Reciprocating hail processes in the Alps

Attention is drawn to a basicallyinverse correlation between some adverse weather events which occur in two adjacent zones of the Alps. Since atmospheric precipitation is known to be influenced by both air and thermal pollution which are generated by urban complexes, power plants etc., and since the occurrence and effects of some forms of precipitation in two small adjacent areas are normally reasonably concomitant, the existence of this inverse interdependence appears to be of interest. The phenomenon is discussed in terms of a simple model which fits, with excellent approximation, the data available on annual losses, due to hail of the agricultural produce in the Bolzano and Trento Provinces over the years 1970–1979 incl. This model may thus also be useful in future studies of annual precipitation changes which may locally be caused by the air polluting effects of increasing industrialization and urbanization.     

Reactivity of aqueous nitrates with suspended organic substance,under ultraviolet radiation

Recent research on the photoreduction of aqueous nitrite by suspensions of some organic compounds is extended to solutions of inorganic nitrates. With analogy to our previous work, formation of ammonium in the aqueous phase is found to occur. However, the related kinetics strongly depend on several concurrent reactions of nitrite, such as its decomposition, its further reduction and its attack onto the organic substance. With further analogy to the work carried out in a nitrous medium, there also is formation of diverse organic derivatives, their yields being larger by a factor of 2 to 4 at those experimental conditions.     

Comparison of volatile concentrations in hand-squeezed juices of four different lemon varieties

Fresh juices of four Italian cultivars of lemons (Citrus limon Burm) have been analyzed by headspace solid phase microextraction coupled to gas chromatography and gas chromatography-mass spectrometry (GC-MS). The best results have been obtained with the 2 cm 50/30 microm divinylbenzene/carboxen on poly(dimethylsiloxane) fiber, using a homogenization time of 1 h at 40 degrees C and a sampling period of 30 min. A total of 35 volatile compounds have been identified by GC-MS, and their relative amounts have been calculated by adding internal standard to the samples. Differences in composition of lemon juices volatile components have been observed. Verdello Siracusano lemon juice has the highest amount of volatile compounds (50.28 mg/L), followed by Interdonato (8.39 mg/L), Primo Fiore Capo d'Orlando (5.75 mg/L), and Femminello Siracusano (2.62 mg/L) juices. Volatile compounds mainly consist of mono- and sesquiterpene hydrocarbons and oxygenated molecules (aldheydes, monoterpene alcohols, and monoterpene esters). Headspace solid phase microextraction coupled to a gas chromatograph equipped with a specific sulfur detector, a sulfur chemiluminescence detector, let us detect and quantify dimethyl sulfide compound at the microgram/liter level in lemon juices.     

Iron and zinc absorption from two bean (Phaseolus vulgaris L.) genotypes in young women

Extrinsic and intrinsic iron and zinc labels were used to test iron and zinc absorption from two bean (Phaseolus vulgaris) genotypes, containing normal (common beans, CB) or higher (HFeZnB) iron and zinc concentrations, fed in single meals to young women with low iron reserves. The women were divided into two groups, with one receiving a CB test meal (n = 12) and the other, an HFeZnB test meal (n = 11). The beans were intrinsically labeled hydroponically with (55)Fe (CB and HFeZnB) and with (70)Zn (HFeZnB). Concentrations of zinc and iron were 98 and 65% higher, respectively, in HFeZnB as compared to CB, but phytic acid contents were similar. Extrinsic labels were (59)Fe (CB and HFeZnB), (67)Zn (CB), and (68)Zn (HFeZnB). Iron and zinc percent absorption levels were calculated from radio-iron activity in red blood cells and from urinary excretion of zinc isotopes. Intrinsic and extrinsic iron absorption measures were highly correlated (R (2) = 0.986) (average extrinsic/intrinsic ratio was 1.00). Iron absorption was low (geometric mean < 2%) in both bean types, and total iron absorbed was not different between types. Intrinsic zinc absorption from the HFeZn beans was higher than extrinsic absorption (15.2% vs 13.4%, p < 0.05) (average extrinsic/intrinsic was 0.90). The correlation between intrinsic and extrinsic zinc measures was not as high as that for iron (R (2) = 0.719). Percent zinc absorption levels were similar in both bean types, but total extrinsic zinc absorbed was 90% higher (p < 0.05) from the HFeZnB meal. Thus, the less expensive and time-consuming extrinsic labeling may be used to screen various varieties of beans for iron bioavailability in humans, but it underestimates zinc absorption by approximately 10%. Selective breeding for high-zinc bean genotypes may improve zinc status. However, high-iron genotypes appear to have little effect on iron status when fed alone in single meals to women with low iron reserves.     

Photoreactivity of aqueous anionic NO x − With hydrocarbons

Suspensions of N-heptane, benzene and terpin hydrate in aqueous solutions of sodium nitrate are photolyzed under sunlight at an unpolluted mountain site. Rates of nitrite and ammonium formation in the aqueous phase are found to follow patterns very similar to those previously obtained in the laboratory using artificial UV of comparable intensities and the same experimental assembly. Yields of both nitrite and ammonium formed with time are also found to be within ranges of magnitude expected on the basis of that laboratory experimentation.     

