944 resultados para Laying
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Objectives: Assess the main problems referred by the patients and observed by the professionals after the bucodental rehabilitation with an implant-supported hybrid prothesis. Patients and Methods: A retrospective study was carried out in which there were 43 patients included who were visited in the Department of Oral Surgery and Orofacial Implantology of University of Barcelona Dental School for one year. An oral rehabilitation with an implant-supported hybrid prosthesis was made to those patients. The following variables were registered: age, gender, number of inserted implants, type of implant and principal problems produced by the hybrid prosthesis. Results: The rehabilitation with an implant supported hybrid prosthesis was only performed in 43 of 116 cases treated in one year (January, 2006 to January, 2007). They were 26 men and 17 women of ages between 37 and 74 years, being the rate age of 56,5 years. The main complication recorded was the mucositis, associated frequently with a difficulty to carry a correct oral hygiene and to an overextention of the tail of resin of the prosthesis. Other observed problems were the peri-implantitis, the break of the acrylic teeth and the loss of some of the prosthetic screws. Conclusions: The most frequent complication after the laying of an implant supported hybrid prosthesis was the mucositis, associated mainly with a prosthetic tail too long and to the consequent difficulty of carrying a correct oral hygiene. In spite of the high prevalence of observed complications, most of them were mild and resolved on subsequent visits.
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Wood ant species show differences in their social structure, especially in the level of polygyny (number of laying queens per nest) and polydomy (number of nest per colony), both within and between species. We demonstrate here for the first time that Formica lugubris displays two different social forms in close proximity in alpine unmanaged forests of the Swiss National Park. The genetic data (7 microsatellite loci) and field data indicate that one population is mostly monogynous to weakly polygynous (r = 0.438) and monodomous, the second one being polygynous (r = 0.113) and polydomous. Within this latter population new nests are founded by budding, leading to the observed high density of nests. These two different social structures, possibly being two expressions of a same continuum, could be explained by several ecological or environmental factors (e.g. habitat saturation, resource competition) and also historical effects.
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This essay examines the American Civil War of 1861 – 1865, which is also known as the bloodiest war that the United States has ever experienced. The pretext for the war was the abolition of slavery in the South, and after many battles the Southern states lost: as a consequence, they experienced major changes in their economic and social life. This interesting piece from American history can be traced out throughout the characters’ lives in the novel Gone with the Wind which has been thoroughly analyzed in order to draw nearer and to comprehend the changes in the Southern way of life before and after the war. The author, Margaret Mitchell, was born in Atlanta, Georgia, and grew up with the stories about the war. As a result, Gone with the Wind studies not only its causes, but also the years after its end – a period which is not generally a subject of history and receives little attention – and the effects that such reversals have on former planters and slaves. From the position of contemporaneity, the reader can see that such changes in a society do not end with the laying down of an act, or in this case the end of the war, but they continue during many years; thus, the modern world can draw conclusions and lessons for events that are happening at the moment.
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Comparative analyses of spatial genetic structure of populations of plants and the insects they interact with provide an indication of how gene flow, natural selection and genetic drift may jointly influence the distribution of genetic variation and potential for local co-adaptation for interacting species. Here, we analysed the spatial scale of genetic structure within and among nine populations of an interacting species pair, the white campion Silene latifolia and the moth Hadena bicruris, along a latitudinal gradient across Northern/Central Europe. This dioecious, short-lived perennial plant inhabits patchy, often disturbed environments. The moth H. bicruris acts both as its pollinator and specialist seed predator that reproduces by laying eggs in S. latifolia flowers. We used nine microsatellite markers for S. latifolia and eight newly developed markers for H. bicruris. We found high levels of inbreeding in most populations of both plant and pollinator/seed predator. Among populations, significant genetic structure was observed for S. latifolia but not for its pollinator/seed predator, suggesting that despite migration among populations of H. bicruris, pollen is not, or only rarely, carried over between populations, thus maintaining genetic structure among plant populations. There was a weak positive correlation between genetic distances of S. latifolia and H. bicruris. These results indicate that while significant structure of S. latifolia populations creates the potential for differentiation at traits relevant for the interaction with the pollinator/seed predator, substantial gene flow in H. bicruris may counteract this process in at least some populations.
