1,137 research outputs found
Pearse Hutchinson New Collections at Special Collections & Archives Maynooth University Library
In late 2013 agreement was reached with the estate of the renowned writer Pearse Hutchinson to permanently deposit his archive in the Library at Maynooth Universi-ty. While this will lead to a variety of provisions, such as an annual bursary and colloquia, at the centre of the whole project is the archival collection, in breadth and content, every bit as extraordinary as the man
First-principles calculation of P-type alloy scattering in Si1-xGex
The p-type carrier scattering rate due to alloy disorder in Si1-xGex alloys is obtained from first principles. The required alloy scattering matrix elements are calculated from the energy splitting of the valence bands, which arise when one average host atom is replaced by a Ge or Si atom in supercells containing up to 128 atoms. Alloy scattering within the valence bands is found to be characterized by a single scattering parameter. The hole mobility is calculated from the scattering rate using the Boltzmann transport equation in the relaxation time approximation. The results are in good agreement with experiments on bulk, unstrained alloys.
Outcome of pregnancy in the era of highly active antiretroviral: a 10-year experience in Southern Ireland
Introduction: Since the introduction of HAART the desire to become a mother in women with HIV has become a viable option due to the drastic reduction in vertical transmission. The aim of this study was to look at the epidemiology, clinical characteristics, and safety of antiretroviral drugs and rate of vertical transmission in our cohort in the Munster region, Ireland. Methods: We retrospectively reviewed all pregnant women with HIV who attended the ID clinic from January 2002 to April 2012. Patients’ demographics, pertinent laboratory data, and pharmacy records were reviewed and statistically analysed. Results: 105 HIV-positive women, with a total of 165 pregnancies, were seen from January 2002 to April 2012 at Cork University Hospital: 46 patients were previously known to be HIV-infected at their first pregnancy and 59 were diagnosed during antenatal screening (median of 32 week gestation at diagnosis). The median age at the time of pregnancy was 32 and the HIV transmission was 90% sexual: 39 women were from Europe/Asia and 66 were African; only two women were HCV co-infected and one was HBV co-infected. Of the patients diagnosed with HIV prior to pregnancy, 13 were on treatment, all of whom had no detectable virus at the start and during pregnancy. The median CD4+ at the start of pregnancy was 490 cells/µl. The median weeks of gestation at the start of HAART was 28 before 2006 and 20 after 2006, in accordance with National Guidelines. The HAART regime used was in line with current Guidelines. 18 pregnancies ended in miscarriage before week 12 gestation and 2 pregnancies resulted in intrauterine death at 28 weeks. 145 pregnancies progressed to delivery at full term but 10 infants were born before the 37th week, with one baby born at 23 weeks: 63 had SVD and 82 underwent C-section, of whom 12 emergency C-section due to prolonged membrane rupture. Most of the C-sections were planned due to obstetric reasons. 2 infants were born HIV+: in one case the mother was a late presenter at 38 of gestation; and in other the mother had poor compliance with viral load detectable at the time of labour. The overall number of pregnancies per year has been stable over the ten years (average of 14 pregnancies per year). Conclusion: The use of cART with high level of adherence and a close clinical management during pregnancy has shown to dramatically reduce the vertical transmission of HIV in our cohort
La exigibilidad de los Convenios de Accionistas frente a la sociedad y el principio de relatividad contractual
The following article will address the topic of why should the Peruvian General Corporations Law be modified, in order to specify in which cases a shareholders agreement can impose obligations on the company and in which cases it can only be opposable. Moreover, the author will proposes that the application of said law should be done through a systematic interpretation with the Civil Code.DOI: 10.26439/advocatus2018.n036.4738El siguiente artículo expondrá motivos sobre por qué la Ley General de Sociedades requiere ser mejorada, a fin de precisar en qué supuestos un convenio de accionistas puede imponerle obligaciones a la sociedad y en qué casos puede serle únicamente oponible. Asimismo, propone que la aplicación de dicha norma debe darse a través de una interpretación sistemática con el Código Civil
A Reduction in Serum Cytokine Levels Parallels Healing of Venous Ulcers in Patients Undergoing Compression Therapy
AbstractIntroduction vascular endothelial growth factor (VEGF) and tumour necrosis factor alpha (TNFα) have been specifically implicated in the tissue damage associated with chronic venous disease (CVD). Furthermore, production of both factors is known to be upregulated in vessel wall cells subject to hypertension. The aim of this study was to determine the local venous levels of VEGF and TNFα in limbs with venous ulcers before and after treatment with graduated compression. Patients and methods eight patients with venous ulcers and 8 patients with varicose veins only were included in the study. For ulcer patients, serum samples were taken from the superficial veins in lower limbs and repeated after 4 weeks of treatment with 4-layered graduated compression. Serum from the arms of the same patients served as controls. Determination of the concentrations of VEGF and TNFα proteins were performed with sandwich enzyme-linked immunosorbent assays. Results both groups of patients had elevated levels of VEGF and TNFα. In patients with venous ulcers there was a reduction in the levels of both cytokines to below control values with treatment. These changes correlated with healing of the ulcers as determined by reduction in ulcer size. Conclusion these data, for the first time, suggest a central role for both TNFα and VEGF in the pathogenesis of venous ulceration which may constitute a causative link between venous hypertension and tissue pathology
