The objective of this study was to evaluate the production, consumption, and energy balance parameters of primiparous 3/4 and 7/8 Holstein × Gir (HG) dairy cows fed two diets of differing energy levels during the postpartum period. At the beginning of the study, 28 days prepartum, the average weight of both genetic groups was 498?±?12 kg and body condition score (BCS) was 3.5?±?0.05. At the end of the study, 61 days postpartum, the 3/4 HG cows had higher weight and body condition scores than the 7/8 HG (456?±?8 and 429?±?8 kg and 3.13?±?0.03 and 2.94?±?0.03 BCS for 3/4 HG and 7/8 HG, respectively). Milk from cows fed the high-energy diet had higher percentages of fat, protein, lactose, and total dry extract than cows fed the low-energy diet. Cows fed the high-energy diet had higher net energy intake (95.3?±?1.9 vs. 88.1?±?2.1 MJ/day) and higher energy balance (3.64?±?2.13 vs ??6.02?±?2.30 MJ/day). The 3/4 HG cows displayed higher energy for maintenance (33.1?±?0.4 MJ/day) than the 7/8 HG (31.5?±?0.5 MJ /day). In conclusion, although the primiparous 3/4 HG were heavier than the 7/8 HG and had a higher body condition score, no differences in milk produced up to 60 days postpartum were observed. The higher energy diet during the postpartum period increased energy balance, resulting in higher production of milk fat, protein, and lactose.
The prevalence of cancer in animals has increased significantly over the years. Mammary tumours are the most common neoplasia in dogs, in which around 50% are presented in the malignant form. Hence, the development and characterization of in vitro models for the study of canine tumours are important for the improvement of cancer diagnosis and treatment. Thus, the aim of this study was to characterize cell lines derived from canine mammary gland neoplasias which could be further used for basic and applied oncology research. Samples of canine mammary carcinomas were taken for cell culture and 2 cell lines were established and characterized in terms of cell morphology, tumourigenicity and global gene expression. Both cell lines presented spindle‐shape morphology and shown common malignant features as in vitro invasion potential and expression of epithelial and mesenchymal proteins. Also, we found gene expression patterns between the 2 cell cultures in comparison to the normal mammary gland tissue. Cells from M25 culture showed a higher invasion and in vivo tumourigenic potential, associated to the overexpression of genes involved in focal adhesion and extracellular matrix communication, such as FN1, ITGA8 and THBS2. The phenotypic characterization of these cells along with their global gene expression profile potentially determine new therapeutic targets for mammary tumours. 相似文献
Land-use/land-cover (LU/LC) dynamics is one of the main drivers of global environmental change. In the last years, aerial and satellite imagery have been increasingly used to monitor the spatial extent of changes in LU/LC, deriving relevant biophysical parameters (i.e. primary productivity, climate and habitat structure) that have clear implications in determining spatial and temporal patterns of biodiversity, landscape composition and ecosystem services.
Objectives
An innovative hierarchical modelling framework was developed in order to address the influence of nested attributes of LU/LC on community-based ecological indicators.
Methods
Founded in the principles of the spatially explicit stochastic dynamic methodology (StDM), the proposed methodological advances are supported by the added value of integrating bottom-up interactions between multi-scaled drivers.
Results
The dynamics of biophysical multi-attributes of fine-scale subsystem properties are incorporated to inform dynamic patterns at upper hierarchical levels. Since the most relevant trends associated with LU/LC changes are explicitly modelled within the StDM framework, the ecological indicators’ response can be predicted under different social-economic scenarios and site-specific management actions. A demonstrative application is described to illustrate the framework methodological steps, supporting the theoretic principles previously presented.
Conclusions
We outline the proposed multi-model framework as a promising tool to integrate relevant biophysical information to support ecosystem management and decision-making.
