Influence of components of infant formulas on in vitro iron, zinc, and calcium availability

The effect of casein content and Ca concentration on Fe, Zn, and Ca dialyzability was assessed using a response surface design. Tested casein levels were 5.31-13.75 g/L (34.8-90.2% of total protein). Whey protein was added to complete 15.25 g/L total protein. Calcium levels were adjusted with calcium citrate within a range between 417.4 and 804.9 mg/L. Through the experimental design utilized, we found that of both assessed factors, only the casein content significantly influenced Fe and Zn dialyzability. Protein composition did not influence calcium dialyzability, and calcium concentration did not affect either Fe or Zn dialyzability. No effect of casein-Ca on iron, zinc, and calcium dialyzability was found. According to these results, whey-dominant formulas are less prone to hamper mineral availability, and are therefore suitable in order to improve iron and zinc availability.     

Comparative Analysis of Native <Emphasis Type="Italic">Crocus</Emphasis> Taxa as a Great Source of Flavonoids with High Antioxidant Activity

Native Crocus taxa are abundant in regions with moderate and dry climate; however, their potential in the food industry has thus far been neglected. The objective of this study was to compare the quantitative and qualitative flavonoid content and antioxidant and cytotoxic activity in organs of several populations of Croatian native taxa and assess their potential for application in the food industry. The dominant flavonoids in the native Crocus taxa were kaempferol and quercetin. Tepals contained similar or higher concentrations of flavonoid-glycosides than other organs. Tepals from Cvv1 and Cvv2 populations contained more flavonoid-glycosides than the commonly used spice saffron (C. sativus stigmas). The FRAP antioxidant activity of Cvv1 and Cvv5 tepals was similar to that of standard Trolox. DPPH inhibition of Cvv1 and Cvv3 tepals was within the range of that recorded for saffron. Cvv1 tepals significantly reduced reactive oxygen species in the broadest concentration range (50–1000 μg/ml), and showed considerable antioxidant activity in the ABTS assay, equal to 82% of standard Trolox antioxidant activity. A significantly higher concentration of kaempferol-rutinoside was recorded in this than in other taxa. The flavonoid showed a very strong or strong correlation with antioxidant assays results, and a negative correlation with cellular reactive oxygen species concentration. We therefore presumed that kaempferol-rutinoside is one of the main antioxidant phenolics in Crocus tepals. None of the tested extracts showed cytotoxicity toward Caco-2 cells. The results revealed that Cvv tepals have potential as a food supplement and are a promising material for further food safety tests.     

Timber investment returns for selected plantations and native forests in South America and the Southern United States

Timber investment returns were estimated for the principal exotic and selected native species in the Southern Cone of Latin America and in the Southern United States. Exotic eucalyptus plantations in South America were most profitable, with internal rates of returns (IRRs) ranging from 13% to 23%, followed by exotic loblolly pine, with IRRs from 9% to 17%. Average loblolly pine plantation returns in the US South were less profitable, with an IRR of about 9.5%, and natural forest management in the South had IRRs of 4% to 8%. Subtropical native species plantations of the best araucaria and nothofagus species had reasonable financial returns, with IRRs ranging from 5% to 13%. Subtropical or tropical native forests had fewer commercial timber species, and had much lower growth rates and returns. Their IRRs were less than 4%, or even negative for unmanaged stands. State subsidy payments for forest plantations or for timber stand improvements increased IRRs somewhat and reserving areas for environmental protection reduced their IRRs slightly. Including land costs in the cash flows decreased these internal rates of return substantially. Natural stand returns in Latin America were much less than those of plantations, but management of those stands offered better rates of return than only holding the land.     

Mineral dialyzability in milk and fermented dairy products fortified with FeNaEDTA

Iron, zinc, and calcium dialyzability and ascorbic acid (AA) concentrations were evaluated in milk and yogurt fortified with FeNaEDTA (FE) or ferrous sulfate (FS) as a control, with or without AA addition. The values obtained for FE iron dialyzability in milk were much higher than those obtained for FS. The addition of AA to milk improved Fe dialyzability when using FS and slightly decreased Fe dialyzability in the FE-fortified nonfermented samples. Milk fermentation increased iron availability from both iron sources. Zinc and calcium dialyzability in products containing any of the two iron sources was increased in fermented milks. EDTA improved Zn dialyzability from intrinsic zinc in every manufactured dairy product. Whereas for milks fortified with FS and stored at 4 degrees C for 24 h, the AA content remained close to the original concentration, a higher AA degradation was observed when milks were fortified with FE.     

