cssi/SciSciGPT-SciSciNet huggingface dataset:
Paneth cell function: phagocytosis and intracellular digestion of intestinal microorganisms: I. Hexamita muris

At the ultrastructural level we have examined the interactions between the intestinal flagellate, Hexamita muris, and the epithelial cells of the duodenal crypts where trophozoites of this parasite were particularly concentrated in infected rats. Both structurally intact and partially digested trophozoites of Hexamita were commonly found within digestive vacuoles in Paneth cells, but were never encountered intracellularly in any other cell type. Although up to eight intact trophozoites were observed in vacuoles within a single Paneth cell, no pathological effects on the Paneth cells were noted. Varying stages in the digestion of trophozoites were observed and because of the complex structure of the trophozoites, especially the resistance of flagellar microtubules to digestion, it was possible to reconstruct the evolution of residual bodies from phagolysosomes. These results indicate that Paneth cells can function as fixed phagocytes and suggest, therefore, that they play a role in controlling the intestinal flora in the crypt of Lieberkuhn.
Influence of Naturally Occurring Humic Acids on Biodegradation of Monosubstituted Phenols by Aquatic Bacteria

Samples of the microbial community from Lake Michie, a mesotrophic reservoir in central North Carolina, were adapted to various levels (100 to 1,000 μg/liter) of natural humic acids in chemostats. The humic acids were extracted from water samples from Black Lake, a highly colored lake in the coastal plain of North Carolina. After adaptation, the microbial community was tested for its ability to degrade the monosubstituted phenols m-cresol, m-aminophenol, and p-chlorophenol. Adaptation to increasing levels of humic acids significantly reduced the ability of the microbial communities to degrade all three phenols. The decline in biodegradation was accompanied by a decrease in the number of specific compound degraders in the adapted communities. Short-term exposure of the community to increasing levels of humic acids had no significant effect on the ability of the community to degrade m-cresol. Thus the suppressive effect of humic acids on monosubstituted phenol metabolism was the result of long-term exposure to the humic materials. Increasing the levels of inorganic nutrients fed to the chemostats during the humic acid adaptation had little effect on the suppressive influence of the humic acids, indicating that nutrient limitation was probably not responsible for the metabolic suppression. The results of the study suggest that long-term exposure to humic acids can reduce the ability of microbial communities to respond to monosubstituted phenols.
The Potential Effects of Elevated Co2 and Climate Change on Tropical Forest Soils and Biogeochemical Cycling

Tropical forests are responsible for a large proportion of the global terrestrial C flux annually for natural ecosystems. Increased atmospheric CO2 and changes in climate are likely to affect the distribution of C pools in the tropics and the rate of cycling through vegetation and soils. In this paper, I review the literature on the pools and fluxes of carbon in tropical forests, and the relationship of these to nutrient cycling and climate. Tropical moist and humid forests have the highest rates of annual net primary productivity and the greatest carbon flux from soil respiration globally. Tropical dry forests have lower rates of carbon circulation, but may have greater soil organic carbon storage, especially at depths below 1 meter. Data from tropical elevation gradients were used to examine the sensitivity of biogeochemical cycling to incremental changes in temperature and rainfall. These data show significant positive correlations of litterfall N concentrations with temperature and decomposition rates. Increased atmospheric CO2 and changes in climate are expected to alter carbon and nutrient allocation patterns and storage in tropical forest. Modeling and experimental studies suggest that even a small increase in temperature and CO2 concentrations results in more rapid decomposition rates, and a large initial CO2 efflux from moist tropical soils. Soil P limitation or reductions in C:N and C:P ratios of litterfall could eventually limit the size of this flux. Increased frequency of fires in dry forest and hurricanes in moist and humid forests are expected to reduce the ecosystem carbon storage capacity over longer time periods.
The Cytoplasmic Domain of αIIbβ3: A TERNARY COMPLEX OF THE INTEGRIN α AND β SUBUNITS AND A DIVALENT CATION

Abstract Peptides corresponding to the cytoplasmic tails of the α (α(985-1008)) and β (β(713-762)) subunits of the integrin receptor αβ (glycoprotein IIb-IIIa) were synthesized and used to characterize their interaction with cations and with one another. α(985-1008) was found to contain a functional cation binding site as assessed by both terbium luminescence and electrospray ionization mass spectroscopy. The binding of Tb to α(985-1008) was of high affinity (K = 8.8 ± 5.2 nM), occurred with a 1:1 stoichiometry, and was mediated by its acidic carboxyl terminus (α(999-1008), PLEEDDEEGE). The affinity of this site for divalent cations was in the micromolar range, suggesting that this site would be constitutively occupied in the intracellular environment. Incubation of α(999-1008) with β(713-762) resulted in the formation of a complex, both in the presence and absence of cations. The interactive site for α(999-1008) in β was mapped to β(721-740), and complex formation was associated with a stabilization of secondary structure as assessed by circular dichroism. Both a binary (α(985-1008)•β(721-740)) and a ternary (Tb•α(999-1008)•β(721-740)) complex were detected by mass spectroscopy, but the distribution and intensity of the mass/charge peaks were distinct. These difference may reflect the involvement of distinct cation coordination sites and the formation of salt bridges in stabilizing the ternary complex. These data demonstrate the formation of a novel entity composed of the cytoplasmic tails of α and β and a cation which may constitute a functional intracellular domain.
R-Plasmid Transfer to and from Escherichia coli Strains Isolated from Human Fecal Samples.

