A new alternative for estimating recommendations of protein intake in humans. Protein requirements of an adult population fed with a diet based on rice and beans

This paper proposes a new approach to estimate the protein needs of a population; recommendations are also made on the protein intake of adults fed diets based on rice and beans. For this purpose, the nitrogen balance data previously reported for 40 adult human subjects who had participated in 160 nitrogen balance periods fed diets based on rice and beans, with and without animal protein and/or energy supplementation were used. The proposed method is based on the curvilinear response between nitrogen intake and its nitrogen balance. The second degree equation describing the relationship between nitrogen balance and intake is calculated. Using the mathematical concept of the first and second derivatives, the point of inflexion is obtained, and interpreted as that condition wherein the individual utilizes with maximum efficacy the ingested nitrogen; nitrogen ingestion, which corresponds to that point, is therefore taken as the dietary nitrogen recommendation for the individual. When the values obtained by means of the quadratic equation are compared to those obtained by the traditional linear equation, values were found to be statistically equal (p less than 0.05) for both calculation methods. The recommended protein intake of an adult population fed a diet based on rice and beans was 0.80 and 0.77 g/kg/day for the quadratic approach, and for the conventional method, respectively. When this diet was supplemented with 10% milk protein and with the same energy level, the calculated values were 0.64 and 0.71 g protein/kg/day for both methods, in this same order. The essential amino acid intake and absorption values were also calculated from the protein levels recommended by both methods to be in nitrogen balance, from a diet based on rice and beans. Findings revealed, in all cases, that the intakes of each and all essential amino acids met those levels indicated by FAO/WHO, with the exception of isoleucine and the sulphur-containing amino acids, which apparently limit the quality of the diet.     

Electrochemical determination of pharmaceuticals in spiked water samples

The electrochemical behaviour of acidic and neutral pharmaceutical active compounds (PhACs) was studied by cyclic voltammetry and pulse voltammetric techniques on mercury, carbon nanotube paste, carbon paste and gold electrodes. The best results, in terms of sensitivity, linearity range and detection limits, were obtained by differential pulse voltammetry (DPV) for ofloxacin (LOD 5.2 microM), differential pulse polarography (DPP) for clofibric acid (LOD 4.7 microM) and normal pulse voltammetry (NPV) for diclofenac (LOD 0.8 microM) and propranolol (LOD 0.5 microM). An enrichment step of approximately two orders of magnitude was performed by a solid-phase extraction procedure (SPE) in order to concentrate the samples. The developed method was optimized and tested on spiked river water samples.     

Economic development in Appalachia

Summary The policy pattern for maximizing income growth indicated by this analysis stresses rural education and an extension of livestock farming coupled with less overall reliance on agriculture, and a reduction in tenancy. Efforts to gear the rate of mechanization of agriculture to the capacity of local industrialization to employ those released by agriculture also appear indicated.The authors are respectively Economist of the Human Resources Research Center, University of Southern California, and Professor of Economics, University of Maryland. They are indebted to the Center for Advanced Study in Behavioral Science and to the Agency for International Development for support of this research.     

Effect of catecholamines and β-blockers on linoleic acid desaturation activity

The effect of catecholamines and adrenergic blocking agents on the oxidative desaturation of linoleic acid in rat liver microsomes was studied. Epinephrine (1 mg/kg/body weight) produced a significant decrease on the conversion of [1-¹⁴C]linoleic acid to γ-linolenic acid. The effect of epinephrine was blocked by single injections of the β blockers propranolol (10 mg/kg body weight) or dichloroisoproterenol 30 min before the hormone treatment. Isoproterenol (100 μg/kg body weight) produced a significant decrease on the activity of the linoleyl-CoA desaturase. The effect of the catecholamines was postulated to be mediated through β receptors by an enhancement of the intracellular levels of cyclic AMP.     

Sensing properties of asymmetric double-layer-covered tapered fibers

A novel, to our knowledge, device based on a tapered optical fiber with a double-layer deposition including a metallic media is presented, and its properties are studied. The main novelty of the device consists of the introduction of a dielectric layer, whereas the systems depicted in the literature are simply metal-coated tapered fibers. The presence of the dielectric layer permits one to tune the response of the device to the refractive index of the surrounding medium. We have proved the suitability of this scheme for refractive-index sensing by depicting two measurement modes, namely, total power attenuation and spectral transmittance.     

Modeling electric-field-sensitive scanning probe measurements for a tip of arbitrary shape

We present a numerical method to model electric-field-sensitive scanning probe microscopy measurements which allows for a tip of arbitrary shape and invokes image charges to exactly account for a sample dielectric overlayer. The method is applied to calculate the spatial resolution of a subsurface charge accumulation imaging system, achieving reasonable agreement with experiment.     

Transgenic cotton plants with increased seed oleic acid content

Cottonseed typically contains about 15% oleic acid. Here we report the development of transgenic cotton plants with higher seed oleic acid levels. Plants were generated by Agrobacterium-mediated transformation. A binary vector was designed to suppress expression of the endogenous cottonseed †-12 desaturase (fad2) by subcloning a mutant allele of a rapeseed fad2 gene downstream from a heterologous, seedspecific promoter (phaseolin). Fatty acid profiles of total seed lipids from 43 independent transgenic lines were analyzed by gas chromatography. Increased seed oleic acid content ranged from 21 to 30% (by weight) of total fatty acid content in 22 of the primary transformants. The increase in oleic acid content was at the expense of linoleic acid, consistent with reduced activity of cottonseed FAD2. Progeny of some lines yielded oleic acid content as high as 47% (three times that of standard cottonseed oil). Molecular analyses of nuclear DNA from transgenics confirmed the integration of the canola transgene into the cotton genome. Collectively, our results extend the metabolic engineering of vegetable oils to cottonseed and should provide the basis for the development of a family of novel cottonseed oils.     

Effect of the use of a commercial phosphate mixture on selected quality characteristics of 2 Spanish-style dry-ripened sausages

Abstract: The aim of this study was to evaluate the usefulness of the addition of a commercial phosphate mixture in 2 dry‐ripened Spanish‐style sausages: “salchichón” and “chorizo.” Three batches of each of those sausages were prepared with low and high levels of phosphates, and selected quality variables (moisture, pH, a_w, lactic and acetic acid, α‐amino nitrogen, total free fatty acids, thiobarbituric acid reactive substances, microbial counts, color, and texture analysis) were compared against controls. Furthermore, phosphate‐added and control sausages were ranked by consumers in order of preference. In “salchichón,” phosphate addition resulted in a significant (P < 0.05) increase in drying rate, and tendencies (not significant) toward a decrease in lipid oxidation and an increase in hardness and chewiness. In “chorizo,” the addition of phosphates resulted in higher hardness, elasticity and chewiness, and lower yellowness (P < 0.05). In the manufacture process of dry‐ripened sausages, phosphates can be considered as additives with potential enhancement effect in drying and eating quality. Practical Application: The main outcome from the present study is to find evidence on which points of reference could be drawn for the technological application of phosphates in dry‐ripened sausages. It has been observed that the drying rate and several eating quality characteristics can be enhanced with the use of phosphates.