A hybrid heuristic for the multi-plant capacitated lot sizing problem with setup carry-over

This paper addresses the capacitated lot sizing problem (CLSP) with a single stage composed of multiple plants, items and periods with setup carry-over among the periods. The CLSP is well studied and many heuristics have been proposed to solve it. Nevertheless, few researches explored the multi-plant capacitated lot sizing problem (MPCLSP), which means that few solution methods were proposed to solve it. Furthermore, to our knowledge, no study of the MPCLSP with setup carry-over was found in the literature. This paper presents a mathematical model and a GRASP (Greedy Randomized Adaptive Search Procedure) with path relinking to the MPCLSP with setup carry-over. This solution method is an extension and adaptation of a previously adopted methodology without the setup carry-over. Computational tests showed that the improvement of the setup carry-over is significant in terms of the solution value with a low increase in computational time.

Recovery of p-TBC from a butadiene washing stream in a pilot plant

Results obtained in a pilot-scale unit designed for COD removal and p-TBC (p-tert-butylcatechol) recovery from a butadiene washing stream (pH 14, 200,000 mg COD L-1, highly toxic) at a petrochemical industry are presented. By adding H3PO4, phase separation is achieved and p-TBC is successfully recovered (88 g L-1 of washing stream). Information (time for phase separation and organic phase characterization) was gathered for designing a future industrial unit. The estimated heat generation rate was 990 kJ min-1 and 15 min were enough to promote phase separation for a liquid column of approximately 1.15 m.

A century of research: what have we learned about the interaction of Trypanosoma cruzi with host cells?

Since the discovery of Trypanosoma cruzi and the brilliant description of the then-referred to "new tripanosomiasis" by Carlos Chagas 100 years ago, a great deal of scientific effort and curiosity has been devoted to understanding how this parasite invades and colonises mammalian host cells. This is a key step in the survival of the parasite within the vertebrate host, and although much has been learned over this century, differences in strains or isolates used by different laboratories may have led to conclusions that are not as universal as originally interpreted. Molecular genotyping of the CL-Brener clone confirmed a genetic heterogeneity in the parasite that had been detected previously by other techniques, including zymodeme or schizodeme (kDNA) analysis. T. cruzi can be grouped into at least two major phylogenetic lineages: T. cruzi I, mostly associated with the sylvatic cycle and T. cruzi II, linked to human disease; however, a third lineage, T. cruziIII, has also been proposed. Hybrid isolates, such as the CL-Brener clone, which was chosen for sequencing the genome of the parasite (Elias et al. 2005, El Sayed et al. 2005a), have also been identified. The parasite must be able to invade cells in the mammalian host, and many studies have implicated the flagellated trypomastigotes as the main actor in this process. Several surface components of parasites and some of the host cell receptors with which they interact have been described. Herein, we have attempted to identify milestones in the history of understanding T. cruzi- host cell interactions. Different infective forms of T. cruzi have displayed unexpected requirements for the parasite to attach to the host cell, enter it, and translocate between the parasitophorous vacuole to its final cytoplasmic destination. It is noteworthy that some of the mechanisms originally proposed to be broad in function turned out not to be universal, and multiple interactions involving different repertoires of molecules seem to act in concert to give rise to a rather complex interplay of signalling cascades involving both parasite and cellular components.

Extraction and concentration of biogenic calcium oxalate from plant leaves

The objective of this study was to extract and concentrate calcium oxalate (CaOx) crystals from plant leaves that form the above mentioned crystals. The chemical and physical studies of CaOx from plant to be performed depend on an adequate amount of the crystals. The plant used in this study was croton (Codiaeum variegatum). The leaves were ground in a heavy duty blender and sieved through a 0.20 mm sieve. The suspension obtained was suspended in distilled water. The crystals were concentrated at the bottom of a test tube. The supernatant must be washed until it is free of plant pigments and other organic substances. Biogenic CaOx crystals have well-defined and sharp peaks, indicating very high crystallinity. Moreover, the CaOx crystals were not damaged during the extraction procedure, as can be seen on the scanning electron microscope images. The porposed method can be considered efficient to extract and concentrate biogenic calcium oxalate.

Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera Hydroelectric Plant, São Paulo, Brazil

Yellow fever (YF) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. In the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. Surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. An ELISA (enzyme-linked immunosorbent assay) was standardized for estimation of the prevalence of IgG antibodies against yellow fever virus in monkey sera (Alouatta caraya) from the reservoir area of Porto Primavera Hydroelectric Plant, in the state of São Paulo, Brazil. A total of 570 monkey sera samples were tested and none was reactive to antibodies against yellow fever virus. The results corroborate the epidemiology of yellow fever in the area. Even though it is considered a transition area, there were no reports to date of epizootics or yellow fever outbreaks in humans. Also, entomological investigations did not detect the presence of vectors of this arbovirus infection. ELISA proved to be fast, sensitive, an adequate assay, and an instrument for active search in the epidemiological surveillance of yellow fever allowing the implementation of prevention actions, even before the occurrence of epizootics.

Establishment of a protocol for obtention of neuronal stem cells lineages from the dog olfactory epithelium

A morphological and cell culture study from nasal mucosa of dogs was performed in order to establish a protocol to obtain a cell population committed to neuronal lineage, as a proposal for the treatment of traumatic and degenerative lesions in these animals, so that in the future these results could be applied to the human species. Twelve mongrel dogs of 60-day aged pregnancy were collected from urban pound dogs in São Paulo. Tissue from cribriform ethmoidal lamina of the fetuses was collected at necropsy under sterile conditions around 1h to 2h postmortem by uterine sections and sections from the fetal regions described above. Isolated cells of this tissue were added in DMEM/F-12 medium under standard conditions of incubation (5% CO², >37ºC). Cell culture based on isolated cells from biopsies of the olfactory epithelium showed rapid growth when cultured for 24 hours, showing phase-bright sphere cells found floating around the fragments, attached on culture flasks. After 20 days, a specific type of cells, predominantly ellipsoids or fusiform cells was characterized in vitro. The indirect immunofluorescence examination showed cells expressing markers of neuronal precursors (GFAP, neurofilament, oligodendrocyte, and III â-tubulin). The cell proliferation index showed Ki67 immunostaining with a trend to label cell groups throughout the apical region, while PCNA immunostaining label predominantly cell groups lying above the basal lamina. The transmission electron microscopy from the olfactory epithelium of dogs revealed cells with electron-dense cytoplasm and preserving the same distribution as those of positive cell staining for PCNA. Metabolic activity was confirmed by presence of euchromatin in the greatest part of cells. All these aspects give subsidies to support the hypothesis about resident progenitor cells among the basal cells of the olfactory epithelium, committed to renewal of these cell populations, especially neurons.

PDIA3, HSPA5 and viementin, proteins identified by 2-DE in the valvular tissue, are the target antigens of peripheral and heart infiltrating T cells from chronic rheumatic heart disease patients

Rheumatic fever (RF) is a post-infectious autoimmune disease due to sequel of group A streptococcus (GAS) pharyngitis. Rheumatic heart disease (RHD), the major manifestation of RF, is characterized by inflammation of heart valves and myocardium. Molecular mimicry between GAS antigens and host proteins has been shown at B and T cell level. However the identification of the autoantigens recognized by B and T cells within the inflammatory microenvironment of heart tissue in patients with RHD is still incompletely elucidated. In the present study, we used two-dimensional gel electrophoresis (2-DE) and mass spectrometry to identify valvular tissue proteins target of T cells from chronic RHD patients. We could identify three proteins recognized by heart infiltrating and peripheral T cells as protein disulfide isomerase ER-60 precursor (PDIA3), 78 kD glucose-regulated protein precursor (HSPA5) and vimentin, with coverage of 45%, 43 and 34%, respectively. These proteins were recognized in a proliferation assay by peripheral and heart infiltrating T cells from RHD patients suggesting that they may be involved in the autoimmune reactions that leads to valve damage. We also observed that several other proteins isolated by 2-DE but not identified by mass spectrometry were also recognized by T cells. The identified cardiac proteins are likely relevant antigens involved in T cell-mediated autoimmune responses in RF/RHD that may contribute to the development of RHD

Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera hydroeletric plant, São Paulo, Brazil

