37 resultados para Menú 2.0
em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast
Resumo:
We report on Australia Telescope Compact Array observations of the massive star-forming region G305.2+0.2 at 1.2 cm. We detected emission in five molecules towards G305A, confirming its hot core nature. We determined a rotational temperature of 26 K for methanol. A non-local thermodynamic equilibrium excitation calculation suggests a kinematic temperature of the order of 200 K. A time-dependent chemical model is also used to model the gas-phase chemistry of the hot core associated with G305A. A comparison with the observations suggest an age of between 2 × 104 and 1.5 × 105 yr. We also report on a feature to the south-east of G305A which may show weak Class I methanol maser emission in the line at 24.933 GHz. The more evolved source G305B does not show emission in any of the line tracers, but strong Class I methanol maser emission at 24.933 GHz is found 3 arcsec to the east. Radio continuum emission at 18.496 GHz is detected towards two H ii regions. The implications of the non-detection of radio continuum emission towards G305A and G305B are also discussed.
Resumo:
We present results from a time-dependent gas-phase chemical model of a hot core based on the physical conditions of G305.2+0.2. While the cyanopolyyne HC3N has been observed in hot cores, the longer chained species, HC5N, HC7N and HC9N, have not been considered as the typical hot-core species. We present results which show that these species can be formed under hot core conditions. We discuss the important chemical reactions in this process and, in particular, show that their abundances are linked to the parent species acetylene which is evaporated from icy grain mantles. The cyanopolyynes show promise as ‘chemical clocks’ which may aid future observations in determining the age of hot core sources. The abundance of the larger cyanopolyynes increases and decreases over relatively short time-scales, ~10^2.5 yr. We present results from a non-local thermodynamic equilibrium statistical equilibrium excitation model as a series of density, temperature and column density dependent contour plots which show both the line intensities and several line ratios. These aid in the interpretation of spectral-line data, even when there is limited line information available. In particular, non-detections of HC5N and HC7N in Walsh et al. are analysed and discussed.
Resumo:
New elements associated withWeb 2.0 relating to interactivity and end-user focus have combined with the availability of newlevels of information to encourage the development of what may be termed a Gov 2.0 approach.This, in combination with recent initiatives in the modernising government programme, has emphasised new levels of public participation and engagement with government as well as a re-engineering of public services tomake them more responsive to their end users. Adopting a governmentality perspective, it is argued that this involves a wider process of governing through constructing and reconstructing ideas of the public, community and individual citizen-consumers who take on a role in their own governance. It is argued that this fundamental re-working of the nature of what is public represents a constitutional change that is perhaps more signi¢cant than the constitutional reform programme directed to formal government which attracts more attention
Resumo:
For The Map of Watchful Architecture I only concerned myself with defensive architecture along the Border. As the map followed a border it came out as a wavy line of points. This was largely artificial, I only charted architecture within the Border corridor, but was not entirely artificial. That linear landscape has long been staked-out by the regularity of certain kinds of architecture. The 1st/2nd century Black Pig’s Dyke and Dorsey correspond with today’s Border. The concentration of souterrains in north Louth indicate that it may have been a volatile interface zone in later centuries. In 1618 Londonderry and its walls were built. Further north and two centuries later, Martello Towers were constructed to watch over Lough Foyle. During the Second World War pillboxes and observation posts were manned along the Border, close to what was now an international frontier. Then came the Operation Banner installations built during The Troubles. All this adds up to be one of the longest unbroken traditions of defensive architecture anywhere in Western Europe, a tradition some thought finally broken as the last of the Operation Banner towers were de-installed in 2007. But, take a bus south across the Border and you will often be pulled over by the Garda Síochána. They ID check the passengers in an attempt to stop illegal immigration via the UK. What about illegal immigrants who walk through the fields or along quiet lanes? They will have understood the Border is not really how it seems on most maps. It is not a solid line, it is a row of points.
Resumo:
In this paper we identify requirements for choosing a threat modelling formalisation for modelling sophisticated malware such as Duqu 2.0. We discuss the gaps in current formalisations and propose the use of Attack Trees with Sequential Conjunction when it comes to analysing complex attacks. The paper models Duqu 2.0 based on the latest information sourced from formal and informal sources. This paper provides a well structured model which can be used for future analysis of Duqu 2.0 and related attacks.
