2,693 research outputs found
Influence of the Multidecadal Atlantic Meridional Overturning Circulation Variability on European Climate
The influence of the natural multidecadal variability of the Atlantic meridional overturning circulation (MOC) on European climate is investigated using a simulation with the coupled atmosphere–ocean general circulation model ECHAM5/Max Planck Institute Ocean Model (MPI-OM). The results show that Atlantic MOC fluctuations, which go along with changes in the northward heat transport, in turn affect European climate. Additionally, ensemble predictability experiments with ECHAM5/MPI-OM show that the probability density functions of surface air temperatures in the North Atlantic/European region are affected by the multidecadal variability of the large-scale oceanic circulation. Thus, some useful decadal predictability may exist in the Atlantic/European sector
Laboratory Investigation of Skid Resistance for Steel Slag Utilization as Chip Seal
Slag as waste material of steel-making process has similar characteristics with aggregate that has been widely used in pavement construction. The use of slag as chip seal aggregate to provide skid resistance needs to be analyzed. In this laboratory study, the chip seal samples are made using steel slag and natural aggregate. The bonding materials used are asphalt and epoxy resin. Skid resistance tests for all chip seal samples and also hot rolled sheet pavement without chip seal application are performed using the Portable British Pendulum Tester. The results show the variations of chip seal aggregate weight are inconsistent. The natural aggregate used as chip seal material could produce high skid resistance value of 10.3% higher than that using steel slag. Also the skid resistance of chip seal with the ALD 3 mm are not significantly different with that of ALD 6 mm. Similar results occur on the skid resistance of chip seals using epoxy resin and asphalt
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A tale of one city: intra-institutional variations in migrating VLE platform
City University London committed in 2009 to make Moodle the Virtual Learning Environment (VLE) at the core of a new Strategic Learning Environment (SLE) comprised of VLE, externally facing website and related systems such as video streaming and virtual classrooms. Previously, the WebCT VLE had been separate from most of the other systems at the institution with very limited connections to other tools. Each of the schools within the institution was able to pursue their own strategy and timeframe for the migration and embedding of Moodle within their subject areas, within an absolute limit of 2 years. This paper outlines the approaches taken by the various schools, highlighting similarities and differences, and draws out common aspects from the project to make recommendations for institutions seeking to undertake similar migrations
On multidecadal and quasi-decadal North Atlantic variability
Observed sea surface temperatures (SSTs) in the North Atlantic from 1958 through 2000, as well as data from an ocean model simulation driven with the atmospheric variability observed during the same period, are examined using multichannel singular spectrum analysis. The two leading oscillatory modes are associated with a multidecadal and a quasi-decadal period. The former is connected to a basinwide uniform SST pattern and changes in the deep North Atlantic meridional overturning circulation. The quasi-decadal mode involves a tripolar SST anomaly pattern forced by atmospheric variability with a spatial structure resembling that of the North Atlantic Oscillation (NAO). The upper ocean’s dynamical response to this NAO variability provides an instantaneous positive feedback to the SST pattern, while a delayed negative feedback is due to shallow overturning circulation anomalies
New Genetic Insights from Autoimmune Thyroid Disease
The autoimmune thyroid diseases (AITDs) (Graves' disease and Hashimoto's thyroiditis) are complex genetic diseases which most likely have more than 20 genes contributing to the clinical phenotypes. To date, the genes known to be contributing fall into two categories: immune regulatory genes (including HLA, CTLA4, PTPN22, CD40, CD25, and FCRL3) and thyroid-specific genes (TG and TSHR). However, none of these genes contribute more than a 4-fold increase in risk of developing one of these diseases, and none of the polymorphisms discovered is essential for disease development. Hence, it appears that a variety of different gene interactions can combine to cause the same clinical disease pattern, but the contributing genes may differ from patient to patient and from population to population. Furthermore, this possible mechanism leaves open the powerful influence of the environment and epigenetic modifications of gene expression. For the clinician, this means that genetic profiling of such patients is unlikely to be fruitful in the near future
Validating the mediating effect of negotiation style between problem-solving strategies and communication style on marital satisfaction among Nigerian
