An investigation of the lactic acid bacteria

It has proved difficult, in this laboratory, to identify the lactic acid bacteria isolated from silage according to the present system of classification. Keddie(1959) stressed this difficulty by his description of a number of lactobacilli isolated from silage, many of which were unidentifiable or apparently atypical of recognized species. Whittenbury(1960) found the same was true of streptococci and leuconostocs isolated from fresh grass and silage. This investigation, a series of studies on lactic acid bacteria isolated from fresh herbage and silage, aims at clarifying this situation. A number of named strains were also examined to assess the relationship of the silage organisms to the known species. This necessitated a general study of the various genera.This thesis is composed of six sections. The first concerns the reaction of various types of lactic acid bacteria to aerobic and anaerobic environments. The next four sections comprise studies on the classification of enterococci, pediococci, leuconostocs and heterofermentative lactobacilli. The final section is mainly of an applied nature and deals with aspects related to the production of silage

Quark-Meson Coupling model based upon the Nambu-Jona Lasinio model

The NJL model for the octet baryons, using proper time regularization to simulate some of the features of confinement, is solved self-consistently in nuclear matter. This provides an alternative framework to the MIT bag model which has been used in the quark-meson coupling model. After fitting the parameters of the model to the saturation properties of symmetric nuclear matter the model is used to explore the equation of state of pure neutron matter as well as nuclear matter at densities relevant to heavy ion collisions. With a view to future studies of high mass neutron stars, the binding of hyperons is also explored.Comment: 7 pages and 4 figure

Neutron Star Properties with Hyperons

In the light of the recent discovery of a neutron star with a mass accurately determined to be almost two solar masses, it has been suggested that hyperons cannot play a role in the equation of state of dense matter in $\beta$-equilibrium. We re-examine this issue in the most recent development of the quark-meson coupling model. Within a relativistic Hartree-Fock approach and including the full tensor structure at the vector-meson-baryon vertices, we find that not only must hyperons appear in matter at the densities relevant to such a massive star but that the maximum mass predicted is completely consistent with the observation.Comment: Minor correction

A Capacitance Probe for Recording Water Waves

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669

Wind Waves on the Water

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-56695, D/A Sub-Task 3-99-06-11

Diversity of methyl halide-degrading microorganisms in oceanic and coastal waters

Methyl halides have a significant impact on atmospheric chemistry, particularly in the degradation of stratospheric ozone. Bacteria are known to contribute to the degradation of methyl halides in the oceans and marine bacteria capable of using methyl bromide and methyl chloride as sole carbon and energy source have been isolated. A genetic marker for microbial degradation of methyl bromide ( cmuA ) was used to examine the distribution and diversity of these organisms in the marine environment. Three novel marine clades of cmuA were identified in unamended seawater and in marine enrichment cultures degrading methyl halides. Two of these cmuA clades are not represented in extant bacteria, demonstrating the utility of this molecular marker in identifying uncultivated marine methyl halide-degrading bacteria. The detection of populations of marine bacteria containing cmuA genes suggests that marine bacteria employing the CmuA enzyme contribute to methyl halide cycling in the ocean

EoS for massive neutron stars

Using relativistic Hartree-Fock approximation, we investigate the properties of the neutron-star matter in detail. In the present calculation, we consider not only the tensor coupling of vector mesons to octet baryons and the form factors at interaction vertexes but also the internal (quark) structure change of baryons in dense matter. The relativistic Hartree-Fock calculations are performed in two ways: one is the calculation with the coupling constants determined by SU(6) (quark model) symmetry, the other is with the coupling constants based on SU(3) (flavor) symmetry. For the latter case, we use the latest Nijmegen (ESC08) model. Then, it is very remarkable that the particle composition of the core matter in SU(3) symmetry is completely different from that in SU(6) symmetry. In SU(6) symmetry, all octet baryons appear in the density region below $\sim 1.2$ fm$^{-3}$, while, in the ESC08 model, only the \Xi^- hyperon is produced. Furthermore, the medium modification of the internal baryon structure hardens the equation of state for the core matter. Taking all these effects into account, we can obtain the maximum neutron-star mass which is consistent with the recently observed mass, 1.97 \pm 0.04 M_\sun (PSR J1614-2230). We therefore conclude that the extension from SU(6) symmetry to SU(3) symmetry in the meson-baryon couplings and the internal baryon-structure variation in matter certainly enhance the mass of neutron star. Furthermore, the effects of the form factor at vertex and the Fock contribution including the tensor coupling due to the vector mesons are indispensable to describe the core matter. In particular, the Fock term is very vital in reproducing the preferable value of symmetry energy, a_4 (\simeq 30 - 40 MeV), in nuclear matter.Comment: 10 figures, 8 table

Young People and Mental Health: How do young people want mental health support to be delivered?

In this article, Kim Heyes, Elaine Craig, Paul Gray, Kate Whittenbury, Lauren Barclay and Jessica Leigh (a group of researchers and young people) draw on a recent consultation to argue that the current system of mental health support for young people is broken