A practical approach on boar sperm cryodamage. Morphofunctional and immunocytochemical study of cryopreserved boar sperm intended for use in artificial insemination

L'ús d'esperma criopreservada en la inseminació artificial (IA) d'espècies d'interès productiu permet un major control sanitari i la creació de bancs de germoplasma d'alt valor genètic, entre d'altres avantatges. En el mercat porcí la major part de les inseminacions són encara realitzades amb semen refrigerat degut a l'èxit de l'aplicació de diluents de llarga durada i també a causa de la sensibilitat de l'esperma porcina a la criopreservació. Malgrat que aquesta sensibilitat ve donada per característiques particulars de la fisiologia espermàtica en l'espècie, algunes ejaculacions mantenen els paràmetres de qualitat espermàtica després de la criopreservació (ejaculacions amb bona "congelabilitat", GFEs) enfront d'altres que no sobreviuen al procés (ejaculacions amb mala "congelabilitat", PFEs). El primer objectiu de l'estudi va ser comparar ambdós grups en termes de fertilitat in vivo. El segon objectiu va ser testar l'eficiència de la inseminació postcervical (post-CAI) amb l'esperma criopreservada. El tercer objectiu va ser buscar predictors de la congelabilitat de les ejaculacions, tant en les GFEs com en les PFEs i en tres passos del procés de criopreservació (a 17ºC, a 5ºC i a 240 min postdescongelació). Aquest objectiu es va dur a terme mitjançant l'avaluació de paràmetres convencionals de qualitat espermàtica i a través de l'estudi de la localització i la reactivitat sota el microscopi de tres proteïnes (GLUT3, HSP90AA1 i Cu/ZnSOD) relacionades amb la fisiologia espermàtica i amb possibles rols en la congelabilitat. El quart objectiu va ser quantificar l'expressió de les tres proteïnes per transferència western, tant en espermatozoides d'ejaculacions GFEs com en els d'ejaculacions PFEs i en els tres passos abans esmentats, per tal de determinar el seu potencial com a predictores de la congelabilitat. Pel primer i el segon objectiu, 86 truges van ser inseminades per post-CAI amb 26 ejaculacions de mascles Piétrain dividides en una porció refrigerada a 17ºC (tractament control) i una porció criopreservada, ambdues porcions classificades alhora com a GFEs o PFEs. Els resultats més rellevants van demostrar que les probabilitats d'embaràs eren dues vegades menors en inseminacions amb esperma criopreservada d'ejaculacions PFEs (P < 0.05) que en inseminacions amb esperma criopreservada d'ejaculacions GFEs, fet que indica que les ejaculacions amb percentatges elevats d'espermatozoides mòbils progressius i d'integritat de membrana (per sobre del 40% en les GFEs) són més favorables a provocar embarassos que no pas aquelles ejaculacions amb una pobra funció espermàtica in vitro (PFEs). Ni el nombre de truges que van donar a llum, ni la quantitat de garrins, ni el risc de reflux espermàtic van ser significativament diferents entre les inseminacions amb esperma criopreservada d'ejaculacions GFEs i les inseminacions control amb semen refrigerat, la qual cosa demostra la bona aplicabilitat de la inseminació post-CAI amb l'esperma criopreservada. Finalment, pel tercer i quart objectius van ser criopreservades 29 i 11 ejaculacions de mascles Piétrain, respectivament. Dos paràmetres cinètics espermàtics, la linealitat (LIN) i la rectitud (STR), van mostrar una hiperactivació de la mobilitat superior en les ejaculacions PFEs que en les GFEs després de 30 min a 5ºC durant la criopreservació. A més, la combinació d'ambdós paràmetres va donar una fiabilitat propera al 72% en la predicció de la congelabilitat de les ejaculacions porcines. Tot i que no va ser possible predir la congelabilitat mitjançant l'avaluació de les tres proteïnes al microscopi, els resultats de transferència western van revelar diferències en l'expressió de la HSP90AA1 en l'esperma a 17ºC, molt possiblement relacionades amb la millor supervivència a la criopreservació dels espermatozoides d'ejaculacions GFEs. Aquests resultats suggereixen que la promoció de la criopreservació d'esperma porcina per la seva aplicació en IA passa pel desenvolupament de tests per la predicció de la congelabilitat en semen refrigerat.

