cssi/SciSciGPT-SciSciNet huggingface dataset:
Modulation of EPSP amplitude during high frequency stimulation depends on the correlation between potentiation, depression and facilitation

Abstract High frequency bursts were delivered every 2 s to single group Ia fibers in anesthetized cats. The modulation of EPSP amplitude in target motoneurons was determined. Changes in EPSP amplitude during the high frequency stimulation (facilitation or depression) were correlated with those occurring 2 s after the burst (potentiation). Connections displaying high levels of potentiation exhibited more depression resulting in a net negative modulation. Negative amplitude modulation was greatest at connections on low rheobase (‘small’) motoneurons that develop large EPSPs. Positive modulation occurred at a subset of connections on high rheobase (‘large’) motoneurons that exhibit small EPSPs. We suggest that these synaptic properties permit the appropriate amount of depolarization to be delivered to the heterogenous elements of the motoneuron pool during high frequency Ia fiber activity characteristic of the step cycle.
5,5-dimethyl-5H-dibenzo[b,f]silepin: A 14π-electron silicon heterocycle

Abstract 5,5-Dimethyl-5 H -dibenzo[ b,f ]silepin and its 10,11-dihydro-analogue have been prepared and have been studied by NMR, UV, and mass spectral techniques. The data have been evaluated on the basis of comparisons between these two new compounds themselves, and between them and known carbon analogues, with particular attention to the matter of possible Si(3 d π)C(2 p π)conjugation. The results indicate ( p  d )π-orbital interactions to be minimal. Mass spectral evidence gives no indication of unusual stability for the potentially “aromatic” siliconium ion derivable from the title compound.
Carbon isotopic fractionation in live benthic foraminifera—comparison with inorganic precipitate studies

Carbon and oxygen isotopic analyses have been performed on live-stained aragonitic and calcitic benthic foraminifera and dissolved inorganic carbon (DIC) from the Southern California Borderland to examine carbon isotopic fractionation in foraminifera. Temperature, salinity and pH data have also been collected to permit accurate determination of the δ13C of bicarbonate ion and thus aragonite-HCO3 and calcite-HCO−3 isotopic enrichment factors (ϵar-b and ϵcl-b, respectively). Only species which precipitate in 18O equilibrium have been considered. ϵar-b values based on Hoeglundina elegans range from 1.9%. at 2.7°C to 1.1%. at 9.5°C. Only the lower temperature values agree with a tentative carbon isotope equilibrium equation for aragonite based on the data of Rubinson and Clayton (1969) and Emrich et al. (1970). The temperature dependence of ϵar-b is considerably greater than the equilibrium equation would predict and may be due to a vital effect. The calcitic foraminifera Cassidulina tortuosa, Cassidulina braziliensis, and Cassidulina limbata, Bank and Terrace dwellers, have similar δ13C values and yield an average ϵcl-b value of −0.2 ± .1%. between 8° and 10°C. Calcitic Uvigerina curticosta, Uvigerina peregrina, and megalospheric B. argentea, Slope and Basin dwellers, are −0.7 ± .1%. enriched relative to ambient bicarbonate for 3 to 9°C. No temperature dependence for ϵcl-b was observed for the species in either habitat. The ϵcl-b values for Cassidulina species are close (± 0.3%.) to the values given by the tentative equilibrium curve for calcite, while Uvigerina and Bolivina species give values 0.2–0.8%. less. The ϵcl-b difference between the Cassidulina species and the Uvigerina and Bolivina species is attributed to the incorporation of 13C-depleted pore water DIC by the latter group rather than to taxonomic or temperature differences.
Perfusion chromatography . The effects of intra-particle convective velocity and microsphere size on column performance

A mathematical model describing the dynamic adsorption in columns with spherical bidisperse perfusive or spherical bidisperse purely diffusive adsorbent particles is presented and its solution is obtained numerically. The adsorption of bovine serum albumin on spherical anion-exchange porous particles was studied for different values of the intraparticle Peclet number, Peintra, and of the microsphere diameter, dm. The results show a departure from spherical symmetry of the isoconcentration profiles of the adsorbate in the porous adsorbent particle as Peintra increases. This spherical asymmetry increases the adsorbate availability in the pore fluid of the macroporous region and also increases the concentration of the adsorbate in the adsorbed phase in the upstream half of the spherical adsorbent particle. If, for example, the concentration profiles of the adsorbate in the adsorbed phase of the porous adsorbent particles could be determined experimentally and if these profiles show a departure from spherical symmetry, then this result could suggest that the porous adsorbent particles may have exhibited perfusion behavior under the conditions of operation of the column. The dynamic percentage utilization of the adsorptive capacity of the column increases as Peintra increases and dm decreases. The percentage breakthrough to be selected for column switching is influenced by the magnitude of Peintra because of its effect on the dynamic percentage utilization of the adsorptive capacity of the column.
Sequential phases of covert reinforcement and covert sensitization in the treatment of homosexuality