Resumo:
Ab initio cross section calculations for vibronic excitation using the R -matrix approach have been performed on the N 2 + molecular ion complex. A three-state close-coupling expansion is used where the electronic target states; X 2 g + , A 2 u and B 2 u + of the molecular cation are represented by a valence configuration-interaction approximation. A non-adiabatic approximation is invoked to study vibronic excitation for the first three negative bands, (0,0), (1,0) and (2,0) of the X-B transition (B 2 u + v ´ X 2 g + v ´´ ) of N 2 + . Fixed-nuclei and non-adiabatic cross section results are compared with the available experimental data for the (0,0) band and the breakdown of the adiabatic fixed-nuclei approximation is clearly evident for the vibronic excitation of the (1,0) and (2,0) bands in this molecular ion complex.
Resumo:
The effects of diabetes mellitus on male reproductive health have not been clearly defined. A previous publication from this group reported significantly higher levels of nuclear DNA fragmentation and mitochondrial DNA deletions in spermatozoa from men with type 1 diabetes. This study compared semen profiles, sperm DNA fragmentation and levels of oxidative DNA modification in spermatozoa of diabetic and non-diabetic men. Semen samples from 12 non-diabetic, fertile men and 11 type 1 diabetics were obtained and subjected to conventional light microscopic semen analysis. Nuclear DNA fragmentation was assessed using an alkaline Comet assay and concentrations of 7,8-dihydro-8-oxo-2-deoxyguanosine (8-OHdG), an oxidative adduct of the purine guanosine, were assessed by high-performance liquid chromatography. Conventional semen profiles were similar in both groups, whilst spermatozoa from type 1 diabetics showed significantly higher levels of DNA fragmentation (44% versus 27%; P < 0.05) and concentrations of 8-OHdG (3.6 versus 2.0 molecules of 8-OHdG per 105 molecules of deoxyguanosine; P < 0.05). Furthermore, a positive correlation was observed between DNA fragmentation and concentrations of 8-OHdG per 105 molecules of deoxyguanosine (rs = 0.7, P < 0.05). The genomic damage evident in spermatozoa of type 1 diabetics may have important implications for their fertility and the outcome of pregnancies fathered by these individuals.
Resumo:
Habitual exercisers enjoy considerable protection from coronary heart disease (CHD). Often, however, only modest differences in traditional CHD risk factors are apparent between habitual exercisers and their sedentary counterparts. For this reason, there is increasing interest in novel predictors of CHD, such as a preponderance of small, dense low-density lipoprotein (LDL) particles. Polyacrylamide gel electrophoresis was used to separate lipoprotein subfractions in 32 lean exercisers, 36 lean sedentary men and 21 obese sedentary men aged 30-45 years. Well-validated equations were used to determine LDL concentration and peak particle diameter. Waist girth was used to identify lean (<100 cm) and obese ( >= 100cm) individuals. LDL concentration was lower in lean exercisers than in lean sedentary men (2.64 +/- 0.44 vs. 3.76 +/- 0.79 mmol.l(-1), p <0.001), suggesting that habitual exercise influences this risk factor. In contrast, there were no significant differences in LDL peak particle diameter between lean exercisers, lean sedentary men and obese sedentary men (27.92 +/- 0.67, 28.09 +/- 0.62 and 27.77 +/- 0.77 nm, respectively). In multiple linear regression analysis, triglyceride concentration was the only significant predictor of LDL PPD. These data suggest that habitual exercise influences LDL concentration but does not influence LDL particle size in men aged 30-45 years.
Resumo:
Aim: To determine if serum pigment epithelium-derived factor (PEDF) levels in Type 2 diabetes are related to vascular risk factors and renal function. Methods: PEDF was quantified by ELISA in a cross-sectional study of 857 male Veterans Affairs Diabetes Trial (VADT) subjects, and associations with cardiovascular risk factors and renal function were determined. In a subset (n = 246) in whom serum was obtained early in the VADT (2.0 ± 0.3 years post-randomization), PEDF was related to longitudinal changes in renal function over 3.1 years. Results: Cross-sectional study: In multivariate regression models, PEDF was positively associated with serum triglycerides, waist-to-hip ratio, serum creatinine, use of ACE inhibitors or angiotensin receptor blockers, and use of lipid-lowering agents; it was negatively associated with HDL-C (all p < 0.05). Longitudinal study: PEDF was not associated with changes in renal function over 3.1 years (p > 0.09). Conclusions: Serum PEDF in Type 2 diabetic men was cross-sectionally associated with dyslipidemia, body habitus, use of common drugs for blood pressure and dyslipidemia, and indices of renal function; however, PEDF was not associated with renal decline over 3.1 years.
