1,488 research outputs found
Thermally driven circulation in a region of complex topography: comparison of wind-profiling radar measurements and MM5 numerical predictions
The diurnal variation of regional wind patterns in the complex terrain of Central Italy was investigated for summer fair-weather conditions and winter time periods using a radar wind profiler. The profiler is located on a site where interaction between the complex topography and land-surface produces a variety of thermally and dynamically driven wind systems. The observational data set, collected for a period of one year, was used first to describe the diurnal evolution of thermal driven winds, second to validate the Mesoscale Model&nbsp;5 (MM5) that is a three-dimensional numerical model. This type of analysis was focused on the near-surface wind observation, since thermally driven winds occur in the lower atmosphere. According to the valley wind theory expectations, the site &ndash; located on the left sidewall of the valley (looking up valley) &ndash; experiences a clockwise turning with time. Same characteristics in the behavior were established in both the experimental and numerical results. <P style="line-height: 20px;"> Because the thermally driven flows can have some depth and may be influenced mainly by model errors, as a third step the analysis focuses on a subset of cases to explore four different MM5 Planetary Boundary Layer (PBL) parameterizations. The reason is to test how the results are sensitive to the selected PBL parameterization, and to identify the better parameterization if it is possible. For this purpose we analysed the MM5 output for the whole PBL levels. The chosen PBL parameterizations are: 1) Gayno-Seaman; 2) Medium-Range Forecast; 3) Mellor-Yamada scheme as used in the ETA model; and 4) Blackadar
Early Cambrian U-Pb zircon age and Hf-isotope data from the Guasayán pluton, Sierras Pampeanas, Argentina: implications for the northwestern boundary of the Pampean arc
An Early Cambrian pluton, known as the Guasayán pluton, has been identified in the central area of Sierra de Guasayán, northwestern Argentina. A U?Pb zircon Concordia age of 533 ± 4 Ma was obtained by LA-MC-ICP-MS and represents the first report of robustly dated Early Cambrian magmatism for the northwestern Sierras Pampeanas. The pluton was emplaced in low-grade metasedimentary rocks and its magmatic assemblage consists of K-feldspar (phenocrysts) + plagioclase + quartz + biotite, with zircon, apatite, ilmenite, magnetite and monazite as accessory minerals. Geochemically, the granitic rock is a metaluminous subalkaline felsic granodiorite with SiO2 = 69.24%, Na2O+ K2O = 7.08%, CaO = 2.45%, Na2O/ K2O = 0.71 and FeO/MgO = 3.58%. Rare earth element patterns show moderate slope (LaN/YbN = 8.05) with a slightly negative Eu anomalies (Eu/Eu* = 0.76). We report the first in situ Hf isotopes data (εHft = -0.12 to -4.76) from crystallized zircons in the Early Cambrian granites of the Sierras Pampeanas, helping to constrain the magma source and enabling comparison with other Pampean granites. The Guasayán pluton might provide a link between Early Cambrian magmatism of the central Sierras Pampeanas and that of the Eastern Cordillera, contributing to define the western boundary of the Pampean paleo-arc.Fil: Dahlquist, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Verdecchia, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Baldo, Edgardo Gaspar Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Basei, Miguel A. S.. Universidade Do Brasilia. Instituto de Geociencias; BrasilFil: Alasino, Pablo Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Uran, Gimena Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Rapela, Carlos Washington. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: da Costa Campos Neto, Mario. Universidade de Sao Paulo; BrasilFil: Zandomeni, Priscila Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentin
Determining the date of diagnosis – is it a simple matter? The impact of different approaches to dating diagnosis on estimates of delayed care for ovarian cancer in UK primary care