Abstract A two-phase therapy plan was used in the treatment of a 21-year-old male homosexual. Following a one week baseline period during which he counted the daily frequency of homosexual and heterosexual urges, homosexual fantasies were used for covert reinforcement of heterosexual urges. The second phase of treatment consisted of decreasing the daily frequency of homosexual urges by covert sensitization.
Crystallization of Fe(NH4)2 (SO4)2.6H2O on a seed in magnetic fields up to 140 kOe

Abstract The present communication reports isothermal crystal growth experiments in high magnetic fields. We find that both the isothermal linear velocity of growth or dissolution R of a seed of Fe (NH4)2 (SO4)2 . 6H2O is increased when a magnetic field H is applied. The magnitude of the increase in R for growth at H = 83 kOe is equivalent to the increase in R obtained by a decrease in temperature of 1°K. The total temperature fluctuation in the experiments is ± 0.05°K. The direction of maximum growth is at an angle of 40–60° relative to H. No satisfactory quantitative model has yet been developed to explain the new experimental data.
220 EFFECT OF THYROID HORMONE ON TISSUE NERVE GROWTH FACTOR (NGF) CONCENTRATIONS IN THE MOUSE

NGF is a protein which has a wide tissue distribution in the mouse and is able to stimulate growth, maturation, and function of autonomic neurons. Because thyroid hormone also is known to affect nervous system growth and function, it is possible that some of its effects may be mediated through NGF. Using a newly developed, highly sensitive (10-20 pg) radioimmunoassay (RIA) for β-NGF, we studied the effects of thyroxine (T4) and propylthiouracil (PTU) on NGF concentrations in several tissues of the adult male mouse. T4 (25 μg i.p. daily × 12 days) caused a significant increase in submaxillary gland and liver NGF concentrations (180 and 225% respectively) compared to controls (p<0.001), when expressed relative to wet weight or supernatant protein. There was no consistent effect on kidney NGF concentration. PTU (0.05% in drinking water × 21 days) led to a reduction in kidney NGF to 25% of control values (p<0.001) with no discernible effect in sub-maxillary gland and liver NGF concentrations. Conclusions: 1) A highly sensitive RIA for NGF has been developed. 2) T4 appears to have a significant effect on the concentration of NGF in sub-maxillary gland and liver of the adult male mouse, while PTU-induced hypothyroidism affects kidney NGF. These observations in adult mice suggest that thyroid hormone may play an important regulatory role in NGF metabolism.
Vortex: an optimizing compiler for object-oriented languages

Previously, techniques such as class hierarchy analysis and profile-guided receiver class prediction have been demonstrated to greatly improve the performance of applications written in pure object-oriented languages, but the degree to which these results are transferable to applications written in hybrid languages has been unclear. In part to answer this question, we have developed the Vortex compiler infrastructure, a language-independent optimizing compiler for object-oriented languages, with front-ends for Cecil, C++, Java, and Modula-3. In this paper, we describe the Vortex compiler's intermediate language, internal structure, and optimization suite, and then we report the results of experiments assessing the effectiveness of different combinations of optimizations on sizable applications across these four languages. We characterize the benchmark programs in terms of a collection of static and dynamic metrics, intended to quantify aspects of the "object-orientedness" of a program.
Identifying in-hospital venous thromboembolism (VTE): a comparison of claims-based approaches with the Rochester Epidemiology Project VTE cohort.

Background:Efforts to identify hospital-acquired complications from claims data by applying exclusion rules to discharge diagnosis codes exhibit low positive predictive value (PPV). The PPV improves when a variable is added to each secondary diagnosis to indicate whether the condition was “present-o
Response to "The need to evaluate question writers' views and the costs of constructed-response versus selected-response calculations questions".

In reply: Thank you for the inquiries about our article “Pharmacy Student Performance on Constructed-Response Versus Selected-Response Calculations Questions.”1 You noted a few areas that we had designated to discuss in a subsequent article. Test writing, as you suggested, is a time-intensive activity that requires expertise not typically held by traditional pharmacy faculty members. Developing tests is a specialized skill that may be underestimated by both new and seasoned faculty members. Personnel with backgrounds in statistics, education, and/or psychology may have had exposure to the intricacies of test writing, but it takes a great deal of time, experience, and expertise to develop high-quality assessments. In the case of selected-response vs constructed-response questions, writing constructed-response questions is actually easier and less time-intensive than writing selected-response questions; writing the answer choices is one of the most difficult tasks in developing selected-response questions. In terms of labor costs, faculty time is an important consideration, but the pharmacy schools of Shenandoah University and Union University do not have designated staff members to manage the question-writing process. The writing and approval process likely varies among colleges and schools of pharmacy. We do have technical staff members who are available to help with the online testing software and setup of tests. Shenandoah University pharmacy students have been using laptops and online testing extensively since the school opened in 1996, and Union University pharmacy students have been using laptops and online testing since the school opened in 2008. In that regard, there is no additional cost for hardware or software specifically related to computer-based pharmacy calculations quizzes or examinations. The use of the testing software for this purpose actually would provide additional justification for any current annual expenses related to hardware and software necessary for online testing.
Preferential interactions of guanidinum ions with aromatic groups over aliphatic groups.

