996 resultados para Lake on the Mountain
Resumo:
The Mediterranean is regarded as a region of intense climate change. To better understand future climate change, this area has been the target of several palaeoclimate studies which also studied stable isotope proxies that are directly linked to the stable isotope composition of water, such as tree rings, tooth enamel or speleothems. For such work, it is also essential to establish an isotope hydrology framework of the region of interest. Surface waters from streams and lakes as well as groundwater from springs on the island of Corsica were sampled between 2003 and 2009 for their oxygen and hydrogen isotope compositions. Isotope values from lake waters were enriched in heavier isotopes and define a local evaporation line (LEL). On the other hand, stream and spring waters reflect the isotope composition of local precipitation in the catchment. The intersection of the LEL and the linear fit of the spring and stream waters reflect the mean isotope composition of the annual precipitation (dP) with values of -8.6(±0.2) per mil for d18O and -58(±2) per mil for d2H. This value is also a good indicator of the average isotope composition of the local groundwater in the island. Surface water samples reflect the altitude isotope effect with a value of -0.17(±0.02) per mil per 100 m elevation for oxygen isotopes. At Vizzavona Pass in central Corsica, water samples from two catchments within a lateral distance of only a few hundred metres showed unexpected but systematic differences in their stable isotope composition. At this specific location, the direction of exposure seems to be an important factor. The differences were likely caused by isotopic enrichment during recharge in warm weather conditions in south-exposed valley flanks compared to the opposite, north-exposed valley flanks.
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The Padul-Nigüelas Fault Zone (PNFZ) is situated at the south-western mountain front of the Sierra Nevada (Spain) in an extensive regime and belongs to the internal zone of the Betic Cordilleras. The aim of this study is a collection of new evidence for neotectonic activity of the fault zone with classical geological field work and modern geophysical methods, such as ground penetrating radar (GPR). Among an apparently existing bed rock fault scarp with triangular facets, other evidences, such as deeply incised valleys and faults in the colluvial wedges, are present in the PNFZ. The preliminary results of our recent field work have shown that the synsedimentary faults within the colluvial sediments seem to propagate basinwards and the bed rock fault is only exhumed due to erosion for the studied segment (west of Marchena). We will use further GPR data and geomorphologic indices to gather further evidences of neotectonic activity of the PNFZ.
Resumo:
Climate warming is predicted to increase summer air temperatures in the Arctic, warming soils and enhancing microbial decomposition of soil organic matter. Given the size of the soil carbon stores in the Arctic, even a fraction of its release as CO2 to the atmosphere could result in a positive feedback to climate warming. Fertilizers have been used in the past to quickly increase soil solution nutrients pools to mimic predicted concentrations under climate warming. However, because it may have inadvertent affects on the soil microbial community, fertilizer-induced patterns in microbial decomposition may be unrealistic. This study aimed to better understand the proposed mechanism of enhanced microbial decomposition under nutrient addition and warming treatments to discern whether warming alone is enough to stimulate enhanced microbial decomposition, or if nutrients in excess (i.e. chronic high nutrient additions) are necessary to yield such a response. I investigated the impacts of 10 years of greenhouse summer warming, chronic low nutrient factorial addition (5 g N and 1g P m-2 year-1, respectively), and chronic high nutrient factorial addition (10 g N and 5g P m-2 year-1, respectively) treatments on a mesic birch hummock tundra ecosystem near Daring Lake, NWT, Canada. Soil microbial nutrient pools, soil solution nutrient pools, and microbial community structure were measured in the upper organic, lower organic, and uppermost mineral soil depth intervals of all treatment plots in Spring 2014. Interestingly, the low nutrient additions did not yield any significant trends, yet the warming treatment increased soil bacterial richness suggesting a legacy effect of warming from the previous summers. Enhanced microbial nutrient uptake occurred only in the high nutrient addition treatments, and did not significantly alter soil carbon at least within the ten year period of this experiment. Together, these results and the absence of significant impacts of the low nutrient and greenhouse warming treatments suggests that nutrient and carbon cycling in these low arctic soils may be resilient against climate warming, at least over the initial decades.
Resumo:
Quintus Curtius found in his sources a speech where a Scythian censured Alexander, followed by the King’s reply. Curtius drastically abridged this second discourse in order to highlight the criticism of the Macedonian. The Scythian’s words have a striking rhetorical language and some allusions taken from Greek literature, in addition to possible indirect references to Caligula. Curtius declares that he follows his source word-for-word aiming to justify these inconsistencies, but also trying to hide the manipulations he has done to achieve his own narrative purposes.
Resumo:
This paper is based on a two year's intensive statistical data collection survey on Lake Kyoga, observations made on Lake Victoria over the last decade occasional visits on Lake Albert (Mobutu) and Lake Malawi. World over, scientists have kept doubting the fisheries statistical figures presented by various African countries. Some countries fail to present any figures. This paper, therefore, narrates most of the causes and possible solutions to those problems.
