243 research outputs found
La pesca costera en la Argentina
Se aborda el estudio de la pesca costera en la Argentina (ocĂ©ano AtlĂĄntico sudoccidental) teniendo en cuenta los factores econĂłmicos, sociales y polĂticos que promovieron su retraso o desarrollo. Para comprenderlo se analizan las diversas etapas histĂłricas desde la Ă©poca de la conquista (1580) hasta nuestros dĂas. Se detalla sobre la actualidad de las artes de pesca en pequeña escala, las caracterĂsticas de los pescadores, el manejo de las pesquerĂas costeras y el conflicto por los recursos y perspectivas
Estudios ictiologicos en la laguna La Cuarentena (Isla Carabajal), rio Parana, Argentina : edad y crecimiento del "sabalo" (Prochilodus lineatus (Val.), periodo 1984-1985 (Pisces, Curimatidae)
L'objectif est de connaßtre l'ùge et la croissance du #Prochilodus lineatus$ dans la lagune La Cuarentena (31°45'15"S - 60°37'30"W) et d'établir des comparaisons avec d'autres milieux lenitiques et lotiques du Parana moyen, les échantillons ont été obtenus mensuellement (mai 1984-août 1985). On a capturé 496 exemplaires, de longueur comprise ebtre 35 et 58 cm. L'ùge a été déterminé par la lecture des écailles. On a obtenu les relations entre la longueur du poisson et le rayons des écailles et la relation longueur-poids; on a estimé la courbe de croissance théorique et le coefficient de condition (k). Les ùges obtenus sont compris entre 2 et 7 années. (Résumé d'auteur
Impact du Petit Age Glaciaire sur les plaines alluviales méditerranéenne françaises : apport de la géoarchéologie à l'évolution du bassin du Roussillon
International audienceDans la zone méditerranéenne, le Petit Age Glaciaire est enregistrée par le systÚme fluvial sous le nom bien connu de "Younger Infill". Selon des résultats récents obtenus dans le bassin du Roussillon, nous proposons une premiÚre esquisse pour le moment, a savoir les causes et les conséquences de cet épisode climatique, basé à la fois sur des données géoarchéologiques et d'archives
Rifting under steamâHow rift magmatism triggers methane venting from sedimentary basins
Factorial phase III randomised trial of rofecoxib and prolonged constant infusion of gemcitabine in advanced non-small-cell lung cancer: the GEmcitabine-COxib in NSCLC (GECO) study.
Background. The addition of cyclo-oxygenase-2 (COX-2) inhibitors and prolonged constant infusion (PCI) of gemcitabine to treatment for advanced non-small-cell lung cancer (NSCLC) might improve treatment efficacy. We aimed to assess whether the addition of rofecoxib or PCI gemcitabine could improve overall survival compared with first-line treatment with cisplatin plus gemcitabine given by standard infusion.
Methods. Patients with stage IV or IIIb (with supraclavicular nodes or pleural effusion) NSCLC who were under 70 years of age and who had performance status 0 or 1 were eligible for this multicentre, prospective, open-label, randomised phase III trial with 2Ă2 factorial design. Patients were randomly assigned to one of four treatment groups: group A,gemcitabine 1200 mg/m2 in a 30-min intravenous infusion on days 1 and 8 and intravenous cisplatin 80 mg/m2 on day 1, every 21 days for six cycles; group B, the same treatments as group A plus oral rofecoxib 50 mg/day until disease
progression; group C, intravenous PCI gemcitabine 1200 mg/m2 in a 120-min infusion on days 1 and 8 and intravenous cisplatin 80 mg/m2 on day 1, every 21 days for six cycles; group D, the same drugs as group C plus oral rofecoxib 50 mg/day until disease progression. The primary endpoint was overall survival; secondary endpoints were progression free survival, response rate, quality of life, and toxicity. Analyses were intention-to-treat. This trial is registered on the clinical trials site of the US National Institutes of Health website http://clinicaltrials.gov/ct/show/NCT00385606.
Findings. Between Jan 30, 2003, and May 3, 2005, 400 patients were enrolled. Median age was 60 years (range 29â71). PCI gemcitabine did not improve overall survival (median 47 weeks [95% CI 40â55] vs 44 [36â52], with standard gemcitabine infusion, hazard ratio (HR) of death 0·93 [0·74â1·17], p=0·41), progression-free survival, nor any other secondary endpoint. Vomiting and fatigue were significantly worse with PCI gemcitabine. The two rofecoxib groups were closed early (on Oct 1, 2004) due to withdrawal of the drug because of safety issues. With intention-to-treat statistical analyses limited to 240 patients (ie, those randomised before July 1, 2004) who had at least 3 months of treatment, rofecoxib did not prolong overall survival (median 44 weeks [CI 36â55] vs 44 [40â54] without rofecoxib, and HR of death 1·00 [0·75â1·34], p=0·85), or progression-free survival, but did improve response rate (41% vs 26%, p=0·02), global quality of life, physical, emotional and role functioning, fatigue, and sleeping. Rofecoxib significantly increased the incidence of diarrhoea and decreased constipation, fatigue, fever, weight loss, and pain, and analgesic consumption. Severe cardiac ischaemia was more frequent with rofecoxib than without; however, the diff erence was not statistically signifi cant in the primary analysis (p=0·06) and became significant when patients who were randomised between July 1, 2004, and Sept 30, 2004, were included in the analysis (p=0·03).
