Rio Claro - IB - Instituto de Biociências

URI Permanente para esta coleçãohttps://hdl.handle.net/11449/253838

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Plant Response to Toxic Metals: Emerging Sources, Phytohormone Role, and Tolerance Responses
(2023-01-01) Gavassi, Marina Alves ; de Oliveira Carvalho, Brenda Mistral ; Bressan, Anna Carolina Gressler ; Habermann, Gustavo ; Universidade Estadual Paulista (UNESP)
The availability of toxic metals in the soil system is an important limiting factor for global crop productivity, being considered a major threat to food security. In the last years, vast areas of arable land around the world have been polluted by toxic heavy metals such as arsenic (As), cadmium (Cd), and lead (Pb), and the high accumulation of these elements in edible plants is causing severe damages to the health of humans and animals. Soil acidification, for many reasons, can turn the most abundant metal in the soil, aluminum (Al), also toxic for plants. A large number of different transporters, enzymes, and ligands, as well as their related genes, which play an important role in uptake, translocation, subcellular compartmentalization, and detoxification of different toxic metals, have been implicated in how plants respond and survive. Between metal perception and response, multiple signaling pathways are triggered, in which hormone participation has been evidenced and clarified. In this chapter, we provide an overview about the interaction between the main molecular components shared between major toxic metal(loid)s, such as As, Cd, Pb, and Al, and plant hormone pathways, focusing on abscisic acid (ABA), discussing interesting topics which raise perspectives for plant tolerance bioengineering.
Metabolic engineering as a tool for biosurfactant production by microorganisms
(2023-06-13) Lovaglio, Roberta Barros ; da Silva, Vinícius Luiz ; Contiero, Jonas ; Universidade Federal de São Carlos (UFSCar) ; MicroGreen-Soluções Biotecnológicas ; Universidade Estadual Paulista (UNESP)
Biosurfactants produced by microorganisms are products with excellent physicochemical properties in addition to being produced from renewable sources and presenting low toxicity and environmental compatibility. Despite their advantages, they are still not widely produced on an industrial scale, due to the high production costs. Metabolic engineering tools have contributed to bypassing this hurdle in different ways, such as the metabolic flux deviation or heterologous expression of genes associated with the synthesis of these compounds. This chapter deals with different strategies of metabolic engineering, which can support the establishment of biosurfactants on the market.
Post-embryonic development in Brazilian Social Wasps
(2020-11-07) Giannotti, Edilberto ; da Rocha, Agda Alves ; Universidade Estadual Paulista (UNESP) ; Universidade Federal da Bahia (UFBA)
This chapter presents a review of morphological studies of the immature stages of social Brazilian wasps, discussing aspects such as oviposition; instar larva, pre-pupa, and pupal stages; as well as duration times of the immature stages. Those themes have been explored in less than 20% of the species recorded for that country. Most of those articles represent only descriptions of the last instar larva, so that there is still much to explore in terms of comparative studies.
Natural attenuation of soil with biodiesel and its potential ecotoxicological impacts
(2022-08-10) Dilarri, Guilherme ; Mendes, Carolina Rosai ; de Moraes Ruy Sapata, Vinícius ; Tamada, Ivo Shodji ; Lopes, Paulo Renato Matos ; Montagnolli, Renato Nallin ; Bidoia, Ederio Dino ; Universidade Estadual Paulista (UNESP) ; Universidade Federal de São Carlos (UFSCar)
Petroleum and its derivatives cause numerous toxicity-related impacts on the environment. The evaluation of such impacts can promote adequate treatments of oil-based residues. A better understanding of the degradation of hydrocarbons aids researchers to predict the environmental impacts and the biodegradation processes that yield decreased toxicity levels. However, petroleum derivatives are not the sole matter of concern. Another important discussion targeting the environmental behavior of biodiesel should be brought up. Soil microorganisms may improve the biodegradation of hydrocarbons due to their diversity and robust enzymatic apparatus during natural attenuation processes. Still, some compounds can have their negative impacts on biota evaluated according to three parameters: ecotoxicological potential in soil (i), specific biodegradation processes (ii), and post-treatment bioassays (iii). This review presents how microbial biodegradation may ultimately affect the overall degradation of hydrocarbons.
