testing data to illustrate the idea of CBIR, where retrieval is carried out based on object shape, size, and brightness histogram. With a user-supplied query image, the system can find images with similar characteristics from the archive, and return them along with the corresponding ancillary data, which may provide a valuable reference for radiologists in a new case study. Furthermore, CBIR can perform like a consultant in emergencies when radiologists are not available. We also show that content-based retrieval is a more natural approach to man-machine communication.
Coordination and mechanism of reversible cleavage of S-adenosylmethionine by the [4Fe-4S] center in lysine 2,3-aminomutase.

Lysine 2,3-aminomutase (LAM) catalyzes the interconversion of l-lysine and l-β-lysine, by a radical mechanism initiated by the reversible, reductive homolytic scission of the C5‘−S bond in S-adenosylmethionine (SAM) to form methionine and the 5‘-deoxyadenosyl radical at the active site. LAM is a member of a superfamily of enzymes in which a [4Fe-4S]+ cluster with a unique, noncysteinyl coordinated Fe provides the electron required in the cleavage of SAM. Little is known of the mechanism by which the electron is inserted into SAM, and it is not known whether all enzymes of the family employ the same mechanism. Selenium X-ray absorption spectroscopy (XAS) in the reaction of Se-adenosyl-l-selenomethionine (SeSAM) in place of SAM shows that electron transfer occurs by an inner sphere mechanism culminating in direct ligation of selenomethionine to iron upon cleavage of SeSAM. Here, we report an electron nuclear double resonance (ENDOR) spectroscopic investigation of LAM to which has been bound 14N, 17O, 2H, or...
Effect of Cu deficiency on the optical properties and electronic structure of CuIn1−xGaxSe2

Abstract Spectroscopic ellipsometry measurements of CuInSe 2 (CIS) and CuIn 1− x Ga x Se 2 (CIGS) over a range of Cu compositions reveal that there are important differences in electronic and optical properties between α -phase CIS/CIGS and Cu-poor CIS/CIGS. We find a reduction in the imaginary part of the dielectric function ϵ 2 in the spectral region, 1–3 eV. This reduction can be explained in terms of the Cu-3 d density of states. An increase in band gap is found for Cu-poor CIS and CIGS due to the reduction in repulsive interaction between Cu-3 d and Se-4 p states. We also characterize the dielectric functions of polycrystalline thin-film α -phase CuIn 1− x Ga x Se 2 ( x =0.18 and 0.36) to determine their optical properties and compare them with similar compositions of bulk polycrystalline CuIn 1− x Ga x Se 2 . The experimental results have important implications for understanding the functioning of polycrystalline optoelectronic devices.
Tet-mediated covalent labelling of 5-methylcytosine for its genome-wide detection and sequencing

5-methylcytosine is an epigenetic mark that affects a broad range of biological functions in mammals. The chemically inert methyl group prevents direct labelling for subsequent affinity purification and detection. Therefore, most current approaches for the analysis of 5-methylcytosine still have limitations of being either density-biased, lacking in robustness and consistency, or incapable of analysing 5-methylcytosine specifically. Here we present an approach, TAmC-Seq, which selectively tags 5-methylcytosine with an azide functionality that can be further labelled with a biotin for affinity purification, detection and genome-wide mapping. Using this covalent labelling approach, we demonstrate high sensitivity and specificity for known methylated loci, as well as increased CpG dinucleotide coverage at lower sequencing depth as compared with antibody-based enrichment, providing an improved efficiency in the 5-methylcytosine enrichment and genome-wide profiling.
Fall Meeting Hydrology Highlights

The AGU 1992 Fall Meeting in San Francisco offered the full range of subjects represented by the Hydrology Section's technical committees. The total number of papers was double the number of just 4 years ago. Sessions were well attended. The following highlights were prepared from material written by session organizers. There were 3 full days of papers on snow, ice, and permafrost. One highlight was the special session on new developments in glacier mass-balance studies, which was organized to compare existing methods and examine new techniques for assessing changes in ice mass of the polar ice sheets and alpine glaciers. Current methods for assessing mass change of the ice sheets include satellite laser altimetry to detect surface-elevation changes, surface-based control volume methods to determine net ice flux in a region, and ice-shelf melting and iceberg calving to determine mass loss from the ice sheet. Using these techniques, it is difficult to tell whether the ice sheet is gaining or losing mass. Methods that use drainage basin inputs/outputs indicate a net mass increase, whereas methods that emphasize oceanographic estimates of ice-shelf melting suggest a net mass decrease and estimates based on satellite altimetry are equivocal.
THERMAL, MECHANICAL, AND BIOCOMPATIBILITY PROPERTIES OF CURED MULTI-METHACRYLATES DERIVED FROM PROPOXYLATED, ENZYME OLIGOMERIZED BPA NEAT RESINS

