973 resultados para Protection by p-cycles
Resumo:
Se ha aplicado el Control Integrado de Plagas en unas 40 parcelas comerciales de manzano de Girona y de Lleida desde 1991 a 1993 con el objetivo de controlar biológicamente la araña roja (P. ulmi) mediante ácaros Phytoseiidae. Así mismo, se ha evaluado la estrategia de control de esta plaga, se han evaluado los factores principales que pueden influir en el éxito del control biológico y se ha diseñado una estrategia de defensa sencilla. En la mayoría de los casos, el control biológico se ha debido a la acción de Amblyseius andersoni o a la acción combinada de A. andersoni y A. californicus. A. andersoni impide el desarrollo de poblaciones elevadas de araña roja y la aparición de daños por decoloración. En las parcelas de Girona se ha producido la sustitución paulatina de A. californicus por A. andersoni. Los factores determinantes del éxito del control biológico fueron el nivel de actividad de P. ulmi y la presencia de A. andersoni, lo que plantea nuevas cuestiones relativas a cómo se puede favorecer la implantación de esta especie en parcelas comerciales. Finalmente, se propone una estrategia de defensa sencilla, basada en la época de aparición de la plaga y de los fitoseidos y en la relación que se establece entre ambas poblaciones durante el ciclo vegetativo.
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«Crise de l'assurance-vieillesse », «déséquilibre démographique», «vieillissement de la population », « faillite des systèmes de retraite », voilà des expressions qui occupent une place prépondérante dans tes discours portant sur l'avenir de la sécurité sociale aujourd'hui. Les autorités politiques suisses comme européennes font part de leur inquiétude face à la situation d'urgence que présenteraient les « sociétés vieillissantes ». En effet, alors que F assurance-vieillesse s'adressait initialement à une catégorie résiduelle de personnes qui parvenait à vivre plusieurs années au-delà de 65 ans, elle couvre maintenant près d'un cinquième de la population globale. Partant, les autorités fédérales appellent à une restriction des conditions d'accès à la rente de vieillesse. À première vue, les débats qui portent sur cette question dans l'arène politique relèvent de considérations essentiellement techniques liées aux conditions économiques de perpétuation de l'assurances-vieillesse. Il s'agit de modifier les règles d'accès à l'assurance ainsi que le montant des prestations afin d'assainir les caisses tout en faisant face à l'augmentation du nombre de retraités. Ce travail de thèse aborde cette question par une autre approche. Nous partons du postulat que les débats portant sur l'avenir de la politique de la vieillesse sont révélateurs d'une lutte entre acteurs du champ de régulation sociale qui participent d'un travail d'élaboration d'une pensée d'Etat, au sens de P Bourdieu. Cette lutte a pour objet l'imposition de catégories de pensées, soit la définition de ce qu'est un âgé aujourd'hui et de ce qu'il est moralement acceptable d'attendre de lui Nous montrons que cette question peut être comprise à l'aune de l'histoire du traitement social de la vieillesse dont nous relatons ici la genèse et les transformations. Nous soulignons également combien cette pensée d'Etat marque la manière dont les retraités aujourd'hui cherchent à se valoriser face à la déstabilisation de leur statut social. Summary "Crisis of social insurance for older people", "demographic imbalance", "aging of the population", "bankruptcy of pensions systems" ; these are some of the many expressions that today play a importance part in discussion about the future of social security. The Swiss and European political authorities show they are concerned about the crisis that "aging societies" are said to be facing. Indeed, while social insurance for old age used to concern a residual category of people who managet! to live to more than 65 years old, it now covers about a fifth of the global population. Hence, the Federal authorities are calling for a tightening of the conditions for access to retirement benefits. At first glance, the debates in the political arena »elated to (his question mainly deal with technical considerations linked to the economic conditions for the perpetuation of the insurance for old age. Ease of access and the level of the benefits have to be reduced in order to balance the funds, in the face of the rise of the number beneficiaries. This thesis study addresses this question through a different approach. We start from the proposition that debates concerning the future of social policy for old age reveal a struggle between those involved in (he field of social regulation ; this struggle is part of the development of the thought of the State as conceived by P. Bourdieu. The aim of this fight is to impose normative categories of thought, that is to say in relation to our subject, the definition of what an older person is today and what is morally acceptable to expect of him or her. We show that this question can be understood in the light of the the history of the social treatment of old age that we report here. Moreover, we show that this thought of the State explains the way retired people seek to value themselves and confront the destabilisation of their social status.
