cssi/SciSciGPT-SciSciNet huggingface dataset:
Finite length band-limited extrapolation of discrete signals

The problem of finite-length extrapolation of bandlimited sequences is formulated in terms of an energy minimization problem. Given a finite subset of samples (not necessarily consecutive) and a band limit omega /sub s/, it is shown how to find an extrapolated sequence that agrees with the given subset of samples and has the minimum energy within the band omega /sub s/ >
A 3-dimensional model for inductively coupled plasma etching reactors: coil generated plasma asymmetries

Summary form only given. Inductively coupled plasma (ICP) reactors are being developed as high plasma density (10/sup 11/-10/sup 12/ cm/sup -3/), low gas pressure (<10 s mTorr) sources for etching and deposition of semiconductor materials. Although ICP plasma etching tools have been developed which have a high degree of plasma uniformity, it is not uncommon to find azimuthal asymmetries and side-to-side variations in etch rates and plasma density. These asymmetries have been correlated with azimuthal variations in input and pumping of gases, circuit issues related to transmission line matching to the coil, and particulars of the reactor configuration. In this paper, we describe a 3-dimensional, time dependent model for ICP reactors whose intent is to provide an infrastructure to investigate asymmetries in plasma etching and deposition tools. The model is a 3-dimensional extension of a previously described 2-dimensional simulation called the hybrid plasma equipment model (HPEM). HPEM-3D consists of an electromagnetics module (EMM), a Boltzmann-electron energy module (BEM) and a fluid-chemical kinetics simulation (FKS). The inductively coupled electromagnetic fields are produced by the EMM. Those fields are used in the BEM to solve the electron energy equation using transport coefficients derived from solution of Boltzmann's equation, and fluxes obtained from the FKS. The electron energies and source functions obtained from the BEM are used in the FKS where the species densities are calculated and Poisson's equation is solved. The EMM includes a transmission line circuit model for the coil which accounts for azimuthal variations in the coil current.
Process variation monitoring (PVM) by wafer inspection tool as a complementary method to CD-SEM for mapping field CDU on advanced production devices

As design rules shrink, Critical Dimension Uniformity (CDU) and Line Edge Roughness (LER) have a dramatic effect on printed final lines and hence the need to control these parameters increases. Sources of CDU and LER variations include scanner auto-focus accuracy and stability, layer stack thickness, composition variations, and exposure variations. Process variations, in advanced VLSI production designs, specifically in memory devices, attributed to CDU and LER affect cell-to-cell parametric variations. These variations significantly impact device performance and die yield. Traditionally, measurements of LER are performed by CD-SEM or OCD metrology tools. Typically, these measurements require a relatively long time to set and cover only selected points of wafer area. In this paper we present the results of a collaborative work of the Process Diagnostic & Control Business Unit of Applied Materials and Hynix Semiconductor Inc. on the implementation of a complementary method to the CDSEM and OCD tools, to monitor defect density and post litho develop CDU and LER on production wafers. The method, referred to as Process Variation Monitoring (PVM) is based on measuring variations in the scattered light from periodic structures. The application is demonstrated using Applied Materials DUV bright field (BF) wafer inspection tool under optimized illumination and collection conditions. The UVisionTM has already passed a successful feasibility study on DRAM products with 66nm and 54nm design rules. The tool has shown high sensitivity to variations across an FEM wafer in both exposure and focus axes. In this article we show how PVM can help detection of Field to Field variations on DRAM wafers with 44nm design rule during normal production run. The complex die layout and the shrink in cell dimensions require high sensitivity to local variations within Dies or Fields. During normal scan of production wafers local Process variations are translated into GL (Grey Level) values, that later are grouped together to generate Process Variation Map and Field stack throughout the entire wafer.
Instrumentation for the Measurement of Inmates' Drug Use, Knowledge, and Attitudes

A methodology was devised for the construction of instruments to measure inmates' drug use, knowledge, and attitudes. A drug use inventory and a drug attitude scale were examined for construct validity, whereas a drug knowledge test was examined for content validity. In regard to reliability, each measurement tool was subjected to item analysis for internal consistency. Investigators obtained necessary data from 150 inmates at two county correctional institutions. Factors considered during instrumentation were subjects' reading and comprehension levels, drug experiences, and willingness to participate in data collection. Implications and suggestions are discussed concerning the use of such instruments in inmate drug education.
Studies on the mechanism of fatty acid synthesis II. Cofactor requirements of the soluble pigeon liver system

Abstract The synthesis of long-chain fatty acids from acetate by the reconstituted fractions of pigeon liver supernatant requires the following cofactors: ATP, CoA, GSH, DPNH, Mn++, isocitrate and TPN. Glucose- i -phosphate is needed in crude systems but this component can be replaced by DPNH in the more purified system. Isocitrate cannot be replaced by TPNH or a TPNH-generating system such as glucose-6-phosphate dehydrogenase system plus substrate. However, it can be replaced by a combination of α-ketoglutarate, CO2, and a TPNH generating system.
An assessment of overwinter food limitation in a snowshoe hare population at a cyclic low

