25,389 research outputs found
Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea
Pacific oysters (Crassostrea gigas) were first observed in the Dutch Wadden Sea near Texel in 1983. The population increased slowly in the beginning but grew exponentially from the mid-1990s onwards, although now some stabilisation seems to be occurring. They occur on a variety of substrates such as mussel beds (Mytilus edulis), shell banks, dikes and poles. After initial settlement spat may fall on older individuals and congregate to dense clumps and subsequently form reefs. Individual Pacific oysters grow 3–4 cm long in their first year and 2–3 cm in their second year. Many mussel beds (Mytilus edulis) are slowly taken over by Pacific oysters, but there are also several reports of mussel spat settling on Pacific oyster reefs. This might in the end result in combined reefs. Successful Pacific oyster spat fall seems to be related to high summer temperatures, but also after mild summers much spat can be found on old (Pacific oyster) shells. Predation is of limited importance. Mortality factors are unknown, but every now and then unexplained mass mortality occurs. The gradual spread of the Pacific oyster in the Dutch Wadden Sea is documented in the first instance based on historical and anecdotal information. At the start of the more in-depth investigation in 2002, Pacific oysters of all size classes were already present near Texel. Near Ameland the development could be followed from the first observed settlement. On dense reefs each square metre may contain more than 500 adult Pacific oysters, weighing more than 100 kg per m² fresh weigh
Involvement of autophagy in the effect of exercise on left ventricular hypertrophy induced by high fat diet in rats
Chaired Posters PresentationObjectives: Left ventricular hypertrophy (LVH) associated with obesity
increases the morbidity and mortality of cardiovascular disease, which could
be attenuated by exercise in overweight and hypertensive patients. The
lysosomal degradation pathway − autophagy is reportedly mediated the
beneficial effect of exercise on glucose and lipid homeostasis. The present
study aimed to investigate the involvement of autophagy in the effect of
exercise on LVH induced by high fat diet in rats.
Methods: Female adult SD rats were divided into 4 groups namely: (i) high
fat diet (HFD), (ii) HFD+exercise, (iii) exercise, (iv) control. Rats in the
HFD groups were orally fed with high-fat chow (30% fat) daily for 12 weeks,
and rats in the exercise groups had exercise with a motorized wheel in the
last 4 weeks. Noninvasive measures of systolic pressure and fat composition
were assessed, respectively by tail cuff and MRI. The expression of markers
for cardiac hypertrophy and the protein expression in autophagic pathway
were determined by quantitative real time-PCR and western blot, respectively.
Statistical significance was at p<0.05 with ANOVA analysis followed by
post-hoc tests.
Results: Rats fed with HFD had LVH (increased heart weight and LV/
RV+septum ratio) with higher levels of body weight, arterial pressures and
fat composition than that of the control rat. In addition, the QTc interval and
the diameter and disarray of ventricular myocytes were significantly
increased in the HFD group, supported by elevated levels of the expression
of hypertrophic markers (ANP, BNP, β-MHC). These parameters were
attenuated by exercise in the HFD-fed rats. Moreover, we found elevated
levels of LC3II in the HFD heart, which were also attenuated by exercise,
suggesting an involvement of autophagy in the beneficial effect of exercise.
Furthermore, the expression level of AMPKα was also increased in the
exercise groups.
Conclusion: We demonstrated that exercise lowers the body weight and
attenuates the HFD-induced LVH in rats, which probably involves autophagy.