This study validating the mediating effect of negotiation style between problem solving strategies and Communication style on Marital Satisfaction among Nigerian. To achieve the purpose a cross-sectional survey design was adopted with a sample of 385 married couples in Kwara state Nigeria. The instruments used tagged 'Problem-Solving Strategies, Communication and Negotiation styles on Marital Satisfaction Scales' contained 80 items spread among the 16 sub-constructs, 4 Likert's type was adopted throughout the scale. The data collected were entered into Microsoft Excel 2016 and SPSS 20 for data cleaning and were filtered to the SmartPLS 3. The data was check for normality using two indicators of Skewness and Kurtosis. The data analysis was conducted using Partial least square structural equation modeling approaches with SmartPLS 3 software. The measurement construct was evaluated by items loading, composite reliability (CR) and average variance extracted (AVE). The results revealed that the measurement construct assessed in this study showed acceptability with validity and reliability test results presented in the preceding sections. The indicator reliability, convergent validity examined through the factor loadings. Thus with the effect of all the measurement requirements, it can be concluded that the mediating effect of negotiation style between Problem-Solving Strategies and Communication style on Marital Satisfaction can be used to the resolved marital problem among the couples as an alternative option for marital counselor ministry of social welfare and the religious leaders
Hypoxia and hyperglycaemia determine why some endometrial tumours fail to respond to metformin
High expression of Ki67, a proliferation marker, is associated with reduced endometrial cancer-specific survival. Pre-surgical metformin reduces tumour Ki-67 expression in some women with endometrial cancer. Metformin's anti-cancer activity may relate to effects on cellular energy metabolism. Since tumour hypoxia and glucose availability are major cellular redox determinants, we evaluated their role in endometrial cancer response to metformin. Endometrial cancer biopsies from women treated with pre-surgical metformin were tested for the hypoxia markers, HIF-1α and CA-9. Endometrial cancer cell lines were treated with metformin in variable glucose concentrations in normoxia or hypoxia and cell viability, mitochondrial biogenesis, function and energy metabolism were assessed. In women treated with metformin (n = 28), Ki-67 response was lower in hypoxic tumours. Metformin showed minimal cytostatic effects towards Ishikawa and HEC1A cells in conventional medium (25 mM glucose). In low glucose (5.5 mM), a dose-dependent cytostatic effect was observed in normoxia but attenuated in hypoxia. Tumours treated with metformin showed increased mitochondrial mass (n = 25), while in cultured cells metformin decreased mitochondrial function. Metformin targets mitochondrial respiration, however, in hypoxic, high glucose conditions, there was a switch to glycolytic metabolism and decreased metformin response. Understanding the metabolic adaptations of endometrial tumours may identify patients likely to derive clinical benefit from metformin
Progresses in multi-materials billet manufacturing out of metal scraps through friction stir consolidation
The evolution of Friction Stir Consolidation (FSC) from recycling towards upcycling
technique proved to be one of the excellent solid-state methods for manufacturing functionally
graded billets. Multi-material Functional Graded Materials (FGMs) represent a novel class of
materials characterized by a gradual change in properties and functions which can be tailored to
enhance components performance. Manufacturing techniques play a critical role in achieving the
designed compositional and microstructural distribution. Specifically, FSC allows the
manufacturing of FGM billets out of metallic chips; the mixing of different metallic chips offers
mutually exclusive mechanical properties like high hardness and good ductility in a single FSC
billet with excellent formability. The present research further explores some challenges while
combining dissimilar aluminum alloys chips in different percentages and spatial order, especially
in the radial direction. The mechanical and metallurgical properties were assessed through the
Vickers hardness measurements and microstructure analysis. The results revealed that new
strategies are needed for a better exploitation of FSC as a solid-state method for fabrication of
Functionally Graded Materia
GREEN SYNTHESIS OF PLANT-MEDIATED METAL NANOPARTICLES: THE ROLE OF POLYPHENOLS
The use of metal nanoparticles (MNPs) in various fields is increasing day-by-day leading to a genuine concern about the issues related to their environmental and biological safety. The major approaches for the synthesis of NPs include physical and chemical methods which are expensive and hazardous to health in addition to being toxic to the environment. This review highlights the potential of plant extracts to carry out the synthesis of MNPs with a special emphasis on the role of flavonoids in nanosynthesis. This green and clean approach have been actively utilized in recent years as an alternative to conventional hazardous approaches. It has proved as cost-effective, non-toxic, less time and labor consuming, efficient, and eco-friendly method for the synthesis of MNPs with specific biological actions. This review also focuses on the role of polyphenols, including the flavonoids as bioreductants of metal salts for the synthesis of NPs along with their biomedical applications. Various examples of the MNPs, along with their biological actions, have also been summarized
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