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AbstractHIV-1 infection is a global epidemic whose treatment is limited majorly by viral resistance and adverse effects. Natural products from algae have been studied for many years, including antiviral, being an alternative to anti-HIV drug design. Since the isolation of natural products can be a hurdle, molecular modeling is an important tool to study these compounds. Herein, structure-activity relationship, molecular docking, and molecular dynamic studies were performed to direct the studies of ten marine natural products with anti-HIV activity. In the structure-activity relationship, descriptors were identified associating the anti-HIV activity of five diterpenes with possible action on the reverse transcriptase allosteric site. These diterpenes were evaluated by molecular docking, and it was identified that only dolabelladienetriol interacted in the allosteric site. Molecular dynamics suggested that the dolabelladienetriol might interfere with the viral RNA binding to HIV-1 RT by inducing a conformational change of the enzyme. Also, in silicoADMET simulations predicts that the dolabelladienetriol present a high potential to be successfully developed as a drug. Thus, applying in silicoapproaches was possible to suggest potential anti-HIV compounds derived from marine natural products.Communicated by Ramaswamy H. Sarma

Among other numerical issues, it is well known that the finite element method (FEM) lacks objectivity in reproducing high deformation rates due to extreme external actions. In geotechnical applications, the coupling of large solid deformations with the pore fluid flow is a critical subject, being one of the multiple scenarios where FEM could have restricted applications. In order to overcome the aforementioned numerical drawbacks, the generic theoretical approach presented in this work is implemented in the context of an explicit numerical method known as the material point method (MPM). Since the MPM can be viewed as a special Lagrangian FEM with particle quadrature and continuous mesh updating, the improved formulation and numerical implementation presented here are well suited for the study of coupled water pore pressure and soil deformation models. One important aspect of the presented coupled formulation is the assumption of two independent sets of Lagrangian material points for each phase. This characteristic leads to a numerical tool oriented to large deformations simulations in saturated porous media, with a fully coupled thermodynamically consistent formulation. To illustrate its robustness and accuracy, the approach is applied to two different real engineering applications: progressive failure modeling of a granular slope and river levees. The obtained results show that the physics of fluid flow through porous media is adequately represented in each analyzed case. It is also proved that it accurately represents the kinematics of soil skeleton and water phase for fully saturated cases, ensuring mass conservation of all constituents.

This work demonstrated the catalytic performance of Cercospora kikichiilipase immobilized onto chitosan acetate microparticles activated with different cross-linking agents and dried using a fluidized-bed system. The activating agent affected the lipase activity, and the highest immobilizing yield was achieved by the chitosan microparticles activated with 1.5% glutaraldehyde (93.7%) followed by activation with metaperiodate (78.9%) and epichlorohydrin (70.6%). The immobilized biocatalysts produced showed low moisture content and water activity, namely, 3.5% and 0.12, respectively; and high stability under storage conditions maintaining 77.7% of its initial activity after 6 months at 5 °C. The industrial applicability of the biocatalyst was assessed in the transesterification of coconut oil (Cocos nuciferaoil) using ethanol as an acylant agent. The viscosity value for the coconut oil (29 mm2·s–1) sharply decreased to 3.2 mm2·s–1, upon the progress of transesterification reaction. This represents a final product containing high ester content (97.9%) and low levels of acylglycerides (0.7%). The stability of chitosan-immobilized lipase was also estimated, under successive batch runs, and after five reuse cycles the ester content remained above 96.5%. Therefore, the immobilization process developed and the immobilized derivative produced could represent an alternative route both for protein engineering (specially for enzyme stability) as for biodiesel production employing lipases.