The role of fungi and bacteria on the organic matter decomposition process in streams: interaction and relevance in biofilms

L'objectiu d'aquest estudi és el d'investigar sobre l'ús de matèria orgànica per part dels fongs i bacteris que colonitzen diferents substrats bentònics en rius Mediterranis i analitzar l'efecte dels factors ambientals i antròpics sobre l'estabilitat estructural i funcional de les comunitats del biofilm. La metodologia emprada en aquest estudi consisteix en: i) anàlisi de la biomassa bacteriana i fúngica, ii) anàlisi de la composició de les comunitats bentòniques (identificació d'hifomicets aquàtics i anàlisi del 16S rDNA bacterià), i iii) anàlisi de l'activitat enzimàtica extracel·lular relacionada amb el reciclatge de matèria orgànica en rius.

Estudio del impacto ambiental del uso del bagazo como fuente de energía en centrales azucareros en Cuba. Estudio de caso "Melanio Hernández"

This work was carried out to study the environmental impacts produced by power generation from biomass (bagasse) in sugar mills in Cuba. For this purpose, with the collaboration of the Center for Energy and Industrial Processes (CEEPI), the University Center of Sancti Spiritus and using different research methods and techniques, conducted an environmental survey of the area. Gaseous emissions were characterized and the suspended solid particles, allowing knowing that these concentrations do not exceed the maximum emission limit set by the cubana Standard. In addition, the dispersion model applied DISPER allowed us to obtain information in crisis conditions of air emissions from sugar mill and distillery associated and concluded that emissions from the distillery are the pollutants that contribute more the atmosphere. The correlating emissions with respiratory diseases, (acute respiratory infections or subacute (IRA) and ASMA), concurrent Asthma Crisis (CAB) is the most affected. The calculated costs associated in these diseases, amounting to $ 119 599.23 per year. In order to minimize the negative alternatives are proposed to be implemented in industry and community.

Deteção e Quantificação Precoce de Clostridium perfringens em Frangos de Crescimento Rápido e de Plumagem Branca na Região de Lisboa e Vale do Tejo

Clostridium perfringens é uma bactéria anaeróbia Gram positiva, formadora de esporos e produtora de toxinas capazes de causar um amplo espectro de doenças em humanos e animais. Em frangos de crescimento rápido e de plumagem branca pode causar lesões e manifestações clínicas severas como enterite necrótica aviária (ENA), associada a uma baixa eficiência produtiva e avultadas perdas económicas. Neste estudo pretendeu-se avaliar a utilização de um teste de ensaio imunocromatográfico de fluxo lateral, o Clostridium FirstTestTM, para deteção e quantificação precoce de C. perfringens em frangos de crescimento rápido e plumagem branca e posterior relação entre a presença do agente e as características dos bandos (peso médio à chegada, idade dos bandos à amostragem), fatores ambientais (densidade populacional, temperatura ambiente, humidade da cama) e os indicadores de produção (ganho médio diário, Índice de Conversão Alimentar e percentagem de mortalidade). Para tal, foram analisadas amostras fecais de trinta bandos, em dezoito explorações integradas, na Região de Lisboa e Vale do Tejo. De acordo com a classificação do Clostridium FirstTestTM, dos trinta bandos amostrados entre o décimo primeiro e o décimo quinto dia de vida, 30 % foram classificados como “Positivo” (n=9) e 10 % foram classificados como “Muito Positivo” (n=3); apresentando concentrações médias de C. perfringens de 0,1322 ng/ml e 0,3267 ng/ml, respectivamente. Os restantes bandos, 60% (n=18), foram considerados “Normal” e apresentaram concentrações médias de C. perfringens de 0,0283 ng/ml. As amostras fecais dos bandos classificados de “Positivo” e “Muito Positivo” foram posteriormente sujeitas a análise microbiológica apresentando ambos os grupos unidades formadoras de colónias (UFC), identificadas como C. perfringens. Verificou-se que não existe relação entre os resultados do Clostridium FirstTestTM e as características dos bandos, os fatores ambientais e os indicadores de produção. Verificou-se uma diminuição dos níveis de C. perfringens nos bandos sujeitos a tratamento.

