921 research outputs found
1.65 micrometers (H-band) surface photometry of galaxies. III: observations of 558 galaxies with the TIRGO 1.5m telescope
We present near-infrared H-band (1.65 micron) surface photometry of 558
galaxies in the Coma Supercluster and in the Virgo cluster. This data set,
obtained with the Arcetri NICMOS3 camera ARNICA mounted on the Gornergrat
Infrared Telescope, is aimed at complementing, with observations of mostly
early-type objects, our NIR survey of spiral galaxies in these regions,
presented in previous papers of this series. Magnitudes at the optical radius,
total magnitudes, isophotal radii and light concentration indices are derived.
We confirm the existence of a positive correlation between the near-infrared
concentration index and the galaxy H-band luminosity. (Tables 1 and 2 are only
available in electronic form upon request to [email protected])Comment: 12 pages, 6 figures. Accepted for publication in A&A
La tubercolosi ricorrente : recidiva o reinfezione esogena?
Recurrent tuberculosis (TB) is an issue that makes worldwide eradication of the disease difficult, especially in countries with a high incidence of TB. Recurrent TB may be due to relapse of the original episode or to an exogenous
reinfection caused by a different strain of Mycobacterium
tuberculosis.
We performed a meta-analysis of selected studies on recurrent TB from 2000 to 2013, adopting molecular genotyping to discriminate between exogenous reinfection and relapses, in order to specifically evaluate the role of HIV infection in the origin of recurrence. Comparison among the studies was limited by the population heterogeneity of the different studies in terms of epidemiology, health status, and diagnostic and therapeutic approach. However, exogenous reinfections are
more common in high-burden countries, where HIV infection plays a major role in increasing the risk of a new
infection. In contrast, this finding was not confirmed in low-burden countries.
Vice versa, globally recognized factors for TB relapse were low compliance to anti-tuberculous treatment,multidrug resistance and persistence of cavitations in the lung parenchyma. The role of other factors like social
conditions (immigration, homelessness, working conditions),co-morbidities (silicosis), and characteristics of
anti-TB treatment is still controversial
Population assessment without individual identification using camera-traps: a comparison of four methods
The use of camera traps to estimate population size when animals are not individually recognizable is gaining traction in the ecological literature, because of its applicability in population conservation and management. We estimated population size of synthetic animals with four camera trap sampling-based statistical models that do not rely on individual recognition. Using a realistic model of animal movement to generate synthetic data, we compared the random encounter model, the random encounter and staying time model, the association model and the time-to-event-model and we investigated the impact of violation of assumptions on the population size estimates. While under ideal conditions these models provide reliable population estimates, when synthetic animal movements were characterised by differences in speed (due to diverse behaviours such as locomotion, grazing and resting) none of the model provided both unbiased and precise density estimates. The random encounter model and the time-to-event-model provided pre- cise results but tended to overestimate population size, while the random encounter and staying time model was less precise and tended to underestimate population size. Lastly, the association model was unable to provide precise results. We found that each tested model was very sensitive to the method used to estimate the range of the field-of-view of camera traps. Density esti- mates from both random encounter model and time-to-event-model were also very sensitive to biases in the estimate of ani- mals’ speed. We provide guidelines on how to use these statistical models to get population size estimates that could be useful to wildlife managers and practitioners
From wheat sourdough to gluten-free sourdough: a conventional process for producing gluten-free bread
Gluten-free (GF) sourdough was prepared from wheat sourdough and analysed both in fresh (GFS) and dried forms (DGFS). The gluten content in each GF sourdough sample was <20mgkg(-1). The dough leavening capacity and the properties of the bread samples were investigated and compared to those of bread prepared using bakery yeast (Saccharomyces cerevisiae). Two commercial rice-based mixtures (different for the presence/absence of buckwheat flour) were used to prepare bread samples. In GFS, lactic acid bacteria (LAB) and yeasts were found in amounts corresponding to 10(8) and 10(7) CFUg(-1), respectively, whereas both LAB and yeasts were detected in lower amounts (about 10(6) CFUg(-1)) in DGFS. When used in bread-making, both GFS types produced significant dough acidification and exhibited good dough development during proofing, resulting in loaves with specific volume values between 3.00 and 4.12mLg(-1), values similar to those obtained for reference bread (3.05 divided by 4.15mLg(-1)). The use of GFS was effective in lowering the bread staling rate during storage for up to 7days
Environmental and surface hygienic quality of small dairies in mountain areas: suggestion to improve food safety
The present study investigates the quality of the environment and of the work surface in small family-run dairies to identify critical factors that are frequently neglected, despite their potentially decisive role in improving the hygiene standards of dairy processing.
