1,357 research outputs found
Spirometry reference equations for central European populations from school age to old age.
Spirometry reference values are important for the interpretation of spirometry results. Reference values should be updated regularly, derived from a population as similar to the population for which they are to be used and span across all ages. Such spirometry reference equations are currently lacking for central European populations. To develop spirometry reference equations for central European populations between 8 and 90 years of age. We used data collected between January 1993 and December 2010 from a central European population. The data was modelled using "Generalized Additive Models for Location, Scale and Shape" (GAMLSS). The spirometry reference equations were derived from 118'891 individuals consisting of 60'624 (51%) females and 58'267 (49%) males. Altogether, there were 18'211 (15.3%) children under the age of 18 years. We developed spirometry reference equations for a central European population between 8 and 90 years of age that can be implemented in a wide range of clinical settings
Una aplicaci?n de la teor?a del comportamiento planificado al segmento masculino latinoamericano de productos de cuidado personal
This research study identifies those factors which influence the consumption of care products in the Latinamerican male segment. That's why, an instrument based on the behavorial theory was applied to 600 men living in two countries of this regi?n and having different levels of development regarding the above mentioned category, Mexico -highly developed- and Peru -moderately developed-. The data obtained were analyzed using a model of structural equations. The results show that a subjective norm will stop men's consumption of these kinds of products. Similarly, the impact of this subjective norm will be lower in young men, allowing them to have a great aperture in the consumption of these care products.Este estudio busca identificar los factores que influyen en el consumo de productos de cuidado personal dentro del segmento masculino latinoamericano. Para ello, se aplic? un instrumento basado en la teor?a del comportamiento planificado a 600 hombres pertenecientes a dos pa?ses de la regi?n con diferentes niveles de desarrollo de la categor?a en cuesti?n: M?xico (alto desarrollo) y Per? (moderado desarrollo). Los datos obtenidos fueron analizados a partir de un modelo de ecuaciones estructurales. Los resultados sugieren que, en ambos pa?ses estudiados, la norma subjetiva inhibir?a el consumo de este tipo de productos entre los hombres. Asimismo, el impacto de la norma subjetiva ser?a menor en hombres j?venes, teniendo ellos mayor apertura al consumo de estos productos
The native architecture of a photosynthetic membrane
In photosynthesis, the harvesting of solar energy and its subsequent conversion into a stable charge separation are dependent upon an interconnected macromolecular network of membrane-associated chlorophyll–protein complexes. Although the detailed structure of each complex has been determined, the size and organization of this network are unknown. Here we show the use of atomic force microscopy to directly reveal a native bacterial photosynthetic membrane. This first view of any multi-component membrane shows the relative positions and associations of the photosynthetic complexes and reveals crucial new features of the organization of the network: we found that the membrane is divided into specialized domains each with a different network organization and in which one type of complex predominates. Two types of organization were found for the peripheral light-harvesting LH2 complex. In the first, groups of 10–20 molecules of LH2 form light-capture domains that interconnect linear arrays of dimers of core reaction centre (RC)–light-harvesting 1 (RC–LH1–PufX) complexes; in the second they were found outside these arrays in larger clusters. The LH1 complex is ideally positioned to function as an energy collection hub, temporarily storing it before transfer to the RC where photochemistry occurs: the elegant economy of the photosynthetic membrane is demonstrated by the close packing of these linear arrays, which are often only separated by narrow 'energy conduits' of LH2 just two or three complexes wide
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TRIM32 Regulates Skeletal Muscle Stem Cell Differentiation and Is Necessary for Normal Adult Muscle Regeneration
Limb girdle muscular dystrophy type 2H (LGMD2H) is an inherited autosomal recessive disease of skeletal muscle caused by a mutation in the TRIM32 gene. Currently its pathogenesis is entirely unclear. Typically the regeneration process of adult skeletal muscle during growth or following injury is controlled by a tissue specific stem cell population termed satellite cells. Given that TRIM32 regulates the fate of mammalian neural progenitor cells through controlling their differentiation, we asked whether TRIM32 could also be essential for the regulation of myogenic stem cells. Here we demonstrate for the first time that TRIM32 is expressed in the skeletal muscle stem cell lineage of adult mice, and that in the absence of TRIM32, myogenic differentiation is disrupted. Moreover, we show that the ubiquitin ligase TRIM32 controls this process through the regulation of c-Myc, a similar mechanism to that previously observed in neural progenitors. Importantly we show that loss of TRIM32 function induces a LGMD2H-like phenotype and strongly affects muscle regeneration in vivo. Our studies implicate that the loss of TRIM32 results in dysfunctional muscle stem cells which could contribute to the development of LGMD2H