This study evaluates the influence of landscape on the feeding habits of the European badger (Meles meles) in the southern Iberian Peninsula and discusses some potential implications that the scenarios of climate change and land use and land cover changes proposed for this region could have on the diet of badgers. We particularly explore whether different vegetation types and land uses affect its feeding habits across three arid landscapes: maquia, xeric shrubland, and forestry. Although badger diet in Mediterranean environments has been described as frugivorous, in which the key food resources are wild or cultivated fruit (e.g., olives or figs), this species’ diet may vary in response to landscape composition, with individuals locally consuming different key items in an arid Mediterranean context. Based on the analysis of 252 scats collected monthly from June 2011 to May 2012, we found that diet significantly varied among the landscapes studied: Insects, carob, and small mammals were the key items in the maquia, figs, and oranges in the xeric shrubland, and earthworms and insects in the forestry. This shows that in an arid context, badgers adapt their diet to particular landscape conditions. Thus, our results support the important role of human activities, specifically the fruit orchards, in shaping badger diet and highlight the contrasting dietary differences of badgers, i.e., from an animal-based diet to one dominated by cultivated fruits when this type of crops are relevant in the landscape. In these circumstances and based on the proven effect of precipitation and land management practices on the food items identified here, we suggest that crop abandonment and less precipitation could reduce the availability of the badger’s key food resources, locally affecting its fitness and including local extinction where the habitats are extremely arid or crop abandonment is dominant.

In this work was produced an immobilized biocatalyst from Cercospora kikuchiilipase with beneficial catalytic activity and stability. The immobilized derivative was used in the ethanolysis of coconut oil. This is a great option for the Brazilian renewable fuel production, because both coconut oil and ethanol are promptly available in the country, at a reasonably low cost. For this, lipase was immobilized on rice husk (5.5 mgproteing–1support) by covalent binding using spouted bed drying (gas flow rate, 0.66 m3min–1; temperature, 100 °C; and solution flow rate, 5.5 g min–1). In a typical batch run, the immobilized derivative was added at a vegetable oil/ethanol molar ratio of 1:12 using tert-butanol as the solvent. The feasibility of immobilization and drying processes was demonstrated toward biodiesel production, attaining a high ester content (97.1%) and low levels of acylglycerides (0.9%) after 72 h. Further properties, such as viscosity (4.56 mm cm−2) and density (888 kg m−3), are in agreement with specifications required by the ASTM D6751 to be used as alternative biofuel.

O advento da cirurgia minimamente invasiva, desde a década de 90 levou diversos centros internacionais de cirurgia urológica a desenvolver a retroperitoneoscopia como via de acesso para o tratamento cirúrgico de múltiplas patologias urológicas. Objetivos:O objetivo deste trabalho foi analisar a experiência inicial em Retroperitoneoscopia do Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa.

AbstractThis paper integrates a methodology for an assessment previous to organic certification of transition farms. The methodology was designed and applied to a farm in the municipality of Villaflores, Chiapas. Research consisted of grouping certification standards from different certification agencies into an integrated methodology for evaluating the farm prior to it being submitted to the certification process. The norms proposed by the International Federation of Organic Agriculture Movements and the Mexican certifier of ecological products were utilized—both of these accredited by the German certification program—as well as the Japanese Ministry of Agriculture’s principles of organic agriculture. The methodology was based on a systemic approach and applied using agricultural anthropology. Field research was conducted from January-May 2012, through interviews, field observations and triangulation of information. Results indicated that within the agricultural sub-system of the farm, 77% of indicators meet the norms of organic certification and within the animal subsystem only 74%. This study permits the pre-assessment of farms and the progress quantification toward organic certification. Given the cost of taking on the certification process, this pre-assessment represents an important tool to help small farmers develop their capacity to identify farm components and interactions, keep records on all farm activities and plan organic transitions.

AbstractThe perceptions on sustainable livestock training given to farmers from different communities of the Biosphere Reserve La Sepultura (BIRESE) were analyzed. The research was conducted from January to December 2011 through a socio-anthropological study based upon an evaluative diagnosis, with semi-structured interviews, ethnography, observations, and collection of training materials. The information was synthesized in tables, considering the points of view of livestock farmers, representatives from the institutions supporting the training and the training team. The analysis focused on the background, topics, methods, results and expectations of the training. Results showed that farmers and representatives of the different institutions perceived few changes in livestock systems as a consequence of the training given in the context of BIRESE. However, farmers stated that there were some changes in the system, for example, the increase of production as an indirect result of the training received. Both the farmer groups and the representatives of the institutions are optimistic for the future and acknowledge that cattle raising can be done in an environmental friendly way. The reason of this perception is the permanent presence of actors promoting sustainable livestock. Farmers consider adopting the acquired practices as a very important issue, although they refer to lack of financial resources and technical assessment as the main limitations for its implementation. It is concluded that the perceptions on training are very similar among all actors involved in the BIRESE, which can be considered as an advantage for the initiatives or processes to be encouraged at short and middle terms in relation to sustainable livestock.

