Low-lying GT(+) strength in Co-64 studied via the Ni-64(d,He-2)Co-64 reaction

The Ni-64(d,He-2)Co-64 reaction was studied at the AGOR cyclotron of KVI, Groningen, with the Big-Bite Spectrometer and the EuroSuperNova detector using a 171-MeV deuteron beam. An energy resolution of about 110 keV was achieved. In addition to the J(pi) = 1(+) ground state, several other 1(+) states could be identified in Co-64 and the strengths of the corresponding Gamow-Teller transitions were determined. The obtained strength distribution was compared with theoretical predictions and former (n,p) experimental results and displayed a good agreement. Due to the good energy resolution, detailed spectroscopic information was obtained, which supplements the data base needed for network calculations for supernova scenarios

Soils and sediments of the Thua Thien-Hue Province (central Vietnam): recognizing trace element sources and the likely influence of natural events.

Trace element concentrations have been measured in soil and sediment samples taken from the Thua Thien Hue (TT-H) Province and the Tam Giang–Cau Hai (TG–CH) Lagoon in 2002 and 2004. Results show that the lagoon is only slightly contaminated by elements such as Ag, Cd, Cr, Cu, Ni, Pb and Zn, whereas As, probably naturally enriched in this Asian region, reaches values above the lowest internationally accepted sediment quality guidelines. Concentrations in soils are ascribable to natural sources and distributions in the TG–CH Lagoon are mainly influenced by river inputs, with Ag and Cd undergoing estuarine desorption processes. However, concentration–depth profiles of most trace elements in sediments show a recent increasing trend that might be linked to the economic development of the area. The comparison of porosity and 210Pb depth profiles (confirmed also by Cd and As) from repeated samplings of the same core locations in the TG–CH Lagoon seems to account for a loss of 5–10 cm of surficial sediment that took place during the time interval between the two samplings. It is hypothesized that extreme meteorological events (e.g. a major typhoon that hit the area in November 2003) could be responsible for such sediment displacement

Self-reported use of tobacco products in nine rural INDEPTH Health and Demographic Surveillance Systems in Asia

BACKGROUND: Tobacco use is the most preventable cause of premature death and disability. Even though tobacco use is common in many Asian countries, reliable and comparable data on the burden imposed by tobacco use in this region are sparse, and surveillance systems to track trends are in their infancy. OBJECTIVE: To assess and compare the prevalence of tobacco use and its associated factors in nine selected rural sites in five Asian countries. METHODS: Tobacco use among 9,208 men and 9,221 women aged 25-64 years in nine Health and Demographic Surveillance System (HDSS) sites in five Asian countries of the INDEPTH Network were examined in 2005 as part of a broader survey of the major chronic non-communicable disease risk factors. All sites used a standardised protocol based on the WHO STEPS approach to risk factor surveillance; expanded questions of local relevance, including chewing tobacco, were also included. Multivariable logistic regression was used to assess demographic factors associated with tobacco use. RESULTS: Tobacco use, whether smoked or chewed, was common across all sites with some notable variations. More than 50% of men smoked daily; this applied to almost all age groups. Few women smoked daily in any of the sites. However, women were more likely to chew tobacco than men in all sites except Vadu in India. Tobacco use in men began in late adolescence in most of the sites and the number of cigarettes smoked daily ranged from three to 15. Use of both forms of tobacco, smoked and chewed, was associated with age, gender and education. Men were more likely to smoke compared to women, smoking increased with age in the four sites in Bangladesh but not in other sites and with low level of education in all the sites. CONCLUSION: The prevalence of tobacco use, regardless of the type of tobacco, was high among men in all of these rural populations with tobacco use started during adolescence in all HDSS sites. Innovative communication strategies for behaviour change targeting adolescents in schools and adult men and women at work or at home, may create a mass awareness about adverse health consequences of tobacco smoking or chewing tobacco. Such efforts, to be effective, however, need to be supported by strong legislation and leadership. Only four of the five countries involved in this multi-site study have ratified the Framework Convention on Tobacco Control, and even where it has been ratified, implementation is uneven.Supplement: 1</p

Low pH immobilizes and kills human leukocytes and prevents transmission of cell-associated HIV in a mouse model

