Outcrossing rate of Couratari multiflora (J.Smith) Eyma (Lecythidaceae), a low-density tropical tree species from a central Amazonian rainforest

A multilocus mixed-mating model was used to evaluate the mating system of a population of Couratari multiflora, an emergent tree species found in low densities (1 individual/10 ha) in lowland forests of central Amazonia. We surveyed and observed phenologically 41 trees in an area of 400 ha. From these, only four mother trees were analyzed here because few of them set fruits, which also suffered high predation. No difference was observed between the population multilocus outcrossing rate (t mp = 0.953 ± 0.040) and the average single locus rate (t sp = 0.968 ± 0.132). The four mother trees were highly outcrossed (t m ~ 1). Two out of five loci showed departures from the Hardy-Weinberg Equilibrium (HWE) expectations, and the same results occurred with the mixed-mating model. Besides the low number of trees analyzed, the proportion of loci in HWE suggests random mating in the population. However, the pollen pool was heterogeneous among families, probably due to both the small sample number and the flowering of trees at different times of the flowering season. Reproductive phenology of the population and the results presented here suggest, at least for part of the population, a long-distance pollen movement, around 1,000 m.

Density, size and distribution of stomata in 35 rainforest tree species in Central Amazonia

Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p < 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.

Tree communities of white-sand and terra-firme forests of the upper Rio Negro

The high tree diversity and vast extent of Amazonian forests challenge our understanding of how tree species abundance and composition varies across this region. Information about these parameters, usually obtained from tree inventories plots, is essential for revealing patterns of tree diversity. Numerous tree inventories plots have been established in Amazonia, yet, tree species composition and diversity of white-sand and terra-firme forests of the upper Rio Negro still remain poorly understood. Here, we present data from eight new one-hectare tree inventories plots established in the upper Rio Negro; four of which were located in white-sand forests and four in terra-firme forests. Overall, we registered 4703 trees > 10 cm of diameter at breast height. These trees belong to 49 families, 215 genera, and 603 species. We found that tree communities of terra-firme and white-sand forests in the upper Rio Negro significantly differ from each other in their species composition. Tree communities of white-sand forests show a higher floristic similarity and lower diversity than those of terra-firme forests. We argue that mechanisms driving differences between tree communities of white-sand and terra-firme forests are related to habitat size, which ultimately influences large-scale and long-term evolutionary processes.

Biological and morphometric aspects and rearing of Syssphinx molina (Cramer) (Lepidoptera: Saturniidae), a defoliator of parica tree

The objective of this research was to describe the biological and morphometric aspects of the parica tree defoliator, Syssphinx molina (Cramer), and make recommendations about the insect rearing. The life cycle was 62.9 days with mean periods for the egg, larval, pre-pupal and pupal stages of 5.6, 31.1, 2.2 and 16.6 days respectively. The pupal viability was 60.5% for females and 48.6% for males. The sexual ratio was 0.5 with mean production of 182.3 ± 2.2 eggs per female and egg viability of 24.3%. The mean longevity was 7.9 ± 2 and 8.1 ± 3 days for females and males respectively. Other parameters were also observed and compared with description of other Saturniidae species.

Updated List and identification key of 219 tree species of white sand forests of the Allpahuayo Mishana National Reserve, Loreto, Peru

White sand forests, although low in nutrients, are characterized not only by several endemic species of plants but also by several monodominant species. In general, plants in this forest have noticeably thin stems. The aim of this work was to elaborate a parallel dichotomous key for the identification of Angiosperm tree species occurring on white sand forests at the Allpahuayo Mishana National Reserve, Loreto, Peru. We compiled a list of species from several publications in order to have the most comprehensive list of species that occur on white sand forest. We found 219 species of Angiosperm, the more abundant species were Pachira brevipes (26.27%), Caraipa utilis (17.90%), Dicymbe uaiparuensis (13.27%), Dendropanax umbellatus (3.28%), Sloanea spathulata (2.52%), Ternstroemia klugiana (2.30%), Haploclathra cordata (2.28%), Parkia igneiflora (1.20%), Emmotum floribundum (1.06%), Ravenia biramosa (1.04%) among others. Most species of white sand forests can be distinguished using characteristics of stems, branches and leaves. This key is very useful for the development of floristic inventories and related projects on white sand forests from Allpahuayo Mishana National Reserve.