Strains of Escherichia coli recently isolated from human feces were examined for the frequency with which they accept an R factor (R1) from a derepressed fi+ strain of E. coli K-12 and transfer it to fecal and laboratory strains. Colicins produced by some of the isolates rapidly killed the other half of the mating pair; therefore, conjugation was conducted by a membrane filtration procedure whereby this effect was minimized. The majority of fecal E. coli isolates accepted the R factor at lower frequencies than K-12 F−, varying from 10−2 per donor cell to undetectable levels. The frequencies with which certain fecal recipients received the R-plasmid were increased when its R+ transconjugant was either cured of the R1-plasmid and remated with the fi+ strain or backcrossed into the parental strain. The former suggests the loss of an incompatibility plasmid, and the latter suggests the modification of the R1-plasmid deoxyribonucleic acid (DNA). In general, the fecal R+E. coli transconjugants were less effective donors for K-12 F− and heterologous fecal strains than was the fi+ K-12 strain, whereas the single strain of Citrobacter freundii examined was generally more competent. Passage of the R1-plasmid to strains of salmonellae reached mating frequencies of 10−1 per donor cell when the recipient was a Salmonella typhi previously cured of its resident R-plasmid. However, two recently isolated strains of Salmonella accepted the R1-plasmid from E. coli K-12 R+ or the R+E. coli transconjugants at frequencies of 5 × 10−7 or less.
THE REPLICATION OF BACTERIOPHAGE MS2. II. AN IN VIVO SPECIFICITY FOR THE SYNTHESIS OF INFECTIVE RNA.

Multiple infection with wild-type MS2 and a plaque-morphology mutant of MS2 is demonstrated. An infectivity assay for phage RNA is described and growth curves for intracellular infective RNA in MS2-infected cells are presented which demonstrate the presence of a pool of infective RNA prior to the appearance of progeny virus particles. Experiments are described which indicate that the synthetic system established in an MS2-infected cell will not be used to produce infective RNA of a genetically distinguishable superinfecting phage.
Operation of a DNA-based autocatalytic network in serum

The potential for inferring the presence of cancer by the detection of miRNA in human blood has motivated research into the design and operation of DNA-based chemical amplifiers that can operate in bodily fluids. As a first step toward this goal, we have tested the operation of a DNA-based autocatalytic network in human serum and mouse serum. With the addition of sodium dodecyl sulfate to prevent degradation by nuclease activity, the network was found to operate successfully with both DNA and RNA catalysts.
A Novel Catalytic Strategy for the Production of Liquid Fuels from Ligno-cellulosic Biomass

Abstract Levulinic acid has recently been identified as a potential platform chemical that can be produced from agricultural waste and can lead to specialty chemicals, fuel additives and liquid fuels. Based on this versatile molecule, we have developed a catalytic cascade approach to convert solid cellulose into liquid hydrocarbon fuels for use in the transportation sector. Following a systems approach, a conceptual process synthesis effort was undertaken, leading to a novel process that combines the mentioned catalytic cascade with proper separation and recycle operations. A techno-economic analysis based on detailed simulation (accounting for experimental reaction conditions and yields) as well as detailed equipment sizing and costing was performed, followed by sensitivity analysis studies to identify the key economic parameters. Furthermore, to assess its economic attractiveness, the process was compared to a benchmark lignocellulosic bio-ethanol production facility. Finally, we considered two different types of biomass. Our studies indicate that the proposed strategy is economically attractive when biomass with high C 6 -sugar content is used.
Multicenter transformations of the methyl ligand in CH3Os3Au carbonyl cluster complexes: Synthesis, characterization and DFT analyses ☆

Abstract Os3(CO)11(NCCH3) and Os3(CO)10(NCCH3)2 react with (CH3)AuPPh3 to yield the new Os3Au cluster complexes, Os3(CO)10(μ-O CCH3) (AuPPh3), 1 and Os3(CO)9(μ-η3-CH) (μ-H)2(μ-AuPPh3), 2 containing bridging acetyl and bridging methylidyne ligands, respectively, by two competing reaction pathways: 1) a methyl migration/CO insertion pathway that produces a complex with a bridging acetyl ligand. and 2) C–H bond cleavage transformations via a series of decarbonylated intermediates containing an agostically coordinated bridging methyl group, a bridging methylene group, a triply bridging methylidyne ligand and bridging hydride ligands. It has also been found that carbon monoxide can induce shifts of the bridging hydride ligands back to methylidyne ligand in 2 with subsequent cleavage of Os–Au and Os–Os bonds to yield two open cluster complexes (CH3)Os3(CO)12AuPPh3, 4 and (CH3)Os2(CO)8AuPPh3, 5 having terminally coordinated methyl ligands. The open cluster complex 4 can be converted back to 1 and 2 via decarbonylation process by using either thermal or irradiation treatments. The CO dissociation mechanisms related to the CH bond transformation processes were studied by DFT computational analyses. It has been demonstrated that the Os3Au(CH3) cluster provides a robust platform to studying multicenter C–H bond transformations and for C–C bond formation via methyl migration/CO insertion processes.
Galvanomagnetic effects in polymeric sulfur nitride, (SN)x

