16 research outputs found
Wind-Driven Roof Turbines: A Novel Way to Improve Ventilation for TB Infection Control in Health Facilities
Tuberculosis transmission in healthcare facilities contributes significantly to the TB epidemic, particularly in high HIV settings. Although improving ventilation may reduce transmission, there is a lack of evidence to support low-cost practical interventions. We assessed the efficacy of wind-driven roof turbines to achieve recommended ventilation rates, compared to current recommended practices for natural ventilation (opening windows), in primary care clinic rooms in Khayelitsha, South Africa
The Complete Genome Sequence of Fibrobacter succinogenes S85 Reveals a Cellulolytic and Metabolic Specialist
Fibrobacter succinogenes is an important member of the rumen
microbial community that converts plant biomass into nutrients usable by its
host. This bacterium, which is also one of only two cultivated species in its
phylum, is an efficient and prolific degrader of cellulose. Specifically, it has
a particularly high activity against crystalline cellulose that requires close
physical contact with this substrate. However, unlike other known cellulolytic
microbes, it does not degrade cellulose using a cellulosome or by producing high
extracellular titers of cellulase enzymes. To better understand the biology of
F. succinogenes, we sequenced the genome of the type strain
S85 to completion. A total of 3,085 open reading frames were predicted from its
3.84 Mbp genome. Analysis of sequences predicted to encode for
carbohydrate-degrading enzymes revealed an unusually high number of genes that
were classified into 49 different families of glycoside hydrolases, carbohydrate
binding modules (CBMs), carbohydrate esterases, and polysaccharide lyases. Of
the 31 identified cellulases, none contain CBMs in families 1, 2, and 3,
typically associated with crystalline cellulose degradation. Polysaccharide
hydrolysis and utilization assays showed that F. succinogenes
was able to hydrolyze a number of polysaccharides, but could only utilize the
hydrolytic products of cellulose. This suggests that F.
succinogenes uses its array of hemicellulose-degrading enzymes to
remove hemicelluloses to gain access to cellulose. This is reflected in its
genome, as F. succinogenes lacks many of the genes necessary to
transport and metabolize the hydrolytic products of non-cellulose
polysaccharides. The F. succinogenes genome reveals a bacterium
that specializes in cellulose as its sole energy source, and provides insight
into a novel strategy for cellulose degradation
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar, and APOGEE-2 Data
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys