The use of seaweed from the Galician coast as a mineral supplement in organic dairy cattle

This study was designed to assess the value of seaweeds from the Galician coast as a source of minerals (especially iodine (I) but also other micro-minerals) in organic dairy cattle. It was conducted in an organic dairy farm in the Lugo province that typically represents the organic milk production in NW Spain. The animal’s diet consisted mainly of local forage (at pasture or as hay and silage in the winter) and 5 kg of purchased concentrate/day per animal (representing 23.5% of feed intake). Based on the mineral composition of the diet, the physiological requirements and the EU maximum authorised levels in feed, a supplement composed by Sea Lettuce (Ulva rigida) (as flakes, 80%), Japanese Wireweed (Sargasum muticum) (flakes, 17.5%) and Furbelows (Saccorhiza polyschides) (powder, 2.5%) was formulated to give 100 g/animal per day. Sixteen Holstein Friesian lactating cows were randomly selected and assigned to the control (n=8) and algae-supplemented groups (n=8). Both groups had exactly the same feeding and management with the exception of the algae supplement, which was mixed with the concentrate feed and given to the animals at their morning milking for 10 weeks. Heparinised blood (for plasma analysis) and milk samples were collected at 2-week intervals and analysed for toxic and trace element concentrations by inductively coupled plasma-mass spectrometry or inductively coupled plasma-optical emission spectrometry. The algae supplement significantly improved the animals’ mineral status, particularly I and selenium that were low on the farm. However, the effect of the algae supplement on the molybdenum status in cattle needs further investigation because of its great relevance on copper metabolism in ruminants. The I supply deserves special attention, since this element is at a very high concentration in brown-algae species and it is excreted in the milk proportionally to its concentration in plasma concentrations (mean±s.e. in the algae-supplemented and control groups were 268±54 and 180±42 µg/l, respectively)This work was supported by the Spanish Government (projectcode AGL2010-21026) and Centro Tecnológico Agroalimentario de Lugo (CETAL)S

Dairy cow nutrition in organic farming systems. Comparison with the conventional system

The energy supplied by the high-forage diets used in organic farming may be insufficient to meet the requirements of dairy cattle. However, few studies have considered this problem. The present study aimed to analyze the composition of the diets and the nutritional status (focusing on the energy–protein balance of the diets) of dairy cattle reared on organic farms in northern Spain, which are similar to other organic farming systems in temperate regions. Exhaustive information about diets was obtained from organic (ORG) and representative conventional grazing (GRZ) and conventional no-grazing (CNG) farms. Samples of feed from the respective farms were analyzed to determine the composition. Overall, the diets used on the ORG farms were very different from those used on the CNG farms, although the difference was not as evident for GRZ. The CNG farms were characterized by a higher total dry matter intake with a high proportion of concentrate feed, maize silage and forage silage. By contrast, on ORG and GRZ farms, the forage, pasture and fibre intake were the most important variables. The ration used on ORG farms contained a significantly higher percentage of ADF and lower organic matter (OM) content than the rations used in both of the conventional farming systems, indicating that the diets in the former were less digestible. Although the protein concentration in the diets used on the grazing farms (ORG and GRZ) was higher than those used on CNG farms, the protein intake was similar. The results indicated an imbalance between energy and protein due to the low level of energy provided by the ORG diets, suggesting that more microbial protein could be synthesized from the available rumen-degraded dietary nitrogen if rumen-fermentable OM was not limiting. The imbalance between energy and protein led to a reduced amount of total digestible protein reaching the intestine and a lower milk yield per kilogram of CP intake on the ORG farms. In order to improve the protein use efficiency and consequently to reduce the loss of nitrogen to the environment, organic farming should aim to increase the energy content of cattle diets by improving forage quality and formulating rations with more balanced combinations of forage and grainThis study was supported by the Spanish Government (project code AGL2010-21026) and Centro Tecnológico Agroalimentario de Lugo (CETAL). I. Orjales is in receipt of a FPU fellowship (Ref. FPU14/01473) from the Spanish Ministry of Education, Culture and SportsS

Histochemistry evaluation of the oxidative stress and the antioxidant status in Cu-supplemented cattle

The aim of this paper is to evaluate at a histopathological level the effect of the most commonly used copper (Cu) supplementation (15 mg/kg dry matter (DM)) in the liver of intensively reared beef cattle. This was done by a histochemistry evaluation of (i) the antioxidant capacity in the liver – by the determination of metallothioneins (MT) and superoxide dismutase (SOD) expression – as well as (ii) the possible induction of oxidative damage – by the determination of inducible nitric oxide synthase (iNOS), nitrotyrosine (NITT), malondialdehyde (MDA) and 8-oxoguanine (8-oxo) – that (iii) could increase apoptotic cell death – determined by cytochrome-c (cyto-c), caspase 1 (casp1) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Liver samples from Cu-supplemented (15 mg Cu sulphate/kg DM, n = 5) and non-supplemented calves (n = 5) that form part of other experiments to evaluate Cu status were collected at slaughter and processed for immunohistochemistry and TUNEL. MT expression was diffuse and SOD showed slight changes although without statistical significance. iNOS and NITT positive (+) cells significantly increased, mainly around the central veins in the animals from the Cu-supplemented group, whereas no differences were appreciated for the rest of the oxidative stress and apoptosis markers. Under the conditions of this study, which are the conditions of the cattle raised in intensive systems in NW Spain and also many European countries, routinely Cu supplementation increased the risk of the animals to undergo subclinical Cu toxicity, with no significant changes in the Cu storage capacity and the antioxidant defensive system evaluated by MT and SOD expression, but with a significant and important increase of oxidative damage measured by iNOS and NITT. The results of this study indicated that iNOS and NITT could be used as early markers of initial pathological changes in the liver caused by Cu supplementation in cattle, although more studies in cattle under different levels of Cu supplementation are neededThis work was supported by the Xunta de Galicia (Spain) through contract 07MRU030261PR and by a research grant María Barbeito awarded to M. García-Vaquero by the Dirección Xeral de Investigación, Desenvolvemento e Innovación from Xunta de Galicia and to FSE (Fondo Social Europeo) funds through Programa de Recursos Humanos, do Plan Galego de Investigación, Desenvolvemento e Innovación Tecnolóxica de GaliciaS

On the derived category of quasi-coherent sheaves on an Adams geometric stack

Let X be an Adams geometric stack. We show that D(Aqc(X)), its derived category of quasi-coherent sheaves, satisfies the axioms of a stable homotopy category defined by Hovey, Palmieri and Strickland in [13]. Moreover we show how this structure relates to the derived category of comodules over a Hopf algebroid that determines X.Ministerio de Ciencia e Innovación | Ref. MTM2011-26088Ministerio de Economía y Competitividad | Ref. MTM2014-59456Xunta de Galicia | Ref. GRC2013-04

A functorial formalism for quasi-coherent sheaves on a geometric stack

A geometric stack is a quasi-compact and semi-separated algebraic stack. We prove that the quasi-coherent sheaves on the small flat topology, Cartesian presheaves on the underlying category, and comodules over a Hopf algebroid associated to a presentation of a geometric stack are equivalent categories. As a consequence, we show that the category of quasi-coherent sheaves on a geometric stack is a Grothendieck category. We also associate, in a 2-functorial way, to a 1-morphism of geometric stacks, an adjunction f^∗⊣f_∗ for the corresponding categories of quasi-coherent sheaves that agrees with the classical one defined for schemes. This construction is described both geometrically in terms of the small flat site and algebraically in terms of comodules over the Hopf algebroid.Ministerio de Ciencia e Innovación | Ref. MTM2008-03465Ministerio de Ciencia e Innovación | Ref. MTM2011-26088Xunta de Galicia | Ref. GRC2013-04

Selective interaction of PEGylated polyglutamic acid nanocapsules with cancer cells in a 3D model of a metastatic lymph node

Background Metastases are the most common reason of cancer death in patients with solid tumors. Lymph nodes, once invaded by tumor cells, act as reservoirs before cancer cells spread to distant organs. To address the limited access of intravenously infused chemotherapeutics to the lymph nodes, we have developed PEGylated polyglutamic acid nanocapsules (PGA-PEG NCs), which have shown ability to reach and to accumulate in the lymphatic nodes and could therefore act as nanotransporters. Once in the lymphatics, the idea is that these nanocapsules would selectively interact with cancer cells, while avoiding non-specific interactions with immune cells and the appearance of subsequent immunotoxicity. Results The potential of the PGA-PEG NCs, with a mean size of 100 nm and a negative zeta potential, to selectively reach metastatic cancer cells, has been explored in a novel 3D model that mimics an infiltrated lymph node. Our 3D model, a co-culture of cancer cells and lymphocytes, allows performing experiments under dynamic conditions that simulate the lymphatic flow. After perfusion of the nanocarriers, we observe a selective interaction with the tumor cells. Efficacy studies manifest the need to develop specific therapies addressed to treat metastatic cells that can be in a dormant state. Conclusions We provide evidence of the ability of PGA-PEG NCs to selectively interact with the tumor cells in presence of lymphocytes, highlighting their potential in cancer therapeutics. We also state the importance of designing precise in vitro models that allow performing mechanistic assays, to efficiently develop and evaluate specific therapies to confront the formation of metastasisThe authors acknowledge financial support given by the Carlos III Health Institute (ISCIII) and European Regional Development Fund (FEDER) (CP12/03150, PIE13/00024 and PI15/00828), ERA-NET EuroNanoMed 2009 (Lymphotarg PI09/2670) and EuroNanoMed 2013 (053 NICHE). The first author also acknowledges a fellowship received from the Fundación Ramón Domínguez, Spain. Abellan-Pose also acknowledges a fellowship from the Biomedical Sciences and Health Technologies Doctoral School-University of Santiago de Compostela (Spain)S