Resumo:
Työssä selvitettiin vastusvenymäliuskamittausten avulla sekoitinakselin kuormitukset sekä perehdyttiin väsymisilmiöön ja hitsattujen rakenteiden väsymismitoitukseen. Kuormitusten mittauksessa rekisteröitiin akselin kriittisen kohdan taivutus- ja vääntövenymät. Mittaustulosten avulla tutkittiin kuormituksia ja kuormitusten luonnetta sekä johdettiin väsymismitoitusperusteet sekoitinakseleille. Väsymismitoitus perustuu kahteen eri menetelmään. Vakioamplitudiseen väsymisrajaan perustuvassa menetelmässä vaihtuva-amplitudisella jännityksellä suurinkin jännitysheilahdus jää väsymisrajan alle. Kokonaisväsymisvaurioon perustuvassa mitoituksessa puolestaan sallitaan vakioamplitudisen väsymisrajan ylitys. Kestoikä on käytetty loppuun, kun väsymisvaurio saavuttaa väsymiskestävyyden arvon. Menetelmän valinta riippuu käytettävästä sekoitinelintyypistä ja käytön aikana ilmenevistä väsymisen kannalta vaarallisista tilanteista.
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The Bohnenblust-Hille inequality says that the $\ell^{\frac{2m}{m+1}}$ -norm of the coefficients of an $m$-homogeneous polynomial $P$ on $\Bbb{C}^n$ is bounded by $\| P \|_\infty$ times a constant independent of $n$, where $\|\cdot \|_\infty$ denotes the supremum norm on the polydisc $\mathbb{D}^n$. The main result of this paper is that this inequality is hypercontractive, i.e., the constant can be taken to be $C^m$ for some $C>1$. Combining this improved version of the Bohnenblust-Hille inequality with other results, we obtain the following: The Bohr radius for the polydisc $\mathbb{D}^n$ behaves asymptotically as $\sqrt{(\log n)/n}$ modulo a factor bounded away from 0 and infinity, and the Sidon constant for the set of frequencies $\bigl\{ \log n: n \text{a positive integer} \le N\bigr\}$ is $\sqrt{N}\exp\{(-1/\sqrt{2}+o(1))\sqrt{\log N\log\log N}\}$.
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Peer-reviewed
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We present a quantitative physiognomic characterization of major macroalgal-dominated assemblages on coastal detritic bottoms of the continental shelf off Mallorca and Menorca (Balearic Islands, Western Mediterranean). In late spring of 2007 and 2008, 29 samples were collected by bottom trawling at depths between -52 and -93 m. These samples were then sorted and identified to their lowest taxonomic level. Statistical analyses distinguished six different assemblage types: shallower water environments (-52 to -65 m in depth) were characterized by Osmundaria volubilis and Phyllophora crispa meadows and two types of Peyssonnelia beds; two assemblage types, Laminaria rodriguezii beds and maërl beds, were only present in deep-water environments (-77 to -81 m); and an assemblage dominated by P. crispa and Halopteris filicina was found in both shallow and deep waters (-57 to -93 m). We assess the distribution of these six assemblage types through the studied area.
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Glycerol, a co-product of biodiesel production, was used as a carbon source for the kinetics studies and production of biosurfactants by P. aeruginosa MSIC02. The highest fermentative parameters (Y PX = 3.04 g g-1; Y PS = 0.189 g g-1, P B = 31.94 mg L-1 h-1 and P X = 10.5 mg L-1 h-1) were obtained at concentrations of 0.4% (w/v) NaNO3 and 2% (w/v) glycerol. The rhamnolipid exhibited 80% of emulsification on kerosene, surface tension of 32.5 mN m-1, CMC = 28.2 mg L-1, C20 (concentration of surfactant in the bulk phase that produces a reduction of 20 dyn/cm in the surface tension of the solvent) = 0.99 mg L-1, Γm (surface concentration excess) = 2.4 x 10-26 mol Å-2 and S (surface area) = 70.4 Ų molecule-1 with solutions containing 10% NaCl. A mathematical model based on logistic equation was considered to representing the process. Model parameters were estimated by non-linear regression method. This approach was able to give a good description of the process.