Interpretation. Neither PCI gemcitabine nor rofecoxib prolonged survival in the patients in this study. Rofecoxib improved response rate and several quality-of-life items, including pain-related items and global quality of life. Further studies with less cardiotoxic COX-2 inhibitors are needed in NSCLC
Birth characteristics and childhood carcinomas
BACKGROUND: Carcinomas in children are rare and have not been well studied. METHODS: We conducted a population-based caseâcontrol study and examined associations between birth characteristics and childhood carcinomas diagnosed from 28 days to 14 years during 1980â2004 using pooled data from five states (NY, WA, MN, TX, and CA) that linked their birth and cancer registries. The pooled data set contained 57â966 controls and 475 carcinoma cases, including 159 thyroid and 126 malignant melanoma cases. We used unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: White compared with âother' race was positively associated with melanoma (OR=3.22, 95% CI 1.33â8.33). Older maternal age increased the risk for melanoma (OR(per 5-year age increase)=1.20, 95% CI 1.00â1.44), whereas paternal age increased the risk for any carcinoma (OR=1.10(per 5-year age increase), 95% CI 1.01â1.20) and thyroid carcinoma (OR(per 5-year age increase)=1.16, 95% CI 1.01â1.33). Gestational age <37 vs 37â42 weeks increased the risk for thyroid carcinoma (OR=1.87, 95% CI 1.07â3.27). Plurality, birth weight, and birth order were not significantly associated with childhood carcinomas. CONCLUSION: This exploratory study indicates that some birth characteristics including older parental age and low gestational age may be related to childhood carcinoma aetiology
Multidisciplinary approach to reconstructing local pastoral activities: an example from the Pyrenean Mountains (Pays Basque)
International audienceIn this study archaeology, history and palaeoecology (modern and fossil data sets of pollen and nonpollen palynomorphs) were used to reconstruct small-scale pastoral activities in the Pyrenees Mountains during the last two millennia. Modern pollen assemblages from the major vegetation units (both natural andanthropogenic) are studied on one restricted watershed area. A correlative model (RDA) of 61 modern pollen spectra and 35 external variables distinguishes two groups of taxa, providing information on the nature and spatial extent of human impact on the landscape. The first pool indicates local pastoral activities, and the second one implies regional input from outside the studied watershed, and is not characteristic of a specific land use. These pools are described as 'Local Pastoral Pollen Indicators' (LPPI) for this particular mountain region on crystalline bedrock and 'Regional Human Activities Pollen Indicators' (RHAPI). The modern data set is used to aid interpretation of the local pollen sequence of Sourzay that covers the last 2000 calendar years BP, using RDA reconstructions, and best modern analogues as a means of comparing modern and fossil spectra. The study also demonstrates agreement between the independent interpretations of two fossil proxies, LPPI and coprophilous fungi
Reproductive factors and hormone use and risk of adult gliomas
Previous research suggests there may be a hormonal influence on glioma risk as evidenced by lower rates in females, change in incidence rates around ages at menarche and menopause and presence of hormone receptors in glial tumors. Using the large San Francisco Bay Area Adult Glioma Study, we investigated whether reported reproductive factors and hormone use were associated with gliomas overall or with histologic subtypes among female cases (n=619) and controls (n=650). We found that reproductive factors were generally not associated with gliomas. Weak to moderately elevated odds ratios were observed for self-reported later age at menarche (14+ years old versus 12â13 years old: adjusted odds ratio (AOR) = 1.39, 95% confidence interval (CI): 1.02 â1.89), particularly for non-glioblastoma histologies (AOR = 1.64, 95% CI: 1.11â2.43). Inverse associations were observed for ever self-reported use of exogenous hormones (oral contraceptive use: AOR = 0.72, 95% CI: 0.53â0.99; postmenopausal hormone use: AOR = 0.56, CI: 0.37â0.84). However, cumulative hormone exposure defined multiple ways demonstrated no clear pattern of association. The results of this study suggest that any protective effect of hormones on gliomas may be limited to exogenous hormones, but a more detailed history of exogenous hormone use are needed to confirm findings
Second-order -regularity in nonlinear elliptic problems
A second-order regularity theory is developed for solutions to a class of
quasilinear elliptic equations in divergence form, including the -Laplace
equation, with merely square-integrable right-hand side. Our results amount to
the existence and square integrability of the weak derivatives of the nonlinear
expression of the gradient under the divergence operator. This provides a
nonlinear counterpart of the classical -coercivity theory for linear
problems, which is missing in the existing literature. Both local and global
estimates are established. The latter apply to solutions to either Dirichlet or
Neumann boundary value problems. Minimal regularity on the boundary of the
domain is required. If the domain is convex, no regularity of its boundary is
needed at all
Length-weight relationships and condition factor of eight fish species inhabiting the Rocha Lagoon, Uruguay
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