cssi/SciSciGPT-SciSciNet huggingface dataset:
STRUCTURE OF A HYPOTHALAMIC PEPTIDE POSSESSING GONADOTROPIN-RELEASING ACTIVITY

A second batch of porcine gonadotropin-releasing hormone, isolated by a new procedure, gave an amino acid composition: Trp 1, His 1, Arg 1, Ser 1, Glu 1, Pro 1, Gly 2, Leu 1, and Tyr 1, with 67% amino acid recovery. Edman-dansyl degradation of the intact hormone did not give a positive result, suggesting a blocked N-terminus. Esterification of the peptide with [14C]diazomethane failed to yield any [14C]methylester, indicating the absence of any free carboxyl-group in the molecule. This suggested that the C-terminus of the hormone is also blocked. High and low resolution mass spectral fragmentation of the hormonal peptide gave intense bands due to (pyro)-glutamyl residue which occupies the N-terminus. The main diketopiperazine bands from the mass spectral data were due to (pyro)Glu-His, Trp-Ser, Tyr-Gly, Leu-Arg, Arg-Pro, Pro-Gly, and their decomposition. Mass spectral fragmentation of the hormone and its chymotryptic fragments after acetylation and permethylation, before and after methanolysis, yielded orderly patterns, indicating the sequence of the deca-peptide and also confirming the (pyro)glutamyl N-terminus and the glycylamide C-terminus. These studies, in agreement with the conventional chemical sequencing of the hypothalamic peptide after enzymic cleavage, proved that the structure of the hormone is: Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2
Conditions Requiring Emergency Ophthalmologic Consultation

Emergency physicians are well prepared to diagnose and manage the majority of visits requiring emergency ophthalmology consultation. However, deciding which cases require the expertise of an ophthalmologist and in what time frame can be a challenge. This article attempts to provide guidelines to the emergency physician regarding when to call for emergency ophthalmology consultation.
An empirical analysis of debugging performance — differences between iterative and recursive constructs

Abstract An experiment involving more than 500 responses from over 250 subjects was conducted for the purpose of identifying differences in debugging performance among subjects who debugged iterative code and those who debugged recursive code. The subjects, classified as novices or experienced, based on programming experience, were asked to locate and fix a single logical bug in small segments of C code. Two different tasks – searching a linked list and copying a linked list, were used in the experiment. Statistical analyses yielded the following significant results: (i) 63.2% of all subjects located the bug in the recursive constructs compared to 41.5% for the iterative constructs (p
Polyampholyte terpolymers of amphoteric, amino acid‐based monomers with acrylamide and (3‐acrylamidopropyl)trimethyl ammonium chloride

Low-charge-density amphoteric copolymers and terpolymers composed of acrylamide, (3-acrylamidopropyl)trimethyl ammonium chloride, and the amino acid derived monomers (e.g., N-acryloyl valine, N-acryloyl alanine, and N-acryloyl aspartate) were prepared via free-radical polymerization in aqueous media to yield terpolymers with random charge distributions and homogeneous compositions. Sodium formate (NaOOCH) was employed as a chain transfer agent during the polymerization to suppress gel effects and broadening of the molecular weight distribution. Terpolymer compositions were determined by 13 C and 1 H NMR spectroscopy. Terpolymer molecular weights and polydispersity indices were obtained via size exclusion chromatography/multi-angle laser light scattering, and hydrodynamic diameter values were obtained via dynamic light scattering. The solution properties of low-charge-density amphoteric copolymers and terpolymers have been studied as a function of solution pH, ionic strength, and polymer concentration. The low-charge-density terpolymers display excellent solubility in deionized (DI) water with no phase separation. The charge-balanced terpolymers exhibit antipolyelectrolyte behavior at pH values ≥(6.5 ± 0.2). As solution pH is decreased, these charge-balanced terpolymers become increasingly cationic because of the protonation of the anionic repeat units. Charge-imbalanced terpolymers generally demonstrate polyelectrolyte behavior, although the effects of intramolecular electrostatic interactions (e.g., polyampholyte effects) on the hydrodynamic volume are evident at certain values of solution pH and salt concentration. The aqueous solution behavior (i.e., globule-to-coil transition at the isoelectric point in the presence of salt and globule elongation with increasing charge asymmetry) of the terpolymers in the dilute regime correlates well with that predicted by the polyampholyte solution theories of Dobrynin and Rubinstein as well as Kantor and Kardar. Examination of comonomer charge density, hydrogen-bonding ability, and spacer group (e.g., the moiety separating the ionic group from the polymer chain) indicates that conformational restrictions of the amino acid comonomers result in increased chain stiffness and higher solution viscosities in DI water and brine solutions.
Good News for the Logical Autonomy of Ethics