Ovenbird (Seiurus aurocapilla) Territory Placement Near Seismic Lines is Influenced by Forest Regeneration and Conspecific Density

The boreal forest of western Canada is being dissected by seismic lines used for oil and gas exploration. The vast amount of edge being created is leading to concerns that core habitat will be reduced for forest interior species for extended periods of time. The Ovenbird (Seiurus aurocapilla) is a boreal songbird known to be sensitive to newly created seismic lines because it does not include newly cut lines within its territory. We examined multiple hypotheses to explain potential mechanisms causing this behavior by mapping Ovenbird territories near lines with varying states of vegetation regeneration. The best model to explain line exclusion behavior included the number of neighboring conspecifics, the amount of bare ground, leaf-litter depth, and canopy closure. Ovenbirds exclude recently cut seismic lines from their territories because of lack of protective cover (lower tree and shrub cover) and because of reduced food resources due to large areas of bare ground. Food reduction and perceived predation risk effects seem to be mitigated once leaf litter (depth and extent of cover) and woody vegetation cover are restored to forest interior levels. However, as conspecific density increases, lines are more likely to be used as landmarks to demarcate territorial boundaries, even when woody vegetation cover and leaf litter are restored. This behavior can reduce territory density near seismic lines by changing the spatial distribution of territories. Landmark effects are longer lasting than the effects from reduced food or perceived predation risk because canopy height and tree density take >40 years to recover to forest interior levels. Mitigation of seismic line impacts on Ovenbirds should focus on restoring forest cover as quickly as possible after line cutting.

The release of silicon from amorphous silica and rice straw in Sri Lankan soils

Silicon release from rice straw and amorphous silica when shaken in solution with five Sri Lankan soils was studied indirectly using sorption isotherms and changes in concentration and directly using straw in dialysis bags examined using electron microscopy. The aim was to further our understanding of the processes and factors affecting the release of straw-Si in soils and its availability to rice. The soils (alfisols and ultisols) shaken with 0.1 M NaCl (5 g per 125 mL for 250 days) produced concentrations of 1 - 4 mg L-1 of monosilicic acid-Si. Amorphous silica added to these suspensions (36.5 mg, containing 17 mg Si) raised the concentrations to 20 - 40 mg L-1, and added rice straw (0.5 g, containing 17 mg Si) gave 10 - 25 mg L-1. Sorption isotherms (7 days equilibrations) were used to calculate from the concentrations the amounts of Si released ( 24 - 38% and 8 - 21%, respectively). Both materials gave about 40 mg L-1 of monosilicic acid-Si plus 30 mg L-1 of disilicic acid-Si when shaken in solution alone (5 g per 125 mL). Straw in dialysis bags ( 0.5 g per 25 mL in 0.1 M NaCl) was shaken in soil suspension ( 5 g per 100 mL) for 60 days. Similar concentrations and releases were measured to those obtained above. About one fifth of the mass of straw was lost by decomposition in the first 15 days. A chloroform treatment prevented decomposition, but Si release was unaffected. Disintegration continued throughout the experiments, with phytoliths being exposed and dissolved. Compared to the rate of release from straw into solution without soil, the release of Si into soil suspensions was increased during the first 20 days by adsorption on the soil, but was then reduced probably through the effect of Fe and Al on the phytolith surfaces. The extent of this blocking effect varied between soils and was not simply related to soil pH.