The Antibacterial Activity of Honey Derived from Australian Flora
Chronic wound infections and antibiotic resistance are driving interest in
antimicrobial treatments that have generally been considered complementary,
including antimicrobially active honey. Australia has unique native flora and
produces honey with a wide range of different physicochemical properties. In
this study we surveyed 477 honey samples, derived from native and exotic plants
from various regions of Australia, for their antibacterial activity using an
established screening protocol. A level of activity considered potentially
therapeutically useful was found in 274 (57%) of the honey samples, with
exceptional activity seen in samples derived from marri (Corymbia
calophylla), jarrah (Eucalyptus marginata) and
jellybush (Leptospermum polygalifolium). In most cases the
antibacterial activity was attributable to hydrogen peroxide produced by the
bee-derived enzyme glucose oxidase. Non-hydrogen peroxide activity was detected
in 80 (16.8%) samples, and was most consistently seen in honey produced
from Leptospermum spp. Testing over time found the hydrogen
peroxide-dependent activity in honey decreased, in some cases by 100%,
and this activity was more stable at 4°C than at 25°C. In contrast, the
non-hydrogen peroxide activity of Leptospermum honey samples
increased, and this was greatest in samples stored at 25°C. The stability of
non-peroxide activity from other honeys was more variable, suggesting this
activity may have a different cause. We conclude that many Australian honeys
have clinical potential, and that further studies into the composition and
stability of their active constituents are warranted
Distributions of epistasis in microbes fit predictions from a fitness landscape model.
How do the fitness effects of several mutations combine? Despite its simplicity, this question is central to the understanding of multilocus evolution. Epistasis (the interaction between alleles at different loci), especially epistasis for fitness traits such as reproduction and survival, influences evolutionary predictions "almost whenever multilocus genetics matters". Yet very few models have sought to predict epistasis, and none has been empirically tested. Here we show that the distribution of epistasis can be predicted from the distribution of single mutation effects, based on a simple fitness landscape model. We show that this prediction closely matches the empirical measures of epistasis that have been obtained for Escherichia coli and the RNA virus vesicular stomatitis virus. Our results suggest that a simple fitness landscape model may be sufficient to quantitatively capture the complex nature of gene interactions. This model may offer a simple and widely applicable alternative to complex metabolic network models, in particular for making evolutionary predictions
Robust penetrating microelectrodes for neural interfaces realized by titanium micromachining
Neural prosthetic interfaces based upon penetrating microelectrode devices have broadened our understanding of the brain and have shown promise for restoring neurological functions lost to disease, stroke, or injury. However, the eventual viability of such devices for use in the treatment of neurological dysfunction may be ultimately constrained by the intrinsic brittleness of silicon, the material most commonly used for manufacture of penetrating microelectrodes. This brittleness creates predisposition for catastrophic fracture, which may adversely affect the reliability and safety of such devices, due to potential for fragmentation within the brain. Herein, we report the development of titanium-based penetrating microelectrodes that seek to address this potential future limitation. Titanium provides advantage relative to silicon due to its superior fracture toughness, which affords potential for creation of robust devices that are resistant to catastrophic failure. Realization of these devices is enabled by recently developed techniques which provide opportunity for fabrication of high-aspect-ratio micromechanical structures in bulk titanium substrates. Details are presented regarding the design, fabrication, mechanical testing, in vitro functional characterization, and preliminary in vivo testing of devices intended for acute recording in rat auditory cortex and thalamus, both independently and simultaneously
Differential Dynamics of Transposable Elements during Long-Term Diploidization of Nicotiana Section Repandae (Solanaceae) Allopolyploid Genomes
PubMed ID: 23185607This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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