Plant recovery of cryopreserved apical meristem-tips of Melia azedarach L. using encapsulation/dehydration and assessment of their genetic stability

A cryopreservation process usingencapsulation/dehydration technique was setup for apical meristem-tips of invitro plantlets of `paradise tree' (Melia azedarach L. var. gigantea,clone `El dorado'). Apical meristem-tipswere cultured for one day on MS basalmedium with 2 M BA and 0.5 M IBAand encapsulated with 3% sodium alginate.The highest shoot proliferation rate aftercryopreservation was obtained whenencapsulated apical meristem-tips werepregrown for 3 days in liquid medium with0.5, 0.75 and 1 M of sucrose for 24 hoursprogressively, desiccated for 5 hours withsilicagel followed by rapid or slowcooling. Survival after freezing in liquidnitrogen ranged between 67–83% andshoot proliferation ranged between 43–60%. This cryopreservation treatmentpreserved genetic stability, when it wasevaluated using the electrophoreticpatterns of nine isozyme systems and RAPDprofiles.     

Symptoms and transmission of potato deforming mosaic of Argentina

Summary Potato deforming mosaic (PDM), known since about 1950, is increasing in importance and nn the main potato growing area of Argentina it is numerically at least as important as potato leaf roll virus and virus Y. It has not been reported from other parts of the world. The symptoms consist of large irregular chlorotic spots accompanied by leaf deformations. In older plants, a general chlorosis and a reddish discolouration can occur. Synergistic symptoms are produced by mixed infection with virus X. Plants tend to be smaller and weaker when co-infected by virus Y. Primarily infected plants can produce healthy as well as diseased tubers and some tubers may be only partly infected. In the latter case the eyes next to the stolon end are more likely to be disease-free than the others. Occasionally, secondarily infected plants can produce some tuber eyes which escape infection and give rise to healthy plants. Attempts to transmit the disease mechanically or by three aphid species and the eriophyid miteAculus lycopersici have failed. Control measures should aim at producing seed potatoes with a low infection rate. There are cultivar differences in susceptibility.

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Zusammenfassung Das deformierende Mosaic (PDM) der Kartoffel, das etwa seit 1950 bekannt ist, nimmt im argentinischen Kartoffelbau stetig an Bedeutung zu; in den Hauptanbaugebieten ist es anteilm?ssig wenigstens so bedeutungs-voll wie das Blattroll- und das Y-Virus (Tabelle I). Die durch das PDM verursachten Verluste liegen zwischen 20 und 30 %; in anderen Teilen der Welt ist diese Krankheit bisher nicht beobachtet worden. PDM kann mit dem Pflanzgut (Knollen) und durch Pfropfen weiter verbreitet werden. Versuche, das Virus mechanisch durch Pressaft auf Kartoffeln oder andere Solanaceen zu übertragen, schlugen — auch unter Zuhilfenahme flüssigen Stickstoffs fehl. Desgleichen konnte die Krankheit nicht durch die Kartoffelblattl?useMyzus persicae, Macrosiphum euphorbiae undAulacorthum solani und durch die freilebende GallmilbeAculus lycopersici übertragen werden. Die Symptome an Kartoffelpflanzen bestehen aus grossen unregelm?ssigen chlorotischen Blattflecken und Blattdeformationen (Abb. 1). ?ltere Pflanzen k?nnen sp?ter stark chlorotisch und r?tlich verf?rbt sein. wobei die Intensit?t der Symptomauspr?gung je nach der Kartoffelsorte schwankt und im Gew?chshaus deutlicher als im Freiland ist. Mischinfektion mit dem X-Virus führt zu Stauchung der Pflanzen, kr?ftiger Missibildung und Rauheit des Blattes, zu einem ausgepr?gten Mosaik und zahlreichen nekrotischen Flecken auf der oft brüchig werdenden Blattfl?che (Abb. 2). Eine ?hnliche synergistische Reaktion kann auch bei Mischinfektion mit dem Y-Virus beobachtet werden. In übertragungsversuchen zur Kl?rung der übertragungsm?glichkeit des PDM durch die Knollen ergab sich, dass prim?r infizierte Kartoffelpflanzen gesunde und PDM-kranke Knollen hervorbringen, dass auch nur teilinfizierte Knollen an ihnen entstehen k?nnen. Im letzteren Falle sind gew?hnlich die dem Stolon n?heren Augen virusfrei. Gelegentlich k?nnen sogar an sekund?r infizierten Pflanzen einige Augen der Infektion entgehen. Da Sortenunterschiede in der Anf?lligkeit gegen PDM-Infektionen bestehen, sollte die Bek?mpfung des Virus vorwiegend auf die Erzeugung von Pflanzkartoffeln mit geringen Infektionsanteilen ausgerichtet sein (Tab. 1).

