938 research outputs found
Experimental Investigation on the Behavior of Artificial Magnetic Cilia
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In the present work, the flow fields induced by the movement of artificial cilia under the effect of
a magnetic field are investigated. In order to obtain almost steady conditions, the set-up consists of fixed cilia
which oscillate under the action of a rotating magnetic field. The aim of the work is to determine under
which geometrical configurations a net flow rate or a global mixing is obtained. The results show that cilia
mounted in the direction of rotation allow net fluid flow, whereas those in radial position have larger
turbulent kinetic energy. Thus, the former could be used as micro-pump, whereas the latter as micro-mixer
The heat stress for workers employed in a dairy farm
The Italian dairy production is characterized by high heterogeneity. The typology quantitatively more important (80% of national production) is represented by cow’s milk cheeses (Grana Padano cheese, string cheese, Parmesan cheese, etc.), while the cheese from buffalo’s milk (especially string cheese such as mozzarella) and cheese from sheep and goats represents respectively 4% and 8% of the national dairy production, and are linked to specific regional contexts. Some phases of the cycle of milk processing occur at certain temperatures that are not comfortable for the workers also in relation to possible problems due to thermal shock. The aim of this study was to evaluate the risk of heat stress on workers operating in a dairy for processing of buffalo milk. The research was conducted at a dairy farm located in the province of Viterbo, Italy, during the spring-summer period. To carry out the research were detected major climatic parameters (air temperature, relative humidity, mean radiant temperature, air velocity) and the main parameters of the individual operators (clothing thermal insulation and the energy expenditure required from the work done by employees). Subsequently, main indices of heat stress assessment provided by the main technical standards were calculated. In particular have been calculated predicted mean vote and predicted percentage of dissatisfied in moderate thermal environments (environments in which the objective, in the design and management phases, is to achieve the thermal comfort), provided by the UNI EN ISO 7730 and the wet bulb globe temperature in severe hot environments (environments in which you must protect the health of workers) required by UNI EN ISO 27243. The results show some phases of risk from heat stress especially during times of test in which the internal air temperature exceeds the threshold of 30°C and possible solutions to improve the safety of the operators
GALNT2 as a novel modulator of adipogenesis and adipocyte insulin signaling
Background/objectives: A better understanding of adipose tissue biology is crucial to tackle insulin resistance and eventually coronary heart disease and diabetes, leading causes of morbidity and mortality worldwide. GALNT2, a GalNAc-transferase, positively modulates insulin signaling in human liver cells by down-regulating ENPP1, an insulin signaling inhibitor. GALNT2 expression is increased in adipose tissue of obese as compared to that of non-obese individuals. Whether this association is secondary to a GALNT2-insulin sensitizing effect exerted also in adipocytes is unknown. We then investigated in mouse 3T3-L1 adipocytes the GALNT2 effect on adipogenesis, insulin signaling and expression levels of both Enpp1 and 72 adipogenesis-related genes. Methods: Stable over-expressing GALNT2 and GFP preadipocytes (T 0 ) were generated. Adipogenesis was induced with (R+) or without (R−) rosiglitazone and investigated after 15 days (T 15 ). Lipid accumulation (by Oil Red-O staining) and intracellular triglycerides (by fluorimetric assay) were measured. Lipid droplets (LD) measures were analyzed at confocal microscope. Gene expression was assessed by RT-PCR and insulin-induced insulin receptor (IR), IRS1, JNK and AKT phosphorylation by Western blot. Results: Lipid accumulation, triglycerides and LD measures progressively increased from T 0 to T 15 R- and furthermore to T 15 R+. Such increases were significantly higher in GALNT2 than in GFP cells so that, as compared to T 15 R+GFP, T 15 R- GALNT2 cells showed similar (intracellular lipid and triglycerides accumulation) or even higher (LD measures, p < 0.01) values. In GALNT2 preadipocytes, insulin-induced IR, IRS1 and AKT activation was higher than that in GFP cells. GALNT2 effect was totally abolished during adipocyte maturation and completely reversed at late stage maturation. Such GALNT2 effect trajectory was paralleled by coordinated changes in the expression of Enpp1 and adipocyte-maturation key genes. Conclusions: GALNT2 is a novel modulator of adipogenesis and related cellular phenotypes, thus becoming a potential target for tackling the obesity epidemics and its devastating sequelae
Land take and landscape loss: Effect of uncontrolled urbanization in Southern Italy
The present paper describes a research that, based on the evolutionary data of the urban settlement over a period of half a century, shows the changes undergone by the various landscape categories of Southern Italy. The regions involved are four (Campania, Basilicata, Puglia and Calabria) and share renowned urban, economic and social issues such as unauthorised development, low income per capita and organised crime. All this has produced profound transformations on some of the most important and rare Italian landscapes, such as coastal plains and coastal carbonate slabs. Uncontrolled urban sprawl has further provoked an environmental crisis and eco-friendly insularisation of the yet numerous and valuable protected areas of this geographical area, thus leading to a high density of buildings and infrastructures even in national parks, breaking European records in this respect. Through finalised indicators, the characteristics of the evolution occurred have been analytically highlighted, and by using the latest generation satellite data, it is shown how such phenomena have continued to take place with significant energy over the last few years. The result is a picture of environmental threats still very prominent in this southern extremity of the peninsula, above all towards those naturalistic qualities and landscapes that are the main attractions of an intense national and international tourism whose income, however, has not been conveyed in a correct and inclusive way to allow high-level socio-economic conditions of the resident population. Keywords: Urban growth, Land take, Landscape loss, Urban sprinkling, South Ital