Causes and consequences of large-scale defaunation in the Atlantic Forest
(2021-01-13) Galetti, Mauro ; Gonçalves, Fernando ; Villar, Nacho ; Zipparro, Valesca B. ; Paz, Claudia ; Mendes, Calebe ; Lautenschlager, Laís ; Souza, Yuri ; Akkawi, Paula ; Pedrosa, Felipe ; Bulascoschi, Letícia ; Bello, Carolina ; Sevá, Anaiá P. ; Sales, Lilian ; Genes, Luísa ; Abra, Fernanda ; Bovendorp, Ricardo S. ; Universidade Estadual Paulista (UNESP) ; University of Miami ; University of Cambridge ; Netherlands Institute for Ecology NIOO-KNAW ; Swiss Federal Research Institute WSL ; Santa Cruz State University ; Universidade Estadual de Campinas (UNICAMP) ; Stanford University ; Universidade de São Paulo (USP)
The Atlantic Forest of South America hosts one of the world's most diverse and threatened tropical forest biota. After five centuries of European human expansion, most Atlantic Forest landscapes are archipelagos of small forest fragments surrounded by open-habitat matrices. In this chapter, we describe the causes and consequences of large-scale defaunation in the Atlantic Forest of South America. We identify and quantify the magnitude of the main anthropogenic drivers of defaunation and stimulate a debate on how to revert the loss of fauna to restore biodiversity and ecosystem functions and services. The magnitude of the impact of defaunation in the Atlantic Forest is hard to estimate, but we can predict that, at large scale, habitat loss, fragmentation, and degradation are the most common threats to terrestrial populations. Other threats vary in importance according to the taxonomic group. In general, apex predators, other carnivores, large-bodied mammals, and large herbivores were among the most defaunated functional groups and the loss of these animals has also a strong impact on the ecosystem services. Given the extent of the consequences of defaunation in the Atlantic Forest, mitigation strategies are imperative. Habitat restoration would clearly be effective in building space for defaunation mitigation but reversing the pervasive defaunation that occurred in the Atlantic Forest is by no means a straightforward task. Nonetheless, it will be fundamental to assure the persistence of the biodiversity in the Atlantic Forest remnants.
Dealing with fragmentation and road effects in highly degraded and heterogeneous landscapes
(2016-04-11) Ribeiro, Milton Cezar ; de Lara Muylaert, Renata ; Dodonov, Pavel ; Ciocheti, Giordano ; Magioli, Marcelo ; Martello, Felipe ; Rocha, Alessandro ; Borges, Bruno Defane ; Carvalho, Carolina ; Kanda, Claudia Zukeran ; Rodriguez-Castro, Karen G. ; Universidade Estadual Paulista (UNESP) ; Ecology Applied to Conservation Laboratory ; Universidade de São Paulo (USP) ; Universidade Federal de São Carlos (UFSCar)
Polyhydroxyalkanoates: Naturally occurring microbial polymers suitable for nanotechnology applications
(2021-01-01) De Paula-Elias, Fabrício C. ; De Paula, Carolina B. C. ; De Oliveira, Nayra M. L. ; De Almeida, Alex F. ; Contiero, Jonas ; Federal University of Tocantins ; Universidade Estadual Paulista (UNESP)
Polyhydroxyalkanoates (PHAs) are intracellular microbial polyesters synthesized by many species of Bacteria and Archaea, generally under nutrient limitation and excess of carbon source as storage granules of energy and also conferring stress resistance to prokaryotes. PHAs are naturally occurring, and the choice of microbial strains and carbon sources for cell cultivations results in biopolymers with different physicochemical properties. Cupriavidus necator is a bacterial strain able to synthesize a high crystalline polymer, poly(3-hydroxybutyrate), the most common of all PHAs; whereas Pseudomonas species produce PHAs with medium chain-length monomers, which exhibit elastomeric properties as natural rubbers. This variety of monomer composition associated with high biocompatibility and biodegradability makes PHAs also feasible for compostable applications and meet the standard specification for marine degradability. Due to their high versatility as natural chemicals and their ecologically friendly properties, PHAs have drawn attention for a wide range of applications from which the PHA nanocomposites have become a promising alternative to petrochemical polymers for nanoscale applications, especially those involved in biomedical materials. This review chapter introduces PHAs from their microbial synthesis, polymer structure to recent applications, with special focus on nanoscience applications. PHA as scaffolds for tissue engineering, nanofibers and particles for catalyst immobilization and drug delivery systems are topics addressed in this chapter. Finally, the future prospects and economical challenges to be overcome by the PHA industry are discussed in this review chapter from a green chemistry background.
