The free path in a high velocity random flight process associated to a Lorentz gas in an external field

We investigate the asymptotic behavior of the free path of a variable density random flight model in an external field as the initial velocity of the particle goes to infinity. The random flight models we study arise naturally as the Boltzmann-Grad limit of a random Lorentz gas in the presence of an external field. By analyzing the time duration of the free path, we obtain exact forms for the asymptotic mean and variance of the free path in terms of the external field and the density of scatterers. As a consequence, we obtain a diffusion approximation for the joint process of the particle observed at reflection times and the amount of time spent in free flight.Comment: 30 page

Ready to Eat Nectarines - Assuring Quality in the Chain

Time-resolved reflectance spectroscopy, coupled to the modelling of firmness decrease, was used to predict at harvest softening behaviour of nectarines. Selected fruit were used in an export trial from Italy to The Netherlands. Quality assessed after shelf life was in agreement with the predicted firmness for fruit of different stages of maturity, showing that it is possible to select fruit at harvest for different market destinations and prevent transportation of fruit unsuitable for consumption

Matemática, Literatura & Aulas

A aprendizagem da Matemática não ocorre por mera transmissão de saberes do professor para os alunos. A ideia de que o conhecimento pode passar linearmente de uma cabeça – daquele que sabe – para outra(s) cabeça(s) – para aqueles que querem saber –, pelas palavras ditas e escritas, não tem qualquer correspondência com a realidade. A aprendizagem é um processo adaptativo, simultaneamente individual e coletivo, baseado na ação e na reflexão, no qual a comunicação tem um papel fundamental, na medida que permite estabelecer ligação entre as pessoas

Maturação de tubérculos da cultivar de batata BRS Ana.

bitstream/item/82142/1/Boletim-166-1.pd

SULT1A1gene deletion inBRCA2-associated male breast cancer: a link between genes and environmental exposures?

SULT1A1, a member of sulfotransferase superfamily, is a drug and hormone metabolizing enzyme involved in the metabolism of a variety of potential mammary carcinogens of endogenous and exogenous origin. Interestingly, the metabolic activity of SULT1A1 can be affected by varia- tions in gene copy number. Male Breast Cancer (MBC) is a rare disease and less investigated disease compared to female BC (FBC). As in FBC, the concurrent effects of genetic risk factors, particularly BRCA2 mutations, increased exposure to estrogens and environmental carcinogens play a relevant role in MBC. By quantitative real-time PCR with TaqMan probes, we investigated the presence of SULT1A1 gene copy number variations (CNVs) in a series of 72 MBCs. SULT1A1 gene deletion was observed in 10 of the 72 MBCs (13.9%). In a multivariate analysis associ- ation between BRCA2 mutation and SULT1A1 gene deletion emerged (p = 0.0005). Based on the evidence that the level of SULT1A1 enzyme activity is correlated with CNV, our data suggest that in male breast tumors SULT1A1 activity may be decreased. Thus, it can be hypothesized that in a proportion of MBCs, particularly in BRCA2-associated MBCs, the level of estrogens and environmental carcinogens exposure might be increased suggesting a link between gene and environmental exposure in the pathogenesis of MBC

Preferências do consumidor de batatas no sul do Estado do Rio Grande do Sul.

bitstream/item/31487/1/comunicado-212.pd

COLORECTAL CANCER IN PATIENTS WITH TYPE 2 DIABETES MELLITUS: PRELIMINARY RESULTS FROM AN ONGOING CASE-CONTROL STUDY

Background and Aim:Understanding the risk factors for colorectal cancer (CRC) is crucial to the development of effective strategies for its prevention. meta-analysis and epidemiological studies have already shown that type 2 diabetes mellitus (DM) is associated with an increased risk of CRC and have provided data to support a positive relationship between these diseases. Material and Methods: We retrospectively evaluated 741 consecutive caucasian patients with type 2 DM who underewnt colonoscopic screening cof CRC and followed in our tertiary referrral center in 200-208 for incidence of CRC. Patients were stratified based on gender, age, body mass index (MBI), alchool and NSAIDS assumption, family history for cancer blood glycated hemoglobin levels, hypertension, hypertrigliceridemia, age at diabetes onset and duration, treatment with insulin or other hypoglicemic drugs. A total of 257 consecutive control patients were selected from a cohort of patients followed as outpatients for thyroid diseases. Results: At a median follow-up of 132,5 months (range 33,3-175,7) 56 cases of cancer (prevalence 7,56%) occurred; among these, 14 cases of CRC were reported (prevalence 18,8%) among the diabetic patients, while only one case (prevalence 0,004%) occurred in the control group, although this difference is not statistically significant (chi-square 2,9, P=0,08). Median duration of DM to CRC diagnosis was 156 months (range 1-768). At the univariate analysis older age (p=0,001), and diabetes duration (p=0,001) were related to higher risk of cancer, while metformin seems to be protective towards cancer (p=0,058). in the subset of patients with CRC, older age (p=0,001) and diabetes duration (p=0,001) were related to higher risk of CRC, such as treatment with sulphonylureas (p=0,01). Conclusions: Our preliminbar data show that the prevalence of CRC in the cohort of patients with type 2 DM was higher compared to that from our control group, and to that from the National Tumor Register up 2010 (0,5%). Furthermore we could interestingly hypotize that sulphonylureas may play a role in CRC carcinogenesis altering the physiological insulin secretion

A first attempt to produce proteins from insects by means of a circular economy

The worldwide growing consumption of proteins to feed humans and animals has drawn a considerable amount of attention to insect rearing. Insects reared on organic wastes and used as feed for monogastric animals can reduce the environmental impact and increase the sustainability of meat/fish production. In this study, we designed an environmentally closed loop for food supply in which fruit and vegetable waste from markets became rearing substrate for Hermetia illucens (BSF\u2014 black soldier fly). A vegetable and fruit-based substrate was compared to a standard diet for Diptera in terms of larval growth, waste reduction index, and overall substrate degradation. Morphological analysis of insect organs was carried out to obtain indications about insect health. Processing steps such as drying and oil extraction from BSF were investigated. Nutritional and microbiological analyses confirmed the good quality of insects and meal. The meal was then used to produce fish feed and its suitability to this purpose was assessed using trout. Earthworms were grown on leftovers of BSF rearing in comparison to a standard substrate. Chemical analyses of vermicompost were performed. The present research demonstrates that insects can be used to reduce organic waste, increasing at the same time the sustainability of aquaculture and creating interesting by-products through the linked bio-system establishment