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Historical Series (historical + series)
Selected AbstractsDowny mildew (Plasmopara viticola) epidemics on grapevine under climate changeGLOBAL CHANGE BIOLOGY, Issue 7 2006SALINARI FRANCESCA Abstract As climate is a key agro-ecosystem driving force, climate change could have a severe impact on agriculture. Many assessments have been carried out to date on the possible effects of climate change (temperature, precipitation and carbon dioxide concentration changes) on plant physiology. At present however, likely effects on plant pathogens have not been investigated deeply. The aim of this work was to simulate future scenarios of downy mildew (Plasmopara viticola) epidemics on grape under climate change, by combining a disease model to output from two general circulation models (GCMs). Model runs corresponding to the SRES-A2 emissions scenario, characterized by high projections of both population and greenhouse gas emissions from present to 2100, were chosen in order to investigate impacts of worst-case scenarios, among those currently available from IPCC. Three future decades were simulated (2030, 2050, 2080), using as baseline historical series of meteorological data collected from 1955 to 2001 in Acqui Terme, an important grape-growing area in the north-west of Italy. Both GCMs predicted increase of temperature and decrease of precipitation in this region. The simulations obtained by combining the disease model to the two GCM outputs predicted an increase of the disease pressure in each decade: more severe epidemics were a direct consequence of more favourable temperature conditions during the months of May and June. These negative effects of increasing temperatures more than counterbalanced the effects of precipitation reductions, which alone would have diminished disease pressure. Results suggested that, as adaptation response to future climate change, more attention would have to be paid in the management of early downy mildew infections; two more fungicide sprays were necessary under the most negative climate scenario, compared with present management regimes. At the same time, increased knowledge on the effects of climate change on host,pathogen interactions will be necessary to improve current predictions. [source] Do anticoagulants improve survival in patients presenting with venous thromboembolism?JOURNAL OF INTERNAL MEDICINE, Issue 6 2003J. Kelly Abstract. Anticoagulants have been available since around 1940 and have become the standard of treatment for venous thromboembolism (VTE) for over four decades. However, as with other treatments which became established before the evidence-based era, there is a paucity of evidence from randomized controlled trials validating their effectiveness in preventing the most feared complication of VTE, recurrent fatal pulmonary embolism (PE). Only two such trials have been performed, the results of which conflict. The bulk of data supporting their use are derived from three sources. First, studies of thromboprophylaxis, and comparisons of shorter and longer courses of anticoagulants in high-risk patients with established VTE have clearly demonstrated their effectiveness in primary and late secondary prevention. Given that heparin has an immediate onset of action, anticoagulants should therefore also be effective in early secondary prevention, the proposed mechanism of action in the acute treatment of VTE. Secondly, studies of inadequately treated patients have consistently shown higher recurrence rates than in those adequately treated. Finally, comparisons of outcomes in untreated and treated historical series, and of untreated historical series to treated series in the modern era have shown substantially lower rates of fatal PE in anticoagulated patients. Because these differences are so marked, harmonize with our current understanding of the mechanism of action of anticoagulants and are supported by other evidence, it is much more likely that they at least partly reflect the effectiveness of anticoagulants as opposed to being explicable purely in terms of accumulated biases and a changing distribution of disease severity. [source] The efficiency of natural gas futures marketsOPEC ENERGY REVIEW, Issue 2 2003Ahmed El Hachemi Mazighi Recent experience with the emergence of futures markets for natural gas has led to many questions about the drivers and functioning of these markets. Most often, however, studies lack strong statistical support. The objective of this article is to use some classical statistical tests to check whether futures markets for natural gas (NG) are efficient or not. The problem of NG market efficiency is closely linked to the debate on the value of NG. More precisely, if futures markets were really efficient, then: 1) spot prices would reflect the existence of a market assessment, which is proof that speculation and the manipulation of prices are absent; 2) as a consequence, spot prices could give clear signals about the value of NG; and 3) historical series on spot prices could serve as "clean" benchmarks in the pricing of NG in long-term contracts. On the whole, since the major share of NG is sold to power producers, the efficiency of futures markets implies that spot prices for NG are driven increasingly by power