Small angle neutron scattering (SANS) and molecular dynamics (MD) simulations were used to characterize the long-range structuring (aggregation) of aqueous solutions of isopropanol (IPA) and pyridi...
The cost of financial capital: Evidence from selected Caribbean countries

Does a strong commitment to an exchange rate peg reduce the cost of financial capital to less developed countries? We use a sample of twelve Caribbean countries to examine the impact that the Eastern Caribbean Currency Union (ECCU), a currency board/monetary union, has in lowering the cost of borrowing to its members. Results from estimations on individual and pooled annual data from 1976–1999 indicate that membership in the ECCU, in addition to other policy variables, significantly reduces the cost of financial capital.
Stress, social support, and problem-solving appraisal/skills: Prediction of suicide severity within a college sample

This study assessed whether stress, social support, and interpersonal problem-solving appraisal/skills were predictive of level of suicidality within a chronic suicidal college sample. Stepwise regression analyses were used to assess whether stress, social support, and problem-solving were independently predictive of severity of suicide ideation. In addition, hierarchical regression analyses were used to test the mediational nature of social support and problem-solving in the stress-suicidality relationship. Problem-solving confidence was found to be a significant predictor of severity of suicide ideation. In addition, both perceived problem-solving skills and social support mediated the relationship between stress and level of suicide ideation. However, only one of the two perceived problem-solving skills interactions was in the expected direction. This study provided support for the importance of problem-solving confidence and the interaction of stress and social support in the prediction of suicide severity. Unlike previous studies, this study did not find problem-solving skills/deficits to mediate the stress-suicidality relationship.
Q)SAR Modeling and Safety Assessment in Regulatory Review

The ability to predict clinical safety based on chemical structures is becoming an increasingly important part of regulatory decision making. (Quantitative) structure–activity relationship ((Q)SAR) models are currently used to evaluate late-arising safety concerns and possible nonclinical effects of a drug and its related compounds when adequate safety data are absent or equivocal. Regulatory use will likely increase with the standardization of analytical approaches, more complete and reliable data collection methods, and a better understanding of toxicity mechanisms. Clinical Pharmacology & Therapeutics (2012); 91 3, 529–534. doi:10.1038/clpt.2011.300
Thermochemical studies of energetics in active transport across Escherichia coli membranes

Abstract A thermochemical method was shown to be useful in the membrane active transport research. By employing microcalorimetry in conjunction with the reported transport data, the formation of a proton electrochemical potential (Δμ H+ ) across the membranes was confirmed from the thermochemical point of view. These membranes include proteoliposomes reconstituted from cytochrome o oxidase and membrane lipids as well as membrane vesicles prepared from Escherichia coli . Different electron-donor systems including dithiothreitol-ubiquinone, D-lactate-lactate dehydrogenase and ascorbate-phenazine methosulfate were used to provide the energy source for the active transport. Energetics information including the energy source, the proton electrochemical potential, the energy utilization and the coupling reactions were obtained. The energy transfers in the coupling reactions involving the oxidation of an electron donor and the formation of Δμ H+ were estimated. Comparative results were found in both membrane systems. The characteristic of the created Δμ H+ was independent of the energy source imposed on the membranes.
CRL membership: The library director's perspective

Since being asked to speak at this program, the question which has often crossed my mind is: Why me? 1 thought that it might be because I have been a member of the CRL Board for five years and consequently have a pretty good, idea of what the organization is attempting to do. Then I thought that what they wanted was, perhaps, the celebrity factor and that I had been invited because I am the President-Elect of the Association of College and Research Libraries. It wasn’t until I arrived in New Orleans last evening that the obvious reason occurred to me: How could they ask anyone but a Frenchman to speak in this Francophone environment! As you already know, I have been a member of the Board of Directors of the Center for five years. It is quite accurate to say that when I was elected to that office, my attitude toward CRL could best be described as that of a Doubting Thomas. Indeed, I was seriously considering withdrawing from participation in the Center. I decided, nevertheless, to give it a try and see what would happen. My direct involvement brought about a radical change in my attitude. I am now about as firm a supporter as there can be. So, I’m genuinely glad to have been invited to be here today. I’m going to give testimony, so to speak. And though mine certainly won’t be as colorful as Jimmy Swaggart’s might be, I’m confident that it will a lot more sincere. In recent years, I have become rather heavily immersed in the area of collection development. This direction occurred somewhat casually. When I first went to the University of California at Santa Barbara, I became a member of what is lovingly known within the UC system as Library Council. Composed of the nine University Librarians and representatives of the Office of the President, the University Senate, the Librarians’ Association of the UC, and the general campus administrations, the Council discusses policy issues related to UC libraries and advises the Office of the President on matters related to the libraries of the system. One of the committees of Library Council is the Collection Development Committee. Some would say it is not one of the more glamorous committees of Council, but then I’m not sure there are any committees of Council that could be characterized as glamorous.
Measuring increased engagement using tablet PCs in a code review class