BACKGROUND: Both cell-associated and cell-free HIV virions are present in semen and cervical secretions of HIV-infected individuals. Thus, topical microbicides may need to inactivate both cell-associated and cell-free HIV to prevent sexual transmission of HIV/AIDS. To determine if the mild acidity of the healthy vagina and acid buffering microbicides would prevent transmission by HIV-infected leukocytes, we measured the effect of pH on leukocyte motility, viability and intracellular pH and tested the ability of an acidic buffering microbicide (BufferGel(®)) to prevent the transmission of cell-associated HIV in a HuPBL-SCID mouse model. METHODS: Human lymphocyte, monocyte, and macrophage motilities were measured as a function of time and pH using various acidifying agents. Lymphocyte and macrophage motilities were measured using video microscopy. Monocyte motility was measured using video microscopy and chemotactic chambers. Peripheral blood mononuclear cell (PBMC) viability and intracellular pH were determined as a function of time and pH using fluorescent dyes. HuPBL-SCID mice were pretreated with BufferGel, saline, or a control gel and challenged with HIV-1-infected human PBMCs. RESULTS: Progressive motility was completely abolished in all cell types between pH 5.5 and 6.0. Concomitantly, at and below pH 5.5, the intracellular pH of PBMCs dropped precipitously to match the extracellular medium and did not recover. After acidification with hydrochloric acid to pH 4.5 for 60 min, although completely immotile, 58% of PBMCs excluded ethidium homodimer-1 (dead-cell dye). In contrast, when acidified to this pH with BufferGel, a microbicide designed to maintain vaginal acidity in the presence of semen, only 4% excluded dye at 10 min and none excluded dye after 30 min. BufferGel significantly reduced transmission of HIV-1 in HuPBL-SCID mice (1 of 12 infected) compared to saline (12 of 12 infected) and a control gel (5 of 7 infected). CONCLUSION: These results suggest that physiologic or microbicide-induced acid immobilization and killing of infected white blood cells may be effective in preventing sexual transmission of cell-associated HIV

Bulk vs. Surface Structure of 3d Metal Impurities in Topological Insulator Bi2Te3

AbstractTopological insulators have become one of the most prominent research topics in materials science in recent years. Specifically, Bi2Te3 is one of the most promising for technological applications due to its conductive surface states and insulating bulk properties. Herein, we contrast the bulk and surface structural environments of dopant ions Cr, Mn, Fe, Co, Ni, and Cu in Bi2Te3 thin films in order to further elucidate this compound. Our measurements show the preferred oxidation state and surrounding crystal environment of each 3d-metal atomic species, and how they are incorporated into Bi2Te3. We show that in each case there is a unique interplay between structural environments, and that it is highly dependant on the dopant atom. Mn impurities in Bi2Te3 purely substitute into Bi sites in a 2+ oxidation state. Cr atoms seem only to reside on the surface and are effectively not able to be absorbed into the bulk. Whereas for Co and Ni, an array of substitutional, interstitial, and metallic configurations occur. Considering the relatively heavy Cu atoms, metallic clusters are highly favourable. The situation with Fe is even more complex, displaying a mix of oxidation states that differ greatly between the surface and bulk environments.</jats:p

Direct proton decay of the isoscalar giant dipole resonance

The direct proton decay of the isoscalar giant dipole resonance (ISGDR) has been studied in Pb-208 using the (alpha,alpha' p) reaction at a bombarding energy of 200 MeV Through observation of direct-decay protons from the ISGDR in coincidence with scattered a-particles, the population of proton-hole states in Tl-207 was studied, allowing us to test recently performed continuum-RPA (CRPA) calculations for the ISGDR and thereby to learn about its microscopic structure. The energy and width of the ISGDR were also determined to be 22.1 +/- 0.3 MeV and 3.8 +/- 0.8 MeV, respectively. A new resonance of quadrupole character was observed at E-x = 26.9 +/- 0.7 MeV with a width of 6.0 +/- 1.3 MeV

The lag-phase during diauxic growth is a trade-off between fast adaptation and high growth rate

Bi-phasic or diauxic growth is often observed when microbes are grown in a chemically defined medium containing two sugars (for example glucose and lactose). Typically, the two growth stages are separated by an often lengthy phase of arrested growth, the so-called lag-phase. Diauxic growth is usually interpreted as an adaptation to maximise population growth in multi-nutrient environments. However, the lag-phase implies a substantial loss of growth during the switch-over. It therefore remains unexplained why the lag-phase is adaptive. Here we show by means of a stochastic simulation model based on the bacterial PTS system that it is not possible to shorten the lag-phase without incurring a permanent growth-penalty. Mechanistically, this is due to the inherent and well established limitations of biological sensors to operate efficiently at a given resource cost. Hence, there is a trade-off between lost growth during the diauxic switch and the long-term growth potential of the cell. Using simulated evolution we predict that the lag-phase will evolve depending on the distribution of conditions experienced during adaptation. In environments where switching is less frequently required, the lag-phase will evolve to be longer whereas, in frequently changing environments, the lag-phase will evolve to be shorter

Energy-efficient precoding in multicell networks with full-duplex base stations

© 2017, The Author(s). This paper considers multi-input multi-output (MIMO) multicell networks, where the base stations (BSs) are full-duplex transceivers, while uplink and downlink users are equipped with multiple antennas and operate in a half-duplex mode. The problem of interest is to design linear precoders for BSs and users to optimize the network’s energy efficiency. Given that the energy efficiency objective is not a ratio of concave and convex functions, the commonly used Dinkelbach-type algorithms are not applicable. We develop a low-complexity path-following algorithm that only invokes one simple convex quadratic program at each iteration, which converges at least to the local optimum. Numerical results demonstrate the performance advantage of our proposed algorithm in terms of energy efficiency

A Bayesian approach to quantifying the effects of mass poultry vaccination upon the spatial and temporal dynamics of H5N1 in Northern Vietnam.

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