In a previous study, we showed that the methacrylate derivatives of propoxylated bisphenol-A oligomers (EPBPA) have potential application for formulating visible light-curable (VLC) composites for dental restoratives. The purpose of this study was to evaluate the thermal, mechanical and biocompatibility properties of the EPBPA oligomers. The EPBPA oligomer multi-methacrylate: triethylene glycol dimethacrylate (TEGDMA) (50:50/wt:wt) blends were combined with 0.5 wt% camphorquinone (CQ) and 1.0 wt% N,N-di-methyl-aminoethyl methacrylate (DMAEMA). The control was 2,2-bis[4-(2-hydroxy-3-methacryloyloxpoxy) phenyl] propane (BisGMA:TEGDMA) (50:50/wt:wt) blends having the same levels of CQ/DMAEMA. The glass transition temperature (Tg) and the thermal expansion coefficient (α) were obtained for all materials studies, using a thermomechanical analyzer (TMA, TA Instruments 2940 with an expansion probe (heating rate 10°C/min, N2). The compressive (CS) and diametral tensile strength (DTS) tests were carried out using ...
Isolated cleft mitral valve: a variety of congenital mitral regurgitation identified by 2-dimensional echocardiography

Nine children with isolated cleft mitral valve, aged 1 day to 12 years, were studied. The electrocardiogram showed a normal QRS axis in 5 subjects. Cardiac catheterization was performed in 4 patients and demonstrated severe mitral insufficiency in 3 but failed to clearly demonstrate a cleft mitral valve or gooseneck deformity. The mitral cleft was confirmed at operation in 2 patients. Two-dimensional echocardiography demonstrated a cleft dividing the anterior mitral leaflet into 2 portions in each patient. The mitral anulus was normally positioned and the atrioventricular septum present. Atrial and ventricular septa were intact. Features similar to anatomic studies such as accessory chordae and thickening of the edges of the cleft with increasing age were also seen. Two-dimensional echocardiography is the only method available to reliably diagnose isolated cleft of the mitral valve.
Pasture Assessment In The Northeast United States

Many livestock producers have intensified management of pastures in the Northeast and need assessment and monitoring tools to determine how management has influenced pastures. The Pasture Condition Score (PCS) system, developed by the NRCS, was used to assess 108 pastures on 31 farms across the Northeast. We examined the applicability of the system to identify potential problems with its uses and obtain a snapshot of pastureland status. None of the pastures evaluated scored in the lowest category (PCS 45). More than 40% of the pastures scored in the category where only minor changes to management were needed (PCS = 36 to 45) and another 44% fell into the category where some improvements were needed (PCS = 26 to 35). About 15% of pastures scored 16 to 25, indicating immediate management changes were needed. The indicator "percent legume" scored lowest of all the indicators. The low rating for legume content suggests that producers should focus management on establishing and maintaining legumes, which contribute valuable N and high quality forage to the pasture system. Pasture condition score was negatively related to plant species richness. Pastures with the highest species richness generally had many weedy species. This indicates that focusing on increasing the number of species in a pasture without regard to the species composition may not be wise. The PCS system was readily implemented on most pastures. Producers would benefit by observing individual pasture condition indicators at regular intervals to track trends and inform management decisions.
Measurement of the neutrino component of an anti-neutrino beam using a non-magnetized detector

A measurement of the neutrino flux component of the anti-neutrino mode beam observed by the MiniBooNE detector is presented. We find the predicted νμ flux in the anti-neutrino beam should be scaled by 0.65±0.23 (statistical and systematic error included) over all reconstructed energies.
Desalination plant control with microprocessor based digital technology

Abstract The success of improved control strategies for minimizing corrosion and for improving plant operation efficiency is dependent on the data acquired from the process. To obtain improvements in control, more data than is now generally available will have to be collected. Distributed microprocessor based digital technology with a hierarchical system approach provides effective tools for on-line corrosion control by making use of the available historization, trending and alarming features. The hierarchical system structure facilitates improved production efficiency at different levels of sophistication, from a basic control concept to an automatically optimized operation by making use of thermodynamical steam and water properties. A high level of reliability is reached through this system structure, making costly solutions with redundant computers unnecessary.
Do Immigrant Groups Differ in Welfare Usage? Evidence from the U.S.

