125 research outputs found
Solvent Tuning of Electrochemical Potentials in the Active Sites of HiPIP Versus Ferredoxin
No full textA persistent puzzle in the field of biological electron transfer is the conserved iron-sulfur cluster motif in both high potential iron-sulfur protein (HiPIP) and ferredoxin (Fd) active sites. Despite this structural similarity, HiPIPs react oxidatively at physiological potentials, whereas Fds are reduced. Sulfur K-edge x-ray absorption spectroscopy uncovers the substantial influence of hydration on this variation in reactivity. Fe-S covalency is much lower in natively hydrated Fd active sites than in HiPIPs but increases upon water removal; similarly, HiPIP covalency decreases when unfolding exposes an otherwise hydrophobically shielded active site to water. Studies on model compounds and accompanying density functional theory calculations support a correlation of Fe-S covalency with ease of oxidation and therefore suggest that hydration accounts for most of the difference between Fd and HiPIP reduction potentials
The influence of tropical Pacific weather on U.S. heat waves
No full textLong-range predictions of heat waves offer little improvement over climatology despite the continuing improvements of weather forecast models. Tropical variability in weather at sub-seasonal timescales is well-understood to influence weather in the Extratropics, particularly in the winter. For this reason, it is considered a potential source of sub-seasonal predictability of weather. However, much less is understood about the tropical-extratropical connection in the summer. we show that a major climate oscillation in the tropical west pacific is significantly correlated to U.S. heat waves with long lead times, suggesting potential for use in seasonal prediction of these events.Great Minds in Research - Honorable Mention
Klebsiella Vaccines and Immunotherapeutics
No full text$AUD 98,345.69NHMRC Postgraduate ScholarshipsMedical Postgraduate Scholarshi
Observation of Terhertz Vibrations in Pyrococcus furiosus Rubredoxin via Impulsive Coherent Vibrational Spectroscopy and Nuclear Resonance Vibrational Spectroscopy - Interpretation by Molecular Mechanics
No full textWe have used impulsive coherent vibrational spectroscopy (ICVS) to study the Fe(S-Cys)4 site in oxidized rubredoxin (Rd) from Pyrococcus furiosus (Pf). In this experiment, a 15 fs visible laser pulse is used to coherently pump the sample to an excited electronic state, and a second \u3c10 fs pulse is used to probe the change in transmission as a function of the time delay. PfRd was observed to relax to the ground state by a single exponential decay with time constants of ∼255-275 fs. Superimposed on this relaxation are oscillations caused by coherent excitation of vibrational modes in both excited and ground electronic states. Fourier transformation reveals the frequencies of these modes. The strongest ICV mode with 570 nm excitation is the symmetric Fe-S stretching mode near 310 cm-1, compared to 313 cm-1 in the low temperature resonance Raman. If the rubredoxin is pumped at 520 nm, a set of strong bands occurs between 20 and 110 cm-1. Finally, there is a mode at ∼500 cm-1 which is similar to features near 508 cm-1 in blue Cu proteins that have been attributed to excited state vibrations. Normal mode analysis using 488 protein atoms and 558 waters gave calculated spectra that are in good agreement with previous nuclear resonance vibrational spectra (NRVS) results. The lowest frequency normal modes are identified as collective motions of the entire protein or large segments of polypeptide. Motion in these modes may affect the polar environment of the redox site and thus tune the electron transfer functions in rubredoxins. © 2006 Elsevier Inc. All rights reserved
The harvest of the earth: The Feast of Sukkoth in the Book of Revelation.