Liming upland grassland: the effects on earthworm communities and the chemical characteristics of carbon in casts

Different earthworm species have different tolerances of acid soil conditions, and the application of lime to upland grassland to improve the grazing quality may therefore alter the size and diversity of the earthworm community. Altering soil properties may also affect the chemical characteristics of organic C in earthworm casts. We surveyed the earthworm community of an upland grassland in southern Scotland at the outset of annual lime applications, and after 3 years, and used C-13 nuclear magnetic resonance (NMR) spectroscopy to assess the distribution of C between different functional groups in the organic matter. In addition, soil was incubated for 8 weeks with several earthworm species in the presence or absence of lime, and the earthworm casts were subsequently analysed by C-13 NMR spectroscopy. Liming did not significantly affect earthworm abundance or species diversity, but it did affect the chemical composition of the casts. Casts from earthworms incubated in unlimed soil had greater ratios of alkyl-C to O-alkyl-C, indicative of more decomposed, recalcitrant C, and spectra from litter-feeding species had the greatest intensities of O-alkyl-C signals. In limed soil, the largest O-alkyl-C signal intensities were not restricted to litter-feeding species, indicating an increase in the quality of organic matter ingested by geophagous species.

Modeling the mechanisms that control in-stream dissolved organic carbon dynamics in upland and forested catchments

[1] We present a new, process-based model of soil and stream water dissolved organic carbon (DOC): the Integrated Catchments Model for Carbon (INCA-C). INCA-C is the first model of DOC cycling to explicitly include effects of different land cover types, hydrological flow paths, in-soil carbon biogeochemistry, and surface water processes on in-stream DOC concentrations. It can be calibrated using only routinely available monitoring data. INCA-C simulates daily DOC concentrations over a period of years to decades. Sources, sinks, and transformation of solid and dissolved organic carbon in peat and forest soils, wetlands, and streams as well as organic carbon mineralization in stream waters are modeled. INCA-C is designed to be applied to natural and seminatural forested and peat-dominated catchments in boreal and temperate regions. Simulations at two forested catchments showed that seasonal and interannual patterns of DOC concentration could be modeled using climate-related parameters alone. A sensitivity analysis showed that model predictions were dependent on the mass of organic carbon in the soil and that in-soil process rates were dependent on soil moisture status. Sensitive rate coefficients in the model included those for organic carbon sorption and desorption and DOC mineralization in the soil. The model was also sensitive to the amount of litter fall. Our results show the importance of climate variability in controlling surface water DOC concentrations and suggest the need for further research on the mechanisms controlling production and consumption of DOC in soils.

The importance of precision in sampling sludges, biowastes and treated soils in a regulatory framework

As part of the European Commission (EC)'s revision of the Sewage Sludge Directive and the development of a Biowaste Directive, there was recognition of the difficulty of comparing data from Member States (MSs) because of differences in sampling and analytical procedures. The 'HORIZONTAL' initiative, funded by the EC and MSs, seeks to address these differences in approach and to produce standardised procedures in the form of CEN standards. This article is a preliminary investigation into aspects of the sampling of biosolids, composts and soils to which there is a history of biosolid application. The article provides information on the measurement uncertainty associated with sampling from heaps, large bags and pipes and soils in the landscape under a limited set of conditions, using sampling approaches in space and time and sample numbers based on procedures widely used in the relevant industries and when sampling similar materials. These preliminary results suggest that considerably more information is required before the appropriate sample design, optimum number of samples, number of samples comprising a composite, and temporal and spatial frequency of sampling might be recommended to achieve consistent results of a high level of precision and confidence. (C) 2004 Elsevier Ltd. All rights reserved.

Phosphorus sorption and availability in soils amended with animal manures and sewage sludge

Soils that receive large applications of animal wastes and sewage sludge are vulnerable to releasing environmentally significant concentrations of dissolved P available to subsurface flow owing to the gradual saturation of the soil's P sorption capacity. This study evaluated P sorption (calculated from Langmuir isotherms) and availability of P (as CaCl2-P and resin P) in soils incubated for 20 d with poultry litter, poultry manure, cattle slurry, municipal sewage sludge, or KH2PO4, added on a P-equivalent basis (100 mg P kg(-1)). All the P sources had a marked negative effect on P sorption and a positive effect on P availability in all soils. In the cattle slurry- and KH2PO4- treated soils, the decreases in P sorption maximum (19-66%) and binding energy (25-89%) were consistently larger than the corresponding decreases (7-41% and 11-30%) in poultry litter-, poultry manure-, and sewage sludge-treated soils. The effects of cattle slurry and KH2PO4 on P availability were, in most cases, larger than those of the other P sources. In the poultry litter, poultry manure, and sewage sludge treatments, the increase in soil solution P was inversely related (R-2 = 0.75) to the input of Ca from these relatively high Ca (13.5-42 g kg(-1)) sources. Correlation analyses implied that the magnitude of the changes in P sorption and availability was not related to the water-extractable P content of the P sources. Future research on the sustainable application of organic wastes to agricultural soils needs to consider the non-P- as well as P-containing components of the waste.

