Functional morphology of the gastric mills of carnivorous, omnivorous, and herbivorous land crabs

Terrestrial decapods consume a wide variety of plant and animal material. The potential adaptations of carnivorous, omnivorous, and herbivorous terrestrial crustaceans were studied by examining the functional morphology of the gastric mill. Two closely related species from each feeding preference group were examined to identify which features of the mill were due to phylogeny and which were due to adaptation. The morphology of the gastric mill matched the diet well; the gastric mills of the carnivorous species (Geograpsus grayi and Geograpsus crinipes) possessed a blunt, rounded medial tooth and flattened lateral teeth with a longitudinal grinding groove. These features make them well suited to a carnivorous diet of soft animal tissue as well as hard material, such as arthropod exoskeleton. In contrast, the mill of the herbivorous gecarcinids (Gecarcoidea natalis and Discoplax hirtipes) consisted of a medial tooth with sharp transverse ridges and lateral teeth with sharp interlocking cusps and ridges and no grinding surface. These features would efficiently shred fibrous plant material. The morphology of the mill of the omnivorous coenobitids (Coenobita perlatus and Birgus latro) was more generalized toward a mixed diet. However, the mill of B. latro was more adapted to deal with highly nutritious food items, such as nuts and heavily calcified decapods. Its mill possessed lateral teeth with extended ridges, which sat close to the calcified cardiopyloric valve to form a flattened floor. Hard items trapped in the mill would be crushed against this surface by the medial tooth.

Improving the prediction of the roll separating force in a hot steel finishing mill

This paper focuses on the development of a hybrid phenomenological/inductive model to improve the current physical setup force model on a five stand industrial hot strip finishing mill. We approached the problem from two directions. In the first approach, the starting point was the output of the current setup force model. A feedforward multilayer perceptron (MLP) model was then used to estimate the true roll separating force using some other available variables as additional inputs to the model.

It was found that it is possible to significantly improve the estimation of a roll separating force from 5.3% error on average with the current setup model to 2.5% error on average with the hybrid model. The corresponding improvements for the first coils are from 7.5% with the current model to 3.8% with the hybrid model. This was achieved by inclusion, in addition to each stand's force from the current model, the contributions from setup forces from the other stands, as well as the contributions from a limited set of additional variables such as: a) aim width; b) setup thickness; c) setup temperature; and d) measured force from the previous coil.

In the second approach, we investigated the correlation between the large errors in the current model and input parameters of the model. The data set was split into two subsets, one representing the "normal" level of error between the current model and the measured force value, while the other set contained the coils with a "large" level of error. Additional set of data with changes in each coil's inputs from the previous coil's inputs was created to investigate the dependency on the previous coil.

The data sets were then analyzed using a C4.5 decision tree. The main findings were that the level of the speed vernier variable is highly correlated with the large errors in the current setup model. Specifically, a high positive speed vernier value often correlated to a large error. Secondly, it has been found that large changes to the model flow stress values between coils are correlated frequently with larger errors in the current setup force model.

A natureza teleológica do princípio darwiniano de seleção natural : a articulação do metafísico e do epistemológico na origem das espécies

