AGRICULTURAL SCIENCES, 4

Author: FERNÁNDEZ-BARREDO Y DEL AMO M. SALCEDA.
Year: 2006.
University: CARDENAL HERRERA CEU.
Place of defense: CARDENAL HERRERA-CEU.
Place of preparation: CARDENAL HERRERA-CEU.

Summary: This study describes the distribution of Hepatitis E virus (HEV) in a naturally infected swine population and the genetic relatedness of HEV strains on swine farms in Spain. Of fecal and serum samples collected from 191 pigs and manure-ditch samples collected from 21 farms, HEV was detected in 19%, 12%, and 38%, respectively, for an overall prevalence rate of 25%. The maximum prevalence rates for feces and serum were in pigs 13 to 16 wk old. A high prevalence of the virus in feces (18%) was observed in sows. Gene sequencing was performed on 30 strains from feces, serum, and manure ditch: the nucleotide identities varied from 85% to 99% when compared with those of other strains of genotype 3 isolated from swine. This is the first study in Europe to show the variation in virus distribution by age in feces and serum in a naturally infected swine population.

Author: CALDÉS GÓMEZ NATALIA.
Year: 2006.
University: POLITÉCNICA DE MADRID.
Place of defense: E.T.S.I.AGRONOMOS.
Place of preparation: ESCUELA TÉCNICA SUPERIOR DE INGENIEROS AGRÓNOMOS.

Summary: The multiple crises afflicting the developing countries can have devastating effects in the short and long term. In this context, it is of great significance greater and better understanding of the types of crises as well as the determinants of risk management strategies that take household. Also, the search for interventions to the most vulnerable families in crisis contexts is a priority by the international community. This research aims to contribute to this area of knowledge mediente analysis of the impact of a program of transfers Monetary Condicionadas (TMC) in a context of crisis. To this end, this research is nurte approximately panel data of more than a thousand families in Nicaragua collected to assess the impact of the program of the Network of Social Protection for the years 2000 and 2002. Due to the experimental design of the sample, only half of all households that received the program, in which they selected at random. Additionally, and in Nicaragua during the period studied, happened two major crises-the coffee crisis and sequía- that unevenly affect the welfare of these families .. Using the method of double difference and econometric estimates, these data allow evaluate, in a context of crisis, the effectiveness of the program of the Network of Social Protection of Nicaragua as a tool to reduce the vulnerability of households, and especially , to protect food safety and investment in human capital. The results of this research show that, before the event of a crisis, programs TMC Can be an effective tool to boost the present and future development of the poorest rural households. However programs TMC They can not, by themselves, solve the crisis. This involves simultaneously attacking the root of the crisis by adopting other measures to strengthen the productive apparatus of households.

Author: Estévez Amador Jana.
Year: 2006.
University: SEVILLA.
Place of defense: Facultad de Farmacia. Universidad de Sevilla.
Place of preparation: Dpto. Microbiología y Parasitología. Facultad de Farmacia. Universidad de Sevilla..

Summary: The rhizosphere is home to a large and diverse community of microorganisms prokaryotes and eukaryotes that interact and compete among themselves and with the root of the plant. Thus, the activity in a certain member of the community will affect the growth and physiology of the other, and as a result, the physical and chemical properties of soil (Rainey, 1999). Among all these interactions, enjoyed great importance those providing N2 to the ecosystem in which they find themselves, thus ensuring sufficient input from key constituent of essential molecules like proteins and nucleic acids. One example is the association that sets pulses with the group of bacteria known as "rizobios", considered the interaction fixing of N2 most significant within the agricultural area (Burdman et al., 1998). This symbiotic relationship between the rizobios and their hosts is the result of a complex process of exchange of signals between the two (Day et al. 2000). At the plant, favonoides determianarán range symbionts compatible, activating the expression of some specific bacterial genes (genes nod) coding for the synthesis of a second signal, the ripples factors (also known as factors Nod). Growth by C.balustinum Aur9 plants Jewish was effective only during losprimeros days of the trial, with a breakthrough process nodulation, although the parameters of nodulation were equipped in the last days of the study for the simple treatments and doubles. Based on these results, future studies should be conducted to ascertain with certainty mechanisms employees by the PGPR C. Balustinum Aur9 for pormover growth in soybean plants and Jewish, since Lucas-García et al. (2004 a) indicate that the observed variability of the responses largely depend on the stage of the process that this PGPR is capable of change: Infection, nodulaicón or nitrogen fixation. At the same time, there should have encyclical onsideración protocols work proposed by these same authors, to ensure synergy between rixobios and PGPRs and avoid the negative effects arising from the phenomenon of understanding.

