Showing papers by "State University of Campinas published in 2000"

Plant Physiological Ecology

Abstract: -- Plant Science The growth, reproduction and geographical distribution of plants are profoundly influenced by their physiological ecology: the interaction with the surrounding physical, chemical and biological environments. This textbook is notable in emphasizing that the mechanisms underlying plant physiological ecology can be found at the levels of biochemistry, biophysics, molecular biology and whole-plant physiology. At the same time, the integrative power of physiological ecology is well-suited to assess the costs, benefits and consequences of modifying plants for human needs, and to evaluate the role of plants in ecosystems. Plant Physiological Ecology begins with the primary processes of carbon metabolism and transport, plant-water relations, and energy balance. After considering individual leaves and whole plants, these physiological processes are then scaled up to the level of the canopy. Subsequent chapters discuss mineral nutrition and the ways in which plants cope with nutrient-deficient or toxic soils. The book then looks at patterns of growth and allocation, life-history traits, and interactions between plants and other organisms. Later chapters deal with traits that affect decomposition of plant material and with plant physiological ecology at the level of ecosystems and global environmental processes. Plant Physiological Ecology features numerous boxed entries that provide extended discussions of selected issues, a glossary, and numerous references to the primary and review literature. The significant new text is suitable for use in plant ecology courses, as well as classes ranging from plant physiology to plant molecular

Potential applications of oxidative enzymes and phenoloxidase-like compounds in wastewater and soil treatment: a review

Abstract: A number of oxidative enzymes from bacteria, fungi and plants have been reported to play an important role in numerous waste treatment applications. Peroxidases and/or phenoloxidases can act on specific recalcitrant pollutants by precipitation or transforming to other products and permitting a better final treatment of the waste. Improvement in the useful life and thereby a reduction in treatment cost has been accomplished through enzyme immobilization. Horseradish peroxidase, lignin peroxidase and manganese peroxidase mineralize a variety of recalcitrant aromatic compounds. Immobilization of these enzymes on porous ceramic supports or resins did not adversely affect their stability and showed a good potential for degradation of environment persistent aromatics. Tyrosinase, which catalyzes the hydroxylation of phenols and dehydrogenation of o-diphenols, in an immobilized form exerted an excellent phenol removal. Laccase is capable of eliminating the phenols through polymerization process, however, the presence of mediator such as ABTS and HBT degraded phenol by oxidative process. Many applications with oxidative enzymes and plant materials in effluent as in soil remediation will be discussed.

The genome sequence of the plant pathogen Xylella fastidiosa

Abstract: Instituto Ludwig de Pesquisa sobre o Câncer, Rua Prof. Antonio Prudente, 109-4 andar, 01509-010, Sao Paulo-SP

Electric power system state estimation

Abstract: This paper discusses the state of the art in electric power system state estimation. Within energy management systems, state estimation is a key function for building a network real-time model. A real-time model is a quasi-static mathematical representation of the current conditions in an interconnected power network. This model is extracted at intervals from snapshots of real-time measurements (both analog and status). The new modeling needs associated with the introduction of new control devices and the changes induced by emerging energy markets are making state estimation and its related functions more important than ever.

Output feedback control of Markov jump linear systems in continuous-time

Abstract: This paper addresses the dynamic output feedback control problem of continuous-time Markovian jump linear systems. The fundamental point in the analysis is an LMI characterization, comprising all dynamical compensators that stabilize the closed-loop system in the mean square sense. The H/sub 2/ and H/sub /spl infin//-norm control problems are studied, and the H/sub 2/ and H/sub /spl infin// filtering problems are solved as a by product.

Signature of atomic structure in the quantum conductance of gold nanowires.

Abstract: We have used high resolution transmission electron microscopy to determine the structure of gold nanowires generated by mechanical stretching. Just before rupture, the contacts adopt only three possible atomic configurations, whose occurrence probabilities and quantized conductance were subsequently estimated. These predictions have shown a remarkable agreement with conductance measurements from a break junction operating in ultrahigh vacuum, corroborating the derived correlation between nanowire atomic structure and conductance behavior.

An evolutionary immune network for data clustering

Abstract: This paper explores basic aspects of the immune system and proposes a novel immune network model with the main goals of clustering and filtering unlabelled numerical data sets. It is not our concern to reproduce with confidence any immune phenomenon, but to show that immune concepts can be used to develop powerful computational tools for data processing. As important results of our model, the network evolved will be capable of reducing redundancy, describing data structure, including the shape of the clusters. The network will be implemented in association with a statistical inference technique, and its performance will be illustrated using two benchmark problems. The paper is concluded with a trade-off between the proposed network and artificial neural networks used to perform unsupervised learning.