History of inclusive physical education in South America
(2019-12-06) Mauerberg-deCastro, Eliane ; Campbell, Debra Frances ; Universidade Estadual Paulista (UNESP)
We examined how the origins of education and special education have influenced inclusion in schools and in physical education (PE) in the South American region. National and constitutional legislation in every country in the region has followed international recommendations (e.g., the many campaigns and directives from the United Nations and others), which, therefore, has helped to reform school curricula provisions and bylaws for the inclusive education of people with disability (PWD). However, for these countries, the reality of opportunities for education in general has evolved in unique directions due to the political and cultural influences of their institutions, educators and societies in general. Pedagogic practices for successful inclusion in schools are still unknown in the region. The statistics of some countries show an increase in enrolment rates over the course of decades after educational reforms had taken place. Lack of accountability for ensuring school retention and achievement for PWD has resulted in a negatively biased perception of the value of inclusive settings. As for PE in regular schools, teachers who are unprepared and potentially confused about how to merge rehabilitation procedures with pedagogical practices reveal little evidence that the discipline has evolved in the region. Teacher preparation in PE higher education continues to include adapted physical education (APE) programmes designed for segregated settings: one for each disability.
Cultural factors currently affecting inclusive practice-South America
(2019-12-06) Mauerberg-deCastro, Eliane ; Campbell, Debra Frances ; Universidade Estadual Paulista (UNESP)
Despite economic and cultural diversity within each of the twelve countries and three regions of the South American continent, a common understanding of human rights policies guides the wider educational system, and, consequently, favours the inclusion movement in schools - in theory. The uniqueness of each country and even regional contrasts (e.g., Brazil, Uruguay, Chile, to name a few) are determinant factors as to whether effective inclusion in schools - successful school achievement - even exists. Perceptions of societal values (e.g., people’s attitudes and stereotypes) and institutional responsibilities (e.g., school policies and educators’ competencies) are deeply affected by the domination of 21st-century globalization and the technological ecosystem. Practices of inclusion in physical education (PE) are challenged by media-culture constraints (e.g., an epidemic state of obesity and physical inactivity in children and youngsters, body image distortions accompanied with an obsessive pursuit of the ideal body aesthetic) along with historical and cultural factors. Still, the modernization of resources and international accessibility to information are potential allies to inclusive practices and can have positive outcomes in the areas of development, rehabilitation, health and personal empowerment, to name a few.
Polyhydroxyalkanoates: A short tale from polymer synthesis to future prospects
(2018-01-01) de Paula, Fabrício C. ; de Paula, Carolina B. C. ; Contiero, Jonas ; Universidade Estadual Paulista (UNESP)
Polyhydroxyalkanoates (PHAs) are bacterial polyesters belonging to the most important group of bio-based and biodegradable polymers. A large number of bacteria possesses the ability to synthesize PHAs as carbon energy storage and a variety of monomer constituents of PHAs has been described, whose chemical composition range from straight to aromatic structures. The PHA synthesis is strongly influenced by the carbon source utilized for microbial growth and the metabolic pathways involved in the polymer synthesis, which the PHA synthase plays an essential role in the PHA polymerization process. This chapter introduces PHAs from their biochemical concept to a promising alternative for petrochemical compounds as eco-friendly thermoplastics. Among many suitable characteristics for industrial applications the most important attribute of PHAs is their biodegradability. The challenges faced by the industry of biopolymers in order to scaling-up the PHA production and increase their economical feasibility in the global market, including recent advances to minimize costs and to improve the polymer yield, besides the sustainable production of PHAs from agroindustrial by-products are also a focus of this review chapter.