Future studies will focus on the role of autophagy in the pathogenesis.published_or_final_versio
FooPar: A Functional Object Oriented Parallel Framework in Scala
We present FooPar, an extension for highly efficient Parallel Computing in
the multi-paradigm programming language Scala. Scala offers concise and clean
syntax and integrates functional programming features. Our framework FooPar
combines these features with parallel computing techniques. FooPar is designed
modular and supports easy access to different communication backends for
distributed memory architectures as well as high performance math libraries. In
this article we use it to parallelize matrix matrix multiplication and show its
scalability by a isoefficiency analysis. In addition, results based on a
empirical analysis on two supercomputers are given. We achieve close-to-optimal
performance wrt. theoretical peak performance. Based on this result we conclude
that FooPar allows to fully access Scala's design features without suffering
from performance drops when compared to implementations purely based on C and
MPI
Gender Differences among Sardinians with Alcohol Use Disorder
Sardinia is an Italian island in the Mediterranean characterized by secular isolation and the singular genetic characteristics of its inhabitants. Findings obtained in populations with diverse genetic make-up and cultural background indicate gender differences and/or similarities in drinking characteristics of patients with alcohol use disorder (AUD). Knowledge of these characteristics in AUD patients is useful to improve access to treatments. This paper investigated the drinking characteristics of 66 female and 282 male outpatients with AUD, born from 1937 to 1991, living in Sardinia, and compared their characteristics with those of AUD patients living in other countries. Most Sardinian patients were men, approximately 3 years younger than women; women consumed lower amounts of alcohol than men but did not differ from men in the severity of AUD. Men were more often single than women, while a higher proportion of women reported that their mother or spouse was affected by AUD. Anxiety and depression were more prevalent among women while a
higher proportion of men were affected by substance use disorders. Women were older than men at the age of first drink, regular drinking, and onset of AUD, and progressed faster than men from regular use to AUD onset. Women did not differ from men in age at first request for care, and in the lapse from AUD onset to first request for care. Women and men waited for more than 8 and 9 years, respectively, before receiving medical treatment. Gender differences progressively decreased among younger patients. Although the scarce number of women in some cohorts limits the strength of these findings, drinking characteristics of Sardinian patients did not vary significantly from those of AUD patients living in other countries. These results suggest that the number of Sardinian women with AUD is increasing and services for treatment of AUD should (a) consider women’s specific needs, and (b) realize effective policies to reduce latency prior to accessing medical treatment for both men and women with AUD
AIF-1 gene does not confer susceptibility to Behçet's disease: Analysis of extended haplotypes in Sardinian population
Background BehcEet's disease (BD) is a polygenic immune-mediated disorder characterized by a close association with the HLA-B∗51 allele. The HLA region has a strong linkage disequilibrium (LD) and carries several genetic variants (e.g. MIC-A, TNF-α genes) identified as associated to BD because of their LD with HLA-B∗51. In fact, the HLA-B∗51 is inherited as part of extended HLA haplotypes which are well preserved in patients with BD. Sardinian population is highly differentiated from other Mediterranean populations because of a distinctive genetic structure with very highly preserved HLA haplotypes. Patients and methods In order to identify other genes of susceptibility to BD within the HLA region we investigated the distribution of human Allograft Inflammatory Factor-1 (AIF-1) gene variants among BD patients and healthy controls from Sardinia. Six (rs2736182; rs2259571; rs2269475; rs2857597; rs13195276; rs4711274) AIF-1 single nucleotide polymorphisms (SNPs) and related extended haplotypes have been investigated as well as their LD within the HLA region and with HLA-B∗51. Overall, 64 BD patients, 43 HLA-B∗51 positive healthy controls (HC) and 70 random HC were enrolled in the study. Results HLA-B∗51 was the only allele with significantly higher frequency (pc = 0.0021) in BD patients (40.6%) than in HC (9.8%). The rs2259571TAIF-1 variant had a significantly reduced phenotypic, but not allelic frequency in BD patients (72.1%; pc = 0.014) compared to healthy population (91.3%). That was likely due to the LD between HLA-B∗51 and rs2259571G(pc= 9E-5), even though the rs2259571Gdistribution did not significantly differ between BD patients and HC. Conclusion No significant difference in distribution of AIF-1 SNPs haplotypes was observed between BD patients and HC and between HLA-B∗51 positive BD patients and HLA-B∗51 positive HC. Taken together, these results suggest that AIF-1 gene is not associated with susceptibility to BD in Sardinia
Evaluation of CR1 expression in neutrophils from chronic myeloid leukaemia: relationship between prognosis and cellular activity.
Why, When and How Should Clinicians Use Physiology in Patients with Acute Coronary Syndromes?