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Due to their recalcitrant nature, organochlorides are already found in environment and the search for alternatives to eliminate these compounds such as biodegradation using native microorganisms is of great interest. A screening trial to select environmental bacteria able to degrade DDD, PCP and dieldrin was conducted. Among 14 isolates, the soil bacteria Pseudomonas aeruginosa L2-1 showed the highest tolerance to increasing concentrations of the organochlorides and was selected for further studies. Biodegradation was assessed in liquid medium, varying the concentrations of glucose and the presence of rhamnolipids (RL). The best medium for the occurrence of biodegradation of the compounds contained 0.5% glucose, giving approximately 50% yield after three days of incubation. Results showed that the biodegradation rates of the organochlorides by P. aeruginosa L2-1 were greater at low concentrations of glucose and in the presence of rhamnolipids.
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In a survey carried out in the state of Mato Grosso, Brazil, the lesion nematode, Pratylenchus brachyurus, and the root-knot nematode, Meloidogyne incognita, were found, respectively, in 94% and 3.7% of a total of 623 root and soil samples representing 21,793 ha. No visible aboveground symptoms in cotton (Gossypium hirsutum) plants infected by P. brachyurus were observed, except for typical root lesions. In contrast, plants with M. incognita usually exhibited pronounced symptoms of damage. The high frequency (94%) of P. brachyurus was unexpected and is of concern considering the fact that soybean (Glycine max) and corn (Zea mays), are both susceptible to this nematode and are used in crop rotation programs.
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The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning) of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances), the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature) and human interferences (cropping practices and control measures) are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of knowledge and understanding of the etiology and epidemiology of root rot, and its effects on the physiology of the whole plant, are discussed in relation to new research directions and development of better practices to manage the disease in hydroponic crops. Focus is on methods and technologies for tracking Pythium and root rot, and on developing, integrating, and optimizing treatments to suppress the pathogen in the root zone and progress of root rot.
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In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.
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This PhD thesis in Mathematics belongs to the field of Geometric Function Theory. The thesis consists of four original papers. The topic studied deals with quasiconformal mappings and their distortion theory in Euclidean n-dimensional spaces. This theory has its roots in the pioneering papers of F. W. Gehring and J. Väisälä published in the early 1960’s and it has been studied by many mathematicians thereafter. In the first paper we refine the known bounds for the so-called Mori constant and also estimate the distortion in the hyperbolic metric. The second paper deals with radial functions which are simple examples of quasiconformal mappings. These radial functions lead us to the study of the so-called p-angular distance which has been studied recently e.g. by L. Maligranda and S. Dragomir. In the third paper we study a class of functions of a real variable studied by P. Lindqvist in an influential paper. This leads one to study parametrized analogues of classical trigonometric and hyperbolic functions which for the parameter value p = 2 coincide with the classical functions. Gaussian hypergeometric functions have an important role in the study of these special functions. Several new inequalities and identities involving p-analogues of these functions are also given. In the fourth paper we study the generalized complete elliptic integrals, modular functions and some related functions. We find the upper and lower bounds of these functions, and those bounds are given in a simple form. This theory has a long history which goes back two centuries and includes names such as A. M. Legendre, C. Jacobi, C. F. Gauss. Modular functions also occur in the study of quasiconformal mappings. Conformal invariants, such as the modulus of a curve family, are often applied in quasiconformal mapping theory. The invariants can be sometimes expressed in terms of special conformal mappings. This fact explains why special functions often occur in this theory.