The Programming Studio in the University of Illinois Computer Science department is a required course in which small groups of students participate in weekly code reviews of each other's programs. To increase student engagement in the discussions, Tablet PCs were introduced for several weeks in the middle of the semester. By recording the discussions before, during, and after the use of tablets, we measure the effectiveness of this intervention. In doing so, we develop a simple metric to measure the "active engagement" of the participants. We found each section was significantly more engaging when using Tablet PCs (p
Do Cognitive Changes Accompany Developments in the Adolescent Brain

The news that the brain continues to develop through much of adolescence risks becoming an explanation for anything and everything about teenagers and suggests the need for closer analysis. Central to such analysis is clarifying what develops at a psychological level during these years. An examination of contemporary research data on adolescent cognitive development identifies increased executive control as a major dimension of cognitive development during the second decade of life. Such development is consistent with changes occurring in the brain during this period.
The GABAa receptor-gated ion channel: Biochemical and pharmacological studies of structure and function

In the past few years, substantial advances have been made in analyzing the structure and function of the GABA receptor-gated Cl- channel. A major goal is to identify the molecular characteristics of the GABAA receptor that are necessary for maintaining normal GABAergic neurotransmission. Future studies will undoubtedly include techniques that have been used successfully to construct a detailed structural and dynamic model of the nACHR-gated ion channel. These include X-ray scattering, single group rotation theory, and genetic homology, deletion and site-directed mutation studies. Such techniques will make it possible to identify the structural defects that give rise to abnormal GABA receptor function and possibly to sleep, anxiety and seizure disorders.
Impact of thermal conductivity models on the coupling of heat transport and oxygen diffusion in UO2 nuclear fuel elements

We study the coupled thermal transport, oxygen diffusion, and thermal expansion of a generic nuclear fuel element consisting of a UO2 fuel pellet and stainless steel cladding separated by a helium gap for the purpose of evaluating the impact of various thermal conductivity models on the predictions of the temperature profile and deformation. Using a series of steady-state and time-dependent finite-element simulations with a variety of initial- and boundary-value conditions, thermo-mechanical response of the fuel element is evaluated. The results show that including the deviation from stoichiometry, x, in the thermal conductivity model is paramount for obtaining accurate predictions in the centerline temperature and the extent of the radial deformation of the fuel pellet. In a surprising result, the coupling between the heat transport and the oxygen diffusion is relatively strong for small values of the fixed composition boundary conditions xb, whereas the coupling becomes weaker for large values of xb.
The relationship between cell division and cell specialization in the mouse intestinal epithelium.

Der Zusammenhang zwischen der Teilung von Ursprungszellen und der Differenzierung ihrer Tochterzellen wurde anhand von Epithelzellen des Duodenums weisser Mauser untersucht. Um den Zustand des «steady state» zu erhalten, finden die folgenden Arten von Teilung der Ursprungszellen statt: 1) zwei neue Ursprungszellen; 2) zwei differenzierte Tochterzellen; oder 3) eine neue Ursprungszelle und eine differenzierte Tochterzelle.
Contrasting Effects of Dissimilatory Iron(III) and Arsenic(V) Reduction on Arsenic Retention and Transport

Reduction of arsenate As(V) and As-bearing Fe (hydr)- oxides have been proposed as dominant pathways of As release within soils and aquifers. Here we examine As elution from columns loaded with ferrihydrite-coated sand presorbed with As(V) or As(III) at circumneutral pH upon Fe and/or As reduction; biotic stimulated reduction is then compared to abiotic elution. Columns were inoculated with Shewanella putrefaciens strain CN-32 or Sulfurospirillum barnesii strain SES-3, organisms capable of As (V) and Fe (III) reduction, or Bacillus benzoevorans strain HT-1, an organism capable of As(V) but not Fe(III) reduction. On the basis of equal surface coverages, As(III) elution from abiotic columns exceeded As(V) elution by a factor of 2; thus, As(III) is more readily released from ferrihydrite under the imposed reaction conditions. Biologically mediated Asreduction induced by B. benzoevorans enhances the release of total As relative to As (V) under abiotic conditions. However, under Fe reducing conditions invoked by either S. barnesii or S. putrefaciens, approximately three times more As (V or III) was retained within column solids relative to the abiotic experiments, despite appreciable decreases in surface area due to biotransformation of solid phases. Enhanced As sequestration upon ferrihydrite reduction is consistent with adsorption or incorporation of As into biotransformed solids. Our observations indicate that As retention and release from Fe (hydr)oxide(s) is controlled by complex pathways of Fe biotransformation and that reductive dissolution of As-bearing ferrihydrite can promote As sequestration rather than desorption under conditions examined here.
Sol−Gel-Encapsulated Heme Proteins. Evidence for CO2 Adducts

