Search Results - (Author, Cooperation:R. Terry)

2015-12-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Agriculture/*history ; Animals ; *Ecosystem ; History, Ancient ; Human Activities/*history ; Humans ; North America ; *Plant Physiological Phenomena ; Population Dynamics ; Time Factors

2014-03-01

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Base Sequence ; Cell Line ; Cells, Cultured ; DNA, Complementary ; Fluorescence ; Gene Expression Profiling/*methods ; Humans ; Induced Pluripotent Stem Cells ; RNA, Messenger/genetics/metabolism ; Sequence Analysis, RNA/*methods ; Single-Cell Analysis ; Transcription Initiation Site ; *Transcriptome ; Wound Healing

1360-0443

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Psychology

Aims. Drug scenes (social and spatial drug-using and drug-selling environments) have complex role structures. Many drug injectors earn money or drugs as drug or syringe sellers, hit doctors (people who help others to inject) commercial sex workers, or in other roles. This paper aims to measure "role behaviors" of drug injectors; describe which drug injectors are more likely to engage in such role behaviors; and to determine whether roles are related to elements of HIV risk . Design. Cross-sectional study of drug injectors . Setting. Bushwick, a section of Brooklyn, New York, a major location for injection drug use and drug sales . Participants. Seven hundred and sixty-seven street-recruited drug injectors . Measurements. Participants were interviewed about their roles, behaviors, socio-demographics and risk networks; sera were collected and assayed for HIV and hepatitis B core antibody . Findings. Socio-demographic variables are related to role-holding in complex ways. Economic need is generally associated with engaging in drug-scene role behaviors. Holders of these roles are at greater behavioral and network risk for HIV and other blood-borne infections than are other drug injectors. They also engage in extensive communication with other drug users, including discussion of HIV risk reduction . Conclusion. Role behaviors can be measured in quantitative studies, and seem to be related to HIV risk. Role-holders may be strategic targets for risk-reduction campaigns. It seems feasible and advisable to measure drug scene role-holding in research on drug users.

Electronic Resource

1360-0443

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Psychology

Aims  Prompted by the history of heroin diffusion in the United States, press reports and building on previous research into retail heroin distribution, ethnographic research was undertaken identifying and describing retail distribution and diffusion of heroin in and into medium- and small-sized towns in the mid-Hudson region of New York State.Methods  In conjunction with fieldwork, in-depth tape-recorded interviews were conducted with recent admissions (30 days) at 28 different drug treatment facilities located in the region. Interviews were also conducted with drug counselors, narcotic officers, drug treatment administrators and the county commissioners of mental hygiene.Findings  Heroin-dependent individuals who have access to cheaper heroin in urban areas, such as New York City, Newark, and Patterson, New Jersey, drive retail heroin distribution in the mid-Hudson region. They travel to these cities, purchase heroin in quantity (costing $8–10 per bag), return to the region and sell premium-priced heroin ($20-$25 per bag) mostly to irregular users who do not have access to retail drug sellers in urban areas.Conclusion  Price disparity contributes to a recurrent process whereby irregular users who are able to gain access to cheaper heroin in urban areas, return to the mid-Hudson and sell premium-priced heroin to other users who do not have access to cheaper heroin. This process contributes to the diffusion of heroin abuse.

Electronic Resource

1572-879X

furfural hydrogenation ; Cu/carbon catalysts ; kinetics

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Furfural hydrogenation over copper dispersed on three forms of carbon – activated carbon, diamond and graphitized fibers – were studied. Only hydrogenation of the C=O bond to form either furfuryl alcohol or 2‐methyl furan occurred at temperatures from 473 to 573 K. Reduction at 573 K gave the most active catalysts, all three catalysts had activation energies of 16 kcal/mol, and turnover frequencies were 0.018–0.032 s-1 based on the number of Cu0 + Cu+ sites, which were counted by N2O adsorption at 363 K and CO adsorption at 300 K, respectively. The Cu/activated carbon catalyst showed no deactivation during 10 h on stream, in contrast to the other two catalysts. A simple Langmuir–Hinshelwood model invoking two types of sites was able to fit all kinetic data quite satisfactorily, thus it was consistent with the presence of both Cu0 and Cu+ sites.

Electronic Resource

0190-292X

Political Science

1432-2056

Springer Online Journal Archives 1860-2000

Biology

Abstract Approximately 8 years after the Exxon Valdez oil spill, river otters (Lutra canadensis) were trapped from the shoreline in both oiled (Knight Island) and nonoiled (Jackpot Bay) areas of Prince William Sound, Alaska. Captive river otters were wiped with isopropanol-soaked gauze and the gauze extracts were analyzed by gas chromatography with mass spectrometry detection. Differences in pentacosane (C-25) levels in the fur were observed between the oiled and nonoiled sites, while lower molecular weight aliphatics and aromatics were absent. These data are useful when evaluating the role of fur grooming in the long-term exposure of river otters to hydrocarbons and the expression of P450-1A in Knight Island otters.

