cssi/SciSciGPT-SciSciNet huggingface dataset:
Surgical Management of Left Ventricular–Aortic Discontinuity Complicating Bacterial Endocarditis

Abstract Successful hemodynamic repair of left ventricular–aortic discontinuity complicating bacterial endocarditis in 2 patients was achieved using a composite valve–woven Dacron tube graft. The prosthetic valve was sutured without tension into the remaining aortic annulus, ventricular muscle, and base of the aortic leaflet of the mitral valve. Use of the composite graft allows adequate debridement of the abscess, restores ventricular-aortic continuity, excludes the abscess wall from systemic pressure, and does not require saphenous vein coronary bypass. Total exclusion of the aortic root, as described, is a lifesaving alternative repair in the care of desperately ill patients with this condition.
Effect on Achievement of Written Responses to Programmed Learning Material for Students of Differing Academic Ability

A review of the relevant literature suggests the hypothesis that (1) the requirement of overt (written) responses to the program interferes with learning for students of high ability and (2) facili...
Kinetic Constants of the Human Renin and Human Angiotensinogen Reaction

The rate of formation of angiotensin was investigated for the reaction of angiotensinase-free human renin, at various states of purity, with angiotensinogen, in pooled, angiotensinase-free human serum. The velocity constant of this reaction and the Michaelis constant of the renin-substrate complex were determined. The concentration of angiotensinogen and of endogenous renin in human serum was also determined and, on the basis of these results, a procedure was designed for the indirect assay of human renin. This was carried out under a wide range of experimental conditions, for periods of incubation ranging from 10 min to 18 hours, for various concentrations of substrate, and for renin concentrations varying from 0.000025 to 0.20 unit/ml. The absence of angiotensinase made possible the prolonged incubation (18 hours) of a minute quantity of renin with a large amount of the renin substrate. The resultant formation of large amounts of angiotensin permitted its accurate assay in the dog.
Research in clinical dentistry

Oral diagnosis and oral medicine, growth and development and orthodontics, restorative dentistry, and prosthodontics are among the subjects covered in this review of clinical research.
Enhancing the Motor Skills of Children with Autism Spectrum Disorders: A Pool-based Approach

Children with autism spectrum disorders (ASDs) often experience difficulties with motor skill learning and performance. The pool is a unique learning environment that can help children with ASDs learn or improve aquatic skills, fitness, and social skills. A pool-based approach is also aligned with the elements of dynamic systems theory, which suggests that movement patterns develop as a result of a complex interaction between the environment, task, and learner. This article introduces pool-based activities for enhancing fundamental motor-skill development in children with ASDs, as well as task, environment, and learner variations. A lesson plan is also provided.
Correction: Gastric function in the acquired immunodeficiency syndrome (AIDS)

Excerpt To the editor:The two interesting articles by Lake-Bakaar and colleagues show that gastric acid is decreased in patients with the acquired immunodeficiency syndrome (AIDS) (1) and that pati...
Functional role of brain AT1 and AT2 receptors in the central angiotensin II pressor response

Intracerebroventricular (i.c.v.) angiotensin II (ANG II) increases vascular resistance and elicits a pressor response characterized by sympathetic nervous system activation (SNS component) and increased vasopressin (VP) secretion (VP component). This study examines the role of brain AT1 and AT2 ANG II receptors in mediating the pressor and renal hemodynamic effects of i.c.v. ANG II in conscious Sprague-Dawley rats. Mean arterial pressure, heart rate and renal vascular resistance responses to i.c.v. ANG II (100 ng in 5 microliters) were determined 10 min after i.c.v. injection of either the AT1 receptor antagonist, DuP 753 (1.0, 2.5, 5.0, 10.0 micrograms), the AT2 receptor ligand, PD 123319 (3.5 x [10(-6), 10(-4), 10(-2), 10(0)] micrograms), or both. In control rats, i.c.v. DuP 753 prevented the pressor response and the increase in renal vascular resistance that occurred following i.c.v. ANG II in a dose-dependent manner (P < 0.05), while i.c.v. PD 123319 was without affect. When the VP- and SNS components were studied individually, by preventing the SNS component with intravenous (i.v.) chlorisondamine or the VP component with a V1 receptor antagonist (i.v.) similar results were obtained; DuP 753 prevented the SNS component and significantly reduced the VP component. These results indicate that both central ANG II pressor components are mediated primarily by brain AT1 receptors. However, doses of DuP 753 were more effective when combined with 3.5 micrograms of PD 123319 than when given alone (P < 0.05), suggesting that the pressor effects of i.c.v. ANG II may involve activation of multiple ANG II receptor subtypes.
Discovery of an electrical post-pulse in the surroundings of a high voltage spark discharge

Abstract In the vicinity of a high voltage spark, an electrical pulse of negative polarity was observed. The pulse's behavior with respect to spark cathode composition, gas flow, spatial distribution, and related parameters was characterized. Suggestions as to the origin of the pulse are made. Attempts at observing laser-enhanced ionization in the post discharge time period are described.
Evaluation of magma energy power generation systems