An ultra-fast user-steered image segmentation paradigm: live wire on the fly

Abstract: The authors have been developing general user steered image segmentation strategies for routine use in applications involving a large number of data sets. In the past, they have presented three segmentation paradigms: live wire, live lane, and a three-dimensional (3-D) extension of the live-wire method. Here, they introduce an ultra-fast live-wire method, referred to as live wire on the fly for further reducing user's time compared to the basic live-wire method. In live wire, 3-D/four-dimensional (4-D) object boundaries are segmented in a slice-by-slice fashion. To segment a two-dimensional (2-D) boundary, the user initially picks a point on the boundary and all possible minimum-cost paths from this point to all other points in the image are computed via Dijkstra's algorithm. Subsequently, a live wire is displayed in real time from the initial point to any subsequent position taken by the cursor. If the cursor is close to the desired boundary, the live wire snaps on to the boundary. The cursor is then deposited and a new live-wire segment is found next. The entire 2-D boundary is specified via a set of live-wire segments in this fashion. A drawback of this method is that the speed of optimal path computation depends on image size. On modestly powered computers, for images of even modest size, some sluggishness appears in user interaction, which reduces the overall segmentation efficiency. In this work, the authors solve this problem by exploiting some known properties of graphs to avoid unnecessary minimum-cost path computation during segmentation. In live wire on the fly, when the user selects a point on the boundary the live-wire segment is computed and displayed in real time from the selected point to any subsequent position of the cursor in the image, even for large images and even on low-powered computers. Based on 492 tracing experiments from an actual medical application, the authors demonstrate that live wire on the fly is 1.331 times faster than live wire for actual segmentation for varying image sizes, although the pure computational part alone is found to be about 120 times faster.

Shotgun sequencing of the human transcriptome with ORF expressed sequence tags

Abstract: Theoretical considerations predict that amplification of expressed gene transcripts by reverse transcription-PCR using arbitrarily chosen primers will result in the preferential amplification of the central portion of the transcript. Systematic, high-throughput sequencing of such products would result in an expressed sequence tag (EST) database consisting of central, generally coding regions of expressed genes. Such a database would add significant value to existing public EST databases, which consist mostly of sequences derived from the extremities of cDNAs, and facilitate the construction of contigs of transcript sequences. We tested our predictions, creating a database of 10,000 sequences from human breast tumors. The data confirmed the central distribution of the sequences, the significant normalization of the sequence population, the frequent extension of contigs composed of existing human ESTs, and the identification of a series of potentially important homologues of known genes. This approach should make a significant contribution to the early identification of important human genes, the deciphering of the draft human genome sequence currently being compiled, and the shotgun sequencing of the human transcriptome.

Diversity of plant uses in two Caiçara communities from the Atlantic Forest coast, Brazil

Abstract: Caicaras are native inhabitants of the Atlantic coast on southeastern Brazil, whose subsistence is based especially on agriculture and artisanal fishing. Because of their knowledge about the environment acquired through generations, Caicara people can play an important role in Atlantic Forest conservation. An ethnobotanical study was conducted within two Caicara communities (Ponta do Almada and Camburi beach, Sao Paulo State, Brazil), focusing on plant uses. In 102 interviews, 227 plant ethnospecies were quoted, mainly for food, medicine, handicraft and construction of houses and canoes. People from studied communities depend on the native vegetation for more than a half of the species known and used. Using diversity indices, plant uses are compared between studied communities and between gender and age categories within each community. We found quantitative differences in the knowledge about plants between gender categories for each kind of use (medicinal, food and handicrafts). Older and younger informants also have different knowledge about plants for handicraft and medicine, but not for edible plants.

A checklist of arthropods associated with pig carrion and human corpses in Southeastern Brazil

Abstract: Necrophagous insects, mainly Diptera and Coleoptera, are attracted to specific stages of carcass decomposition, in a process of faunistic succession. They are very important in estimating the postmortem interval, the time interval between the death and the discovery of the body. In studies done with pig carcasses exposed to natural conditions in an urban forest (Santa Genebra Reservation), located in Campinas, State of Sao Paulo, southeastern Brazil, 4 out of 36 families of insects collected - Calliphoridae, Sarcophagidae, Muscidae (Diptera) and Dermestidae (Coleoptera) - were considered of forensic importance, because several species were collected in large numbers both visiting and breeding in pig carcasses. Several species were also observed and collected on human corpses at the Institute of Legal Medicine. The species belonged to 17 different families, 6 being of forensic importance because they were reared from human corpses or pig carcasses: Calliphoridae, Sarcophagidae, Muscidae, Piophilidae (Diptera), Dermestidae, Silphidae and Cleridae (Coleoptera). The most important species were: Diptera - Chrysomya albiceps, Chrysomya putoria, Hemilucilia segmentaria, Hemilucilia semidiaphana (Calliphoridae), Pattonella intermutans (Sarcophagidae), Ophyra chalcogaster (Muscidae), Piophila casei (Piophilidae); Coleoptera - Dermestes maculatus (Dermestidae), Oxyletrum disciolle (Silphidae) and Necrobia rufipes (Cleridae).

