Models of Fractal River Basins

Two distinct models for self-similar and self-affine river basins are numerically investigated. They yield fractal aggregation patterns following non-trivial power laws in experimentally relevant distributions. Previous numerical estimates on the critical exponents, when existing, are confirmed and superseded. A physical motivation for both models in the present framework is also discussed.Comment: 16 pages, latex, 9 figures included using uufiles command (for any problem: [email protected]), to be publishes in J. Stat. Phys. (1998

The term risk: etymology, legal definition and various traits

open5noThe etymology of the term risk and its legal qualification and definitions are reported in this article; decription of the various traits of the term risk used in food safety management (acceptable risk, current risk, emerging risk, crude risk, unrestricted risk, perceived risk, real risk, residual risk, reduced risk, baseline risk, serious risk, major technological risk, etc.) are presented and discussed.openLiuzzo G.; Bentley S.; Giacometti F.; Bonfante E.; Serraino A.Liuzzo G.; Bentley S.; Giacometti F.; Bonfante E.; Serraino A

Evaluation of bovine beta casein polymorphism in two dairy farms located in northern Italy

Bovine beta casein A1 is one of the most common variants in dairy cattle breeds; it is considered a risk factor in milk intolerance and in other important human diseases, because of the bioactive peptide beta casomorphin-7 (BCM7) produced by raw or processed A1-milk, but not by A2-milk, during digestion. The aim of this study was to perform a cheap and rapid method to investigate beta casein polymorphism in copious animals. The study included 2 dairy farms with a totally of 1230 cows. Beta casein genotypes were estimated evaluating Exon 7 region of bovine beta casein gene (CSN2) by sequences analysis. In the population included in the study 5 variants (A1, A2, B, F, I) and 13 genotypes (A1A1, A1A2, A1B, A1F, A1I, A2A2, A2B, A2F, A2I, BB, BF, BI, FI) were detected. The method showed high sensibility and specificity, resulted low-cost and few time consuming

Fecal shedding of thermophilic Campylobacter in a dairy herd producing raw milk for direct human consumption.

Factors affecting the thermophilic Campylobacter fecal shedding in Italian dairy farming conditions have been investigated in a 12-month longitudinal study performed in a dairy farm authorized to sell raw milk in Italy. Fifty animals were randomly selected from 140 adult and young animals, and fecal sampling was performed six times at two month intervals; additionally at each sampling, three trough water samples and two trough feed samples were collected for both adult and young animals. Samples were analyzed by real-time PCR and cultural examination. Overall 33 samples (9.7%) were positive for thermophilic Campylobacter by real-time PCR: 26 out of 280 (9.2%) fecal samples, six out of 36 water points (16.6%) and one of the 24 feed samples (4.2%). Campylobacter jejuni was isolated from 6 out of 280 samples; no other Campylobacter sp. was isolated. A higher but not significant positivity was observed in fecal samples of younger animals (11.33%% versus 6.92% of adult animals) and a higher and significant positivity was observed in water samples collected from the water troughs of young animals. A distinct temporal dynamic trend was observed during the study period for both cows and calves, with two prevalence peaks between November/December and between May/July. Several factors such as calving, housing practices, herd size, management practices forcing together a higher number of animals, variations in feeding or water source, which were previously reported as cause of temporal variation in different farming conditions, could be excluded as cause of the two seasonal peaks in this study. The factors affecting the seasonality of Campylobacter shedding in the dairy herds remain unclear and warrant further investigation. The results of the present study indicate that special attention should be paid to farm hygiene management in farms authorized to produce and sell raw milk with increased surveillance by the authorities in certain periods of the year

On Hack\u27s Law

Hack\u27s law is reviewed, emphasizing its implications for the elongation of river basins as well as its connections with their fractal characteristics. The relation between Hack\u27s law and the internal structure of river basins is investigated experimentally through digital elevation models. It is found that Hack\u27s exponent, elongation, and some relevant fractal characters are closely related. The self-affine character of basin boundaries is shown to be connected to the power law decay of the probability of total contributing areas at any link and to Hack\u27s law. An explanation for Hack\u27s law is derived from scaling arguments. From the results we suggest that a statistical framework referring to the scaling invariance of the entire basin structure should be used in the interpretation of Hack\u27s law

A screening sampling plan to detect Mycobacterium avium subspecies paratuberculosis-positive dairy herds