Snowshoe hares (Lepus americanus) undergo 8- to 11-year population cycles caused by direct and/or interactive effects of overwinter food shortage and predation. However, the demographic significance of food shortage during cyclic population lows remains unclear. I evaluated the importance of overwinter food limitation to the demography (numbers, age and sex ratios) of low-density hare populations during two winters in Manitoba. Also, I examined whether the hypothesized differences in demography of fed and unfed hare populations could be explained by altered movement patterns or social dynamics. Bimonthly live-trapping revealed that food failed to have a direct long-term effect on the number, or change in number, of hares estimated to be on the three supplemented areas, relative to three control areas. Modest numerical responses to supplementation tended to be short-term (i.e., restricted to winter) and related to pre-supplementation densities, with the study area characterized by the highest hare density displaying the strongest and most consistent response to added food. During winter the percentage of females was remarkably variable among study areas and time periods, but added food may have augmented slightly the proportion of females captured in traps. There tended to be slightly more juveniles on supplemented areas during winter periods, and this effect was strongest during the first winter (1991–1992). I found that immigration rates and percentage of hares that were considered to be transient animals were similar on supplemented and control areas, and that spatial distribution of radio-collared animals on versus off of study areas also was similar. Because the overall effect of food on hare populations was small and short-lived, and could be explained largely by small increases in survival and reproduction, I conclude that the study population was not subject to overwinter food limitation.
Indirect Photometric and Fluorometric Detection in High-Performance Liquid Chromatography: A Tutorial Review

A review of indirect photometric and fluorometric detection in high-performance liquid chromatography (HPLC) is presented. A functional definition of indirect detection, somewhat broader and simpler than what was often used to characterize these techniques, was employed for this review. Emphasis was placed on distinguishing different approaches to indirect photometric and fluorometric detection in HPLC based on the interactions which occur between the analytes and the detectable components either within the column or postcolumn.
Real Gas Pseudopressures For CO2 Reservoirs

This paper presents a new method for correlating real gas pseudopressure values of gas reservoirs containing large amounts of CO/sub 2/. Special attention is devoted to gas reservoirs in Colorado, New Mexico, and Utah. These reservoirs have 95 to 100% CO/sub 2/ concentrations. The effects of CO/sub 2/ on the skin factor also are analyzed. The main results of this study are that (1) the effects of CO/sub 2/ on the conventional pressure analysis techniques are severe at higher mole fractions and at pseudoreduced pressures greater than one, (2) if real gas pseudopressure data are not properly corrected, the reservoir permeability calculated from pressure buildup and drawdown tests will be considerably less than the actual value, and (3) the proposed technique is simple, quick, and accurate enough to calculate pseudopressure values. This method is also useful in gas reservoirs with 0 to 100% CO/sub 2/ concentrations. CO/sub 2/ affects the skin zone both physically and chemically, in most cases favorably. The total skin factor is slightly dependent on time for very short transient flows. However, it ultimately will become constant as the CO/sub 2/ gas sweeps the entire skin zone.
EXPRESSION AND FUNCTIONAL ROLE OF E- AND P-CADHERINS IN MOUSE MAMMARY DUCTAL MORPHOGENESIS AND GROWTH

Mammary ducts, and the highly mitotic terminal end buds from which they are derived, consist of two layers of ectodermally derived epithelium, forming a tube-within-a-tube structure. We investigated the role of Ca2+-dependent cell-cell adhesion molecules in maintaining the integrity of these layers. Immunostaining showed abundant E-cadherin on the lateral membranes of end bud body cells and ductal lumenal cells, but no P-cadherin. The basally located cap cells and their differentiated descendants, the ductal myoepithelial cells, displayed only P-cadherin. We investigated the functional significance of this pattern of cadherin expression in situ by surgically implanting small, slow-release plastic implants releasing function-blocking antibodies. End buds exposed to a monoclonal antibody to E-cadherin showed disruption of the body epithelium, with epithelial cells floating freely in the lumen. Epithelial DNA synthesis, which is normally very high in these growth buds, abruptly declined. That this reduction in growth was not due to cell damage was shown by spontaneous reaggregation of the cells into a normal epithelium, with resumption of DNA synthesis, when the blocking antibody was depleted. A monoclonal antibody to P-cadherin had no effect on the lumenal layer but partially disrupted the basally located cap cell layer. These data indicate that spatially selective expression of E- and P-cadherins is required for mammary tissue integrity, which is in turn a prerequisite for normal rates of DNA synthesis.
Ammonia Control in Broiler Houses

Abstract Poultry litter on which one group of broiler chickens had been grown was treated with superphosphate and phosphoric acid to determine effectiveness of suppression of ammonia release from litter during brooding of chickens using the limited-area brooding concept. Phosphoric acid was effective in controlling ammonia release for the first 10 days of brooding. Superphosphate decreased ammonia release but did not control it. Very little ammonia was released when litter pH was below 7; release was rapid when pH was 8 or above.
Comparative endocrinology-paracrinology-autocrinology of human adult large vessel endothelial and smooth muscle cells.