Electronic Resource

1432-1939

Alces alces ; Moose ; Nutrient cycling ; Salix ; Willow

Springer Online Journal Archives 1860-2000

Biology

Abstract Moose (Alces alces) browsing on diamondleaf willow (Salix planifolia pulchra) caused significant increases in subsequent growth of stems and leaves in treeline plant communities in central Alaska, USA. Willows growing in the shade were significantly more palatable for moose than those growing in the sun. Moose density had strong effects on rates of nutrient cycling, ostensibly through effects of browsing and inputs from fecal and urinary nitrogen. Moose are a keystone herbivore that likely mediate rates of nutrient cycling in northern ecosystems.

Electronic Resource

1439-6327

Key words Lateral gastrocnemius ; Citrate synthase ; Ageing ; 31P-MRS ; Oxidative capacity

Springer Online Journal Archives 1860-2000

Medicine

Abstract The purpose of this study was to compare muscle oxidative capacity between moderately active young and old humans by measuring intracellular threshold (IT) during exercise with 31P-magnetic resonance spectroscopy (31P-MRS). Changes in phosphocreatine, inorganic phosphate, and intracellular pH were measured by 31P-MRS during a progressive unilateral ankle plantar flexion exercise protocol in groups of moderately active old (n=12, mean age 66.7 years) and young (n=13, mean age 26.2 years) individuals. From muscle biopsy samples of the lateral gastrocnemius, citrate synthase (CS) activity was determined in six subjects from each group, and fibre type composition was determined in nine old and ten young subjects. The old group had a lower IT for pH, as a percentage of peak work rate (P〈0.05), despite a similar CS activity compared to the young. IT was significantly correlated with CS activity (R=0.59; P〈0.05), but not with fibre type composition. It was concluded that metabolic responses to exercise are affected by ageing, as indicated by a lower IT in old compared to young individuals.

Electronic Resource

1573-1561

Alces alces gigas ; Alaskan moose ; pheromones ; urine ; mating behavior ; honest advertisement

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract We tested hypotheses about how olfactory communication was related to mating behavior in Alaskan moose (Alces alces gigas). Males dig rutting pits where they deposit odiferous urine; females are strongly attracted to and often wallow in those pits. Moreover, mating and parturition are highly synchronized in moose. Consequently, male urine may play an important role in the mating system and in synchronizing reproduction in moose. Urine samples were collected from captive moose on the Kenai Peninsula, Alaska. Samples included those from the mating season and from the nonrutting period for two adult males, one yearling male, and one male and one female less than 1 year old. After pH adjustment, samples were extracted with methylene chloride to yield three fractions (acidic, neutral, and basic), which were analyzed by gas chromatography–mass spectrometry. Potential pheromones included unsaturated alcohols and homologs of tetrahydro-6-methyl pyranone and 2-nonen-4-one. We hypothesize that these compounds are related to hypophagia and catabolism of body reserves by rutting males, and thereby provide an honest advertisement of body condition by male moose during the mating season.

Electronic Resource

1572-9702

Springer Online Journal Archives 1860-2000

Biology

Abstract Primary attachment sites of male, female, and nymphalAmblyomma americanum (L.) on nursing beef calves were the axillary, inguinal and perianal areas of the body. About 50% of all larvae fed on the ears. A density assessment method which uses the number ofA. americanum on ≤5 body areas to predict the total number of ticks (tick burden) on the left side of a calf is presented. Estimates of tick burden for male, female, nymphal and larvalA. americanum each require examination of the axillary, inguinal, and perianal body areas. In addition, to estimate larval and maleA. americanum, the neck, dewlap and brisket require examination as do the ears for estimates of nymphs and larvae. Mean tick burden in a herd of calves can be estimated by an examination of from 14 to 100% of all calves depending on the level of precision required for the estimate.

Electronic Resource

book

1989

English

2018-01-12

BMJ Publishing

2044-6055

Medicine

Open access, General practice / Family practice

2018-08-02

Cold Spring Harbor Laboratory Press

0890-9369

Biology

1089-7550

AIP Digital Archive

Physics

This paper describes the injection and trapping of a high-current space-charge-dominated electron beam into a closed cyclic accelerator. A method has been developed to transport externally generated beams into a strong-focusing betatron using a pulsed E×B drift. The method requires modest electric fields, gives good trapping efficiency, provides continuous focusing of high-perveance beams, has tolerance to imperfections, and has the potential ability to maintain the emittance of the injected beam. The accelerator was a racetrack machine with an 8-m circumference. Forty solenoid coils with alternating field polarity provided strong focusing. The 220-A, 500-keV injected beam entered the machine through a 2.5-cm-diam shielded transport tube. A pulsed electric field captured a 30-ns slice of the beam− the system trapped most of the current that had completed a full circuit. The main problem encountered in the experiments was a rapid loss of beam electrons during and after trapping. Electrons traveled an average of only two revolutions (16 m). Experimental observations and theoretical studies implied that magnetic dipole field errors in the injector were the primary cause of beam loss.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