Measuring haemolysis in cattle serum by direct UV–VIS and RGB digital image-based methods

A simple, rapid procedure is required for the routine detection and quantification of haemolysis, one of the main sources of unreliable results in serum analysis. In this study, we compared two different approaches for the rapid determination of haemolysis in cattle serum. The first consisted of estimating haemolysis via a simple direct ultraviolet–visible (UV–VIS) spectrophotometric measurement of serum samples. The second involved analysis of red, green, blue (RGB) colour data extracted from digital images of serum samples and relating the haemoglobin (Hb) content by means of both univariate (R, G, B and intensity separately) and multivariate calibrations (R, G, B and intensity jointly) using partial least squares regression and artificial neural networks. The direct UV–VIS analysis and RGB-multivariate analysis using neural network methods were both appropriate for evaluating haemolysis in serum cattle samples. The procedures displayed good accuracy (mean recoveries of 100.7 and 102.1%, respectively), adequate precision (with coefficients of variation from 0.21 to 2.68%), limit of detection (0.14 and 0.21 g L–1, respectively), and linearity of up to 10 g L–S

Evaluation of trace element status of organic dairy cattle

The present study aimed to evaluate trace mineral status of organic dairy herds in northern Spain and the sources of minerals in different types of feed. Blood samples from organic and conventional dairy cattle and feed samples from the respective farms were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of the essential trace elements (cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), iodine (I), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn)) and toxic trace elements (arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb)). Overall, no differences between organic and conventional farms were detected in serum concentrations of essential and toxic trace elements (except for higher concentrations of Cd on the organic farms), although a high level of inter-farm variation was detected in the organic systems, indicating that organic production greatly depends on the specific local conditions. The dietary concentrations of the essential trace elements I, Cu, Se and Zn were significantly higher in the conventional than in the organic systems, which can be attributed to the high concentration of these minerals in the concentrate feed. No differences in the concentrations of trace minerals were found in the other types of feed. Multivariate chemometric analysis was conducted to determine the contribution of different feed sources to the trace element status of the cattle. Concentrate samples were mainly associated with Co, Cu, I, Se and Zn (i.e. with the elements supplemented in this type of feed). However, pasture and grass silage were associated with soil-derived elements (As, Cr, Fe and Pb) which cattle may thus ingest during grazingThis study was supported by the Spanish Government (project code AGL2010-21026). Inmaculada Orjales is in receipt of a FPU fellowship (Ref. FPU14/01473) from the Spanish Ministry of Education, Culture and SportsS

The derived category of quasi-coherent sheaves and axiomatic stable homotopy

We prove in this paper that for a quasi-compact and semi-separated (non necessarily noetherian) scheme X, the derived category of quasi-coherent sheaves over X, D(A_qc(X)), is a stable homotopy category in the sense of Hovey, Palmieri and Strickland, answering a question posed by Strickland. Moreover we show that it is unital and algebraic. We also prove that for a noetherian semi-separated formal scheme X, its derived category of sheaves of modules with quasi-coherent torsion homologies D_qct(X) is a stable homotopy category. It is algebraic but if the formal scheme is not a usual scheme, it is not unital, therefore its abstract nature differs essentially from that of the derived category of a usual scheme.Comment: v2: 31 pages, some improvements in exposition; v3 updated bibliography, to appear Adv. Mat

Trace Element Levels in Serum Are Potentially Valuable Diagnostic Markers in Dogs

The objective of this study was to obtain information about the role of trace element imbalance in the pathogenesis of certain diseases in dogs and to evaluate the suitability of trace element profiling as an additional tool in the diagnosis. Serum trace element concentrations (copper, molybdenum, selenium and zinc) were measured in a cohort of healthy (control) dogs (n = 42) and dogs affected by hepatic (n = 25), gastrointestinal (n = 24), inflammatory/infection (n = 24), and renal (n = 22) diseases. These data were analyzed together with data on basic biochemical parameters (alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, creatinine, albumin, globulin, and glucose) by using chemometric techniques. The chemometric analysis revealed distinctive association patterns between trace elements and biochemical parameters for each clinical disorders. The findings provide clear evidence for the important role of trace elements in disease, particularly in relation to acute phase reactions, with serum copper providing an indirect measurement of ceruloplasmin (positive acute-phase protein) and serum selenium and zinc acting as negative acute phase reactants. Molybdenum may also be a suitable marker of incipient renal disease. Thus, the analysis of trace element profiles, by multielement techniques, in a single serum sample would be a valuable additional tool for the diagnosis of certain diseasesS