Differences in phosphorus retention and release in soils amended with animal manures and sewage sludge

Excessive levels of P in agricultural soils pose a threat to local water quality. This study evaluated (i) time-dependent changes in soil P sorption (expressed as a phosphorus sorption index, PSI) and P availability (as resin P) during incubation (100 d) with poultry litter, cattle slurry, sewage sludge, or KH2PO4, added on a P-equivalent basis (100 mg P kg(-1)), and (ii) the subsequent kinetics of P release, measured by repeated extractions with a mixed cation-anion exchange resin. Soil exchangeable Ca and ammonium oxalate-extractable Fe and Al were also determined at 100 d of incubation. The small decrease in P sorption in the litter and sludge treatments (25%), compared with that in the slurry and KH2PO4 treatments (52%) between 20 and 100 d of incubation was attributed partly to the formation of new adsorption sites for P. Subsequent P release was described by a power equation: Resin P = a(extraction number)(b), where the constants a and b represent resin P obtained with a single extraction and the rate of P release per resin extraction, respectively. On average, the rate of P release decreased in the order: KH2PO4 and slurry > litter > sludge, and was inversely related to exchangeable Ca content of the incubated soils (R-2 = 0.57). The slower rates of P release in the litter and sludge treatments (P < 0.001) are attributed to the large values for exchangeable Ca (1050-2640 and 1070-2710 mg kg(-1), respectively) in these amended soils. Future research concerned with short-term declines in environmentally harmful levels of P in recently amended soils should consider the differential effects of the amendments on soil P dynamics.

The release of silicon from amorphous silica and rice straw in Sri Lankan soils

Silicon release from rice straw and amorphous silica when shaken in solution with five Sri Lankan soils was studied indirectly using sorption isotherms and changes in concentration and directly using straw in dialysis bags examined using electron microscopy. The aim was to further our understanding of the processes and factors affecting the release of straw-Si in soils and its availability to rice. The soils (alfisols and ultisols) shaken with 0.1 M NaCl (5 g per 125 mL for 250 days) produced concentrations of 1 - 4 mg L-1 of monosilicic acid-Si. Amorphous silica added to these suspensions (36.5 mg, containing 17 mg Si) raised the concentrations to 20 - 40 mg L-1, and added rice straw (0.5 g, containing 17 mg Si) gave 10 - 25 mg L-1. Sorption isotherms (7 days equilibrations) were used to calculate from the concentrations the amounts of Si released ( 24 - 38% and 8 - 21%, respectively). Both materials gave about 40 mg L-1 of monosilicic acid-Si plus 30 mg L-1 of disilicic acid-Si when shaken in solution alone (5 g per 125 mL). Straw in dialysis bags ( 0.5 g per 25 mL in 0.1 M NaCl) was shaken in soil suspension ( 5 g per 100 mL) for 60 days. Similar concentrations and releases were measured to those obtained above. About one fifth of the mass of straw was lost by decomposition in the first 15 days. A chloroform treatment prevented decomposition, but Si release was unaffected. Disintegration continued throughout the experiments, with phytoliths being exposed and dissolved. Compared to the rate of release from straw into solution without soil, the release of Si into soil suspensions was increased during the first 20 days by adsorption on the soil, but was then reduced probably through the effect of Fe and Al on the phytolith surfaces. The extent of this blocking effect varied between soils and was not simply related to soil pH.