Author: CÁNOVAS BERNABÉ SEBASTIÁN.
Year: 2006.
University: MURCIA.
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: The interaction between sperm and eggs is curcial for successful fertilization. In vitro this interaction assumes greater importance. So far the zona pellucida (ZP) is considered the main structure responsible for the blocking of polispermia and union and heterologous sperm penetration (of various species). However, these functions do not meet its goal of a completely efficient in all species under in vitro conditions. The polispermia is a common problem in in vitro fertilization (IVF) in pigs and cattle, while the interaction heterologous espermatozoide-ovocito has been demonstrated. The objectives were to study the blocking of polispermia pigs and cattle to improve the outcome of IVF (interactions counterparts) and investigate possible interactions heterologous (human sperm and oocyte pig) with the goal of oocytes pigs to evaluate the ability of sperm fecundante human. The results show that one can get the hardening of the ZP of cattle and pigs matured oocytes in vitro fertilization before as occurs in vivo, using chemical agents (DTSP), or fluid oviductal (FO) cattle. The effect of FO decreases with time when oocytes were incubated in the midst of fertilization. When using oocytes treated (DTSP or FO) monospermia increases and the number of sperm per oocyte decreases, increasing the performance end, showing that the tightening is involved in blocking the polispermia. In heterologous interactions is found that human sperm may interact with the pig ZP and suffer acrosomal reaction (AR) in a high percentage. However when using oocytes pigs without ZP human sperm can not penetrate the oolema, unlike what happens in the test hamster. By sperm microinjection human sperm can descondensar the nucleus, forming pronúcleos and activate the oocyte, noting that in the samples tested donor fertility can be seen splitting the 20 hours postinyección.

Author: Purriños de la Santa Cruz Clodoaldo.
Year: 2006.
University: LA LAGUNA.
Place of defense: FACULTAD DE FARMACIA.
Place of preparation: Facultad de Farmacia.

Summary: It provides a comprehensive review on the various pests that afflict agriculture in the islands, as well as the different types of pesticides used with particular emphasis on the mechanisms of action and risk both for health and the environment. It also describes alternatives to the use of conventional pesticides. On the other hand, describes the results of a survey that was conducted on the incidence of pests in the two provinces of the Commonwealth Canaria. It offers a comprehensive review of the pesticide plant with the potential both universal and Caniarias, describing 1311 and 374 species, respectively. Finally, we present the results of various investigations into various farms growing ornamental and edible plants both, in order to asesorales on natural methods best suited to attack the pests.

Author: PEREIRA LESTAYO VÍCTOR.
Year: 2006.
University: SANTIAGO DE COMPOSTELA.
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: The need to improve production and prevent various diseases has led nutritionists to incorporate additives livestock, such as monensin, the animal feed bait. However, the entry into force of EU rules, which prohibits the use of this antibiotic from the beginning of the year, has forced her to find credible alternatives can be used as organic malic acid. The latest research was supported in vitro studies, in which it has been observed that malato stimulates growth of Selenomonas ruminantium, a bacterium Gram-negativa representing 51% of the total population of rumen bacterial calves fed diets rich beans. However, although these studies lab have deepened in the mechanisms of action of this acid and its relationship with S.ruminantium also have the particularity to have been made under conditions somewhat remote from the reality livestock, it was necessary analyze what impact might the organic acid when it was applied in vivo. In older people, many questions remained to be resolved in this regard, most relating to what is more property nutritional strategy to achieve maximum performance with this additive. This Doctoral thesis consists of three experimental designs, from which genetic try to learn a little more about how this organic acid and not just talking about parameters productive, but analyzing different aspects of metabolism internal calves (namely on the balance acid, the balance hidroelectrolitico, energy metabolism on L-lactato). With these experiments we intend to not only ensure that the different chemical formulations of malic acid is a valid alternative productive, but is also reliable and safe from the point of view metabolic. To this end we develop different nutritional strategies that will enable us to know under what conditions diet is most effective. The three experimental designs were made in a commercial farm belonging to the company COREN, SCL located in the province of Orense. Regardless of the objective of each specific design, they all felt studying the effectiveness of organic acid throughout the production cycle of calves in fattening (growth and finishing). In a first experiment compared the response of the two promoters, and monensin malato under the same conditions nutritional (rations rich in grain and low percentage of FB) to ascertain whether the malato is a valid alternative for the future. The second experiment was aimed at the possibility of using sodium malato as an alternative in the production of calves to bait monensin, and the need to know under what conditions nutrition is more effective. Specifically, in this experiment we try to learn in detail how malato as an additive in diets rich in grain and with great input from FB. The third experiment main objective was to assess the effects of two chemical forms of malato (malic acid and a salt business malato) on the metabolic parameters and productive. The realization of this Doctoral Thesis has enabled us to conclude that the organic acid malic, in any of its chemical formulations, it is a valid alternative to monensin sodium from the point of view of production. Although, after the analysis of the animal's internal use of the sodium salt form of malato seem to be much safer than the acid on animal health. Anyway, we believe it necessary to conduct further investigations before the concern involves endencia to alcalemia found consistently in all experiments.