This paper reports theoretical and experimental work on the transport of space-charge-dominated relativistic electron beams in a racetrack betatron with cusp focusing. High-efficiency propagation of 550-keV, 280-A beams through a complex optical system consisting of two 180° arcs with 36 focusing cells and a straight section was observed. More than 90% of the injected beam was captured and transported through the 7-m system. The experiments resolved several recent problems of beam injection and trapping in the machine and showed that electron beam transport at the space-charge limit is possible in a curved cusp array despite strong axial variations of focusing forces. We encountered no problems with the transitions between curved and straight focusing sections. The experiments demonstrated good beam containment in a cusp array with mixed focusing cell geometries as long as the axially averaged focusing force was the same for all cells. The ability to use long cells is a critical feasibility issue for other planned injection experiments into a closed racetrack geometry.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The pseudospectral (PS) method for self-consistent-field calculations is extended for use in generalized valence-bond calculations and is used to calculate singlet–triplet excitation energies in methylene, silylene, and ethylene molecules and bond dissociation and twisting energies in ethylene. We find that the PS calculations lead to an accuracy in total energies of ≤0.1 kcal/mol and excitation energies to ≤0.01 kcal/mol for all systems. With effective core potentials on Si, we find greatly improved accuracy for PS.

Electronic Resource

1089-7674

AIP Digital Archive

Physics

The microstability of electrostatic waves in the periphery of a Z pinch is formulated and resolved for a new class of Vlasov meta-equilibria admitting self-similar solutions in the electron gyrokinetic limit. These equilibria are subject to strong radial motions, and a mild deviation from charge neutrality arises to maintain ion acceleration close to that of the magnetized electrons. A unique class of profiles in density, axial current, temperature, and drift speed defines these equilibria. They are characterized by (i) the interior pinch current, (ii) the interior number density, (iii) the parallel and perpendicular temperatures, (iv) the exterior axial electric field value at the initial time, and (v) the radial ion acceleration relative to that of the electrons. Unstable ion sound waves arise in this medium by coupling radial and axial free energy to azimuthal longitudinal oscillations. The waves grow only for a limited range of radial or axial E×bˆ/B drift speeds and electron temperatures. The growth rate, which can be as large as 0.115ωpi, is found to scale proportional to plasma frequency over the density range from 1012 to 1018 ions cm−3.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Molecular dynamics simulations of water above a lipid (dimyristoylphosphatidylcholine) monolayer show that the structure and dynamics of the water are quite sensitive to the treatment of the long range forces. To obtain a quantitative estimate of the perturbations introduced into the water behavior by truncation of the potential, we calculate various structural and dynamical properties of the water for simulations employing different cutoffs. When potential cutoffs on the order of 10–14 A(ring) are employed, the properties of water near the monolayer exhibit perturbations of up to 20%–25% that extend 30–35 A(ring) into the water. Employing cutoffs on the order of 30 A(ring) leads to water behavior that is essentially uniform above the monolayer. We also present a quantitative description of the difference in the force experienced by individual atoms in simulations employing different cutoffs. Despite the significant difference in the water properties between simulations employing 14 A(ring) and effective 30 A(ring) cutoffs, the forces on the individual atoms differ by only ∼1%. It was also found that the motion of the lipids did not significantly affect the perturbations in the water properties. Simulations with shorter cutoffs in which the lipid atomic point charges were set to zero showed no perturbation in water structure. Water adjacent to a repulsive wall employed to maintain the system density also exhibited different behavior with effective 30 A(ring) cutoffs than with 14 A(ring) cutoffs.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

We report molecular dynamics simulations of water hydrating a lipid (dimyristoylphosphatidylcholine) monolayer under conditions chosen to eliminate simulation artifacts. These simulations provide a description of the behavior of the membrane–water interface that agrees with recent experimental studies. In particular, we find that the hydrating water orients to contribute the positive end of its dipole to the substantially positive electrostatic potential of the membrane interior, consistent with interpretations of recent experiments. In addition, recent experiments show that this water reorients rapidly on the NMR time scale. Our results concur, however the relatively rapid water motion does not preclude the preferential ordering that we observe. The limiting behavior of the system shows three hydration shells about the lipid PC headgroups and significant hydrogen bonding of water to the phosphate groups. The choline group experiences different environments, and the structure of the first hydration shell clearly corresponds to a clathrate. The motion of the hydrating water was found to be slower than that of bulk water, and the computed residence times for water about the lipids (20 ps about choline, 10 ps about phosphate) were in excellent agreement with results of NMR experiments. This further shows that water resides in a clathrate shell longer than in a shell about ions. In addition, we show that the structure and dynamics of water hydrating the lipids are very sensitive to the treatment of the long-range interactions. In particular, the radial structure sharpens considerably, a third hydration shell about the phosphate was observed only with large cutoffs, and hydrogen bonding of water to the lipids increased by 25%. The water moved more slowly than bulk when large cutoffs were employed but moved faster than bulk water when small cutoffs were used and the residence times for water about the lipids were twofold–fivefold larger using large cutoffs. In general it was found that the lipids significantly influence water out to several hydration shells, and that water hydrating the lipids behaves differently than bulk water.

Electronic Resource