Abstract A study of power generation schemes for magma energy systems is reported. In the magma energy concept thermal energy is removed from the molten region below the Earth's crust by circulation of water from the surface. The heated water is then assumed to drive a thermal cycle. Thermodynamic analyses of three general cycles are considered. In the first, the heated water is assumed to be used directly in an expander. This case is treated here with a variety of expander efficiencies to model conventional turbines as well as direct expansion devices when the entering state is liquid. A closed Rankine cycle (where the well fluid exchanges heat with the power cycle fluid) is also considered. Finally, a flashed cycle is also evaluated. The state of the input fluid to the power cycle is determined from a downhole model that represents many facets of the anticipated heat transfer and fluid flow. Power output and other results are presented as a function of mass flow rate, effective thermal conductivity of the heat exchange zone, and specific cycle parameters. Conclusions are drawn about which cycles show potential for maximizing power output. It is shown that the magma energy scheme holds great promise for economic power generation.
A Novel Peptide-IgG Conjugate, CAP18106–138-IgG, that Binds and Neutralizes Endotoxin and Kills Gram-Negative Bacteria

Although type-specific IgG directed to the O-polysaccharide antigen of bacterial lipopolysaccharide (LPS) is protective in most models of LPS or bacterial challenge, no currently available IgG binds to LPS from all gram-negative bacteria. The ability of a peptide-IgG conjugate, CAP18(106-138)-IgG, to bind and neutralize LPS, to kill gram-negative bacteria, and to protect in a sensitized mouse model of LPS toxicity was studied. CAP18(106-138)-IgG bound LPS from multiple gram-negative bacteria in four different binding assays. In a fluid-phase RIA, half-maximal binding of 5 microg/mL 3H-labeled LPS occurred at 5-10 microg/mL CAP18(106-138)-IgG, similar to binding with monoclonal type-specific IgG. CAP18(106-138)-IgG neutralized LPS, as assessed by LPS-induced coagulation of limulus amebocyte lysate and production of tumor necrosis factor in vitro, was bactericidal for a wide range of gram-negative bacteria, and decreased LPS-induced lethality in sensitized mice. Antibacterial peptide-IgG conjugates merit further study as a novel adjunctive therapy for gram-negative sepsis.
Social Marketing Applied to Economic Reforms

As social marketers seek to broaden their purview to include upstream applications, they are handicapped by the lack of examples of such applications. This article represents a retrofit of social marketing approaches developed by Andreasen to a major international intervention in Bosnia Herzegovina to reduce the array of impediments to private sector business investment and growth. The Bulldozer Initiative project, run by Herzberg, focused on two target audiences, businessmen and politicians, and sought participation by the former and support and legislative change from the latter. The Initiative was highly successful and resulted in a major change in the business climate and wide praise from an array of international agencies. Major components of the program closely conformed to ways in which social marketers would have constructed them.
Enkephalin-containing polypeptide levels in normal tensive and SHR rat adrenal glands

The levels of enkephalin-containing polypeptides (ECPs) in the adrenal glands of normal tensive rats (WKY) and spontaneously hypertensive rats (SHR) were compared. Innervated and denervated adrenals from both types of rats showed very similar levels of ECPs. The only difference observed was a small increase in the 18 kdal ECP and a concomitant decrease in the 12 kdal and 5.3 kdal ECPs in the innervated SHR rat adrenal gland. From these data it appears that the adrenal ECPs are not a major contributor to hypertension in the SHR rat nor does hypertension, at this age, affect the ECP levels.
Tertiary Interferograms in Fourier Transform Spectroscopy

Multiple passes, both within a semiconductor specimen and between the specimen surface and the interferometer, give rise to a series of extraneous "tertiary" interferograms in a Fourier transform spectrophotometer. These tertiary interferograms can lead to a possible error on the order of 1% in the measurement of the impurity content of a silicon wafer. However, this effect can be eliminated by a straightforward manipulation of the interferogram prior to transformation.
Changes in femoral robusticity and porosity during the reproductive cycle of the female alligator (Alligator mississippiensis).

To help understand the nature of skeletal changes during the reproductive cycle of the female alligator, we compared femoral robusticity (density) and porosity of cross-sections from the midshafts of femora from the following groups of female alligators: (1) immature; (2) pre-ovulatory; (3) postovulatory with soft-shelled oviducal eggs; (4) post-ovulatory with hard-shelled oviducal eggs; (5) post-ovulatory with eggs in the nest; (6) post-ovulatory with hatched eggs; and (7) mature, quiescent. Femora from alligators with eggs in the nest were significantly less robust (dense) than those of the other groups except those with hard-shelled oviducal eggs. Cross sections from the midshaft of femora from alligators with eggs in the nest were significantly more porous than those from all the other groups. The results indicated that calcium was mobilized from the femoral shaft shortly before eggs were laid and that femoral density returned to normal levels for mature alligators 1-2 months after egg-laying.
Dorsett-morse soybean collection trip to East Asia: 50 year retrospective