Endothelial and smooth muscle cells were isolated from human adult large blood vessels to compare their proliferative response to hormones and growth factors. Neural extracts and the medium from differentiated hepatoma cells were used as concentrated sources of required hormones and growth factors that supported both cell types. Active hormones and growth factors were identified from the neural extracts and hepatoma medium by substitution or direct isolation and biochemical characterization. Epidermal growth factor, lipoproteins, and heparin-binding growth factors elicited growth-stimulatory effects on both endothelial and smooth muscle cells. Both types of human vascular cells displayed 7600 to 8600 specific heparin-binding growth factor receptors per cell with a similar apparent dissociation constant (Kd) of 200 to 250 pM. Heparin modified the response of both endothelial and smooth muscle cells to heparin-binding growth factors dependent on the type of heparin-binding growth factor and amount of heparinlike material present. In addition, heparin exerted a growth factor-independent inhibition of smooth muscle cell proliferation. Platelet-derived growth factor, insulinlike growth factors, and glucocorticoid specifically supported proliferation of smooth muscle cells with no apparent effect on endothelial cell proliferation. Growth-factorlike proteinase inhibitors had an impact specifically on endothelial cell proliferation. Transforming growth factor beta was a specific inhibitor of endothelial cells, but had a positive effect on smooth muscle cell proliferation. The results provide a framework for differential control of the two vascular cell types at normal and atherosclerotic blood vessel sites by the balance among positive and negative effectors of endocrine, paracrine and autocrine origin.
“We Learn How to Predict and be a Scientist”: Early Science Experiences and Kindergarten Children's Social Meanings About Science

We examine kindergarten children's emerging social meanings about science as a function of their participation in integrated science inquiry and literacy activities associated with the Scientific Literacy Project (SLP). We describe changes in 123 SLP kindergarten children's narrative accounts of learning science in school during three different time periods: (a) in September, before the onset of SLP activities; (b) in December, after children had participated in 17 lessons associated with 4 SLP units; and (c) in March, after children had participated in an additional 13 lessons associated with the SLP Marine Life unit. At the end of the year, we: (a) compare SLP children's narratives about science to those of a group of children (n = 70) who only experienced the regular kindergarten program; and (b) examine differences between SLP and comparison children's reports on a measure of learning activities in kindergarten that include science as well as privileged content areas such as reading, writing, and lear...
Spectroscopic and enzymatic characterization of the active site dinuclear metal center of calcineurin: implications for a mechanistic role

The active site of bovine brain calcineurin contains an Fe3+-Zn2+ dinuclear metal center. Replacement of Zn2+ with Fe2+ yields a mixed valence Fe3+-Fe2+ center that exhibits a characteristic EPR signal that can be used as a convenient spectroscopic probe of the active site. Addition of product phosphate to both the Fe3+-Fe2+ and Fe3+-Zn2+ forms of calcineurin led to perturbations of the respective EPR signals, indicating that phosphate affects the environment of the paramagnetic centers. Anaerobic titrations of the iron-substituted Fe3+-Fe2+ enzyme with dithionite resulted in a gradual loss of activity toward pNPP that paralleled the loss of intensity of the EPR signal of the mixed valence diiron center. During dithionite reduction, an EPR resonance with g approximately 12 appeared. The intensity of this resonance increased when the spectrum was recorded in a parallel mode cavity and was therefore attributed to a paramagnetic center with integer spin. Oxidation of the Fe3+-Fe2+ cluster to the diferric state by hydrogen peroxide also led to a loss of activity. These results indicate that the mixed valence oxidation state represents the catalytically competent form of the cluster. The dependence of the enzyme activity on the redox state of the cluster has implications for a mechanistic role.
Impaired Strategic Monitoring as the Locus of a Focal Prospective Memory Deficit

In this study we examine the locus of a prospective memory deficit in an individual with multiple sclerosis. Extensive psychometric and neuropsychological testing revealed above average to superior general intelligence, retrospective and autobiographical memory, short-term/working memory and executive functions. In contrast, the individual demonstrated poor prospective memory on a variety of measures incorporating naturalistic, self-report, and laboratory methods. This deficit appeared to arise from a disruption of processes underlying strategic monitoring. These data clearly demonstrate that impaired prospective memory can exist in the presence of an otherwise intact neuropsychological profile.
Narrating hyphenated selves: Intergroup contact and configurations of identity among young Palestinian citizens of Israel

Abstract Contemporary Palestinian citizens of Israel must negotiate disparate identities as they construct a “hyphenated” self. Their status as a national indigenous minority places them in a particular location of subordination and existential insecurity within Israeli society, which has been accentuated during the intensification of conflict between Israel and the Palestinians in the occupied territories since 2000. This study examines processes of identity negotiation and reconciliation in the personal narratives of young Palestinian citizens of Israel who participate in intergroup contact with Jewish Israelis and Palestinians from the occupied territories. An interpretive thematic analysis of personal narratives reveals the discursive strategies youth employ as they traverse the limits of hyphenation, constructing configurations of identity that reconcile conflicting discourses. Pre-contact narratives suggested considerable variability in processes of identity negotiation. Post-contact narratives were characterized by three patterns: (1) Palestinian identity accentuation, in which youth came to identify more strongly with their Palestinian national identity over their Israeli civic identity; (2) temporal stability, in which youth whose pre-contact narrative was already characterized by Palestinian identity accentuation maintained that configuration; and (3) life at the hyphen, in which youth actively struggled with and vacillated between states of conflict and integration of their disparate identities.
Abacavir pharmacogenetics--from initial reports to standard of care