A presente tese tem por objetivo o exame da natureza explicativa do princípio de seleção natural (PSN) na Origem das Espécies de Charles Darwin, enquanto tal princípio exibe uma natureza teleológica, como ponto de articulação entre suas dimensões metafísica e epistemológica. A motivação inicial para este estudo encontrou-se num interesse mais profundo pela questão da "racionalidade", através do exame das relações entre ciência e nÃo-ciência provocada pelo reacender-se das discussões sobre evolucionismo versus criacionismo, nas escolas norte-americanas na década de 80. Todavia, uma detida leitura da Origem e o rastreamento de seu questionamento na trajetória intelectual de Darwin buscando empreender uma análise cuidadosa da teoria darwiniana como exigência prévia àquele exame mostrou-se, por si só, filosoficamente tão rica e absorvente, que direcionou a essa análise todos os esforços da presente tese. De imediato, o caráter multifacético dos padrões explicativos e das estratégias argumentativas encontradas na elaboração e defesa da teoria apresentada por Darwin na Origem das Espécies indicava a relevância de uma análise de PSN para a história e filosofia da ciência. De sua leitura igualmente aflorava uma nova abordagem para a questão teleológica, tema instigante nos questionamentos contemporâneos. O exame então empreendido teve, entre seus pressupostos orientadores, quatro pontos-chave: (1) a percepção do mútuo remetimento da História e da Filosofia da Ciência para a elucidaçÃo da natureza da produçÃo científica, partilhando certas idéias básicas das análises feitas por Thomas Kuhn, Paul Feyerabend e Imre Lakatos, entre outros, e, sobretudo, seu reconhecimento do papel do núcleo metafísico presente no questionamento científico; (2) a busca de uma compreensão contextualizadora da estrutura lógico-conceitual em que se insere a função e sentido do princípio a ser investigado, (a) privilegiando o contexto "interno" da obra e do desenvolvimento do pensamento de Darwin, mas buscando o contraponto esclarecedor em seu contexto "externo" e (b) construindo um referencial de análise emergente da estrutura contextual; (3) a visualização de uma relação todo-parte de mútuo suporte na estruturação da integridade contextual, constituindo uma tessitura tipo rede, em que a clarificação das partes, considerada sua posição no todo, faz avançar a inteligibilidade desse e confere-lhe sustentação, a qual, em troca, reverte em clarificação e fortalecimento das partes; (4) a busca de um novo enfoque da teleologia, numa nova perspectiva das relações explicativas e causais, pelo exame das bases metafísicas e epistemológicas da questão à época de Darwin e de tematizações e ambigüidades que permeiam o seu tratamento contemporaneamente. À luz de tais pressupostos, o fio condutor de trabalho é a análise da Origem das Espécies, em sua 6ª. ediçÃo inglesa (a última revisada pelo próprio Darwin), buscando complementar as requeridas elucidações, sobretudo no que concerne a certos pressupostos do pensamento de Darwin, nas obras e textos que perfazem sua trajetória intelectual (diário da viagem a bordo do Beagle, Notebooks 1836-1844, Ensaios de 1842 e 1844, o longo manuscrito de 1856-1858, correspondência) até a exposição madura de seu pensamento na Origem. Assim procedendo, o exame da natureza explicativa de PSN parte (I Parte) de uma leitura da Origem das Espécies como uma história da Natureza, constituindo o contexto no qual cabe dimensionar a função e sentido de PSN como a parte privilegiada da argumentação/narrativa da Origem como um todo (capítulo 1). Desse modo, a clarificação de PSN, encerrando a idéia mestra de que as espécies na Natureza originamse umas de outras por seleção natural, demanda a inteligibilidade e integração provida por esse princípio ao contexto da obra, ao "um longo argumento" em sua integridade, e essa inteligibilidade reverte em clarificação do próprio princípio. Nesse sentido, a atenção à estrutura argumentativa/narrativa da Origem permite ver como as partes desse argumento/os capítulos da narrativa estruturam-se, fugindo às rotulações usuais de um modelo "indutivo" ou "dedutivo", e constituindo, antes, uma rede argumentativa, em que os avanços, a seqüência dos capítulos, leva a retomadas, a uma nova inteligibilidade das etapas/capítulos anteriores, fortalecendo, na integridade desse movimento, as bases para novos avanços e crescentes explicitações e fortalecimento de sua sustentaçÃo. A atençÃo a esse movimento argumentativo leva igualmente a uma análise conceitual de "PSN" e "Natureza", ao longo da obra. Para tanto, procede-se a uma cuidadosa análise lógicosemântica da ocorrência desses conceitos no texto (capítulos 2 e 3, respectivamente), encontrando na visão de Natureza como "luta pela existência" um ponto privilegiado para a exploração de sua articulação. A análise realizada na primeira parte revela a natureza epistemológica e metafísica de PSN em sua condição explicativa e permite colocar a peculiar relação que se estabelece entre PSN (parte) e Natureza (todo) em termos de uma visão teleológica. No entanto, um aprofundamento desse ponto pede, antes (II parte), um exame mais detido dos conceitos de "explicação" e de "causa" na perspectiva darwiniana. Buscando uma compreensão contextualizadora, o contraponto "externo" ao contexto da Origem é balizado pelo enfoque dos padrões de cientificidade encontrados nas filosofias da ciência de John Herschel, William Whewell e Stuart Mill (capítulo 4). A construção de um referencial "interno", ponto a ser enfatizado, parte da análise lógico-conceitual do uso de "explicaçÃo", "causa" e cognatos feito no texto, levando, através de sucessivos refinamentos de análise, a uma ampliação e aprofundamento do elenco inicial de significações, de modo a determinar compreensivos focos orientadores de análise e identificar dimensões fundamentais do esforço explicativo darwiniano (capítulos 5, 6, 7, 8, 9). A exploraçÃo epistemológica conduzida na segunda parte fornece o instrumento analítico que permite retomar a colocação inicial da função e sentido de PSN em suas relações com o conceito de Natureza, projetando a indagação epistemológica no âmbito da especulação metafísica. Essa dupla dimensão de PSN pode então ser focalizada, tratando-se agora da articulação do epistemológico e do metafísico, presente na natureza explicativa de PSN - e o fazendo enquanto PSN exibe uma natureza teleológica (III Parte). Cabe, inicialmente, estabelecer, face ao exame realizado na segunda parte, os alcances e limites dos níveis e padrões explicativos e das estratégias argumentativas darwinianas, mostrando sua "novidade" e seu caráter multifacético (capítulo 10), a fim de compreender o escopo explicativo de PSN. Esse escopo, por sua vez, cabe vê-lo concretizado em sua função explicativa, através da reconstrução de argumentos-chave da Origem e representativos de seus diferentes níveis explicativos (capítulo 11). Assim visto, o poder explicativo de PSN pode ser compreendido como sendo estabelecido em duas grandes e mutuamente remissivas etapas: em sua fundamentação, como um princípio da Natureza, e em sua justificação, pelo seu poder explicativo operando em diferentes níveis e assim viabilizando empiricamente a visão de Natureza que lhe serve de fundamento (capítulo 12). Desse modo, a dimensão epistemológica de PSN, tornando o que ocorre na Natureza inteligível como objeto de conhecimento, operacionaliza a dimensão metafísica, ou seja, a visão do próprio "ser" da Natureza que lhe serve de fundamento - PSN é a Natureza no exercício de seu poder, é a Natureza (concebida como sistema que recebe suas cores em termos de "luta pela existência") atualizada. Em ambas dimensões explicativas, PSN exibe uma natureza teleológica, enquanto dá lugar a explicações telelógicas e apresenta-se como princípio teleologicamente fundado, abrindo o caminho a um novo enfoque da questão teleológica, redimensionando o tratamento de muitas das ambiguidades encontradas na problematização contemporânea dessa questão.