This paper is devoted to the analysis of the 4,451 soybean (Glycine max,) accessions collected by P. H. Dorsett and W. J. Morse during their plant exploration trip to east Asia 1929–1931. Until about 1950 the collection was used primarily for the development of vegetable type soybean cultivars. During this period many of the accessions were lost. Today only 945 of the original 4,451 accessions are available in the United States soybean germplasm collection. From the 1950s to the 1980s, as soybean production increased in the United States, so did plant pathogen problems. The Dorsett-Morse soybean accessions have been extremely valuable to plant pathologists and breeders as sources of resistance to certain pathogens. Individual genotypes in the collection have been used for genetic studies on morphological, physiological and biochemical traits. Due to the development and distribution of higher-yielding soybean cultivars, farmers in east Asia are no longer growing lower-yielding landraces. Although these landraces are now extinct in east Asia, many were collected by Dorsett and Morse and are preserved in the United States soybean collection. Over the years, the Dorsett-Morse collection has increased in value and will be as useful to soybean scientists in the future as it has been in its first 50 yr of existence.
Food of Forage Fishes in Western Lake Erie, 1975–76

In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.
Dendron-mediated self-assembly of highly PEGylated block copolymers: a modular nanocarrier platform

PEGylated dendron coils (PDCs) were investigated as a novel potential nanocarrier platform. PDCs self-assembled into micelles at lower CMCs than linear copolymer counterparts by 1–2 orders of magnitude, due to the unique architecture of dendrons. MD simulations also supported thermodynamically favourable self-assembly mediated by dendrons.
Receptor signaling in immune cell development and function

Immune cell development and function must be tightly regulated through cell surface receptors to ensure proper responses to pathogen and tolerance to self. In T cells, the signal from the T-cell receptor is essential for T-cell maturation, homeostasis, and activation. In mast cells, the high-affinity receptor for IgE transduces signal that promotes mast cell survival and induces mast cell activation. In dendritic cells and macrophages, the toll-like receptors recognize microbial pathogens and play critical roles for both innate and adaptive immunity against pathogens. Our research explores how signaling from these receptors is transduced and regulated to better understand these immune cells. Our recent studies have revealed diacylglycerol kinases and TSC1/2-mTOR as critical signaling molecules/regulators in T cells, mast cells, dendritic cells, and macrophages.
Quasitriangular Pointed Hopf Algebras Constructed by Ore Extensions

We study the quasitriangular structures for a family of pointed Hopf algebras which is big enough to include Taft's Hopf algebras Hn2, Radford's Hopf algebras HN,n,q,ν and E(n). We give necessary and sufficient conditions for the Hopf algebras in our family to be quasitriangular. For the case when they are, we determine completely all the quasitriangular structures. Also, we determine the ribbon elements of the quasitriangular Hopf algebras and the quasi-ribbon elements of their Drinfel'd double.
Dipole effects on cation-π interactions: Absolute bond dissociation energies of complexes of alkali metal cations to N-methylaniline and N,N-dimethylaniline

Threshold collision-induced dissociation of M+(nMA)x with Xe is studied using guided ion beam mass spectrometry, where nMA = N-methylaniline and N,N-dimethylaniline and x = 1 and 2. M+ includes the following alkali metal cations: Li+, Na+, K+, Rb+, and Cs+. In all cases, the primary dissociation pathway corresponds to the endothermic loss of an intact nMA ligand. The primary cross section thresholds are interpreted to yield 0 and 298 K bond dissociation energies (BDEs) for (nMA)x-1M+−(nMA) after accounting for the effects of multiple ion−neutral collisions, the internal and kinetic energy distributions of the reactants, and the dissociation lifetimes. Density functional theory calculations at the B3LYP/6-31G* level of theory are used to determine the structures of these complexes, which are also used in single-point calculations at the MP2(full)/6-311+G(2d,2p) level to determine theoretical BDEs. The results of these studies are compared to previous studies of the analogous M+(aniline)x complexes to exami...
Nitrous oxide (N2O) emissions in response to increasing fertilizer addition in maize (Zea mays L.) agriculture in western Kenya

National and regional efforts are underway to increase fertilizer use in sub-Saharan Africa, where attaining food security is a perennial challenge and mean fertilizer use in many countries is <10 % of nationally recommended rates. Increases in nitrogen (N) inputs will likely cause increased emissions of the greenhouse gas nitrous oxide (N2O). We established experimental plots with different rates of N applied to maize (Zea mays) in a field with a history of nutrient additions in western Kenya and measured N2O fluxes. Fertilizer was applied by hand at 0, 50, 75, 100, and 200 kg N ha−1 in a split application on March 22 and April 20, 2010. Gas sampling was conducted daily during the week following applications, and was otherwise collected weekly or biweekly until June 29, 2010. Cumulative fluxes were highest from the 200 kg N ha−1 treatment, with emissions of 810 g N2O–N ha−1; fluxes from other treatments ranged from 620 to 710 g N2O–N ha−1, but with no significant differences among treatments. Emissions of N2O during the 99-day measurement period represented <0.1 % of added fertilizer N for all treatments. Though limited to a single year, these results provide further evidence that African agricultural systems may have N2O emission factors substantially lower than the global mean.
Male engorgement factor: Role in stimulating engorgement to repletion in the ixodid tick, Dermacentor variabilis.

