Phenols and flavonoids in Aleppo pine needles as bioindicators of air pollution

The aim of the present study is to assess whether certain ecophysiological responses (contents of total phenols, total proanthocyanidins, and total and simple flavonols), in the needles of Aleppo pines (Pinus halepensis Mill.) may be valid bioindicators for the assessment of the air quality. Samples were taken at five natural sites polluted by various pollutants (NO, NO2, other NOx, SO2, and O3). The results show a decrease in total phenol concentrations with levels of nitrogen oxide pollutions (significant negative correlations between the total phenol concentrations and concentrations of NO, NO2, and other NOx). Total flavonoids (total flavonols and proanthocyanidins) are useful bioindicators for ozone pollution (significant negative correlations between total proanthocyanidins and the concentrations of ozone and significant positive correlations between total flavonols and the ozone pollution). Sulfur dioxide pollution is distinguished by low concentrations in quercetin, isorhamnetin, and kaempferol (significant negative correlations between these simple flavonols and the concentrations of SO2). This work confirms the strong interest of using the phenolic compounds of Pinus halepensis as biological indicators of air quality.     

Photopigment and spectral sensitivity in the bioluminescent fish Porichthys notatus

Digitonin extracts from retinas of the marine fish Porichthys notatus, from California and Puget Sound (USA), contain a single photopigment with maximum absorbance at 498 nm. In the presence of hydroxylamine the final product of bleaching absorbs maximally at 367 nm, indicating that the photopigment is based on retinal. Spectral sensitivity measurements performed on intact eyes and eye-cup preparations in darkadapted and selectively light-adapted states yield curves which suggest that the retina of P. notatus contains at least 3 different types of receptors. In the darkadapted state, the spectral sensitivity curve has a broad peak, with a maximum between 480 and 500 nm. In the blue and red light-adapted states, in addition to depressing the sensitivity, the shape of the sensitivity curve also changes. Under these conditions new peaks appear which suggest the presence of at least two different types of cones, with sensitivity maxima in the blue and the green regions of the spectrum, respectively. Comparison of the spectral sensitivity curves with the in vivo bioluminescence emission spectrum of the fish gives an especially good correspondence and suggests that the fish is able to perceive the bioluminescence of its own species.     

Comparison of the Activity of Alcohol-Based Handrubs Against Human Noroviruses Using the Fingerpad Method and Quantitative Real-Time PCR

Noroviruses (NoV) are the most common cause of acute nonbacterial gastroenteritis in the United States, and human hands play an important role in their transmission. Little is known about the efficacy of hand hygiene agents against these highly infectious pathogens. We investigated the activity of seven commercially available hand hygiene products against human noroviruses by in vivo fingerpad tests. The in vivo activity of alcohol-based handrubs ranged from 0.10 to 3.74 log reduction and was not solely dependent on alcohol concentration. A handrub (VF481) based on 70% ethanol and a blend of other skin care ingredients reduced Norwalk virus (NV) by 3.74 log in 15 s and provided significantly greater NV reduction than all the other products tested (P < 0.001). Furthermore, VF481 was the most effective product tested against the NoV genogroup II strains Snow Mountain virus (GII.2) and a GII.4 strain. These results demonstrate that alcohol by itself is not effective against NoV, but effective formulation of alcohol-based handrubs can achieve significant reduction of norovirus RNA on fingers.     

Tributyltin chloride disrupts aortic vascular reactivity and increases reactive oxygen species production in female rats

Environmental Science and Pollution Research - Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine...     

Heavy metal inputs evolution to an urban hypertrophic coastal lagoon, Rodrigo De Freitas Lagoon, Rio De Janeiro, Brazil

This work discusses the temporal variation of metal concentrations in a hypertrophic coastal lagoon located in the metropolitan area of Rio de Janeiro (Brazil). The lagoon watershed includes one of the mostly densely urbanized areas of the city but without industrial activities. Six sediment cores were collected in the lagoon between May and July 2003 and analyzed for the concentration of metals (Fe, Al, Mn, Zn, Pb, Cu, Cr, and Ni). Typical sedimentation rate was calculated as being 0.75 cm year^???1 and was uniform for at least the past 70 years. Therefore, the alterations in the dynamics of the lagoon caused by changes in its watershed were clearly indicated in sediment cores. The construction of an artificial canal to the sea and the increasing urbanization and soil use changes were the major factors affecting metal accumulation in the lagoon sediments. Metals typical of anthropogenic urban sources (Pb, Zn, and Cu) showed increasing loads following urbanization.     