Predicting the distribution of forest tree species using topographic variables and vegetation index in eastern Acre, Brazil

Species distribution modeling has relevant implications for the studies of biodiversity, decision making about conservation and knowledge about ecological requirements of the species. The aim of this study was to evaluate if the use of forest inventories can improve the estimation of occurrence probability, identify the limits of the potential distribution and habitat preference of a group of timber tree species. The environmental predictor variables were: elevation, slope, aspect, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). To estimate the distribution of species we used the maximum entropy method (Maxent). In comparison with a random distribution, using topographic variables and vegetation index as features, the Maxent method predicted with an average accuracy of 86% the geographical distribution of studied species. The altitude and NDVI were the most important variables. There were limitations to the interpolation of the models for non-sampled locations and that are outside of the elevation gradient associated with the occurrence data in approximately 7% of the basin area. Ceiba pentandra (samaúma), Castilla ulei (caucho) and Hura crepitans (assacu) is more likely to occur in nearby water course areas. Clarisia racemosa (guariúba), Amburana acreana (cerejeira), Aspidosperma macrocarpon (pereiro), Apuleia leiocarpa (cumaru cetim), Aspidosperma parvifolium (amarelão) and Astronium lecointei (aroeira) can also occur in upland forest and well drained soils. This modeling approach has potential for application on other tropical species still less studied, especially those that are under pressure from logging.

Fine time scaling of purifying selection on human nonsynonymous mtDNA mutations based on the worldwide population tree and mother-child pairs

A high-resolution mtDNA phylogenetic tree allowed us to look backward in time to investigate purifying selection. Purifying selection was very strong in the last 2,500 years, continuously eliminating pathogenic mutations back until the end of the Younger Dryas (∼11,000 years ago), when a large population expansion likely relaxed selection pressure. This was preceded by a phase of stable selection until another relaxation occurred in the out-of-Africa migration. Demography and selection are closely related: expansions led to relaxation of selection and higher pathogenicity mutations significantly decreased the growth of descendants. The only detectible positive selection was the recurrence of highly pathogenic nonsynonymous mutations (m.3394T>C-m.3397A>G-m.3398T>C) at interior branches of the tree, preventing the formation of a dinucleotide STR (TATATA) in the MT-ND1 gene. At the most recent time scale in 124 mother-children transmissions, purifying selection was detectable through the loss of mtDNA variants with high predicted pathogenicity. A few haplogroup-defining sites were also heteroplasmic, agreeing with a significant propensity in 349 positions in the phylogenetic tree to revert back to the ancestral variant. This nonrandom mutation property explains the observation of heteroplasmic mutations at some haplogroup-defining sites in sequencing datasets, which may not indicate poor quality as has been claimed.

Análise de Cluster e Análise Heurística na construção de uma tipologia de alcoolistas

Objetivos Desenvolver e avaliar uma tipologia binária de alcoolistas. Métodos Analisados registros de 329 alcoolistas acompanhados em estudo prospectivo e observacional. Análise de Correspondência foi aplicada para selecionar o menor número de variáveis capazes de representar a máxima variabilidade dos sujeitos; Análise de Cluster para identificar dois subtipos; e Análise Heurística para organizar as variáveis selecionadas em grupos de sentido. Análises Bivariadas foram utilizadas para testar possíveis associações com 51 variáveis demográficas ou clinicamente relevantes. Resultados A Análise de Correspondência selecionou 20 variáveis, posteriormente categorizadas em três grupos de sentidos por meio de Análise Heurística: “comportamentos”, “crenças” e “sentimentos”. Os pacientes do subgrupo 1 possuem perfil de maior gravidade clínica, psicopatológica e social. Sentimentos e crenças identificados se associaram a variáveis de consumo e recaída e os comportamentos com repercussão social. Conclusões Os resultados deste estudo permitem supor que a tipologia aqui apresentada possa contribuir para o tratamento desses subtipos de alcoolistas identificados por meio de estratégias teórico-práticas adaptadas às necessidades desses sujeitos.

Entrada de multinacionais num cluster e efeitos na estratégia das empresas instaladas

Dissertação de mestrado em Economia Industrial e da Empresa

Análisis y optimización del radio enlace de un sistema RFID y redes de sensores inalámbricos (WSN)

Un sistema inalámbrico en UHF puede ser utilizado tanto para la identificación de productos como para la adquisición de datos. Si se encuadra en la identificación se está refiriendo a sistemas “RFID” y si se encuadra en la adquisición de datos se está en presencia de una “Red de Sensores Inalámbrica”. El presente proyecto pretende desarrollar una plataforma de discusión permanente sobre estas tecnología que permita la optimización de los diferentes estamentos de la red. El proyecto tiene como objetivo general mejorar las prestaciones del vinculo entre los distintos elementos en un sistema RFID (Radio Frecuency Identification) o WSN (Wireless Sensor Network). En tal sentido, se propone en una primer línea de investigación, el desarrollo de un modelo que caracterice una red inalámbrica de sensores en UHF, permitiendo luego simularla bajo distintas condiciones. El objetivo es tener una herramienta con la cual se pueda estudiar y simular el comportamiento de una red con varios nodos. Una segunda línea de trabajo aborda el problema del test para sistemas RFID y WSN, con énfasis en nodos activos y pasivos diseñados con circuitos analógicos y digitales configurables y componentes comerciales. Así, se propone el desarrollo de estrategias de test de bajo consumo y alto desempeño focalizadas en las secciones analógicas, de conversión y digitales configurables del nodo. Los trabajos específicos planteados para responder a los objetivos que se pretenden son: La caracterización y modelado del enlace inalámbrico en UHF; La caracterización y modelado del transceptor en sus distintas etapas; La caracterización y modelado de la red con los distintos nodos; El estudio de nuevos diseños de antenas; El estudio de distintas adaptaciones de la etapa de RF con la antena; El estudio de alternativas de distintas modulaciones de las señales a transmitir; Proponer estrategias de simulación y/o emulación de fallas para sistemas analógicos y digitales que permita la evaluación de las estrategias de test y de los mecanismos de recuperación ante fallas; Evaluar el funcionamiento en laboratorio y en campo de los nodos y el lector

