Effect of lactobacilli inoculation on cassava (Manihot esculenta) silage: Fermentation pattern and kinetic analysis

The major effect of Lactobacillus inoculation on laboratory cassava (Manihot esculenta Crantz) silage was a change from a heterofermentative pattern observed in natural silage to a homofermentation. Small amounts of starter culture (1% v/w) were required to produce a high level of lactic acid (> 28 g kg^?1 DM) and to reach a pH of at least 4. The Gompertz model was used to evaluate the effect of inoculation level on the lactic formation based on kinetic criteria. Also an empirical pH lactic acid correlation was proposed to monitor the progress of ensiling, based solely on pH measurements. The simulation model may be used to improve guidelines for silo safety and to evaluate the effect of lactobacilli inoculants.     

Atypical antipsychotic medications: Pharmacological profiles and psychological implications.

Advances in psychopharmacology and the development of new antipsychotic medications may represent increased opportunities for psychologists to provide expanded psychosocial services to patients with schizophrenia. The new agents, referred to as the atypical antipsychotics, are as efficacious as the older conventional antipsychotics but demonstrate a more favorable side effect profile. Preliminary data suggest improvements in cognitive deficits and negative symptoms typically associated with schizophrenia, which may enhance long-term outcome. Psychologists may be increasingly called on to provide psychosocial services to this population, thereby requiring that they have a sound working knowledge of the pharmacological and psychological properties of these agents. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

On the coordinator's rule for Fast Paxos

Fast Paxos is an algorithm for consensus that works by a succession of rounds, where each round tries to decide a value v that is consistent with all past rounds. Rounds are started by a coordinator process and consistency is guaranteed by the rule used by this process for the selection of v and by the properties of process sets called quorums. We show a simplified version of this rule for the specific case where the quorums are defined by the cardinality of these process sets. This rule is of special interest for implementors of the algorithm.     

Confined melting in deformable porous media: A first attempt to explain the graphite/salt composites behaviour

This paper deals with phase change in composite materials made of graphite and a phase-change material (PCM). The composites are manufactured by compressing a solid mixture of salt and graphite particles. In previous works, the interest of such materials for thermal energy storage at high temperature has been highlighted. They are characterized by quite high energy storage capacity as well as high thermal conductivity. However, first melting/crystallization of these composites could lead to significant salt leakage and shows some a priori unexpected features like melting over a range of temperature instead of at constant temperature and significant loss of heat storage capacity. A poro-thermo-elastic analysis is carried out in this paper for understanding salt melting within the graphite matrices and for proposing reliable ways for composite materials improvement. An intentionally simple think-model, based on mass and energy conservation equations, pressure-dependent liquid–crystal equilibriums, linear elasticity laws and Poiseuille-like flow, is proposed. In spite of the simplicity, the model turns out to be apt to explain main macroscopic features of materials melting as observed in calorimetric tests. The influence on melting dynamics of parameters like the heating rate, the pore-wall rigidity and thickness, the salt volume expansion and the pore connectivity is investigated and several ways for composite materials improvements are discussed.     

Tracking human faecal contamination in tropical reservoirs in Puerto Rico

Using a combination of chemical and microbiological (culture-dependent and -independent) approaches, sources of human faecal contamination were identified in two water reservoirs in Puerto Rico – Guajataca and La Plata. Fluorescence from optical brighteners (OB) – commonly found in laundry detergents – was used as an indicator of contamination from septic systems and other household discharges. Traditional indicators of faecal contamination (e.g. Escherichia coli; faecal enterococci) were enumerated, and human faecal contamination was confirmed through detection of Bifidobacterium adolescentis utilizing polymerase chain reaction (PCR)-based analyses. For Guajataca Reservoir, four of 19 sampling sites (21%) were positive for the presence of B. adolescentis under baseflow conditions. The OB fluorescence data suggested that the most likely source for three of these sites was residential, whereas the source of contamination at the remaining site, although of human origin, was probably non-residential. B. adolescentis was present in 83% (19 of 23) of the sampling sites in La Plata. The La Plata sources were more difficult to identify because samples were taken under stormflow conditions, although the presence of OB fluorescence suggested a residential origin in a number of instances. OB fluorescence and traditional bacterial indicators of faecal contamination produced a number of false positive and negative findings for both reservoirs, pointing to the importance of understanding the limitations of these tools for tropical freshwater systems. The results of this study should be useful in developing a weight-of-evidence approach for the identification of potential sources and extent of human faecal contamination in similar tropical reservoirs, a necessary step in the development of management plans to reduce or eliminate these sources.     