The sugar cane vegetal residues unloaded in the sugar mill: Operational costs and physical characteristics

Brazil produced in 2002/03 season 317.87×106tons of sugar cane stalks and 36.88×106tons of vegetal residues (green leaves, dry leaves and tops) in a planted area of 4.61×106 hectares (ha). These residues have a useful heat of 3,613.14Mcal.t-1. Currently most of this biomass is burned as a pre-harvest practice. The doubt persists in the system type that it must be adopted to pick up, load, transport and unload this biomass at the sugar mill boilers. This study analyzed 22 variables related to operational costs and physical characteristics of these residues in a field situation using a JOHN DEERE® 6850 forage harvester with two different treatments: T1 and T2 (two types of rakes) with 6 repetitions each one. The geographic location of the studied area that belongs to COSTA PINTO MILL (COSAN® Group) is: Latitude 22°40'30S and Longitude 47°36'38W. The adopted methodology was proposed by Ripoli et al. (2002). The obtained results at a 5% level of significance showed that both treatments did not differed significantly between them. Some of the results were, where EBP stands for Oil Equivalent Barrel: Windrowing (T1=US$0.17.EBP-1 and US$9.59.ha-1, T2=US$0.08.EBP-1 and US$4.27.ha-1); Pick up (T1=US$1.31.EBP-1 and US$44.29.ha-1, T2 =US$1.37.EBP-1 and US$48.36.ha-1); Transportation (T1=US$1.27.EBP-1 and US$14,30.ha -1, T2=US$1.33.EBP-1 and US$14,80.ha -1), Unloading at the sugar mill (T1=US$0.30.EBP-1 and US$3.39.ha-1, T2=US$0.32.EBP-1 and US$3.51.ha-1); Total (T1=US$3.05.EBP-1 and US$71.57.ha-1, T2=US$3.10.EBP-1 and US$70.94.ha-1). Confronting the obtained data with the ones in the bibliography, this system revealed itself more expensive than the baling system or the integral harvest system using combines.

Effect of ricinoleic acid esters from castor oil (Ricinus communis) on the oocyte yolk components of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Rhipicephalus sanguineus are bloodsucking ectoparasites, whose main host is the domestic dog, thus being present in urban areas and closely located to people. Eventually, this tick species parasitize humans and can become a potential vector of infectious diseases. Methods to control this type of pest have been the focus of many research groups worldwide. The use of natural products is increasingly considered nowadays, due to the low toxicity levels to the host and low waste generation to the environment. This study tested the effect of ricinoleic acid esters from castor oil (as an potential acaricide) on the reproductive system of R sanguineus females, more specifically on the vitellogenesis process. For this, two groups were established: the control group (CG) and the treatment group (TG) with five rabbits in each (New Zealand White), used as hosts. NaCl and ester were added to rabbits' food and offered to the hosts. After full engorgement, the females were collected and had their ovaries extracted. The ticks ovaries were submitted to histochemical techniques so the effects of esters could be observed over polysaccharides, proteins and lipids yolk. Changes in the deposition of yolk components were observed. This caused modifications on elements of polysaccharide origin and on glycoprotein compounds, interfering in the final yolk synthesis and compromising the development of the future embryo. © 2012.