Author: RUBIO ASENSIO JOSE SALVADOR.
Year: 2006.
University: MIGUEL HERNÁNDEZ DE ELCHE.
Place of defense: ESCUELA POLITECNICA SUPERIOR DE ORIHUELA. UNIVERSIDAD MIGUEL HERNANDEZ.
Place of preparation: ESCUELA POLITÉCNICA SUPERIOR DE ORIHUELA. UMH.

Summary: The overall objective is to optimize through water management and fertilization, production of crude when used pepper waters of low quality. It aims to establish the optimum levels of K and Ca, and determine the criteria for the management of irrigation cultivation of pepper in coconut fiber. The first experiment was in hydroponics cultivation pepper with 4 levels Ky 4 Ca, conditions and saline control. In the second experiment was growing in coconut fiber to constant volume 4 nutritional solutions, monitoring, control + sn, diluted to 1 / 2 + Ca, sn, diluted to 1 / 2 and sn, mM NaCl. The third experiment was conducted in fiber cococon 4 frequencies risk adjusted to maintain the solution drainage below 130% of the sn. The main conclusions are: hidropónico cultivation using high concentrations of K in the vegetative stage of development, to reduce the fruiting. Doing the opposite with the concentrations of Ca, to reduce the effects of salinity on the rot of pepper. In crop in coconut fiber should reduce the frequency of irrigation water quality and increase when using saline water.

Author: SHIVA RAMAYONI CARLOS.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: UNIDAD DE MICROBIOLOGÍA DE LA FACULTAD DE VETERINARIA.

Summary: The fundamental aim of the doctoral thesis, is to provide an alternative to antibiotics as growth promoters in animals. Here were evaluated products prepared from natural extracts, including excerpts from Rutáceas and organic acids. The specific objectives of this research are summarized as follows: 1. To evaluate the antibacterial and antifungal activity in vitro extracts of natural bacteria and fungi that are important production and animal health, and its activity to be added together with organic acids, determining the methodology to be followed. 2. Evaluation of microbiological parameters and pork production at different stages of their growth cycle, to provide added excerpt feed mixed with natural organic acids, such as growth promoters. Based on the results obtained in vitro tests, it is noted that the method of Aromatograma in combination with the agar diffusion allows an accurate assessment, the antimicrobial activity of natural extracts in combination with organic acids or not. We also indicate that the dilution method microplate sets the minimum inhibitory concentrations of plant extracts on bacteria and fungi, comparing output between products. We suggest that extracts Rutáceas evaluated in our experiments have inhibitory activity for bacteria to fungi, with a greater capacity inhibitory off the Gram positive bacteria on Gram negative bacteria tested. By mixing extracts Rutáceas and organic acids there is a clear synergy that is manifested in a substantial increase in the inhibitory activity of the resulting product compared to bacteria and fungi. When extract Rutáceas adds to substrates such as rice and maize contaminated with Aspergillus ochraceus producer of ochratoxin A, is able to inhibit fungal growth and the production of ochratoxin A, and this excerpt can be used as a control system involved in Food Safety. It has been shown that the extract Rutáceas tested possess enzymatic activity, checking the presence of: esterase, lipase, phosphatases and N-acetil-b- glucosaminidasa. At adicionarlo a crop in liquid medium of Escherichia coli or Salmonella typhimurium, it is able to modify the metabolism of these microorganisms, working in the loss of viability of the strains tested. When extracts Rutáceas are added to substrates for food (compound feed raw materials, among others), the effective concentration to be able to monitor and maintain the microbiological quality varies as a result of the ability of the parent to help spread and the presence of inhibitory substances, among other factors. Defined characteristics of inhibitory extracts tested in vitro, we proceeded to study the in vivo activity of those who submitted the best results can be noted that its addition to the diet of pigs, weaned, as adults, does not diminish the daily intake of I think, on the contrary, increase, and increases the average daily gain, determining a better conversion rate from 21 to 63 days of growth, comparing the results with those found in pigs weaned at which they were provided with antibiotics as promoters of growth during the same time period. It has also been evidenced by the fact that supply in the diet of pigs at weaning and in fattening, a mixture of extracts from Rutáceas is a correct measure, which boosts its parameters productive presents positive effects on intestinal microbiota as decreases counts the enteric microbiota and increases the presence of lactic acid bacteria and does not regulate harmful effects on the animal.

