Deployment of Sawdust as Substrate Medium in Hydroponically Grown Lettuce

In this study, lettuce plants were grown in sawdust (Saw) and/or perlite (Per) mixtures (sawdust; Saw:Per 75:25%; Saw:Per 50:50%; Saw:Per 25:75%; Perlite) and in Nutrient Film Technique (NFT), in an unheated greenhouse. Plants grown in NFT were taller with greater leaf area resulting in greater fresh weight. Sawdust addition reduced leaf length, leaf area and as a consequence the fresh weight but not the leaf number. However, leaf dry weight increased as sawdust content increased into the substrate. Leaf chlorophyll reduced but leaf fluoresces increased in perlite and NFT. High sawdust content (75% or 100%) reduced photosynthetic rates and stomatal conductance. Nutrient uptake [potassium (K), sodium (Na), phosphorus (P)] was the greatest in NFT treatment, while perlite and Saw:Per 25:75% increased elemental uptake (up to 74%) comparing with the remaining treatments. Leaf elemental analysis fluctuated among treatments. Thus, low content (i.e. 25%) of sawdust in perlite could improve inorganic substrate media properties.     

Molecular characterization of Mycobacterium tuberculosis complex isolates from wild ungulates in south-central Spain

The role of European wild ungulates in the epidemiology of tuberculosis (TB) is still under discussion. This study describes the geographical distribution and molecular typing of 77 Mycobacterium tuberculosis complex isolates belonging either to M. bovis or to M. caprae, cultivated from hunter harvested red deer (Cervus elaphus) and European wild boar (Sus scrofa) in 24 Spanish localities, and compares them with spoligotypes detected previously in humans, livestock or wild animals, as described in the literature. The distribution of the molecular type patterns suggests that the population of M. tuberculosis complex strains isolated from Spanish wild ungulates is spatially structured despite the lack of important geographical barriers and despite the increasingly frequent wildlife translocations. Red deer and the European wild boar can share the same molecular types in localities in which the M. tuberculosis complex was isolated from both species. Strains of bovine and caprine origin do circulate in the same local wildlife populations. Six out of 11 spoligotypes were similar to types described in human cases. The isolation of TB strains in fenced estates from wild animals that have not had contact with domestic livestock for at least the past two decades, strongly suggests that the M. tuberculosis complex is able to survive in these populations. Therefore, wildlife including cervids and the wild boar need to be considered in the epidemiology and control of tuberculosis.     

The effect of combining linseed oil and sesamin on the fatty acid composition in white muscle and on expression of lipid-related genes in white muscle and liver of rainbow trout (Oncorhynchus mykiss)

Sesamin (S) is a known lipid modulator and has been shown to increase the conversion of α-linolenic acid (ALA) to docosahexaenoic acid in rainbow trout (Oncorhynchus mykiss) fed vegetable oil mixtures including linseed oil. In this study, we evaluated the effects of S supplementation in linseed oil-based diets, content of α- and γ-tocopherols, fatty acid (FA) composition, as well as the gene expression of lipid-related genes. Fish with an average weight of 36.5 g were fed different combinations of commercial linseed oil (LO), purified linseed oil triacylglycerols (TAG) with polar fraction removed and a mixed linseed-sunflower oil (6:4 v/v) (MO). S was added at 0.58 g 100^?1g feed and fed to the fish for a period of 58 days. Expression of PPARα was downregulated in white muscle of fish fed S containing diets (P < 0.05). The expression of PPARβ1A was not affected by S supplementation except where TAG oil was used. The expression of PPARβ1A declined significantly in TAG + S fed group (P < 0.05), which indicates that some minor compounds in linseed oil might suppress the effect of S on the expression of PPARβ1A. The expression of PPARγ(long) declined in LO + S and MO + S fed group (P < 0.05). The β-oxidation-related genes CPT1 and ACO were upregulated by vegetable oils compared to fish oil. S decreased percentage of ALA in white muscle of fish fed LO + S (P < 0.05). The increased desaturation index and the decreased ALA levels suggest that S may increase the biosynthesis of highly unsaturated FA in rainbow trout.     

Improving weaning strategies for Senegalese sole: effects of body weight and digestive capacity

To optimize Senegalese sole‐weaning strategies, three experiments were performed. The first trial tested four weaning strategies with a 10 mg sole. Artemia‐fed sole grew threefold less than fish fed an inert diet. Sudden weaning (abrupt change from Artemia to inert diet) and weaning with co‐feeding produced larger sole than did a late weaning treatment; delayed weaning negatively affected fish growth. In the second experiment, the digestive capacity of early‐weaned 1, 2 and 4 mg sole was investigated. The highest growth was observed in sole weaned at 4 mg. Digestive enzyme profiles suggest that sole have an adaptation period to inert diets, with reduced feed intake. This adaptation period is inversely proportional to post‐larvae weight. The third experiment examined weaning with co‐feeding at different weights (2, 5 and 11 mg). These studies demonstrate that sole of 5–10 mg can be weaned, with high survival rates. On the basis of the digestive enzyme profiles, the early introduction of inert diets in co‐feeding with Artemia seems to affect intestinal processes in smaller postlarvae. This study also suggests that trypsin and alkaline phosphatase may be used as indicators of nutritional status in sole of <5 mg.     