No full textThe Israelite Feast of Sukkoth (alternately Sukkot, Succoth or Succot), also called the Feast of Tabernacles and the Feast of Booths, is the liturgical setting of Revelation. The author traces the development of Sukkoth through 135 CE, categorizing the literature as descriptive, prescriptive or predictive. The appearance of any one of several features can help to identify the pertinent passages: (1) one of the names of the feast, (2) one of the liturgical passages for the feast (e.g. the enthronement psalms), or (3) an otherwise unlikely combination of themes or practices from the feast. The first section concludes by reconstructing the celebration and interpretation of Sukkoth in the first century CE. The themes of the feast had long included harvest, light, water, creation, the exodus, fertility, marriage, rest and the presence of God, the Shekinah. Sukkoth is also the origin of the Day of the Lord, the source of Israel's eschatology. The popular interpretation of the feast in the first-century CE was heavily eschatological, as evidenced by the events surrounding Jesus' triumphal entry. This was due in part to the rebuilt Temple, the unstable times and the Roman promulgation of their own eschatology through the imperial cult. Sukkoth, with its historic link to Jewish independence, the enthronement of the Israelite king, and the Davidic messiah, was an obvious choice for Israel's counter-propaganda. Sukkoth is also the Sitz im Leben of Revelation, as evidenced by the appearance of its name, vocabulary, themes, liturgy and practices in the book. The author hypothesizes that Jesus deliberately used the messianic themes of Sukkoth, but his unexpected death forced his followers to use Passover as a motif for his ministry instead. They deferred their Sukkoth expectations to an anticipated second coming. Revelation uses Sukkoth as a motif because it portrays this second coming. The book challenges the Christians of Asia Minor to reinterpret their situation: the Romans are harvesting them, their blood is the wine of the festival libations and a heavenly celebration of Sukkoth is the soon-to-come end of this grim harvest.PhDAncient historyBiblical studiesCultural anthropologyPhilosophy, Religion and TheologyReligious historySocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/129068/2/9319553.pd
Emerg Infect Dis
No full textWe undertook a prospective active surveillance study of invasive group A streptococcal (GAS) disease in Fiji over a 23-month period, 2005-2007. We identified 64 cases of invasive GAS disease, which represents an average annualized all-ages incidence of 9.9 cases/100,000 population per year (95% confidence interval [CI] 7.6-12.6). Rates were highest in those >65 years of age and in those <5 years, particularly in infants, for whom the incidence was 44.9/100,000 (95% CI 18.1-92.5). The case-fatality rate was 32% and was associated with increasing age and underlying coexisting disease, including diabetes and renal disease. Fifty-five of the GAS isolates underwent emm sequence typing; the types were highly diverse, with 38 different emm subtypes and no particular dominant type. Our data support the view that invasive GAS disease is common in developing countries and deserves increased public health attention
High burden of impetigo and scabies in a tropical country.
No full textBACKGROUND: Impetigo and scabies are endemic diseases in many tropical countries; however the epidemiology of these diseases is poorly understood in many areas, particularly in the Pacific. METHODOLOGY/PRINCIPAL FINDINGS: We conducted three epidemiological studies in 2006 and 2007 to determine the burden of disease due to impetigo and scabies in children in Fiji using simple and easily reproducible methodology. Two studies were performed in primary school children (one study was a cross-sectional study and the other a prospective cohort study over ten months) and one study was performed in infants (cross-sectional). The prevalence of active impetigo was 25.6% (95% CI 24.1-27.1) in primary school children and 12.2% (95% CI 9.3-15.6) in infants. The prevalence of scabies was 18.5% (95% CI 17.2-19.8) in primary school children and 14.0% (95% CI 10.8-17.2) in infants. The incidence density of active impetigo, group A streptococcal (GAS) impetigo, Staphylococcus aureus impetigo and scabies was 122, 80, 64 and 51 cases per 100 child-years respectively. Impetigo was strongly associated with scabies infestation (odds ratio, OR, 2.4, 95% CI 1.6-3.7) and was more common in Indigenous Fijian children when compared with children of other ethnicities (OR 3.6, 95% CI 2.7-4.7). The majority of cases of active impetigo in the children in our study were caused by GAS. S. aureus was also a common cause (57.4% in school aged children and 69% in infants). CONCLUSIONS/SIGNIFICANCE: These data suggest that the impetigo and scabies disease burden in children in Fiji has been underestimated, and possibly other tropical developing countries in the Pacific. These diseases are more than benign nuisance diseases and consideration needs to be given to expanded public health initiatives to improve their control
Bactabolize is a tool for high-throughput generation of bacterial strain-specific metabolic models