Toomas Karmo claims that his taxonomy of ethical sentences has the result that there does not exist a sound argument with all non-ethical premises and an ethical conclusion. In a recent paper, Mark T. Nelson argues against this claim. Nelson presents a sound argument that he takes to be such that (i) Karmo’s taxonomy classifies that argument’s single premise as non-ethical and (ii) Karmo’s taxonomy classifies that argument’s conclusion as ethical. I attempt to show that Nelson is mistaken about (ii). For any possible world at which the premise of Nelson’s argument is true, Karmo’s taxonomy classifies the conclusion of Nelson’s argument as non-ethical.
The relationship between the open-circuit potential of a galena electrode and the dissolved lead concentration

Abstract Electrochemical experiments and thermodynamic mass balance calculations have been conducted to determine the relationship between the open-circuit potential of a galena electrode and the dissolved lead concentration at pH = 0, 1.1 and 4.6. The experiments have been performed in such a way that the potential covers the range from reducing values where Pb 0 is present on the electrode surface to oxidizing ones where the anodic dissolution of PbS takes place. The results indicate that the response of this system is characterized by a region at low potentials where the electrode behaves essentially as a Pb 0 electrode and another at higher potentials where the electrode has reverted to its original PbS character. The transition between these two regions is sharp and occurs when all (pH=0 and 1.1) or most (pH=4.6) of the Pb 0 has dissolved from the surface. The pH has also been found to have a significant effect on the reversibility of the system. At pH=0, the potential obeys Nernstian behavior along both portions of the electrode response. Raising the pH to 1.1 causes the observed potentials along the lower Pb 0 -like segment to deviate anodically from the reversible values. When a pH of 4.6 is reached, the upper segment shows an anodic shift as well.
Observations on spiraling empiricism: its causes, allure, and perils, with particular reference to antibiotic therapy

Spiralicy empiricism describes the inappropriate treatment, or the unjustifiable escalation of treatment, of suspected but un documented infections diseases
Plasma Experiment for Planetary Exploration (PEPE)

The Plasma Experiment for Planetary Exploration (PEPE) is one of the new instrument technologies being demonstrated with the New Millennium Deep Space One mission. PEPE will serve three purposes, (1) the characterization of the environment induced by the Solar Electric Propulsion (SEP) system while validating the feasibility of flying high performance plasma instrumentation on future SEP missions, (2) to carry out state-of-the-art plasma measurements in support of the scientific investigation of an asteroid and comet flyby, and (3) to validate several new plasma sensor technologies needed for future space physics and planetary missions. PEPE’s measurement capabilities approach those of the Cassini Plasma Spectrometer (CAPS) instrument, but with much lower resource requirements, at a lower cost and delivered on a much faster time table. PEPE will provide three dimensional mass-resolved plasma distributions up to 30 keV over 2.8 π ster on a time frame of 64 seconds. PEPE simultaneously measures both ions and electrons and provides energy per charge analysis and time-of-flight measurements to yield high resolution mass analysis. Details of the PEPE design are presented as well as an overview of both the technology and scientifically driven measurement objectives. The potential future applications of PEPE technology are also discussed.
Ventricular septal rupture detected by cross‐sectional echocardiography

Cross-sectional echocardiography was used to directly visualize abnormal wall motion and detect the site of ventricular septal rupture in a patient with acute inferior myocardial infarction. The presence of the defect was confirmed by injecting indocyanine green into the left ventricle at the time of cardiac catheterization. Cross-sectional echocardiography provides a rapid, atraumatic means for evaluating patients with complicated acute myocardial infarction.
Core promoter involvement in the induction of rat ornithine decarboxylase by phorbol esters.

Overexpression of ornithine decarboxylase (ODC) is an important oncogenic event in tumorigenesis. Although ODC was one of the first genes described whose product is inducible by 12-O-tetradecanoylphorbol-13-acetate (TPA), the mechanisms of ODC transcriptional regulation have remained elusive. In this study, we systematically analyzed the rat ODC core promoter region for novel TPA response elements. Analysis of linker scanning mutants of the ODC promoter from the TATA box to the transcription start site demonstrated that mutation of the TATA box reduced the TPA induction ratio by 40%, while the basal ODC promoter activity was not significantly changed. A novel region between nt - 20 to - 10 was shown to be critical for both basal promoter activity and induction by TPA. Random mutagenesis of this region showed that conversion of the GC-rich wild-type sequence into a T-rich sequence could either substantially increase the basal promoter activity and decrease the TPA induction ratio or dramatically reduce the basal promoter activity, depending on the T content. Mutant R5, containing an ATTT sequence at nt - 15 to - 12, caused a more than twofold increase of basal promoter activity and 80% reduction of TPA induction ratio. We suggest that this region interacts with components of the general transcription machinery and that the strength of this interaction is mediated by the T-content in this region.
Modeling of interface cracks in fiber-reinforced composites with the presence of interphases using the boundary element method