Abacavir is a nucleoside analogue reverse transcriptase inhibitor indicated for the treatment of human immunodeficiency virus infection as part of a multidrug, highly active antiretroviral therapy regimen. Despite its efficacy, approximately 5% of individuals who receive abacavir develop an immune-mediated hypersensitivity reaction (HSR) that warrants immediate discontinuation of abacavir and switching to an alternative antiretroviral regimen. Abacavir HSR is associated with individuals who carry the *57:01 variant in the human leukocyte antigen B (HLA-B) gene. There is a large volume of evidence to show that those who carry HLA-B*57:01 are at significantly increased risk of developing HSR and should not receive abacavir. Pharmacogenetic screening to ensure individuals who carry HLA-B*57:01 do not receive abacavir can reduce the incidence of HSR and is now considered the standard of care before prescribing abacavir. Genetic testing to prevent abacavir HSR is currently one of the best examples of integrating pharmacogenetic testing into clinical practice.
The role of the kidneys in mevalonate metabolism fact and artifact

Abstract This laboratory has previously demonstrated that circulating mevalonate is metabolized primarily by the kidneys by both the sterol and nonsterol pathways of mevalonate metabolism. Bardenheier and Popjak recently challenged this conclusion, claiming that a contaminant in commercially obtained [5-14C]mevalonate can artifactually account for much of the 14C reported as 14CO2 in such experiments. In the present study, this contaminant was shown to occur at levels averaging only 0.08% and even if not corrected for, would cause less than a 4% error in calculating renal mevalonate oxidation. Further, regardless of the minor degree of contamination of commercial 14C-mevalonate, the kidney oxidized mevalonate to CO2 at rates averaging 24 times that of the liver. Finally, purified (R)-[5-14C]mevalonate was shown to yield results virtually identical, both in vitro and in vivo, to those obtained with commercial [5-14C]mevalonate. These data, therefore, fully confirm our previous conclusion that the kidney represents the primary organ site of mevalonate metabolism by the nonsterol, or shunt, pathway.
Radiation Dose Concerns for the Pregnant or Lactating Patient

Abstract This article discusses issues regarding administration of radiopharmaceuticals to pregnant women or nursing mothers. Uncertainties in calculated dose estimates and possible biological effects on the unborn child are presented. Models and dose estimates for pregnant women at several stages of gestation are given; the radionuclide of highest concern is 131 I-NaI due to its affinity for the fetal thyroid and the potentially high fetal thyroid doses. The article also reviews the extant literature regarding the expression of radiopharmaceuticals in breast milk, and suggested time periods for interruption of breast feeding after a nursing mother receives a radiopharmaceutical, if needed. Again, 131 I-NaI is often the radiopharmaceutical of most concern, for the same reasons in the nursing infant as were shown for the unborn child. Strategies for preventing unwanted administrations of radiopharmaceuticals to these patients are reviewed, with strategies for minimizing radiation doses where possible.
Assessment of monoamine transporter inhibition in the mediation of cocaine-induced conditioned taste aversion

Although the mechanisms of cocaine reward have been well characterized, the pharmacological basis of cocaine's aversive effects is less understood. Using the conditioned taste aversion (CTA) preparation, the present study examined the role of monoamine uptake inhibition in cocaine's aversive effects by comparing cocaine to three reuptake inhibitors with relative specificity for the transporters of dopamine (DAT; GBR 12909), norepinephrine (NET; desipramine) and serotonin (SERT; clomipramine). Specifically, 104 male Sprague-Dawley rats were given 20-min access to a novel saccharin solution followed immediately by a subcutaneous injection of cocaine, GBR 12909, desipramine, clomipramine (each at 18, 32 or 50 mg/kg; 12 groups) or drug vehicle (equivolume to the highest cocaine dose). Over trials, cocaine and desipramine each dose-dependently suppressed saccharin consumption and did so in an equivalent manner when matched by dose. However, both GBR 12909 and clomipramine conditioned weaker aversions than cocaine at the two lowest doses (18 and 32 mg/kg). At the highest dose (50 mg/kg), GBR 12909 produced equivalent suppression of saccharin consumption to cocaine while clomipramine's conditioned suppression remained relatively weak at this dose. These results suggest that cocaine's adrenergic actions resulting from NET inhibition may play a more significant role in the mediation of its aversive effects than its actions at DAT and SERT.
Across-critical-band processing of amplitude-modulated tones.