Saúde pública e saúde coletiva: campo e núcleo de saberes e práticas

Abstract: O artigo discute o campo e o nucleo de saberes e de praticas da saude coletiva a partir de um metodologia dialetica, pensando-a para alem do positivismo e do estruturalismo e fazendo uma critica a sua tendencia de assumir posicao de transcendencia sobre o campo da saude. A partir dessa analise sao elaboradas sugestoes para debate, relacionadas centralmente com saude coletiva entendida como construcao sociohistorica de sujeitos concretos.

Biochemical composition and cariogenicity of dental plaque formed in the presence of sucrose or glucose and fructose.

Abstract: The composition of dental plaque formed in the presence of sucrose or glucose and fructose and its relation to cariogenicity was evaluated. Twelve adult volunteers took part in this crossover study do

Tabu search algorithm for network synthesis

Abstract: Large scale combinatorial problems such as the network expansion problem present an amazingly high number of alternative configurations with practically the same investment, but with substantially different structures (configurations obtained with different sets of circuit/transformer additions). The proposed parallel tabu search algorithm has shown to be effective in exploring this type of optimization landscape. The algorithm is a third generation tabu search procedure with several advanced features. This is the most comprehensive combinatorial optimization technique available for treating difficult problems such as the transmission expansion planning. The method includes features of a variety of other approaches such as heuristic search, simulated annealing and genetic algorithms. In all test cases studied there are new generation, load sites which can be connected to an existing main network: such connections may require more than one line, transformer addition, which makes the problem harder in the sense that more combinations have to be considered.

Ferromagnetic- and Superconducting-like Behavior of Graphite

Abstract: We have identified ferromagnetic- and superconducting-like magnetization hysteresis loops in highly oriented pyrolytic graphite samples below and above room temperature. We also found that both behaviors are very sensitive to low-temperature—as compared to the sample synthesis temperature—heat treatment. The possible contribution of magnetic impurities and why these do not appear to be the reason for the observed phenomena is discussed.

Behaviourally driven gene expression reveals song nuclei in hummingbird brain

Abstract: Hummingbirds have developed a wealth of intriguing features, such as backwards flight, ultraviolet vision, extremely high metabolic rates, nocturnal hibernation, high brain-to-body size ratio and a remarkable species–specific diversity of vocalizations1,2,3,4. Like humans, they have also developed the rare trait of vocal learning, this being the ability to acquire vocalizations through imitation rather than instinct5,6. Here we show, using behaviourally driven gene expression in freely ranging tropical animals, that the forebrain of hummingbirds contains seven discrete structures that are active during singing, providing the first anatomical and functional demonstration of vocal nuclei in hummingbirds. These structures are strikingly similar to seven forebrain regions that are involved in vocal learning and production in songbirds and parrots7,8,9,10,11,12,13—the only other avian orders known to be vocal learners5. This similarity is surprising, as songbirds, parrots and hummingbirds are thought to have evolved vocal learning and associated brain structures independently5,14, and it indicates that strong constraints may influence the evolution of forebrain vocal nuclei.

Atlantic Forest Butterflies: Indicators for Landscape Conservation1

Abstract: The Atlantic Forest region (wide sense) includes very complex tropical environments, increasingly threatened by extensive anthropogenic conversion (>90%). Ecologically specialized, short-generation insects (butterflies) are evaluated here as indicators for monitoring community richness, landscape integrity, and sustainable resource use in the region. The > 2100 butterfly species in the Atlantic Forest region have been censused in many sites over 35 years, giving comparable daily, weekly, monthly, and long-term site lists. The 21 most thoroughly studied sites include 218–914 species, of which half can be censused in a week or less. The butterfly communities are divided into six relatively distinct faunal regions, centered in the northeast, the central coastal tablelands, the southeast coastal plain, the mountains plus interior of the southeastern states, the central plateau, and the southern states. Species richness shows the highest values in coastal mountains from 15 to 23°S. Local butterfly com...

Estimating nanoparticle size from diffraction measurements

Abstract: Nanometre-sized particles are of considerable current interest because of their special size-dependent physical properties. Debye–Scherrer diffraction patterns are often used to characterize samples, as well as to probe the structure of nanoparticles. Unfortunately, the well known `Scherrer formula' is unreliable at estimating particle size, because the assumption of an underlying crystal structure (translational symmetry) is often invalid. A simple approach is presented here which takes the Fourier transform of a Debye–Scherrer diffraction pattern. The method works well on noisy data and when only a narrow range of scattering angles is available.