Morphology like a tool to understand the social behavior in ant’s larvae
(2012-01-01) Ortiz, Gabriela ; Mathias, Maria Izabel Camargo ; Bueno, Odair Correa ; Universidade Estadual Paulista (UNESP)
All metamorphosing insects pass through four consecutive stages before reaching their adult form and these stages are known as the egg, the larva, the semipupa and the pupa. The larval stage comprising individuals who have completely different morphology of the other three, since the body is devoid of external appendages and with internally adipose tissue. From the larval stage begins the growth of individuals who shed their skins several times and depending on the insect considered the substages vary from 3 to 5. In bees in general there are five larval stages called L1 to L5, interspersed with each other for four periods of change ending in larval and pupal changes when successful-L5 larvae enter the pupal stage, where individuals have had adult characteristics. Since ants have about four larval stages (L1, L2, L3, L4), but this number can vary from 3 to 6 depending on the species. In the larvae of ants there are morphological peculiarities in certain species that set them apart from most reported in the literature so far. An interesting fact was observed in the Argentine ant Linepithema humile, an invasive species, since they present a dorsal protuberance in the sixth abdominal segment found exclusively in their larvae. Researchers have tried to explain the social function of this structure. One function described was the nutrition. However the morphological results obtained in this study suggested that the dorsal protuberance has no secretory function, since ducts or pore channels were not found, only small folds in the cuticle, which does not indicate a secretion release function. The secretion released is just for the cuticle compounds and does not synthesize other one which would be important in social behavior. Therefore the unique social function that can be attributed to the dorsal protuberance was mechanical or serving like a facilitator making it easier for the workers to transport the immatures through the different environments in the colony. Another relevant fact would be peculiar behavior observed in basal attine ants, which in addition to cultivating their fungus, still keeps the fungus growing externally on the surface of the cuticle’s larvae, behavior not seen in the genre Atta. Therefore was verified the alterations in the cuticle of the larvae from Myrmicocrypta, Mycetarotes and Trachymyrmex and this structure is formed by a simple cubic epithelium, whose cells possibly change its shape to prismatic, depending on their secretory activity. The presence of fungi hyphae was observed both on the external side of the basal attine larvae as well as emitting projections to the interior of the cuticle reaching the epithelium and the adipocyte cells. Some authors have suggested that the fungus could benefit the larvae protecting them against occasional pathogens by forming a physical or chemical barrier. Data obtained in this study demonstrated that the fungus deposited on the surface of immature from basal attine maintain a close relationship with them, once the fungus hyphae have the ability to disorganize the lamellar cuticle, penetrating the interior of the cells through the emission of prolongations.
A review of plant phenology in south and central america
(2013-11-01) Morellato, L. Patrícia C. ; Camargo, Maria Gabriela G. ; Gressler, Eliana ; Universidade Estadual Paulista (UNESP)
Phenology has established its status as an integrative environmental science and as a key component for climate change research. We aim to present a review of phenological research in South and Central America. We describe the flowering and fruiting patterns of the main vegetation types studied to date, and highlight areas where phenological information is lacking. Phenological research is still required even though the number of papers published has increased, especially in the twenty-first century. The distribution of phenological studies on South American vegetation was very uneven over the different vegetation types and life forms. Tropical moist forest continues to be, by far, the most widely studied ecosystem while trees were the life-form observed in almost all papers surveyed. Currently, long-term phenological datasets are rare and few long-term monitoring systems are known for South and Central America. Few papers reviewed were concerned with the effects of climatic change and its evaluation using plant phenology, which differed greatly from Northern Hemisphere research which had a strong focus on phenology and climate change. Among new developments we mention phenology and edge effects and fragmentation, and remote monitoring of phenology with digital cameras. Finally, building phenology networks is the greatest challenge for South and Central American phenologists, demanding an effort from and cooperation among universities, research institutions, governmental, and non-governmental agencies.