Author: GRAU MARTÍNEZ LAURA.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: This paper investigates the effect of the modulator diets hiperlipídicas corn oil and olive oil on breast carcinogenesis pilot. The results note that the corn oil diet leads to the development of mammary tumors in an otherwise clinical and histopathological greater biological aggressiveness, while the tumors of animals fed the diet of olive features lower malignancy. The effect would be exercised, at least in part, through the regulation of molecular mechanisms. These include adjusting the route of cell proliferation ErbB-Ras-ERK/Akt frequently deregulated in breast cancer, and gene associated with the differentiation of the mammary gland.

Author: ALVARO FUENTES JORGE.
Year: 2006.
University: LLEIDA.
Place of defense: E.T.S. DE INGENIERIA AGRARIA UDL.
Place of preparation: ESTACION EXPERIMENTAL AULA DEI CSIC.

Summary: The main objective of this study was to assess the effects of tillage and cropping system in stabilizing and sequestration in soil organic C, and to identify the factors that control these processes, as well as the role of soil aggregation the fijaciÓn C, in the semi-arid ecosystems of dry valley of the Ebro. To accomplish this goal were selected three trials of long-term tillage in Selvanera and Agramunt (province of Lleida) Peñaflor yen (Zaragoza province). In the trial of Selvanera (land Xerocrept fiuventic; average annual rainfall. 475 mm) comparing four tillage systems (conventional tillage, with tilling soil tillage, reduced tillage and no-Iaboreo). In Agramunt (suelo. Xerofluvent typic; average annual rainfall: 430 mm) were compared four tillage systems (conventional tillage, with tilling soil tillage, reduced tillage and no-laboreo) under a rotation cebada-trigo. Finally, Peñaflor (land: Xerollic Calciorthid; average annual rainfall: 390 mm) were compared three tillage systems (conventional tillage, reduced tillage and no-laboreo) and two cropping systems (one rotation cebada-barbecho and a monoculture barley). In order to calculate the balance of soil organic C, C losses in the soil were determined for three campaigns crop (2002-2003, 2003-2004 and 2004-2005) in testing and Peñaflor for two campaigns ( 2003-2004 and 2004-2005) in Agramunt and Selvanera. CO2 emissions from soil to the atmosphere were measured every 15 days, throughout the campaign crop, and lower ranges (hours) at times ad hoc work. Gains of organic C were estimated from the root biomass and production of straw in the harvest of the three campaigns. Also, in testing Peñaflor and along two campaigns, tracked the aggregate of the superfICie soil, according treatment tillage and cropping system. To that end, characterized the aggregate size distribution and stability of the aggregates water. Also, three samplings were conducted in post-harvest, in order to study the influence of different fractions of organic matter (particulate organic matter and organic matter associated mineral) in the state of aggregation of soil (campaigns 2002-2003 and 2003-2004 ) and its distribution in the soil profile (campaign 2004-2005). In the first 5 cm of soil, system no-laboreo accumulated between 50% and 100% more organic C that the conventional system with vertedera and between 20% and 50% more C in the form of organic matter particulate and C mineral-asociado. However, this behavior was reversed in deeper horizons where the system no-Iaboreo happened to have the lowest values and conventional tilling the highest. The intensification of cropping systems led to a higher content of soil organic C in all tillage systems. The study fractions of soil organic matter depending on the state of aggregation has shown that no-laboreo, compared to tillage systems, favors the stability of macroaggregates soil, and therefore, in the long run, abduction of organic C in these macroaggregates. Under no-Iaboreo, organic C stabilized in macroaggregates is in the form of organic matter intra-particulada occluded within the microaggregates formed in the interior of macroaggregates. The state of aggregation of soil presents a dynamic time-dependent state of development of the crop, having seen a drop in the stability of the aggregates after the death of the crop. During the campaign cultivation, CO2 emissions from soil wing atmosphere is a 30% and 5% higher in tillage and conventional tillage reduced, respectively, in no-laboreo. Older 8 diferenc 4d7 ias in CO2 emissions are observed between no-Iaboreo and the rest of tillage treatments for the implementation of the work. In most cases, the stock of C shows losses of organic C in all systems and tillage farming. However, under no-Iaboreo these losses are between 20 and 50% lower than under conventional tillage. Also, the rotation cebada-barbecho showed further loss of C organic monoculture of barley due to lower contributions from the soil organic C from crop residues.