Abstract An advanced boundary element method (BEM) with thin-body capabilities was developed recently for the study of interphases in fiber-reinforced composite materials (Y.J. Liu, N. Xu and J.F. Luo, Modeling of interphases in fiber-reinforced composites under transverse loading using the boundary element method, ASME J. Appl. Mech. 67 (2000) 41–49). In this BEM approach, the interphases are modeled as thin elastic layers based on the elasticity theory, as opposed to spring-like models in the previous BEM and some FEM work. In the present paper, this advanced BEM is extended to study the interface cracks at the interphases in the fiber-reinforced composites. These interface cracks are curved cracks between the fiber and matrix, with the presence of the interphases. Stress intensity factors (SIFs) for these interface cracks are evaluated based on the developed models. The BEM approach is validated first using available analytical and other numerical results for curved cracks in a single material and straight interface cracks between two materials. Then, the interface cracks at the interphases of fiber-reinforced composites are studied and the effects of the interphases (such as the thickness and materials) on the SIFs are investigated. As a special case, results of the SIFs for sub-interface cracks are also presented. It is shown that the developed BEM is very accurate and efficient for the interface crack analyses, and that the properties of the interphases have significant influences on the SIFs for interface cracks in fiber-reinforced composites.
Regulation of Fcγ R II expression and function by B lymphocyte activators

B lymphocytes cultured with LPS show increased expression of Fc gamma R II and increased binding of Ag-IgG complexes (both greater than 200%). In contrast, B lymphocytes cultured with either IL-4 or anti-mu show a marked loss (85-90%) of binding of Ag-IgG complexes that is specific, time and temperature dependent, and reversible. Decreased binding of complexes was not due to decreased expression of the receptor and therefore appears to be due to some form of alteration of the receptor. Based on the observation that the loss of binding of complexes requires protein synthesis, we favor the view that the loss is due to association of Fc gamma R II with another membrane molecule whose expression is induced or increased by IL-4 or anti-mu. Anti-mu induced loss of Fc gamma R II ligand binding capacity does not require cross-linking of surface IgM because the effect can be generated with F(ab') anti-mu. Anti-mu induced loss of Fc gamma R II binding of complexes was substantially prevented by IFN-gamma, whereas IFN-gamma did not reduce the anti-mu caused increase in expression of MHC class II molecules. This result shows that increased expression of the latter molecules can be dissociated from loss of Fc gamma R II ligand binding capacity. A myeloid cell line was identified that constitutively expresses Fc gamma R II binds relatively few complexes. This cell line may be useful in identifying alterations of Fc gamma R II which lead to the loss of binding of complexes. These results indicate that various B lymphocyte activators have different effects on B lymphocyte expression and function, and can thereby affect Fc gamma R II generated regulatory signals.
NMR-based Model Reveals the Structural Determinants of Mammalian Arylamine N-Acetyltransferase Substrate Specificity

Arylamine N-acetyltransferases (NATs) catalyze the acetylation of arylamines, a key step in the detoxification of many carcinogens. The determinants of NAT substrate specificity are not known, yet this knowledge is required to understand why NAT enzymes acetylate some arylamines, but not others. Here, we use NMR spectroscopy and homology modeling to reveal the structural determinants of arylamine acetylation by NATs. In particular, by using chemical shift perturbation analysis, we have identified residues that play a critical role in substrate binding and catalysis. This study reveals why human NAT1 acetylates the sunscreen additive p-aminobenzoic acid and tobacco smoke carcinogen 4-aminobiphenyl, but not o-toluidine and other arylamines linked to bladder cancer. Our results represent an important step toward predicting whether arylamines present in new products can be detoxified by mammalian NATs.
Stress pathways and heart failure.

Stress-related pathways can be linked to each of these four pieces of the dilated cardiomyopathy puzzle: biomechanical stimuli, cytoskeletal signaling, myocyte survival, and SR calcium cycling. While the “cholesterol” of dilated cardiomyopathy has yet to be identified, genetic clustering suggests the likelihood that chronic increases in wall stress mediated via cytoskeletal pathways may lead to the concomitant activation of downstream effects on myocyte survival, apoptosis, hypertrophy, and calcium cycling that drive the progression of heart failure. If such is the case, it may become possible to reverse the process of dilated cardiomyopathy by relieving wall stress at the molecular level. Given the pace and quality of recent work from many laboratories, the solution to the puzzle of heart failure may be closer than previously imagined.
Policing mayberry: The work routines of small-town and rural officers

Much of the prior literature concerning police behavior has focused on the activities and citizen interactions of officers employed by large agencies located in urban jurisdictions. Using data collected through the systematic observation of police officers employed by small-town and rural agencies, the present study explores issues related to the work of police officers in smaller jurisdictions. Specifically, we present observational data that provides a detailed description of how these officers spend time on their shifts. In addition, observational data is used to identify the problems these officers confronted, as well as their relationship with the citizens they encountered. Similarities and differences between observed small-town and rural officers and their more urban counterparts are identified and discussed.
Probability maps of sequential glaucoma-scope images help identify significant change.