The major problems of family-run dairies are related to the microbial contamination and the environmental conditions that are essential for quality cheesemaking. The production structures are not functional, and it is difficult to protect both the processing and the environment from contaminants.
Hygiene in both the environment and on the surface of the equipment is important to avoid microbial contamination, and if food-environment interactions are not monitored correctly, food safety can be at risk. Indeed, incorrect cleaning operations and poor hygiene habits by workers facilitate microbial transfer from the environment to the food, where microbes find suitable substrates and conditions to increase.
In accordance with HACCP rules, the quality of raw materials and the cleaning operations of the processing premises are important aspects to guarantee the safety and quality of the final product.
This paper studies the preliminary environmental quality with the aim of finding critical points for food safety
Innovation Technology to Empower Safety, Health and Welfare in Agriculture and Agro-food Systems
Abstract This survey investigates the quality of the environment and any work surface (floors, walls, worktops) in small family-run dairies to identify frequently neglected critical factors, despite their potentially decisive role in improving the hygiene standards of dairy processing. The major problems of small dairies are related to the microbial contamination and the environmental conditions that are essential for quality cheese-making. Hygiene both in the environment and on the work surfaces is important to avoid microbial contamination, and if food-environment interactions are not monitored correctly, food safety can be at risk. The choice of the sample fell upon family-run farms still characterized by craft work and traditional methods. In every dairy and in all processing premises, surveys were carried out to assess microbes and eumycetes role in air and work surface contamination. Air contamination was checked by means of a microbiological air sampler followed by colony count. The microbial surface contamination was determined by three different techniques (swab method, sponge method and bioluminescence method). In general air quality appeared to be good. A small number of microbiological health indicators, found just outside the entrance to the dairy, were due to cross-contamination coming from the cattle-shed. In some cases work equipment surfaces revealed unsatisfactory hygienic conditions due to ineffective cleaning operations. In this respect we underline that it would be useful to use boiling whey especially in dairies where running water is not available
Post-Depositional Biodegradation Processes of Pollutants on Glacier Surfaces
Glaciers are important fresh-water reservoirs for our planet. Although they are often
located at high elevations or in remote areas, glacial ecosystems are not pristine, as many pollutants
can undergo long-range atmospheric transport and be deposited on glacier surface, where they
can be stored for long periods of time, and then be released into the down-valley ecosystems.
Understanding the dynamics of these pollutants in glaciers is therefore important for assessing their
environmental fate. To this aim, it is important to study cryoconite holes, small ponds filled with
water and with a layer of sediment, the cryoconite, at the bottom, which occur on the surface of
most glaciers. Indeed, these environments are hotspots of biodiversity on glacier surface as they host
metabolically active bacterial communities that include generalist taxa able to degrade pollutants.
In this work, we aim to review the studies that have already investigated pollutant (e.g., chlorpyrifos
and polychlorinated-biphenyls (PCBs)) degradation in cryoconite holes and other supraglacial
environmental matrices. These studies have revealed that bacteria play a significant role in pollutant
degradation in these habitats and can be positively selected in contaminated environments. We will
also provide indication for future research in this field
Wheat germ stabilization by heat-treatment or sourdough fermentation: effects on dough rheology and bread properties
The aim of this work was to evaluate the effects of wheat germ - stabilized by toasting or by sourdough fermentation - on dough and bread properties. Doughs were produced by adding increasing amounts of each type of stabilized germ, starting with the current recommended level of 3 g/100 g up to 20 g/100 g. Sourdough fermentation ensured the presence of lactic acid bacteria (LAB) in amounts comparable to those found in conventional sourdough. The acidification induced by LAB inactivates lipase and lipoxygenase, as does the toasting process. These results account for the decrease in rancidity, as demonstrated by the low development of hexanal during storage. Fermentation significantly decreased the content of glutathione, responsible for the deterioration of the rheological characteristics and workability of dough containing high levels of germ. Dough enriched with fermented germ exhibited high stability during mixing and development. Positive effects (high specific volume and low firmness) associated with the use of germ stabilized by fermentation have been detected both in fresh bread and in samples stored up to 4 days in controlled conditions of humidity and temperature. Finally, the sensory consumers' test confirmed that the addition of fermented germ did not diminish the liking of the sample
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