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Résumé La mosa?que déformante de la pomme de terre (PDM) a été observée pour la première fois en Argentine vers les années 1950. Depuis cette période, son importance a augmenté dans la plupart des surfaces cultivées en pommes de terre de l'Argentine; elle est numériquement aussi importante que les virus Y et de l'enroulement (tableau 1). Les pertes totales provoquées par PDM sont élevées: les plantes malades ont un rendement inférieur de 20 à 30% à celui des plantes saines. La maladie n'est pas signalée dans les autres parties du monde. Le PDM est transmis par le tubercule de semence et par la greffe. En dépit de nombreuses tentatives, la transmission par la sève n'a p? être mise en évidence et le vecteur n'est pas connu. Des expériences de transmission mécanique de la maladie à la pomme de terre et à d'autres espèces de Solanacées n'ont pas abouti; il en est de même d'expérimentations de transmission avec de l'azote liquide. Des essais de transmission par les aphidesMyzus persicae, Macrosiphon euphorbiae etAulacorthum solani et par l'eriophyidAculus lycopersici n'ont pas donné de résultats. Les sympt?mes se manifestent par l'apparition de larges taches chlorotiques et irrégulières accompagnées de déformations du feuillage (fig. 1). Sur des plantes agées, une chlorose générale et une décoloration rougeatre peuvent s'observer. Les sympt?mes sont différents en intensité selon le cultivar, ils sont plus atténués au champ qu'en serre. Une infection conjointe avec du virus X provoque une maladie grave, c'est à dire un rabougrissement de la plante, une déformation intense de la feuille qui devient rugueuse, une mosa?que prononcée et de nombreuses taches nécrotiques sur le limbe qui peut alors se déchirer (fig. 2). Une synergie analogue peut s'observer avec le virus Y, les plantes devenant plus petites et affaiblies. Des essais de transmission par le tubercule montrent que des plants de pommes de terre primitivement infectés peuvent produire des plants sains aussi bien que des tubercules malades, et quelques tubercules peuvent être seulement partiellement infectés. Dans le dernier cas, les yeux situés près de l'extrémité de stolon semblent être davantage indemnes de maladies que les autres. Parfois, des plants infectés secondairement peuvent présenter des germes qui échappent à l'infection et donnent des plantes saines. Le but des mesures de contr?le devrait porter sur la production de semences de pommes de terre présentant un taux faible d'infection. Il existe des différences de sensibilité variétale (tableau 1).

     

Determination of Water Fluoride Concentration and the Influence of the Geographic Coordinate System and Time

The upper limit of fluoride concentration in water for human consumption is 1.5?ppm. Many studies have been carried out concerning the water fluoride concentration in wide areas around the world, but none have studied the change of fluoride concentration as a function of geographical coordinates and through time. This paper describes ??microvariation?? of fluoride concentration among wells separated by less than 500?m in a month. On the other hand, ??macrovariation?? is also studied describing changes among cities that are separated by more than 10?km and compared with fluoride concentrations measured 65?years ago. Fluoride concentration was measured in a wide geographical area of Argentina, which is 133,000?km². Samples of water were collected from different regions. Macrovariation: Differences in fluoride concentration in well water among regions were found, as well as an increase in water fluoride concentration during seven decades. Microvariation: Daily water fluoride concentration in a specific area displayed a great variation in the measurements through time. In addition, wells with no more than 500?m of separation were measured at the same time and were significantly different. These results indicate that in order to determine the fluoride concentration of a region, different samples of the same area should be obtained and a sampling through time should also be done.     