PURPOSE The purpose of this study was to identify areas of the optic disc showing high variability of repeated depth measurements, and to minimize the effect of baseline variability in interpretation of possible change over time using the Glaucoma-Scope. METHODS Seventy-four eyes from 70 subjects were analyzed with the Glaucoma-Scope. Three images were obtained on each of two separate sessions during the same day. At each location, the mean depth of the three images for each session was calculated to create a "baseline image." A contour map of standard deviation (SD) values at each topographic location was created for each subject reflecting local variability at different parts of the disc. The contour map and disc photograph were compared to determine what photographic features predicted high variability. A modified two-sample t-test was used at each topographic location to obtain p-values for the likelihood that a difference in mean depth between sessions was attributable to measurement variability alone. RESULTS Contour plots of SD for most subject eyes showed high variability in steeply sloped areas of the disc and along large blood vessels, with low variability near the cup center. The use of probability plots for significance of depth changes between test sessions automatically accounted for increased pointwise variability. The proportion of topographic locations showing statistically significant change but attributable to chance variation when no true change has occurred approximated the predicted proportion based on our modified t-test model. CONCLUSION A contour map of standard deviations of depth based on Glaucoma-Scope baseline images can identify areas of the disc with high variability. Statistical methods such as probability maps that account for local variability in the baseline image may be helpful in distinguishing true change from artefactual change over time.
Suggestions for the diagnostic study of a patient with an abnormal X-ray shadow of the chest.

The diagnosis and work-up of a patient with an abnormal x-ray shadow of the chest is dependent upon, first of all, a detailed history and physical examination. Second, it is important to remember that the roentgenologist's diagnosis is only an impression, and that although the description of the lesion as he sees it is accurate and his interpretation of the cause of the lesion may be highly correct, he still cannot make a histological or bacteriological diagnosis from the film. The ultimate diagnosis remains the province of the physician and in most instances the diagnosis can be established in the manner outlined above.
Hodograph transformation methods in incompressible second grade fluid

Abstract Solutions for the equations of motion of a steady plane flow for a second grade fluid are obtained by using hodograph transformation techniques and the results are compared with the corresponding solutions for viscous fluids.
An Experimental Investigation Into the Effects of Chemical Type on CO2/Heavy-Hydrocarbon Phase Behavior

Etude des compositions chimiques et des equilibres de phase liquide/vapeur de sept systemes huile/dioxyde de carbone afin d'emaliorer les traitements de recuperation de petrole par injection de dioxyde de carbone. Les huiles utilisees sont des melanges de fractions paraffiniques legeres et de fractions plus lourdes composees de paraffines, de naphtenes ou d'aromatiques. L'influence de la composition chimique de l'huile sur sa miscibilite dans le CO 2 et sur son gonflement est determinee
A mucopyocele of the clivus: case report

OBJECTIVE AND IMPORTANCE : There are increasing reports of nasal sinus mucopyoceles eroding the base of the cranium and causing the rapid onset of neurological complications. Uncommon presentations can mimic tumors, but the infectious nature mandates an urgent surgical decompression. It is important to document these uncommon presentations. CLINCIAL PRESENTATION : A mucopyocele of the clivus is reported in a patient with a frequent history of sinusitis. Diplopia caused by an acute sixth nerve palsy prompted the radiological diagnosis with computed tomography and magnetic resonance imaging. INTERVENTION : Transsphenoidal drainage of the lesion lead to marked improvement in the patient. CONCLUSION : This is the third reported case of a clival mucocele. Mucoceles of nasal sinuses can erode intracranially, causing neurological sequalae, and clival involvement is extremely rare. Early drainage leads to marked improvement.
Different levels of complexity in the play-fighting by muroid rodents appear to result from different levels of intensity of attack and defense

Play-fighting in deer mice, Peromyscus maniculatus bairdii, prairie voles, Microtus ochrogaster, and montane voles, M. Montanus, was compared to that of laboratory rats, Rattus norvegicus. Play in rats appears more complex for two reasons: 1) more of the playful contacts elicit defensive behaviors, and 2) more of these defenses lead to counterattacks, and hence, role reversals between attackers and defenders. Neither high levels of defense, as shown by montane voles, nor high levels of counterattack, as shown by prairie voles, produce rat-like play-fighting. This only occurs when high rates of defense involving turning to face the attacker and counterattack are combined, as in rats. These two components are rarely combined together by deer mice, and so this species rarely exhibits rat-like play-fighting. Furthermore, playful counterattack appears to arise from playful attack, and not from an escalation of defense. These data suggest that the more complex forms of social play, such as play-fighting, have evolved, in part, via the escalation of defense in response to playful attack.
Aluminum-Rich Al-MoO3 Nanocomposite Powders Prepared by Arrested Reactive Milling

Fuel-rich Al-MoO 3 nanocomposites were prepared using arrested reactive milling. Powder composition was varied from 4Al + MoO 3 to 16Al + MoO 3 . Powders were evaluated using electron microscopy, thermal analysis, x-ray diffraction, heated-filament-ignition experiments, and constant-volume-explosion experiments. Uniform mixing of MoO 3 nanodomains in the aluminum matrix was achieved for all prepared powders. Multiple and overlapping exothermic processes were observed to start when the nanocomposite powders were heated to only about 350 K. In heated-filament experiments, all nanocomposite powders ignited at temperatures well below the aluminum melting point. Ignition temperatures for these powders were estimated for the higher heating rates that are typical of fuel-air explosions. Constant-volume-explosion experiments indicated that flame propagation in aerosols of nanocomposite thermite powders in air is much faster than that in pure aluminum aerosols. The energy release, normalized per unit mass of aluminum, was higher for the nanocomposite materials with bulk compositions 4Al + MoO 3 and 8Al + MoO 3 and lower for pure aluminum and for the 16Al + MoO 3 nanocomposite sample. The reaction rate was the highest for the 8Al + MoO 3 nanocomposite powder. The combustion efficiency inferred from the measured pressure traces correlated well with the phase compositions of the analyzed condensed combustion products.
The several costs of responding to the threat of terrorism