Magnetoresistance of (SN)x crystals has been measured for conductivity both parallel and perpendicular to the crystalline b-axis. A measureof the intrinsic conductivity anisotropy is obtained from the dependence of Δρ⊥/ρ⊥ on the orientation of the crystal in the magnetic field. The galvanomagnetic tensor has been calculated from the theoretical Fermi surface anisotropy and compared with experimental results.The electron and hole mobilities parallel to the (SN)x chains are 430 cm2/V-sec and 600 cm2/V-sec respectively with a scattering time of ~10−13 sec.
Dissolved and particulate Fe in the western and central North Pacific: Results from the 2002 IOC cruise

[1] The goals of the 2002 Intergovernmental Oceanographic Commission (IOC) cruise were to examine the variability in dissolved and particulate Fe over the cruise track, relate this variability to atmospheric aerosol Fe input, and examine the relationships between Fe, nitrate, and dust deposition with regards to Fe limitation particularly in the subarctic North Pacific. Dissolved Fe in the surface waters was quite variable, ranging from 0.10 nM to 0.30 nM. Dissolved Fe in the vertical profiles showed significant variability, the most prominent feature being an Fe maximum (∼1.5 nM Fe) associated with a broad nitrate maximum at 400–1000 m in the western subarctic gyre. Deep water Fe values in the subarctic region ranged from 0.8 nM to 1.1 nM. Subtropical gyre surface water dissolved Fe values were also quite variable, ranging from ∼0.15 nM to 0.4 nM. Intermediate and deep water Fe values were on the order of 0.6–0.9 nM. Significant differences were observed between total dissolvable Fe and dissolved Fe (TDFe-DFe) in surface waters over the course of the cruise track, and these differences are discussed in terms of particulate Fe and possible sources of Fe to surface waters. Finally, nitrate:Fe ratios in the western subarctic gyre, atmospheric dust flux estimates based on surface water aluminum concentrations, and aerosol Fe fluxes from ship-based aerosol collections are used to evaluate the relative importance of atmospheric and/or continental Fe input versus upwelling fluxes of Fe to the surface waters of the subarctic gyre.
The molecular pathology of sarcomas

Sarcomas are rare malignancies of mesenchymal lineage with more than 100 specific types and many benign potential mimics. In situ and precursor lesions are generally not described and thus much of molecular pathology in this field concentrates on molecular diagnosis, prognosis and determination of therapeutic targets. This chapter discusses the applications of molecular methodologies that provide insight into pathogenesis of sarcoma, and of molecular methods which are currently applied to, or will likely soon influence, the clinical management of this complex array of tumors.
AIDS and agricultural production. Report of a land utilization survey, Masaka and Rakai districts of Uganda.

Abstract Agricultural manpower loss from AIDS in sub-Saharan Africa is being documented in Rwanda, Tanzania and Malawi. In an AIDS-afflicted area of Uganda, one-quarter of families studied had reduced land utilization, crop and livestock production. Reductions were attributed to AIDS mortality and morbidity in 8% of the households. Consequences include increased food insecurity and crisis, and reduced flexibility of response and investment in agro-inputs. AIDS mortality and morbidity will vary microgeographically. Its impact will be most severe in marginal agricultural and ecological zones. Policy makers need to reconsider strategies, to develop planning and monitoring systems, and to encourage programmes to increase labour effectiveness.
An Examination of Aggression and Adaption Traits with Moral Foundation

ABSTRACTMoral Foundation Theory forwards that morality is a traitlike disposition that guides one's behaviors, attitudes, and communication. This study examined the relationship between participants' moral foundations and their aggressive and adaptation communication traits. Results of this study suggest that the foundations that concern others (i.e., harm/care and fairness/reciprocity) were associated negatively to verbal aggressiveness, argumentativeness, and Machiavellianism and associated positively with responsiveness, assertiveness, and cognitive flexibility. The foundations that concern socially binding constructs (i.e., in-group/loyalty, authority/respect, and purity/sanctity) were negatively related to Machiavellianism and cognitive flexibility.
On a class of nonstationary signals

The author is concerned with a class of nonstationary processes described by the piecewise ARMA (autoregressive moving-average) models, whose parameters change abruptly (or jump) at some unknown times. Two different models are examined and the statistics of this type of processes are studied. It is shown that the means of such processes do not depend on the jumps, while the autocovariance functions change gradually after the parameter jump and follow certain interesting patterns. >
The Redshift-Magnitude Relation for Radio Galaxies

We examine the Hubble diagram for radio galaxies and compare radio galaxies and first-ranked cluster galaxies as cosmological test objects. Radio source identification programs are now producing reliable identifications with galaxies as faint as V ≈ 23 and spectroscopy of these objects has already resulted in the discovery of galaxies with redshifts as high as 0. 75, thus there are great expectations for progress in the near future. As in the past, indeterminate corrections, notably luminosity evolution and a possible correlation between radio power and optical luminosity, preclude the determination of qo.
Identification of an α2-Macroglobulin Receptor in Human Mammary Epithelial Cells

