Quark contributions to baryon magnetic moments in full, quenched, and partially quenched QCD

The chiral nonanalytic behavior of quark-flavor contributions to the magnetic moments of octet baryons is determined in full, quenched and partially quenched QCD, using an intuitive and efficient diagrammatic formulation of quenched and partially quenched chiral perturbation theory. The technique provides a separation of quark-sector magnetic-moment contributions into direct sea-quark loop, valence-quark, indirect sea-quark loop and quenched valence contributions, the latter being the conventional view of the quenched approximation. Both meson and baryon mass violations of SU(3)-flavor symmetry are accounted for. Following a comprehensive examination of the individual quark-sector contributions to octet baryon magnetic moments, numerous opportunities to observe and test the underlying structure of baryons and the nature of chiral nonanalytic behavior in QCD and its quenched variants are discussed. In particular, the valence u-quark contribution to the proton magnetic moment provides the optimal opportunity to directly view nonanalytic behavior associated with the meson cloud of full QCD and the quenched meson cloud of quenched QCD. The u quark in Σ+ provides the best opportunity to display the artifacts of the quenched approximation.Derek B. Leinwebe

The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): Illuminating the Functional Diversity of Eukaryotic Life in the Oceans through Transcriptome Sequencing

Microbial ecology is plagued by problems of an abstract nature. Cell sizes are so small and population sizes so large that both are virtually incomprehensible. Niches are so far from our everyday experience as to make their very definition elusive. Organisms that may be abundant and critical to our survival are little understood, seldom described and/or cultured, and sometimes yet to be even seen. One way to confront these problems is to use data of an even more abstract nature: molecular sequence data. Massive environmental nucleic acid sequencing, such as metagenomics or metatranscriptomics, promises functional analysis of microbial communities as a whole, without prior knowledge of which organisms are in the environment or exactly how they are interacting. But sequence-based ecological studies nearly always use a comparative approach, and that requires relevant reference sequences, which are an extremely limited resource when it comes to microbial eukaryotes

Primary demyelination in the central nervous system of cats

Primary demyelinating lesions have been observed in the central nervous system of 16 (approximately 7%) of a total of 235 clinically normal cats. The size of the lesions varied from small perivascular lesions in white matter to a large lesion occupying the diameter of an optic nerve. Intracytoplasmic inclusions consisting of tubular structures were common to all lesions examined by electron microscopy. The features of these feline lesions are briefly compared with those seen in multiple sclerosis

Recovery of viral agents from the central nervous system of cats

Isolation of viruses from the central nervous system (CNS) of cats was attempted using an explant culture technique and subsequent co-cultivation with Crandell feline kidney (CRFK) or Vero cells. Feline syncytia-forming virus was isolated from the CNS of 11 of 16 cats where the initial co-cultivation was with CRFK cells. Feline panleucopaenia virus was isolated from the CNS of 2 adult cats. Co-cultured cells from the CNS of 3 cats contained eosinophilic cytoplasmic and intranuclear inclusions. The cytoplasmic inclusions consisted of tubular structures, 16-18 nm in diameter and up to 500 nm in length, which were similar in morphology to paramyxovirus nucleocapsids. The 3 co-cultured cells with cytoplasmic and intranuclear inclusions showed haemadsorption of guinea pig erythrocytes. The possible identity of these structures, and their association with a previously described primary focal demyelinating lesion in the CNS of cats, is discussed

Detection and prevalence of serotypes of feline syncytial spumaviruses

Three serotypes of feline syncytial virus (FSV) were detected by neutralisation tests: 906, a serotype of low prevalence and 702 and 951 which were serotypes of higher prevalence, between which a minor one-way antigenic difference was detected. Serum antibody in naturally-infected cats in some cases neutralised 951 but not 702 or 906 which suggested that 951 could be considered as a major distinct serotype. An increase in prevalence of antibody to FSV in cats over a 5 year period from 1977–1981 was detected by neutralisation, agar gel immunodiffusion, and fluorescent antibody techniques. Over the 5 year period the prevalence of antibody to the 951 serotype increased and the overall increase in prevalence of antibody to FSV during this period appeared to relate to dissemination of the 951 serotype