The study of welfare participation in the United States prior to the 1996 Welfare Reform Act and afterward has primarily focused on comparing native and immigrant households. Analyses that have gone beyond this broad classification have focused on comparisons across race, with particular focus on Hispanic immigrants. This paper moves away from the existing literature by investigating whether there is a difference in welfare usage among immigrant based on their birthplace. Using a probit model, we investigate this potential difference by testing two related hypotheses. Our results suggest that the probability of welfare usage for immigrants with similar characteristic, differ for some immigrant groups. We also find that for some immigrant groups, citizen and noncitizens differ with respect to welfare usage.
Acetylcholine receptor: channel-opening kinetics evaluated by rapid chemical kinetic and single-channel current measurements

A combination of rapid chemical kinetic (quench-flow) and single-channel current measurements was used to evaluate kinetic parameters governing the opening of acetylcholine-receptor channels in the electric organ (electroplax) of Electrophorus electricus. Chemical kinetic measurements made on membrane vesicles, prepared from the E. electricus electroplax, using carbamoylcholine (200 microM-20 mM) at 12 degrees C, pH 7.0, and in the absence of a transmembrane voltage, yielded values for K1 (dissociation constant for receptor activation), phi (channel closing equilibrium constant), J (specific reaction rate for ion flux), and alpha max (maximum inactivation rate constant) of 1 mM, 3.4, 4 x 10(7) M-1 s-1, and 12 s-1, respectively. The single-channel current recordings were made with cells also from the E. electricus electroplax, at the same temperature and pH as the chemical kinetic measurements, using carbamoylcholine (50 microM-2 mM), acetylcholine (500 nM), or suberyldicholine (20 nM). Single-channel current measurements indicated the presence of a single, unique open-channel state of the E. electricus receptor, in concurrence with previous, less extensive measurements. The rate constant for channel closing (kc) obtained from the mean open time of the receptor channel is 1,100 s-1 for carbamoylcholine, 1,200 s-1 for acetylcholine, and 360 s-1 for suberyldicholine at zero membrane potential; and it decreases e-fold for an 80 mV decrease in transmembrane voltage in each case. The decrease in mean open times of the receptor channel that is associated with increasing the carbamoylcholine concentration is interpreted to be due to carbamoylcholine binding to the regulatory (inhibitory) site on the receptor. An analysis of data obtained with carbamoylcholine showed that the closed times within a burst of channel activity fit a two-exponential distribution, with a concentration-independent time constant considered to be the time constant for carbamoylcholine to dissociate from the regulatory site, and a carbamoylcholine concentration-dependent, but voltage-independent, time constant interpreted to represent the rate constant for channel opening (k0). An analysis of the mean closed time data on the basis of the minimum model gives values for K1 and k0 of 0.6 mM and 440 s-1, respectively, with carbamoylcholine as the activating ligand. The values obtained for K1, phi (= kc/k0), J, and alpha from the single-channel current measurements using electroplax are in good agreement with the values obtained from the chemical kinetic measurements using receptor-rich vesicles prepared from the same cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Linear and nonlinear interactions of surface waves with bodies by a three-dimensional Rankine panel method

Linear and second-order surface wave interactions with floating and bottom-mounted bodies of realistic geometry are simulated in the time domain by a three-dimensional Rankine panel method. The fundamental stability analysis governing the propagation of transient wave disturbances on a panel mesh distributed on the free surface is carried out from first principles. The radiation condition is enforced by a dissipative beach selected to coincide with an outer annulus of panels. The fundamental physics governing the wave energy absorption is presented and the beach attributes are selected and validated for the linear and second-order problems. Computations are presented of the linear and sum-frequency second-order forces on a single and multiple truncated circular cylinders, and very good agreement is found with benchmark computations. The accuracy and efficiency of this method render it a promising candidate for the study of complex nonlinear wave induced phenomena upon offshore platforms, like springing and ringing.
The recognition and significance of Arcanobacterium haemolyticum

