Effects of self-assembly process of latex spheres on the final topology of macroporous silica

This paper surveys the topology of macroporous silica prepared using latex templates covering the submicrometric range (0.1-0.7 mu m). The behavior of latex spheres in aqueous dispersion has been analyzed by dynamic light scattering (DLS) measurement indicating the most appropriate conditions to form well-defined cubic arrays. The optical behavior of latex spheres has been analyzed by transmittance and reflectance measurements in order to determine their diameter and filling factor when they were assembled in bidimensional arrays. Macroscopic templates have been obtained by a centrifugation process and their crystalline ordering has been confirmed by porosimetry and scanning electron microscopy. These self-assembled structures have been used to produce macroporous silica, whose final topology depends on the pore size distribution of the original template. It has been seen that latex spheres are ordered in a predominant fcc arrangement with slipping of tetragonal pores due to the action of attractive electrostatic interactions. The main effect is to change the spherical shape of voids in macroporous silica into a hexagonal configuration with possible applications to fabricate photonic devices with novel optical properties. (c) 2005 Elsevier B.V. All rights reserved.

Evaluation of in vitro gas production of roughages and their mixtures using the curves subtraction method

The in vitro gas production of four single roughages and their paired combinations (1:1 on dry matter basis) were evaluated. Two roughage samples (100 mg) per treatment were fermented with ruminal fluid during a 48 h incubation period. Total 48 h gas volumes of fermentation dry matter (DM), neutral detergent fiber (NDF) and soluble compounds in neutral detergent (NDS) were for sugarcane = 16.8, 11.2, 6.9 mL; sugarcane + corn silage = 20.1, 12.6, 9.1 mL; sugarcane + 60-day elephantgrass = 16.5, 17.6 mL; sugarcane + 180-day elephantgrass = 13.8, 8.2, 5.9 mL; corn silage = 18.8, 16.8, 4.7 mL; corn silage + 60-day elephantgrass = 16.3, 15.4, 2.4 mL; corn silage + 180-day elephantgrass = 16.1, 11.8, 4.2 mL; 60-day elephantgrass = 16.9, 19.0 mL and 180-day elephantgrass = fermented 10.7, 12.2 mL, respectively. The NDS gas production was not possible to estimate for sugarcane + 60-day elephantgrass, 60-day elephantgrass and 180-day elephantgrass. The present data shows that the curves subtraction method can be an option to evaluate the contribution of the soluble fractions in roughages to digestion kinetics. However, this method underestimates the NDS gas contribution when roughages are low in crude protein and soluble carbohydrates. It is advisable to directly apply the two-compartmental mathematical model to the digestion curves for roughage DM, when determining the NDS gas volume and the digestion rate. This method is more straightforward and accurate when compared to the curve subtraction method. Non-structural carbohydrates combined with fiber and protein promoted a positive associative effect in sugarcane + corn silage (50:50) mixture. Therefore, it can be concluded that the soluble fraction of roughages greatly contributes to gas production. (C) 2004 Elsevier B.V. All rights reserved.

Performance of Cultivars for Production of Green Corn in Different Planting Dates in Passos Region, MG

The aim of this work was evaluating the performance of several cultivars of green corn for consumption 'in natura' in different planting dates. The first planting date was on May 26th, and the others, every 40 days. The hybrids (treatments) were: AG-1051, Agroeste 1567, BM-3061, Prezoto-32D10, PL-6880, BX-1382 and GNZ-2004. The following characteristics were evaluated: production, commercial ears weight without husk, commercial ears number, commercial ears diameter and length, male flowering, plant height and height of ear corn insertion. The cultivars AG1051, Agroeste 1567 and BM 3061 presented the best results compared to the others and they should be used in green corn production for ` in natura' consumption in Passos County, MG.