A new Snow-SVAT to simulate the accumulation and ablation of seasonal snow cover beneath a forest canopy

A new snow-soil-vegetation-atmosphere transfer (Snow-SVAT) scheme, which simulates the accumulation and ablation of the snow cover beneath a forest canopy, is presented. The model was formulated by coupling a canopy optical and thermal radiation model to a physically-based multi-layer snow model. This canopy radiation model is physically-based yet requires few parameters, so can be used when extensive in-situ field measurements are not available. Other forest effects such as the reduction of wind speed, interception of snow on the canopy and the deposition of litter were incorporated within this combined model, SNOWCAN, which was tested with data taken as part of the Boreal Ecosystem-Atmosphere Study (BOREAS) international collaborative experiment. Snow depths beneath four different canopy types and at an open site were simulated. Agreement between observed and simulated snow depths was generally good, with correlation coefficients ranging between r^2=0.94 and r^2=0.98 for all sites where automatic measurements were available. However, the simulated date of total snowpack ablation generally occurred later than the observed date. A comparison between simulated solar radiation and limited measurements of sub-canopy radiation at one site indicates that the model simulates the sub-canopy downwelling solar radiation early in the season to within measurement uncertainty.

Effect of dietary supplementation of different oils during the first or second half of pregnancy on the glucose tolerance of the sow

Poor glucose tolerance may be an under-researched contributory factor in the high (10% to 20%) pre-weaning mortality rate observed in pigs. Insulin resistance commences at around week 12 of gestation in the sow, although there are conflicting reports in the literature about the extent to which insulin resistance is modulated by maternal diet. The aim of the study was to determine the effects of supplementing the maternal diet with different dietary oils during either the first half or the second half of gestation on the glucose tolerance of the sow. Sows were offered the control (C: n = 5) diet as pellets or the C diet plus 10% extra energy (h = 16 per group) derived from either. (i) extra pellets; (ii) palm oil; (iii) olive oil; (iv) sunflower oil; or (v) fish oil. Experimental diets were fed during either the first (G1) or second (G2) half of gestation. A glucose tolerance test (GTT) was conducted on day 108 of gestation by administering 0.5g/kg glucose i.v. Blood samples were taken every 5 to 10 min for 90 min post administration. The change in body weight and backfat thickness during gestation was similar but both type and timing of dietary supplementation influenced litter size and weight. With the exception of the sunflower oil group, supplementing the maternal diet in G1 resulted in larger and heavier litters, particularly in mothers offered palm oil. Basal blood glucose concentrations tended to be more elevated in G1 than G2 groups, whilst plasma insulin concentrations were similar Following a GTT, the adjusted area under the curve was greater in G1 compared to G2 sows, despite no differences in glucose clearance. Maternal diet appeared to influence the relationship between glucose curve characteristics following a GTT and litter outcome. In conclusion, the degree of insulin sensitivity can be altered by both the period during which maternal nutritional supplementation is offered and the fatty acid profile of the diet.

Intergenerational effects of birth weight on glucose tolerance and reproductive performance

Women who were themselves small-for-gestational age (SGA) are at a greater risk of adulthood diseases such as non-insulin-dependent diabetes mellitus (NIDDM), and twice at risk of having an SGA baby themselves. The aim of this study was to examine the intergenerational pig. Low (L) and normal (N) birth weight female piglets were followed throughout their first pregnancy (generation 1 (0)). After they had given birth, the growth and development of the lightest (I) and heaviest (n) female piglet from each litter were monitored until approximately 5 months of age (generation 2 (G2)). A glucose tolerance test (GTT) was conducted on G1 pig at similar to 6 months of age and again during late pregnancy; a GTT was also conducted on G2 pigs at similar to 4 months of age. G1 L offspring exhibited impaired glucose metabolism in later life compared to their G1 N sibling but in the next generation a similar scenario was only observed between I and n offspring born to G1 L mothers. Despite G1 L mothers showing greater glucose intolerance in late pregnancy and a decreased litter size, average piglet birth weight was reduced and there was also a large variation in litter weight; this suggests that they were, to some extent, prioritising their nutrient intake towards themselves rather than promoting their reproductive performance. There were numerous relationships between body shape at birth and glucose curve characteristics in later life, which can, to some extent, be used to predict neonatal outcome. In conclusion, intergenerational effects are partly seen in the pig. It is likely that some of the intergenerational influences may be masked due to the pig being a litter-bearing species.