Background Studies of cancer incidence and early management will increasingly draw on routine electronic patient records. However, data may be incomplete or inaccurate. We developed a generalisable strategy for investigating presenting symptoms and delays in diagnosis using ovarian cancer as an example. Methods The General Practice Research Database was used to investigate the time between first report of symptom and diagnosis of 344 women diagnosed with ovarian cancer between 01/06/2002 and 31/05/2008. Effects of possible inaccuracies in dating of diagnosis on the frequencies and timing of the most commonly reported symptoms were investigated using four increasingly inclusive definitions of first diagnosis/suspicion: 1. "Definite diagnosis" 2. "Ambiguous diagnosis" 3. "First treatment or complication suggesting pre-existing diagnosis", 4 "First relevant test or referral". Results The most commonly coded symptoms before a definite diagnosis of ovarian cancer, were abdominal pain (41%), urogenital problems(25%), abdominal distension (24%), constipation/change in bowel habits (23%) with 70% of cases reporting at least one of these. The median time between first reporting each of these symptoms and diagnosis was 13, 21, 9.5 and 8.5 weeks respectively. 19% had a code for definitions 2 or 3 prior to definite diagnosis and 73% a code for 4. However, the proportion with symptoms and the delays were similar for all four definitions except 4, where the median delay was 8, 8, 3, 10 and 0 weeks respectively. Conclusion Symptoms recorded in the General Practice Research Database are similar to those reported in the literature, although their frequency is lower than in studies based on self-report. Generalisable strategies for exploring the impact of recording practice on date of diagnosis in electronic patient records are recommended, and studies which date diagnoses in GP records need to present sensitivity analyses based on investigation, referral and diagnosis data. Free text information may be essential in obtaining accurate estimates of incidence, and for accurate dating of diagnoses
Cancer incidence in eastern Libya: The first report from the Benghazi Cancer Registry, 2003
Cancer registration in Northern Africa is still limited and, until now, there have been no population-based data available for Libya. In this paper, we present the first data collected and analyzed by the Benghazi Cancer Registry. Registration was carried out by active data collection; the registry staff routinely visited all hospitals and pathological laboratories in eastern Libya (1.6 million inhabitants) and collected information from all death registration offices. A huge archive of prevalent cases was established before the 2003 data were collected. A total of 997 cases of primary cancers were registered among residents in 2003. The world age-standardized incidence rate for all sites combined (except non-melanoma skin) was 118 per 100,000 for men and 95 per 100,000 for women. The most frequently diagnosed malignancies in males were lung cancer (19%) and colorectal cancer (10%), followed by cancers of the head and neck (9%) and bladder (9%). Among females, they were breast cancer (26%), cancer of the colon and rectum (9%), uterus (7%) and non-Hodgkin lymphoma (5%). Our study provides data on cancer incidence in eastern Libya, and confirms that cancer incidence is much lower than in western countries. Moreover, observed patterns indicate that the incidence of many cancers, including those of the lung, breast, colon, rectum and bladder is quite different from previous estimates based on the data available from the neighboring countries. (c) 2006 Wiley-Liss, Inc
The continental assembly of SW Gondwana (Ediacaran to Cambrian): a synthesis
SW Gondwana resulted from complex interplay between continental amalgamation and
dispersal between ~ 650 and 490 Ma. The main cratons involved were Laurentia, Amazonia–
MARA (Proterozoic Maz–Arequipa–Rio Apa, Casquet et al., 2012), Kalahari, Rio de la Plata
(RPC), Congo and East Antarctica (Mawson block). Several collisional orogenic belts resulted,
notably the East Africa–Antarctica, Brasiliano–Panafrican, Pampean–Saldania, and Ross–
Delamerian orogens.
East-Antarctica broke away from the western margin of Laurentia in Rodinia. After a long drift
and counter-clockwise rotation (Dalziel, 2013) it collided with Congo and Kalahari to produce
the southern part of the left-lateral transpressional East Africa–Antarctica orogen between
580 and 550 Ma, completing the amalgamation of East Gondwana. The Trans-Antarctic
margin became an active one in the Ediacaran and subduction of the Pacific Ocean lithosphere
occurred throughout the Paleozoic, forming a tract of the Terra Australis orogen. NW–SE
directed compression in Late Cryogenian and Early Ediacaran times promoted closure of the
Adamastor Ocean, resulting in the left-lateral transpressional Brasiliano–Pan African orogeny
between 650 and 570 Ma.
The Pampean orogenic belt to the west of the RPC resulted from right-lateral collision between
Laurentia and its eastern extension MARA on the one hand and Kalahari–RPC on the other.