Ultra-deep oxidative desulfurization of diesel fuel by the Mo/Al2O3-H2O2 system: The effect of system parameters on catalytic activity

This work presents the results obtained in the development of Mo/γ-Al₂O₃ catalysts and their evaluation in the oxidative desulfurization (OD) process of diesel fuel using hydrogen peroxide as the oxidizing reagent. The catalysts were prepared by equilibrium adsorption using several molybdenum precursors and aluminas with different acidity values. They were characterized by Raman spectroscopy. The effect of the reaction time, reaction temperature, nature of solvent, concentration of solvent and hydrogen peroxide, content of molybdenum and phosphate in the catalysts were investigated. The results showed that the activity for sulfur elimination depends mainly on the presence of hepta- and octamolybdates species on the catalyst support and the use of a polar aprotic solvent. Likewise, the presence of phosphate markedly increases the sulfur elimination. In this way, it is possible to reduce sulfur level in diesel fuel from about 320 to less than 10 ppmw at 333 K and atmospheric pressure. Additionally, on the basis of the results obtained a mechanistic proposal for this reaction is described, as an oxidation mechanism by nucleophilic attack of the sulfur atom on peroxo species of hepta- and octamolybdates, but a mechanism involving the singlet oxygen presence can be discarded.     

Collapse of conical cavities in aluminium metal under shock wave impact

Under shock wave impact the conical free surface of the metal collapses and a metallic jet with a velocity exceeding 10 km/s is squirted out of the metallic target. Variation in the jet tip velocity when the cavity half angle ranges from 60 down to 7.5° has been studied over three different shock pressures. The jet velocity has been found to increase with the decrease in the angle of the conical free surface and as the angle approaches zero the jet tip velocity attains a value near to the limit set by hydrodynamic theory for non-compressible fluids. The effect of aerodynamic drag on this type of jet has been studied and it has been found that the jet formed by the collapse of a small angle conical cavity quickly slows down while travelling in air, whereas the jet coming out of large angle cavity suffers a small retardation. Theoretical explanation and experimental evidence in support of this fact are also presented.     

Botanical features for identification of Gymnosporia arenicola dried leaf

Gymnosporia arenicola Jordaan (Celastraceae) is a shrub or small tree, which naturally occurs in coastal sand dunes of Southern Mozambique and South Africa. Its dried leaf is often used in traditional medicine for the treatment of infectious and inflammatory diseases. Hereby, we present results of studies carried out according to the pharmacopoeia standards for the identification of herbal drugs, in the whole, fragmented, and powdered plant material. These results were complemented with scanning electron microscopy and histochemical techniques. The leaf microscopic analysis revealed a typical dorsiventral mesophyll with a corresponding spongy parenchyma–palisade parenchyma ratio of 0.60, anomocytic and paracytic stomata, papillate cells with a diameter of 4.00 ± 0.40 µm, multicellular uniseriate nonglandular trichomes with a length of 27.00 ± 4.10 µm and cristalliferous idioblasts containing calcium oxalate cluster crystals with a diameter of 23.04 ± 5.84 µm. The present findings demonstrate that the G. arenicola leaf has both nonglandular trichomes and hypoderm, features not previously described in the corresponding botanical section (Gymnosporia sect. Buxifoliae Jordaan). The establishment of these new botanical markers for the identification of G. arenicola leaf is essential for quality, safety and efficacy reasons. Microsc. Res. Tech. 78:1001–1009, 2015. © 2015 Wiley Periodicals, Inc.     

Aflatoxin M1 in pasteurized and ultrapasteurized milk with different fat content in Mexico

High per capita milk consumption in Mexico indicated a strong need for documentation of aflatoxin M1 (AFM1) levels in milk. A survey of 580, 2-liter samples (n = 290), was conducted to quantify AFM1 using high-performance liquid chromatography, considering two maximum tolerance levels (0.05 and 0.5 microg/liter). We relate aflatoxin levels in the seven most consumed brands from different regions, with two processes (pasteurized and ultrapasteurized), different expiration dates, and different fat content: whole fat (28, 30, and 33 g), half-skimmed (10, 16, and 20 g), light (1, 2, and 4 g), and with vegetable oil. Pasteurization and ultrapasteurization did not diminish AFM1 contamination present at levels of 0 to 8.35 microg/liter in 40% of the milk samples at concentrations > or = 0.05 microg/liter and in 10% of the samples at > or = 0.5 microg/liter. Statistically significant relationships were AFM1 contamination with brand (P = 0.002 at the > or = 0.05 microg/liter level and P = 0.034 at the > or = 0.5 microg/ liter level) and higher AFM1 levels with mild or warm seasons of the year (P = 0.0003). Samples with greater fat content had slightly more probability (P = 0.067) of being contaminated by AFM1 at the > or = 0.5 microg/liter level. The milk with the lowest contamination of AFM1 was a brand imported as powder and rehydrated in Mexico.