2,594 research outputs found
Metallogenetic evolution of the Canadian Cordilleran Orogen
From Introduction: The Canadian Cordilleran Orogenic Belt forms part of the circum-Pacific orogenic zone. It underlies an area of about 1,54 million sq. kilometres, is over 2400 kilometres long and 800 kilometres wide. The region is characteristically mountainous, much of it glaciated and alpine, containing plateaux, trenches, valleys, and fjords. The mountains, in general, rise to elevations between 2100 m and 3600 m above sea level, although Mount Logan in the St. Elias Mountains attains an altitude of 6000 m. The Canadian Cordillera is divided into two dominant orogenic belts: the eastern Columbian Orogenic Belt comprising defonned miogeosynclinal rocks and the western Pacific Orogenic Belt comprising allochthonous eugeosynclinal rocks. The Cordillera is further subdivided into five longitudinal tectonic belts within which rocks are broadly similar in type, age, and history. These belts are, from east to west: the Rocky Mountain Belt, the Omineca Crystalline Belt, the Intermontane Belt, the Coast Plutonic Complex, and the Insular Belt (Wheeler et al., 1972a). The Canadian Cordillera is important in that it contains: one of the world's largest lead-zinc-silver mine, Sullivan; the second-largest molybdenum mine, Endako; one of the most important concentrations of porphyry copper deposits, Highland Valley; Canada's largest tungsten mines, Cantung and Mactung; and Canada's second-largest silver district, Keno Hill (Sutherland Brown et a1., 1971). In addition, it contains several large massive sulphide and lead-zinc deposits
Perceptions of the role played by aquaculture and the services it provides for territories: complementarity of survey types
Open Access JournalThis article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such services in order to be able to prioritize them with respect to social well-being. This identification phase is seldom discussed. It requires that survey questionnaires be designed so as to improve understanding of these perceptions. The surveys undertaken combined both open questions where the interviewees expressed their perceptions spontaneously and closed questions where they were invited to rank a pre-established list of the relevant services. These surveys involved 133 fish farmers and 93 stakeholders. The results show that perceptions differ by question type, and confirm the significance of the questionnaire design and the importance of combining several kinds of approach
Fast DNA translocation through a solid-state nanopore
We report translocation experiments on double-strand DNA through a silicon
oxide nanopore. Samples containing DNA fragments with seven different lengths
between 2000 to 96000 basepairs have been electrophoretically driven through a
10 nm pore. We find a power-law scaling of the translocation time versus
length, with an exponent of 1.26 0.07. This behavior is qualitatively
different from the linear behavior observed in similar experiments performed
with protein pores. We address the observed nonlinear scaling in a theoretical
model that describes experiments where hydrodynamic drag on the section of the
polymer outside the pore is the dominant force counteracting the driving. We
show that this is the case in our experiments and derive a power-law scaling
with an exponent of 1.18, in excellent agreement with our data.Comment: 5 pages, 2 figures. Submitted to PR
Highly skewed T-cell receptor V-beta chain repertoire in the bone marrow is associated with response to immunosuppressive drug therapy in children with very severe aplastic anemia
One of the major obstacles of immunosuppressive therapy (IST) in children with severe aplastic anemia (SAA) comes from the often months-long unpredictability of bone-marrow (BM) recovery. In this prospective study in children with newly diagnosed very severe AA (n=10), who were enrolled in the therapy study SAA-BFM 94, we found a dramatically reduced diversity of both CD4+ and CD8+ BM cells, as scored by comprehensive V-beta chain T-cell receptor (TCR) analysis. Strongly skewed TCR V-beta pattern was highly predictive for good or at least partial treatment response (n=6, CD8+ complexity scoring median 35.5, range 24â73). In contrast, IST in patients with rather moderate reduction of TCR V-beta diversity (n=4, CD8+ complexity scoring median 109.5, range 82â124) always failed (P=0.0095). If confirmed in a larger series of patients, TCR V-beta repertoire in BM may help to assign children with SAA up-front either to IST or to allogeneic stem-cell transplantation
The Determinant Factors in Managing Dengue Hemorrhagic Fever During the Covid-19 Pandemic: A Literature Review
During the COVID-19 Pandemic, differentiating tropical infectious diseases and COVID-19 can be challenging due to overlapping clinical presentations. Fever and nonspecific symptoms in early COVID-19 may be challenging to distinguish from dengue hemorrhagic fever (DHF) and malaria because respiratory signs may be absent or manifest later in the disease course. This literature review analyzes the determinant factors in managing DHF during the COVID-19 Pandemic. This paper was a systematic literature review of national and international journals in the Google Scholar and PubMed databases from 2019 to 2022. We used the PICOS framework to find articles. The Indonesian and English keywords were the speed of health service, dengue hemorrhagic fever, and COVID-19. There were two included studies in this systematic review. The results showed that during the Covid-19 Pandemic and the dengue epidemic, a triage strategy was crucial to detect Covid-19 that could potentially be misdiagnosed as DHF. In addition, the first delay in seeking care treatment for dengue infection was due to financial constraints and previous dengue infection. Moreover, the second delay was because of the availability of transportation, traffic density, and residency location. Furthermore, the third delay was because of the hospital's capacity. Thus, the determinant factors of managing Dengue Hemorrhagic Fever during the COVID-19 Pandemic were the similarity of the signs and symptoms of dengue fever with Covid-19, financial aspects, transportation factors, the hospital distance, and hospital capacity
