191 research outputs found

    Diversity of new Martian crater clusters informs meteoroid atmospheric interactions

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    We investigated 634 crater clusters on Mars detected between 2007 and 2021, which represent more than half of all impacts discovered in this period. Crater clusters form when meteoroids in the 10 kg to 10 ton mass range break-up in Mars' atmosphere to produce a few to a few hundred fragments that hit the ground. The properties of the clusters can inform our understanding of meteoroid properties and the processes that govern their fragmentation. We mapped individual craters >>1 m within each cluster and defined a range of cluster properties based on the spatial and size distributions of the craters. The large data set, with over eight times more cluster observations than previous work, provides a more robust statistical investigation of crater cluster parameters and their correlations. Trends in size, dispersion and large crater fraction with elevation support weak atmospheric filtering of material. The diversity in the number of individual craters within a cluster, and their size-frequency distributions, may reflect either a diversity in fragmentation style, fragility or internal particle sizes.Comment: 12 pages, 12 figures at the en

    Using haloperidol as an anti-emetic in palliative care: informing practice through evidence from cancer treatment and post-operative contexts

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    YesNausea and vomiting are common symptoms in palliative care. Haloperidol is often used as an antiemetic in this context, although direct evidence supporting this practice is limited. To evaluate the efficacy and clinical use of haloperidol as an antiemetic in nonpalliative care contexts to inform practice, the authors conducted a rapid review of (i) published evidence to supplement existing systematic reviews, and (ii) practical aspects affecting the use of haloperidol including formulations and doses that are commonly available internationally. In nausea and vomiting related to cancer treatment, haloperidol was superior to control in two small studies. In postoperative nausea and vomiting (PONV), two randomized controlledtrials found treatment with haloperidol comparable to ondansetron. In palliative care, an observational study found a complete response rate of 24% with haloperidol (one in four patients) which would be consistent with a number needed to treat (NNT) of 3 to 5 derived from PONV. There remains insufficient direct evidence to definitively support the use of haloperidol for the management of nausea and vomiting in palliative care. However, generalizing evidence from other clinical contexts may have some validity

    Endogenous Galectin-9 Suppresses Apoptosis in Human Rheumatoid Arthritis Synovial Fibroblasts

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    Galectin-9 (Gal9) has been postulated to have anti-infammatory properties based on the ability of exogenous Gal9 to induce apoptosis in synovial fbroblasts in animal models of rheumatoid arthritis (RA). Here we aimed to assess the potential role of endogenous Galectins, including Gal9, in the infammatory pathology of the RA synovium in humans. Firstly expression of Galectins 1–9 was determined in synovial fbroblasts (RASF) and dermal fbroblasts (DF) isolated from RA patients, the latter representing a non-infamed site. We then further challenged the cells with pro-infammatory TLR agonists and cytokines and assessed Galectin expression. Gal9 was found to be diferentially and abundantly expressed in RASF compared to DF. Agonists of TLR3 and TLR4, along with IFNgamma were also found to induce Gal9 expression in RASF. siRNA was then used to knock-down Gal9 expression in RASF and the efects of this on apoptosis and cell viability were assessed. Increased apoptosis was observed in RASF following Gal9 knock-down. We conclude that, unlike exogenous Gal9, endogenous Gal9 is protective against apoptosis and enhances synovial fbroblast viability suggesting that its role in RA is both pathogenic and pro-infammatory

    Frequent high-level expression of the immunotherapeutic target Ep-CAM in colon, stomach, prostate and lung cancers