Several cases of zinc (Zn) deficiency in human infants caused by abnormally low concentrations of Zn in breast milk were recently reported, the underlying mechanism of which is not known. Alpha2-macroglobulin (alpha2-M), a major Zn-binding ligand in serum, presents a potential vehicle for mammary Zn uptake. This study was conducted to determine if an alpha2-M receptor is present in human mammary epithelial cells, where it may be involved in the endocytosis of alpha2-M into the mammary gland. Normal human mammary epithelial cells were grown to confluency in serum-free medium. For all binding and uptake studies, alpha2-M, preactivated with methylamine and labeled with 125I, was added to cells for varied lengths of time to determine saturation over time and at varied concentrations to determine saturation over increasing concentration of ligand. Nonspecific and competitive binding were measured by addition of a 100-fold molar excess of unlabeled alpha2-M and serum albumin or lactoferrin, respectively. Binding at 4 degreesC was specific for alpha2-M and approached saturation kinetics at 56 nmol/L. Scatchard plot analysis of the binding data demonstrated more than one binding site: a high affinity, saturable binding site and a low affinity, nonsaturable binding site. Uptake of alpha2-M at 37 degreesC was rapid and continuous over increasing concentrations of alpha2-M, and internalized alpha2-M was rapidly degraded. Results from this study present evidence for receptor-mediated uptake of alpha2-M in human mammary epithelial cells, which in turn, provides a potential mechanism for Zn acquisition by the cell.
Evaluation of Nutrient Specifications for Broiler Breeders

Two experiments were conducted to determine if previously suggested nutrient requirements of broiler breeders (23 g protein, 850 mg sulfur amino acids, 4.5 g calcium, and 750 mg phosphorus/bird/day) are in excess and could be reduced during the laying period. In Experiment 1, Cobb color-sex broiler breeders were fed daily nutrient allowances that were 100.0, 96.3, 92.5, 89.4, and 86.6% of the suggested requirements. In Experiment 2, Cobb feather-sex breeders were fed daily allowances that were 92.5, 89.4, 86.6, 83.4, and 80.9% of the suggested requirements. Birds on all diets were fed the same energy level; however, energy varied with season to maintain body weight. Egg production, fertility, hatchability, egg weight, and shell quality were not significantly affected by the reductions in nutrient intake in either experiment. The diet with the lowest nutrient level (80.9% of the suggested requirement) was adequate, indicating a considerable margin of safety for the stated requirements. Body weight was quite variable but tended to decrease with nutrient restriction. Weights of broilers hatched from treated breeders were not significantly affected at 49 days of age by the breeder dietary treatments. These results indicate that broiler breeder diets formulated to meet presently suggested requirements have a large margin of safety and a reduction of specifications by approximately 10% is suggested. The revised daily intakes recommended are: 20.6 g protein, 754 mg sulfur amino acids, 400 mg methionine, 938 mg lysine, 1379 mg arginine, 256 mg tryptophan, 4.07 g calcium, 683 mg total phosphorus, and 170 mg sodium.
Translating clinical evidence to the community: a synopsis and comment on “Community wide interventions for increasing physical activity”

The third column on Evidence-Based Behavioral Medicine is focused on the Baker et al. Cochrane Review entitled “Community wide interventions for increasing physical activity.” We provide a synopsis of the review as well as a comment on the future direction of community-wide physical activity interventions.
Characterization of fluorine'doped silica glasses

Fluorine-doped silica glasses containing up to 2 wt% were prepared by the vapour-phaseaxial-deposition (VAD) sintering process. The characteristics of these glasses were investigated by Raman spectroscopy, vacuum-ultraviolet-ultraviolet (v.u.v-u.v.) spectroscopy, and viscosity measurements. From the Raman spectroscopic investigation, it has been shown that the Si-F bond structure in the fibres is the same as that in bulk glass and is not affected by codoped additives such as B2O3. From the u.v.-v.u.v, spectroscopic investigation, it has been shown that the absorption band at 7.6 eV in high-purity silica glass is removed with the addition of fluorine. This addition produces a silica glass with most excellent transparency in u.v. and v.u.v. regions. Also it was observed that the optimum addition is around 1 wt%. This fact proves that fluorine incorporation in glass prevents the generation of defects related to optical loss in fibres. From the viscosity study, it was found that the viscosity decreases with an increase of the fluorine content in glass and the activation energy also decreases with increasing fluorine content.
THE CELL JUNCTION IN A LAMELLIBRANCH GILL CILIATED EPITHELIUM : Localization of Pyroantimonate Precipitate

