2,794 research outputs found
Resilience and Degradation in a Tropical Wetland Overgrazed by Cattle
The Pantanal, one of the largest wetlands in the world, is highly valued for its diversity of flora and fauna, and the dynamic hydrological regime, combined with heterogeneous topography, has resulted in a mosaic of diverse habitats types in terms of species and physical structure. However, the Pantanal floodplains are also important for beef cattle production due to the abundance of forage resources. Cattle prefer grazing near water bodies because these areas have high quality forage as a result of flooding regimes (Santos et al. 2002). Many wetlands go through a wet/dry cycle that is essential to maintain their productivity and function. In drier years, wetland drawdown provides optimal conditions for a diverse range of forage species, and in these conditions cattle can graze continuously leading to pasture degradation. It is therefore essential to understand the spatial and temporal dynamics of forage production and consumption.
In this study we assessed and monitored vegetation, from long-term permanent plots located at the edge of one of the pond habitats intensively grazed by cattle, in order to evaluate degradation and quantify indicators of resilience (Briske et al. 2006)
Sett Use, Density and Breeding Phenology of Badgers in Mediterranean Agro-Sylvo-Pastoral Systems
Carnivores social organization varies widely, from strongly social to solitary predators.
European badgers are facultative social carnivores that also shows a geographical variation in
social structure. These patterns derive mainly from central/west European regions, with an underrepresentation
of Mediterranean populations that face different conservation challenges, especially
regarding group composition, sett use patterns and breeding phenology. We addressed these traits
topics for a population inhabiting a Portuguese agro-silvo-pastoral system. Based on monthly
monitoring of 34 setts and continuous camera-trapping surveys of 12, we showed that setts surrounded
by diversified vegetation and located in sandy sites are more used, a pattern probably
linked to food availability and ease of sett excavation and maintenance, respectively. Badgers followed
a general pattern regarding group size (2â4 adults), but showed an intermediate population
density (0.49â0.73 badgers/km2), with values higher than those estimated for other Mediterranean
environments, but lower than for central-western populations. This, together with the breeding
(November/January) and cub emergence (1.8 cubs/sett; March/April) periods, indicates an ecological
adaptation to the landscape context, where human-related resources and mild environmental
conditions allow badger to reach higher densities than in many southern populations, and to reproduce
earlier than their northern counterparts.Understanding carnivores social structure variation is pivotal for properly addressing
conservation challenges and solutions. The European badgers is a social carnivore for
which most of the available information regarding how this species is socially organized derives
from central west populations. This article describes the group composition, den use patterns and
breeding phenology of a Mediterranean population of badgers. We showed that badger live in
low density, in relatively small groups, composed by 2â4 adult animals and ca. 2 cubs, born in
winter. These patterns, representing a variation of what was described for other populations, show
that badgers take advantage of the landscape context, where human-related resources and mild
environmental conditions allow badger to reach higher densities than in many southern populations,
and to reproduce earlier than their northern counterparts.info:eu-repo/semantics/publishedVersio
Ionizing radiation for food preservation processing: less or in excess?
The industrial use of ionizing radiations, such as gamma and electron beam (e-beam) radiation, is regulated and authorized by international organizations (EU, EFSA, IAEA, FAO, WHO) for several purposes: medical devices sterilization, materials modification, heritage preservation and food decontamination. However, there is mistrust among the general public regarding food irradiation due to the wrong association with an induced radioactivity on the product. Therefore, several obstacles have to be overcome in order to promote food irradiation as a safe and useful application of ionizing radiations. The increasing demand for safe and healthy food is another issue that could help to promote the use of these technologies. In Europe, the preservation of food by irradiation is strongly regulated but is still not very popular, in spite of several food safety issues, such as pathogens contamination or insectsâ infestation that could be easily solved by an environment friendly technology, without the use of chemical fumigants. We will present briefly the recent state-of-art of food irradiation research in Portugal, selecting the main results of three collaborative projects funded by national and international agencies, regarding the effects of gamma radiation on physical and chemical parameters of selected materials: fruits, vegetables and mushrooms, toward the objective to keep the focus on this valuable tool for food processing.To the Projects/Agencies that supported this research: Portuguese Government and E.U. funds: PRODER/FEADER/EU (AROMAP Project); Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), and C2TN (RECI/AAG-TEC/0400/2012 and UID/Multi/04349/2013 projects); International Atomic Energy Agency (IAEA) Coordinated Research Project CRP-D6-RC-1163.2 and IAEA Research contract 19220.info:eu-repo/semantics/publishedVersio
Evaluating Rangeland\u27s Grazing Capacity for Livestock and Wild Herbivores Using the Delta Diet Tool and GIS Technology
Rangelands are dynamic and complex systems requiring appropriate adaptive decision-making to calculate grazing capacity integrating livestock and herbivore wildlife. This work describes the development and application of an integrated framework using the microhistological analysis (DeltaDiet tool) to identify key forage used by different herbivores from the same area associated with GIS technology to mapping landscape containing forage productivity and quality information. This study was conducted in a management unit, representative of the NhecolĂąndia sub-region landscape, Pantanal. During the dry period, representative fecal samples were collected from cows, capybaras and deer grazing in the same management unit for diet analysis, using the DeltaDiet tool. A field survey was conducted to assess key forage composition and utilization degree of the pastures. Landscape units and satellite image maps were made in order to define the main pastures categories. An algorithm was used to evaluate grazing capacity for livestock and wildlife integrating all the diet and pastures information as well as information available from the literature. It was then possible to define grazing capacity for each pasture categories and quality of diet selected by different herbivores