Ocean opening started at ~ 630 Ma and subduction and further collision took place between
540 and 520 Ma, coeval with the northward drift of Laurentia (~ 540 Ma) away from MARA
and the consequent formation of the proto-Andean margin of Gondwana. The margins of the
intervening Puncoviscana ocean were covered by Laurentia-derived siliciclastic sediments and
carbonates on the MARA side between 630 and ~ 540 Ma (Rapela et al, 2014; this symposium),
and by the marine siliciclastic Puncoviscana Formation on the other. The latter formation,
deposited between a 570 and ~530 Ma, received input from large alluvial fans descending
from juvenile Mesoproterozoic and Neproterozoic sources (new Hf isotope evidence) largely
located in the southern East Africa–Antarctica orogen. The Pampean orogen extended into
the Saldania–Gariep orogen of southern South Africa (545–520 Ma) and was apparently
discordant to the earlier Brasiliano–Pan African orogen. In late-Early to late Cambrian times the
Pampean–Saldania realm evolved into a passive margin with siliciclastic platform sedimentation.
The Pampean-Saldania realm was separated from the active Trans-Antarctic margin of East
Antarctica by an inferred transform fault in Ediacaran to Cambrian times. Regional NW–SW
shortening in the Ediacaran became N–S directed in the Cambrian, suggesting a major plate
reorganization at this time.Peer reviewe
Early mortality from colorectal cancer in England: a retrospective observational study of the factors associated with death in the first year after diagnosis
Background: The United Kingdom performs poorly in international comparisons of colorectal cancer survival with much of the deficit owing to high numbers of deaths close to the time of diagnosis. This retrospective cohort study investigates the patient, tumour and treatment characteristics of those who die in the first year after diagnosis of their disease. Methods: Patients diagnosed with colon (n=65,733) or rectal (n=26,123) cancer in England between 2006 and 2008 were identified in the National Cancer Data Repository. Multivariable logistic regression was used to investigate the odds of death within 1 month, 1-3 months and 3-12 months after diagnosis. Results: In all, 11.5% of colon and 5.4% of rectal cancer patients died within a month of diagnosis: this proportion decreased significantly over the study period. For both cancer sites, older age, stage at diagnosis, deprivation and emergency presentation were associated with early death. Individuals who died shortly after diagnosis were also more likely to have missing data about important prognostic factors such as disease stage and treatment. Conclusion: Using routinely collected data, at no inconvenience to patients, we have identified some important areas relating to early deaths from colorectal cancer, which merit further research
Emergency presentation of cancer and short-term mortality
Background:The short-term survival following a cancer diagnosis in England is lower than that in comparable countries, with the difference in excess mortality primarily occurring in the months immediately after diagnosis. We assess the impact of emergency presentation (EP) on the excess mortality in England over the course of the year following diagnosis. Methods:All colorectal and cervical cancers presenting in England and all breast, lung, and prostate cancers in the East of England in 2006-2008 are included. The variation in the likelihood of EP with age, stage, sex, co-morbidity, and income deprivation is modelled. The excess mortality over 0-1, 1-3, 3-6, and 6-12 months after diagnosis and its dependence on these case-mix factors and presentation route is then examined. Results:More advanced stage and older age are predictive of EP, as to a lesser extent are co-morbidity, higher income deprivation, and female sex. In the first month after diagnosis, we observe case-mix-adjusted excess mortality rate ratios of 7.5 (cervical), 5.9 (colorectal), 11.7 (breast ), 4.0 (lung), and 20.8 (prostate) for EP compared with non-EP. Conclusion:Individuals who present as an emergency experience high short-term mortality in all cancer types examined compared with non-EPs. This is partly a case-mix effect but EP remains predictive of short-term mortality even when age, stage, and co-morbidity are accounted for
Does dapagliflozin regress left ventricular hypertrophy in patients with type 2 diabetes?:A prospective, double-blind, randomised, placebo-controlled study