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    Epithelial cell adhesion molecule (Ep-CAM; CD326) is used as a target by many immunotherapeutic approaches, but little data are available about Ep-CAM expression in major human malignancies with respect to level, frequency, tumour stage, grade, histologic tumour type and impact on survival. We analysed by immunohistochemical staining tissue microarrays with 4046 primary human carcinoma samples from colon, stomach, prostate and lung cancers for both frequency and intensity of Ep-CAM expression under highly standardised conditions. A total of 3360 samples were analysable. High-level Ep-CAM expression was observed in 97.7% (n=1186) of colon, 90.7% of gastric (n=473), and 87.2% of prostate cancers (n=414), and in 63.9% of lung cancers (n=1287). No detectable Ep-CAM staining was found with only 0.4% of colon, 2.5% of gastric, 1.9% of prostate cancers, and 13.5% of lung cancers. The only significant correlation of Ep-CAM expression with tumour grading was observed in colon cancer where high-level Ep-CAM expression on grade 3 tumours was down to 92.1% (P<0.0001). Adenosquamous and squamous carcinomas of the lung had a lower percentage of high-level Ep-CAM expression compared to adenocarcinomas with 35.4 and 53.6%, respectively, and with 45.5 and 17.3% of tumours being Ep-CAM negative. With the exception of moderately differentiated colon carcinoma, where patients not expressing Ep-CAM on their tumours showed an inferior survival (P=0.0014), correlation of Ep-CAM expression with survival did not reach statistical significance for any of the other cancer indications and subgroups. In conclusion, the data strongly support the notion that Ep-CAM is a prime target for immunotherapies in major human malignancies. This is because the most common human cancers show (i) a low frequency of Ep-CAM-negative tumours, (ii) a high frequency of Ep-CAM expression on cells of a given tumour, and (iii) for most cancers, an insignificant influence of tumour staging, grading and histology on Ep-CAM expression

    Integrins as therapeutic targets: lessons and opportunities.

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    The integrins are a large family of cell adhesion molecules that are essential for the regulation of cell growth and function. The identification of key roles for integrins in a diverse range of diseases, including cancer, infection, thrombosis and autoimmune disorders, has revealed their substantial potential as therapeutic targets. However, so far, pharmacological inhibitors for only three integrins have received marketing approval. This article discusses the structure and function of integrins, their roles in disease and the chequered history of the approved integrin antagonists. Recent advances in the understanding of integrin function, ligand interaction and signalling pathways suggest novel strategies for inhibiting integrin function that could help harness their full potential as therapeutic targets

    Constitutional dynamics and partisan conflict:A comparative assessment of multi-level systems in Europe

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    publication-status: Publishedtypes: ArticleThe case studies revealed that the constitutional nature of a multi-level system indeed shapes its modes of day-to-day intergovernmental coordination and, with it, the way competences are (re)allocated in the longer term. Both in federal arrangements and in confederations, the ‘subunits’ – whose status is constitutionally protected – could more easily defend their decision-making capacity within their areas of jurisdiction because they can veto changes in the allocation of competences, an advantage lower-level governments in regionalized systems do not enjoy. Similarly, in federal and confederal systems day-to-day interaction in Inter Governmental Relations (IGR) predominantly took place in multilateral structures, while in regionalized systems bilateralism was more pronounced. The relative influence of party-political (in)congruence on IGR, in contrast, was more varied than theoretically expected

    Processos de democracia direta: sim ou não? Os argumentos clássicos à luz da teoria e da prática

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    Regularmente surgem controvérsias sobre os processos de democracia direta, dos quais os mecanismos mais frequentes são a iniciativa popular, o plebiscito e o referendo. Por um lado, há autores que defendem a posição de que essas instituições tornam o jogo político mais lento, caro, confuso e ilegítimo; outros defendem a posição contrária e argumentam que processos de democracia direta são fundamentais para os cidadãos e a qualidade da democracia. O presente estudo analisa esse tema em torno de sete questões, baseadas em considerações teóricas e pesquisas empíricas: 1. A questão entre o minimalismo e o maximalismo democrático; 2. A concorrência entre maioria e minoria; 3. A concorrência entre as instituições representativas e os processos de democracia direta; 4. A questão da competência dos cidadãos; 5. A questão dos efeitos colaterais dos processos de democracia direta; 6. A questão do tamanho do eleitorado; 7. A questão dos custos dos processos de democracia direta. As sete questões são analisadas a partir de uma revisão bibliográfica que considera tanto fontes nacionais como internacionais. O estudo mostra que os processos de democracia direta podem ser um complemento para as instituições representativas em um sistema democrático. O bom desempenho dos plebiscitos, referendos e iniciativas populares depende tanto da regulamentação destes como também do desempenho das outras instituições políticas e da situação socioeconômica de um país. O estudo permite ampliar e aprofundar o debate sobre processos de democracia direta no Brasil
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