Abstract Animal studies have shown that A. haemolyticum , by itself, has pathogenic potential. In humans the organism is associated with pharyngitis and skin ulcers and is often coisolated with other pathogens, particularly S. pyogenes . Present studies are not definitive, because the baseline isolation rates from different sites from healthy people have not been established and a search for other simultaneous causes of disease, such as viruses, mycobacteria, or anaerobes, has not been completed (30, 36, 37). Maximum detection of A. haemolyticum from patients with pharyngitis can be achieved if human blood agar plates are used instead of SBA for throat cultures and if the plates are incubated for 48 h. The organism could be detected more often at extrapharyngeal sites if it were realized that coryneforms, when recovered in significant numbers, should be identified minimally to the exclusion of A. haemolyticum .
PXAMS — projectile X-ray AMS: X-ray yields and applications☆

Characteristic X-rays have recently been explored as a method for the detection and identification of ions in accelerator mass spectrometry (AMS) [H. Artigalas et al., Nucl. Instr. and Meth. B 92 (1994) 227; M. Wagner et al., Nucl. Instr. and Meth. B 89 (1994) 266]. After analysis in the AMS spectrometer, the ions stop in an appropriately chosen target and the induced X-rays identify the ions by atomic number. For the application of AMS to higher mass isotopes, characteristic X-rays allow significantly better discrimination of competing atomic isobars than is possible using energy loss detectors. Characteristic X-rays also show promise as a convenient component in hybrid detection systems. Measurements of X-ray yields are presented for Si, Fe, Ni, Se, Mo, and Pd ions of 0.5 – 2 MeV/amu. The yields rise by more than a factor of 10 over this energy range, and approach 1 X-ray per incident ion at 2 MeV/amu for the lighter ions. Preliminary work on the application of PXAMS to the detection of 79Se is described.
The role of the glycosaminoglycan layer in bladder defense mechanisms and interstitial cystitis

The bladder surface glycosaminoglycan layer is an important defense mechanism for the transitional epithelium. It allows adaptation to the constant exposure to urine, and controls the permeability of urinary substances to the transitional cell. This layer seems to be impaired in some patients with interstitial cystitis.
Effect of the xid gene on graft-versus-host-induced autoantibody production in nonautoimmune mice.

Graft-versus-host disease (GVH) was used to induce an autoimmune state in F1 recipients using donor spleen cells, splenic T cells, or Lyt 1+2- splenic T cells from either normal DBA/2 mice or from DBA/2 mice carrying the X-linked immunodeficiency (xid) gene. Recipients were either nondefective (DBA/2 X CBA/N)F1 males or reciprocal cross (CBA/N X DBA/2)F1 male mice carrying the xid gene. GVH induced hypergammaglobulinemia and anti-ssDNA autoantibodies in F1 recipients. Immunodeficient (CBA/N X DBA/2)F1 recipients had less hypergammaglobulinemia and IgG anti-ssDNA than did normal (DBA/2 X CBA/N)F1 recipients. Spleen cells, splenic T cells, and Lyt 1+2- splenic T cells from immunodeficient DBA/2.xid donors were less able to induce GVH and autoimmunity than normal DBA/2 donors. These studies suggest that the xid gene may reduce the autoimmune hyperractive state, but may do so by acting on more than one cell population, including T cells.
Hardening of Commercial CMOS PROMS with Polysilicon Fusible Links

The method by which a commercial 4K CMOS PROM with polysilicon fuses was hardened and the feasibility of applying this method to a 16K PROM are presented. A description of the process and the necessary minor modifications to the original layout are given. The PROM circuit and discrete device characteristics over radiation to 1000K rad-Si are summarized. The dose rate sensitivity of the 4K PROMs is also presented.
Centimeter-long electron transport in marine sediments via conductive minerals

Centimeter-long electron conduction through marine sediments, in which electrons derived from sulfide in anoxic sediments are transported to oxygen in surficial sediments, may have an important influence on sediment geochemistry. Filamentous bacteria have been proposed to mediate the electron transport, but the filament conductivity could not be verified and other mechanisms are possible. Surprisingly, previous investigations have never actually measured the sediment conductivity or its basic physical properties. Here we report direct measurements that demonstrate centimeter-long electron flow through marine sediments, with conductivities sufficient to account for previously estimated electron fluxes. Conductivity was lost for oxidized sediments, which contrasts with the previously described increase in the conductivity of microbial biofilms upon oxidation. Adding pyrite to the sediments significantly enhanced the conductivity. These results suggest that the role of conductive minerals, which are more commonly found in sediments than centimeter-long microbial filaments, need to be considered when modeling marine sediment biogeochemistry.
In-situ single cell electroporation using optoelectronic tweezers

Optoelectronic tweezers are used to achieve light-induced, in-situ electroporation of HeLa cells. By controlling electrical bias, patterned light induces either single cell movement or electroporation. Fluorescent dye and dielectrophoretic response are used to monitor electroporation.
Labor Studies in the South