A febre amarela (FA) é doença infecciosa aguda de origem viral transmitida por mosquitos. No ciclo silvestre, o vírus é mantido por meio da infecção de macacos e da transmissão transovariana nos vetores. A vigilância sobre populações de primatas não humanos torna-se necessária para detectar a circulação viral, quando ainda está restrito a epizootias, e para determinar sua presença em regiões indenes ou de transição para a doença. Padronizou-se a técnica ELISA (Enzyme Linked Immunosorbent Assay) para determinar a prevalência de anticorpos da classe IgG contra o vírus da FA em soros de bugios (Alouatta caraya) da região do reservatório da Usina Hidrelétrica de Porto Primavera, SP. Foram testados soros de 570 macacos sendo que nenhuma amostra mostrou-se reativa para a presença de anticorpos contra o vírus da FA. Os resultados são coerentes com a epidemiologia da FA na região. Mesmo sendo área de transição, não se conhece, até o momento, ocorrência de epizootia ou surto de FA em humanos e investigações entomológicas não apontaram a presença de vetores para esta arbovirose. A técnica mostrou-se sensível, rápida e útil à vigilância epidemiológica como instrumento de busca ativa permitindo desencadear ações preventivas, como vacinação, antes mesmo do surgimento de epizootias

Deep plant-derived carbon storage in Amazonian podzols

Equatorial podzols are soils characterized by thick sandy horizons overlying more clayey horizons. Organic matter produced in the topsoil is transferred in depth through the sandy horizons and accumulate at the transition, at a depth varying from 1 to more than 3 m, forming deep horizons rich in organic matter (Bh horizons). Although they cover great surfaces in the equatorial zone, these soils are still poorly known. Studying podzols from Amazonia, we found out that the deep Bh horizons in poorly drained podzol areas have a thickness higher than 1m and store unexpected amounts of carbon. The average for the studied area was 66.7 +/- 5.8 kgCm(-2) for the deep Bh and 86.8 +/- 7.1 kgCm(-2) for the whole profile. Extrapolating to the podzol areas of the whole Amazonian basin has been possible thanks to digital maps, giving an order of magnitude around 13.6 +/- 1.1 PgC, at least 12.3 PgC higher than previous estimates. This assessment should be refined by additional investigations, not only in Amazonia but in all equatorial areas where podzols have been identified. Because of the lack of knowledge on the quality and behaviour of the podzol organic matter, the question of the feedback between the climate and the equatorial podzol carbon cycle is open.

Toll-like receptor 4 (TLR4) expression in human and murine pancreatic beta-cells affects cell viability and insulin homeostasis

Background: Toll-like receptor 4 (TLR4) is widely recognized as an essential element in the triggering of innate immunity, binding pathogen-associated molecules such as Lipopolysaccharide (LPS), and in initiating a cascade of pro-inflammatory events. Evidence for TLR4 expression in non-immune cells, including pancreatic beta-cells, has been shown, but, the functional role of TLR4 in the physiology of human pancreatic beta-cells is still to be clearly established. We investigated whether TLR4 is present in beta-cells purified from freshly isolated human islets and confirmed the results using MIN6 mouse insulinoma cells, by analyzing the effects of TLR4 expression on cell viability and insulin homeostasis. Results: CD11b positive macrophages were practically absent from isolated human islets obtained from nondiabetic brain-dead donors, and TLR4 mRNA and cell surface expression were restricted to beta-cells. A significant loss of cell viability was observed in these beta-cells indicating a possible relationship with TLR4 expression. Monitoring gene expression in beta-cells exposed for 48h to the prototypical TLR4 ligand LPS showed a concentration-dependent increase in TLR4 and CD14 transcripts and decreased insulin content and secretion. TLR4-positive MIN6 cells were also LPS-responsive, increasing TLR4 and CD14 mRNA levels and decreasing cell viability and insulin content. Conclusions: Taken together, our data indicate a novel function for TLR4 as a molecule capable of altering homeostasis of pancreatic beta-cells.

Fermentation of Groundnut Shell Enzymatic Hydrolysate for Fuel Ethanol Production by Free and Sorghum Stalks Immobilized Cells of Pichia stipitis NCIM 3498

Groundnut shell (GS), after separation of pod, is readily available as a potential feedstock for production of fermentable sugars. The substrate was delignified with sodium sulfite. The delignified substrate released 670 mg/g of sugars after enzymatic hydrolysis (50 degrees C, 120 rpm, 50 hrs) using commercial cellulases (Dyadic Xylanase PLUS, Dyadic Inc. USA). The groundnut shell enzymatic hydrolysate (45.6 g/L reducing sugars) was fermented for ethanol production with free and sorghum stalks immobilized cells of Pichia stipitis NCIM 3498 under submerged cultivation conditions. Immobilization of yeast cells on sorghum stalks were confirmed by scanning electron microscopy (SEM). A maximum of ethanol production (17.83 g/L, yield 0.44 g/g and 20.45 g/L, yield 0.47 g/g) was observed with free and immobilized cells of P. stipitis respectively in batch fermentation conditions. Recycling of immobilized cells showed a stable ethanol production (20.45 g/L, yield 0.47 g/g) up to 5 batches followed by a gradual downfall in subsequent cycles.