This paper describes several dimensions of the cost of the U.S. response to the threat of terrorism. Following an evaluation of the nature and magnitude of the threat of terrorism against the United States, the paper describes the restrictions on our civil liberties, the fiscal and other costs of the major homeland security measures, the fiscal cost of programs that make no contribution to the defense against terrorism but are rationalized on that ground, and the effects on our language and the potential for civil discourse of an extended defense against terrorism.
Design and characterization of MEMS micromotor supported on low friction liquid bearing

Abstract This paper examines the performance of rotating microdevices incorporating a liquid bearing to couple a rotating element to a fixed substrate. Liquid bearing technology promises to significantly improve the durability and lifetime of micromechanical motors. Here, the fluid is confined between the rotor and stator using surface patterning of a hydrophobic layer. Magnetic actuation of 10 mm diameter silicon rotor is used to characterize the liquid bearing motor at rotation rates up to 1800 rpm. Bearings with fluid thickness from 20 to 200 μm are characterized. A minimum torque of 0.15 μN-m is required to initiate rotation. At rotation rates above 720 rpm, the rotor wobble is less than ±1 mrad and the bearing exhibits viscous friction with a drag coefficient of 1.2 × 10 −3 μN-m/rpm. The drag performance of the disk-type liquid bearing using H 2 O as the fluid is approximately 15 times lower than that demonstrated in a micro-ball bearing supported rotor.
Heat transfer and thermal boundary layer in a conical nozzle.

Inlet thermal boundary layer thickness effect on conical nozzle heat transfer and boundary layer determined by operating nozzle with cooled/ uncooled inlet
A simple method for vacuum sealing radioactive sources

Abstract Described is a relatively simple method for sealing radioactive sources containing compounds or elements that sublime so that they may be used in evacuated systems without causing contamination. The method was used to seal several Hg 203 sources that were subsequently used for several weeks at a pressure of 5 × 10 −5 mm Hg with no vacuum system contamination.
Diterpenes of Larix oleoresins

Abstract Oleoresins from most species of the genus Larix have been analysed by GLC for their diterpene composition. Common to all are the abietadiene and isopimaradiene acids usual in Pinaceae with the corresponding aldehydes and alcohols in small amounts. Epimanool also occurs in all, but larixol and its acetate is confined to L. decidua and L. gmelini , and epitorulosol to the remainder. In the hybrid L. Xeurolepis both of these last two compounds are present.
Sub-Doppler stark spectroscopy in the A-X (1,0) band of CN.

The effect of external electric fields has been measured in hyperfine-resolved sub-Doppler transitions in the A {sup 2}{Pi}-X {sup 2}{Sigma} (1,0) band of the CN radical near 10900 cm{sup -1}. Static electric fields less than 1 kV/cm are sufficient to mix the most closely spaced {Lambda}-dpublets in the A state, leading to Stark spectra with both new and shifted resonances. Simulations of the saturation-dip Stark spectral line profiles allow extraction of the A-state permanent electric dipole moment with a magnitude of 0.06 {+-} 0.02 D.
Binding of a [14C]hydrocortisone metabolite in liver supernatant.

Abstract Forty-five min following the administration of non-inducing, tracer doses of labeled hydrocortisone to adrenalectomized rats, approx. 49% of the total radioactive material in the 100 000 × g siver supernant was shown to be bound to macromolecules using the technique of ultrafiltration. These macromolecules, apparently proteins, differ from the hydrocortisone-binding proteins of the serum by virtue of their smaller size their inability to bind hydrocortisone in vitro . Most of the radioactive material from the liver supernatan, following injection of the isotope in vivo , consisted of at least three electrophoretically distinct, negatively charged components. No more than 6% of the total radioactivity could be accounted for by metabolically unaltered hydrocortisone. The ability of the hormone to bind to intracellular proteins strongly may depend upon prior conversion of the hormone to an anionic form(s).
λ Repressor inactivation: Properties of purified ind− proteins in the autodigestion and RecA-mediated cleavage reactions

Under physiological conditions, lambda repressor can be inactivated in vivo or in vitro by RecA-mediated cleavage of the polypeptide chain. The repressor protein is thought to cleave itself, with RecA acting to stimulate autodigestion. ind- repressor mutants are resistant to RecA-mediated inactivation in vivo. In this paper, we report the purification of 15 ind- repressor proteins and the behaviors of these proteins in the RecA-mediated and autodigestion cleavage reactions. None of these proteins undergoes substantial RecA-dependent cleavage. However, eight mutant proteins autodigest at the same rate as wild-type repressor, six mutants do not autodigest or autodigest slower, and one mutant autodigests faster than wild-type. We discuss these results with respect to repressor structure and RecA-binding, and suggest possible roles for the RecA protein in the cleavage reaction.
Nanoscale Structural Engineering via Phase Segregation: Au-Ge System