Anther, ovule and embryological characters in Velloziaceae in relation to the systematics of Pandanales
(2011-01-01) Sajo, Maria das Graças ; Mello-Silva, Renato ; Rudall, Paula J. ; Universidade Estadual Paulista (UNESP) ; Universidade de São Paulo (USP) ; Royal Botanic Gardens
Velloziaceae are a monocot family of five genera and c. 250 species (Mello-Silva, 2009). The family is now assigned to the order Pandanales, a small but morphologically diverse monocot order of five families: Cyclanthaceae, Pandanaceae, Stemonaceae (including Pentastemona Steenis), Triuridaceae and Velloziaceae (APG III, 2009). Within Velloziaceae, three genera occur in South America, of which two are endemic to Brazil (Barbacenia Vand., Vellozia Vand.) and the third is Andean (Barbaceniopsis L.B.Sm.). A fourth genus, Xerophyta Juss., grows in tropical Africa and the fifth, Acanthochlamys P.C.Kao, is endemic to China. In this chapter, we present new data on the anther, ovule and embryology of Velloziaceae in the context of ongoing related studies on floral evolution (e.g. Sajo et al., 2010) and the systematics of Pandanales (Furness and Rudall, 2006; Rudall and Bateman, 2006). Earlier studies on ovule and seed development and androecial features were used to delimit the genera of Velloziaceae (Menezes, 1976, 1980). Embryological features of Pandanales are currently poorly known, though some studies suggest that they are potentially systematically useful. For example, Cheah and Stone (1975) reported an unusual megagametophyte in some Pandanus species, in which nucellar nuclei migrate into the developing embryo sac, and tapetum type is unusually variable within Pandanales (Furness and Rudall, 2006).
Gait velocity, attention and exercise in Parkinson's disease
(2012-07-01) Gobbi, Lilian Teresa Bucken ; Vitorio, Rodrigo ; Teixeira-Arroyo, Claudia ; Lirani-Silva, Ellen ; Rinaldi, Natalia Madalena ; Barbieri, Fabio Augusto ; Pereira, Marcelo Pinto ; Santos, Paulo Cezar Rocha ; Batistela, Rosangela Alice ; Universidade Estadual Paulista (UNESP)
In addition to pharmacological therapy, different modes of interventions has been purposed and applied for people with Parkinson's disease (PD). The results of these interventions have been shown improvements in their quality of life and functional mobility, among others. This study aimed to identify the effects of a 6-month, multimodal exercise program on stride velocity and attentional outcomes in PD patients and to observe the relationship between these dependent variables. Twenty-one patients with idiopathic PD were assessed before and after the multimodal exercise program (three times a week, one hour per session). Outcome measures included the stride velocity of self-paced walking and score (number of right/wrong answers) in the attention test of Wechsler Adult Intelligence Scale (WAIS-III). Gait velocity and the number of errors at WAIS-III improved after the enrollment in the multimodal exercise program. It was observed a significant positive relationship between gait velocity and number of right answers at WAIS-III before the multimodal exercise program. These findings suggest that PD patients with higher attentional levels show less impairment in gait velocity. Although physical exercise was effective to improve motor and cognitive characteristics of PD patients, further study in the form of randomized controlled trial would be required to establish effectiveness of the multimodal exercise program. © 2012 Nova Science Publishers, Inc. All rights reserved.
