618 research outputs found
An improved non-invasive method for measuring heartbeat of intertidal animals
Since its emergence two decades ago, the use of infrared technology for noninvasively measuring the heartbeat
rates of invertebrates has provided valuable insight into the physiology and ecology of intertidal organisms.
During that time period, the hardware needed for this method has been adapted to currently available electronic
components, making the original published description obsolete. This article reviews the history of heartbeat sensing
technology, and describes the design and function of a modern and simplified infrared heartbeat rate sensing
system compatible with many intertidal and marine invertebrates. This technique overcomes drawbacks and
obstacles encountered with previous methods of heartbeat rate measurement, and due to the sensor’s small size,
versatility, and noninvasive nature, it creates new possibilities for studies across a wide range of organismal type
Melanin in Fonsecaea pedrosoi: a trap for oxidative radicals
<p>Abstract</p> <p>Background</p> <p>The pathogenic fungus <it>Fonsecaea pedrosoi </it>constitutively produces the pigment melanin, an important virulence factor in fungi. Melanin is incorporated in the cell wall structure and provides chemical and physical protection for the fungus.</p> <p>We evaluated the production of nitric oxide (NO) in macrophages, the oxidative burst and the inducible nitric oxide synthase (i-NOS) activity in interactions between activated murine macrophages and <it>F. pedrosoi</it>. Experiments were carried out with or without tricyclazole (TC) treatment, a selective inhibitor of the dihydroxynaphthalene (DHN)-melanin biosynthesis pathway in <it>F. pedrosoi</it>. The paramagnetisms of melanin and the TC-melanin were analysed by electron spin resonance. The fungal growth responses to H<sub>2</sub>O<sub>2 </sub>and to S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide donor, were also evaluated.</p> <p>Results</p> <p>Melanised <it>F. pedrosoi </it>cells were more resistant to both H<sub>2</sub>O<sub>2 </sub>and NO. Nitrite was not detected in the supernatant of macrophages incubated with melanised fungal cells. However, i-NOS expression was unaffected by the presence of either untreated control <it>F. pedrosoi </it>or TC-treated <it>F. pedrosoi</it>. In addition, the inhibition of the DHN-melanin pathway by TC improved the oxidative burst capability of the macrophages.</p> <p>Conclusion</p> <p>The NO-trapping ability of <it>F. pedrosoi </it>melanin is an important mechanism to escape the oxidative burst of macrophages.</p
Conditional ablation of the choroideremia gene causes age-related changes in mouse retinal pigment epithelium.
The retinal pigment epithelium (RPE) is a pigmented monolayer of cells lying between the photoreceptors and a layer of fenestrated capillaries, the choriocapillaris. Choroideremia (CHM) is an X-linked progressive degeneration of these three layers caused by the loss of function of Rab Escort protein-1 (REP1). REP1 is involved in the prenylation of Rab proteins, key regulators of membrane trafficking. To study the pathological consequences of chronic disruption of membrane traffic in the RPE we used a cell type-specific knock-out mouse model of the disease, where the Chm/Rep1 gene is deleted only in pigmented cells (Chm(Flox), Tyr-Cre+). Transmission electron microscopy (TEM) was used to quantitate the melanosome distribution in the RPE and immunofluorescent staining of rhodopsin was used to quantitate phagocytosed rod outer segments in retinal sections. The ultrastructure of the RPE and Bruch's membrane at different ages was characterised by TEM to analyse age-related changes occurring as a result of defects in membrane traffic pathways. Chm/Rep1 gene knockout in RPE cells resulted in reduced numbers of melanosomes in the apical processes and delayed phagosome degradation. In addition, the RPE accumulated pathological changes at 5-6 months of age similar to those observed in 2-year old controls. These included the intracellular accumulation of lipofuscin-containing deposits, disorganised basal infoldings and the extracellular accumulation of basal laminar and basal linear deposits. The phenotype of the Chm(Flox), Tyr-Cre+ mice suggests that loss of the Chm/Rep1 gene causes premature accumulation of features of aging in the RPE. Furthermore, the striking similarities between the present observations and some of the phenotypes reported in age-related macular degeneration (AMD) suggest that membrane traffic defects may contribute to the pathogenesis of AMD
Delays in access to care for abortion-related complications: the experience of women in Northeast Brazil.