Two experiments using two‐tone sinusoidally amplitude‐modulated stimuli were conducted to assess cross‐channel effects in processing low‐frequency amplitude modulation. In experiment I, listeners were asked to discriminate between two sets of two‐tone amplitude‐modulated complexes. In one set, the modulation phase of the lower frequency carrier tone was different from that of the upper frequency carrier tone. In the other stimulus set, both amplitude‐modulated carriers had the same modulator phase. The amount of phase shift required to discriminate between the two stimulus sets was determined as a function of the separation between the two carriers, modulation depth, and modulation frequency. Listeners could discriminate a 50°–60° phase shift between the modulated envelopes for tones separated by more than a critical band. In experiment II, the modulation depth required to detect modulation of a probe carrier was measured in the presence of an amplitude‐modulated masker. The threshold for detecting probe modulation was determined as a function of the separation between the masker and probe carriers, the phase difference between the masker and probe modulators, and masker modulation depth (in all conditions, the rate of probe and masker modulation was 10 Hz). The threshold for detecting probe modulation was raised substantially when the masker tone was also modulated. The results are consistent with theories suggesting that amplitude modulation helps form auditory objects from complex sound fields.
The structure of the apolipophorin-III gene from Manduca sexta.

The sequence of the gene for apolipophorin-III from the tobacco hornworm, Manduca sexta, has been determined. The gene contains four exons: exon 1 contains a relatively short 5′ untranslated region and the first 15 amino acids of the signal sequence; exon 2 contains the remaining 3 amino acids of the signal sequence, the 5 amino acids of the pro sequence and residues 1–64 of the mature protein; exon 3 codes for residues 65–118 of the mature protein; and exon 4 codes for residues 119–165 of the protein plus the 3′ untranslated sequences. The apolipophorin-III gene differs from most vertebrate apolipoprotein genes in lacking an exon in the 5′ untranslated region and by the fact that the coding sequences are contained in 3, not 2, exons. A putative ecdysone receptor binding site is found approx. 110 nucleotides upstream from the transcription start site.
The science and ethics of placebo in pediatric psychopharmacology

Pediatric psychopharmacology is a relatively new science. Although the use of psychotropic medications in children has risen in the past decade, there are few standard treatments for serious psychiatric or developmental disorders of childhood. The relative absence of standard treatments is further complicated by the fact that many of the agents used in pediatric psychopharmacology have been adapted from other fields. Therefore, investigators have a responsibility to make incremental progress from concept through pilot studies and large-scale, multisite efficacy and safety trials. Thus, although there is a pressing need to conduct medication trials that can guide clinical practice, there are scientific and ethical considerations to bear in mind when designing clinical trials in pediatric psychopharmacology. This article reviews essential ethical and scientific issues that are relevant to designing clinical trials in children with psychiatric and developmental disorders. Using examples from recently publish...
A chelating gel for collection of copper from seawater

Abstract An affinity Chromatographic gel is coupled to carboxymethyl(imino)-bis(ethyl-enenitrilo) tetraacetic acid (DTPA) by a carbodiimide reaction. This gel is successful in extracting copper from seawater with high selectivity over alkaline earths such as mag-nesium. It is useful over a wide range of pH (4–9), and is stable and reversible over a period of nine months. Up to 20 μmol of copper can be adsorbed and recovered with greater than 99% efficiency with gel—DTPA prepared from 1 g of dry gel.
The Effects of Electromagnetic Vibration on Macrosegregation in AZ80 Magnesium Alloy Billets

The effects of electromagnetic vibration on macrosegregation in AZ80 magnesium alloy billets have been investigated experimentally. Comparing to conventional direct-chill casting, the enrichment for the alloying elements close to the billet surface is significantly reduced by the electromagnetic vibration. Increasing the stationary magnetic field, i.e., increasing the intensity of the electromagnetic vibration results in uniform distributions of the metallic elements in the billet. The distribution of impurity iron has the same tendency with alloying element manganese with and without the electromagnetic vibration. The uniformity in the concentration profile of iron is higher than that for the alloying elements in the billet and increases with increasing the stationary magnetic field of the system used for generation of electromagnetic vibration.
The impact on treatment planning of MRI of the spine in patients suspected of vertebral metastasis: An efficacy study

Abstract The objective of this study was to determine the efficacy of spinal MRI in suspected spinal metastasis. The effect of spinal MRI on treatment planning choices (radiation, chemotherapy, steroids, or surgery) in 130 patients with suspected spinal metastatic involvement was evaluated In a retrospective group of 100 patients, 47 (47%) had therapy changes associated with MR findings. Forty out of 78 (51%) of patients presenting with symptoms (back pain, weakness, paresthesia, or sphincter dysfunction) had MR associated therapy choices. Seven out of 22 (32%) of patients without spinal symptoms had therapy changes. Twelve out of 30 (40%) of patients evaluated prospectively had therapy choices directed by MR findings. Overall, 59 out of 130 (45%) of patients had therapy choices associated with findings in spinal MRI. MRI results influenced the addition or modification of radiation therapy treatment in 33% of the patients suspected of metastatic disease to the spine.
Ultrahigh-resolution, wide-field-of-view Cs optical filter for doubled Nd lasers