Technological challenges and advances: From lactic acid to polylactate and copolymers
(2019-01-01) Coelho, Luciana Fontes ; Beitel, Susan Michelz ; Contiero, Jonas ; Universidade Estadual Paulista (UNESP)
Lactic acid is an organic acid that has been extensively used worldwide in a variety of industrial and biotechnological applications. Lactic acid can be obtained chemically or by microbial fermentation. Production by fermentation results in the formation of d(-) or l(+) lactic acid, or racemic mixture, depending on the microorganism used. Pure isomers present specific industrial applications from the polymerization of such monomers; different types of lactic acid polymers (PLA) are formed. The properties of PLA depend on the proportion of enantiomers, which enable the production of polymers with different characteristics directed to specific applications. There are three pathways for producing PLA from lactic acid; direct polymerization and polymerizations by lactide ring opening are the most widely used techniques. The degree of crystallinity and many other important properties, such as strength and melting point, are controlled by the ratio of enantiomers used in the polymers. l(+) lactic acid is used for the synthesis of poly(l-lactic acid) (PLLA), a semicrystalline, biodegradable polymer, with potential application in the packaging industry and in medical products. Poly(d, l-lactic acid), a polymer consisting of two isomers, is degraded more rapidly due to its amorphous structure. PLA has been considered as one of the most promising biodegradable plastics due to it having physical characteristics similar to polymers derived from nonrenewable sources, such as elasticity, stiffness, transparency, thermoresistance, biocompatibility, and good moldability.
Scalable vector graphics and web map publishing
(2007-12-01) Da Silva Ramos, Cristhiane ; Cartwright, W. ; Doin De Almeida, Rosângela ; RMIT University ; Universidade Estadual Paulista (UNESP)
The product development discussed in this chapter aimed at developing a methodology for publishing Brazilian local school atlas on the Web that would be easy-to-use and inexpensive. A low cost solution for publishing atlases on the Web is considered necessary in Brazil because most local school atlases are developed by academic teams with research funds which are, most of the time, very limited. Open Standard Technologies were chosen as the main tool for developing such products because they can be used at no cost. The use of SVG and JavaScript to produce online school atlases proved to be very effective. The final product, tested in Brazil with primary school teachers, received a very positive feedback. The experience described here illustrates that it is possible to develop a digital local atlas for education at greatly reduced costs. It is also possible that, in the future, Brazilian public universities can use their practical knowledge, developed through many years of work with paper atlases, to publish their products directly via the Internet, using the SVG Atlas Templates developed as part of this research. Nevertheless, it is believed that the main outcome of this project will be the 'digital inclusion', not only of public school children, but also of Brazilian children's atlas developers. © 2007 Springer-Verlag Berlin Heidelberg.
Ecotoxicological assays applied in soils contaminated by petroleum hydrocarbons
(2011-12-01) Souza, T. S. ; Chistofoletti, C. A. ; Fontanetti, C. S. ; Universidade Estadual Paulista (UNESP)
Soil is the final destination of several types of residues of anthropic origin, discharged intentionally or accidentally. The environmental impacts resulted from the petroleum industry in the terrestrial ecosystem are a growing problem. Hydrocarbons of low molecular weight, small aliphatics and BTEX (benzene, toluene, ethylbenzene and xylene) present considerable hydrosolubility. BTEX have great mobility in the soil and can reach easily the water table. Polycyclic aromatic hydrocarbons (PAHs) are formed as by-products or incomplete combustion of organic matter. Several PAHs present genotoxic and carcinogenic properties. In the soil, these compounds and the metabolites resulted from their degradation can affect directly the terrestrial biota and indirectly the aquatic ecosystem by percolation; besides presenting potential to affect negatively the human health. Thus, biological assays (bioassays), which consist in the assessment of the exposure effects of live organisms in contaminated soil, have been required. Bioremediation of soils contaminated with petroleum hydrocarbons is an indispensable alternative for the recovery of the quality of the terrestrial ecosystem, through the removal or reduction, complete or partial, of the concentration of these compounds. In this process, microorganisms use the organic compounds present as substrate for the growth and energy generation and convert them into CO2, H2O and biomass. However, it has been documented that the reduction in the concentration of hydrocarbons is not always followed by decrease in the toxicity of the soil; incomplete degradation and the formation of intermediary metabolites may lead to an increase of the toxicity. Due to the complexity of the bioremediation of soils contaminated with petroleum residues, bioassays are indispensable in the evaluation of the success of this process. In this context, it is here presented a review of the principal ecotoxicological assays with microorganisms, plants and invertebrates used in the monitoring of soils contaminated with petroleum hydrocarbons and/or bioremediated. In a complementation to conventional chemical tests, biological assays can be used with success to identify soils contaminated with petroleum residues, assess the efficacy of a bioremediation technology and, finally, monitor sites already restored. © 2011 by Nova Science Publishers, Inc. All rights reserved.