prices. On the other hand, if futures markets for natural gas fail the efficiency tests, this will reflect: 1) a lack of liquidity in futures markets and/or possibilities of an excess return in the short term; 2) a pass-through of the seasonality of power demand in the gas market; 3) the existence of a transitory process, before spot markets become efficient and give clear signals about the value of NG. Using monthly data on three segments of the futures markets, our findings show that efficiency is almost completely rejected on both the International Petroleum Exchange in London (UK market) and the New York Mercantile Exchange (US market). On the NYMEX, the principle of "co-movement" between spot and forward prices seems to be respected. However, the autocorrelation functions of the first differences in the price changes show no randomness of price fluctuations for three segments out of four. Further, both the NYMEX and the IPE fail, with regard to the hypothesis that the forward price is an optimal predictor of the spot price. Consequently, unless we have an increase in the liquidity of spot markets and an increase in the relative share of NG spot trading, futures markets cannot be considered as efficient. [source] Primary breast non-Hodgkin's lymphoma: A large single center study of initial characteristics, natural history, and prognostic factors,AMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2009Patricia Validire The aims of this study were to define the initial pathological and clinical characteristics, and prognostic factors of patients with primary breast malignant lymphoma (PBL). All patients treated at the Institut Curie for lymphoma with breast involvement were reviewed. A pathological review of all cases was performed. Forty-five cases were selected in whom 38 cases were of diffuse large B-cell lymphoma. A complete analysis was then performed on these 38 patients. Twenty out of 28 cases (71%) of cases were Bcl-2 positive and four out of 28 (14%) had a CD10 positive staining. Peculiar initial characteristics showed nodal involvement in 58% of the cases and two or more extra-nodal sites in 31% of the cases. Among the 37 patients for whom all data were available, and according to the International Prognostic Index, 19 patients (51%) were classified in the low-risk group, 5 cases (14%) in the low- to intermediate-risk group, 6 patients (16%) in the intermediate- to high-risk group, and 7 (19%) case in the high-risk group. At the end of initial therapy, 34 patients (89%) achieved CR. With a median follow-up of 96 months, 18 patients (47%) relapsed of whom 3 had a relapse in central nervous system site. The 5-year disease-free (DFS) and overall survivals (OS) were 54% and 61%, respectively. In multivariate analysis, the presence of 2 or more extranodal sites was prognostic for lower DFS (P = 0.0008) and OS (P = 0.09), and a performance status ,1 was prognostic for lower OS (P = 0.005). Finally, when our series was compared with a historical series of 111 patients with aggressive nodal lymphomas, we observed significant lower survival rates in localized PBL (P < 0.03). Initial breast localization has a pejorative impact on the outcome of patients with Non-Hodgkin's Lymphoma (NHL), with an impressive adverse influence of additional extranodal sites. These results suggest a specific management of NHL with breast involvement. Am. J. Hematol., 2009. © 2008 Wiley-Liss, Inc. [source] Laparoscopic debulking of bulky lymph nodes in women with cervical cancer: indication and surgical outcomesBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2009R Tozzi Objective, To describe the technique and the surgical outcome of laparoscopic resection of bulky lymph nodes before adjuvant treatment. Design, Prospective pilot study. Setting, Gynaecological oncology cancer centre. Population, From January 2006 to February 2008, 22 consecutive women presented with cervical cancer and bulky metastatic lymph nodes (>2 cm). Methods, All women underwent resection of bulky lymph nodes by laparoscopy. A prospective record of the main surgical outcomes was performed. Main outcome measures, Safety and efficacy of laparoscopic resection of bulky lymph nodes, conversion to laparotomy, intra- and perioperative morbidity. Results, All the operations were completed by laparoscopy. Median operative time was 197 minutes (range 180,320). Median blood loss was 60 cc (range 10,100), two women experienced complications: one thermal injury of the sciatic root provoking postoperative leg palsy and one chylous ascites. The woman with the thermal injury has recovered most leg function with physiotherapy and the woman with chylous ascites recovered within 2 weeks, slightly delaying the adjuvant treatment. All women were discharged within 4 days from the operation (range 2,4). Pathology reports confirmed the presence of tumour metastases and the lymph nodes size. The adjuvant treatment started at a median time of 12 days (range 3,22). Conclusion, Debulking of large pelvic and para-aortic lymph nodes was effectively accomplished by laparoscopy in all 22 women with 9% complication rate. The surgical outcome is similar to historical series on women operated on by laparotomy, with the advantage of a faster recovery and an early start of adjuvant treatment. [source] | ||||||||||