Abstract We report a simple theoretical model for the calculation of the dependence of filter quantum efficiency versus laser pump power in an atomic Cs vapor laser-excited optical filter. We present the calculations for Cs filter transition that can be used to detect the practical and important frequency-doubled Nd lasers. The results of these calculations show the filter's quantum efficiency versus the laser pump power. The laser pump powers required range from 0.7 to 15 mW per square centimeter of filter aperture.
Synthetic Control of the Diameter and Length of Single Crystal Semiconductor Nanowires

A general synthetic method has been developed to control both the diameter and the length of nanowires during growth. This approach exploits monodisperse nanocluster catalysts to define both the nanowire diameter and the initiation of nanowire elongation during growth by a vapor−liquid−solid mechanism. To demonstrate this new approach, crystalline indium phosphide (InP) nanowires have been synthesized using a laser catalytic growth (LCG) process combined with gold nanocluster catalysts. InP nanowires with nearly monodisperse diameters of 10, 20, and 30 nm were grown from nanocluster catalysts having diameters of 10, 20, and 30 nm, respectively. High-resolution transmission electron microscopy studies show that the InP nanowires prepared in this manner are single crystals with a [111] growth direction. In addition, studies of nanowire growth as a function of growth time have shown that nanowire length is directly proportional to growth time and have enabled the preparation of InP nanowires with narrow leng...
Cenozoic Crustaceans of the East and West Indies

This is an issue of Scripta Geologica from the Nationaal Naturhistorisch Museum, Leiden around a single theme concerning Cenozoic crustaceans edited by Stephen Donovan. The lead-off paper by Schweitzer, Feldmann, and Bonadio (2009) erects a new family of heterotreme Brachyura, Martinocarcinidae, for that old problematic species Martinocarcinus ikeae Bohm, 1922 from the Late Eocene of Java. The authors do a reasonable job of redescribing the species, comparing it to contemporaneous and modern families, and concluding the uniqueness of this form is yet another example of the blast of experimental morphologies at a time in the Eocene of maximal diversity in the Brachyura. This paper highlights anew the fact that understanding family level diversity (Ng et al., 2008) is rather incomplete without inclusion of fossil forms. Collins, Mitchell, and Donovan (2009) have a short paper describing a new species of Pleistocene grapsid from Jamaica, Sesarma primigenium. The material consists of assorted claw parts, and demonstrates the limits of what can be done with these kinds of fossils. Collins, Donovan, and Stemann (2009) review the crustacean fauna from a new Late Pleistocene locality in the Port Morant Formation. The bulk of the fauna consists of claws of thalassinidean and brachyuran decapods. A few barnacles are included. Not much is done with the material except to list and illustrate the species. The final paper by Collins, Portell, and Donovan (2009) presents a more synthetic treatment of Neogene decapods of the Caribbean. The authors offer a useful country-bycountry catalog of what is currently known, but this section is loaded with statements such as this one from page 75 concerning Venezuela: ‘‘Falconoplax kugleri Van Straelen, 1933, has characters in common with Falconoplax bicarinella Collins & Morris, 1976, an Eocene species from Barbados ... .’’ One is left wondering what are those characters, and why is it important to know this: is a phylogenetic connection hinted at, or a possible synonymy? It is all the more intriguing because the discussion lays out in tabular form a great deal of the catalog, except only a single Falconoplax is recorded from the Castilla Formation, Lower Miocene (the F. kugleri I suppose). This was a bit disconcerting until one realizes the F. bicarinella mentioned above is Eocene, and only Neogene material is the subject of the paper. We are getting only half of the picture. An Appendix by Collins formally describes several new taxa. There is a lot of information in this paper, and someday someone will make an interesting story of the evolution of Cenozoic crustaceans of the Caribbean, but that is only hinted at here, e.g., the similarity indexes of Table 5. I wish the authors had gone further. For those interested in the taxonomy and evolution of Cenozoic crustaceans, it will be useful to know this little packet of papers exists.
Modelling the impacts of subsurface drainage on surface runoff and sediment yield in the Le Sueur Watershed, Minnesota, USA

Abstract Tile drainage influences infiltration and surface runoff and is thus an important factor in the erosion process. Tile drainage reduces surface runoff, but questions abound on its influence on sediment transport through its dense network and into the stream network. The impact of subsurface tiling on upland erosion rates in the Le Sueur River watershed, USA, was assessed using the Water Erosion Prediction Project (WEPP) model. Six different scenarios of tile drainage with varying drainage coefficient and management type (no till and autumn mulch-till) were evaluated. The mean annual surface runoff depth, soil loss rate and sediment delivery ratio (SDR) for croplands, based on a 30-year simulation for the watershed with untiled autumn mulch-till (Scenario 1), were estimated to be 83.5 mm, 0.27 kg/m2 and 86.7%, respectively; on no-till management systems (Scenario 4), the respective results were 72.3 mm, 0.06 kg/m2 and 88.2%. Tile drains reduced surface runoff, soil loss and SDR estimates for Scenar...
Altered Gene Expression after Optic Nerve Transection: Reduced Neurofilament Expression as a General Response to Axonal Injury

