Effects of corn deficit irrigation and soil properties on water use efficiency. A 25-year analysis of a Mediterranean environment using the STICS model

This study analyses the role of variability induced by climate and soil properties (texture and total available soil water in the root zone, TAW) on the “corn deficit irrigation–water use efficiency” relation over a 25-year period, between 1981 and 2005, in three different sites located in the South of Italy. The analysis of water use efficiency was carried out by means of three indexes: crops water use efficiency (WUE_ET and WUE_T) and irrigation water use efficiency (IWUE). These indexes can be obtained by calculating the ratio between the yield and the seasonal values of evapotranspiration (ET), transpiration (T) and irrigation volume (I). After its validation, the STICS model was retained to simulate the variables required to determine these indexes.Climatic variability affected the three indexes in different ways during the 25-year period studied. The dispersion around the mean values of the water use efficiency is 17% on average for the WUE (ET or T) indexes, whereas it could reach 54% for the IWUE index. This last index is only poorly reliable due to the high variability of rainfall during the corn growing season in the Mediterranean region.For the same level of soil water deficit, TAW led to an improvement (the case of the site with a high TAW and loam–clay soil texture), a stabilisation (the case of the site with a high TAW and clay soil texture) or a decrease (the case of the site with a poor TAW and clay soil texture) in WUE_ET and WUE_T values. For the same conditions of soil water deficit and TAW, crops water use efficiency was higher in loam textured soil than in clay soil.The results derived by analyzing three indexes (WUE_ET, WUE_T and IWUE) converge to the same conclusions on the “corn deficit irrigation–water use efficiency” relation observed at the three different sites.The hypotheses which may explain the differences observed in the different sites studied in terms of water use efficiency are discussed, with the presentation of some suggestions devised for corn irrigation practices.     

Risk assessment and surveillance for bovine spongiform encephalopathy (BSE) in Argentina

An assessment was made of the risks of bovine spongiform encephalopathy (BSE) occurring in Argentina. Most of the factors associated with the origin and development of the BSE epidemic in the UK are essentially absent. For example, Argentina's large sheep and cattle industries are based on low-cost production systems using grass. Concentrated feeds are not used for sheep, rarely for beef cattle and to a comparatively modest extent for dairy cows. Particularly important are the facts that scrapie (and BSE) has never been reported in Argentina—very small amounts of waste tissues from sheep are rendered to produce meat and bone meal (MBM)—and MBM is not used in concentrated feeds for cattle. We conclude that Argentina has an exceptionally low risk of BSE due to scrapie. There is a very small risk of BSE having been introduced via live animals imported from countries with BSE, but this could only give rise to isolated cases because MBM is not fed to cattle.

A surveillance programme has been carried out based largely on a histological examination of brains from three categories of old dairy cows: animals reported on the suspicion of having neurological disease; animals in poor condition at slaughter; healthy animals randomly selected in the abattoir. No evidence of transmissible spongiform encephalopathy was seen in several sections from each of a total of 1019 brains. We conclude that, for most practical purposes, Argentina may be considered to be free from BSE.     

Muscarinic receptor in house fly brain and its interaction with chlorobenzilate

Membranes from house fly heads were tested for the presence of mucarinic acetylcholine receptors using as a probe [³H]quinuclidinyl benzilate ([³H]QNB). Based on the presence of saturable and reversible high-affinity binding of [³H]QNB, which is inhibited by muscarinic drugs, it is suggested that these sites may be muscarinic receptors. However, these putative muscarinic receptors differ in several characteristics from the ones in mammalian brain. They have lower affinities for muscarinic drugs and lower stereoselectivity, a relatively higher affinity for the nicotinic antagonist d-tubocurarine, a lower Hill coefficient for binding of muscarinic antagonists, and a lower concentration relative to α-bungarotoxin binding sites in the same membranes. Also, unlike mammalian muscarinic receptors, they are sensitive to treatments with N-ethylmaleimide and 5,5′-dithiobis(2-nitrobenzoic acid). The effect of reduction of disulfide bonds by dithiothreitol or mercaptoethanol suggests that only the insect receptor has one or more disulfide bonds which are important to binding. On the other hand, the putative muscarinic receptors of both insect and mammalian brains have important SH group(s), whose alkylation by p-chloromercuribenzoate inhibits binding. Also, chlorobenzilate is equally effective in inhibiting [³H]QNB binding to muscarinic putative receptors of house fly and bovine brains.     