Morphology like a tool to understand the social behavior in ant's larvae
(2012-12-01) Ortiz, Gabriela ; Mathias, Maria Izabel Camargo ; Bueno, Odair Correa ; Universidade Estadual Paulista (UNESP)
All metamorphosing insects pass through four consecutive stages before reaching their adult form and these stages are known as the egg, the larva, the semipupa and the pupa. The larval stage comprising individuals who have completely different morphology of the other three, since the body is devoid of external appendages and with internally adipose tissue. From the larval stage begins the growth of individuals who shed their skins several times and depending on the insect considered the substages vary from 3 to 5. In bees in general there are five larval stages called L1 to L5, interspersed with each other for four periods of change ending in larval and pupal changes when successful-L5 larvae enter the pupal stage, where individuals have had adult characteristics. Since ants have about four larval stages (L1, L2, L3, L4), but this number can vary from 3 to 6 depending on the species. In the larvae of ants there are morphological peculiarities in certain species that set them apart from most reported in the literature so far. An interesting fact was observed in the Argentine ant Linepithema humile, an invasive species, since they present a dorsal protuberance in the sixth abdominal segment found exclusively in their larvae. Researchers have tried to explain the social function of this structure. One function described was the nutrition. However the morphological results obtained in this study suggested that the dorsal protuberance has no secretory function, since ducts or pore channels were not found, only small folds in the cuticle, which does not indicate a secretion release function. The secretion released is just for the cuticle compounds and does not synthesize other one which would be important in social behavior. Therefore the unique social function that can be attributed to the dorsal protuberance was mechanical or serving like a facilitator making it easier for the workers to transport the immatures through the different environments in the colony.Another relevant fact would be peculiar behavior observed in basal attine ants, which in addition to cultivating their fungus, still keeps the fungus growing externally on the surface of the cuticle's larvae, behavior not seen in the genre Atta. Therefore was verified the alterations in the cuticle of the larvae from Myrmicocrypta, Mycetarotes and Trachymyrmex and this structure is formed by a simple cubic epithelium, whose cells possibly change its shape to prismatic, depending on their secretory activity. The presence of fungi hyphae was observed both on the external side of the basal attine larvae as well as emitting projections to the interior of the cuticle reaching the epithelium and the adipocyte cells. Some authors have suggested that the fungus could benefit the larvae protecting them against occasional pathogens by forming a physical or chemical barrier. Data obtained in this study demonstrated that the fungus deposited on the surface of immature from basal attine maintain a close relationship with them, once the fungus hyphae have the ability to disorganize the lamellar cuticle, penetrating the interior of the cells through the emission of prolongations. © 2012 Nova Science Publishers, Inc. All rights reserved.