Background: Patients with diabetes have a two to fourfold increased risk for development of and death from cardiovascular disease [CVD]. The current oral hypoglycaemic agents result in limited reduction in this cardiovascular risk. Sodium glucose linked co-transporter type 2 [SGLT2] inhibitors are a relatively new class of antidiabetic agent that have been shown to have potential cardiovascular benefits. In support of this, the EMPA-REG trial showed a striking 38% and 35% reduction in cardiovascular mortality and heart failure [HF] hospitalisation respectively. The exact mechanism (s) responsible for these effects remain (s) unclear. One potential mechanism is regression of Left ventricular hypertrophy (LVH).Methods: The DAPA-LVH trial is a prospective, double-blind, randomised, placebo-controlled 'proof of concept' single-centre study that has been ongoing since January 2017. It is designed specifically to assess whether the SGLT2 inhibitor dapagliflozin regresses left ventricular [LV] mass in patients with diabetes and left ventricular hypertrophy [LVH]. We are utilising cardiac and abdominal magnetic resonance imaging [MRI] and ambulatory blood pressure monitoring to quantify the cardiovascular and systemic effects of dapagliflozin 10 mg once daily against standard care over a 1 year observation period. The primary endpoint is to detect the changes in LV mass. The secondary outcomes are to assess the changes in, LV volumes, blood pressure, weight, visceral and subcutaneous fat.Discussion: This trial will be able to determine if SGLT2 inhibitor therapy reduces LV mass in patient with diabetes and LVH thereby strengthening their position as oral hypoglycaemic agents with cardioprotective benefits.Trial Registration: Clinical Trials.gov: NCT02956811 . Registered November 2016.</p
Achieved systolic blood pressure in older people: A systematic review and meta-analysis
Background: It remains unclear into which level the systolic blood pressure (SBP) should be lowered in order to provide the best cardiovascular protection among older people. Hypertension guidelines recommendation on attaining SBP levels  33,600 participants) were included. Compared with attaining SBP levels ≥140 mmHg, levels of 130 to <140 mmHg were not associated with lower risk of outcomes in the meta-analysis of RCTs, whereas there was an associated reduction of cardiovascular mortality (RR 0.72, 95% CI 0.59-0.88) and all-cause mortality (RR 0.86, 95% CI 0.75-0.99) in the meta-analysis of post-hoc analyses or subanalyses of RCTs. Limited and conflicting data were available for the SBP levels of <130 mmHg and 140 to <150 mmHg. Conclusions: Among older people, there is suggestive evidence that achieving SBP levels of 130 to <140 mmHg is associated with lower risks of cardiovascular and all-cause mortality. Future trials are required to confirm these findings and to provide additional evidence regarding the <130 and 140 to <150 mmHg SBP levels
Left ventricular mass increases with deteriorating glucose tolerance, especially in women: Independence of increased arterial stiffness or decreased flow-mediated dilation - The Hoorn Study
OBJECTIVE - Type 2 diabetes and impaired glucose metabolism (IGM) are associated with an increased cardiovascular disease (CVD) risk. Increased left ventricular mass (LVM) is thought to increase CVD risk through several unfavorable cardiac changes. Type 2 diabetes and IGM are associated with increased LVM, but the underlying mechanism is unclear. We investigated the association between glucose tolerance status (GTS) and LVM and explored whether any such association could be mediated through increased arterial stiffness, impaired endothelial function, or the presence of atherosclerosis. RESEARCH DESIGN AND METHODS - We used ultrasound to measure LVM, carotid and femoral stiffness, carotid-femoral transit time, and flow-mediated vasodilation (FMD) and tonometry to estimate compliance and augmentation index. The study population (n = 780) consisted of 287 individuals with normal glucose metabolism (NGM), 179 with IGM, and 314 with type 2 diabetes, and the mean age was 68.4 years. RESULTS - In women, after adjusting for age, height, BMI, and mean arterial pressure, LVM increased significantly with deteriorating GTS (LVM 157 g in NGM, 155 g in IGM, and 169 g in type 2 diabetes, P for trend <0.018). Additional adjustment for arterial stiffness, FMD, or the presence of atherosclerosis did not materially alter the results, even though these variables were significantly associated with both GTS and LVM. Indexes of hyperglycemia/-insulinemia or insulin resistance explained at most 7% of the association between GTS and LVM. In men, no statistically significant associations were observed. CONCLUSIONS - Our data expand the conceptual view of the pathogenesis of GTS-related changes in LVM because we show that the increase in LVM in women is independent of increased arterial stiffness, impaired FMD, or the presence of atherosclerosis. In addition, we show that this increase in LVM is only minimally explained by indexes of hyperglycemia/-insulinemia or insulin resistance. Our data may, in part, explain the increased CVD risk seen in women with deteriorating GTS
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