Analysis of the ozone effect on soybean in the Mediterranean region: II. The consequences on growth, yield and water use efficiency

Soybean plants were subjected, during their growing seasons, to well-watered and water-stressed conditions, and three levels of ozone concentration (zero, low and high) in open top chambers (OTCs). At the end of the soybean growing season accumulated AOT40 values were zero, 3400 and 9000 ppb h for the filtered (control), low and high levels of ozone concentration, respectively.

In well-watered conditions, an increase in ozone concentration led to a reduction in leaf area, dry matter and reproductive organs. Whereas, an increase in ozone had no effect on plants in water-stressed conditions. At a high level of ozone concentration, there was a 47% reduction in yield and a 25% reduction in WUE in comparison with the control treatment. The reduction in yield was due to a lower number of pods per plant and 1000-grain weight. Despite changes in the grain yield, the yield quality was not altered by ozone.

During the 3-year study, AOT40 was significantly correlated with the leaf area and the final above-ground dry matter. The latter was less sensitive to ozone than leaf area. These results were reliable and would be useful in soybean yield-prediction models.

Finally, the conclusion highlights the reliability of the approach adopted, which was to make observations on various time scales (hourly, daily and entire crop cycle).     

Water use efficiency of crops cultivated in the Mediterranean region: Review and analysis

Improvement of water use efficiency (WUE) of field crops in the Mediterranean region is an imperative imposed by the critical situation of water resources of the region, as well as by the demographical increment. This review reports the experimental data concerning WUE of 16 species cultivated in the region. The species include cereals, leguminous, horticultural and industrial crops. This review however underlines that WUE data of fruit trees are lacking, despite they represent one of the main productions of the Mediterranean agriculture.

In this region, the large range of WUE values observed, for the same species, can be ascribed mainly to: (i) fertilizers and water management (water regime, mineral supply and water quality); (ii) plant factors (species, variety and sensitivity of growth stage to the stress); and (iii) environmental factors (climate, atmospheric pollution, soil texture and climate change). The conclusion highlights the actual gap concerning WUE in the Mediterranean region. This gap will constitute a field of research designated to ameliorate WUE of agriculture in this region.     

A Bayesian Generalized Linear Model for Crimean–Congo Hemorrhagic Fever Incidents

Global spread of the Crimean–Congo hemorrhagic fever (CCHF) is a fatal viral infection disease found in parts of Africa, Asia, Eastern Europe and Middle East, with a fatality rate of up to 30%. A timely prediction of the prevalence of CCHF incidents is highly desirable, while CCHF incidents often exhibit nonlinearity in both temporal and spatial features. However, the modeling of discrete incidents is not trivial. Moreover, the CCHF incidents are monthly observed in a long period and take a nonlinear pattern over a region at each time point. Hence, the estimation and the data assimilation for incidents require extensive computations. In this paper, using the data augmentation with latent variables, we propose to utilize a dynamically weighted particle filter to take advantage of its population controlling feature in data assimilation. We apply our approach in an analysis of monthly CCHF incidents data collected in Turkey between 2004 and 2012. The results indicate that CCHF incidents are higher at Northern Central Turkey during summer and that some beforehand interventions to stop the propagation are recommendable. Supplementary materials accompanying this paper appear on-line.     