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Embryonic development in nonmammalian vertebrates depends entirely on nutritional reserves that are predominantly derived from vitellogenin proteins and stored in egg yolk. Mammals have evolved new resources, such as lactation and placentation, to nourish their developing and early offspring. However, the evolutionary timing and molecular events associated with this major phenotypic transition are not known. By means of sensitive comparative genomics analyses and evolutionary simulations, we here show that the three ancestral vitellogenin-encoding genes were progressively lost during mammalian evolution (until around 30-70 million years ago, Mya) in all but the egg-laying monotremes, which have retained a functional vitellogenin gene. Our analyses also provide evidence that the major milk resource genes, caseins, which have similar functional properties as vitellogenins, appeared in the common mammalian ancestor approximately 200-310 Mya. Together, our data are compatible with the hypothesis that the emergence of lactation in the common mammalian ancestor and the development of placentation in eutherian and marsupial mammals allowed for the gradual loss of yolk-dependent nourishment during mammalian evolution
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Plants activate direct and indirect defenses in response to insect egg deposition. In Arabidopsis thaliana, oviposition by the butterfly Pieris brassicae triggers cellular and molecular changes that are similar to the changes caused by biotrophic pathogens. Even though this innate immune response did not affect egg survival in Arabidopsis, we could show that different insect eggs elicit specific gene expression changes. Additionally, egg- induced necrosis could be observed in a variety of plants from different families ranging from dicotyledonous plants to monocots, suggesting that insect-egg detection by plants is a widespread mechanism and that different insect species contain elicitors of immune responses. Extracts from caterpillars and eggs contain elicitors that co-purified over several extraction steps. Chemical fractionation of caterpillar extracts lead to the characterisation of an active compound that was determined to be a triglyceride by NMR analysis. The exact structure of the side chains as well as the elicitor's presence in insect eggs have yet to be confirmed.We also found that the plant defense signal salicylic acid (SA) accumulates at the site of oviposition. This is unexpected, as the SA pathway controls the defense against fungal and bacterial pathogens whereas it negatively interacts with the jasmonic acid (JA) pathway, which is crucial for the defense against herbivores. Application of P. brassicae or Spodoptera littoralis egg extract onto leaves reduced the induction of insect-responsive genes after challenge with caterpillars, suggesting that egg-derived elicitors suppress plant defense. Consequently, larval growth of the generalist herbivore S. littoralis, but not of the specialist P. brassicae, was significantly higher on plants treated with egg extract than on control plants. In contrast, suppression of gene induction and enhanced S. littoralis performance were not found in the SA-deficient mutant sid2-l, indicating that SA mediates this phenomenon. These data reveal an intriguing facet of the crosstalk between SA- and JA-signalling pathways and suggest that insects have evolved a way to suppress the induction of defense genes by laying eggs that release elicitors. Additionally, we demonstrated that mutants of known crosstalk regulators, including nprl-1, tga2356, ein2-l and wrky70-l, are not affected in egg-induced suppression of herbivore defenses. JA treatment was not able to alleviate this SA/JA negative crosstalk, suggesting that this suppression operates through a novel mechanism downstream of JA biosynthesis.