The Fourth Biennial Southern Labor Studies Conference will meet in Atlanta, September 30-October 2, 1982. The program will include both traditional and working class history, and David Montgomery (Yale University) has agreed to de liver the keynote address. One of the highlights of the Conference will be a twenty year retrospective on the publication of E.P. Thompson's The Making of the Eng lish Working Class. Selected papers of the Second Southern Labor Studies Conference, 1978, were recently released by Greenwood Press. The volume, entitled Southern Work ers and their Unions 1880-1975, and edited by Merl Reed, Leslie Hough, and Gary Fink, includes essays on black workers, civil rights, women, southern coal miners, and a more broadly focused essay by Lorin Lee Cary (University of Toledo) on middle-echelon labor leaders. The Atlanta Labor History Project, under the auspices of the Southern Labor Archives, continues to sponsor public programs on the history of working Atlan tans between the 1880s and the World War II era. Project results are disseminated through articles in the labor press, field trips, public seminars, the development of a labor history tour, and the identification and documentation of significant labor historical sites. Much of the work has been directed by Clifford M. Kuhn (UNC) and has been partially funded through grants from the Georgia Endowment for the Humanities. The Southern Oral History Program at the University of North Carolina, Chapel Hill, under the directorship of Jacquelyn Dowd Hall, continues its investi gation of Piedmont industrialization. Hundreds of interviews have been completed and project workers are now beginning to analyze and interpret the results of their research. For information contact Professor Hall through the Department of His tory, UNC. Mary Frederickson (UNC) and Dale Newman (University of Pittsburgh) re cently conducted a series of public programs reconstructing the history of Georgia textile workers through slide tape media presentations, panel discussions and inter changes with the audience. The programs were held in various textile towns and were targeted toward textile workers and their families.
DEMOIR: a hybrid architecture for expertise modeling and recommender systems

Although employees' expertise has long been regarded as an important asset in organizations at least on a par with capital, goods and documented information, it is only recently that automated systems to enhance the visibility and traceability of employees with particular expertise started to receive research attention. In this paper, we introduce a systematic classification of alternative architectures for a core functionality of expert finding systems, namely expertise modeling. We also analyze the advantages and disadvantages of each approach and present our hybrid solution. We discuss how this solution addresses the requirements of (I) distributed and heterogeneous organizational and personal expertise data sources and, (2) centralized access to extracted expertise information.
Application of AI to real-time intelligent attitude control of spacecraft

Modern spacecraft demand from an attitude control system very high performance and accuracy, and many new features, such as self-modification, adaptability, more autonomy, and fault tolerance. It is noted that artificial intelligence and knowledge-based system techniques can be applied to spacecraft attitude control to meet the demanding requirements and to provide many new features. The author discusses the need for and the benefits of integrating artificial intelligence and automatic control techniques. This approach gives the attitude control system the power of reasoning, judgment, and learning and the capability to cope with unexpected and changing situations. An architecture for a real-time intelligent attitude controller is described, consisting of a traditional low-level controller and a knowledge-based system provides meta control to the low-level controller. >
Roles of Gremlin 1 and Gremlin 2 in regulating ovarian primordial to primary follicle transition.

A network of extracellular signaling factors has previously been shown to act in concert to control the ovarian primordial to primary follicle transition. The current study was designed to investigate the roles of the endogenous bone morphogenetic protein (BMP) inhibitors Gremlin1 (GREM1) and Gremlin2 (GREM2) in primordial follicle transition in the rat ovary. GREM1 and GREM2 treatment were found to reverse the effects of Anti-Mullerian Hormone (AMH) to inhibit follicle transition in a whole ovary culture system. GREM1 reversed the effect of bone morphogenetic protein 4 (BMP4) to stimulate primordial follicle transition. Immunohistochemical studies showed that GREM2, but not GREM1, was present in primordial follicles suggesting GREM2 may regulate primordial follicle transition in vivo. Co-immunoprecipitation studies indicated that GREM2 directly binds to AMH, as well as to BMP4. Transcriptome analyses of ovaries treated with GREM2 or GREM1 yielded negligible numbers of differentially expressed genes, suggesting the immediate effects of GREM2 or GREM1 appear to be at the level of protein-protein interactions, rather than direct actions on the cells. A number of other ovarian growth factors were found to influence the expression of Grem2. Observations suggest that Grem2 is a part of the signaling network of growth factors that regulate the primordial to primary follicle transition. Insights into the regulatory networks affecting the pool of primordial follicles is important to understand the molecular basis for reproductive diseases such as primary ovarian insufficiency (POI).
The Naturally Occurring Mutants of DDB Are Impaired in Stimulating Nuclear Import of the p125 Subunit and E2F1-Activated Transcription

