547 research outputs found
Tracking Holocene palaeostratification and productivity changes in the Western Irish Sea: A multi-proxy record
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The Western Irish Sea preserves an exceptionally thick (ca. 40 m) Holocene succession that is ideally suited to understanding the pattern of palaeostratification and water mass productivity changes in the region, and their relationship with sea level, sedimentation, and biota. Additionally, the presence of shallow-buried methane provides an opportunity to explore its potential impact on the local pattern of Holocene marine environmental change. Multi-proxy investigation of a cored borehole succession through the Holocene interval tracks changes from mixed to seasonally stratified conditions. In the earliest Holocene (11.2–10 ka), high productivity, mixed water conditions prevailed, with abundant and diverse foraminifera and dominant heterotrophic dinoflagellate cysts. Productivity was probably driven by high nutrient fluxes related to high rates of sedimentation (>1600 cm/kyr), in turn influenced by relatively low sea level and restricted sediment accommodation space across shelf areas to the east of the borehole site (eastern Irish Sea Basin). With rising sea level in the later part of the Early Holocene, the region evolved into a relatively lower productivity mixed water mass system, with significant changes in ecology revealed by dinoflagellate cysts and foraminifera. In the latest Early Holocene and earliest Mid Holocene (ca. 8.4–8.2 ka) a return to higher productivity is signalled by dinoflagellate cyst data; a result of seasonal stratification becoming established, evidenced by sharply increased summer sea surface temperature estimates (typically 16–17 °C) that contrast with an opposite (more positive) trend in δ18O values for benthic foraminifera. Reductions in turbulent mixing associated with stratification might have exacerbated the palaeoecological impact of shallow-buried methane associated with the borehole site, potentially evidenced by a significant change in dominant benthic foraminifera and strong, localised excursions in the benthic δ13C/δ18O record
The development and implementation of a regional network of physiotherapists for exercise therapy in patients with peripheral arterial disease, a preliminary report
BACKGROUND: Exercise therapy (ET) is the main conservative and proven effective treatment of patients with intermittent claudication. Currently, the most frequent exercise prescription is a single 'go home and walk' advise, without supervision or follow-up. There is no evidence to support the efficacy of this advise and compliance is known to be low. Therefore, a systematic approach was used to guarantee quality and standardisation of treatment, optimal guideline adherence and improved of inter-professional communication between vascular surgeons and physiotherapists. In this preliminary report we would like to outline the steps taken for the development and implementation of the Network Exercise Therapy Parkstad METHODS: In October 2003 all 59 regional physiotherapy practices were invited to attend a symposium regarding ET in a physiotherapeutic setting. Attending physiotherapists interested in providing ET and willing to follow a certified course on ET, were asked to register. Three tastkgroups were formed to accomplish the set targets: Exercise therapy education, Exercise therapy implementation and continuity, and Inter-professional communication in the Parkstad region. RESULTS: In total 27 physiotherapists, from 22 different practices followed the educational program and are now trained and accredited to provide ET according to the guideline of the Royal Dutch Society for Physiotherapy. A web-based database wasdesigned to contain information on disease specific items provided by the vascular surgery department, and aspects with respect to ET registered by the physiotherapist. The information is regularly updated and available online. Access tothe database is restricted to vascular surgeons and physiotherapists in the network. The secondary purpose of the database is to register essential benchmark data for future analysis of ET in a physiotherapeutic setting in the Netherlands and to enable physiotherapists continuous feedback on patient performance. A triage system was developed to detect patients with a compromised cardiac history. This group receives ET at the in-hospital department of revalidation with the possibility of immediate consultation of a cardiologist in case of cardiac complications or even CPR. CONCLUSION: The Network Exercise Therapy Parkstad of supervised ET is the first initiative in the Netherlands to provide ET close to the patient's home environment. With the implementation of supervised ET in an outpatient physiotherapeutic setting for all eligible patients with symptomatic PAD, the access to care has been improved. A web-based communication system provides physiotherapists and vascular surgeons with all the necessary and continues updated patient information. Future research, currently in progress, will investigate the therapeutic benefits and cost-effectiveness of exercise therapy in a physiotherapeutic setting
LKB1 as the ghostwriter of crypt history
Familial cancer syndromes present rare insights into malignant tumor development. The molecular background of polyp formation and the cancer prone state in Peutz-Jeghers syndrome remain enigmatic to this day. Previously, we proposed that Peutz-Jeghers polyps are not pre-malignant lesions, but an epiphenomenon to the malignant condition. However, Peutz-Jeghers polyp formation and the cancer-prone state must both be accounted for by the same molecular mechanism. Our contribution focuses on the histopathology of the characteristic Peutz-Jeghers polyp and recent research on stem cell dynamics and how these concepts relate to Peutz-Jeghers polyposis. We discuss a protracted clonal evolution scenario in Peutz-Jeghers syndrome due to a germline LKB1 mutation. Peutz-Jeghers polyp formation and malignant transformation are separately mediated through the same molecular mechanism played out on different timescales. Thus, a single mechanism accounts for the development of benign Peutz-Jeghers polyps and for malignant transformation in Peutz-Jeghers syndrome
A bovine lymphosarcoma cell line infected with theileria annulata exhibits an irreversible reconfiguration of host cell gene expression
Theileria annulata, an intracellular parasite of bovine lymphoid cells, induces substantial phenotypic alterations to its host cell including continuous proliferation, cytoskeletal changes and resistance to apoptosis. While parasite induced modulation of host cell signal transduction pathways and NFκB activation are established, there remains considerable speculation on the complexities of the parasite directed control mechanisms that govern these radical changes to the host cell. Our objectives in this study were to provide a comprehensive analysis of the global changes to host cell gene expression with emphasis on those that result from direct intervention by the parasite. By using comparative microarray analysis of an uninfected bovine cell line and its Theileria infected counterpart, in conjunction with use of the specific parasitacidal agent, buparvaquone, we have identified a large number of host cell gene expression changes that result from parasite infection. Our results indicate that the viable parasite can irreversibly modify the transformed phenotype of a bovine cell line. Fifty percent of genes with altered expression failed to show a reversible response to parasite death, a possible contributing factor to initiation of host cell apoptosis. The genes that did show an early predicted response to loss of parasite viability highlighted a sub-group of genes that are likely to be under direct control by parasite infection. Network and pathway analysis demonstrated that this sub-group is significantly enriched for genes involved in regulation of chromatin modification and gene expression. The results provide evidence that the Theileria parasite has the regulatory capacity to generate widespread change to host cell gene expression in a complex and largely irreversible manner
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