Heme proteins have been the subjects of numerous studies of photoinduced ligand dissociation and recombination (e.g., O2, CO, and NO). Much of this work1 is aimed at unraveling the dynamical behavior of myoglobin (Mb), which lacks a crystallographic channel connecting the iron center with the solvent. Despite its importance as a conspicuous metabolic breakdown product, CO2 interactions with metalloproteins are not well understood. CO2 is required for the assembly of the active sites of some multinuclear metalloproteins (e.g., the Ni2 center of urease2). In carbonic anhydrase, zinc-coordinated hydroxide is believed3 to attack CO2, forming a bicarbonate product complex. Deoxyhemoglobin forms carbaminohemoglobin4 in red blood cells upon reaction of CO2 with the amino termini more readily than oxyhemoglobin does; oxygenation in the lungs causes CO2 release. More importantly, there is no direct evidence for the existence of a metal-ligated CO2 adduct of any metalloprotein. In addition to transporting gases, hemoglobin and myoglobin possess enzymatic activity: reactions of the met forms with peroxides generate intermediates5,6 containing ferryl (FeIVdO) and protein radical species that are capable of oxidizing small substrates. In the case of linoleic acid, it has been established7 that substrate oxidation by Mb occurs by direct ferryl oxygen atom transfer. In this paper, we demonstrate that ferrylMb oxidizes carbon monoxide to produce CO2. In addition, we present the first spectroscopic evidence for Fe-CO2 coordination in heme proteins. The reaction7 of metMb with excess hydrogen peroxide generates a metastable intermediate, containing ferryl iron, that decays within minutes to produce degraded forms of myoglobin. However, in a saturated CO solution, Mb is observed8 to produce a gaseous product. Table 1 presents the results of mass spectrometric analyses9 of the gases in sealed pear flasks containing combinations of metMb, H2O2, and CO in phosphate buffer (50 mM, pH 7.0). The m/e ) 44 signal clearly indicates that the product of the catalyzed reaction is CO2. However, the low solubility of CO2 precluded attempts to obtain the electronic spectrum of the product complex under these conditions. Following the suggestion of Ibers10 that liquid CO2 be used in searching for new CO2 complexes, we reasoned that supercritical CO2 would be an even better choice, owing to its gaslike viscosity. Furthermore, supercritical fluids constitute reaction media that are of emerging biotechnological interest.11
Web crippling and combined bending and web crippling of cold-formed steel beam headers

Beam headers are commonly used in walls framed with cold-formed steel studs to span openings in bearing walls. This paper presents the results of an experimental study conducted at the University of Missouri-Rolla to establish the web crippling strength of both box- and I-beam headers for an interior-one-flange (IOF) loading condition. The beam header specimens were tested as a system consisting of two C-sections together with top and bottom track sections. The header configuration used in this study are defined in the Standard for Cold-Formed Steel Framing, Header Design (2000). Tested as a system, it was found that the web crippling strength was greater than that for two independent, single web C-sections. Based on the results of this study design recommendations are proposed.
Cysts of the semilunar cartilage

Abstract In this article I have essayed to give an analysis of the location, age group, signs, symptoms and pathology of cysts of the semiluncar cartilages. Extirpation of the cyst with the meniscus will effect a cure. This type of cyst probably arises in a traumatized area in the capsular border of the cartilage, which undergoes mucoid degeneration and cyst formation. The cysts are ganglions of the menisci.
Uptake of lead and arsenic in food plants grown in contaminated soil from Barber Orchard, NC

Abstract Elevated levels of heavy metals in soil may allow uptake of these toxic species in food plants. Barber Orchard, Haywood County, NC has been designated a U.S. EPA Superfund site, primarily because of elevated levels of lead and arsenic. In this work, carrots, lettuce, and tomatoes were cultivated in a greenhouse in control soil and soil obtained from Barber Orchard. The resulting samples were then analyzed for lead and arsenic using inductively coupled plasma optical emission spectrometry (ICP–OES). Except for carrot roots grown in the contaminated soil, the concentrations of lead and arsenic in the plants were below the ICP-OES detection limit. The concentration of lead in carrot roots was 20 ± 11 μg/g, which represents a bioconcentration factor (BCF) of 0.03.
Toward shared decision making at the end of life in intensive care units: opportunities for improvement.

Background In North America, families generally wish to be involved in end-of-life decisions when the patient cannot participate, yet little is known about the extent to which shared decision making occurs in intensive care units. Methods We audiotaped 51 physician-family conferences about major end-of-life treatment decisions at 4 hospitals from August 1, 2000, to July 31, 2002. We measured shared decision making using a previously validated instrument to assess the following 10 elements: discussing the nature of the decision, describing treatment alternatives, discussing the pros and cons of the choices, discussing uncertainty, assessing family understanding, eliciting patient values and preferences, discussing the family's role in decision making, assessing the need for input from others, exploring the context of the decision, and eliciting the family's opinion about the treatment decision. We used a mixed-effects regression model to determine predictors of shared decision making and to evaluate whether higher levels of shared decision making were associated with greater family satisfaction. Results Only 2% (1/51) of decisions met all 10 criteria for shared decision making. The most frequently addressed elements were the nature of the decision (100%) and the context of the decision to be made (92%). The least frequently addressed elements were the family's role in decision making (31%) and an assessment of the family's understanding of the decision (25%). In multivariate analysis, lower family educational level was associated with less shared decision making (partial correlation coefficient, 0.34; standardized beta, .3; P = .02). Higher levels of shared decision making were associated with greater family satisfaction with communication (partial correlation coefficient, 0.15; standardized beta, .09; P = .03). Conclusions Shared decision making about end-of-life treatment choices was often incomplete, especially among less educated families. Higher levels of shared decision making were associated with greater family satisfaction. Shared decision making may be an important area for quality improvement in intensive care units.
In vitro stability study of organosilane self-assemble monolayers and multilayers