The human UV-damaged-DNA binding protein DDB has been linked to the repair deficiency disease xeroderma pigmentosum group E (XP-E), because a subset of XP-E patients lack the damaged-DNA binding function of DDB. Moreover, the microinjection of purified DDB complements the repair deficiency in XP-E cells lacking DDB. Two naturally occurring XP-E mutations of DDB, 82TO and 2RO, have been characterized. They have single amino acid substitutions (K244E and R273H) within the WD motif of the p48 subunit of DDB, and the mutated proteins lack the damaged-DNA binding activity. In this report, we describe a new function of the p48 subunit of DDB, which reveals additional defects in the function of the XP-E mutants. We show that when the subunits of DDB were expressed individually, p48 localized in the nucleus and p125 localized in the cytoplasm. The coexpression of p125 with p48 resulted in an increased accumulation of p125 in the nucleus, indicating that p48 plays a critical role in the nuclear localization of p125. The mutant forms of p48, 2RO and 82TO, are deficient in stimulating the nuclear accumulation of the p125 subunit of DDB. In addition, the mutant 2RO fails to form a stable complex with the p125 subunit of DDB. Our previous studies indicated that DDB can associate with the transcription factor E2F1 and can function as a transcriptional partner of E2F1. Here we show that the two mutants, while they associate with E2F1 as efficiently as wild-type p48, are severely impaired in stimulating E2F1-activated transcription. This is consistent with our observation that both subunits of DDB are required to stimulate E2F1-activated transcription. The results provide insights into the functions of the subunits of DDB and suggest a possible link between the role of DDB in E2F1-activated transcription and the repair deficiency disease XP-E.
INTERFERENCE BETWEEN THE INFLUENZA VIRUSES : II. THE EFFECT OF VIRUS RENDERED NON-INFECTIVE BY ULTRAVIOLET RADIATION UPON THE MULTIPLICATION OF INFLUENZA VIRUSES IN THE CHICK EMBRYO.

Influenza A or influenza B virus rendered non-infective by ultraviolet radiation was found to be capable of producing interference with the multiplication of active influenza viruses in the chick embryo. Certain temporal and quantitative relationships affecting the interference phenomenon with this host-virus system were studied. An hypothesis of the mechanism of interference between the influenza viruses is proposed and discussed.
Does ventral hernia defect length, width, or area predict postoperative quality of life? Answers from a prospective, international study

Abstract Background The goal of this study was to determine if ventral hernia defect length, width, or area predict postoperative pain and quality of life following ventral hernia repair (VHR). Methods The International Hernia Mesh Registry, a prospective database from 40 institutions worldwide, was queried for patients undergoing VHR from October 2007 to June 2012. Laparoscopic and open VHR were evaluated separately. Width and length were stratified into large, ≥10 cm and small, Results In total, 865 International Hernia Mesh Registry patients underwent VHR. Large defect width, length, and area had no association with hernia recurrence or reoperation in both open and laparoscopic VHR. There was a significant increase in operating room time and length of stay for large compared with small width, length, and area for open and laparoscopic VHR patients (P Conclusions Patients undergoing laparoscopic or open VHR with large defect widths and total area have a greater chance of pain and activity limitation at 1-mo follow-up, but not long term. Large defect lengths are associated with increased early and chronic discomfort in open VHR only.
Using a multipath network for reducing the effects of hot spots

One type of interconnection network for a medium to large-scale parallel processing system (i.e., a system with 2/sup 6/ to 2/sup 16/ processors) is a buffered packet-switched multistage interconnection network (MIN). It has been shown that the performance of these networks is satisfactory for uniform network traffic. More recently, several studies have indicated that the performance of MIN's is degraded significantly when there is hot spot traffic, that is, a large fraction of the messages are routed to one particular destination. A multipath MIN is a MIN with two or more paths between all source and destination pairs. This research investigates how the Extra Stage Cube multipath MIN can reduce the detrimental effects of tree saturation caused by hot spots. Simulation is used to evaluate the performance of the proposed approaches. The objective of this evaluation is to show that, under certain conditions, the performance of the network with the usual routing scheme is severely degraded by the presence of hot spots. With the proposed approaches, although the delay time of hot spot traffic may be increased, the performance of the background traffic, which constitutes the majority of the network traffic, can be significantly improved. >
Surface modification of nano-silica with amides and imides for use in polyester nanocomposites