Irrigation water rates in Mendoza's decentralized irrigation administration

The cost of irrigation water to the farmers in Mendoza Province consists of three components; canal cleaning by the farmer, a water charge to their Users Association (UA) and a water charge to the provincial Irrigation Department (DGI). The total cost of irrigation water shows large differences when the area of the UA is taken into consideration: farmers in smaller associations pay considerably more than those in large units. This is the case for all three groups of costs. The annual budgets of 31 UA's were analyzed with respect to 19 budget items prescribed by DGI. Several of these items contain a low percentage of the total budget. Further, they make participation of users during the annual meeting in which the budget is discussed and approved unnecessary difficult. We recommend to reduce the number of budget items to 7. Because of low collection levels (average 64%) the UA's spend a major part of their income on recurrent costs like salaries. As a result little is spent on maintenance and improvement of the system, creating dissatisfaction with the paying water users. Thus. a vicious circle needs to be broken about the deterioration of the system, dissatisfaction of users, less participation in the running of the Association and further deterioration. Recent experience shows that the discontinuation of flow to non-paying users in combination with improved water delivery services by the UA breaks the circle.     

An Integration of Water Physicochemistry,Algal Bioassays,Phytoplankton, and Zooplankton for Ecotoxicological Assessment in a Highly Polluted Lowland River

Results of different approaches potentially useful for the evaluation of water ambient quality were analysed and compared in a small temperate lowland river with mixed diffuse and multiple-point source pollution. The Reconquista River (Buenos Aires Province, Argentina), one of the most polluted watercourses of Latin America, receives agrochemicals as well as domestic and industrial (mostly untreated) effluents. Physical and chemical water variables were determined; unispecies algal bioassays (with Chlorella pyrenoidosa and Scenedesmus acutus) were carried out in laboratory; and density and structure of phyto- and zooplankton were analysed at three sites in four dates (representing a range of likely conditions in the river). A general scheme of association among plankton, bioassays and physical/chemical variables was elaborated, that helped to infer possible control factors in this multi-stressed system. Some empirical methods, but mainly mathematical ones including multivariate techniques (as PCA, cluster analysis), were applied for evaluation of samples. A preliminary selection of indices and attributes as potential indicators of the water river quality was made, and then applied for assay a tentative integrative ordination of samples. The relative best water quality was recorded when-where dissolved oxygen concentration, algal diversity and planktonic crustacean density were higher. The worst water quality corresponded to the lack of cladocerans and lowest crustacean density, and higher: organic and industrial pollution, major nutrients (ammonium and orthophosphates), BOD, hardness, conductivity, algal biomass in bioassays, phytoplankton density (>10 000 ind. mL^-1), dominance of a single algal species (>90%), and rotifer proportion in zooplankton (>85%).     

Dynamics of humic fractions and microbial activity under no-tillage or reduced tillage,as compared with native pasture (Pampa Argentina)

Humic fractions, arginine ammonification and soil respiration were monitored in spring, summer and autumn 1999 in natural pasture soil and in no-tillage or reduced-tillage soil under maize. The Typic Argiudoll soils, typical of the Argentine rolling pampa, can be structurally unstable, particularly when conventionally tilled, a form of soil management affecting the humification process. The no-tillage soil had a lower content of fulvic acids than the reduced-tillage soil in spring and summer, probably because the humification process was favored by residue management in no-tillage soil, with a significant increase in the most stable fraction. Both arginine ammonification and CO₂ were significantly correlated with the humic acids and humin contents. No significant correlation was found with fulvic acids,probably due to the lability and high variability of this fraction. A high correlation was found between arginine ammonification and CO₂. The highest index values were generally observed in natural pasture soil, whereas no-tillage soils showed a higher index value than reduced-tillage soils throughout, confirming the hypothesis that humification is more intense in the presence of organic residues.