Influence of fine fraction on breakage of binary granular materials

Understanding the stress transmission mechanisms and breakage of soils composed of a fine and coarse fractions is critical for the design of many geotechnical structures such as pile driving and large embankment dams. A series of strain controlled one-dimensional compression laboratory experiments were carried out using glass beads to investigate the effect of the fine faction on the macroscopic response of the material. A wide range of stress varying from 10 to 250MPa was considered. Glass beads with diameters between 0.5 and 4mm were used to form granular mixtures with fines content ranging from 0 to 100%. This study shows the potential of strain controlled testing to provide further insights into the fabric evolution of granular materials undergoing grain breakage. When compared to conventional load controlled testing, the force:displacement curve obtained during strain controlled testes provides a better correlation between the macroscopic response and the grain-scale phenomena. The response of mono-sized samples is used as a reference to better understand the contribution of both the coarse and the fine factions to the behaviour of the mixture. Preliminary results have suggested that as breakage progresses, the grain size distribution evolves towards a fine fraction threshold value, beyond which the behaviour is governed by the fine component. Previously proposed relative breakage parameters are also used to demonstrate the influence of the fine faction in the final grading of the material. These finding, also supported by recent numerical studies, can provide valuable guidance for geotechnical practice

Behavior of Aeromonas hydrophila in Bottled Mineral Waters

The growth and survival of Aeromonas hydrophila in three types of natural mineral waters were investigated. Mineral waters with different levels of mineral content (low, medium, and high) were experimentally contaminated with A. hydrophila, stored at different temperatures (10 degrees C and 20 degrees C), and analyzed at intervals over a 60-day period. Water samples that were not experimentally contaminated were investigated for indigenous A. hydrophila. The results confirmed that A. hydrophila may occur naturally in mineral waters and showed that the level of mineral content, temperature, length of storage, and, in some cases, the type of container used may favor the growth of A. hydrophila. The greatest proliferation was observed in water with a low mineral content stored in PET bottles at 10 degrees C, in which A. hydrophila peaked at day 28 (4.47 +/- 0.01 log CFU/100 ml). At 20 degrees C, the same load was observed at day 60. The presence of high densities of A. hydrophila in bottled mineral water can constitute a risk for some groups of consumers, such as elderly and immunocompromised persons

Molecular marketing, personalised information and willingness-to-pay for functional foods: Vitamin D enriched eggs

Increasingly, the health claims made by food products focus on the marketing of specific molecular enrichments. Research exploring consumers’ willingness to pay (WTP) for health claims assumes that individuals hold perfect information on the benefits of the enrichment, and that their valuations depend solely on whether or not they need to improve their health. While health interventions are aimed at individuals at higher health risk, consumers may be unaware of the health risks that they face, limiting the effectiveness of a generic targeting strategy. Using an orthogonal experimental design, we explore the impact of two factors on the WTP for vitamin D enrichment in eggs: whether the information is person-specific or generic; and the presence of a health claim explaining the vitamin D enrichment. Results indicate that it is the provision of information, not the health claim, that influences WTP. Both generic and personalised information lead to similar increases in the WTP for vitamin D enrichment. While we only observe a direct effect of generic information on the WTP for vitamin D enrichment, personal information may also operate by increasing the perceived risk of vitamin D deficiency. Our results support the use of personalised health information during the choice task as a means of increasing the sales of healthy products

Radiative Inflation and Dark Energy

We propose a model based on radiative symmetry breaking that combines inflation with Dark Energy and is consistent with the WMAP 7-year regions. The radiative inflationary potential leads to the prediction of a spectral index 0.955 \lesssim n_S \lesssim 0.967 and a tensor to scalar ratio 0.142 \lesssim r \lesssim 0.186, both consistent with current data but testable by the Planck experiment. The radiative symmetry breaking close to the Planck scale gives rise to a pseudo Nambu-Goldstone boson with a gravitationally suppressed mass which can naturally play the role of a quintessence field responsible for Dark Energy. Finally, we present a possible extra dimensional scenario in which our model could be realised.Comment: 15 pages, 4 figures; v2: references added, appendix added, Section 5 slightly modified; content matches published versio

SYBR Green Real-Time PCR for Salmonella detection in meat products

The objective of this study was to develop a SYBR Green Real-Time PCR method for detecting salmonellae in meat samples. The study was conducted both on S. Typhimurium experimentally and naturally contaminated meat samples analyzed in parallel with the standard cultural method (ISO 6579/2001). After the pre-enrichment phase, a boiling DNA extraction procedure combined wity SYBR-Green I Real Time PCR, using primers Styinva-JHO-2, was developed

A Systematic Analysis of the Memory term in Coarse-Grained models: the case of the Markovian Approximation

The systematic development of Coarse-Grained (CG) models via the Mori-Zwanzig projector operator formalism requires the explicit description of several terms, including a deterministic drift term, a dissipative memory term and a random fluctuation term. In many applications, the memory and fluctuation terms are related by the fluctuation-dissipation relation and are, in general, more challenging to derive than the drift term. In this work we analyse an approximation of the memory term and propose a rational basis for a data-driven approach to an approximation of the memory and fluctuating terms which can be considered included in the class of the Markovian ones.Comment: 39 pages, 2 Figure

Animal Welfare and Parasite Infections in Organic and Conventional Dairy Farms: A Comparative Pilot Study in Central Italy

The study investigated and compared welfare conditions and gastrointestinal (GI) parasites distribution among organic (ORG) and conventional (CONV) farms in central Italy. Five ORG and five CONV farms were assessed for animal welfare with an adapted version of the AssureWel protocol. Faecal samples collected from the rectum of the animals both in ORG (n = 150) and CONV (n = 150) were analysed using conventional copromiscroscopy. The presence of skin damages in the rear legs was significantly predominant (p < 0.001) in CONV (26.7%) compared with ORG farms (10.0%). No differences were found for lameness, cleanliness, Body Condition Score, hair loss, body lesions and swelling prevalence. Data concerning the productive performances, e.g., total milk, fat and protein yields standardised in mature equivalent (ME) were collected. ME milk yield (ORG: 9656.9 ± 1620.7 kg; CONV: 12,047.2 ± 2635.3) and ME fat yield (ORG: 396.6 ± 66.8; CONV: 450.3 ± 102.8) were significantly lower in ORG farms (p < 0.001). Anthelmintics were used regularly in 4/5 CONV and 0/5 ORG farms. In 2 CONV farms (40%) and 4 ORGs (80%) at least one animal tested positive for GI parasites. No significant differences in parasites prevalence emerged (ORG = 10.7%; CONV = 8%). These data indicate that ORG farming does not influence parasite prevalence and animal welfare status