Current data support the use of coronary physiology in patients with acute coronary syndrome (ACS). In patients with ST-elevation MI, the extent of myocardial damage and microvascular dysfunction create a complex conundrum to assimilate when considering clinical management and risk stratification. In this setting, the index of microcirculatory resistance emerged as an accurate tool to identify patients at risk of suboptimal myocardial reperfusion after primary percutaneous coronary intervention who may benefit from novel adjunctive therapies. In the context of non-ST-elevation ACS, coronary physiology should be carefully interpreted and often integrated with intracoronary imaging, especially in cases of ambiguous culprit lesion. Conversely, the functional assessment of bystander coronary disease is favoured by the available evidence, aiming to achieve complete revascularisation. Based on everyday clinical scenarios, the authors illustrate the available evidence and provide recommendations for the functional assessment of infarct-related artery and non-culprit lesions in patients with ACS
The discovery, monitoring and environment of SGR J1935+2154
We report on the discovery of a new member of the magnetar class, SGR
J1935+2154, and on its timing and spectral properties measured by an extensive
observational campaign carried out between July 2014 and March 2015 with
Chandra and XMM-Newton (11 pointings). We discovered the spin period of SGR
J1935+2154 through the detection of coherent pulsations at a period of about
3.24s. The magnetar is slowing-down at a rate of 1.43(1)x10^{-11} s/s and with
a decreasing trend due to a negative second period derivative of
-3.5(7)x10^{-19} s/s^2. This implies a surface dipolar magnetic field strength
of about 2.2x10^{14} G, a characteristic age of about 3.6kyr and, a spin-down
luminosity L_{sd} of about 1.7x10^{34} erg/s. The source spectrum is well
modelled by a blackbody with temperature of about 500eV plus a power-law
component with photon index of about 2. The source showed a moderate long-term
variability, with a flux decay of about 25\% during the first four months since
its discovery, and a re-brightening of the same amount during the second four
months. The X-ray data were also used to study the source environment. In
particular, we discovered a diffuse emission extending on spatial scales from
about 1" up to at least 1' around SGR J1935+2154 both in Chandra and XMM-Newton
data. This component is constant in flux (at least within uncertainties) and
its spectrum is well modelled by a power-law spectrum steeper than that of the
pulsar. Though a scattering halo origin seems to be more probable we cannot
exclude that part, or all, of the diffuse emission is due to a pulsar wind
nebula.Comment: To appear in MNRAS; 10 pages, 3 color figures, 4 table
Exploring Chinese students’ experience of curriculum internationalisation: a comparative study of Scotland and Australia
Increasing enrolment of Chinese students has become a key feature of internationalisation for Western universities, but there is limited research into how curriculum internationalisation affects Chinese students’ learning experiences. Using the typologies of curriculum internationalisation (Edwards et al, 2003) as a framework, this paper explores and compares how Scottish and Australian universities integrate international and intercultural elements into their curriculum to support Chinese postgraduate taught students’ study. Interviews, focus groups and a survey are used as the main research methods. Analysis reveals that the practice of curriculum internationalisation in both countries is rather limited, and that Chinese students express a desire for more international perspectives in the course content, and for more mobility experiences, in order to prepare for their future careers. The mismatch between academics’ and students’ understandings of curriculum internationalisation is highlighted as an arena of power differential and an area for further study
Monocytes from infliximab-resistant patients with Crohn's disease exhibit a disordered cytokine profile
Crohn's disease (CD) is a chronic inflammatory disorder characterized by immune response dysregulation. Tumor necrosis factor-alpha (TNF alpha) is a key cytokine in the pathogenesis of CD, as indicated by the efficacy of anti-TNF-alpha therapy with infliximab (IFX). However, approximately 30-40% of CD patients fail to respond to IFX with still unclear underlying mechanisms. This study compares the inflammatory phenotype of monocytes from CD patients, who respond or non-respond to IFX. Under basal conditions, the mRNA for the cytokines TNF alpha, IL-23, IL-1 beta and the chemokines CXCL8/IL-8, CCL5/RANTES and CCL2/MCP-1 was up-regulated in monocytes from non-responders than responders. The expression of the same cytokines and CCL2/MCP-1 was higher in non-responders also upon LPS treatment. Moreover, higher secretion of TNF alpha, IL-1 beta, IFN gamma and IL-2 proteins occurred in the supernatants of LPS-treated non-responders cells. Resistance to IFX in CD may result from a transcriptional dysregulation of circulating monocytes, leading to hyperactivation of pro-inflammatory pathways. Monocytes' cytokine profile may thus represent a predictive marker of response to IFX. Monocytes were isolated from blood samples of 19 CD patients (11 responders, 8 non-responders) and incubated with or without LPS. Cytokine profiles were assessed by RT-qPCR and, in the supernatants, by ELISA assay
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