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OBJECTIVE:to identify predictors of death in blunt trauma patients sustaining pelvic fractures and, posteriorly, compare them to a previously reported series from the same center.METHOD: Retrospective analysis of trauma registry data, including blunt trauma patients older than 14 y.o. sustaining pelvic fractures admitted from 2008 to 2010. Patients were assigned into group 1 (dead) or 2 (survivors). We used Student's t, qui square and Fisher's tests for statistical analysis, considering p<0.05 as significant. Posteriorly, we compared predictors of death between both periods.RESULTS: Seventy-nine cases were included. Mean RTS, ISS and TRISS were, respectively, 6.44 + 2.22, 28.0 + 15.2 e 0.74 + 0.33. Nineteen patients died (24,0%). Main cause of death was hemorrhage (42,1%). Group 1 was characterized by (p<0.05) lower systolic blood pressure and Glasgow coma scale means on admission, higher heart rate, head AIS, extremity AIS and ISS means, as well as, higher frequency of severe head injuries and complex pelvic fractures. Comparing both periods, we notice that the anatomic and physiologic severity of injury increased (RTS and ISS means). Furthermore, there was a decrease in the impact of associated thoracic and abdominal injuries on the prognosis and an association of lethality with the presence of complex pelvic fractures.CONCLUSION: There were significant changes in the predictors of death between these two periods. The impact of thoracic and abdominal associated injures decreased while the importance of severe retroperitoneal hemorrhage increased. There was also an increase in trauma severity, which accounted for high lethality.
Efficacy of the d-phenothrin/pyriproxyfen association against mites in naturally co-infested rabbits
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The aim of the present study was to evaluate the efficacy of the d-phenothrin/pyriproxyfen association against Psoroptes ovis, Cheyletiella parasitivorax, and Leporacarus gibbus infestations in naturally co-infested rabbits. Twenty crossbreed (New Zealand White x California) rabbits concurrently infested by the three mite species were randomly divided in two groups. All rabbits presented with hyperemia, erythema and formation of crusts in the ear canals caused by P. ovis. Infestations by both C. parasitivorax and L. gibbus were considered asymptomatic in all animals.Ten animals were treated with a 4.4% d-phenothrin and 0.148% pyriproxyfen spray formulation until have their body surface uniformly sprayed, including external ear canals. The other ten rabbits remained untreated, serving as control group. Observations were done on days +7, +14, +21, +28, and +35 post-treatment. The d-phenothrin/pyriproxyfen association showed 100% efficacy against the three mite species and was responsible for the remission of psoroptic mange lesions on treated animals. No signs of intoxication were observed. The results indicate that d-phenothrin/pyriproxyfen spray formulation in a single application is an effective and clinically safe option for the control of different mite infestations in rabbits.
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Tutkielman tarkoituksena on perehtyä siihen, kuinka laajasti tavaramerkin haltija voi kieltää toista elinkeinoharjoittajaa käyttämästä samaa tai samankaltaista merkkiä, kun sitä käytetään samoissa, samankaltaisissa tai jopa täysin erilaisissa tavaroissa tai palveluissa. Merkin haltijan kielto-oikeuden laajuuteen paneudutaan tutkimalla ensiksi EU:n tavaramerkkidirektiiviä ja Suomen tavaramerkkilakia ja oikeuskäytäntöjä. Tämän jälkeen tutkitaan, kuinka laaja kielto-oikeus merkin haltijalla on Kiinassa. Pääasiallinen tutkimusmetodi on lainopillinen, mutta myös oikeusvertailua tehdään Suomen ja Kiinan välillä. Tavaramerkin suojaamisessa on Suomessa selkeästi havaittavissa Chicagon koulukunnan teorian hyväksyminen, joka tavaramerkkioikeuteen sovellettuna korostaa merkin haltijan laajaa suojaa. Teorian mukaan tavaramerkin brandiksi luomiseen liittyviä investointeja pitää suojata ja estää sen ansioton hyödyntäminen. Päinvastaista teoriaa edustaa Harvardin koulukunta, jonka teorian piirteitä on havaittavissa Kiinan tavaramerkkioikeudessa. Se korostaa tavaramerkin kapeaa suojaa. Sallimalla kilpailijoiden jäljitellä tunnettua tavaramerkkiä parannetaan kilpailijan asemaa markkinoilla. Toisaalta ulkomaiset merkin haltijat kohtaavat Kiinassa myös paljon ei-tavaramerkkioikeudellisia ongelmia, jotka vaikeuttavat tavaramerkin suojaamista Kiinan markkinoilla.