Manufacturing small and medium-sized enterprises (SMEs) are drivers for economic and social development. Their importance and competitive challenges are increasing interest and attention on private and public sectors due to hyper-competition environment. In order to establish an environment that, not only, addresses hyper-competition but also sustainability, a Meta-Organization is proposed to support advanced manufacturing business models, namely, Virtual and Ubiquitous Enterprises. This Meta-Organization is organizational platform supported by information and communication technologies (ICT), such as Web 3.0.

This article proposes a framework for the study of interactions between human societies and the natural world in the Isthmus of Panama, and the consequences of these interactions over time. It also wants to encourage a new reading of the best-known sources and authors associated with this issue – from the reports of early Spanish travelers to the writings of contemporary specialists such as Dolores Piperno, Richard Cooke, Omar Jaén Suárez, and Alfredo Castillero Calvo –, as well as the adoption of a new perspective on the deep origins of the environmental problems the country faces today. After a general characterization of the Isthmus’ ecoregions, the author proposes a historical periodization reflecting successive human strategies of interaction with the natural world, differentiated in terms of the technologies employed and the corresponding social relations; the expression of these strategies in environmental culture and values; modes of land management; and the impact of all this on the natural world. Special attention is given to the ecological footprint of interoceanic transit from the 16th century onward, and to the search of alternatives allowing more sustainable ways of relating to nature in Panama.

Candida rugosalipase was immobilized on poly(N‐methylolacrylamide) by physical adsorption. The biocatalyst performance (immobilized lipase) was evaluated in both aqueous (hydrolysis) and organic (butyl butyrate synthesis) media. In the first case, a comparative study between free and immobilized derivatives was provided in terms of pH, temperature and thermal stability following the olive oil hydrolysis, establishing new optimum values. In the second case, the influence of temperature, biocatalyst concentration and acid/alcohol molar ratio was simultaneously studied according to a 23full experimental design. The highest molar conversion (96 %), volumetric productivity (1.73 g L–1h–1) and specific esterification activity (1.00 μM mg–1min–1) were obtained when working at the lowest level of temperature and butyric acid in excess. Under these conditions, repeated batch use of the immobilized enzyme was performed and half‐life time (t1/2) was found to be 145 h.

Summary: A lipase from Candida rugosa immobilized on styrene-divinylbenzene copolymer was used to catalyse the direct esterification of butanol and butyric acid. A factorial design was employed to evaluate the effects of temperature (37–50 C), substrate molar ratio of butyric acid to butanol (0.6 to 2.0) and enzyme amount (0.2–0.4 g) on the ester yield. The main effects were fitted by multiple regression analysis to a linear model and maximum ester yield could be obtained working at 41 C with 0.4 g of lipase. The mathematical model obtained, representing the ester yield has been found to describe adequately the experimental results. Under optimal conditions, concentration of 32.4 g butyl butyrate/l that corresponds to a yield of 75% was obtained.

Abstract: Seeds of Cucurbita maxima, C. moschata and their interspecific hybrids were used to evaluate the intrapopulational and interpopulational variation of their protein composition. Three immunoprecipitating systems common to all the studied samples were detected by the Ouchterlony technique. Fourteen protein bands were identified by polyacrylamide gel electrophoresis (PAGE) whereas 23 bands were identified by sodiumdodecylsulfate (SDS)-PAGE. Using Western blotting (WB) also 23 bands were detected. The Jaccard's index of similarity calculated from SDS-PAGE and WB varied between 91 and 100 % for all the compared pairs of samples. These results demonstrate a high uniformity in the protein composition of all the samples and do not allow for their clear characterization.

Human Immunodeficiency Virus type 1 Reverse Transcriptase (HIV-1 RT) is one of the most important targets for treatment of Acquired Immune Deficiency Syndrome (AIDS). It catalyzes the reverse transcription of HIV-RNA into a double stranded DNA, and the knowledge of its substrate specificity and catalytic mechanism has guided the development of several inhibitors widely used on current HIV/AIDS therapy. However, mutations in HIV-1 RT structure can lead to the emergence of drug-resistant virus strains. The goal of this review is to summarize relevant structural features of HIV-1 RT and its inhibitors in such a way that this cost-effective target in the development of new antiretroviral drugs is particularly highlighted.