A tunable structural engineering of nanowires based on template-assisted alloying and phase segregation processes is demonstrated. The Au−Ge system, which has a low eutectic temperature and negligible solid solubility (<10−3 atom %) of Au in Ge at low temperatures, is utilized. Depending on the Au concentration of the initial nanowires, final structures ranging from nearly periodic nanodisk patterns to core/shell and fully alloyed nanowires are produced. The formation mechanisms are discussed in detail and characterized by in situ transmission electron microscopy and energy-dispersive spectrometry analyses. Electrical measurements illustrate the metallic and semiconducting characteristics of the fully alloyed and alternating Au/Ge nanodisk structures, respectively.
Surface oxidation effects on the optical properties of silicon nanocrystals

We report first-principles calculations for optical absorption spectra of hydrogenated silicon clusters in the presence of oxygen on the surface. Our computational technique is based on linear-response theory within the time-dependent local-density approximation (TDLDA). The calculated spectra show that oxidation substantially reduces the size of optical gaps in silicon nanocrystals. This result may explain a seeming disagreement between the measured photoluminescence and theoretical predictions based on a quantum confinement model in the limit of small clusters.
So Slow to Change: The Limited Growth of Nontax Revenues in Public Education Finance, 1991–2010

We examine changes in the use of nontax revenues for education finance from 1991 to 2010. Beyond the summary of usage over time, we ask whether nontraditional revenues like fees accentuate or mitigate the impact of downturns. More generally, we examine the extent to whichschooldistrictshaverespondedtofiscalpressures by turning to nontax revenues. We also document the extent to which the use of nontax revenues varies across districts according to student poverty status. We show that alternative revenues continue to be a small source of local revenues and have increased quite little since the early 1990s. There was at most a minimal shift to nontaxrevenuesindownturns,thoughthereisevidence of greater use of these revenues among school districts facing more permanent fiscal pressures like tax limits. Differential access to fee revenues and other alternative revenues during downturns may slightly accentuate inequities in K‐12 education spending.
Beyond the Nucleosome: Epigenetic Aspects of Position–Effect Variegation in Drosophila

Studies of PEV are providing important insights into the mechanisms that influence chromatin structure beyond the level of the nucleosome. A surprisingly large network of proteins influences PEV and heterochromatin formation in Drosophila. Recent molecular studies have provided a better understanding of the potential roles of these proteins. However, more extensive analyses of the physical interactions among these proteins, their DNA- and chromosome-binding properties, and their roles in gene expression are required to build more precise molecular models that accommodate the known biological functions of heterochromatin and explain the multiple genetic and epigenetic mechanisms of PEV.
Gastric aspiration in fiber optic endoscopy

One hundred nonemergency fiber optic gastroscopies were performed both with and without preceding gastric aspiration. It was found that in most cases the ability to change the position of the patient rendered unnecessary the traditional procedure of gastric emptying.
Clinical— experimental analysis of design problem solving

Abstract Two studies of desgin problem solving are'reported. Experiment 1 presents an observational study of an actual client-designer worksession. Analysis of the session transcript reveals a systematically structured interaction. The client and the designer decompose the overall design problem into subproblems, each of which is smaller and somewhat more well structured that the overall problem. Experiment 2 is a laboratory study. The ‘client’ role is simulated by an instruction booklet; subjects play the ‘designer’ role. Again, it is found that subjects spontaneously structure the elements of a design problem into subproblems the nature of which is systematically related to aspects of problem structure. There is high intersubject agreement as to how the decomposition into subproblems should proceed.
Bowker's Structuralist Theology

Christi College, Cambridge, has probed the new behavioral sciences' import for the old question of God's reality. Drawing from information theory, linguistics, structuralism, phenomenology, and other new fields, Bowker shows that God's objectivity seems to be returning to possibility. My purpose in this article is twofold. First, I wish to underscore the character of this more platsibly objective God that the new behavioral sciences are allowing or even suggesting. This will involve sketching the overall argument of The Sense of God and then focusing on its structural designation of God as regressive. Second, I wish to react to the hints Bowker gives of how God's objective reality might be indicated and argued for. This will involve criticizing The Sense of God's structuralism. The result, I hope, will' be to show that Bowker is on the right track, though not sufficiently interiorized, and that "regressive" is a useful contemporary reminder of past apophatic theology.2
Hybrid III-V-on-Silicon Microring Lasers