The junctional complex in the gill epithelium of the freshwater mussel (Elliptio complanatus) consists of an intermediary junction followed by a 2–3 µ long septate junction. Homologous and heterologous cell pairs are connected by this junction. After fixation with 1% OsO4 containing 1% potassium pyroantimonate, electron microscopy of the gill reveals deposits of electron-opaque precipitate, specifically and consistently localized along cellular membranes. In both junctional and nonjunctional membrane regions, the precipitate usefully outlines the convolutions without obliterating the 150 A intercellular space, which suggests the rarity or absence of either vertebrate-type gap or tight junctions along the entire cell border. The precipitate appears on the cytoplasmic side of the limiting unit membranes of frontal (F), laterofrontal (LF), intermediate (I), lateral (L), and postlateral (PL) cells. The membrane surfaces of certain vesicles of the smooth endoplasmic reticulum, of multivesicular bodies, and of mitochondrial cristae contain precipitate, as does the nucleolus. In other portions of the cell, precipitate is largely absent. The amount of over-all deposition is variable and depends on the treatment of the tissue prior to fixation. Deposition is usually enhanced by pretreatment with 40 mM NaCl as opposed to 40 mM KCl, which suggests that the precipitate is in part sodium pyroantimonate. Treatment with 0.2 mM ouabain does not enhance deposition. Regional differentiation of cell membranes with respect to their ability to precipitate pyroantimonate is found in at least three instances: (a) between the ciliary membranes and other portions of the cell membrane: the precipitate terminates abruptly at the ciliary base, (b) between the LF and I cell borders: the precipitate is asymmetric, favoring the LF side of the junction, and (c) between the septate junctional membrane and adjacent membrane: the precipitate occurs periodically throughout the septate junction region with the periodicity corresponding to the spacing of the septa. This suggests that different regions of the cell membrane may have differing ion permeability properties and, in particular, that the septa may be the regions of high ion permeability in the septate junction.
Alveolar type II cells possess the capability of initiating lung tumor development.

Identifying cells of tumor origin is a fundamental question in tumor biology. Answers to this central question will not only advance our understanding of tumor initiation and progression but also have important therapeutic implications. In this study, we aimed to uncover the cells of origin of lung adenocarcinoma, a major subtype of non-small cell lung cancer. To this end, we developed new mouse models of lung adenocarcinoma that enabled selective manipulation of gene activity in surfactant associated protein C (SPC)-expressing cells, including alveolar type II cells and bronchioalveolar stem cells (BASCs) that reside at the bronchioalveolar duct junction (BADJ). Our findings showed that activation of oncogenic Kras alone or in combination with the removal of the tumor suppressor p53 in SPC+ cells resulted in development of alveolar tumors. Similarly, sustained EGF signaling in SPC+ cells led to alveolar tumors. By contrast, BASCs failed to proliferate or produce tumors under these conditions. Importantly, in a mouse strain in which Kras/p53 activity was selectively altered in type II cells but not BASCs, alveolar tumors developed while BADJs retained normal architecture. These results confirm and extend previous findings and support a model in which lung adenocarcinoma can initiate in alveolar type II cells. Our results establish the foundation for elucidating the molecular mechanisms by which lung cancer initiates and progresses in a specific lung cell type.
Far Ultraviolet Spectral Radiance Calibrations at NBS

The range of NBS radiometric calibration services has been extended into the far ultraviolet region of the spectrum where a dc high-power hydrogen wall-stabilized arc is used as a primary standard of spectral radiance. A capability in the range from 130 to 360 nm (overlapping conventional tungsten strip lamp radiometry) is presently available with estimated uncertainties between 5 and 10%, depending upon wavelength. The status of radiometric source standards in the far ultraviolet is briefly reviewed, and the hydrogen arc and NBS calibration facility are described in detail. The use of commercially available mercury Krefft-Rossler lamps and deuterium arc lamps as transfer or secondary standards is discussed, and the spectra of these lamps calibrated with the hydrogen arc standard are presented.
FIBROBLAST NITROBLUE TETRAZOLIUM TEST AND THE IN-UTERO DIAGNOSIS OF CHRONIC GRANULOMATOUS DISEASE

A quantitative nitroblue tetrazolium (NBT) test was devised to measure dye reduction by fibroblasts. Statistically significant differences were found between NBT reduction by normal skin and amniotic fibroblasts and by skin fibroblasts of male patients with chronic granulomatous disease (CGD) and their carrier relatives. Cultured amniotic cells may therefore be useful in the prenatal diagnosis of X-linked CGD.
Need to Improve Routine HIV Testing of U.S. Veterans in Care: Results of an Internet Survey

Late diagnosis of HIV infection contributes to poor medical outcomes and helps sustain continued transmission of virus. Published evidence suggests that despite current public health recommendations, patients receiving care in the Veterans Health Administration (VHA) system are not being routinely tested for HIV infection. Using a sample of computer-literate veterans, we conducted a survey of recent testing experiences. My HealtheVet (MHV) is a secure website allowing registered Veterans to access limited personal VHA health information. Using the American Customer Satisfaction Index (ACSI) Survey, an electronic questionnaire on “health screening” was conducted in late Fall/early winter 2008–2009. A random sample (4%) of MHV users were surveyed; approximately 17% completed the survey and responses ranged from 31,237 to 33,074. Only 9% of the respondents indicated that they had been offered a test for HIV in the last 12 months compared to 83% who had been offered cholesterol screening, 65% blood sugar screening and 19% who had been offered testing for Hepatitis C virus (HCV). Of those who had been offered HIV testing, 91% indicated that they’d had the test performed. Of note, the percentage of respondents who indicated that they would “very likely” accept a test, if offered, was similar for HIV (73%), HCV (79%), cholesterol (75%), and blood sugar (75%). Although these results cannot be generalized to all Veterans in care, they suggest that routine testing for HIV has not been taking place and support recent VHA policy changes to remove barriers to HIV testing.
Is bird song a reliable signal of aggressive intent