Resumo:
Reports of hydrilla (Hydrilla verticilata) infestation lakes Bisina and Opeta were verbally communicated by some members of FIRRI who undertook surveys during the LVEMP 1 phase (1997 to 2004) to assess the diversity and stocks of fishes in the Kyoga basin satellite lakes. This issue was taken up by FIRRI and NAARI staff who work on aquatic weeds management to ascertain and quantify the presence of H. verticilata and other aquatic weeds, with the sole aim of finding ways and means of controlling one of the world's worst aquatic weeds, H. verticilata.The survey on Lake Opeta indicated that this weed was rare since only a few small broken pieces were sited at the lake's outflow through an extensive wetland to Lake Bisina. It was therefore concluded that it was not economically viable to allocate resources for further survey of H. verticilata on Lake Opeta. This finding therefore discredited the previous (informal) reports that H. verticilata was well established on Lake Opeta. It should be noted that the reports came from scientists who were not well versed with systematics of aquatic plants.
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A dense grid of high- and very high resolution seismic data, together with piston cores and borehole data providing time constraints, enables us to reconstruct the history of the Bourcart canyon head in the western Mediterranean Sea during the last glacial/interglacial cycle. The canyon fill is composed of confined channel–levee systems fed by a series of successively active shelf fluvial systems, originating from the west and north. Most of the preserved infill corresponds to the interval between Marine Isotope Stage (MIS) 3 and the early deglacial (19 cal ka BP). Its deposition was strongly controlled by a relative sea level that impacted the direct fluvial/canyon connection. During a period of around 100 kyr between MIS 6 and MIS 2, the canyon “prograded” by about 3 km. More precisely, several parasequences can be identified within the canyon fill. They correspond to forced-regressed parasequences (linked to punctuated sea-level falls) topped by a progradational-aggradational parasequence (linked to a hypothetical 19-ka meltwater pulse (MWP)). The bounding surfaces between forced-regressed parasequences are condensed intervals formed during intervals of relative sediment starvation due to flooding episodes. The meandering pattern of the axial incision visible within the canyon head, which can be traced landward up to the Agly paleo-river, is interpreted as the result of hyperpycnal flows initiated in the river mouth in a context of increased rainfall and mountain glacier flushing during the early deglacial.
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Based upon qualitative parameters experiments, this study aims to investigate how the elements of the environment, where the coffee is produced, contribute to the final quality of the product. For the analyses, it was used approximately one kilogram of coffee cherry samples collected in 14municipalities previously chosen on the East side of the Minas Gerais State, Brazil. The coffee cherry samples were collected and analyzed for each of the two varieties in four levels of altitude for each exposure side of the mountain in relation to the Sun. The quality of the coffee was evaluated through the analysis of its physical characteristics and sensory analysis, popularly known as "Test of drink or Cupping" carried out by three tasters that belonging to the group of Q -Graders, according to the rules of national and international competitions of the Brazilian Association of Special Coffees (BSCA). Were performed analysis by means descriptive statistics, analysis of variance and multivariate analysis, all of them aiming to study the individual sensor y characteristics of quality of the coffee beverage from the ?Matas de Minas? region. Path coefficient analysis also was carried out for the partition of the phenotypic correlation coefficients into measures of direct and indirect effects, in order to determine the individual sensory characteristics that playeda major role in the beverage final score. The results demonstrat e that it is not possible to concl usively establish the differences among coffees evaluated with basis on varieties and environmental factors previously cited. It can be concluded that it is not recommended to associate the quality of coffee only to a specific factor whether from the environment or being it a specific of the culture of coffee. However, the cafes that were evaluated had intrinsic quality, which were derived from the specific characteristics of the ?Matas de Minas? region where they were grown.
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Bone marrow is organized in specialized microenvironments known as 'marrow niches'. These are important for the maintenance of stem cells and their hematopoietic progenitors whose homeostasis also depends on other cell types present in the tissue. Extrinsic factors, such as infection and inflammatory states, may affect this system by causing cytokine dysregulation (imbalance in cytokine production) and changes in cell proliferation and self-renewal rates, and may also induce changes in the metabolism and cell cycle. Known to relate to chronic inflammation, obesity is responsible for systemic changes that are best studied in the cardiovascular system. Little is known regarding the changes in the hematopoietic system induced by the inflammatory state carried by obesity or the cell and molecular mechanisms involved. The understanding of the biological behavior of hematopoietic stem cells under obesity-induced chronic inflammation could help elucidate the pathophysiological mechanisms involved in other inflammatory processes, such as neoplastic diseases and bone marrow failure syndromes.
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Among the various ways of adopting the biographical approach, we used the curriculum vitaes (CVs) of Brazilian researchers who work as social scientists in health as our research material. These CVs are part of the Lattes Platform of CNPq - the National Council for Scientific and Technological Development, which includes Research and Institutional Directories. We analyzed 238 CVs for this study. The CVs contain, among other things, the following information: professional qualifications, activities and projects, academic production, participation in panels for the evaluation of theses and dissertations, research centers and laboratories and a summarized autobiography. In this work there is a brief review of the importance of autobiography for the social sciences, emphasizing the CV as a form of autobiographical practice. We highlight some results, such as it being a group consisting predominantly of women, graduates in social sciences, anthropology, sociology or political science, with postgraduate degrees. The highest concentration of social scientists is located in Brazil's southern and southeastern regions. In some institutions the main activities of social scientists are as teachers and researchers with great thematic diversity in research.
