341 research outputs found

    Nonlinear Ionic Conductivity of Thin Solid Electrolyte Samples: Comparison between Theory and Experiment

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    Nonlinear conductivity effects are studied experimentally and theoretically for thin samples of disordered ionic conductors. Following previous work in this field the {\it experimental nonlinear conductivity} of sodium ion conducting glasses is analyzed in terms of apparent hopping distances. Values up to 43 \AA are obtained. Due to higher-order harmonic current density detection, any undesired effects arising from Joule heating can be excluded. Additionally, the influence of temperature and sample thickness on the nonlinearity is explored. From the {\it theoretical side} the nonlinear conductivity in a disordered hopping model is analyzed numerically. For the 1D case the nonlinearity can be even handled analytically. Surprisingly, for this model the apparent hopping distance scales with the system size. This result shows that in general the nonlinear conductivity cannot be interpreted in terms of apparent hopping distances. Possible extensions of the model are discussed.Comment: 7 pages, 6 figure

    Contribution of macrophages to plasmin activity in ewe bulk milk

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    A total of 225 bulk sheep milk samples were collected throughout lactation to assess the contribution of macrophages to the regulation of the plasmin/plasminogen system. Samples were analyzed for composition, milk renneting parameters, and for activities of plasmin (PL), plasminogen (PG) and plasminogen activators (PA). Isolation of macrophages from milk was performed using a magnetic positive separation; separated cells were lysed and activity of urokinase-PA was determined. PL activity in milk decreased during lactation (P < 0.001). The reduction in plasmin activity recorded in the mid and late lactation milk matched with the increase in PG/PL ratio (P < 0.001). The activity of PA increased throughout lactation (P < 0.001), the highest value being recorded in the late lactation milk.The amount of isolated and concentrated macrophages was higher in early and mid lactation milk than in late lactation milk (P < 0.01). Stage of lactation did not influence the activity of u-PA detected in isolated macrophages. The activity of u-PA associated with macrophages was lower than total PA activity detected in milk. Our results lend support to the hypothesis that in ewe bulk milk from healthy flocks macrophages only slightly contributed to the activation of plasmin/plasminogen system

    sustainability of sheep and goat production systems

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    Sustainability of sheep and goat production systems has been investigated in this chapter in terms of environmental, social, and economic sustainability. Strategies to reduce waste from animal husbandry activities and the negative impact of animal husbandry on environment have been described. Social sustainability has been analyzed in relation to animal welfare and human–animal relationship. Economic sustainability of sheep and goat production systems in the Mediterranean countries has been addressed in terms of animal management plans to improve animal health, quality of products, and increase profitability of animal production systems. In particular, strategies to change the basic standard for sheep and goat productions into high standard of nutritional, hygienic, and technological quality have been analyzed

    Rennet paste from lambs fed a milk substitute supplemented with Lactobacillus acidophilus: effects on lipolysis in ovine cheese.

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    The present work was undertaken to evaluate the effects of Lactobacillus acidophilus supplementation of a milk substitute on the features of lamb rennet paste used for cheese making. Lipolysis in cheese manufactured with rennet paste from lambs receiving supplemented milk was also evaluated. Lambs were subjected to 3 different feeding regimens (mother suckling, MS; artificial rearing, AR; and artificial rearing with 7 log10 cfu/mL of Lb. acidophilus supplementation of the milk substitute, ARLb) and slaughtered at 20 and 40 d of age for each feeding treatment. Abomasa of the lambs were processed to rennet paste. Microbial loads, enzymatic activities (chymosin, pepsin, and lipases), and renneting characteristics of the lamb rennet paste were determined. Free fatty acids and conjugated linoleic acids were detected in cheese at 60 d of ripening. Addition of 7 log10 cfu/mL of Lb. acidophilus to the milk substitute was carried out successfully. Total recovery of viable cells was recorded in milk supplied daily to the lambs in the ARLb group. The ARLb rennet had greater amounts of lactobacilli than did the MS or AR rennet, irrespective of the slaughter age of the lambs, and the ARLb rennet had higher concentrations of lactococci when lambs were slaughtered at 40 d of age. Chymosin and lipase activities were also higher in ARLb rennet than in MS or AR rennet from lambs slaughtered at an older age. Milk supplementation of ARLb lambs resulted in improved coagulating ability of the rennet and enhanced cheese lipolysis after 60 d of ripening. A reduction of all free fatty acids was observed in all cheeses when passing from 20 to 40 d of slaughter of the lambs. Conjugated linoleic acids were more abundant in ARLb cheeses at both 20 and 40 d. Therefore, supplementation of the milk substitute with Lb. acidophilus improved the enzymatic features of rennet and the healthful and nutritional characteristics of it the ovine cheese. Moreover, the addition of lactobacilli to the milk substitute made it possible to increase the slaughter age of lambs without detrimental effects on rennet characteristics