Surface modified nano-silica was synthesized through a condensation reaction of the silanol groups on the silica surface with 3-aminopropyltrimethoxysilane (APS). This primary amine offers a wide range of derivatization options and acts as a linker between a silica surface and many organic species. Quantitation of the results indicated the presence of 3–4 reactive APS groups per nm2 of silica. This implies that the silanol groups present on the surface of the silica have reacted to a high extent. APS-treated silica was further treated with a series of acid anhydrides to yield more stable amidoalkyl and imidoalkyl silica. The modified surfaces were analysed by thermogravimetric analysis (TGA), Fourier-transform infra-red (FT-IR) and solid-state 13C NMR spectroscopy techniques to study the organic content and functional composition. Results indicate that the silica particles functionalized with imidoalkylsiloxane (IASi) have much higher thermal stabilities compared to aminoalkyl functionalized silica. It was also observed that thermal stability of the IASi does not depend on the acid anhydride used for the derivatization of the APS treated silica. Furthermore we used this IASi for the synthesis of poly(ethylene terephthalate) (PET)–silica nanocomposites. Dynamic mechanical analysis revealed an enhancement of the storage modulus with increasing silica content at ambient temperature as well as above the glass-transition temperature.
Selective loss of imprinting in the placenta following preimplantation development in culture.

Preimplantation development is a period of dynamic epigenetic change that begins with remodeling of egg and sperm genomes, and ends with implantation. During this time, parental-specific imprinting marks are maintained to direct appropriate imprinted gene expression. We previously demonstrated that H19 imprinting could be lost during preimplantation development under certain culture conditions. To define the lability of genomic imprints during this dynamic period and to determine whether loss of imprinting continues at later stages of development, imprinted gene expression and methylation were examined after in vitro preimplantation culture. Following culture in Whitten's medium, the normally silent paternal H19 allele was aberrantly expressed and undermethylated. However, only a subset of individual cultured blastocysts (∼65%) exhibited biallelic expression, while others maintained imprinted H19 expression. Loss of H19 imprinting persisted in mid-gestation conceptuses. Placental tissues displayed activation of the normally silent allele for H19, Ascl2, Snrpn, Peg3 and Xist while in the embryo proper imprinted expression for the most part was preserved. Loss of imprinted expression was associated with a decrease in methylation at the H19 and Snrpn imprinting control regions. These results indicate that tissues of trophectoderm origin are unable to restore genomic imprints and suggest that mechanisms that safeguard imprinting might be more robust in the embryo than in the placenta.
Compiler-Directed Code Restructuring for Operating with Compressed Arrays

Memory system utilization is an important issue for many embedded systems that operate under tight memory limitations. This is a strong motivation for recent research on reducing the number of banks required during execution of a given application. Reducing memory space requirements of an application can bring three potential benefits. First, if we are to design a customized memory system for a given embedded application, reducing its memory requirements can cut the overall cost. Second, if we are to execute our application in a multi-programmed environment, the saved memory space can be used by other applications, thereby increasing the degree of multiprogramming. Third, it is also possible to reduce the energy consumption in a banked memory system by reducing the amount of memory space occupied by application data and placing the unused banks into low-power operating modes. This paper proposes a novel memory saving strategy for array-dominated embedded applications. The idea is to exploit the value locality in array data (e.g., those from the multi-media domain) by storing arrays in a compressed form to save memory space. Based on the compressed forms of the input arrays, our compiler-based approach automatically determines the compressed forms of the intermediate and output arrays and also automatically restructures the application code so that we can also reduce execution time (by exploiting value locality). Our experimental results show that this scheme is very effective in practice and reduces the memory space requirements of the applications tested by 19% on average. The experimental results also show that the proposed approach reduces the execution cycles of the original codes by 14% on average
Risk and protective factors for methamphetamine use and nonmedical use of prescription stimulants among young adults aged 18 to 25.