Neurotoxic action of permethrin in Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) female ticks. Morphological and cytochemical evaluation of the central nervous system

Studies on the molecular bases of the neurotoxic action of acaricides are found in the literature; but there are no studies of this action on the nervous system of ticks at the cellular level. The present study describes the morphological and cytochemical changes in the synganglion of Rhipicephalus sanguineus semi-engorged females exposed to different concentrations of permethrin, a pyrethroid with recognized neurotoxic action. Permethrin induced the degeneration of the synganglion through a process of apoptosis involving autophagy, characterized by the condensation and margination of the chromatin, formation of blebs in the nuclear envelope and fragmentation of the nucleus, loss of shape of neural cells and integrity of cellular membrane, cytoplasmic shrinkage, and lower levels of acid phosphatase in the nervous tissue as the concentration of permethrin increased. This study provided further evidence of the neurotoxic action of permethrin, which impairs the metabolism of R. sanguineus nervous systems, and consequently the physiology of other systems, dependent on the neural control. These results provide cytochemical and histological confirmation of the neurotoxic action of permethrin, previously inferred from molecular and tick behavioral evidence. © 2013 Elsevier B.V.

John Gledson reescreve Milton Hatoum: a teoria e a experiência da tradução cultural

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bioremediation of PAHs - Limitations and soultions