Mating in ticks results in profound physiological changes that eventually results in egg production. In the American dog tick, Dermacentor variabilis, mating causes partially blood-fed female ticks to commence rapid engorgement to repletion and eventual detachment from the host and egg laying. The peptidic male pheromone (engorgement factor α/β) transferred to the female during mating is known only from a single tick species, Amblyomma hebraeum, and was shown to consist of two peptides produced in the testis/vas deferens (TVD) and not in the male accessory gland (MAG). In the current study, we obtained 2704 bp of sequence data for efα from D. variabilis, of 7 kb as determined by Northern blot, and show that it is also present in the Southern cattle tick, Rhipicephalus microplus and the deer tick, Ixodes scapularis. Analysis of the male gonad transcriptome by pyrosequencing produced 563,093 reads of which 636 matched with efα; none matched with efβ. No evidence of efβ orthologs could be found in any publicly available database including the I. scapularis genome. Silencing efα in male ticks failed to significantly reduce the engorgement weight of females compared to controls. Injection of sephadex beads, replete female synganglia, fed male MAG, fed male TVD, or replete female vagina/seminal receptacle (VA/SR), separately, failed to initiate feeding to repletion like that found in normally mated females. However, a small percentage of females injected with VA/SR that fed beyond the arbitrary weight for repletion of 300 mg, produced brown eggs (an indication of vitellogenin uptake by the oocytes). The greatest effect was observed in female ticks injected with a suspension of MAG and TVD combined; 50% fed to repletion and all of these dropped off from the host and laid brown eggs. The effect was abolished if the aqueous fraction of the MAG/TVD homogenate only was injected suggesting that EF in ticks is a non-secreted membrane-bound or intracellular protein. Overall, these data suggest that EFα in D. variabilis is not an engorgement factor.
Reparameterizing the generalized linear model to accelerate gibbs sampler convergence

Albert and Chib introduced a complete Bayesian method to analyze data arising from the generalized linear model in which they used the Gibbs sampling algorithm facilitated by latent variables. Recently, Cowles proposed an alternative algorithm to accelerate the convergence of the Albert-Chib algorithm. The novelty in this latter algorithm is achieved by using a Hastings algorithm to generate latent variables and bin boundary parameters jointly instead of individually from their respective full conditionals. In the same spirit, we reparameterize the cumulative-link generalized linear model to accelerate the convergence of Cowles’ algorithm even further. One important advantage of our method is that for the three-bin problem it does not require the Hastings algorithm. In addition, for problems with more than three bins, while the Hastings algorithm is required, we provide a proposal density based on the Dirichlet distribution which is more natural than the truncated normal density used in the competing algo...
IDENTIFICATION OF TYPES II, IX AND X COLLAGENS AT THE INSERTION SITE OF THE BOVINE ACHILLES TENDON

Abstract Achilles tendinous collagen fibrils insert into the calcaneus by first passing through a zone that is defined histologically as fibrocartilaginous. This zone consists of four regions: tendon proper, non-mineralized and mineralized fibrocartilage and bone. The function of this zone has not yet been clearly defined. To gain more insight into the role of this fibrocartilaginous zone, collagens present in the zone of the Achilles tendon-calcaneus interface were isolated and characterized. Types II, IX and X collagens were identified in the pepsin digests of the tissue harvested from the bovine Achilles tendon-calcaneus interface. Western blotting using specific antisera to types II, IX and X collagens confirmed the identity of these collagens. Immunofluorescence localization placed type X collagen predominantly in the mineralized zone of the tendon-calcaneus junction, while type IX collagen was distributed throught the the insertion site. The presence of the cartilage-specific collagens at the Achilles tendon-calcancus-interface suggests that this zone is cartilaginous in nature. The presence of type X collagen at this junction is not clear, but our present findings go along with the previous report which showed that type X collagen is present in the mineralized zone of the medial collateral ligament femoral insertion site. These data suggest that type X collagen may be a resident of mineralized fibrocartilaginous zones of tendon or ligament-bone junctions and may participate in anchoring ligament or tendon to bone.
E-Shopping, Spatial Attributes, and Personal Travel: A Review of Empirical Studies

