Field reliability of GaAs emitters for fiber optic telecommunication systems

GaAs based emitters are widely used in telecommunication systems, and will be probably the core of short haul communications, even if a lot of doubts still exist on their reliability and the few available field results are not too optimistic. For these reasons we decided to follow with a particular attention all the problems related to these devices, investigating reliability by means of accelerated tests and of an accurate survey of field troubles. In this paper, we first of all report our field data, coming from more than five years experience, which show that "reasonable" results (in the range of 2000 FITs for LDs), can be obtained with commercially available devices; as a second step, failure analysis allows to localize failures,thus understanding the appropriate corrective actions to be taken. highlighting the specific process report also same For chip related failures, detailed examples are reported, different failure mechanisms, that, when not related to defects, are the same found during accelerated tests; we examples of failures due to interconnections and packaging

IDENTIFICATION OF E. COLI O157 IN A BOVINE MILK FARM BY MULTIPLEX REAL-TIME PCR

Law provisions about direct sell of raw bovine milk require VTEC O157 monitoring in bovine milk farms (milk and faeces). It has been showed that culture-based methods used for this scope, besides being cumbersome and time-consuming, may be also less sensitive, compared to molecular approaches. In this study, a multiplex Real-Time PCR, able to identify VTEC O157, Salmonella spp and Listeria monocytogenes, has been used to analyse milk, filter, sewage and stool samples from a milk farm, in comparison with standard OIE methods. The performances of the molecular protocol have been preliminary assessed with lyophilized samples from proficiency testing VLA, showing 100% accordance. Results from field samples indicated the absence of the pathogen in milk, and the higher sensitivity of Real-Time PCR with other matrices, suggesting its potential use for fast VTEC O157 identification

Is the Salmonella contamination of swine carcasses at slaughter related to the Salmonella load in caecum?

The aim of this study was to examine the relationship between the load of Salmonella spp. in caeca and the carcass contamination in an Italian slaughterhouse. The sampling scheme was designed to be representative of the pigs slaughtered in a day and to estimate a 12% prevalence of pigs highly contaminated by Salmonella spp. (HCP, cecal load ≥3log). Environmental swabs were taken before slaughter. Cecal contents and carcass swabs were collected from the same pig. Salmonella MPN were estimated according to ISO6579- 2:2012/A1 and ISO7218:2007/E. The overall Salmonella prevalence were 34.64% and 7.19% for ceca and carcasses respectively, with S. Derby and S. 4,[5],12:i:- being the prevalent serotypes. The HCP prevalence was 11.44%. 7/59 environmental swabs tested positive; when the same serotype was isolated from the environment and from carcasses, the samples were excluded from further analysis. Statistical analysis was performed to investigate the relationship between Salmonella spp. loads in the cecum and contamination of the carcass of the same pig and the prevalence of HCP and the contamination of carcasses on the same day. For this purpose, the days were classified as “high prevalence days” depending on the proportion of caeca resulted positive (≥36%) and as “high load” days depending on the prevalence of HCP (≥10%). A correlation between the contamination of carcasses and the cecal Salmonella loads of the same animal was found (Spearman’s correlation coefficient: 0.2254; p-value=0.0001). No correlation was found between the contamination of carcasses and the categorization of the day of sampling as “high prevalence day”. Conversely, a correlation was found between the contamination of carcasses and the “high load” category of the sampling day (Wilcoxon test, p=0.0011). Notably, not the prevalence of pigs carrying Salmonella spp. but the prevalence of highly contaminated pigs was shown to be related to the contamination of carcasses

Farm efficiency related to animal welfare performance and management of sheep farms in marginal areas of Central Italy: a two-stage DEA model

The development of specific actions to increase animal health and welfare is indicated as a strategy to improve the efficiency and sustainability of many livestock systems, including sheep farming. In this paper, efficiency measures are provided to confirm the hypothesis that farms that are higher-performing in terms of animal welfare and management are also more technically efficient. A two-stage Data Envelopment Analysis (DEA) approach was adopted with the following twofold objectives: 1) to evaluate the efficiency and super-efficiency of 76 meat-producing sheep farms situated in marginal lands in central Italy, through DEA and Super-DEA (S-DEA) models; and 2) to assess the influence of animal welfare and management indicators on technical efficiency values through the application of a Tobit regression model. An overall efficiency performance varying within a range of 0.44–1 was estimated, with an average value of 0.80, implying a potential increase of 20% in terms of output production from both management and scale improvements. The ‘pure’ technical inefficiency was found to contribute three times more than scale inefficiency in determining the overall technical inefficiency. Adopting a more extensive farming system and increasing replacement rate were found to affect negatively the efficiency scores. On the other hand, having less than 5% of animals with body condition score beyond acceptable limits, presence of access control structures, well managed lambing pens, and dedicated feed stocking areas resulted in a positive influence on efficiency. Improvements in animal welfare aspects did not appear to be farm-scale-dependent.Highlights DEA and Super-DEA models were applied to assess sheep farm technical efficiency in Central Italy. An overall potential 20% increase in output production was estimated. Animal welfare factors were found to significantly affect efficiency performance

Dietary Saccharomyces cerevisiae boulardii CNCM I-1079 positively affects performance and intestinal ecosystem in broilers during a campylobacter jejuni infection

In poultry production, probiotics have shown promise to limit campylobacteriosis at the farm level, the most commonly reported zoonosis in Europe. The aim of this trial was to evaluate the effects of Saccharomyces supplementation in Campylobacter jejuni challenged chickens on performance and intestinal ecosystem. A total of 156 day old male Ross 308 chicks were assigned to a basal control diet (C) or to a Saccharomyces cerevisiae boulardii CNCM I-1079 supplemented diet (S). All the birds were orally challenged with C. jejuni on day (d) 21. Live weight and growth performance were evaluated on days 1, 21, 28 and 40. The histology of intestinal mucosa was analyzed and the gut microbiota composition was assessed by 16S rRNA. Performance throughout the trial as well as villi length and crypt depth were positively influenced by yeast supplementation. A higher abundance of operational taxonomic units (OTUs) annotated as Lactobacillus reuteri and Faecalibacterium prausnitzii and a lower abundance of Campylobacter in fecal samples from S compared to the C group were reported. Supplementation with Saccharomyces cerevisiae boulardii can effectively modulate the intestinal ecosystem, leading to a higher abundance of beneficial microorganisms and modifying the intestinal mucosa architecture, with a subsequent improvement of the broilers' growth performance

Reproductive cycle, number of parities and faecal Salmonella spp. excretion in sows: a longitudinal study

The aim of the study was to evaluate the fecal excretion of Salmonella spp in sows with different number of parties, in distinct periods of the reproductive cycle. Two integrated farms in central Italy have been included in the study. The target populations were primaparous and multiparous (1-5 and more than 5 parities) sows, tested in different periods of the reprouductive cycle: 14 days before parturition (pre-partum), 2-5 days (post-partum), 20 days after parturition (post-partum 2) and gestation (24-31 days post-partum)