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Decoupling of As and Fe release to Bangladesh groundwater under reducing conditions. Part I: Evidence from sediment profiles
This study reexamines the notion that extensive As mobilization in anoxic groundwater of Bangladesh is intimately linked to the dissolution of Fe oxyhydroxides on the basis of analyses performed on a suite of freshly collected samples of aquifer material. Detailed sediment profiles extending to 40 to 70 m depth below the surface were obtained at six sites where local groundwater As concentrations were known to span a wide range. The sediment properties that were measured include (1) the proportion of Fe(II) in the Fe fraction leached in hot 1.2 N HCl, (2) diffuse spectral reflectance, and (3) magnetic susceptibility. In parallel with local concentrations of dissolved As ranging from <5 to 600 ÎŒg/L, Fe(II)/Fe ratios in shallow (gray) Holocene sands tended to gradually increase with depth from values of 0.3 to 0.5 to up to 0.9. In deeper (orange) aquifers of presumed Pleistocene age that were separated from shallow sands by a clay layer and contained <5 ÎŒg/L dissolved As, leachable Fe(II)/Fe ratios averaged âŒ0.2. There was no consistent relation between sediment Fe(II)/Fe and dissolved Fe concentrations in groundwater in nearby wells. The reflectance measurements indicate a systematic linear relation (R2 of 0.66; n = 151) between the first derivative transform of the reflectance at 520 nm and Fe(II)/Fe. The magnetic susceptibility of the shallow aquifer sands ranged from 200 to 3600 (x 10â9 m3/kg SI) and was linearly related (R2 of 0.75; n = 29) to the concentrations of minerals that could be magnetically separated (0.03 to 0.79% dry weight). No systematic depth trends in magnetic susceptibility were observed within the shallow sands, although the susceptibility of deeper low-As aquifers was low (up to âŒ200 Ă 10â9 m3/kg SI). This set of observations, complemented by incubation results described in a companion paper by van Geen et al. (this volume), suggests that the release of As is linked to the transformation of predominantly Fe (III) oxyhydroxide coatings on sand particles to Fe(II) or mixed Fe(II/III) solid phases with a flatter reflectance spectrum such as siderite, vivianite, or magnetite, without necessarily resulting in the release of Fe to groundwater. The very low As/Fe ratio of magnetically separated minerals compared to the As/Fe of bulk acid leachate (2 vs. 40 10â6, respectively) suggests that such a transformation could be accompanied by a significant redistribution of As to a mobilizable phase on the surface of aquifer particles
Long-term, prolonged-release tacrolimus-based immunosuppression in de novo kidney transplant recipients: 5-year prospective follow-up of the ADHERE study patients.
The objectives of this study were to assess long-term graft survival, patient survival, renal function, and acute rejections in de novo kidney transplant recipients, treated with once-daily prolonged-release tacrolimus-based therapy. The study was a 5-year non-interventional prospective follow-up of patients from the ADHERE study, a Phase IV 12-month open-label assessment of patients randomized to receive prolonged-release tacrolimus in combination with mycophenolate mofetil (MMF) (Arm 1) or sirolimus (Arm 2). From 838 patients in the randomized study, 587 were included in the long-term follow-up, of whom 510 completed the study at year 5. At 1 year post-transplant, graft and patient survival rates were 93.0% and 97.8%, respectively, and at 5 years were 84.0% and 90.8%, respectively. Cox proportional hazards analysis showed no association between graft loss, initial randomized treatment arm, donor age, donor type, or sex. The 5-year acute rejection-free survival rate was 77.4%, and biopsy-confirmed acute rejection-free survival rate was 86.0%. Renal function remained stable over the follow-up period: mean ± SD eGFR 4-variable modification diet in renal disease formula (MDRD4) was 52.3 ± 21.6 ml/min/1.73 m2 at 6 months and 52.5 ± 23.0 ml/min/1.73 m2 at 5 years post-transplant. These findings support the role of long-term once-daily prolonged-release tacrolimus-based immunosuppression, in combination with sirolimus or MMF, for renal transplant recipients in routine clinical practice. ispartof: TRANSPLANT INTERNATIONAL vol:33 issue:2 pages:161-173 ispartof: location:England status: publishe
Estimation of annual average daily traffic with optimal adjustment factors
This study aimed to estimate the annual average daily traffic in inter-urban networks determining the best correlation (affinity) between the short period traffic counts and permanent traffic counters. A bi-level optimisation problem is proposed in which an agent in an upper level prefixes the affinities between short period traffic counts and permanent traffic counters stations and looks to minimise the annual average daily traffic calculation error while, in a lower level, an originâdestination (OâD) trip matrix estimation problem from traffic counts is solved. The proposed model is tested over the well-known Sioux-Falls network and applied to a real case of Cantabria (Spain) regional road network. The importance of determining appropriate affinity and the effect of localisation of permanent traffic counters stations are discussed
Data Mining for Action Recognition
© Springer International Publishing Switzerland 2015. In recent years, dense trajectories have shown to be an efficient representation for action recognition and have achieved state-of-the art results on a variety of increasingly difficult datasets. However, while the features have greatly improved the recognition scores, the training process and machine learning used hasnât in general deviated from the object recognition based SVM approach. This is despite the increase in quantity and complexity of the features used. This paper improves the performance of action recognition through two data mining techniques, APriori association rule mining and Contrast Set Mining. These techniques are ideally suited to action recognition and in particular, dense trajectory features as they can utilise the large amounts of data, to identify far shorter discriminative subsets of features called rules. Experimental results on one of the most challenging datasets, Hollywood2 outperforms the current state-of-the-art
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