In an era of unprecedented proliferation of e-shopping, retailers and planners are interested in the changes that it will bring. Recently, several empirical studies have explored the influence of spatial attributes on e-shopping and its impacts on individuals' activity travel patterns. This study evaluates the progress that has been made, provides a critique of previous research, and discusses the improvements in research methodology needed to enhance understanding of the connections among e-shopping, spatial attitudes, and travel behavior. In particular, this review highlights the importance of (a) controlling for shopping preferences and household shopping responsibility, (b) exploring multiple dimensions of travel behavior, (c) testing the connections that depend on time scale, (d) deconstructing the shopping process, (e) differentiating product types, (f) demonstrating the oomph of coefficient estimates, (g) integrating shopping surveys and activity diaries, and (h) identifying shopping accessibility ...
Have we ignored the role of oncotic pressure in the pathogenesis of glomerulosclerosis

Focal and segmental glomerulosclerosis (FSGS) develops in a number of renal conditions, especially those associated with severe nephrotic syndrome or a reduction in renal mass. Strong evidence suggests that in diseases associated with reduced renal mass that FSGS develops as a consequence of elevated glomerular hydrostatic pressure (P(GC)) resulting from single nephron hyperfiltration. In nephrotic syndrome, the contribution of an elevated P(GC) is less certain. We hypothesize that in both conditions there is an elevation in net ultrafiltration pressure (P(UF)), which in nephrotic syndrome is secondary to a reduction in glomerular plasma oncotic pressure (piGC) and in conditions with reduced renal mass is secondary to an elevated P(GC). The elevated P(UF) would result in increased convective forces with trafficking and deposition of macromolecules in the mesangium, a process that could trigger local cytokine release with the stimulation of cell proliferation and matrix synthesis. In addition to explaining why FSGS develops in both nephrotic syndrome and with reduced renal mass, the hypothesis explains why the lesion in FSGS is segmental and preferentially involves the hilar area. This is because P(UF) varies along the glomerular capillary, being highest at the proximal (afferent arteriolar) end. In contrast, an elevated P(GC) alone does not readily explain the segmental nature of FSGS, because P(GC) remains relatively constant within the glomerulus. Thus, the hypothesis suggests an important role for the plasma oncotic pressure in the pathogenesis of FSGS. Future studies examining the role of P(UF) and piGC in FSGS would be of interest.
The "Year of the Woman" in Context A Test of Six Explanations

The 1992 election saw a virtual doubling of the number of women in the U.S. House of Representatives. Although much of this may be attributed to record turnover rates, I focus in this article on wh...
Comparison of three sampling and analytical methods for the determination of airborne hexavalent chromium.

A field study was conducted with the goal of comparing the performance of three recently developed or modified sampling and analytical methods for the determination of airborne hexavalent chromium (CrVI). The study was carried out in a hard chrome electroplating facility and in a jet engine manufacturing facility where airborne CrVI was expected to be present. The analytical methods evaluated included two laboratory-based procedures (OSHA Method ID-215 and NIOSH Method 7605) and a field-portable method (NIOSH Method 7703). These three methods employ an identical sampling methodology: collection of CrVI-containing aerosol on a polyvinyl chloride (PVC) filter housed in a sampling cassette, which is connected to a personal sampling pump calibrated at an appropriate flow rate. The basis of the analytical methods for all three methods involves extraction of the PVC filter in alkaline buffer solution, chemical isolation of the CrVI ion, complexation of the CrVI ion with 1,5-diphenylcarbazide, and spectrometric measurement of the violet chromium–diphenylcarbazone complex at 540 nm. However, there are notable specific differences within the sample preparation procedures used in three methods. To assess the comparability of the three measurement protocols, a total of 20 side-by-side air samples were collected, equally divided between a chromic acid electroplating operation and a spray paint operation where water soluble forms of CrVI were used. A range of CrVI concentrations from 0.6 to 960 µg m−3, with CrVI mass loadings ranging from 0.4 to 32 µg, was measured at the two operations. The equivalence of the means of the log-transformed CrVI concentrations obtained from the different analytical methods was compared. Based on analysis of variance (ANOVA) results, no statistically significant differences were observed between mean values measured using each of the three methods. Small but statistically significant differences were observed between results obtained from performance evaluation samples for the NIOSH field method and the OSHA laboratory method.
In-Ice Calibration Tests for an Elongated, Uniaxial Brass Ice Stress Sensor

Les essais de calibrage en laboratoire ont ete conduit dans un bloc de glace dans lequel le capteur a ete gele, pour determiner les caracteristiques de la reponse du capteur
Canpow: A Program that Estimates Effect or Sample Sizes Required for Canonical Correlation Analysis:

The importance of interpreting significance test statistics in the framework of sample' size and of evaluating power against Type II error has been increasingly recognized by researchers. The paper describes a computer program, written in BASIC source code, that can be employed to evaluate research situations in which canonical correlation analysis will be employed. The program, CANPOW, can be employed to evaluate the effects of sample size variations, given an actual or expected set effect size, and to evaluate the effects of variations in effect sizes, given an actual or expected sample size. To assist interpretation, comparisons are also presented in various graphs and figures.
Postnatal development of nitric oxide synthase expression in the mouse superior colliculus.