The stability of self-assembled monolayers (SAMs) and multilayers formed on silicon surface by amino-terminated silanes and SAMs formed by alkyl and glycidyl terminated silanes were investigated in vitro with saline solution at 37 degrees C for up to 10 days. FTIR and XPS results indicated that amino-terminated SAMs and multilayers are very unstable if the alkyl chain is short ((CH2)3), while stable if the alkyl chain is long ((CH2)11). On the other hand, alkyl-terminated SAMs are very stable regardless of the alkyl chain length, and glycidyl terminated SAM retained approximately 77% of the organosilane molecules after 10 days. Hydrogen bonding between the organosilane monomer and silicon surface and among the organosilane monomers is believed to contribute to the instability of the SAM and multilayer formed by amino-terminated silane with a short alkyl chain ((CH2)3). Therefore, the widely used (3-aminopropyl) trimethoxysilane (APTMS) SAM and multilayer may not be suitable for implantable biomedical applications.
Serum concentrations of ergovaline/ergot alkaloids in late-term pregnant mares grazing endophyte-infected tall fescue pastures: A preliminary report

s / Theriogenology 70 (2008) 576–591 583 4500 treatment group (NC = 100.0 0.0%, 400 = 54.4 8.6%, 900 = 75.0 7.1%, and 4500 = 97.9 2.8%; P < 0.05). Centrifugation at 400 or 900 g did not damage equine sperm. Further studies of centrifugation forces between 900 and 4500 g are warranted to find optimal forces that maximize recovery rate, minimize sperm damage and do not affect fertility.
Building an Institution Second to None: Dr. Inabel Burns Lindsay—A Social Work Leader in the Academy

This article describes Dr. Inabel Burns Lindsay's leadership as the founding dean at Howard University School of Social Work during her 30 years of service from 1937 to 1967. It chronicles her efforts to build the School as well as her efforts to highlight social injustices of the time. Her lifelong efforts promoted the inclusion of African American social workers in the workforce and the need to understand sociocultural factors in working with different ethnic and racial groups. As a female dean, Dr. Lindsay was an avid promoter of social justice and a prolific writer and speaker on the topic. This article introduces the reader to this under-recognized social work pioneer, with emphases on the challenges of her time and her leadership style.
Synaptic organization in the dorsal cochlear nucleus of the cat: A light and electron microscopic study†

This report describes some observations of the synaptic organization of one region of the cat dorsal cochlear nucleus (DCN). The large “fusiform cell” and its innervation from the cochlea are emphasized. The morphology of the mature fusiform cell and its postnatal development are described in rapid Golgi impregnations of perfusion-fixed littermate cats. The mature features are correlated with profiles of fusiform cell bodies, apical dendrites, and basal dendritic trunks in electron micrographs from adult cat brains. Small neurons and granule cells are also identified in electron micrographs. In Golgi impregnations, axons of small cells and granule cells may terminate upon fusiform cells. Six classes of axons can be distinguished in rapid Golgi impregnations of the DCN. Two classes are of cochlear origin. One axonal class arises from small cells. The sources of the remaining axonal classes have not been identified in this study. Primary afferents can terminate as large, mossy endings in the DCN neuropil. They can also participate in axonal nests along with axons and dendrites of small cells. In electron micrographs, four synaptic endings can be distinguished. Primary cochlear fibers end in large terminals with asymmetrical synaptic complexes and round, clear vesicles. Primary axons can end in glomeruli, resembling those of the cerebellum, or in synaptic nests which are conglomerates of neuronal processes including other types of endings. The origins of the other synaptic types are not yet known. According to this study, primary afferent input could influence fusiform cells directly or indirectly, via small cells and granule cells.
Efficient computation of the 2-D Green's function for 1-D periodic structures using the Ewald method

The Ewald method is applied to accelerate the evaluation of the Green's function of an infinite periodic phased array of line sources. The Ewald representation for a cylindrical wave is obtained from the known representation for the spherical wave, and a systematic general procedure is applied to extend previous results. Only a few terms are needed to evaluate Ewald sums, which are cast in terms of error functions and exponential integrals, to high accuracy. Singularities and convergence rates are analyzed, and a recipe for selecting the Ewald splitting parameter /spl epsiv/ is given to handle both low and high frequency ranges. Indeed, it is shown analytically that the choice of the standard optimal splitting parameter /spl epsiv//sub 0/ will cause overflow errors at high frequencies. Numerical examples illustrate the results and the sensitivity of the Ewald representation to the splitting parameter /spl epsiv/.
Growth of Epitaxial BaTiO3 Thin Films at 600°C by Metalorganic Chemical Vapor Deposition

Presented at Ferroelectric thin films IV : symposium held November 29-December 2, 1994, Boston, Massachusetts, U.S.A.
The evolving group: towards a prescriptive theory of intentional group development