Abstract Mycobacterium avium ssp. paratuberculosis (MAP) is the etiological agent of paratuberculosis, a chronic contagious bacterial disease primarily affecting dairy cattle. Paratuberculosis represents a dual problem for the milk production chain: in addition to economic losses to affected herds, MAP may have zoonotic potential. Infected herds must be identified in order to implement programs designed to reduce the incidence of disease within and between herds and to prevent MAP from entering the food chain. The objective of this study was to evaluate the sensitivity and specificity of a screening sampling plan (SSP) to detect MAP-positive dairy herds by repetitive analysis of bulk tank milk (BTM) samples by ELISA and in-line milk filter (ILMF) samples by PCR. Samples from BTM and ILMF were collected twice from 569 dairy herds in southern Italy. Additionally, 12,016 individual milk samples were collected: 9,509 from 102 SSP-positive herds (SSP MAP-positive) and 2,507 from 21 randomly selected SSP-negative herds (SSP MAP-negative). There was a total of 126 SSP MAP-positive herds (i.e., 21.3% SSP MAP-positive herds; 95% confidence interval=18.0–24.9); the within-herd apparent prevalence (AP) ranged between 0.00 and 22.73% (mean 6.07%). A significant difference in within-herd AP was shown between SSP MAP-positive herds and SSP MAP-negative herds. A highly significant association was shown between the median AP herd status (>5%) and positivity to at least one ILMF or BTM sample. The SSP detected a minimum of 56.25% of low AP herds (AP ≤2.0%) up to a maximum of 100% of herds with a within-herd AP ≥8.0%. Overall, the SSP detected 85.57% of herds in which at least one individual milk sample was positive by ELISA. The proposed SSP was an inexpensive and useful tool to detect MAP-positive herds with a higher risk of infection diffusion and milk contamination. Although the SSP cannot be used for MAP-free certification of herds, it could be useful to prioritize appropriate control measures aimed at reducing the prevalence of infection in dairy herds and milk contamination

Role of Daptomycin in Cutaneous Wound Healing: A Narrative Review

Daptomycin is active against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and the on-label indications for its use include complicated skin and skin structure infections (cSSSI). We performed a narrative review of the literature with the aim to evaluate the role of daptomycin in the skin wound healing process, proposing our point of view on the possible association with other molecules that could improve the skin healing process. Daptomycin may improve wound healing in MRSA-infected burns, surgical wounds, and diabetic feet, but further studies in humans with histological examination are needed. In the future, the combination of daptomycin with other molecules with synergistic action, such as vitamin E and derivates, IB-367, RNA III-inhibiting peptide (RIP), and palladium nanoflowers, may help to improve wound healing and overcome forms of antibiotic resistanc

Food safety objectives, criteria, ranking and hierarchization

The paper describes the terminology of risk in the view of food safety objectives, criteria, ranking and hierarchization: the terms Performance Criterion, Process Criteria, Product Criterion, Microbiological Criteria, Food Safety Objective, Performance standard, Food safety policy objectives, Risk Assessment Policies, Weighing, Precaution, Prevention, Precautionary principle, Prevention principle, Principle of separation between risk assessment and management, Rank, Ranking, Categorization, Ranking, Priorization, ALARA (As Low Reasonably Achievable), ALOP (Appropriate level of protection), Risk Management, Risk management in the public function are reported and discussed

Evaluation of pre-slaughter losses of Italian heavy pigs

A retrospective observational study evaluated the risk factors for pre-slaughter losses (i.e. animal deaths occurring during transport and lairage) and their economic impact in Italian heavy pigs (about 160 kg body weight). Of the 3,344,730 pigs transported, 1,780 (0.053%) died before slaughter, with most losses occurring during transport (56.6%). The estimated economic impact was of \ue2\u82\uac 424,000. The percentage of batches with at least one animal lost pre-slaughter increased during summer (P<0.001). The proportion of pre-slaughter losses was higher when journey lasted above 90 min (P<0.001) and was correlated with transport duration (P<0.01). Losses were higher (P<0.01) in batches transported at low stocking densities (i.e., when heavier pigs were transported). Batches with lower slaughtering order (i.e., longer lairage time) had higher proportions of losses (P<0.001). Logistic regression analysis showed that the odds of a given batch to have at least one animal lost pre-slaughter were 1.32 times higher for batches slaughtered in summer, 1.54 times higher if journey durations exceeded 90 min, 1.25 times higher for batches with low slaughtering order, and not significantly influenced by stocking density during transport