Since nitric oxide has a role in the refinement of the retinal projection to the superior colliculus (SC), we studied the onset of neuronal nitric oxide synthase (nNOS) expression in the mouse SC in order to compare its development with that of the refinement process. Sections from animals at ages P1, P5, P8, P11, P15, and P21 and adults were examined with nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry or immunocytochemistry using an antibody directed against nNOS. At all ages there was a wedge of labeled neurons in the dorsolateral periaqueductal gray extending into the deep layers of the SC. At P1 there was also a single superficial band of labeled neurons within the region that will become the intermediate gray layer (IGL). By P5, labeled neurons were also seen in what will become the superficial gray layer. There was a ventral to dorsal progression in nNOS expression with substantial changes in the numbers of labeled neurons in the different laminae between P5 and adulthood. The number of labeled neurons in the IGL peaked at P15, whereas in the superficial layers the numbers continued to increase through P21 and then declined in adults. At all ages these neurons represented a variety of morphological cell types. The onset of nNOS expression in the different laminae is earlier than has been reported in studies using NADPHd as a marker for nNOS. The temporal and spatial patterns of nNOS expression reported here match more closely the time course of pathway refinement in the SC, providing additional evidence for the involvement of nitric oxide in this process. J. Comp. Neurol. 427:581–592, 2000. © 2000 Wiley-Liss, Inc.
Simultaneous Determination of Ethanol and Chloroform in Liquid Cough Preparations by Gas Chromatography

A gas chromatographic procedure using a styrene-divinylbenzene polymer as column-packing material is described. The use of this column allows for the complete separation and simultaneous determination of ethanol and chloroform contained in liquid cough preparations.
Immobilization, hybridization, and oxidation of synthetic DNA on gold surface: electron transfer investigated by electrochemistry and scanning tunneling microscopy.

Fundamental understanding of interfacial electron transfer (ET) among electrolyte/DNA/solid-surface will facilitate the design for electrical detection of DNA molecules. In this report, the electron transfer characteristics of synthetic DNA (sequence from pathogenic Cryptosporidium parvum) self-assembled on a gold surface was electrochemically studied. The effects of immobilization order on the interface ET related parameters such as diffusion coefficient (D0), surface coverage (θR), and monolayer thickness (di) were determined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). DNA surface density (ΓDNA) was determined by the integration of the charge of the electro-oxidation current peaks during the initial cyclic voltammetry scans. It was found that the DNA surface densities at different modifications followed the order: ΓDNA (dsS-DNA/Au) > ΓDNA (MCH/dsS-DNA/Au) > ΓDNA (dsS-DNA/MCH/Au). It was also revealed that the electro-oxidation of the DNA modified gold surface would involve the oxidation of nucleotides (guanine and adenine) with a 5.51 electron transfer mechanism and the oxidative desorption of DNA and MCH molecules by a 3 electron transfer mechanism. STM topography and current image analysis indicated that the surface conductivity after each surface modification followed the order: dsS-DNA/Au < MCH/dsS-DNA/Au < oxidized MCH/dsS-DNA/Au < Hoechst/oxidized MCH/dsS-DNA/Au. The results from this study suggested a combination of variations in immobilization order may provide an alternative approach for the optimization of DNA hybridization and the further development for electrical detection of DNA.
Effects of freshwater shrimp assemblages on benthic communities along an altitudinal gradient of a tropical island stream

1. In tropical island stream ecosystems freshwater shrimps are often the dominant macroconsumers and can play an important role in determining benthic community composition. However, most studies of the ecological role of shrimps are limited to high-altitude shrimp-dominated sites where other biota (fishes and snails) are absent or significantly less abundant than at lower altitudes. 2. We examined how effects of different shrimp assemblages on benthic communities changed along an altitudinal gradient in a tropical island stream in Puerto Rico. We used electroshocking and observations to quantify abundance and taxonomic composition of shrimp assemblages at three sites (300, 90 and 10 m a. s. l) along the Rio Espiritu Santo. We also experimentally manipulated access of shrimps to the benthic environment simultaneously at each site using electric fences over a 35-day period. 3. At the high-altitude site, exclusion of shrimps (predominantly Atya spp. and Xiphocariselongata) resulted in significantly greater accrual of organic and inorganic material, chlorophyll a and algal biovolume. In the absence of shrimps, the algal community was dominated by filamentous green algae (Chlorophyta: Oedogonium and Rhizoclonium). Excluding shrimps did not affect total insect biomass but significantly increased sessile chironomids (Diptera: Chironomidae). We observed similar treatment effects at the mid-altitude site where shrimps (primarily Macrobrachium spp. and X. elongata) occurred at lower densities. In contrast, at the low-altitude site there were no treatment differences in organic and inorganic material, chlorophyll a, algal biovolume, algal assemblage composition and insects. 4. The lack of treatment differences at the low-altitude site was probably because of very high densities of grazing snails (Thiaragranifera and Neritina spp.) which reduced organic and inorganic resources and obscured potential shrimp effects. 5. This study demonstrates that freshwater shrimps can play an important role in determining benthic community composition; however, their effects vary and appear to depend on the presence of other biota. This study suggests that loss of shrimps as a result of anthropogenic disturbances will have different effects on the stream community depending upon location along the altitude gradient.
Trapped Ions, Laser Cooling, and Better Clocks

Ions that are stored in electromagnetic "traps" provid the basis for extremely high resolution spectroscopy. By using lasers, the kinetic energy of the ions can be cooled to millikelvin temperatures, thereby suppressing Doppler frequency shifts. Potential accuracies of frequency standards and clocks based on such experiments are anticipated to be better than one part in 10 15 .
The effect of tin-protoporphyrin on bilirubin conjugation and production in cholestatic rats.