Purpose – The purpose of this paper is to provide a theoretical framework for understanding and formulating team intentional change.Design/methodology/approach – Based on a critical review of existing theories of group development, gaps in the literature regarding how teams can and should develop, especially when the change is intentional and has a desired direction, are examined. A set of propositions is offered to address these aspects of group development that have been neglected by the literature.Findings – A systematic and critical discussion of the core literature on group development showed: the complex and discontinuous nature of change in groups was neglected, because the group was not treated as a complex system; the literature has not dealt with group development processes when the change process is intentional (it has been descriptive of what occurs), nor has it examined which are key drivers of group change; existing literature on group development have predominantly seen negative emotion as ...
Effects of phorbol esters and calcium ionophore on nonspecific cytotoxic cells

Abstract In the present study mechanisms of signal transduction were investigated by treatment of NCC with phorbol esters and calcium ionophore. NCC were stimulated to produce 3-fold increased cytotoxicity by 10 −4 to 10 −5 M A23187. PMA, PDD, and 4-beta phorbol either suppressed NCC lysis (PMA) or had no enhancing effects (PDD and 4-beta). At a concentration of 10 −4 M increased cytotoxicity occurred after 0.5 to 3 hours treatment. Four-hour preincubation enhanced cytotoxicity at suboptimal A23187 concentrations. A23187 produced increased NCC activity at each E:T ratio tested, however, greatest differences in A23187 concentrations were observed at 20:1 and 40:1. The effects of simultaneous treatment of NCC and/or sequential with PMA and A23187 indicated that different transduction pathways might operate to augment cytotoxicity. PMA, 10 −8 M, combined with 10 −4 M concentrations of A23187 produced a 164.7% increase in cytotoxicity compared to media controls, and a 37.7% increase compared to A23187 controls. These data indicate that teleost cytotoxic cells, unlike mammalian NK, are augmentable by increased levels of extracellular calcium without the presence of any other comodulating signals.
Rapid exhumation of ice-covered rocks of the Chugach–St. Elias orogen, Southeast Alaska

6yr) using low-temperature thermochronometers is challenged by thick ice cover that restricts sampling to the remote mountain ridges that tower over the massive glaciers. However, the glaciers act as conveyor belts, and they transport material exhumed below the glaciers to the fl anks of the orogen. Our strategy is to examine sediments from glacial rivers for insights into how exhumation has proceeded beneath the otherwise inaccessible ice cover. This study provides the fi rst insight into the exhumation history of the Chugach–St. Elias orogen as it is recorded by detrital zircon fi ssion track and U/Pb ages. Our results differ signifi cantly from bedrock studies and refl ect the disparity of cooling ages exposed in valleys (glacial river) and ridges (bedrock).
Zircaloy-2 lined zirconium barrier fuel cladding

The introduction of Zr-lined barrier fuel clad tubing by GE in the early 1980s to counter the pellet-clad interaction (PCI) failure mechanism in fuel for boiling water reactors provided a major improvement in fuel reliability and operational flexibility. While the frequency of fuel failures has been substantially reduced in the past decade, an increased tendency has been observed for failed fuel rods to exhibit post-failure degradation in the form of longer cracks that allow release of radioactive off-gas and contamination of the reactor coolant circuit with tramp fuel material. One factor involved in this degradation is hydriding of the cladding at a location remote from the initial perforation of the fuel rod. This local hydriding can lead to a secondary crack initiation in the cladding when stressed by the fuel expansion accompanying a power increase. A modification of Zr-lined barrier fuel clad tubing has been developed to retard post-failure local hydriding while retaining the proven PCI resistance of the high-purity sponge Zr barrier. By adding a thin inner layer of corrosion-resistant Zircaloy-2 bonded to the inner surface of the Zr-barrier tube, the resistance to internal corrosion and hydrogen generation in a perforated fuel cladding tube is made equivalent to thatmore » of an all-Zircaloy-2 tube. Tests show that the PCI mitigating capability of the Zr barrier. By adding a thin layer of corrosion-resistant Zircaloy-2 bonded to the inner surface of the Zr-barrier tube, the resistance to internal corrosion and hydrogen generation in a perforated fuel cladding tube is made equivalent to that of an all-Zircaloy-2 tube. Tests show that the PCI mitigating capability of the Zr barrier is not compromised by this inner Zircaloy-2 liner. Materials considerations and manufacturing technology used to integrate this optional inner liner with other Zr barrier tubing properties and performance requirements are discussed with a summary of testing experience.« less
Discriminant validity with a direct observational assessment system: Research with previously identified groups

AbstractBased on a study of 40 school-age children (20 identified as “language disordered” and 20 as “normal language users”), the discriminant validity of a direct observational assessment system is investigated. Results indicate strong discriminant validity on most of the measurement parameters of this tool, Systematic Observation of Communicative Interaction. Discussion of the implications of these findings is provided.
Surflex-Dock 2.1: Robust performance from ligand energetic modeling, ring flexibility, and knowledge-based search