Association of a homozygous GCK missense mutation with mild diabetes
Background: Homozygous inactivating GCK mutations have been repeatedly reported to cause severe hyperglycemia, presenting as permanent neonatal diabetes mellitus (PNDM). Conversely, only two cases of GCK homozygous mutations causing mild hyperglycemia have been so far described. We here report a novel GCK mutation (c.1116G>C, p.E372D), in a family with one homozygous member showing mild hyperglycemia. Methods: GCK mutational screening was carried out by Sanger sequencing. Computational analyses to investigate pathogenicity and molecular dynamics (MD) were performed for GCK-E372D and for previously described homozygous mutations associated with mild (n = 2) or severe (n = 1) hyperglycemia, used as references. Results: Of four mildly hyperglycemic family-members, three were heterozygous and one, diagnosed in the adulthood, was homozygous for GCK-E372D. Two nondiabetic family members carried no mutations. Fasting glucose (p = 0.016) and HbA1c (p = 0.035) correlated with the number of mutated alleles (0–2). In-silico predicted pathogenicity was not correlated with the four mutations’ severity. At MD, GCK-E372D conferred protein structure flexibility intermediate between mild and severe GCK mutations. Conclusions: We present the third case of homozygous GCK mutations associated with mild hyperglycemia, rather than PNDM. Our in-silico analyses support previous evidences suggesting that protein stability plays a role in determining clinical severity of GCK mutations
La extensión de la obligatoriedad educativa en la Provincia del Chaco. Análisis de la posibilidad de su efectivización
En América Latina, durante las últimas décadas se manifestó una importante expansión de los sistemas educativos nacionales, con especial énfasis en la modalidad de formación profesional. Este crecimiento requirió de un fuerte correlato financiero para atender los gastos demandados por el crecimiento de matrÃcula y la instauración de nuevas especialidades de formación. Sin embargo, Jallade (1988:7) advertÃa que el aumento del gasto público en educación planteaba algunos inconvenientes que remitÃan a la necesidad de establecer "la eficacia social y económica de esos gastos"
Innovación y calidad
En su génesis, el modelo de educación sistematizada que la sociedad demandaba para la satisfacción de las crecientes necesidades de la población estructuró un arquetipo conforme las limitadas capacidades de respuesta personal e institucional a los requerimientos más patentes que emergÃan del contexto social, económico y cultural; sin embargo, el contexto demandante cambió significativamente en los últimos decenio
A Raman study of diamond film growth on Co-cemented tungsten carbide
Phase purity and crystallinity of diamond films grown by hot filament chemical vapor deposition on ISO-grade K10 cemented carbide [94.2 weight percent (w/o) WC-5.8 w/o Co] were studied by Raman spectroscopy as a function of substrate temperature, gas phase composition, and substrate pretreatments. High-quality diamond films were grown using 0.5% CH4/H-2 in a rather narrow range of substrate temperatures (750 to 760 degrees C). In all the deposited coatings, the first-order Raman band of diamond is detected at 1337 cm. This fact indicates that a 2 GPa residual compressive stress is present in the diamond phase. The linewidth of the diamond Raman peak increases with deposition temperature. This effect has been ascribed to a higher density of defects in diamond crystallites. It has been observed that Co removal from the substrate surface by wet chemical etching before deposition is less effective than a careful selection of deposition parameters to reduce the codeposition of nondiamond carbon phases. This finding has been attributed to the fast diffusion of the binder from the bulk to the substrate surface, even for the etched substrates
The Semitransparent Photovoltaic Films for Mediterranean Greenhouse: A New Sustainable Technology
Mediterranean countries offer very favorable climatic conditions for growing plants in a protected environment: as a matter of fact, the high solar radiation allows the use of greenhouses with simple structures, covered with plastic film and without fixed installations for winter heating. They are called "Mediterranean greenhouses" and are totally different from those in Central and Northern Europe. In the photovoltaic greenhouses, the cover on the pitch facing south is usually replaced by very opaque panels. However, this solution compromises the possibility to grow plants in covered and protected environments since solar radiation availability is limited and strongly nonuniform. In order to overcome this problem, semitransparent photovoltaic materials can be used to let the solar energy, necessary for plant growth, pass into the green house. The aim of this research is to analyze the radiometric properties of innovative semitransparent flexible photovoltaic materials in order to evaluate their performances in comparison with materials commonly used in the coverage of the greenhouses. Particular attention is paid to the transmittance of these materials in the visible range and in the long wave infrared for the achievement of greenhouse effect
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