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The introduction of spraying procedures to fabricate layer-by-layer (LbL) films has brought new possibilities for the control of molecular architectures and for making the LbL technique compliant with industrial processes. In this study we show that significantly distinct architectures are produced for dipping and spray-LbL films of the same components, which included DODAB/DPPG vesicles. The films differed notably in their thickness and stratified nature. The electrical response of the two types of films to aqueous solutions containing erythrosin was also different. With multidimensional projections we showed that the impedance for the DODAB/DPPG spray-LbL film is more sensitive to changes in concentration, being therefore more promising as sensing units. Furthermore, with surface-enhanced Raman scattering (SERS) we could ascribe the high sensitivity of the LbL films to adsorption of erythrosin.
Resumo:
Cryosurgery is an efficient therapeutic technique used to treat benign and malignant cutaneous diseases. The primary active mechanism of cryosurgery is related to vascular effects on treated tissue. After a cryosurgical procedure, exuberant granulation tissue is formed at the injection site, probably as a result of angiogenic stimulation of the cryogen and inflammatory response, particularly in endothelial cells. To evaluate the angiogenic effects of freezing, as part of the phenomenon of healing rat skin subjected to previous injury. Two incisions were made in each of the twenty rats, which were divided randomly into two groups of ten. After 3 days, cryosurgery with liquid nitrogen was performed in one of incisions. The rats' samples were then collected, cut and stained to conduct histopathological examination, to assess the local angiogenesis in differing moments and situations. It was possible to demonstrate that cryosurgery, in spite of promoting cell death and accentuated local inflammation soon after its application, induces quicker cell proliferation in the affected tissue and maintenance of this rate in a second phase, than in tissue healing without this procedure. These findings, together with the knowledge that there is a direct relationship between mononuclear cells and neovascularization (the development of a rich system of new vessels in injury caused by cold), suggest that cryosurgery possesses angiogenic stimulus, even though complete healing takes longer to occur. The significance level for statistical tests was 5% (p<0,05).
Resumo:
This study investigated the effect of simulated microwave disinfection (SMD) on the linear dimensional changes, hardness and impact strength of acrylic resins under different polymerization cycles. Metal dies with referential points were embedded in flasks with dental stone. Samples of Classico and Vipi acrylic resins were made following the manufacturers' recommendations. The assessed polymerization cycles were: A-- water bath at 74ºC for 9 h; B-- water bath at 74ºC for 8 h and temperature increased to 100ºC for 1 h; C-- water bath at 74ºC for 2 h and temperature increased to 100ºC for 1 h;; and D-- water bath at 120ºC and pressure of 60 pounds. Linear dimensional distances in length and width were measured after SMD and water storage at 37ºC for 7 and 30 days using an optical microscope. SMD was carried out with the samples immersed in 150 mL of water in an oven (650 W for 3 min). A load of 25 gf for 10 sec was used in the hardness test. Charpy impact test was performed with 40 kpcm. Data were submitted to ANOVA and Tukey's test (5%). The Classico resin was dimensionally steady in length in the A and D cycles for all periods, while the Vipi resin was steady in the A, B and C cycles for all periods. The Classico resin was dimensionally steady in width in the C and D cycles for all periods, and the Vipi resin was steady in all cycles and periods. The hardness values for Classico resin were steady in all cycles and periods, while the Vipi resin was steady only in the C cycle for all periods. Impact strength values for Classico resin were steady in the A, C and D cycles for all periods, while Vipi resin was steady in all cycles and periods. SMD promoted different effects on the linear dimensional changes, hardness and impact strength of acrylic resins submitted to different polymerization cycles when after SMD and water storage were considered.
Resumo:
Most epidemiological studies concerning differentiated thyroid cancers (DTC) indicate an increasing incidence over the last two decades. This increase might be partially explained by the better access to health services worldwide, but clinicopathological analyses do not fully support this hypothesis, indicating that there are carcinogenetic factors behind this noticeable increasing incidence. Although we have undoubtedly understood the biology and molecular pathways underlying thyroid carcinogenesis in a better way, we have made very little progresses in identifying a risk profile for DTC, and our knowledge of risk factors is very similar to what we knew 30-40 years ago. In addition to ionizing radiation exposure, the most documented and established risk factor for DTC, we also investigated the role of other factors, including eating habits, tobacco smoking, living in a volcanic area, xenobiotics, and viruses, which could be involved in thyroid carcinogenesis, thus, contributing to the increase in DTC incidence rates observed.
Resumo:
The maintenance of glucose homeostasis is complex and involves, besides the secretion and action of insulin and glucagon, a hormonal and neural mechanism, regulating the rate of gastric emptying. This mechanism depends on extrinsic and intrinsic factors. Glucagon-like peptide-1 secretion regulates the speed of gastric emptying, contributing to the control of postprandial glycemia. The pharmacodynamic characteristics of various agents of this class can explain the effects more relevant in fasting or postprandial glucose, and can thus guide the individualized treatment, according to the clinical and pathophysiological features of each patient.