This article reports on correlates of past-year nonmedical use of prescription stimulants and methamphetamine among young adults aged 18 to 25. Data from the 2002 National Survey on Drug Use and Health (NSDUH) were used to conduct logistic regression analyses of the demographic, psychosocial, and behavioral correlates of nonmedical stimulant use. The sample size was 23,645. Multivariate analyses revealed that selling drugs and using marijuana and other illegal drugs were associated with increased odds of both methampethamine and nonmedical prescription stimulant use. Females, individuals not enrolled in college, and those who had been arrested were more likely than their counterparts to have used methamphetamine, whereas black individuals and less religious individuals were less likely than their counterparts to have used methamphetamine. Psychological distress, sensation seeking, binge drinking, and college enrollment were associated with increased risks of nonmedical prescription stimulant use, whereas Hispanic and other ethnic identification were associated with decreased risks of nonmedical prescription stimulant use. Different intervention strategies are needed to prevent methamphetamine use versus nonmedical prescription stimulant use.
Fully monolithic 18.7GHz 16Ps GaAs mode-locked oscillators

We report a mode-locked electrical oscillator fully integrated in GaAs. It self generates a periodic train of pulses with a 16-ps pulse width and a 18.7-GHz frequency. This is the fastest electrical mode-locked oscillator to date, and the first integration of reflective mode-locked electrical oscillator. It works by sending a pulse back and forth on a coplanar waveguide with reflections at both ends. The reflection occurs with level-dependent gain that enables pulse formation and stabilization.
Antifungal drug resistance of pathogenic fungi

Pathogenic fungi have many complex mechanisms of resistance to antifungal drugs. Information about the clinical, cellular, and molecular factors contributing to antifungal-drug resistance continues to accumulate. We critically review the diagnosis, epidemiology, and mechanisms of antifungal drug resistance of pathogenic fungi. Better understanding of this resistance should assist in developing better detection strategies for preventing and treating refractory mycoses in the future.
Discovery of a metagenome-derived enzyme that produces branched-chain acyl-(acyl-carrier-protein)s from branched-chain α-keto acids.

Clones that confer the production of N-acyl amino acids to model cultured bacterial hosts are frequently identified in activity-based screens of soil DNA libraries. The N-acyl amino acids encoded by these clones are synthesized from acyl-(acyl-carrier-protein)s (acyl-ACPs, ACP) and amino acids using a diverse group of bacterial enzymes referred to as N-acyl amino acid synthases (NASs).[1, 2] The acyl-ACP substrates of NAS enzymes are common intermediates in the de novo synthesis of fatty acids by the type II fatty acid synthase system (FAS II).[3] In addition to N-acyl amino acids, FAS II-derived acyl-ACPs also serve as acyl-donors in the production of N-acyl homoserine lactone autoinducers, the cofactor lipoic acid and several lipopeptide antibiotics (Figure 1A, compounds 1–4).[4–9] During a recent screen of soil metagenomic libraries for clones exhibiting antimicrobial activity, we uncovered an NAS-containing clone (clone EC5) that confers the production of long-chain N-acyl-phenylalanines and N-acyl-tryptophans to multiple Gram-negative host species.[10] The NAS-encoding gene found on clone EC5, nasA, is the first gene in a predicted two gene operon, nasAB (GenBank Accession No. {"type":"entrez-nucleotide","attrs":{"text":"GQ869383","term_id":"260177223","term_text":"GQ869383"}}GQ869383). The second gene in this operon, nasB, encodes for a putative 1118 residue protein that contains six well-characterized Pfam homology domains (Figure 1B).[11] Based on generic functional predictions for these domains, we hypothesized that this enzyme was likely to be involved in the formation of ACP-linked fatty acids similar to those produced by bacterial FAS II systems. Here we report results from a series of heterologous expression experiments in Burkholderia graminis C4D1M, which show that nasB functions to provide branched-chain acyl-ACPs for nasA. Many bacteria, particularly Gram-negative species, do not natively produce branched-chain fatty acids.[3] NasB and its homologs are likely used by bacteria with straight-chain specific FAS II systems for generating branched-chain acyl-ACP substrates and should be useful as tools for synthesizing these substrates in model heterologous expression systems in which they are not natively produced (e.g. E. coli).
The survival of bacteria in dust: II. The effect of atmospheric humidity on the survival of bacteria in dust

Dust from scarlet-fever wards was exposed to a controlled range of atmospheric humidities by enclosure in metal boxes containing anhydrous calcium chloride and saturated solutions of potassium carbonate, sodium nitrite, potassium bromide and sodium sulphate. The death-rate of total organisms, Staphylococcus aureus and Streptococcus pyogenes in the dust was assessed by periodic sampling of series of twenty 10mg. portions. A positive correlation between atmospheric humidity and death-rate was observed for the three groups of organisms counted in three specimens of dust.