This study focused on the capability of two silty soils (tills) having low clay contents and CEC to retain and release two heavy metals, Pb and Cu. Samples of two non contaminated till deposits from the Eastern Townships region of Quebec, Canada, were artificially contaminated with concentrated solutions of these heavy metals. The latter were later extracted from the various geochemical phases of the soils by using the sequential extraction procedure. The results show that silty soils may have a relatively high heavy metal retention capacity due to the presence of carbonate and that this retention capacity can be comparable in magnitude to the retention capacity of certain clayey soils. This is particularly positive in the context of municipal waste disposal (landfills) in Quebec, where some old sanitary landfill sites are underlain by till deposits. A high buffering capacity is not as desirable in the case a deposit needs to undergo remediation. 相似文献
Biofouling, which occurs when certain marine species attach and accumulate in artificial submerged structures, represents a serious economic and environmental issue worldwide. The discovery of new non-toxic and eco-friendly antifouling systems to control or prevent biofouling is, therefore, a practical and urgent need. In this work, the antifouling activity of a series of 24 xanthones, with chemical similarities to natural products, was exploited. Nine (1, 2, 4, 6, 8, 16, 19, 21, and 23) of the tested xanthones presented highly significant anti-settlement responses at 50 μM against the settlement of mussel Mytilus galloprovincialis larvae and low toxicity to this macrofouling species. Xanthones 21 and 23 emerged as the most effective larval settlement inhibitors (EC50 = 7.28 and 3.57 µM, respectively). Additionally, xanthone 23 exhibited a therapeutic ratio (LC50/EC50) > 15, as required by the US Navy program attesting its suitability as natural antifouling agents. From the nine tested xanthones, none of the compounds were found to significantly inhibit the growth of the marine biofilm-forming bacterial strains tested. Xanthones 4, 6, 8, 16, 19, 21, and 23 were found to be non-toxic to the marine non-target species Artemia salina (<10% mortality at 50 μM). Insights on the antifouling mode of action of the hit xanthones 21 and 23 suggest that these two compounds affected similar molecular targets and cellular processes in mussel larvae, including that related to mussel adhesion capacity. This work exposes for the first time the relevance of C-1 aminated xanthones with a 3,4-dioxygenated pattern of substitution as new non-toxic products to prevent marine biofouling. 相似文献
1. Diversity assessments and conservation management should take into account the dynamic nature of populations and communities, particularly when they are subject to highly variable and unpredictable environmental conditions.
2. This study evaluates the inter‐annual variability in the assemblage composition (temporal turnover) of an amphibian community breeding in a highly dynamic habitat, a Mediterranean temporary pond system, during a 4‐year period.
3. A comprehensive framework is provided to evaluate temporal turnover from data of a differing nature (species richness, presence/absence and relative abundance) and, especially, to discern variation in richness (species loss) from changes in the identity or abundance of species (species replacement).
4. Results show that the pond amphibian assemblages in Doñana National Park exhibited high inter‐annual variability during the study period, both in the number of species, species identity and their relative abundance. This result provides evidence for the inadequacy of surveys conducted only in one breeding season to characterize the species assemblage associated with a given pond. Besides, it suggests that a given pond offers different breeding opportunities over time, being suitable for different species depending on the year. This alternation will contribute to the medium‐term preservation of all species in the assemblage.
Recent large fluctuations in an index of relative abundance for the silky shark in the eastern Pacific Ocean have called into question its reliability as a population indicator for management. To investigate whether these fluctuations were driven by environmental forcing rather than true changes in abundance, a Pacific‐wide approach was taken. Data collected by observers aboard purse‐seine vessels fishing in the equatorial Pacific were used to compute standardized trends in relative abundance by region, and where possible, by shark size category as a proxy for life stage. These indices were compared to the Pacific Decadal Oscillation (PDO), an index of Pacific Ocean climate variability. Correlation between silky indices and the PDO was found to differ by region and size category. The highest correlations by shark size category were for small (<90 cm total length [TL]) and medium (90–150 cm TL) sharks from the western region of the equatorial eastern Pacific (EP) and from the equatorial western Pacific. This correlation disappeared in the inshore EP. Throughout, correlations with the PDO were generally lower for large silky sharks (>150 cm TL). These results are suggestive of changes in the small and medium silky indices being driven by movement of juvenile silky sharks across the Pacific as the eastern edge of the Indo‐Pacific Warm Pool shifts location with ENSO events. Lower correlation of the PDO with large shark indices may indicate that those indices were less influenced by environmental forcing and therefore potentially less biased with respect to monitoring population trends. 相似文献