Previous studies have shown that axonal injury (axotomy) in neurons of the mammalian peripheral nervous system (PNS) results in a recapitulation of the developmental program for cytoskeletal gene expression; these changes include the increased expression of a developmentally regulated isotype of beta-tubulin (class II) and reduced neurofilament (NF) expression. In the present study we examined the abundance of mRNAs encoding the low-molecular-weight NF protein (NF-L) and class II beta-tubulin in RNA purified from the retinae of newborn rats, from the retinae of adult rats at 2, 7, and 14 days after intracranial transection of the ipsilateral optic nerve, and from contralateral control retinae. In order to facilitate comparison with representative PNS neurons, parallel analyses were carried out in axotomized dorsal root ganglion (DRG) sensory neurons. Since NF-L and class II beta-tubulin are neuron-specific proteins, axotomy-induced alterations in the levels of retinal mRNAs encoding these proteins largely reflect corresponding changes in expression by retinal ganglion cell neurons. Comparison of retinal RNA from newborn and adult (70-day-old) animals demonstrated a postnatal increase in NF-L and a decline in class II beta-tubulin mRNAs comparable to those previously described in DRG neurons. Reductions in NF-L mRNA levels were noted in retina at 2, 7, and 14 days after axotomy and in DRG neurons at 7 and 14 days after axotomy. The abundance of class II beta-tubulin mRNAs increased after axotomy in DRG neurons, but not in retina.(ABSTRACT TRUNCATED AT 250 WORDS)
Medication nonadherence and the outcomes of patients with quiescent ulcerative colitis

Abstract Purpose We conducted a prospective study to determine the effects of nonadherence with mesalamine among patients with quiescent ulcerative colitis. Methods We followed a cohort of 99 consecutive patients who had ulcerative colitis in remission for more than 6 months and who were taking maintenance mesalamine. Medication adherence rates were calculated based on pharmacy records and a validated formula. Nonadherence was defined as refilling less than 80% of prescribed medication. Patients were followed prospectively and evaluated either in clinic or via telephone at 6, 12, and 24 months. The primary outcome was clinical recurrence of ulcerative colitis. Proportional hazards models were used to adjust for confounders. Results At 6 months, 12 patients (12%) had clinical recurrence of disease symptoms, all of whom were nonadherent with medication. At 12 months, 19 of 86 patients had recurrent disease, 13 (68%) of whom were nonadherent. Patients who were not adherent with medication had more than a fivefold greater risk of recurrence than adherent patients (hazard ratio=5.5; 95% confidence interval: 2.3 to 13; P Conclusion Nonadherence with medication increases the risk of clinical relapse among patients with quiescent ulcerative colitis. Future research should be directed at behavioral interventions to improve adherence.
Stability of increased adenoma detection at colonoscopy. Follow-up of an endoscopic quality improvement program-EQUIP-II.

Stability of Increased Adenoma Detection at Colonoscopy. Follow-Up of an Endoscopic Quality Improvement Program-EQUIP-II
Limit distributions for the maxima of stationary Gaussian processes

Abstract Let { X n } be a stationary Gaussian sequence with E{ X 0 } = 0, { X 2 0 } = 1 and E{ X 0 X n } = r n n Let c n = (2ln n ) built1 2 , b n = c n − 1 2 c -1 n ln(4π ln n ), and set M n = max 0 ⩽ k ⩽ n X k . A classical result for independent normal random variables is that P[c n (M n −b n )⩽x]→exp[-e -x ] as n → ∞ for all x. Berman has shown that (1) applies as well to dependent sequences provided r n ln n = o(1). Suppose now that { r n } is a convex correlation sequence satisfying r n = o(1), ( r n ln n ) -1 is monotone for large n and o(1). Then P[r n -1 2 (M n − (1−r n ) 1 2 b n )⩽x] → Ф(x) for all x, where Ф is the normal distribution function. While the normal can thus be viewed as a second natural limit distribution for { M n }, there are others. In particular, the limit distribution is given below when r n is (sufficiently close to) γ /ln n . We further exhibit a collection of limit distributions which can arise when r n decays to zero in a nonsmooth manner. Continuous parameter Gaussian processes are also considered. A modified version of (1) has been given by Pickands for some continuous processes which possess sufficient asymptotic independence properties. Under a weaker form of asymptotic independence, we obtain a version of (2).
Study of visual acuity during the ocular pursuit of moving test objects. I. Introduction.

Visual acuity may be measured during the voluntary ocular pursuit of moving test objects. This visual function has been referred to as dynamic visual acuity. The apparent movement of the test object is produced by rotating a mirror in the desired plane of pursuit by means of a wheel and disk type variable speed drive. The range of angular velocities utilized is 10°/ to 170°/sec at the nodal point of the tested eye. It is shown that visual acuity deteriorates markedly and significantly as the angular velocity of the test object is increased. It is shown further that the relationship between visual acuity and the angular velocity of the test object may be described satisfactorily by the semiempirical equation Y=a+bx3. It also is pointed out that individuals possessing similar static acuity may differ significantly in their dynamic acuity. The possible causes for the observed deterioration of acuity are discussed and it is concluded that imperfect pursuit movements of the eye result in a continued motion of the image on the retina. This motion results in reduced intensity contrast, which is a factor in producing loss in acuity.
Catalysts of Cooperation in System of Systems: The Role of Diversity and Network Structure

