584 research outputs found
State of the science regarding RF dosimetry, measurement and certification
Journal ArticleCellular telephones and wireless personal communication systems (PCS) are being introduced into society at a very rapid rate. Whereas the present-day cellular telephones in the United States operate at midband transmission frequencies of about 835 MHz (about 900 MHz in Europe), higher frequencies on the order of 1900 MHz (1800 MHz in Europe) are to be used for the PCS systems, including mobile telephones, wireless local area networks, pagers, personal health monitoring systems, global positioning systems, etc. This has resulted in public concern about the health hazards of radiofrequency (RF) electromagnetic fields that are emitted by these devices. To allay public concerns, the Federal Communications Commission (FCC) in the United States has decided to require compliance with the ANSI/IEEE RF safety guidelines (American National Standards Institute/Institute of Electrical and Electronics Engineers [ANSI/IEEE], 1992) for uncontrolled environments for all personal wireless devices that use more than 100 mW of time-averaged input power to the antenna
Nonlinear physics of the ionosphere and LOIS/LOFAR
The ionosphere is the only large-scale plasma laboratory without walls that
we have direct access to. From results obtained in systematic, repeatable
experiments in this natural laboratory, where we can vary the stimulus and
observe its response in a controlled, repeatable manner, we can draw
conclusions on similar physical processes occurring naturally in the Earth's
plasma environment as well as in parts of the plasma universe that are not
easily accessible to direct probing.
Of particular interest is electromagnetic turbulence excited in the
ionosphere by beams of particles (photons, electrons) and its manifestation in
terms of secondary radiation (electrostatic and electromagnetic waves),
structure formation (solitons, cavitons, alfveons, striations), and the
associated exchange of energy, linear momentum, and angular momentum.
We present a new diagnostic technique, based on vector radio allowing the
utilization of EM angular momentum (vorticity), to study plasma turbulence
remotely.Comment: Six pages, two figures. To appear in Plasma Physics and Controlled
Fusio
A case of bone lesion in a patient with relapsed chronic lymphocytic leukemia and review of the literature
Skeletal involvement in CLL is very rare. We present a case of ileum bone lesion during in a patient receiving 5th line of therapy. Despite radiotherapy and salvage therapies, subsequent bone lesions led to a fatal outcome. Further studies on the mechanism by which bone disease develops are currently needed
Can the development and autolysis of lactic acid bacteria influence the cheese volatile fraction? The case of Grana Padano
In this study, the relationship between the dynamics of the growth and lysis of lactic acid bacteria in Grana
Padano cheese and the formation of the volatile flavor compounds during cheese ripening was investigated.
The microbial dynamics of Grana Padano cheeses thatwere produced in two different dairies were followed during
ripening. The total and cultivable lactic microflora, community composition as determined by length heterogeneity-
PCR (LH-PCR), and extent of bacterial lysis using an intracellular enzymatic activity assaywere compared
among cheeses after 2, 6 and 13 months of ripening in two dairies.
The evolution of whole and lysed microbiota was different between the two dairies. In dairy 2, the number of
total cells was higher than that in dairy 1 in all samples, and the number of cells that lysed during ripening
was lower. In addition, at the beginning of ripening (2 months), the community structure of the cheese from
dairy 2 was more complex and was composed of starter lactic acid bacteria (Lactobacillus helveticus and Lactobacillus
delbrueckii) and NSLAB, possibly arising fromraw milk, including Lactobacillus rhamnosus/Lactobacillus casei
and Pediococcus acidilactici. On the other hand, the cheese from dairy 1 that ripened for 2 months was mainly
composed of the SLAB L. helveticus and L. delbrueckii. An evaluation of the free-DNA fraction through LH-PCR identified
those species that had a high degree of lysis. Data on the dynamics of bacterial growth and lysis were evaluated
with respect to the volatile profile and the organic acid content of the two cheeses after 13 months of
ripening, producing very different results. Cheese from dairy 1 showed a higher content of free fatty acids, particularly
those deriving from milk fat lipolysis, benzaldehyde and organic acids, such as pGlu and citric. In contrast,
cheese from dairy 2 had a greater amount of ketones, alcohols, hydrocarbons, acetic acid and propionic
acid. Based on these results, we can conclude that in the first cheese, the intracellular enzymes thatwere released
fromlysiswere mainly involved in aromaformation,whereas in the second cheese, the greater complexity of volatile
compounds may be associated with its more complex microbial composition caused from SLAB lysis and
NSLAB (mainly L. rhamnosus/L. casei) growth during ripening
Valorization of orange peels exploiting fungal solid-state and lacto-fermentation