Influence of dietary phospholipids on early ontogenesis of fish

The aim of this paper is to provide explanations of how dietary phospholipid (PL) globally improves fish larval development, including growth and survival, digestive functions and skeletal development, and to propose optimal PL levels and sources in fish larval diets. Dietary incorporation of 8–12% PL related to dry matter (d.m.) promotes growth and enhanced survival in various species. Marine source PL, incorporating highly unsaturated fatty acids, was most efficient than soybean lecithin. This beneficial effect was explained by an enhancement in digestive functions, assessed by digestive enzyme activities and histomorphology. Nevertheless, 1.5–2.5% highly unsaturated fatty acids related to diet d.m. supplied by PL improved growth, survival and skeletal development, while 5% induced different skeletal deformities. The high incidence of deformities was associated with the down-regulation of genes involved in development, such as RXRα, RARα, RARβ and BMP-4, observed in the early stages in larvae fed a high highly unsaturated fatty acids level.     

Diet Supplementation with Fish-Derived Extracts Suppresses Diabetes and Modulates Intestinal Microbiome in a Murine Model of Diet-Induced Obesity

Metabolic syndrome-related diseases affect millions of people worldwide. It is well established that changes in nutritional habits and lifestyle can improve or prevent metabolic-related pathologies such as type-2 diabetes and obesity. Previous reports have shown that nutritional supplements have the capacity to limit glucose intolerance and suppress diabetes development. In this study, we investigated the effect of dietary supplementation with fish-derived extracts on obesity and type 2 diabetes and their impact on gut microbial composition. We showed that nutritional supplements containing Fish Complex (FC), Fish Complex combined with Cod Powder (FC + CP), or Cod Powder combined with Collagen (CP + C) improved glucose intolerance, independent of abdominal fat accumulation, in a mouse model of diet-induced obesity and type 2 diabetes. In addition, collagen-containing supplements distinctly modulate the gut microbiome in high-fat induced obesity in mice. Our results suggest that fish-derived supplements suppress diet-induced type 2 diabetes, which may be partly mediated through changes in the gut microbiome. Thus, fish-derived supplements and particularly the ones containing fish collagen have potential beneficial properties as dietary supplements in managing type 2 diabetes and metabolic syndrome via modulation of the gut microbiome.     

Validity tests of the mixing-length theory of deep convection

The construction of solar or stellar models is hindered by the difficulty of computing, with sufficient accuracy, the convective fluxes in unstable regions. Although the mixing-length theory of convection has been used for more than three decades, its validity has neither been tested by experiment nor verified by computation. This report presents the results of a three-dimensional numerical simulation of deep and efficient convection that support two conclusions: (i) the basic picture proposed by the mixing-length theory is physically valid-the vertical correlation of the motion of fluid elements is proportional to the pressure scale height; and (ii) some dynamical variables, including the convective flux, can be approximately computed from the structure of the stratification with mixing-length approximations.     

Risk factors for canine leishmaniasis in an endemic Mediterranean region

Human visceral leishmaniasis is an emergent/re-emergent parasitic zoonotic disease in Europe caused by Leishmania infantum, with domestic dog as its main reservoir host. This study presents the results of a canine epidemiological survey in a mediterranean region where human and canine leishmaniasis (CanL) are endemic - Portugal. The main goal was to identify risk factors, which can be relevant for Leishmania infection control. The national survey was carried out in January 2009 with a screening of 3974 dogs from all 18 districts of mainland Portugal. Direct Agglutination Test was used for the detection of anti-Leishmania antibodies in canine blood. An overall CanL true prevalence of 6.31% was observed. Apparent prevalence at district level ranged from 0.88% to 16.16%, with the highest prevalence in the interior regions. Identified risk factors for positivity were: dogs of 2 years and older (adjusted odds ratio OR=5.39); spending exclusively/most of the time outdoors (OR=2.51); origin from the interior of Portugal in comparison to littoral/coast districts (OR=2.51); not having long fur (OR=2.03); and being pure exotic (OR=1.67). The results confirm the leishmaniasis endemicity in Portugal and the dynamic character of prevalence as new foci emerged and old foci lost their importance. The dog's age, fur size, district and living outdoors as opposed to indoors were more important than dog breeds and insecticide treatment in the transmission of Leishmania infection. The future of CanL prevention and control rely on an integrated approach involving veterinarians, dog owners and health authorities in order to reduce the canine infection risk and consequently, the human zoonotic visceral leishmaniasis.     

Reproductive performance in sows in relation to Japanese Encephalitis Virus seropositivity in an endemic area

Japanese Encephalitis Virus (JEV) is considered an important reproductive pathogen in pigs. Most studies of the reproductive impact of JEV have been conducted in areas where the disease occurs in seasonal epidemics. In this study, the associations between seropositivity for JEV, measured with an IgG ELISA, and the number of piglets born alive and stillborn were investigated in a tropical area endemic for JEV in Vietnam. Sixty percent of sows from four farms in the Mekong delta of Vietnam were seropositive to JEV and the Odds Ratio for a sow being infected was highest (6.4) in sows above 3.5 years (95% confidence interval 2.2–18.3). There was an association between increasing Optical Density (OD) values from the ELISA and the number of stillborn piglets in sows less than 1.5 years, but no effect of seropositivity could be shown when all sows were studied. OD values had an effect (p = 0.04) on the number of piglets born alive in the statistical analysis only when interacting with the effect of the breeds. An increase in mean OD value of the herd was correlated (p < 0.0001) with an increase in the number of piglets born alive. In this study, there was evidence of a negative association between seropositivity for JEV and the reproductive performance only in sows less than 1.5 years in endemic areas. This could be explained by a year-round infection with the virus, which would lead to immunity in many gilts before their first pregnancy. This, in turn, may imply that JEV infection in pigs is of minor importance for the reproductive performance in endemic areas.