Mobilization of metals and phosphorus from intact forest soil cores by dissolved inorganic carbon

Increased dissolved inorganic carbon (DIC) enhances the mobilization of metals and nutrients in soil solutions. Our objective was to investigate the mobilization of Al, Ca, Fe, and P in forest soils due to fluctuating DIC concentrations. Intact soil cores were taken from the O and B horizons at the Bear Brook Watershed in Maine (BBWM) to conduct soil column transport experiments. Solutions with DIC concentrations (～20–600 ppm) were introduced into the columns. DIC was reversibly sorbed and its migration was retarded by a factor of 1.2 to 2.1 compared to the conservative sodium bromide tracer, corresponding to a log K _D?=???0.82 to ?0.07. Elevated DIC significantly enhanced the mobilization of all Al, Fe, Ca, and P. Particulate (>0.4 μm) Al and Fe were mobilized during chemical and flow transitions, such as increasing DIC and dissolved organic carbon (DOC), and resumption of flow after draining the columns. Calcium and P were primarily in dissolved forms. Mechanisms such as ion exchange (Al, Fe, Ca), ligand- and proton-promoted dissolution (Al and Fe), and ligand exchange (P) were the likely chemical mechanisms for the mobilization of these species. One column was packed with dried and sieved B-horizon soil. The effluent from this column had DOC, Al, and Fe concentrations considerably higher than those in the intact columns, suggesting that these species were mobilized from soil’s microporous structure that was otherwise not exposed to the advective flow. Calcium and P concentrations, however, were similar to those in the intact columns, suggesting that these elements were less occluded in soil particles.     

Trends in real commodity prices: How real is real?

Testing for the existence of downward trends in real commodity prices has been the focus of several studies since the Prebisch–Singer hypothesis was formulated back in 1950. In this article, we focus on annual and monthly series of various commodity categories and consider alternative price deflators. Based on the methodology of Harvey et al. (2010), which is robust to the order of integration of the time series, we conclude that the time frequency and the price deflators play a key role when testing for the Prebisch–Singer hypothesis. For instance, at an annual frequency (1900–2003, 1900–2008), it becomes considerably more likely to support it when deflating by the unadjusted US CPI-all items than when deflating by the Manufactures Unit Value (MUV) Index or the Historical Price Index of Manufactures (HPIM). This finding is in agreement with the Svedberg and Tilton (2006) discussion on the CPI's overestimation of inflation and the measurement of the real price of copper. When dealing with monthly data (January 1957–December 2010), our results show that real prices tend not to reject the null hypothesis of a trendless series, except when deflating by the PPI-Crude Materials and, to a lesser extent, by the HPIM.     

Water deficit stress induces different monoterpene and sesquiterpene emission changes in Mediterranean species. Relationship between terpene emissions and plant water potential

The effects of water deficit stress and plant water potential (psi) on monoterpene and sesquiterpene leaf emissions from Rosmarinus officinalis, Pinus halepensis, Cistus albidus and Quercus coccifera were studied over 11 days of water withholding (from t(1) to t(11)), after substrates had achieved their field capacity (control pots: t(0)). Volatile compounds were sampled from the same twig per plant all throughout the study, using a dynamic bag enclosure system. Volatiles, collected in Tenax TA, were studied by means of GC-FID and GC-MS. Monoterpene emissions of water stressed plants (t(1)-t(11)) were either similar to those of control seedlings (R. officinalis and Q. coccifera) or higher (P. halepensis and C. albidus). By contrast, sesquiterpene emissions were strongly reduced or inhibited after four days of water withholding, particularly for R. officinalis, thus altering terpene emission composition. Despite the positive effect of water stress on leaf monoterpene emissions of P. halepensis and C. albidus, the significant correlation between these emissions and psi showed a slow decrease of these emissions over long term water deficit periods. This contrasted with the rapid decline of sesquiterpene emissions of R. officinalis according to lower values of psi. These results provide an overall picture of the different responses of monoterpene and sesquiterpene emissions to progressive water loss. They also reveal the utility of using psi for estimating some emission rates of some species according to drought conditions.     

Derivation of ozone flux-yield relationships for lettuce: a key horticultural crop

Ozone flux-response relationships were derived for lettuce, employing a multiplicative approach to model the manner in which stomatal conductance is influenced by key environmental variables, using a dataset collected during field experimentation in Crete and yield-response relationships derived from parallel open-top chamber experiments. Regional agronomic practices were adopted throughout. Computed versus measured data revealed that the derived model explained 51% (P<0.001) of the observed variation in stomatal conductance. Concentration-based indices were compared with flux-based indices. Analyses revealed a significant relationship between accumulated stomatal ozone flux and yield employing flux threshold cut-offs up to 4 nmol m(-2) s(-1). Regressions employing very low or zero flux thresholds resulted in the strongest yield-flux relationships (explaining approximately 80% (P<0.05) of the variation in the dataset).