The effectiveness of artificial neural networks in modelling the nutritional ecology of a blowfly species
(2012-04-01) Watts, Michael J. ; Bianconi, Andre ; Serapiao, Adriane Beatriz S. ; Govone, Jose S. ; Von Zuben, Claudio J. ; The University of Adelaide ; Universidade Estadual Paulista (UNESP)
The larval phase of most blowfly species is considered a critical developmental period in which intense limitation of feeding resources frequently occurs. Furthermore, such a period is characterised by complex ecological processes occurring at both individual and population levels. These processes have been analysed by means of traditional statistical techniques such as simple and multiple linear regression models. Nonetheless, it has been suggested that some important explanatory variables could well introduce non-linearity into the modelling of the nutritional ecology of blowflies. In this context, dynamic aspects of the life history of blowflies could be clarified and detailed by the deployment of machine learning approaches such as artificial neural networks (ANNs), which are mathematical tools widely applied to the resolution of complex problems. A distinguishing feature of neural network models is that their effective implementation is not precluded by the theoretical distribution of the data used. Therefore, the principal aim of this investigation was to use neural network models (namely multi-layer perceptrons and fuzzy neural networks) in order to ascertain whether these tools would be able to outperform a general quadratic model (that is, a second-order regression model with three predictor variables) in predicting pupal weight values (outputs) of experimental populations of Chrysomya megacephala (F.) (Diptera: Calliphoridae), using initial larval density (number of larvae), amount of available food, and pupal size as input variables. These input variables may have generated non-linear variation in the output values, and fuzzy neural networks provided more accurate outcomes than the general quadratic model (i.e. the statistical model). The superiority of fuzzy neural networks over a regression-based statistical method does represent an important fact, because more accurate models may well clarify several intricate aspects regarding the nutritional ecology of blowflies. Additionally, the extraction of fuzzy rules from the fuzzy neural networks provided an easily comprehensible way of describing what the networks had learnt. © 2012 by Nova Science Publishers, Inc. All rights reserved.
Fish assemblage subjected to strong anthropogenic stress: The case of the barra bonita reservoir, tietê river basin, São Paulo, Brazil
(2008-04-01) Petesse, M. L. ; Universidade Estadual Paulista (UNESP)
The Barra Bonita reservoir (S=310 km2; z =10,1 m) is an ecosystem subjected tostrong anthropogenic stress. It is located in the central part of the Tietê river basin - SãoPaulo State, characterized by the widespread urbanization, industrial development andintensive agricultural use of the soil. The Barra Bonita reservoir has high social-economicimportance due to hydropower generation, navigation and fisheries. From a limnologicalpoint of view, it is classified as polymictic and eutrophic. The purpose of this study wasto characterize the actual fish assemblage in the reservoir and, by means of the speciesabundancerelationship, value its organization in relation to the disturbances caused bythe anthropogenic impact. For the fish sampling we chose 24 sites located in threedifferent habitats: reservoir shoreline, mouth of tributary and centre. Samples were takenin two periods of the year: dry season (winter, August-September 2003), and rainy season(summer-February 2004). Fish sampling was standardized by using 10 gillnets with meshsizes ranging from 3 to 12 cm between opposite knots and funnel traps. At each point wealso measured some morphological, physical-chemical and environmental variables.Multivariate analyses (three way-anova and ancova) were employed to, respectively,point out space and temporal variations in the Catch per Unit Effort in weight (CPUEW)and to detect the importance of morphological, physical-chemical and environmentalvariables on Shannon species diversity (H' in number and weight). A total of 35 species,belonging to 14 families and 4 orders, were caught. Fish assemblage is composed ofsmall body-sized species, with wide feed flexibility and high reproductive compensation. The superposition of the biological cycles of the fishes with the hydrologicalmanagement of the reservoir, suggests that only those with multiple spawn and/orparental care have success. The CPUEW distribution shows significant statisticaldifferences between seasons, zones and habitat, indicating the presence of transversalmigration from the centre to the shoreline and mouth of the tributary habitats, especiallyin the rainy season. The variables that influenced the diversity of the fish assemblagewere: depth, transparency and landscape for H'N and H'W; temperature (H'N);conductibility and macrophytes (H'W). The correlation of diversity with the depth wasnegative, showing that the tributary mouths and the shoreline habitats of the reservoir arethe most explored by the ichthyofauna. The environmental variables selected(surrounding landscape and macrophytes beds) act respectively as external feedingsupport and shelter/nursery habitat, revealing the essential importance of the structuralenvironmental complexity for the diversity maintenance in reservoirs. © 2009 Nova Science Publishers, Inc. All rights reserved.

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