Production of butanol by fermentation in the presence of cocultures of clostridium

Sugars are converted to a mixture of solvents including butanol by a fermentation process employing a coculture of microorganisms of the Clostridium genus, one of said microorganisms favoring the production of butyric acid and the other of which converts the butyric acid so produced to butanol. The use of a coculture substantially increases the yield of butanol over that obtained using a culture employing only one microorganism

Quantitative ultraviolet measurements on wetted thin-layer chromatography plates using a charge-coupled device camera

This paper presents the first study of the UV imaging of spots on thin-layer chromatographic plates whilst still wet with solvent. Imaging of spots of benzophenone during and after development was carried out using a charge-coupled device camera. Limits of detection were found to be 5 ng on a wetted plate and 3 ng for a dry plate and the relationship between peak area and sample loading was found to be linear in the low nanograrn range over an order of magnitude for both wet and dry modes with r(2) values > 0.99. It was found that UV measurements on wet glass-backed plates suffer from low sensitivity; however, the use of aluminium-backed plates gave increased sensitivity. The apparent absorption coefficient (epsilon(app)) of 10AU m(2) g(-1) at 254 nm is consistent with reflection of the light from the aluminium surface with a double pass through the sorbent layer, and suggests that use of aluminium-backed plates should enable monitoring of separations by UV absorbance during TLC development. (c) 2008 Elsevier B.V. All rights reserved

Pathogen burden and cortisol profiles over the day

Hypothalamic-pituitary-adrenocortical (HPA) regulation in adults is influenced by early psychosocial adversity, but the role of infectious disease history is poorly understood. We studied the association between cumulative pathogen burden and cortisol profile over the day in a sample of 317 healthy men and women aged 51-72 years. Cumulative pathogen burden was defined as positive serostatus for Chlamydia pneumoniae, cytomegalovirus (CMV) and herpes simplex virus 1 (HSV-1). Salivary cortisol was sampled repeatedly over the day. The cortisol slope was defined as the decrease across the day and evening. Age, gender, grade of employment, body mass index, smoking status, self-rated health, cardiovascular medication, depressed mood and time of waking were included as covariates. The pathogen burden averaged 1.76 (S.D. = 0.92). The cortisol slope was inversely associated with pathogen burden after controlling for covariates. When individual pathogens were studied, only CMV was associated with flatter cortisol rhythms in isolation. We conclude that pathogen burden is independently associated with flatter cortisol slopes over the day, and may contribute to disturbed neuroendocrine regulation

Looking for a light Higgs boson in the overlooked channel

The final state obtained when a Higgs boson decays to a photon and a Z boson has been mostly overlooked in current searches for a light Higgs boson. However, when the Z boson decays leptonically, all final state particles in this channel can be measured, allowing for accurate reconstructions of the Higgs mass and angular correlations. We determine the sensitivity of the Large Hadron Collider (LHC) running at center of masses energies of 8 and 14 TeV to Standard Model (SM) Higgs bosons with masses in the 120 - 130 GeV range. For the 8 TeV LHC, sensitivity to several times the the SM cross section times branching ratio may be obtained with 20 inverse femtobarns of integrated luminosity, while for the 14 TeV LHC, the SM rate is probed with about 100 inverse femtobarns of integrated luminosity.Comment: 4 pages, 4 figures. Improves on version 1 in that 8 and 14 TeV LHC running is considered, the case of a 125 GeV Higgs is treated specifically, and the effect of an additional jet in the final state has been taken into account in studying experimental sensitivit

Middle-Upper Ordovician conodonts from the Ffairfach and Golden Grove groups in South Wales, United Kingdom

The conodont fauna of the reference succession of the regional British Llandeilian Stage of the Llanvirn Series was first described in a classical study by Rhodes more than 65 years ago using single element (form) taxonomy. Although several subsequent authors have recorded a substantial number of conodont taxa from the Llandeilo area, the present study is the first to present a modern taxonomic review of these late Darriwilian-early Sandbian faunas that include approximately 20 multielement species. Most prominent are representatives of Amorphognathus, Baltoniodus, Eoplacognathus, and Plectodina. The study faunas have their own biogeographical character. The distinctive genera Complexodus, Protopanderodus, and Pygodus, which are common in coeval Baltoscandic faunas, are not present, but the occurrence of Amorphognathus, Baltoniodus, and Eoplacognathus provides a link to age equivalent Baltoscandic faunas. The presence of abundant specimens of Plectodina and less common representatives of Erismodus and Icriodella are reminiscent of North American Midcontinent faunas. This type of faunal assemblage is in some respects similar to those of the early Caradoc Series of the Welsh Borderland. Biostratigraphically diagnostic species indicate that the Llandeilo study succession ranges from the Eoplacognathus lindstroemi Subzone of the Pygodus serra Zone to the Baltoniodus variabilis Subzone of the Amorphognathus tvaerensis Zone

A proposed new policy for planetary protection

A critical review of the present policy was conducted with emphasis on its application to future planetary exploration. The probable impact of recent data on the implementation of the present policy was also assessed. The existing policy and its implementation were found to: be excessive for certain missions (e.g., Voyager), neglect the contamination hazard posed by the bulk constituent organics of spacecraft, be ambiguous for certain missions (e.g., Pioneer Venus), and treat all extraterrestrial sample return missions alike. The major features of the proposed policy are planet/mission combinations, a qualitative top level statement, and implementation by exception rather than rule. The concept of planet/mission categories permits the imposition of requirements according to both biological interest in the target planet and the relative contamination hazard of the mission type

Kinetic decoupling of neutralino dark matter

After neutralinos cease annihilating in the early Universe, they may still scatter elastically from other particles in the primordial plasma. At some point in time, however, they will eventually stop scattering. We calculate the cross sections for neutralino elastic scattering from standard-model particles to determine the time at which this kinetic decoupling occurs. We show that kinetic decoupling occurs above a temperature $T\sim$ MeV. Thereafter, neutralinos act as collisionless cold dark matter.Comment: Replaced with revised version, new references adde

Microscopic calculation of 6Li elastic and transition form factors

Variational Monte Carlo wave functions, obtained from a realistic Hamiltonian consisting of the Argonne v18 two-nucleon and Urbana-IX three-nucleon interactions, are used to calculate the 6Li ground-state longitudinal and transverse form factors as well as transition form factors to the first four excited states. The charge and current operators include one- and two-body components, leading terms of which are constructed consistently with the two-nucleon interaction. The calculated form factors and radiative widths are in good agreement with available experimental data.Comment: 9 pages, 2 figures, REVTeX, submitted to Physical Review Letters, with updated introduction and reference