Evaluation of the components of production of the ricinus according of rates of calcareous rock and match

The soil of the Paraiba, in generality, are acid and with low levels of available match, seriously limiting the income of the plants. A research in vegetation house was lead, with the objective to evaluate doses of calcareous soil and match in the culture of ricinus. The treatments had been composites for five levels of match: 0.0; 80; 160; 240 and 360 kg ha(-1) of P(2)O(5) and four dosis of calcareous rock: 0.0; 2.5; 3.5 and 4.5 t ha(-1) in experimental delineation of blocks casualized with 4 factorial project x 3 (four levels of match and three doses of calcareous soil) more two treatments you add zero of match (0.0 P(2)O(5): 2,5 t ha(-1) of calcareous soil) and calcareous soil zero (240 P(2)O(5): 0.0 t ha(-1) of calcareous soil), with three repetitions. The calcareous soil reduced the acidity of the ground and effect of the application of the match (>= 80 kg ha(-1) of P(2)O(5)) in the presence of the collagen (>= 2.5 t ha(-1) of CaCO(3)) with of the calcareous soil (>= 2.5 t ha(-1) of CaCO(3)) in the presence of the match was not verified well (>= 80 kg ha(-1) of P(2)O(5)). The match applied in the absence of the calcareous soil was limited to the income of the culture of what the calcareous soil in the absence of the match.

Population dynamics of Leptopharsa heveae (Hemiptera: Tingidae) and Erythmelus tingitiphagus (Hymenoptera: Mymaridae) in rubber tree plants

The tingid Leptopharsa heveae, known as the lace bug, occurs in large populations in rubber tree plantations, limiting the production of latex due to losses of photosynthetic area and weakening of the infested trees. The alternative for the use of insecticides would be the release of biological control agents, but little is known about the natural enemies of L. heveae. The parasitoid Erythmelus tingitiphagus parasitizes eggs of the lace bug in rubber tree plantations. The knowledge of the population dynamics and the peak of occurrence of economically important insect species and their natural enemies are indispensable requirements for the establishment of efficient and rational control strategies. The objective of this work was to study the population dynamics of L. heveae and E. tingitiphagus in rubber tree plantations in the county of Itiquira, MT, Brazil. Mature folioles were collected weekly from the lower stratum of the canopy of the tree clones RRIM 600, PR 255, GT 1, PB 235 and PB 217, from August/2005 to February/2006. The parasitoid was observed during the whole study period. The population peaks of the populations of the L. heveae and E. tingitiphagus in the study area occurred at the end of October and beginning of November. This result demonstrates that measures for the control of L. heveae and population increase of E. tingitiphagus must be adopted before the peak population of this pest in cultivated rubber plantations.

A Review on the Challenges for Increased Production of Castor

Castor (Ricinus communis L.) is one of the oldest cultivated crops, but currently it represents only 0.15% of the vegetable oil produced in the world. Castor oil is of continuing importance to the global specialty chemical industry because it is the only commercial source of a hydroxylated fatty acid. Castor also has tremendous future potential as an industrial oilseed crop because of its high seed oil content (more than 480 g kg(-1)), unique fatty acid composition (900 g kg(-1) of ricinoleic acid), potentially high oil yields (1250-2500 L ha(-1)), and ability to be grown under drought and saline conditions. The scientific literature on castor has been generated by a relatively small global community of researchers over the past century. Much of this work was published in dozens of languages in journals that are not easily accessible to the scientific community. This review was conducted to provide a compilation of the most relevant historic research information and define the tremendous future potential of castor. The article was prepared by a group of 22 scientists from 16 institutions and eight countries. Topics discussed in this review include: (i) germplasm, genetics, breeding, biotic stresses, genome sequencing, and biotechnology; (ii) agronomic production practices, diseases, and abiotic stresses; (iii) management and reduction of toxins for the use of castor meal as both an animal feed and an organic fertilizer; (iv) future industrial uses of castor including renewable fuels; (v) world production, consumption, and prices; and (vi) potential and challenges for increased castor production.

Influence of HLA-DRB-1 alleles on the production of antibody against CSP, MSP-1, AMA-1, and DBP in Brazilian individuals naturally infected with Plasmodium vivax

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)