High critical current density (jc) is one of the most important properties of high Tcsuperconducting thin films. Determining it is difficult especially in large films (2-3 inch). We propose a non-destructive and easy technique for measuring jc. From measurements of the magnetic moment in the middle of a superconducting film as a function of the external magnetic field, we calculate the macroscopic critical current density.

Chitin was funcionalized with hexamethylenediamine followed by glutaraldehyde activation, and its capacity to bind Candida rugosa lipase was investigated. The loading of 250 units g^-1 support showed to be effective, resulting in a uniform enzyme fixation with high catalytic activity. Both free and immobilized lipases were characterized by determining the activity profile as a function of pH, temperature, and thermal stability. For the immobilized lipase, the influence of the reaction temperature and substrate polarity in nonconventional biocatalysis was also analyzed. Production of butyl esters was found to be dependent on the substrate partition coefficient, which accounts the greatest value for the system butanol and butyric acid. The highest enzyme activity was found for the system butanol and caprylic acid at a reaction temperature of 40 °C. Under such conditions, the operational stability tests indicated that a small enzyme deactivation occurs after 12 batches, revealing a biocatalyst half-life of 426.7 h.

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ABSTRACTS:La Cuenca Hidrográfica del Canal de Panamá (CHCP) comenzó a tomar fonna con la construcción del Canal de Panamá (1904–1914), que integró las cuencas de los ríos Chagres y Grande que desembocan en a los Océanos Atlántico y Pacífico, respectivamente en un solo sistema hidráulico para suministrar el agua necesaria para la operación de las esclusas del Canal, por medio de un corte en las tierras altas de la región central del país, y del represado del Río Chagres. Para mediados de la década de 1930, el sistema fue complementado con un lago adicional, creado en la cuenca superior del Río Chagres para incrementar la capacidad de almacenamiento de agua del sistema. En 1999, los límites formales de la CHCP fueron establecidos por ley, agregándole segmentos de las cuencas de los ríos Indio, Caño Sucio y Cocié del Norte, todos los cuales corren de manera independiente hacia el Océano Atlántico, al noroeste del Canal. La construcción de la CHCP como un problema de gestión se inició con el Tratado del Canal de Panamá (1977), que obliga a la República de Panamá a garantizar la provisión de agua necesaria para operar el Canal y satisfacer la demanda de sus ciudades terminales. Esto llevó a crear varios Parques Nacionales, a la promoción de actividades de desarrollo sostenible, y al desarrollo de estudios de línea base, todo con el apoyo de USAID. Una Autoridad del Canal de Panamá (ACP) fue creada mediante una Reforma Constitucional en 1994, a la cual se le asignó la responsbailidad de administrar la CHCP. En 1997 fueron aprobados un plan de manejo de suelos para la Cuenca original, y una Ley Orgánica para la ACP. Por otra parte, y en particular desde 1999, se ha iniciaod un amplio debate nacional sobre el futuro de las relaciones entre el Canal y el resto del país, y el papel de la ACP en las mismas. En ese debate se ha hecho evidente que éxito en el manejo de la CHCP estará estrechamente relacionado con la promoción del desarrollo sostenible en todo el país, y que esto demanda superar tanto los remanentes de la vieja cultura colonial del enclave canalera, como las estructuras socioeconómicas inequitativas que se consolidaron al amparo de ese enclave.

Candida rugosa lipase was covalently immobilized on silanized controlled pore silica previously activated with glutaraldehyde in the presence of nonenzymatic proteins. This strategy is suggested to protect the enzyme from aggregation effects or denaturation that occurs as a result of the presence of silane precursors used in the formation of the silica matrix. The immobilization yield was evaluated as a function of the lipase loading and the additive type (albumin and lecithin) using statistical concepts. In agreement with the mathematical model, the maximum coupling yield (32.2%) can be achieved working at high lipase loading (450 units·g^-1 support) using albumin as an additive. In these conditions, the resulting immobilized lipase exhibits high hydrolytic (153.2 U·mg^-1) and esterification (337.6 mmol·g^-1·min) activities. The enhanced activity of the final lipase derivative is the sum of the benefits of the immobilization (that prevents enzyme aggregation) and the lipase coating by additives that increases the accessibility of active sites to the substrate.