Tin-protoporphyrin (SnP) is actively being - - investigated for treatment of exaggerated neonatal hyper- bilirubinemia. Because both bilirubin coniugation and " - excretion are immature in the human newborn, we inves- tigated the effect of SnP on bilirubin-conjugating mecha- nisms and the efficacy of SnP in suppressing serum bili- rubin levels in adult rats made cholestatic by surgical bile duct ligation. Male Sprague-Dawley rats received SnP (100 pmollkg body weight) subcutaneously either 24 h before or 24 or 48 h after bile duct ligation. Serum and urine specimens were collected 72 h after bile duct ligation and analyzed for bilirubin and its conjugates. As compared to a control group that received bile duct ligation and a sodium phosphate buffer injection, all SnP-treated animals had a significant lowering of total serum bilirubin levels. No differences in the distribution of serum bilirubin mono- and diconjugates in serum or urine samples were observed. However, the concentrations of covalently linked bilirubin- protein conjugates were significantly higher in the control cholestatic rats when compared to the SnP-treated animals. SnP effectively lowers serum bilirubin levels in rats with an impaired biliary excretory pathway for SnP. There was no adverse effect on bilirubin conjugation and no observable toxicity. (Pediatr Res 23: 163-166, 1988)
The Effect of Trace Element Additions on the Grain Boundary Composition of Ir + 0.3% W Alloys

Iridium alloys are currently used as cladding and post-impact containment material for radioactive fuel in radioisotope thermoelectric generator heat sources. In this application, the cladding must exhibit at least 15% elongation during high temperature impact (h.t.i.), which for purposes of this study will denote an overall elongation rate of 85 m/s with a gauge length of 1.27 cm in the temperature range 1200—1500 °C. Liu & Inouye (1976) have reported that doped Ir + 0.3% W normally fails intergranularly during h.t.i., with elongation between 3 and 15 %. Intergranular failure at lower temperatures and strain rates has been reported by others, and has been attributed to the presence of impurities or precipitates at the grain boundaries. Hecker et al . (1979) and White et al . (1979) have recently studied the composition of grain boundaries in Ir and Ir + 0.3% W by using Auger electron spectroscopy (A.e.s.). They were unable to find any impurity segregated to the grain boundaries, and concluded that intergranular fracture is intrinsic to Ir, and not related to impurities.
Economics of operations management: A research perspective

In response to intense competition from overseas in the last two decades, U.S. companies have instituted a variety of management practices in their quest to improve their competitiveness. Among the many practices that have been adopted by a large number of firms are just-in-time, total quality management, worker empowerment, and design for manufacturability. However, there has been little systematic analysis of the organizational factors that drive the adoption of these practices as well as their successful implementation. This paper posits that the theories and methods from economics can provide a useful aid in such an analysis. Using the basic tenets of economics, a structural framework is proposed to highlight critical issues in operations management that deserve attention. Examples from industry are used to illustrate how the framework may provide answers to questions that have received little attention in the research literature.
Computational tests of angular momentum decoupling approximations for pressure broadening cross sections

The utility of several approximate scattering methods for predicting collision induced spectral pressure broadening has been tested by comparison with accurate close coupling results. In particular, broadening of the pure rotational spectra of HD, HCl, CO, and HCN - all perturbed by low energy collisions with He atoms - has been computed using the effective potential formalism of Rabitz, the decoupled l-dominant approximation of DePristo and Alexander, and the j(2)-conserving coupled states method of McGuire and Kouri. For this last method, pressure broadening cross sections have been obtained with the new, correct expression recently derived by Goldflam and Kouri as well as with an earlier formalism based on an incorrect labeling of the scattering matrices. These methods were found to be generally diasppointing for predicting pressure broadening with the exception of the new, correctly formulated j(2)-conserving coupled states method which was found to agree quantitatively (better than 5%) with close coupling values for all cases studied.
Models for the adsorption of organic compounds at gas-water interfaces.