Circuits with light at nanoscales: optical nanocircuits inspired by metamaterials

A form of optical circuitry is overviewed in which a tapestry of subwavelength nanometer-scale metamaterial structures and nanoparticles may provide a mechanism for tailoring, patterning, and manipulating local optical electric fields and electric displacement vectors in a subwavelength domain, leading to the possibility of optical information processing at the nanometer scale. By exploiting the optical properties of metamaterials, these nanoparticles may play the role of "lumped" nanocircuit elements such as nanoinductors, nanocapacitors, and nanoresistors, analogous to microelectronics. I show that this concept of metamaterial-inspired nanoelectronics ("metactronics") can bring the tools and mathematical machinery of the circuit theory into optics, may link the fields of optics, electronics, plasmonics, and metamaterials, and may provide road maps to future innovations in nanoscale optical devices, components, and more intricate nanoscale metamaterials.     

The Effects of Estrogen Receptors' Antagonist on Brain Edema,Intracranial Pressure and Neurological Outcomes after Traumatic Brain Injury in Rat

Background:

In previous studies, the neuroprotective effect of 17β-estradiol in diffuse traumatic brain injury has been shown. This study used ICI 182,780, a non-selective estrogen receptor antagonist, to test the hypothesis that the neuroprotective effect of 17β-estradiol in traumatic brain injury is mediated by the estrogen receptors.

Methods:

The ovariectomized rats were divided into eight groups. Brain injury was induced by Marmarou’s method. Estrogen was injected 30 minutes after traumatic brain injury, and ICI 182,780 was injected before traumatic brain injury and also before estrogen treatment. In one group only ICI 182,780 was injected. The brain water content and Evans blue dye content were measured 24 and 5 hours after traumatic brain injury, respectively. The neurologic outcomes and intracranial pressure were assessed before, 4, and 24 hours after traumatic brain injury.

Results:

Brain water content and Evans blue content were less in estrogen-treated group comparison to vehicle group. ICI 182,780 eliminated the effects of estrogen on brain edema and brain blood barrier permeability. Intracranial pressure was increased significantly after trauma, and estrogen decreased intracranial pressure at 4 and 24 hours after traumatic brain injury in comparison to vehicle. This inhibitory effect was also eliminated by treatment with ICI182,780. ICI 182,780 also inhibited the estrogen induced increase in neurologic outcomes following traumatic brain injury. However, the use of ICI 182,780 alone had no neuroprotective effect after traumatic brain injury.

Conclusion:

The results suggest that classical estrogen receptors have probably a role in the neuroprotective function of estrogen following traumatic brain injury.Key Words: Estrogens, Intracranial pressure (ICP), Brain edema     

Tolerance of spring barley (Hordeum vulgare L.), oats (Avena sativa L.) and wheat (Triticum aestivum L.) to saflufenacil

Saflufenacil is a new herbicide being developed by BASF for pre-emergence application for broadleaved weed control in maize and other crops. Three field studies were conducted in Ontario, Canada over a 2-year period (2006 and 2007) to evaluate the tolerance of spring cereals (barley, oats, and wheat) to pre-emergence and post-emergence applications of saflufenacil at 50 and 100 g ai ha⁻¹. Saflufenacil pre-emergence caused minimal visible injury (1% or less) at 3, 7, 14 and 28 days after emergence and had no adverse effect on plant height or yield of barley, oats, and wheat. Saflufenacil plus the surfactant Merge (1% v/v) applied post-emergence caused as much as 76, 60, 52 and 35% visible injury in spring cereals at 3, 7, 14 and 28 DAT, respectively. Injury with saflufenacil plus Merge applied post-emergence decreased over time and was generally greater as dose increased. Saflufenacil plus Merge applied post-emergence reduced plant height by as much as 16% and reduced yield of spring barley and wheat by 24 and 13%, respectively, but had no effect on the yield of spring oats. Based on these results, saflufenacil applied pre-emergence at the proposed dose can be safely used in spring planted barley, oats and wheat; however, the post-emergence application of saflufenacil results in unacceptable injury and yield loss. These results are consistent with the proposed pre-emergence use pattern for saflufenacil.