Around 18 million unsafe abortions occur in low and middle-income countries and are associated with numerous adverse consequences to women's health. The time taken by women with complications to reach facilities where they can receive appropriate post-abortion care can influence the risk of death and the extent of further complications. All women aged 18+ admitted for abortion complications to public-sector hospitals in three capital cities in the Northeastern Brazil between August-December 2010 were interviewed; medical records were extracted (N = 2,804). Nearly all women (94%) went straight to a health facility, mainly to a hospital (76.6%); the rest had various care-seeking paths, with a quarter visiting 3+ hospitals. Women waited 10 hours on average before deciding to seek care. 29% reported difficulties in starting to seek care, including facing challenges in organizing childcare, a companion or transport (17%) and fear/stigma (11%); a few did not initially recognize they needed care (0.4%). The median time taken to arrive at the ultimate facility was 36 hours. Over a quarter of women reported experiencing difficulties being admitted to a hospital, including long waits (15%), only being attended after pregnant women (8.9%) and waiting for a bed (7.4%). Almost all women (90%) arrived in good condition, but those with longer delays were more likely to have (mild or severe) complications. In Brazil, where access to induced abortion is restricted, women face numerous difficulties receiving post-abortion care, which contribute to delay and influence the severity of post-abortion complications
Prenatal ultrasound and postmortem histologic evaluation of tooth germs: an observational, transversal study
Introduction: Hypodontia is the most frequent developmental anomaly of the orofacial complex, and its detection in prenatal ultrasound may indicate the presence of congenital malformations, genetic syndromes and chromosomal abnormalities.To date, only a few studies have evaluated the histological relationship of human tooth germs identified by two-dimensional (2D) ultrasonography. In order to analyze whether two-dimensional ultrasonography of tooth germs may be successfully used for identifying genetic syndromes, prenatal ultrasound images of fetal tooth germs obtained from a Portuguese population sample were compared with histological images obtained from fetal autopsies.Methods: Observational, descriptive, transversal study. The study protocol followed the ethical principles outlined by the Helsinki Declaration and was approved by the Ethics Committee of the School of Dental Medicine, University of Porto (FMDUP, Porto, Portugal) and of the Centro Hospitalar de Vila Nova de Gaia/Espinho (CHVNG/EPE, Porto, Portugal) as well as by the CGC Genetics Embryofetal Pathology Laboratory. Eighty-five fetuses examined by prenatal ultrasound screening from May 2011 to August 2012 had an indication for autopsy following spontaneous fetal death or medical termination of pregnancy. Of the 85 fetuses, 37 (43.5%) were randomly selected for tooth germ evaluation by routine histopathological analysis. Fetuses who were up to 30 weeks of gestation, and whose histological pieces were not representative of all maxillary tooth germs was excluded. Twenty four fetus between the 13th and 30th weeks of gestation fulfilled the parameters to autopsy.Results: Twenty four fetuses were submitted to histological evaluation and were determined the exact number, morphology, and mineralization of their tooth germs. All tooth germs were identifiable with ultrasonography as early as the 13th week of gestation. Of the fetuses autopsied, 41.7% had hypodontia (29.1% maxillary hypodontia and 20.9% mandibular hypodontia).Conclusions: This results indicateinfo:eu-repo/semantics/publishedVersio
Neuroethologic differences in sleep deprivation induced by the single- and multiple-platform methods
Socio-economic inequalities in physical activity practice among Italian children and adolescents: a cross-sectional study
Aim: The aim of the study was to evaluate whether socio-economic inequalities in the practice of physical activity existed among children and adolescents, using different indicators of socio-economic status (SES). Subjects and methods: Data were derived from the Italian National Health Interview Survey carried out in 2004–2005, which examined a large random sample of the Italian population using both an interviewer-administered and a self-compiled questionnaire. This study was based on a sample of 15,216 individuals aged 6–17 years. The practice of physical activity was measured on the basis of questions regarding frequency and intensity of activity during leisure time over the past 12 months. Parents’ educational and occupational level, as well as family’s availability of material resource, were used as indicators of SES. Multivariable logistic regression analyses were performed to estimate the contribution of each SES indicator to the practice of physical activity, adjusting for potential confounding factors. The results of the regression models are expressed as odds ratio (OR) with 95% confidence intervals (95% CI). Results: About 64% of children and adolescents in the sample declared that they participated in moderate or vigorous physical activity at least once a week. After adjustment for gender, age, parental attitudes towards physical activity and geographical area, the practice of physical activity increased with higher parental educational and occupational level and greater availability of material resources. Children and adolescents whose parents held a middle or high educational title were 80% more likely to practice moderate or vigorous physical activity than subjects whose parents had a lower level of education (OR = 1.80, 95% CI: 1.40–2.33), while subjects with unemployed parents had an odds of practicing moderate or vigorous physical activity 0.43 times that of those children whose parents belonged to the top job occupation category (administrative/professionals). Socio-economic differences were about the same when the practice of vigorous physical activity only was considered instead of that of moderate or vigorous physical activity. Conclusion: Interventions that promote the practice of physical activity, and especially those aimed at the wider physical and social environment, are strongly needed to contrast socio-economic differences in physical activity among children and adolescents
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Construction and evaluation of nitric oxide generating vascular graft material loaded with organoselenium catalyst via layer-by-layer self-assembly
Mutational analysis of the β-subunit of yeast geranylgeranyl transferase I
The gene CAL1 (also known as CDC43 ) of Saccharomyces cerevisiae encodes the β subunit of geranylgeranyl transferase I (GGTase I), which modifies several small GTPases. Biochemical analyses of the mutant-enzymes encoded by cal1 , and cdc43-2 to cdc43-7 , expressed in bacteria, have hown that all of the mutant enzymes possess reduced activity, and that none shows temerature-sensitive enzymatic activities. Nonetheless, all of the cal1/cdc43 mutants show temperature-sensitive growth phenotypes. Increase in soluble pools of the small GTPases was observed in the yeast mutant cells at the restrictive temperature in vivo, suggesting that the yeast prenylation pathway itself is temperative sensitive. The cal-1 mutation, located most proximal to the C-terminus of the protein, differs from the other cdc43 mutations in several respects. An increase in soluble Rholp was observed in the cal-1 strain grown at the restrictive temperature. The temperature-sensitive phenotype of cal-1 is most efficiently suppressed by overproduction of Rholp. Overproduction of the other essential target, Cdc42p, in contrast, is deleterious in cal-1 cells, but not in other cdc43 mutants or the wild-type strains. The cdc43-5 mutant cells accumulate Cdc42p in soluble pools and cdc43-5 is suppressed by overproduction of Cdc42p. Thus, several phenotypic differences are observed among the cal1/cdc43 mutations, possibly due to alterations in substrate specificity caused by the mutations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42258/1/438-252-1-2-1_62520001.pd
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