No full textMetabolic capacity can vary substantially within a bacterial species, leading to ecological niche separation, as well as differences in virulence and antimicrobial susceptibility. Genome-scale metabolic models are useful tools for studying the metabolic potential of individuals, and with the rapid expansion of genomic sequencing there is a wealth of data that can be leveraged for comparative analysis. However, there exist few tools to construct strain-specific metabolic models at scale. Here, we describe Bactabolize, a reference-based tool which rapidly produces strain-specific metabolic models and growth phenotype predictions. We describe a pan reference model for the priority antimicrobial-resistant pathogen, Klebsiella pneumoniae, and a quality control framework for using draft genome assemblies as input for Bactabolize. The Bactabolize-derived model for K. pneumoniae reference strain KPPR1 performed comparatively or better than currently available automated approaches CarveMe and gapseq across 507 substrate and 2317 knockout mutant growth predictions. Novel draft genomes passing our systematically defined quality control criteria resulted in models with a high degree of completeness (≥99% genes and reactions captured compared to models derived from matched complete genomes) and high accuracy (mean 0.97, n=10). We anticipate the tools and framework described herein will facilitate large-scale metabolic modelling analyses that broaden our understanding of diversity within bacterial species and inform novel control strategies for priority pathogens.Full Tex
DeraciNation: Reading the Borderlands in the Fiction of Zoë Wicomb
No full textThis dissertation analyzes the fiction of South African author Zoë Wicomb (1948- ) through her two collections of short stories: You Can’t Get Lost in Cape Town (1987) and The One that Got Away (2008) and two novels: David’s Story (2000) and Playing in the Light (2006). Using an interdisciplinary approach, the concept of deraciNation, which is the uprooting and discrimination of peoples as a way to uphold the notion of Nation, and an adaptation of Gloria Anzaldúa’s borderland theory in an investigation of the coloured community in its construction as an intermediary group between black and white and its locations in the margins of society, this dissertation investigates how discrimination has not only played a role in the construction and representation of coloured identities, but also how it was adopted and incorporated within the community. Wicomb calls attention to oppression in both external and internal forms, exemplifying the failures of the struggle against apartheid and the self-contradictions that can also be violent. Specifically, this dissertation analyzes the spaces of home, neighborhood and nation, which were locations of deracination through external forces of imperialism and colonialism. Moreover, it examines oppression, which has led to these spaces being gendered and racialized, has persisted in coloured identities in post-apartheid South Africa and transnationally into Europe, two areas in which Wicomb’s fictional writings take place as sites of both home and displacement. Furthermore, this dissertation scrutinizes the notion of truth, through an examination of violence, memory and his/herstories as a way of bringing lesser-known stories to the light.Utilizando un enfoque interdisciplinario, esta tesis analiza la ficción de Zoe Wicomb, autora sudafricana (1948- ), a través de dos colecciones de relatos: You Can’t Get Lost in Cape Town (1987) y The One that Got Away (2008) y dos novelas: David’s Story (2000) y Playing in the Light. En la tesis hemos utilizado el concepto de deraciNation, o desarraigo y discriminación de los pueblos para apoyar la noción de Nación, y una adaptación de la teoría del borderland de Gloria Anzaldúa para la investigación de la comunidad coloured (mestiza) en su construcción como un grupo intermediario entre los blancos y los negros. Esta tesis examina cómo la discriminación ayudó la construcción y representación de las identidades coloured, pero también de que forma se empleaba dicha discriminación dentro la misma comunidad. Wicomb llama nuestra atención hacia la opresión tanto fuera como dentro de la comunidad, demostrando así los fracasos en la lucha contra el apartheid. Además, esta investigación analiza los espacios de hogar, barrio y nación, lugares de desarraigo como producto del imperialismo y del colonialismo. Y finalmente, en este trabajo se examina la opresión, que aun perdura en las identidades "coloured" en Suráfrica tras el apartheid y que ha llegado hasta Europa
Prospective surveillance of invasive group a streptococcal disease, Fiji, 2005-2007.
No full textWe undertook a prospective active surveillance study of invasive group A streptococcal (GAS) disease in Fiji over a 23-month period, 2005-2007. We identified 64 cases of invasive GAS disease, which represents an average annualized all-ages incidence of 9.9 cases/100,000 population per year (95% confidence interval [CI] 7.6-12.6). Rates were highest in those >65 years of age and in those <5 years, particularly in infants, for whom the incidence was 44.9/100,000 (95% CI 18.1-92.5). The case-fatality rate was 32% and was associated with increasing age and underlying coexisting disease, including diabetes and renal disease. Fifty-five of the GAS isolates underwent emm sequence typing; the types were highly diverse, with 38 different emm subtypes and no particular dominant type. Our data support the view that invasive GAS disease is common in developing countries and deserves increased public health attention
- …