    Functional Properties of Meat in Athletes’ Performance and Recovery

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    Physical activity (PA) and sport play an essential role in promoting body development and maintaining optimal health status both in the short and long term. Despite the benefits, a long-lasting heavy training can promote several detrimental physiological changes, including transitory immune system malfunction, increased inflammation, and oxidative stress, which manifest as exercise-induced muscle damages (EIMDs). Meat and derived products represent a very good source of bioactive molecules such as proteins, lipids, amino acids, vitamins, and minerals. Bioactive molecules represent dietary compounds that can interact with one or more components of live tissue, resulting in a wide range of possible health consequences such as immune-modulating, antihypertensive, antimicrobial, and antioxidative activities. The health benefits of meat have been well established and have been extensively reviewed elsewhere, although a growing number of studies found a significant positive effect of meat molecules on exercise performance and recovery of muscle function. Based on the limited research, meat could be an effective post-exercise food that results in favorable muscle protein synthesis and metabolic performance

    La rintracciabilità di razza della carne ovina mediante marcatori molecolari STR: risultati preliminari

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    La ricerca propone la messa a punto di un sistema di rintracciabilità della carne ovina mediante metodiche di genetica molecolare. Sono stati tipizzati mediante 19 marcatori STR un totale di 800 campioni di cui: (a) 90 appartenenti a un gruppo costituito sia da soggetti di importazione di razza indefinita che da prodotti di incrocio locali reperibili presso macelli e punti vendita; (b) i restanti campioni appartenenti a sette razze ovine autoctone dell’Italia Centro-Meridionale. È stato adottato un test di assegnazione di tipo probabilistico per valutare la possibilità di attribuire i singoli campioni alla propria razza d’origine. Tutti i campioni di razza Sarda sono risultati correttamente assegnati, così come oltre il 98% dei campioni delle altre razze. I risultati preliminari sembrano molto promettenti, anche se ulteriori analisi si rendono necessarie per meglio comprendere la potenza statistica di un simile test di assegnazione razziale prima di inserirlo nella catena di produzione della carne ovina

    Chlamydia trachomatis infection of human endometrial stromal cells induces defective decidualisation and chemokine release

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    Miscarriage affects ~20% of pregnancies and 30 maternal infections account for ~15% of early miscarriages. Chlamydia trachomatis (Ct) has been associated with miscarriage but the underlying mechanisms are unknown. Successful implantation requires endometrial stromal cell (ESC) decidualisation. Maintenance of pregnancy requires angiogenesis, establishment of the correct cellular milieu and trophoblast invasion, all of which involve the action of chemokines. Our objective was to determine whether Ct infection impacts upon ESC decidualisation and chemokine secretion. Human primary ESC were decidualised in-vitro, infected with Ct serovar E, and changes in expression of genes of interest were measured using RT-PCR, proteomic array and ELISA. We demonstrate for the first time that Ct can infect and proliferate in ESC. Expression of the decidualisation marker prolactin was decreased in Ct-infected ESC at both mRNA and protein levels. Ct infection altered the chemokine profile of decidualised ESC as shown by proteomic array. Chemokines CXCL12 and CXCL16, important for trophoblast invasion, were analysed further and expression was reduced in infected decidualised cells at mRNA and protein levels. Our data indicate that Ct infection of ESC impairs decidualisation and alters chemokine release. These findings at least partially explain how Ct infection could result in adverse pregnancy outcomes
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