In this commentary, we discuss recent experiments on the reliability of bird song as a signal of aggressive intent during territorial conflicts. We outline relevant theoretical views on honest signaling, highlighting the vulnerability handicap hypothesis as a possible explanation for soft song’s reliability in predicting attack. We also sketch possible methods of testing whether soft song agrees with key predictions of the vulnerability handicap hypothesis. Finally, we suggest possible empirical refinements that may be useful in future studies of signals of intent, both in birds and in animals broadly. In particular, we argue that future studies of intent should strive to incorporate the following elements into their experimental design: (1) multi-modal signal components, (2) interaction dynamics, and (3) minimal time intervals. Simulated exchanges using dynamically interactive models may provide a powerful means of incorporating all three of these design features simultaneously.
Athletic Trainer Perceptions of Life-Work Balance and Parenting Concerns

Context: Life-work balance may be one reason for retention concerns among athletic trainers (ATs), yet evidence does not exist to support the supposition. Objective: To assess the perceptions of AT...
Surgical treatment of greater occipital neuralgia: An appraisal of strategies

The surgical treatment of greater occipital neuralgia often involves diagnostic anesthetic blockade, followed by chemical or surgical ablation of the greater occipital nerve. The anatomy of this region was studied in microdissections of 2 cadaver specimens. The diagnosis and management of a series of 5 patients with greater occipital neuralgia is discussed. Two patients were treated with atlanto-epistrophic ligament decompression of the C 2 dorsal root ganglion and nerve; four patients had C 2 ganglionotomy performed. All patients in this series had immediate complete relief of pain following surgery. Patients were followed for a mean of 24 months (range 7–33 months). One patient had a recurrence of her original pain after 26 months following atlanto-epistrophic ligament decompression and required re-operation in the form of bilateral C 2 ganglionotomy. All patients experienced transient nausea and dizziness in the several days following surgery. One patient had an incisional cerebrospinal fluid leak. Microsurgical C 2 gangliotomy is advocated as the preferred surgical treatment of greater occipital neuralgia of idiopathic origin.
Neuronal synchrony and the transition to spontaneous seizures

The role of inhibitory neuronal activity in the transition to seizure is unclear. On the one hand, seizures are associated with excessive neuronal activity that can spread across the brain, suggesting run-away excitation. On the other hand, recent in vitro studies suggest substantial activity of inhibitory interneurons prior to the onset of evoked seizure-like activity. Yet, little is known about the behavior of interneurons before and during spontaneous seizures in chronic temporal lobe epilepsy. Here, we examined the relationship between the on-going local field potential (LFP) and the activity of populations of hippocampal neurons during the transition to spontaneous seizures in the pilocarpine rat model of epilepsy. Pilocarpine treated rats that exhibited spontaneous seizures were implanted with drivable tetrodes including an LFP electrode and recordings were obtained from the CA3 region. For each recorded seizure, identified single units were classified into putative interneurons or pyramidal cells based on average firing rate, autocorrelation activity and waveform morphology. The onset of sustained ictal spiking, a consistent seizure event that occurred within seconds after the clinically defined seizure onset time, was used to align data from each seizure to a common reference point. Ictal spiking, in this paper, refers to spiking activity in the low-pass filtered LFP during seizures and not the neuronal action potentials. Results show that beginning minutes before the onset of sustained ictal spiking in the local field, subpopulations of putative interneurons displayed a sequence of synchronous behaviors. This includes progressive synchrony with local field oscillations at theta, gamma, and finally ictal spiking frequencies, and an increased firing rate seconds before the onset of ictal spiking. Conversely, putative pyramidal cells did not exhibit increased synchrony or firing rate until after ictal spiking had begun. Our data suggest that the transition to spontaneous seizure in this network is not mediated by increasing excitatory activity, but by distinct changes in the dynamical state of putative interneurons. While these states are not unique for seizure onset, they suggest a series of state transitions that continuously increase the likelihood of a seizure. These data help to interpret the link between in vitro studies demonstrating interneuron activation at the transition to seizure, and human studies demonstrating heterogeneous neuronal firing at this time.
Some Remarks On Remote Sensing And The Earth Resources Survey Program

Robert A. SummersSystem Planning CorporationArlington, VirginiaI would like to welcome all of you to thisafternoon's session on remote sensing and itsapplications. I believe we have a number ofgood papers which illustrate the diversity ofactivity and which are also indicative of the goodquality of work which is going on in the remotesensing and remote sensing applications areas.After having spent the last several years withthe Earth Observation Program at NASA - whichhas provided a unique opportunity to view theentire program throughout government andindustry - I would like to emphasize that I amnow speaking as a private citizen.Let us first consider the goal of the EarthResources Survey (ERS) Program. As most ofus would readily agree, the purpose is not thecollection of data, but is the making of a con-tribution to the intelligent management of ourresources and environment. In this process atotal systems approach must be applied to theproblem and we must aim toward user -orientedsystems which can serve real needs in oursociety from both economic and social viewpoints.
Site-directed Mutagenesis of Arginine 72 of HIV-1 Reverse Transcriptase CATALYTIC ROLE AND INHIBITOR SENSITIVITY