Abstract: Thirty-two multiparous Holando argentino cows in mid lactation were randomly assigned to two treatments: control or HFF (hydrogenated fish fat) at Rafaela, 31° 11’ South, during summer 1997/1998, to evaluate the effect of using HFF as a supplement under grazing conditions. Animals in both treatments grazed an alfalfa pasture, and were confined from 1000 hours to 1700 hours daily in a shaded pen where water was provided ad libitum. During each milking, animals in the control group received 3.73 kg dry matter per cow each day (DM cow–1 day–1) concentrate (15% crude protein; 8.69 MJ energy for location/kg DM). Cows in the HFF group received 3.25 kg DM cow–1 day–1 concentrate, plus 0.200 kg DM cow–1 day–1 HFF. Both diets presented similar energy, protein and neutral detergent fibre contents. The trial was performed during a strong ”El Niño” event, which resulted in a total rainfall of 396.3 mm (80% higher than normal). The mean temperature was 23.7 (SD 3.2)°C and the mean temperature humidity index was 72.9 (SD 4.96). Production data were analysed using a completely randomised design with analysis of covariance. Supplementation with HFF produced an increase in daily milk production (26.4 (SD 2.46) l/cow compared to 23.9 (SD 2.68) l/cow for the controls; P<0.05). Milk fat production was higher for HFF (P<0.05): 941 (SD 96) g cow–1 day–1 as compared to controls, which yielded 846 (SD 95) g cow–1 day–1. Milk protein yields also differed significantly (P<0.05), the respective values for HFF and controls being 795 (SD 72) g cow–1 day–1 and 715 (SD 83) g cow–1 day–1. It was concluded that hydrogenated fish fat could be a good ingredient to sustain high yields and elevated maintenance requirements in a grazing system during hot conditions.

The internet is recognised as a very useful tool in several areas of our society. Education is the area where greater expectations have been generated. Nevertheless, due to the high cost of the development of completely new applications, there is a lack of effective tools to support learning processes. This article presents a study to bring well-recognised learning strategies to the world of the internet. We analyse collaborative learning strategies in order to implement them as applications on the internet. In this article, we present not only an example of such an application, Mapco Collaborative Concept Maps on the internet, but also its careful design leading to a methodology and eventually to a framework aimed at developing this kind of application.

Candida rugosa lipase was covalently immobilized on rice straw activated with glutaraldehyde using poly(ethylene glycol) (PEG) as the stabilizing agent. The effects of PEG molecular weight and enzyme loading were studied according to a full 2² factorial design. Higher immobilization yields (>70%) were attained when the lipase loading was 95 units/mg of dry support, independent of PEG molecular weight. All derivatives showed high hydrolytic and synthetic activities. This work provides preliminary results on the use of agricultural residues as a support matrix for immobilizing lipase and on the application of the resulting derivatives to butyl butyrate synthesis as a study model.

Two carbofuran-metabolizing Sphingomonasstrains, TA and CD, were isolated from soils with differing histories of exposure to carbofuran. These strains were compared with a previously described strain, Sphingomonassp. CFO6, with regard to growth rate, formation of metabolites, and plasmid content and structure. Extensive regions of similarity were observed between the three different plasmid systems as evidenced by cross hybridization. In addition, all three systems harbor IS1412, an insertion sequence (IS) element involved in heat-induced loss of carbofuran phenotype in CFO6, and heat-induced carbofuran deficient mutants of all three strains correlated with loss of IS1412. A carbofuran deficient mutant of TA generated by induction of IS elements was complemented by reintroduction of the wild-type plasmid, confirming the presence of genes required for carbofuran metabolism on this plasmid. Carbofuran metabolism in these three strains is clearly linked via plasmids of different numbers and sizes that share extensive common regions, and carbofuran-degrading genes may be associated with active IS elements.