Anwendung der Coupled-Cluster-Methode zur Untersuchung frustrierter quasi-eindimensionaler und zweidimensionaler Quantenspinsysteme

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2010

Walking Tree - Organisation neuer Forschung in der Wissenschaft : Zusammenarbeit zwischen Integration und Differenzierung

Magdeburg, Univ., Fak. für Geistes-, Sozial- und Erziehungswiss., Diss., 2011

Quantum phase transitions in magnetic systems: application of coupled cluster method

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2009

Förderung von Gewerbeneuansiedlungen im Wirtschaftsraum Blankenburg (Harz) unter Berücksichtigung der bestehenden gewerblichen Cluster

Ziel der Arbeit war es, den Wirtschaftsraum Blankenburg (Harz) durch die Bildung und Förderung von gewerblichen Clustern attraktiver zu gestalten. In diesem Rahmen wurde zunächst die Entwicklung von Gewerbe- und Industrieflächen mithilfe der Bauleitplanung in Theorie und Praxis beschrieben. Die anschließende Untersuchung des Bundeslandes Sachsen-Anhalt und im speziellen der Stadt Blankenburg (Harz) bildeten die Datengrundlage für die weiteren Arbeitsschritte. Um die Ergebnisse dieser Standortanalyse in einen direkten Zusammenhang mit tatsächlichen Eindrücken der ansässigen Unternehmen bringen zu können, wurde eine schriftliche Unternehmensbefragung durchgeführt. Diese thematisierte vor allem die Einschätzung der Standortfaktoren in Blankenburg (Harz). Die im Zwischenfazit beschriebene Wertung, dass die Stadt derzeit nur wenige Anreize für Unternehmensneuansiedlungen bietet, war Ausgangspunkt für die Theorie der Clusterpolitik. Dabei wurden zunächst gewerbliche Cluster aus den ansässigen Unternehmen gebildet. Daraus resultierten die Wirtschaftsbereiche, deren Unternehmen für eine Ansiedlung in Blankenburg besonders in Frage kommen. Da diese Betriebe feste Anforderungen an Gewerbe- oder Industrieflächen in Bezug auf die Größe, die planungsrechtlichen Beschränkungen und die infrastrukturelle Anbindung stellen, konnten die vorhandenen Freiflächen im Rahmen einer Mikroanalyse hinsichtlich ihrer Eignung für Neuansiedlungen untersucht werden.

Species richness and community structure of arboreal spider assemblages in fragments of three vegetational types at Banhado Grande wet plain, Gravataí River, Rio Grande do Sul, Brazil

The taxonomic composition, observed and estimated species richness, and patterns of community structure of arboreal spider assemblages in eleven sites surrounding the "Banhado Grande" wet plain in the state of Rio Grande do Sul, Brazil, are presented. These sites represent three different vegetational types: hillside (four sites), riparian (five sites) and flooded forests (two sites). The spiders were captured by beating on foliage and "aerial litter". A sample was defined as the result of beating on twenty bushes, tree branches or "aerial litter" clusters, which roughly corresponds to one-hour search effort per sample. Fifty five samples (five per site) were obtained, resulting in an observed richness of 212 species present as adult or identifiable juveniles. The total richness for all samples was estimated to be between 250 (Bootstrap) to 354 species (Jackknife 2). Confidence intervals of both sample and individual-based rarefaction curves for each vegetation type clearly indicated that flooded forest is the poorest vegetation type with respect to spider species richness, with hillside and riparian forests having a similar number of species. The percentage complementarity between the eleven sites indicated that all sites contain a distinct set of species, irrespective of their vegetation types. Nevertheless, the spider assemblages in riparian and hillside forests are more similar with respect to each other than when compared to flooded forest. Both cluster and nonmetric multidimensional scaling analyses showed no strong correspondence between the spider arboreal fauna and the three vegetation types. Moreover, a Mantel test revealed no significant association between species composition and geographic distance among sites.