In order to determine the catalytic role of Arg72 of HIV-1 reverse transcriptase (RT), we carried out site-directed mutagenesis at codon 72. Two mutant proteins (R72A and R72K) were purified and characterized. With Arg to Ala substitution the kcat of the polymerase reaction was reduced by nearly 100-fold with poly(rA) template, but only about 5-15-fold with poly(rC) and poly(dC) templates. The Arg to Lys substitution exhibited a qualitatively similar pattern, although the overall reduction in kcat was less severe. Most interestingly, we noted a large difference in the rate constant of the first and second nucleotide incorporation by R72A, suggesting that Arg72 participates in the reaction after the formation of the first phosphodiester bond. We propose this step to be the pyrophosphate binding and removal step following the nucleotidyltransferase reaction. Support for this proposal is obtained from the observation that the R72A mutant (i) exhibited a pronounced translocation defect in the processivity analysis, (ii) lacked the ability to catalyze pyrophosphorolysis, and (iii) showed complete resistance to phosphonoformate, an analog of PPi. Arg72 is the first residue of HIV-1 RT proposed to be involved in the pyrophosphate binding/removal function of RT.
H Is for Enthalpy, Thanks to Heike Kamerlingh Onnes and Alfred W. Porter

During the 19th century the letter H sometimes represented heat, but the designation of enthalpy was placed into the scientific literature in 1909 by J. P. Dalton and credited by him to Heike Kamerlingh Onnes. In 1922 Alfred W. Porter formally proposed that H become the accepted symbol for Kamerlingh Onnes' enthalpy. During the 20th century, however, the genesis of that word became obscured by error, speculation, and use without attribution. This paper resolves current confusion about origins of the word enthalpy and its symbol H by examining their early uses in the literature.
Comment on " Singularity-Free Extraction of a Quaternion from a Direction-Cosine Matrix"

References ^artz, D. R., "A Simple Equation for Rapid Estimation of Rocket Nozzle Convective Heat Transfer Coefficients," Jet Propulsion, Vol. 27, Jan. 1957, pp. 49-51. Bartz, D. R., "Heat Transfer from Rapidly Accelerating Flows," in Advances in Heat Transfer, edited by J. P. Hartnett and T. F. Irvine Jr., Vol. 2, Academic Press, New York, 1965. Cebecci, T. and Smith, A. M. O., Analysis of Turbulent Boundary Layers, Academic Press, New York, 1974. Eckert, E. R. G., Analysis of Heat and Mass Transfer, McGfaw Hill, New York, 1972. Blottner, F. G., ''Finite Difference Methods of Solution of the Boundary Layer Equations," AIAA Journal, Vol. 8, Feb. 1970, pp. 193-205.
Experimental demonstration of accelerated extinction in source‐sink metapopulations

Population extinction is a fundamental ecological process which may be aggravated by the exchange of organisms between productive (source) and unproductive (sink) habitat patches. The extent to which such source-sink exchange affects extinction rates is unknown. We conducted an experiment in which metapopulation effects could be distinguished from source-sink effects in laboratory populations of Daphnia magna. Time-to-extinction in this experiment was maximized at intermediate levels of habitat fragmentation, which is consistent with a minority of theoretical models. These results provided a baseline for comparison with experimental treatments designed to detect effects of concentrating resources in source patches. These treatments showed that source-sink configurations increased population variability (the coefficient of variation in abundance) and extinction hazard compared with homogeneous environments. These results suggest that where environments are spatially heterogeneous, accurate assessments of extinction risk will require understanding the exchange of organisms among population sources and sinks. Such heterogeneity may be the norm rather than the exception because of both the intrinsic heterogeneity naturally exhibited by ecosystems and increasing habitat fragmentation by human activity.
Quantification and characterization of sedimenting particulate organic matter in a shallow hypereutrophic lake

SUMMARY. Sedimenting seston was collected in May-November 1976 and 1977 in sedimentation traps anchored 0.5 m above the pelagic sediments of hypereutrophic Wintergreen Lake. Sedimentation rates differed greatly in the two years studied, ranging from 2.7 to 19.3 g m−2 day−1 in 1976 and from 2.6 to 9.5 g m−2 day−1 in 1977. Because of the shallowness of the lake (maximum depth 6.5 m), the quantity and quality of sedimenting particulate organic matter (POM) was closely linked to the production dynamics of the phytoplankton. Chemical analyses indicated that the sedimenting POM was planktonic in origin and, in contrast to that of many deeper lakes, was dominated by protein. Short sedimentation distances coupled with the close proximity of the anaerobic hypolimnion to the photic zone ensured that the majority of sedimenting POM reached the sediments in a relatively undegraded form.
Relative frequency of nosocomial pathogens at a university hospital during the decade 1980 to 1989

Abstract Background: We compared the relative frequency of pathogens isolated from 1985 to 1989 ( N = 4358) with those isolated from 1980 to 1984 ( N = 5290) in a university hospital to determine trends in the relative importance of pathogens causing nosocomial infection. Methods: Our study was based on surveillance data prospectively obtained between 1980 and 1989 from a 600-bed university hospital. Statistically significant trends occurring from 1980 to 1984 to 1985 to 1989 were determined by x 2 tests with Bonferroni corrections (i.e., p Results: Overall an increased frequency of isolation occurred for Candida and other yeasts and for Haemophilus species . A decreased frequency was noted for Proteus species, non- Bacteroides anaerobes, and Serratia species. Comparison of 1985 to 1989 with 1980 to 1984 revealed that the most significant change in nosocomial pathogens was the marked increase in infections with yeast, principally Candida species. Candida and other yeast infections increased 40%, from 7.6% (rank, 5) to 10.6% (rank, 3) of all pathogens isolated. Increases, which occurred in urine, blood, and wound isolates, were especially marked among surgical patients. In addition, a significant increase was noted among blood isolates in the isolation of yeast other than Candida albicans . Conclusions: We conclude that Candida and other yeasts are being isolated increasingly as causative agents of nosocomial infection.
Wound epithelium resistance controls stump currents