Two carbofuran‐metabolizing Sphingomonasstrains, TA and CD, were isolated from soils with differing histories of exposure to carbofuran. These strains were compared with a previously described strain, Sphingomonassp. CFO6, with regard to growth rate, formation of metabolites, and plasmid content and structure. Extensive regions of similarity were observed between the three different plasmid systems as evidenced by cross hybridization. In addition, all three systems harbor IS1412, an insertion sequence (IS) element involved in heat‐induced loss of carbofuran phenotype in CFO6, and heat‐induced carbofuran deficient mutants of all three strains correlated with loss of IS1412. A carbofuran deficient mutant of TA generated by induction of IS elements was complemented by reintroduction of the wild‐type plasmid, confirming the presence of genes required for carbofuran metabolism on this plasmid. Carbofuran metabolism in these three strains is clearly linked via plasmids of different numbers and sizes that share extensive common regions, and carbofuran‐degrading genes may be associated with active IS elements.

AbstractThe introduction of 6-(p-bromobenzoylamino)caproyl radical in the methyl group of 2′-O-deoxythymidine is described. In vivoincorporation of this nucleoside to DNA was determined using a monoclonal antibody that recognized the radical.

Activity coefficients for sodium chloride in the NaCl + Na2SO4+ H2O ternary system were determined from emf measurements of the cell $${\text{Na}} - {\text{glass|NaCl}}\left( {m_{\text{A}} } \right),\;{\text{Na}}_{\text{2}} {\text{SO}}_{\text{4}} \left( {m_{\text{B}} } \right),\;{\text{AgCl}}\left( {\text{s}} \right){\text{|Ag}}$$ at 15, 25, 35, and 45°C and at total ionic strengths from 0.1 to 6 mol-kg−1. These activity coefficient were analyzed by using the Harned rule and the treatments of Scatchard–Rush–Johnson and Pitzer. The analysis of activity coefficients at “trace” concentration was also achieved and qualitatively interpreted by considering the ionic interactions that can take place in the mixed system. Finally, the excess Gibbs energy of the mixtures was calculated and qualitatively analyzed against the composition of the system.

Six bone marrow transplant patients with CMV viremia were treated with the acyclic nucleoside analogue [9‐2 Hydroxy‐1‐(hydroxymethyl) ethoxymethyl] guanine (ganciclovir). The treatment was started as soon as viremia was detected by rapid diagnostic methods, in order to prevent the appearance of severe symptoms and the evolution to interstitial pneumonia. Ganciclovir was given at the dose of 2.5 mg/kg body weight every 8 hours for 20 days. The results showed that ganciclovir was well tolerated with no major toxicity. Virus disappeared promptly from cultures. One patient only recurred after cessation of treatment. All the other patients had a prompt improvement of clinical symptoms, when these existed, and none of them relapsed or progressed to interstitial pneumonitis. These results show that ganciclovir is active against CMV in bone marrow transplant patients. Its early use may prevent lethal interstitial pneumonitis.

Heat resistance of Lactobacillus bulgaricus in skimmed milk at 62#&176;, 64#&176;, 65#&176; and 66#&176;C was studied. The response to increasing temperatures in this range was not linear, with temperatures at 65#&176;C and above giving a lower survival rate than would be predicted from experiments at lower temperatures. To identify sites of injury at these temperatures, chemical markers were used. Heating at 64#&176;C and below resulted in damage to the cytoplasmic membrane. At temperatures of 65#&176;C and above chemical markers also indicated damage in the cell wall and proteins. Using differential scanning calorimetry analysis of whole cells of Lact. bulgaricus seven main peaks were observed (l-51, m 1 -61, m 2 -73, n-80, p-89, q-100,r-112#&176;C). Three of these peaks (l r , m r and p r ) were the result of reversible reactions. Analysis of cell fractions identified the cell structure involved in giving rise to each of the three reversible peaks; l r , cell membrane lipids, m r , ribosomes, and p r , DNA. The evidence presented in this paper shows that irreversible reactions in the cell ribosomes are a critical site of damage in Lact. bulgaricus during heat stress in liquid media at 65#&176;C and above.

The synthesis of 6-ami no-5-nitro-4-thioxo-pyrimidines starting from the C-adducts of nitro-keteneaminals and acyl isothiocyanates is described.

Abstract: An ethanol process based on a gas-lift tower fermenter arrangement was used as a model system to show the strong dependence of reactor behavior on the developing chemical environment within the reactor. The reactor performance limits for realistic substrates—starch and molasses—are characterized and compared with those attainable on an ideal substrate, glucose.