16 research outputs found
Isoperimetric Regions in Gauss Sectors
We consider the free boundary isoperimetric problem in sectors of the Gauss plane. The solution is not always a circular arc as in sectors of the Euclidean plane. We prove that the solution is sometimes a ray and we conjecture that the solution is sometimes a rounded n-gon which we discovered computationally using Mathematica
Effects of CCK in the Nucleus Accumbens on Da-Induced Locomotion: Tilt Cage and Rotometer Measures
In Psycho-Spiritual Integrative Therapy for Women with Primary Breast Cancer, What Factors Account for the Benefits? Insights from a Multiple Case Analysis
This study sought to understand the context in which Psycho-Spiritual Integrative Therapy (PSIT), a group intervention, promotes varying degrees of spiritual growth and quality of life change in breast cancer survivors. A secondary aim was to explore the relationship between spiritual well-being (SWB) and Quality of Life (QL) in PSIT participants. A qualitative, multiple case analysis was undertaken to examine the experiences of two participants with the highest change scores on the Functional Assessment of Chronic Illness Therapy Spiritual Well-Being Scale-Expanded Version (FACIT-Sp-Ex) and two participants with among the lowest change scores on this measure. The participant factors thought to contribute to SWB and QL changes included utilization of metacognitive psychological skills and spiritual/religious frameworks, while PSIT factors included application of PSIT core intervention components, cognitive restructuring, group dynamics, and the role of the facilitator. The nature and extent of participant use of spiritual practices appeared to shape the relationship between SWB and OL. The findings suggest directions for future research to investigate potential moderators and mediators of treatment efficacy of PSIT specifically, as well as other psycho-spiritual interventions for cancer survivors more generally
Molecular Systematics of Pinniped Hookworms (Nematoda: \u3ci\u3eUncinaria\u3c/i\u3e): Species Delimitation, Host Associations and Host-Induced Morphometric Variation
Hookworms of the genus Uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, Uncinaria lucasi from northern fur seals (Callorhinus ursinus) and Uncinaria hamiltoni from South American sea lions (Otaria flavescens). Hookworms were sampled from these hosts and seven additional species including Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), South American fur seals (Arctocephalus australis), Australian fur seals (Arctocephalus pusillus), New Zealand sea lions (Phocarctos hookeri), southern elephant seals (Mirounga leonina), and the Mediterranean monk seal (Monachus monachus). One hundred and thirteen individual hookworms, including an outgroup species, were sequenced for four genes representing two loci (nuclear ribosomal DNA and mitochondrial DNA). Phylogenetic analyses of these sequences recovered seven independent evolutionary lineages or species, including the described species and five undescribed species. The molecular evidence shows that U. lucasi parasitises both C. ursinus and E. jubatus, whereas U. hamiltoni parasitises O. flavescens and A. australis. The five undescribed hookworm species were each associated with single host species (Z. californianus, A. pusillus, P. hookeri, M. leonina and M. monachus). For parasites of otarids, patterns of Uncinaria host-sharing and phylogenetic relationships had a strong biogeographic component with separate clades of parasites from northern versus southern hemisphere hosts. Comparison of phylogenies for these hookworms and their hosts suggests that the association of U. lucasi with northern fur seals results from a host-switch from Steller sea lions. Morphometric data for U. lucasi shows marked host-associated size differences for both sexes, with U. lucasi individuals from E. jubatus significantly larger. This result suggests that adult growth of U. lucasi is reduced within the host species representing the more recent host– parasite association. Intraspecific host-induced size differences are inconsistent with the exclusive use of morphometrics to delimit and diagnose species of Uncinaria from pinnipeds
Genetic basis for in vivo daptomycin resistance in enterococci
Daptomycin is a lipopeptide with bactericidal activity that acts on the cell membrane of enterococci and is often used off-label to treat patients infected with vancomycin-resistant enterococci. However, the emergence of resistance to daptomycin during therapy threatens its usefulness.
We performed whole-genome sequencing and characterization of the cell envelope of a clinical pair of vancomycin-resistant Enterococcus faecalis isolates from the blood of a patient with fatal bacteremia; one isolate (S613) was from blood drawn before treatment and the other isolate (R712) was from blood drawn after treatment with daptomycin. The minimal inhibitory concentrations (MICs) of these two isolates were 1 and 12 μg per milliliter, respectively. Gene replacements were made to exchange the alleles found in isolate S613 with those in isolate R712.
Isolate R712 had in-frame deletions in three genes. Two genes encoded putative enzymes involved in phospholipid metabolism, GdpD (which denotes glycerophosphoryl diester phosphodiesterase) and Cls (which denotes cardiolipin synthetase), and one gene encoded a putative membrane protein, LiaF (which denotes lipid II cycle-interfering antibiotics protein but whose exact function is not known). LiaF is predicted to be a member of a three-component regulatory system (LiaFSR) involved in the stress-sensing response of the cell envelope to antibiotics. Replacement of the liaF allele of isolate S613 with the liaF allele from isolate R712 quadrupled the MIC of daptomycin, whereas replacement of the gdpD allele had no effect on MIC. Replacement of both the liaF and gdpD alleles of isolate S613 with the liaF and gdpD alleles of isolate R712 raised the daptomycin MIC for isolate S613 to 12 μg per milliliter. As compared with isolate S613, isolate R712 — the daptomycin-resistant isolate — had changes in the structure of the cell envelope and alterations in membrane permeability and membrane potential.
Mutations in genes encoding LiaF and a GdpD-family protein were necessary and sufficient for the development of resistance to daptomycin during the treatment of vancomycin-resistant enterococci