On the photolytic separation of halogens from sea water concentrates

A review of recent work on the UV photolysis of nitrate-bearing material and NO_χ is carried out and a laboratory investigation is made of rates of halogen separation from concentrated sea water by the action of UV radiation. Effects of pH, concentration, light intensity, NO ₃ ^? additive and temperature are evaluated in terms of broad trends on the process studied at a reduced pressure in an air flow. Rates of release, of NO_χ and halogens from the liquid interphase photolyzed, are found to depend directly on the nitrate present, and exponentially on the concentration of sea water, light intensity and acidity. Those rates are also found to be inhibited by temperature. The process of halogen and NO_χ release is believed to be triggered by the formation of transient pernitrite intermediate oxidants and is thought to be of importance in understanding both, some of the natural oxidative reactions which occur in the atmosphere, and of the processes which lead to the formation of hygroscopic Aitken nuclei from those released gases. An added point of interest consists in the possibility of halogenation and/or nitration of organic substance present in nitrate-bearing marine aerosol, and of a progress towards the explanation of differences in the Cl:Na ratio between this aerosol and sea water.     

Estimation of basket trap selectivity for changeable nassa (Nassarius mutabilis) in the Adriatic Sea

Size selectivity of basket traps for changeable nassa (Nassarius mutabilis) was estimated through comparative fishing trials with traps varying in mesh size and net colour. Selectivity curves of two commercial (19 mm white twine and 19 mm black twine) and three experimental (23, 26 and 28 mm white twine) traps were estimated using SELECT method. In addition, theoretical size-selectivity curves were calculated from morphometric data using a simplified version of Sechin method.Differing from the opinion of fishermen, N. mutabilis did not show any preference for dark coloured twine. Retention curves estimated with SELECT method had a very sharp selectivity and well fitted catch data in all cases. Theoretical size-selectivity curves were very close to size-selectivity curves obtained from experimental data. The two types of curve were very similar in shape, although the theoretical ones were shifted towards larger size classes and showed a slightly steeper slope than SELECT curves. The mesh size commonly used by fishermen is not adequate for rationally exploiting the resource, as catches mainly included undersized specimens, whilst the 23 and 26 mm mesh sizes would represent a good compromise between reduced occurrence of undersized individuals and satisfactory yields of commercial product.     

Simultaneous quantification of vitamin E and vitamin E metabolites in equine plasma and serum using LC-MS/MS

Vitamin E deficiencies can impact normal growth and development in humans and animals, and assessment of circulating levels of vitamin E and its metabolites may be an important endpoint for evaluation. Development of a sensitive method to detect and quantify low concentrations of vitamin E and metabolites in biological specimens allows for a proper diagnosis for patients and animals that are deficient. We developed a method to simultaneously extract, detect, and quantify the vitamin E compounds alpha-tocopherol (α-TP), gamma-tocopherol (γ-TP), alpha-tocotrienol (α-TT), and gamma-tocotrienol (γ-TT), and the corresponding metabolites formed after β-oxidation of α-TP and γ-TP, alpha-carboxymethylbutyl hydroxychroman (α-CMBHC) and alpha- or gamma-carboxyethyl hydroxychroman (α- or γ-CEHC), respectively, from equine plasma and serum. Quantification was achieved through liquid chromatography–tandem mass spectrometry. We applied a 96-well high-throughput format using a Phenomenex Phree plate to analyze plasma and serum. Compounds were separated by using a Waters ACQUITY UPLC BEH C18 column with a reverse-phase gradient. The limits of detection for the metabolites and vitamin E compounds were 8–330 pg/mL. To validate the method, intra-day and inter-day accuracy and precision were evaluated along with limits of detection and quantification. The method was then applied to determine concentrations of these analytes in plasma and serum of horses. Alpha-TP levels were 3–6 µg/mL of matrix; the metabolites were found at much lower levels, 0.2–1.0 ng/mL of matrix.     

Glucose Uptake and Oxidative Stress in Caco-2 Cells: Health Benefits from Posidonia oceanica (L.) Delile

Posidonia oceanica (L.) Delile is an endemic Mediterranean marine plant of extreme ecological importance. Previous in vitro and in vivo studies have demonstrated the potential antidiabetic properties of P. oceanica leaf extract. Intestinal glucose transporters play a key role in glucose homeostasis and represent novel targets for the management of diabetes. In this study, the ability of a hydroalcoholic P. oceanica leaf extract (POE) to modulate intestinal glucose transporters was investigated using Caco-2 cells as a model of an intestinal barrier. The incubation of cells with POE significantly decreased glucose uptake by decreasing the GLUT2 glucose transporter levels. Moreover, POE had a positive effect on the barrier integrity by increasing the Zonulin-1 levels. A protective effect exerted by POE against oxidative stress induced by chronic exposure to high glucose concentrations or tert-butyl hydroperoxide was also demonstrated. This study highlights for the first time the effect of POE on glucose transport, intestinal barrier integrity, and its protective antioxidant effect in Caco-2 cells. These findings suggest that the P. oceanica phytocomplex may have a positive impact by preventing the intestinal cell dysfunction involved in the development of inflammation-related disease associated with oxidative stress.