Resumo:
BACKGROUND: Dietary cocoa is an important source of flavonoids and is associated with favorable cardiovascular disease effects, such as improvements in vascular function and lipid profiles, in nondiabetic adults. Type 2 diabetes (T2D) is associated with adverse effects on postprandial serum glucose, lipids, inflammation, and vascular function.
OBJECTIVE: We examined the hypothesis that cocoa reduces metabolic stress in obese T2D adults after a high-fat fast-food-style meal.
METHODS: Adults with T2D [n = 18; age (means ± SEs): 56 ± 3 y; BMI (in kg/m(2)): 35.3 ± 2.0; 14 women; 4 men) were randomly assigned to receive cocoa beverage (960 mg total polyphenols; 480 mg flavanols) or flavanol-free placebo (110 mg total polyphenols; <0.1 mg flavanols) with a high-fat fast-food-style breakfast [766 kcal, 50 g fat (59% energy)] in a crossover trial. After an overnight fast (10-12 h), participants consumed the breakfast with cocoa or placebo, and blood sample collection [glucose, insulin, lipids, and high-sensitivity C-reactive protein (hsCRP)] and vascular measurements were conducted at 0.5, 1, 2, 4, and 6 h postprandially on each study day. Insulin resistance was evaluated by homeostasis model assessment.
RESULTS: Over the 6-h study, and specifically at 1 and 4 h, cocoa increased HDL cholesterol vs. placebo (overall Δ: 1.5 ± 0.8 mg/dL; P ≤ 0.01) but had no effect on total and LDL cholesterol, triglycerides, glucose, and hsCRP. Cocoa increased serum insulin concentrations overall (Δ: 5.2 ± 3.2 mU/L; P < 0.05) and specifically at 4 h but had no overall effects on insulin resistance (except at 4 h, P < 0.05), systolic or diastolic blood pressure, or small artery elasticity. However, large artery elasticity was overall lower after cocoa vs. placebo (Δ: -1.6 ± 0.7 mL/mm Hg; P < 0.05), with the difference significant only at 2 h.
CONCLUSION: Acute cocoa supplementation showed no clear overall benefit in T2D patients after a high-fat fast-food-style meal challenge. Although HDL cholesterol and insulin remained higher throughout the 6-h postprandial period, an overall decrease in large artery elasticity was found after cocoa consumption. This trial was registered at clinicaltrials.gov as NCT01886989.
Resumo:
Objective:
To determine whether polymorphisms in the interferon-? (IFN?)/interleukin-26 (IL-26; formerly, AK155) gene cluster contribute to sex-based differential susceptibility to rheumatoid arthritis (RA).
Methods:
Four microsatellite markers, located in a 118-kb interval that contains both the IFN? and IL-26 genes on chromosome 12q15, were typed in 251 patients with RA and 198 unrelated healthy controls (all of whom lived in Northern Ireland) by means of polymerase chain reaction–based fragment analysis.
Results:
Marker D12S2510, which is located 3 kb 3' from the IL-26 gene, was significantly associated with RA in women (corrected P [Pcorr] = 0.008, 2 degrees of freedom [2 df]) but not in men (P = 0.99, 2 df). A 3-marker haplotype, IFNGCA*13;D12S2510*8;D12S2511*9, was inferred that showed significant underrepresentation in women with RA (odds ratio 0.50, 95% confidence interval 0.32–0.78; P = 0.002, Pcorr = 0.03) but not in men with RA.
Conclusion:
Our results demonstrate that common polymorphisms in the IFN?/IL-26 gene region may contribute to sex bias in susceptibility to RA, by distorting the propensity of female carriers versus male carriers to contract this disease. These results conform to our recent observations of a role for this gene cluster in sex-based differential susceptibility to another Th1-type inflammatory disease, multiple sclerosis.