Abstract Following amputation of urodele limbs, large electric currents leave the stump surface. These currents are initially high and decline to low levels within a few days following amputation (R. B. Borgens, M. E. McGinnis, J. W. Vanable, Jr., and E. S. Miles (1984). J. Exp. Zool. 231, 249–256) . Using Notophthalmus viridescens, we examined whether this decrease occurs because of changes in the epidermal battery that drives these currents, or because of an increase in the resistance of the stump current circuit. To do this, we measured the transepithelial potential (TEP) of trunk skin, and the resistance of the developing wound epithelium at intervals after amputation, while also monitoring stump current density. We found that the TEP remains virtually constant, but that the resistance of the wound epithelium increases as the stump currents decrease. Furthermore, when the wound epithelium of stumps with low current densities is gently removed, there is an immediate restoration of stump current density to levels measured immediately after amputation. We conclude that, at least after the first 4 hr, increases in wound epithelium resistance can account for decreases in stump current density. During the first 4 hr after amputation, the analysis is complicated by the possibility that the wound epithelium may not yet be a limiting resistance, and injury currents may be entering the damaged tissue at the stump surface.
Paleohydrologic techniques used to define the spatial occurrence of floods

Abstract Defining the cause and spatial characteristics of floods may be difficult because of limited streamflow and precipitation data. New paleohydrologic techniques that incorporate information from geomorphic, sedimentologic, and botanic studies provide important supplemental information to define homogeneous hydrologic regions. These techniques also help to define the spatial structure of rainstorms and floods and improve regional flood-frequency estimates. The occurrence and the non-occurrence of paleohydrologic evidence of floods, such as flood bars, alluvial fans, and tree scars, provide valuable hydrologic information. The paleohydrologic research to define the spatial characteristics of floods improves the understanding of flood hydrometeorology. This research was used to define the areal extent and contributing drainage area of flash floods in Colorado. Also, paleohydrologic evidence was used to define the spatial boundaries for the Colorado foothills region in terms of the meteorologic cause of flooding and elevation. In general, above 2300 m, peak flows are caused by snowmelt. Below 2300 m, peak flows primarily are caused by rainfall. The foothills region has an upper elevation limit of about 2300 m and a lower elevation limit of about 1500 m. Regional flood-frequency estimates that incorporate the paleohydrologic information indicate that the Big Thompson River flash flood of 1976 had a recurrence interval of approximately 10,000 years. This contrasts markedly with 100 to 300 years determined by using conventional hydrologic analyses. Flood-discharge estimates based on rainfall-runoff methods in the foothills of Colorado result in larger values than those estimated with regional flood-frequency relations, which are based on long-term streamflow data. Preliminary hydrologic and paleohydrologic research indicates that intense rainfall does not occur at higher elevations in other Rocky Mountain states and that the highest elevations for rainfall-producing floods vary by latitude. The study results have implications for floodplain management and design of hydraulic structures in the mountains of Colorado and other Rocky Mountain States.
Transport processes in the renal cortex.

Abstract A mathematical model of the kidney cortex based upon the conservation principles and on the theory of non-equilibrium thermodynamics has been developed. This multi-compartment, multi-component model has been used to describe variations in composition and flow rate in the proximal and distal convoluted tubules and capillaries of the cortex of a typical canine kidney. The simultaneous transport of salt, urea and water has been described under several normal and diuretic conditions, including mannitol diuresis. The simulated mass and volume flows in the tubules were found to be in agreement with experimental data. For example, the model describes isotonic water reabsorption from the proximal tubule in the normal animal and glomerular tubular balance. Values for tubule permeabilities determined from the model parameters were found to be in agreement with published experimental values. In addition we are able to predict kidney performance under a number of diuretic conditions which have not been experimentally verified.
Reintroduction of gene(s) into an attenuated deletion mutant of vaccinia virus strain IHD-W

To evaluate individual genes responsible for virulence of vaccinia virus, a shuttle vector containing a viral fusion fragment from a deletion mutant (Z-19) was constructed. The vector also included a beta-galactosidase cassette which contained the LacZ under the control of the vaccinia late promoter p11 to screen recombinants. The gene in question was reinserted into the attenuated mutant by homologous recombination. The vaccinia growth factor and the vaccinia complement-binding protein genes were inserted into this shuttle vector and transferred by recombination into Z-19. The presence of the inserted gene was examined by Southern hybridization and its expression by Northern blot hybridization. The virulence of the recombinants was investigated by inoculation into mice. Results indicate that the recombinants contained and expressed the inserted gene. Although virulence was recovered, it did not reach the level of the wild-type, either when the recombinant viruses were inoculated alone or in combination. Construction of the shuttle vector allows reintroduction of genes into Z-19 which is completely attenuated in vivo and could be useful as a vaccine vector.