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Multiple sclerosis (MS), a variable and diffuse disease affecting white and gray matter, is known to cause functional connectivity anomalies in patients. However, related studies published to-date are post hoc; our hypothesis was that such alterations could discriminate between patients and healthy controls in a predictive setting, laying the groundwork for imaging-based prognosis. Using functional magnetic resonance imaging resting state data of 22 minimally disabled MS patients and 14 controls, we developed a predictive model of connectivity alterations in MS: a whole-brain connectivity matrix was built for each subject from the slow oscillations (<0.11Hz) of region-averaged time series, and a pattern recognition technique was used to learn a discriminant function indicating which particular functional connections are most affected by disease. Classification performance using strict cross-validation yielded a sensitivity of 82% (above chance at p<0.005) and specificity of 86% (p<0.01) to distinguish between MS patients and controls. The most discriminative connectivity changes were found in subcortical and temporal regions, and contralateral connections were more discriminative than ipsilateral connections. The pattern of decreased discriminative connections can be summarized post hoc in an index that correlates positively (ρ=0.61) with white matter lesion load, possibly indicating functional reorganisation to cope with increasing lesion load. These results are consistent with a subtle but widespread impact of lesions in white matter and in gray matter structures serving as high-level integrative hubs. These findings suggest that predictive models of resting state fMRI can reveal specific anomalies due to MS with high sensitivity and specificity, potentially leading to new non-invasive markers.
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La fenología y la dinámica poblacional del pulgón del tilo Eucallipterus tiliae Linnaeus han sido estudiadas en parques y jardines de la ciudad de Lleida durante el periodo 2002-2003 en árboles no tratados y en árboles sometidos a tratamiento químico convencional. Los primeros individuos aparecen a comienzos de primavera (abril) y las densidades de población crecen exponencialmente hasta alcanzarse un máximo a finales de mayo. Inmediatamente después del máximo poblacional se produce un descenso brusco de la población hasta la práctica desaparición de los pulgones del árbol. En otoño se detectan machos y hembras ovíparas que hacen la puesta. Esta especie pasa el invierno en forma de huevo. Durante el periodo de mayor abundancia, los pulgones produjeron gran cantidad de melaza causando daños estéticos a los árboles y molestias a los ciudadanos. Estos efectos negativos del pulgón se produjeron a pesar de la estrategia de control utilizada: la aplicación sistemática de insecticidas. El análisis de esta estrategia mostró un número excesivo de tratamientos y una falta de sincronización con la dinámica del pulgón, lo que pone de manifiesto que la estrategia de control de E. tiliae en Lleida puede ser mejorada. Se registró la presencia de diversos enemigos naturales asociados a E. tiliae, principalmente coccinélidos y parasitoides (Hym., Braconidae, Aphidiinae). Sin embargo, no parece que la abundancia de éstos fuera la suficiente para mantener las poblaciones de pulgones por debajo de los niveles considerados molestos.
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Data concerning the effect of temperature on different physiological parameters of an invasive species can be a useful tool to predict its potential distribution range through the use of modelling approaches. In the case of the Argentine ant these data are too scarce and incomplete. The aim of the present study is to compile new data regarding the effect of temperature on the oviposition rate of the Argentine ant queens. We analysed the oviposition rate of queens at twelve controlled temperatures, ranging from 10ºC to 34ºC under different monogynous and polygynous conditions. The oviposition rate of the Argentine ant queens is affected by temperature in the same manner, independently of the number of queens in the nest. The optimal temperature for egg laying was 28ºC, and its upper and lower limits depended on the degree of polygyny
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Many bird species produce two annual broods during a single breeding season. However, not all individuals reproduce twice in the same year suggesting that double brooding is condition-dependent. In contrast to most raptors and owls, the barn owl Tyto alba produces two annual clutches in most worldwide distributed populations. Nevertheless, the determinants of double brooding are still poorly studied. We performed such a study in a Swiss barn owl population monitored between 1990 and 2014. The annual frequency of double brooding varied from 0 to 14% for males and 0 to 59% for females. The likelihood of double brooding was higher when individuals initiated their first clutch early rather than late in the season and when males had few rather than many offspring at the first nest. Despite the reproductive benefits of double brooding (single- and double-brooded individuals produced 3.97 +/- 0.11 and 7.07 +/- 0.24 fledglings, respectively), double brooding appears to be traded off against offspring quality because at the first nest double-brooded males produced poorer quality offspring than single-brooded males. This might explain why females desert their first mate to produce a second brood with another male without jeopardizing reproductive success at the first nest. Furthermore, the reproductive cycle being very long in the barn owl (120 d from start of laying to offspring independence), selection may have favoured behaviours that accelerate the initiation of a second annual brood. Accordingly, half of the double-brooded females abandoned their young offspring to look for a new partner in order to initiate the second breeding attempt, 9.48 d earlier than when producing the second brood with the same partner. We conclude that male and female barn owls adopt different reproductive strategies. Females have more opportunities to reproduce twice in a single season than males because mothers are not strictly required during the entire rearing period in contrast to fathers. A high proportion of male floaters may also encourage females to desert their first brood to re-nest with a new male who is free of parental care duties.
