169 research outputs found
Manual de pràctiques de protecció de cultius
Grau en Enginyeria Agroalimentària i del Medi rural. Codi assignatura: AG101
Optimization and sensitivity analyses of a combined cooling, heat and power system for a residential building
In the quest for a better use of energy resources, energy integration and cogeneration strategies have been employed in the industrial and commercial sectors with considerable benefits realized. However, the residential sector remains underexplored. An optimization procedure should be carried out whenever there is a need to ensure or verify the economic viability of an energy system. This study uses Mixed Integer Linear Programming to optimize the energy supply to a residential building, with 20 floors and 40 apartments, located in the city of João Pessoa (Northeast Brazil). The equipment available includes gas engines, electric and natural gas boilers, heat exchangers, cooling towers, and absorption and mechanical chillers. The optimization establishes the optimal system configuration and operational strategy (operation throughout the year). Economic, technical, and legal aspects were considered in the minimization of the total annual costs associated with the building's energy supply. The energy demands were calculated on an hourly basis, throughout one year, by the EnergyPlus software and corresponded to hot water (83 MWh/year), electricity (171 MWh/year) and cooling (242 MWh/year) demands. The optimal system was entirely reliant on the electric grid to meet the electricity demand directly and to satisfy heating and cooling demands by means of an electric hot water boiler and a mechanical chiller. The optimal solution is tested by varying, within reasonable limits, selected parameters: natural gas and electricity tariffs, the behavior of residents, amortization factor and relationship between the tariffs of electricity and natural gas
When do predatory mites (Phytoseiidae) attack? Understanding their diel and seasonal predation patterns
Predatory mites of the Phytoseiidae family are considered one of the most important groups of natural enemies used in biological control. The behavioral patterns of arthropods can differ greatly daily and seasonally; however, there is a lack of literature related to Phytoseiidae diel and seasonal predation patterns. The predatory activity of three phytoseiid species (two Tetranychidae‐specialists, Phytoseiulus persimilis and Neoseiulus californicus, and one omnivore, Euseius stipulatus) that occur naturally in Spanish citrus orchards was observed under laboratory conditions in winter and summer. The temperature and photoperiod of the climatic chamber where the mites were reared did not change during the experiment. Our study demonstrates that phytoseiids can exhibit diel and seasonal predatory patterns when feeding on Tetranychus urticae (Acari: Tetranychidae). Neoseiulus californicus was revealed to be a nocturnal predator in summer but diurnal in winter. In contrast, P. persimilis activity was maximal during the daytime, and E. stipulatus showed no clear daily predation patterns. The predatory patterns described in this study should be taken into account when designing laboratory studies and also in field samplings, especially when applying molecular techniques to unveil trophic relationships
Molecular characterization of Cardinium, Rickettsia, Spiroplasma and Wolbachia in mite species from citrus orchards
Tetranychidae spider mites are considered key citrus pests in some production areas, especially Tetranychus urticae Koch. Over the past decades, pesticide overuse seems to have
promoted T. urticae population selection in citrus orchards. However, the microbiota has
also been pointed out as a plausible explanation for population structure or plant host specialisation observed in several arthropod species. In this work, we have determined the
incidence of Cardinium, Rickettsia, Spiroplasma and Wolbachia as representatives of
major distorter bacteria genera in Aplonobia histricina (Berlese), Eutetranychus banksi
(McGregor), Eutetranychus orientalis (Klein), Panonychus citri (McGregor), Tetranychus
evansi Baker and Pritchard, Tetranychus turkestani Ugarov and Nikolskii, and T. urticae
populations from Spanish citrus orchards. Only Wolbachia was detected by PCR. The
multilocus alignment approach and phylogenetic inference indicated that all detected Wolbachia belong to supergroup B. The deep analysis of each 16S rDNA, ftsZ and wsp gene
sequences allowed identifying several phylogenetically diferent Wolbachia sequences. It
probably indicates the presence of several diferent races or strains, all of them belonging to supergroup B. The wsp sequence typing analysis unveiled the presence of the two
already identifed alleles (61 and 370) and allowed to contribute with fve new alleles, supporting the presence of diferent but related B-races in the studied mite populations. The
results are discussed and related to T. urticae population structure, previously observed in
Spanish citrus orchards
Successful Treatment of Chronic Mucocutaneous Candidiasis Caused by Azole-Resistant Candida albicans with Posaconazole
Refractory or recurrent infections of skin, nails, and the mucous membranes are clinical signs of chronic mucocutaneous candidiasis, frequently associated with immunological defects. Here we describe a 39-years-old female patient, with familial CMC, that presented with an extensive infection caused by an azole-resistant Candida albicans isolate, successfully treated with posaconazole
Nutritional characteristics of forage grown in south of Benin
In order to provide recommendations on the most useful forage species to smallholder farmers, eleven grass and eleven legume forages grown in Abomey-Calavi in Republic of Benin were investigated for nutritive value (i.e. chemical composition and energy content) and fermentation characteristics (i.e. gas and volatile fatty acid production, organic matter degradability). The in vitro gas production technique was used, incubating the forages for 120 h under anaerobic condition with buffalo rumen fluid. Compared to legume, tropical grass forages showed lower energy (8.07 vs 10.57 MJ/kg dry matter [DM]) and crude protein level (16.10% vs 19.91% DM) and higher cell wall content (neutral detergent fiber: 63.8% vs 40.45% DM), respectively. In grass forages, the chemical composition showed a quite high crude protein content; the in vitro degradability was slightly lower than the range of tropical pasture. The woody legumes were richer in protein and energy and lower in structural carbohydrates than herbaceous plants, however, their in vitro results are influenced by the presence of complex compounds (i.e. tannins). Significant correlations were found between chemical composition and in vitro fermentation characteristics. The in vitro gas production method appears to be a suitable technique for the evaluation of the nutritive value of forages in developing countries
Acetyl-L-carnitine supplementation differently influences nutrient partitioning, serum leptin concentration and skeletal muscle mitochondrial respiration in young and old rats.
Variations in energy balance, body composition, and nutrient partitioning induced by acetyl-L-carnitine (ALCAR) supplementation were studied in young (2 mo) and old (24 mo) Wistar rats. Changes in skeletal muscle metabolism as well as in serum free triiodothyronine and leptin levels were also evaluated. Rats were administered 0 (control) or 15 g/L ALCAR in their drinking water for 1 mo. ALCAR treatment significantly decreased body lipid percentage in young rats and significantly increased body protein percentage in old rats. The percentage of metabolizable energy (ME) intake stored as lipid was lower in ALCAR-treated young rats, whereas the percentage of ME intake stored as protein was greater in ALCAR-treated old rats compared with their age-matched controls. In addition, ALCAR supplementation significantly decreased serum leptin levels in old rats. Elevated skeletal muscle respiration was found in old rats treated with ALCAR, due to an increase in mitochondrial protein mass. In conclusion, ALCAR supplementation decreases efficiency of lipid deposition in young rats and increases efficiency of protein deposition in old rats. In addition, ALCAR supplementation partly reduces the leptin resistance that occurs in old rats, and improves ATP production in skeletal muscle mitochondria through an increase in mitochondrial protein content
Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus
The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains
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