Cooperation and competition are critical aspects of complex systems that intrigue researchers and practitioners alike. Recently, there has been great interest in how structure affects these cooperative behaviors and how they evolve. In this paper, we utilize the methods of evolutionary game theory on graphs to develop a model of the structured evolution of adaptive agents. Rather than simple memoryless agents, we employ adaptive agents that take on a diverse set of strategies including the cooperative catalyst tit-for-tat (TFT) and its generous and suspicious variants. We also employ all-defect, unconditional cooperation, and random strategies. Agents use these strategies during their evolution in order to maximize their own relative fitness, measured by their performance in a repeated Prisoner's Dilemma game versus their structural neighbors. We test the model with a variety of regular graph structures with variable degree, randomness, and size. Our parallel-execution agent-based simulations show that each strategy evolves toward its own structural niche with suspicious TFT maintaining the highest survival rate over all structures. We also show that increases in network density make the TFT strategies even more dominant, and connectivity randomness encourages cooperation in sparse networks.
Linear chains and chain-like fractals from electrostatic heteroaggregation

The internal structure of materials prepared by aggregation of oppositely charged polystyrene spheres (electrostatic heteroaggregation) is investigated by static light scattering, optical microscopy, and Brownian dynamics simulation. Light scattering indicates ultralow mass fractal dimensions, as low as 1.2. Such low fractal dimensions, approaching the theoretical limit of a linear object, imply a chaining mechanism. Optical micrographs reveal linear chains with the particle charge alternating down the chains. Brownian dynamics simulation gives additional support for a chaining mechanism. For the polystyrene system (120-nm primary particle diameters), the fractal dimension is found to increase from 1.2 to 1.7 as the background electrolyte is increased. In terms of electrostatic screening, the results match those reported recently for larger polystyrene spheres. The low fractal dimensions appear to represent a crossover from linear chains to a structure of diffusion-limited aggregates; however, experiments under density-neutral conditions imply that sedimentation plays an important role in the formation of ultralow fractal dimensions. The practical implication is that microcomposites with a locally uniform distribution of starting materials and almost any degree of branching can be prepared from oppositely charged particles.
A surface-wave study of the Pacific Ocean basin

SUMMARY Group velocity dispersion data from Rayleigh waves is used to map the crustal and upper-mantle structure beneath the Pacific Ocean basin. Data from the Global Digital Seismic Network (GDSN) provides dispersion information of a broad period range (15–300 s) necessary to achieve adequate resolution down to the upper mantle. No a priori assumption on regionalization is made; a stochastic grid-inversion method is used instead that allows the extraction of pure-path dispersion data from mixed-path measurements. The pure-path grid size is 10°× 10°, and the entire Pacific Ocean basin is divided into more than 100 grids. The large number of wave paths used permits sufficient resolution in the process of pure-path decomposition. A second generalized inversion is applied to the pure-path dispersion data for each individual grid element, resulting in shear velocity as a function of depth. The combined output of the velocity-depth functions of all grid elements gives a three dimensional crustal and upper-mantle structure of the Pacific Ocean basin. This enables cross-sections and depth slicings of the region to be made down to a depth of 300 km. Results show a detailed picture on the lateral heterogeneity of the crustal and upper mantle. The average thickness of the oceanic crust is less than 10 km. A few regions in the ocean basin are identified as having a continent-like crust. A pronounced low-velocity zone with shear velocity below 4.3 km s-1 exists nearly everywhere in the depth range from 70 to 200 km. The depth and thickness of this low-velocity layer vary over the Pacific Ocean basin, but are in general conformance with the known surface tectonic picture. The lateral heterogeneity and the regional distribution of velocity variations provide good baseline data for quantitative discussions of an upper mantle flow pattern and the associated dynamic process.
Opsonins in the hepatic clearance of pneumococci

An in situ isolated, perfused rat liver system was used to evaluate various opsonins for hepatic trapping and killing of encapsulated, virulent, type 3 pneumococci. Pneumococci were rapidly trapped in the liver in the presence of all potential opsonins including Hanks balanced salt solution with added colloid. However, with some of the potential opsonins the organisms remained viable and could be recovered from the liver. With others there was killing of pneumococci. The combination of rat antibody and complement was effective as an opsonin and produced about the same degree of killing as the same human components. When tested separately killing was not promoted by rat complement, human complement, or human antibody. However, when ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid-Mg2+ was added to block the classical pathway and preserve the alternative pathway there was significant pneumococcal killing which may have been complement mediated or due to an adverse effect of ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid-Mg2+ on the organisms. Fibronectin and C-reactive protein reduced the number of surviving microorganisms, although the change was not significant. Immunoglobulin G (IgG), IgM, IgG, or IgM with complement, and antibody + the classical complement pathway, significantly reduced survival of the organisms. The best killing occurred with antibody plus complement plus fibronectin, which reduced mean survival to 24% during the 1-h perfusion.