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In birds, parents adjust their feeding behaviour according to breeding duties, which ultimately may lead to seasonal adjustments in nutritional physiology and hematology over the breeding season. Although avian physiology has been widely investigated in captivity, few studies have integrated individual changes in feeding and physiological ecology throughout the breeding season in wild birds. To study relationships between feeding ecology and nutritional ecophysiology in Cory"s shearwater Calonectris diomedea, we weighed and took blood samples from 28 males and 19 females during the pre-laying, egg-laying, incubation, hatching and chick-rearing periods of the breeding season. In addition, we fitted 6 birds with geolocators to track their foraging movements throughout the reproductive period. Thus, we examined individual changes in (1) nutritional condition (biochemistry metabolites); (2) oxygen carrying capacity (hematology); and (3) feeding areas and foraging effort (stable isotopes and foraging movements). Geolocators revealed a latitudinal shift in main feeding areas towards more southern and more neritic waters throughout the breeding season, which is consistent with the steady increase in δ13C signatures in the blood. Geolocators also showed a decrease in foraging effort from egg-laying to hatching, reflecting the activity decrease associated with incubation duties. Plasma metabolites, body mass and oxygen carrying capacity were associated with temporal changes in nutritional state and foraging effort in relation to recovery after migration, egg formation, fasting shifts during incubation and chick provisioning. This study shows that combining physiological and ecological approaches can help us understand the influence of breeding duties on feeding ecology and nutritional physiology in wild birds.
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Submersed vegetation is a common feature in about 70% Pyrene an high mountain (>1500 m a.s.l.) lakes. Isoetids and soft-water elodeids are common elements of this underw ater flora and can form distinct vegetation units (i.e. patches of vegetation dominated by different species) within complex mosaics of vegetation in shallow waters (<7 m). Since is oetids exert a strong influence on sediment biogeochemistry due to high radial oxygen loss, we examined the small scale characteristics of the lake environment (water and sediment) associated to vegetation patches in order to ascertain potential functional differences among them. To do so, we characterised the species composition and biomass of the main vegetation units from 11 lakes, defined plant communities based on biomass data, and then related each community with sediment properties (redox and dissolved nutrient concentration in the pore water) and water nutrient concentration within plant canopy. We also characterised lake water and sediment in areas without vegetation as a reference. A total of twenty-one vegetation units were identified, ranging from one to five per lake. A cluster analysis on biomass species composition suggested seven different macrophyte communities that were named after the most dominant species:Nitella sp.,Potamogeton praelongus, Myriophyllum alterniflorum, Sparganium angustifolium , Isoetes echinospora,Isoetes lacustris and Carex rostrata . Coupling between macrophyte communities and their immediate environment (overlying water and sediment) was manifested mainly as variation in sediment redox conditions and the dominant form of inorganic nitrogen in pore-water. These effects depended on the specific compositi on of the community, and on the allocation between above- and belowground biomass, and could be predicted with a model relating the average and standard deviation of sediment redox potential from 0 down to -20 cm, across macrophyte communities. Differences in pore-water total dissolved phosphorus were related to the trophic state of the lakes. There was no correlation between sediment and water column dissolved nutrients. However, nitrate concentrations tended to be lower in the water overlaying isoetid communities, in apparent contradiction to the patterns of dissolved nitrates in the pore-water. These tendencies were robust even when comparing the water over laying communities within the same lake, thus pointing towards a potential effect of isoetids in reducing dissolved nitrogen in the lakes.