Hybrid silicon laser is a promising solution to enable high-performance light source on large-scale, silicon-based photonic integrated circuits (PICs). As a compact laser cavity design, hybrid microring lasers are attractive for their intrinsic advantages of small footprint, low power consumption and flexibility in wavelength division multiplexing (WDM), etc. Here we review recent progress in unidirectional microring lasers and device thermal management. Unidirectional emission is achieved by integrating a passive reflector that feeds laser emission back into laser cavity to introduce extra unidirectional gain. Up to 4X of device heating reduction is simulated by adding a metal thermal shunt to the laser to “short” heat to the silicon substrate through buried oxide layer (BOX) in the silicon-on-insulator (SOI) substrate. Obvious device heating reduction is also observed in experiment.
Progress in production-worthy point contact solar cells process

This work reports on the integration process of rear point contact solar cells with reduced recombination and better light trapping than the conventional cells. Al 2 O 3 /SiN x passivation stacks were used to ensure the backside passivation and the effective lifetime of minority carrier is found to be >100 µs (estimated surface recombination velocity ∼50 cm/s) on solar p-type Cz wafers. The estimated fixed charge associated with the Al 2 O 3 is in the range of −5e12 C/cm2. Laser ablation of Al 2 O 3 /SiN x stack and aluminum alloying are studied in detail to understand the process window for clean ablation and back surface field. It is found that laser energy plays an important role cleanly ablating the Al 2 O 3 /SiN x passivation stack. The solar cell is fabricated using standard processes based on screen-printed aluminum paste onto laser ablated passivation layer consisting of Al 2 O 3 /SiN x . Aluminum alloying is dependent on the firing profile and amount of Al melted into Si. Back point contact cells show improvements in J sc by 1 mA/cm2 and V oc by 10 mV due to better response in infrared spectrum. The best conversion efficiency of back point contact solar cells fabricated with standard industrial emitter and backside passivation is 19.35%.
Spatial and temporal patterns of active layer thickness at Circumpolar Active Layer Monitoring (CALM) sites in northern Alaska, 1995–2000

[1] Maximum annual development of the active layer above permafrost has been monitored at seven 1-km2 Circumpolar Active Layer Monitoring (CALM) sites in northern Alaska since 1995. Grid nodes are spaced at 100-m intervals, yielding a regular array of 121 (11 × 11) data collection points. Three sites are located in the Arctic Foothills physiographic province, and four are on the Arctic Coastal Plain. Air and soil temperature measurements are made at each site, and soil moisture is monitored at most. Six years of record permit several general conclusions: (1) At the landscape scale, end-of-season thaw depth is strongly correlated with local air temperature on an interannual basis. All sites experienced maximum average thaw depth in 1998 and a minimum in 2000, consistent with the warmest and coolest summers during the period of record. The active layer, however, may exhibit Markovian behavior over multidecadal periods. (2) There is significant intrasite variation in thaw depth and near-surface soil moisture content within each 1-km2 grid, reflecting the local influence of vegetation, substrate properties, snow cover dynamics, and terrain. (3) On the Coastal Plain, thaw depth is significantly greater in drained thaw-lake basins, resulting in a bimodal distribution of thaw depth related to primary landscape elements. (4) Foothills sites demonstrate large spatial and interannual variability resulting from microtopography and temporal variations of soil moisture content, making predictive mapping of thaw depth problematic at the scale and resolution of the grids. The spatial pattern of thaw depth across sites on the Coastal Plain is relatively consistent, although lake margins exhibit more complex patterns attributable to fluctuating water levels.
Applicability of the ratchet model to the polarization of charge density waves below the threshold field

Abstract Using perturbation theory and computer simulations, it is shown that a simplified model for charge density wave dynamics, in which the sinusoidal potential of the Fukuyama-Lee model is replaced by a ratchet potential, is equivalent to that model in the large potential limit, at least for phenomena below threshold.
Emergence of a subpopulation of lymphocytes bearing θ antigen and complement receptor during tumor growth

Spleens from BALB/c mice transplanted with mammary tumors display a significant increase in the percentage of lymphocytes bearing complement receptors (CRL) while the percentage of cells bearing surface immunoglobulins (SIg) remains unchanged in comparison with that in spleens from normal animals. Upon separation on nylon columns, the increase in CRL in the spleens from tumor-bearing mice was limited to the non-adherent cell population. Simultaneous marker analysis disclosed that these CRL lacked detectable SIg. Indirect immunofluorescence indicated that these cells possessed theta antigen. Absence of SIg and the presence of theta antigen coupled with the restricted occurrence of these cells in the nylon-non-adherent population which responded to PHA and Con A but not to LPS indicate that these cells may constitute a subset of T cells. The paucity of this subpopulation of spleen lymphocytes in normal spleen suggests that their emergence is related to tumor growth. Apparition D'une Sous-Population De Lymphocytes Portant L'antigene θ Et Les Recepteurs Du Complement Pendant La Croissance Tumorale Dans la rate de souris BALB/c porteuses de tumeurs mammaires transplantees, on a constate une augmentation significative du pourcentage de lymphocytes portant des recepteurs pour le complement (CRL), tandis que le pourcentage de cellules portant des immunoglobulines a leur surface (SIg) restait inchange par comparaison avec la rate des animaux normaux. Lors de la separation sur des colonnes de nylon, on a constate que l'augmentation des CRL spleniques des souris porteuses de tumeurs ne se produit que dans la population de cellules non adherentes. Une analyse simultanee des marqueurs a revele que ces CRL ne portent apparemment pas de SIg. L'immunofluorescence indirecte a indique que ces cellules possedent l'antigene theta. L'absence de SIg et la presence de l'antigene theta, associees au fait que ces cellules n'apparaissent que dans la population non adherente au nylon qui reagit a la PHA et a la Con A mais pas au LPS, indiquent qu'il s'agit peut-ětre d'une sous-population de cellules T. La rarete de ces lymphocytes spleeniques dans la rate normale conduit a penser que leur apparition est liee a la croissance tumorale.
Analysis of the Effect of Spatial and Temporal Sampling Densities on Accuracy of Predicting the Heating Profile in Windrowed Broiler Litter