Food irradiation as a key to reduce food waste and guarantee food safety
Food waste is being in the focus of recent global policies, to tackle food scarcity and to overcome ânutritional povertyâ in several countries. Otherwise, a global food market is being the key to make available several products to different populations. These vectors for food policy must be supported by several orientations, to attain their final objective: better and enough food for the world population. For that, different post-harvest processing technologies are making their fundamental contribute. Among that, the preservation of food by irradiation, a physical process that does not use chemicals, is making its way in several countries, to accept imported or exported products without pests (insects), without foodborne pathogens, and also to extend the shelf life of processed products, stopping enzymatic degradation and reducing microorganisms that contribute for food spoilage. We have been studying the effects of gamma and e-beam radiation for food preservation of several Mediterranean products, including chestnuts, mushrooms and aromatic plants, berries and tomatoes, using an experimental gamma chamber with 60Co sources and an electron accelerator with the maximum energy of 10 MeV. And here we present these technologies, their limitations and advantages, the effects on relevant properties of food (e.g. color, texture, nutritional parameters), and question why food preservation by irradiation is underused, since its first use has more than 100 years and its first industrial application has more than 50 years.FCT (Portugal), FEDER PT2020 (UID/AGR/00690/2019), C2TN (UID/Multi/04349/2013), IAEA CRP D61024.info:eu-repo/semantics/publishedVersio
Parent's reports of lexical and grammatical aspects of toddlers's language in European Portuguese: developmental trends, age and gender differences
The results from a large-scale study on toddlersâ language acquisition in European Portuguese are presented. Toddlersâ lexical and grammatical competencies were assessed using the MacArthurâBates Communicative Development Inventory: Words and Sentences. The results, based on 3012 reports completed by parents, indicate an increase in the lexical size and on five measures of grammatical development (production of regular morphology, irregular morphology, over-regularizations, mean length of utterances and sentence complexity) across age groups. A main effect of gender was found for lexical size, production of regular and irregular morphology, production of over-regularizations and sentence complexity, with girls obtaining overall higher scores than boys. All lexical and grammatical development measures are positively correlated, even after controlling for age and gender effects. These findings are discussed in terms of their consistency with those obtained for other languages.CiPsi - Psychology Research Centre, Uminho (UID/PSI/ 01662/2013), PortugalCIEC â Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portugalinfo:eu-repo/semantics/publishedVersio
Infusions from Thymus vulgaris L. treated at different gamma radiation doses: effects on antioxidant activity and phenolic composition
The use of ionizing radiation dates back to many years ago, and is accredited for application in different foods with several purposes. It has been increasingly used in many countries for the treatment of aromatic plants. Thymus vulgaris L. (thyme) is a plant commonly used by food, pharmaceutical and cosmetic industries representing a natural source of several bioactives such as phenolic compounds. The aim of this work was to evaluate the effects of gamma radiation on the antioxidant activity (measured through the free radical scavenging activity, reducing power and lipid peroxidation inhibition) and phenolic compounds profile (obtained by HPLC-DAD-ESI/MS) of infusions prepared from irradiated thyme. The results showed that gamma irradiation at the dose of 10 kGy improved the free radical scavenging activity, reducing power and lipid peroxidation inhibition capacity of the studied infusions, while increasing significantly the concentrations of methyleriodictyol-O-pentosylhexoside, luteolin-7-O-glucoside, eriodictyol and total flavonoids content. Thus, gamma radiation could be considered as a suitable treatment to be used in Thymus vulgaris L., herein validated for its bioactive parameters.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programe PT2020 for financial support to CIMO (UID/AGR/00690/2013), LSRE (Project UID/EQU/50020/2013), C2TN (RECI/AAG-TEC/0400/2012), L. Barros (SFRH/BPD/107855/2015) and R.C. Calhelha (SFRH/BPD/ BPD/68344/2010) grants. The authors are also grateful to Ministry of Agriculture, Portugal (Project AROMAP - PRODER/FEADER/EU), for financial support of the work and E. Pereira grant, and to PragmĂĄtico Aroma Lda company for providing the âMaisErvas - AromĂĄticas e Medicinaisâ samples
A FĂsica aplicada Ă qualidade alimentar: identificação de metais por âpixeâ em castanhas
A concentração na castanha de minerais como o cålcio, potåssio, o magnésio e
outros tem sido estudada tradicionalmente por absorção atómica ou por
espectrofotometria de UV-VIS [1-2]. Neste trabalho foi estudada a composição
elementar de duas variedades (Longal e Judia) de castanha europeia (Castanea
sativa Mill.) com a técnica PIXE (Proton Induced X-ray Emission). Os resultados
preliminares mostram que a composição difere de acordo com a variedade, nos
elementos maioritĂĄrios e nos minoritĂĄrios. Este estudo Ă© parte de um projecto mais
amplo, que visa avaliar o efeito do processamento pĂłs-colheita de alimentos com
feixe de electrĂ”es e raios-X.Coordinated Research Project D61024 ââDevelopment of New Applications
of Machine Generated Food Irradiation Technologiesââ, AgĂȘncia Internacional de Energia
AtĂłmica (AIEA)
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