Convergence of developmental mutants into a single tomato model system: 'Micro-Tom' as an effective toolkit for plant development research

Background: The tomato (Solanum lycopersicum L.) plant is both an economically important food crop and an ideal dicot model to investigate various physiological phenomena not possible in Arabidopsis thaliana. Due to the great diversity of tomato cultivars used by the research community, it is often difficult to reliably compare phenotypes. The lack of tomato developmental mutants in a single genetic background prevents the stacking of mutations to facilitate analysis of double and multiple mutants, often required for elucidating developmental pathways. Results: We took advantage of the small size and rapid life cycle of the tomato cultivar Micro-Tom (MT) to create near-isogenic lines (NILs) by introgressing a suite of hormonal and photomorphogenetic mutations (altered sensitivity or endogenous levels of auxin, ethylene, abscisic acid, gibberellin, brassinosteroid, and light response) into this genetic background. To demonstrate the usefulness of this collection, we compared developmental traits between the produced NILs. All expected mutant phenotypes were expressed in the NILs. We also created NILs harboring the wild type alleles for dwarf, self-pruning and uniform fruit, which are mutations characteristic of MT. This amplified both the applications of the mutant collection presented here and of MT as a genetic model system. Conclusions: The community resource presented here is a useful toolkit for plant research, particularly for future studies in plant development, which will require the simultaneous observation of the effect of various hormones, signaling pathways and crosstalk.

Gene expression profile of the plant pathogen Fusarium graminearum under the antagonistic effect of Pantoea agglomerans

The pathogenic fungus Fusarium graminearum is an ongoing threat to agriculture, causing losses in grain yield and quality in diverse crops. Substantial progress has been made in the identification of genes involved in the suppression of phytopathogens by antagonistic microorganisms; however, limited information regarding responses of plant pathogens to these biocontrol agents is available. Gene expression analysis was used to identify differentially expressed transcripts of the fungal plant pathogen F. graminearum under antagonistic effect of the bacterium Pantoea agglomerans. A macroarray was constructed, using 1014 transcripts from an F. graminearum cDNA library. Probes consisted of the cDNA of F. graminearum grown in the presence and in the absence of P. agglomerans. Twenty-nine genes were either up (19) or down (10) regulated during interaction with the antagonist bacterium. Genes encoding proteins associated with fungal defense and/or virulence or with nutritional and oxidative stress responses were induced. The repressed genes coded for a zinc finger protein associated with cell division, proteins containing cellular signaling domains, respiratory chain proteins, and chaperone-type proteins. These data give molecular and biochemical evidence of response of F. graminearum to an antagonist and could help develop effective biocontrol procedures for pathogenic plant fungi.

CHARACTERIZATION OF MICROSATELLITE LOCI IN HIMATANTHUS DRASTICUS (APOCYNACEAE), A MEDICINAL PLANT FROM THE BRAZILIAN SAVANNA

Premise of the study: We developed a new set of microsatellite markers for studying the genome of the janaguba tree, Himatanthus drasticus (Mart.) Plumel, which is used in folk medicine in northeastern Brazil. These novel markers are being used to evaluate the effect of harvesting on the genetic structure and diversity of natural populations of this species. Methods and Results: Microsatellite loci were isolated from an enriched H. drasticus genomic library. Nine primer pairs successfully amplified polymorphic microsatellite regions, with an average of 8.5 alleles per locus. The average values of observed and expected heterozygosity were 0.456 and 0.601, respectively. Conclusions: The microsatellite markers described here are valuable tools for population genetics studies of H. drasticus. The majority of the primers also amplified sequences in the genome of another species of the same genus. This new set of markers may be useful in designing a genetic conservation strategy and a sustainable management plan for the species.