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En l’exercici de les funcions típiques de qualsevol activitat humana, l’home ha de prendre decisions d’un o altre tipus permanentment i aquesta situació porta afegit, per lo general risc i incertesa, el que compromet la qualitat i l’èxit de la decisió. Per ajudar i contrarestar aquesta situació, l’home ha desenvolupat a través del temps una diversitat d’eines que li permeten minimitzar el risc i la incertesa en la presa de decisions. La simulació és una d’aquestes eines. Mitjançant la seva aplicació no només s’aconsegueix la comesa anterior, sinó que també es minimitzen els costos involucrats en la decisió mitjançant un millor ús dels recursos, la disminució del temps emprat per a la seva realització i la minimització de les probabilitats de risc. Aquest projecte representa la continuació d’un primer estudi introductori de la simulació anomenat: Estudi i guia docent per a modelatge i simulació de sistemes mitjançant l’entorn ARENA [9]. Realitzat per l’alumna d’Enginyeria en Organització Industrial de la Universitat de Vic, Montse Carbonell Crosas, l’any 2008 i sota la codirecció del director d’aquest segon projecte, el professor Juli Ordeix Rigo. Aquest nou projecte s’inicia amb una primera part teòrica, continguda dins del primer volum, la qual reforça els conceptes teòrics referents a la simulació amb ARENA, ja vistos en l’anterior projecte. Complementant aquells considerats bàsics i els de més utilitat i finalitza introduint nous conceptes avançats. Els nous capítols de temàtica avançada, junt als primers més bàsics de la primera part són exercitats dins de la segona, formant el segon volum d’aquest projecte. El mateix requereix la participació activa de l’alumne, per tal de realitzar cadascun dels 89 exercicis pràctics que es plantegen i poder onsolidar l’aprenentatge teòric d’aquesta eina avançada de simulació fent consultes als apartats teòrics recomanats dins de cada exercici. La complexitat dels exercicis anirà augmentant gradualment i s’insisteix en seguir la metodologia presentada en el projecte per a realitzar-los tots de forma ordenada i ascendent. L’ alumne quan acabi la part pràctica, haurà consolidat tota la part teòrica i serà capaç d’exercir com analista per tal de generar els seus propis projecte de simulació.
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In this paper I provide a concise plan about Hegel's Lectures on the Philosophy of Religion critical editions, laying stress on the method followed by editors in order to build a coherent text with the sources at their disposal. The Marheineke's edition (1832) is analysed with special attention since it was the edition that caused the division between a Right and a Left, opening the discussion on speculative theism as a consequence of the difficulty to distinguish the systematic part from the historical one in the reasoning carried out by Hegel.
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Henhouse thermal comfort and bird age influence broiler breeder hen productivity; this way, the present research aimed to assess thermal comfort indexes and broiler breeder hen performance during winter in North East semi-arid region from Brazil, using a Cobb Avian 48 broiler strain at the age of 38 and 50 weeks. We measured the following bioclimatic indexes: air temperature and relative humidity, black globe temperature and humidity, CO2 concentration and sound pressure levels at henhouse facility. Data analysis design was complete randomized in a 3 x 3 factorial scheme with three treatments (months) and three replications (week number of collection by month). A number of 25 climatic data were observed. Bioclimatic indexes at the most warm hours throughout the day promoted bird discomfort yet sound pressure and carbon dioxide levels were under the Brazilian standards. Even in thermal comfort zone at some hours, the productivity indexes were in compliance with those recommended by the strain creation guidebook.