Resumo:
BACKGROUND Diabetes mellitus (DM) is increasing in men of reproductive age. Despite this, the prevalence of diabetes in men attending fertility clinics is largely unknown. Furthermore, studies examining the effects of DM on sperm fertility potential have been limited to conventional semen analysis. METHODS Conventional semen analysis (semen volume, sperm count, motility and morphology) was performed for 27 diabetic (mean age 34 +/- 2 years) and 29 non-diabetic subjects (control group, men undergoing routine infertility investigations, mean age 33 +/- 1 years). Nuclear DNA (nDNA) fragmentation was assessed using the alkaline Comet assay and mitochondrial DNA (mtDNA) deletions by Long-PCR. RESULTS Other than a small, but significant, reduction in semen volume in diabetic men (2.6 versus 3.3 ml; P <0.05), conventional semen parameters did not differ significantly from control subjects. Diabetic subjects had significantly higher mean nDNA fragmentation (53 versus 32%; P <0.0001) and median number of mtDNA deletions (4 versus 3; P <0.05) compared with control subjects. CONCLUSIONS Diabetes is associated with increased sperm nuclear and mtDNA damage that may impair the reproductive capability of these men.
Resumo:
During bone development and repair, angiogenesis, osteogenesis and bone remodelling are closely associated processes that share some common mediators. In the present study non-adherent human bone marrow mononuclear cells under the induction of sRANKL and M-CSF, differentiated into osteoclasts with TRAP positive staining, VNR expression, and Ca-P resorptive activity. The effects of various combinations of rhBMP-2 (0, 3, 30, 300 ng/ml) and rhVEGF (0, 25 ng/ml) on osteoclastogenesis potentials were examined in this experimental system. The percentages of TRAP-positive multiple nucleated cells represent osteoclast differentiation potential and the percentages of resorptive areas in the Ca-P coated plates resemble osteoclast resorption capability. The presence of rhBMP-2 at 30 and 300 ng/ml showed inhibitory effects on osteoclast differentiation and their resorptive capability in the human osteoclast culture system. rhVEGF (25 ng/ml) enhanced the resorptive function of osteoclast whenever it was used alone or combined with 3 ng/ml rhBMP-2. However, rhVEGF induced resorptive function was inhibited by 30 ng/ml and 300 ng/ml rhBMP-2 at a dose-dependent manner. Statistical analysis demonstrated that an interactive effect exists between rhBMP-2 and rhVEGF on human osteoclastogenesis. These findings suggested that an interactive regulation may exist between BMPs and VEGF signaling pathways during osteoclastogenesis, exact mechanisms are yet to be elucidated.
Resumo:
The electrochemical oxidation of potassium nitrite has been studied in the room temperature ionic liquid (RTIL) [C(2)mim][NTf2] by cyclic voltammetry at platinum electrodes. A chemically irreversible oxidation peak was observed, and a solubility of 7.5(+/- 0.5) mM and diffusion coefficient of 2.0(+/- 0.2) x 10(-11) m(2) s(-1) were calculated from potential step chronoamperometry on the microdisk electrode. A second, and sometimes third, oxidation peak was also observed when the anodic limit was extended, and these were provisionally assigned to the oxidation of nitrogen dioxide (NO2) and nitrate (NO3-), respectively. The electrochemical oxidation of nitrogen dioxide gas (NO2) was also studied by cyclic voltammetry in [C(2)mim][NTf2] on Pt electrodes of various size, giving a solubility of ca. 51(+/- 0.2) mM and diffusion coefficient of 1.6(+/- 0.05) x 10(-10) m(2) s(-1) (at 25 degrees C). It is likely that NO2 exists predominantly as its dimer, N2O4, at room temperature. The oxidation mechanism follows a CE process, which involves the initial dissociation of the dimer to the monomer, followed by a one-electron oxidation. A second, larger oxidation peak was observed at more positive potentials and is thought to be the direct oxidation of N2O4. In addition to understanding the mechanisms of NO2- and NO2 oxidations, this work has implications in the electrochemical detection of nitrite ions and of NO2 gas in RTIL media, the latter which may be of particular use in gas sensing.