Introduction 1.1 Occurrence of polycyclic aromatic hydrocarbons (PAH) in the environment Worldwide industrial and agricultural developments have released a large number of natural and synthetic hazardous compounds into the environment due to careless waste disposal, illegal waste dumping and accidental spills. As a result, there are numerous sites in the world that require cleanup of soils and groundwater. Polycyclic aromatic hydrocarbons (PAHs) are one of the major groups of these contaminants (Da Silva et al., 2003). PAHs constitute a diverse class of organic compounds consisting of two or more aromatic rings with various structural configurations (Prabhu and Phale, 2003). Being a derivative of benzene, PAHs are thermodynamically stable. In addition, these chemicals tend to adhere to particle surfaces, such as soils, because of their low water solubility and strong hydrophobicity, and this results in greater persistence under natural conditions. This persistence coupled with their potential carcinogenicity makes PAHs problematic environmental contaminants (Cerniglia, 1992; Sutherland, 1992). PAHs are widely found in high concentrations at many industrial sites, particularly those associated with petroleum, gas production and wood preserving industries (Wilson and Jones, 1993). 1.2 Remediation technologies Conventional techniques used for the remediation of soil polluted with organic contaminants include excavation of the contaminated soil and disposal to a landfill or capping - containment - of the contaminated areas of a site. These methods have some drawbacks. The first method simply moves the contamination elsewhere and may create significant risks in the excavation, handling and transport of hazardous material. Additionally, it is very difficult and increasingly expensive to find new landfill sites for the final disposal of the material. The cap and containment method is only an interim solution since the contamination remains on site, requiring monitoring and maintenance of the isolation barriers long into the future, with all the associated costs and potential liability. A better approach than these traditional methods is to completely destroy the pollutants, if possible, or transform them into harmless substances. Some technologies that have been used are high-temperature incineration and various types of chemical decomposition (for example, base-catalyzed dechlorination, UV oxidation). However, these methods have significant disadvantages, principally their technological complexity, high cost , and the lack of public acceptance. Bioremediation, on the contrast, is a promising option for the complete removal and destruction of contaminants. 1.3 Bioremediation of PAH contaminated soil & groundwater Bioremediation is the use of living organisms, primarily microorganisms, to degrade or detoxify hazardous wastes into harmless substances such as carbon dioxide, water and cell biomass Most PAHs are biodegradable unter natural conditions (Da Silva et al., 2003; Meysami and Baheri, 2003) and bioremediation for cleanup of PAH wastes has been extensively studied at both laboratory and commercial levels- It has been implemented at a number of contaminated sites, including the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, the Mega Borg spill off the Texas coast in 1990 and the Burgan Oil Field, Kuwait in 1994 (Purwaningsih, 2002). Different strategies for PAH bioremediation, such as in situ , ex situ or on site bioremediation were developed in recent years. In situ bioremediation is a technique that is applied to soil and groundwater at the site without removing the contaminated soil or groundwater, based on the provision of optimum conditions for microbiological contaminant breakdown.. Ex situ bioremediation of PAHs, on the other hand, is a technique applied to soil and groundwater which has been removed from the site via excavation (soil) or pumping (water). Hazardous contaminants are converted in controlled bioreactors into harmless compounds in an efficient manner. 1.4 Bioavailability of PAH in the subsurface Frequently, PAH contamination in the environment is occurs as contaminants that are sorbed onto soilparticles rather than in phase (NAPL, non aqueous phase liquids). It is known that the biodegradation rate of most PAHs sorbed onto soil is far lower than rates measured in solution cultures of microorganisms with pure solid pollutants (Alexander and Scow, 1989; Hamaker, 1972). It is generally believed that only that fraction of PAHs dissolved in the solution can be metabolized by microorganisms in soil. The amount of contaminant that can be readily taken up and degraded by microorganisms is defined as bioavailability (Bosma et al., 1997; Maier, 2000). Two phenomena have been suggested to cause the low bioavailability of PAHs in soil (Danielsson, 2000). The first one is strong adsorption of the contaminants to the soil constituents which then leads to very slow release rates of contaminants to the aqueous phase. Sorption is often well correlated with soil organic matter content (Means, 1980) and significantly reduces biodegradation (Manilal and Alexander, 1991). The second phenomenon is slow mass transfer of pollutants, such as pore diffusion in the soil aggregates or diffusion in the organic matter in the soil. The complex set of these physical, chemical and biological processes is schematically illustrated in Figure 1. As shown in Figure 1, biodegradation processes are taking place in the soil solution while diffusion processes occur in the narrow pores in and between soil aggregates (Danielsson, 2000). Seemingly contradictory studies can be found in the literature that indicate the rate and final extent of metabolism may be either lower or higher for sorbed PAHs by soil than those for pure PAHs (Van Loosdrecht et al., 1990). These contrasting results demonstrate that the bioavailability of organic contaminants sorbed onto soil is far from being well understood. Besides bioavailability, there are several other factors influencing the rate and extent of biodegradation of PAHs in soil including microbial population characteristics, physical and chemical properties of PAHs and environmental factors (temperature, moisture, pH, degree of contamination). Figure 1: Schematic diagram showing possible rate-limiting processes during bioremediation of hydrophobic organic contaminants in a contaminated soil-water system (not to scale) (Danielsson, 2000). 1.5 Increasing the bioavailability of PAH in soil Attempts to improve the biodegradation of PAHs in soil by increasing their bioavailability include the use of surfactants , solvents or solubility enhancers.. However, introduction of synthetic surfactant may result in the addition of one more pollutant. (Wang and Brusseau, 1993).A study conducted by Mulder et al. showed that the introduction of hydropropyl-ß-cyclodextrin (HPCD), a well-known PAH solubility enhancer, significantly increased the solubilization of PAHs although it did not improve the biodegradation rate of PAHs (Mulder et al., 1998), indicating that further research is required in order to develop a feasible and efficient remediation method. Enhancing the extent of PAHs mass transfer from the soil phase to the liquid might prove an efficient and environmentally low-risk alternative way of addressing the problem of slow PAH biodegradation in soil.

Letter from John Lathrop to Eliphalet Pearson, 1805 October 30

One folded-leaf containing a letter from John Lathrop to Pearson requesting his attendance at a meeting of the Harvard Corporation.

A flora of North America :containing abridged descriptions of all the known indigenous and naturalized plants growing north of Mexico, arranged according to the natural system /by John Torrey and Asa Gray.

v.2 (1841-1843)

Letter from Daniel Upton to James Savage, 1799 September 29

Daniel Upton wrote this letter from Machias, Maine on September 29, 1799; it is addressed to James Savage, who was then a freshman at Harvard College. In the letter, Upton advises Savage to study ardently, avoiding the temptation to procrastinate. He thanks Savage for having sent him a copy of "Mr. Lowell's oration" and sends greetings to a Mr. Holbrook and Mr. Jones. He also passes along the fond wishes of those in Machias who know Savage, including John Cooper and his wife, Phineas Bruce and his wife, and Hannah Bruce (Upton's future wife). Upton explains that he is writing the letter in a hurry because he is sending it on board with Captain Merryman, who is about to set sail, presumably for Boston.