The Surflex flexible molecular docking method has been generalized and extended in two primary areas related to the search component of docking. First, incorporation of a small-molecule force-field extends the search into Cartesian coordinates constrained by internal ligand energetics. Whereas previous versions searched only the alignment and acyclic torsional space of the ligand, the new approach supports dynamic ring flexibility and all-atom optimization of docked ligand poses. Second, knowledge of well established molecular interactions between ligand fragments and a target protein can be directly exploited to guide the search process. This offers advantages in some cases over the search strategy where ligand alignment is guided solely by a “protomol” (a pre-computed molecular representation of an idealized ligand). Results are presented on both docking accuracy and screening utility using multiple publicly available benchmark data sets that place Surflex’s performance in the context of other molecular docking methods. In terms of docking accuracy, Surflex-Dock 2.1 performs as well as the best available methods. In the area of screening utility, Surflex’s performance is extremely robust, and it is clearly superior to other methods within the set of cases for which comparative data are available, with roughly double the screening enrichment performance.
Disk drive read channel design in advanced sub-micron CMOS

This paper reviews the migration of read channels from analog peak-detect architectures in biCMOS to digital PRML architectures on advanced sub-micron CMOS. It has identified some of the challenges the analog designer faces when using advanced sub-micron CMOS for high-performance analog circuit design.
SOURCES OF CO2 EMISSION FROM A NORTHERN PEATLAND: ROOT RESPIRATION, EXUDATION, AND DECOMPOSITION

Northern peatlands are substantial sinks of carbon (C), yet the sources of carbon dioxide (CO2) emitted from peatlands are largely unknown. Since the relationship between roots and peat in C cycling is important, vascular plants growing on the surface of peat deposits should influence CO2 efflux from the peat surface and the overall C balance in peatlands. In our study, 30-cm peat cores were removed from an ombrotrophic bog in boreal, continental western Canada. Surface vegetation in the cores remained intact and included a continuous bryophyte cover dominated by Sphagnum fuscum. In addition, some cores were collected such that either ericaceous shrubs (Ledum groenlandicum) or sedges (Eriophorum vaginatum) were present. We investigated how the presence of each vegetation type influenced soil respiration and the microbial mineralization of root exudates using a pulse 14C labeling of vegetation in the intact peat cores. The role of root biomass and root respiration in CO2 emission and C allocation was quantified for each type of vegetation and compared through both measurement and modeling. Our results show that vascular plants contributed 35-57% of total CO2 efflux from the peat surface, primarily derived from rhizosphere processes, including root respiration as well as microbial mineralization of root exudates. The mineralization of root exudates contributed 14-53 pmol C-CO2.m-2-d-' (17- 24% of total) to CO2 efflux, depending on vegetation type and moisture conditions. The type of vegetation present did not influence the total amount of photosynthetic fixation over the course of the study, but did affect how C was allocated within and between both the aboveground and belowground components of the peat column.
URINARY ORGANIC ACIDS FOUND IN B6‐DEFICIENT RATS AND CALCIUM OXALATE CALCULUS PATIENTS1

SUMMARY 1 B6-deficient rats and calcium oxalate stone-forming patients share several metabolic abnormalities. 2 In our experiments, evidence for folic acid deficiency in the stone patients is strong, and some evidence exists in B6–deficient rats as well. 3 Susceptibility to overload of the acetyl coenzyme A system is high in both. 4 Sources of oxalic acid probably include aromatic amino acid derivatives with a 3 carbon side chain, whose metabolism is blocked by tyrosine, and whose dependence on the acetyl coenzyme A system is shown by the simultaneous drop in oxalate, hippurate, α-ketoglutarate and citric acids. That hydroxy-proline is a major source seems a probable explanation for changes in oxalate excretion with stress. 5 Both B6–deficient rats and hyperoxaluric patients respond to tyrosine administration by a drop in urinary oxalate.
Musculoskeletal manifestations of mild osteogenesis imperfecta in the adult

The musculoskeletal manifestations of mild forms of osteogenesis imperfecta are not well defined in the adult. The aim of this study was to characterize the musculoskeletal manifestations and resulting impairments reported by adults with mild osteogenesis imperfecta. For this task a survey of musculoskeletal symptoms and impairments was hosted on the Osteogenesis Imperfecta Foundation web site for 6 weeks. Survey responses are reported herein. There were 111 unduplicated, adult respondents (78 female). Mean age was 40.8 years. More than one-quarter of 3,410 lifetime fractures occurred in adulthood. Nearly half of respondents reported an established diagnosis of “arthritis” (usually osteoarthritis), and the majority of these reported some degree of impairment attributable to arthritis. Articular pain, stiffness and instability were dominant in the large, weight-bearing joints of the lower extremities. Back pain and scoliosis were common. Of the respondents, 15% required assistance with light physical tasks and personal care. Two-thirds reported joint hyper-mobility, and one-third reported a previous tendon rupture. Complex regional pain syndrome was rare. Respondents reported frequent use of medications known to have potential adverse skeletal effects. In spite of these concerns the majority rated their overall physical health as good or excellent. Adults with mild osteogenesis imperfecta continue to sustain fractures into adulthood, and the majority reports some functional impairment due to musculoskeletal issues. Significant impairment is not rare.