A precise asteroseismic age and metallicity for HD139614: a pre-main-sequence star with a protoplanetary disc in Upper Centaurus-Lupus
HD 139614 is known to be a ∼14-Myr-old, possibly pre-main-sequence star in the Sco-Cen OB association in the Upper Centaurus-Lupus subgroup, with a slightly warped circumstellar disc containing ring structures hinting at one or more planets. The star’s chemical abundance pattern is metal-deficient except for volatile elements, which places it in the λ Boo class and suggests it has recently accreted gas-rich but dust-poor material. We identify seven dipole and four radial pulsation modes among its δ Sct pulsations using the TESS light curve and an échelle diagram. Precision modelling with the MESA stellar evolution and GYRE stellar oscillation programs confirms it is on the pre-main sequence. Asteroseismic, grid-based modelling suggests an age of 10.75 ± 0.77 Myr, a mass of 1.52 ± 0.02 M ⊙, and a global metal abundance of Z = 0.0100 ± 0.0010. This represents the first asteroseismic determination of the bulk metallicity of a λ Boo star. The precise age and metallicity offer a benchmark for age estimates in Upper Centaurus–Lupus, and for understanding disc retention and planet formation around intermediate-mass stars
A grid of 800,000 models of delta Scuti stars using MESA and GYRE
The rapidly increasing number of delta Scuti stars with regular patterns
among their pulsation frequencies necessitates modelling tools to better
understand the observations. Further, with a dozen identified modes per star,
there is potential to make meaningful inferences on stellar structure using
these young Sct stars. We compute and describe a grid of 800,000
stellar models from the early pre-main-sequence to roughly one third of the
main-sequence lifetime, and calculate their pulsation frequencies. From these,
we also calculate asteroseismic parameters and explore how those parameters
change with mass, age, and metal mass fraction. We show that the large
frequency separation, , is insensitive to mass at the zero-age main
sequence. In the frequency regime observed, the we measure (from
modes with --9) differs from the solar scaling relation by 13%.
We find that the lowest radial order is often poorly modelled, perhaps
indicating that the lower-order pressure modes contain further untapped
potential for constraining the stellar structure. We also show that different
nuclear reaction networks available in MESA can affect the pulsation
frequencies of young Sct stars by as much as 5%. We apply the grid to
five newly modelled stars, including two pre-main-sequence stars each with 15+
modes identified, and we make the grid available as a community resource.Comment: 17 pages including appendices. Submitted to MNRA
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Suppression of reactive oxygen species generation in heart mitochondria from anoxic turtles: the role of complex I S-nitrosation.
Freshwater turtles (Trachemys scripta) are among the very few vertebrates capable of tolerating severe hypoxia and re-oxygenation without suffering from damage to the heart. As myocardial ischemia and reperfusion causes a burst of mitochondrial reactive oxygen species (ROS) in mammals, the question arises as to whether, and if so how, this ROS burst is prevented in the turtle heart. We find that heart mitochondria isolated from turtles acclimated to anoxia produce less ROS than mitochondria from normoxic turtles when consuming succinate. As succinate accumulates in the hypoxic heart and is oxidized when oxygen returns, this suggests an adaptation to lessen ROS production. Specific S-nitrosation of complex I can lower ROS in mammals and here we show that turtle complex I activity and ROS production can also be strongly depressed in vitro by S-nitrosation. We detect in vivo endogenous S-nitrosated complex I in turtle heart mitochondria, but these levels are unaffected upon anoxia acclimation. Thus, while heart mitochondria from anoxia-acclimated turtles generate less ROS and have a lower aerobic capacity than those from normoxic turtles, this is not due to decreases in complex I activity or expression levels. Interestingly, in-gel activity staining reveals that most complex I of heart mitochondria from normoxic and anoxic turtles forms stable super-complexes with other respiratory enzymes and, in contrast to mammals, these are not disrupted by dodecyl maltoside. Taken together, these results show that although S-nitrosation of complex I is a potent mechanism to prevent ROS formation upon re-oxygenation after anoxia in vitro, this is not a major cause of the suppression of ROS production by anoxic turtle heart mitochondria
Myeloid DAP12-associating lectin (MDL)-1 regulates synovial inflammation and bone erosion associated with autoimmune arthritis.
DNAX adaptor protein 12 (DAP12) is a trans-membrane adaptor molecule that transduces activating signals in NK and myeloid cells. Absence of functional Dap12 results in osteoclast defects and bone abnormalities. Because DAP12 has no extracelluar binding domains, it must pair with cell surface receptors for signal transduction. There are at least 15 known DAP12-associating cell surface receptors with distinct temporal and cell type-specific expression patterns. Our aim was to determine which receptors may be important in DAP12-associated bone pathologies. Here, we identify myeloid DAP12-associating lectin (MDL)-1 receptor (also known as CLEC5A) as a key regulator of synovial injury and bone erosion during autoimmune joint inflammation. Activation of MDL-1 leads to enhanced recruitment of inflammatory macrophages and neutrophils to the joint and promotes bone erosion. Functional blockade of MDL-1 receptor via Mdl1 deletion or treatment with MDL-1-Ig fusion protein reduces the clinical signs of autoimmune joint inflammation. These findings suggest that MDL-1 receptor may be a therapeutic target for treatment of immune-mediated skeletal disorders
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