BackgroundOrange peels can serve as a cost-effective raw material for the production of lactic acid. Indeed, given their high concentration of carbohydrates and low content of lignin, they represent an important source of fermentable sugars, recoverable after a hydrolytic step. ResultsIn the present article, the fermented solid, obtained after 5 days of Aspergillus awamori growth, was used as the only source of enzymes, mainly composed of xylanase (40.6 IU g(-1) of dried washed orange peels) and exo-polygalacturonase (16.3 IU g(-1) of dried washed orange peels) activities. After the hydrolysis, the highest concentration of reducing sugars (24.4 g L-1) was achieved with 20% fermented and 80% non-fermented orange peels. The hydrolysate was fermented with three lactic acid bacteria strains (Lacticaseibacillus casei 2246 and 2240 and Lacticaseibacillus rhamnosus 1019) which demonstrated good growth ability. The yeast extract supplementation increased the lactic acid production rate and yield. Overall, L. casei 2246 produced the highest concentration of lactic acid in mono-culture. ConclusionTo the best of our knowledge this is the first study exploiting orange peels as low-cost raw material for the production of lactic acid avoiding the employment of commercial enzymes. The enzymes necessary for the hydrolyses were directly produced during A. awamori fermentation and the reducing sugars obtained were fermented for lactic acid production. Despite this preliminary work carried out to study the feasibility of this approach, the concentrations of reducing sugars and lactic acid produced were encouraging, leaving open the possibility of other studies for the optimization of the strategy proposed here. (c) 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Bacterial composition, genotoxicity, and cytotoxicity of fecal samples from individuals consuming omnivorous or vegetarian diets
This study analyzes the composition of viable fecal bacteria and gut toxicology biomarkers of 29 healthy volunteers, who followed omnivorous, lacto-ovo-vegetarian, or vegan diets. In particular, the research was focused on the prevalence of some representative viable bacteria from the four dominant phyla (Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria) commonly present in human feces, in order to evaluate the relationship between microorganisms selected by the habitual dietary patterns and the potential risk due to fecal water (FW) genotoxicity and cytotoxicity, considered as biomarkers for cancer risk and protective food activity. The relative differences of viable bacteria among dietary groups were generally not statistically significant. However, compared to omnivores, lacto-ovo-vegetarians showed low levels of total anaerobes. Otherwise, vegans showed total anaerobes counts similar to those of omnivores, but with lower number of bifidobacteria and the highest levels of bacteria from the Bacteroides-Prevotella genera. FW genotoxicity of lacto-ovo-vegetarians resulted significantly lower either in relation to that of omnivores and vegans. Lacto-ovo-vegetarians also showed the lowest levels of cytotoxicity, while the highest were found for vegans. These results highlighted that lacto-ovo-vegetarian diet was particularly effective in a favorable modulation of microbial activity, thus contributing to a significant reduction of the genotoxic and cytotoxic risk in the gut
On the Modeling of Electrical Effects Experienced by Space Explorers During Extra Vehicular Activities: Intracorporal Currents, Resistances, and Electric Fields
Recent research has shown that space explorers engaged in Extra Vehicular Activities (EVAs) may be exposed, under certain conditions, to undesired electrical currents. This work focuses on determining whether these undesired induced electrical currents could be responsible for involuntary neuromuscular activity in the subjects, possibly caused by either large diameter peripheral nerve activation or reflex activity from cutaneous afferent stimulation. An efficient multiresolution variant of the admittance method along with a millimeter-resolution model of a male human body were used to calculate induced electric fields, resistance between contact electrodes used to simulate the potential exposure condition, and currents induced in the human body model. Results show that, under realistic exposure conditions using a 15V source, current density magnitudes and total current injected are well above previously reported startle reaction thresholds. This indicates that, under the considered conditions, the subjects could experience involuntary motor response
Influence of Processing Parameters and Natural Antimicrobial on Alicyclobacillus acidoterrestris and Clostridium pasteurianum Using Response Surface Methodology
The food industry must ensure the stability of the products, and this is often achieved by exposing foods to heat treatments that are able to ensure the absence of pathogenic or spoilage microorganisms. These treatments are different in terms of temperature and duration and could lead to a loss in nutritional and sensory value. Moreover, some types of microorganisms manage to survive these treatments thanks to the sporification process. The addition of antimicrobials can become necessary, but at present, consumers are more inclined toward natural products, avoiding synthetic and chemical additives. Antimicrobials from plants could be a valuable option and, in this context, a patent concerning an antimicrobial extract from fermented plant substrate was recently tested against foodborne pathogens revealing high antimicrobial activity. The objective of this study was the creation of a model for the evaluation and subsequent prediction of the combined effect of different process and product variables, including antimicrobial addition, on the inhibition and reduction of spore germination of target microorganisms, Alicyclobacillus acidoterrestris and Clostridium pasteurianum, responsible for spoilage of tomato-based products
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