A standard method for monitoring temperature in windrow piles of broiler litter to predict microbial population reductions is described. Temperature data collected every 2 min on a 10 cm x 10 cm spatial sampling grid in five identically-constructed litter windrow piles was utilized in this study. A Weibull distribution was fit to mean temperature response (MTR) curves of each pile. Curves were constructed at sample intervals parsed over a range of two to 1000 minutes. No difference in Weibull shape or scale parameters was observed among the analyzed sample intervals. A difference (P<0.05) in mean standard error of Weibull distribution fit parameters was identified between the 200- and 400-min sample intervals. Further analysis between the 200- and 400-minute sample intervals did not reveal a more appropriate value for optimal temporal sampling frequency. Optimal spatial sampling density was characterized using ordinary kriging analysis. Ordinary kriging was used to predict the cross-sectional areas of piles reaching specified time-temperature goals. Eight spatial sampling grid configurations were analyzed. Mean (n=5) predicted cross-sectional area (CSA) reaching 40°C for 120 h differed significantly (P<0.05) between the 30 cm x 20 cm and 30 cm x 30 cm grid spacing configurations. Accuracy of predicted pile CSA decreased as spatial sampling density decreased. This data will be beneficial when designing future windrow composting temperature monitoring studies.
A prospective, controlled study of the effects of hormonal contraception on bone mineral density ☆

Abstract OBJECTIVE: To compare the effect of depot medroxyprogesterone acetate (DMPA) and two types of oral contraceptives (OC) on bone mineral density (BMD) among women 18–33 years of age with those not using hormonal contraception. METHODS: Data from 155 women were analyzed. Depot medroxyprogesterone acetate was administered to 33 women; 63 women who chose oral contraception were randomly assigned to receive either a norethindrone-containing pill ( n = 28) or a desogestrel-containing pill ( n = 35). Fifty-nine women who did not use hormonal contraception served as controls. Lumbar spine BMD was determined using dual-energy x-ray absorptiometry at baseline and after 12 months of contraceptive use. We analyzed method-related percent change in BMD while controlling for body mass index, calcium intake, exercise, and smoking. We had approximately 90% power to detect a 2.5% difference between any two groups. RESULTS: Users of DMPA experienced a mean BMD loss of 2.74% over 12 months compared with controls who sustained a 0.37% loss ( P = .01). Users of OCs generally demonstrated a gain (2.33% for norethindrone-containing pills, 0.33% for desogestrel-containing pills), which was different from controls among users of norethindrone-containing pills ( P = .01), but not among users of desogestrel-containing pills ( P = .99). Observed changes in BMD among DMPA users differed from women who used either type of pill ( P CONCLUSION: Depot medroxyprogesterone acetate has an adverse effect on BMD, in comparison with OCs or nonhormonal methods, when used for 12 months. Results must be interpreted cautiously until it is determined whether these effects endure or are reversible.
Phase II trial of sunitinib in patients with metastatic non-clear cell renal cell carcinoma

Sunitinib is associated with a robust objective response rate in patients with metastatic clear cell renal cell carcinoma (RCC). The primary objective of this phase II clinical trial was to assess the overall response rate for sunitinib in patients with papillary metastatic RCC as well as other non-clear cell histologies. A Simon 2-stage design was used to determine the number of papillary metastatic RCC patients for enrollment, and allowed for descriptive response data for other non-clear cell histologies. Twenty-three patients were enrolled, including 8 with papillary renal cell carcinoma (RCC) and the remainder with other non-clear cell histologies (unclassified in 5 patients). All patients received 50 mg of oral sunitinib in cycles of 4 weeks followed by 2 weeks of rest (4/2). The trial was stopped early because of slow accrual; no responses were observed in the 8 patients with papillary RCC. In the 22 evaluable patients, best response to sunitinib included a partial response in 1 patient with unclassified RCC, stable disease in 15, and progression in 6. The median progression-free survival was 5.5 months (95% CI, 2.5–7.1) in all 23 patients, and 5.6 months for the 8 papillary patients (95% CI, 1.4–7.1). The robust objective responses sunitinib had produced in clear cell RCC could not be demonstrated in this study comprised of patients with non-clear cell histologies.