The solvation parameter model is used to characterize interactions responsible for adsorption at the gas–water interface for bulk water at 15 and 25 °C, snow at −6.8 °C, mineral-supported water films (alumina, calcium carbonate and quartz) at 15 °C, and dry soil at 15 °C. The mineral-supported water films and dry soil adsorption data are modeled at different relative humidities in the range 40–99%. The models produce satisfactory results with standard errors of the estimate of 0.12 to 0.17 for regression of the model predicted adsorption equilibrium constants against the experimental values (range for equilibrium constants −2 to −7 log units). The water surface is polar with a significant capacity for dipole-type and hydrogen-bonding interactions. In addition, it is strongly electron lone pair repulsive. Dispersion interactions favor adsorption at the water surface. Mineral-supported water films at relative humidities greater than 40% demonstrate adsorption properties similar to bulk water. The adsorption characteristics, however, depend on the relative humidity and the nature of the support. In the case of dry soil the adsorption properties at different relative humidities cannot simply be explained by adsorption of a water film covering the soil surface and the changes in adsorption characteristics with relative humidity are more complex than the mineral-supported water films.
Dynamic Efficiency with Learning by Doing

This article focuses on the measurement of economic efficiency of firms in an industry in a dynamic framework, where R&D investments and learning experience play critical roles. Dynamic aspects of cost and production efficiency and the impact of capital through learning by doing are developed here in semiparametric forms. The production and cost frontiers estimated here for the US computer industry over the period 1987–98 are robust in the sense that no specific functional form need be assumed. The empirical estimates measure the pattern of level and growth efficiency in the computer industry, which has undergone rapid changes in recent years.
MOLECULAR DESIGNER: An interactive program for the display of protein structure on the IBM-PC

A BASIC interactive graphics program has been developed for the IBM-PC which utilizes the graphics capabilities of that computer to display and manipulate protein structure from coordinates. Structures may be generated from typed files, or from Brookhaven National Laboratories' Protein Data Bank data tapes. Once displayed, images may be rotated, translated and expanded to any desired size. Figures may be viewed as ball-and-stick or space-filling models. Calculated multiple-point perspective may also be added to the display. Docking manipulations are possible since more than a single figure may be displayed and manipulated simultaneously. Further, stereo images and red/blue three-dimensional images may be generated using the accompanying DESIPLOT program and an HP-7475A plotter. A version of the program is also currently available for the Apple Macintosh. Full implementation on the Macintosh requires 512 K and at least one disk drive. Otherwise this version is essentially identical to the IBM-PC version described herein.
Climate Change or Social Change? Environmental and Leftist Praxis and Participatory Action Research

This work seeks to advance and synthesize leftist political and environmental theory and enhance historical and contemporary understanding of environmental activism, especially related to the movement to halt climate change. We share findings from our participatory action research (PAR) on the internal dynamics and debates among the three main climate activist networks mobilizing at the United Nations Framework Convention on Climate Change meetings in Copenhagen in 2009, those of the reformist Climate Action Network (CAN), the more marxian-inspired Climate Justice Now! (CJN), and the autonomist and anarchistic Climate Justice Action (CJA). We elucidate how leftist reformist and especially the more radical currents are engaging with non- or anti-Western indigenous praxis to forge the contemporary transnational environmental movement. Este trabajo busca avanzar y sintetizar la teoria politica izquierdista y la medioambiental y enriquecer el entendimiento historico y contemporaneo del activismo medioambienta...
Evolving Sensor Morphology on a Legged Robot in Niche Environments

This paper discusses the issue of evolution of morphology and automatic design, specifically evolving sensor morphology on a legged hexapod robot in niche environments. The evolution of sensor morphology in different environments, in particular, type of sensor, angle of heading and its effect on controller complexity for a simulated hexapod robot are described. This automatic design method enables the system to decipher relevant stimuli in an environment, increases the efficiency of the robot and also indirectly alters the controller of the robot to take advantage of the characteristics of a given environment.
Superconductivity in PdAg alloys

Abstract The tight binding coherent potential approximation is used to calculate the electron densities of states (DOS) for various concentrations of the Pd 1− y Ag y H x system. The DOS are used in the evaluation of the electron-phonon coupling constant λ and the superconducting temperature T c . Our results reproduce the experimentally determined behavior of the superconducting transition temperature's dependency on Ag concentration, and provide a satisfactory explanation of the mechanism of superconductivity in this system.
Interfacial area transport of vertical upward steam–water two-phase flow in an annular channel at elevated pressures

Abstract The interfacial area transport of vertical, upward, steam-water two-phase flows in a vertical annular channel has been investigated. The inner and outer diameters of the annular channel were 19.1 and 38.1 mm, respectively. The test section had a 2845 mm heated section followed by a 1632 mm unheated section. Fifty seven experimental conditions were selected, which cover bubbly, cap-slug, and churn-turbulent flows. Each one of flow conditions was obtained by achieving different inlet sub-cooling temperatures, liquid velocities, wall heat flux or system pressures. The local flow parameters, such as void fraction, interfacial area concentration, and bubble interface velocity, were measured at different radial positions for the five axial locations. The radial and axial evolutions of local flow structure were interpreted based on presence of wall superheat, wall nucleation, bulk condensation and evaporation, bubble sizes, coalescence and break-up mechanisms. The measured data can be used for both the assessment of the bubble coalescence/breakup models and the development of closure models for computational fluid dynamics.