Quantitative structure-activity relationship of rubiscolin analogues as delta opioid peptides using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA)

Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were carried out on a series of 38 rubiscolins as delta opioid peptides using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Quantitative information on structure-activity relationships is provided for further rational development and direction of selective synthesis. All models were carried out over a training set including 30 peptides. The best CoMFA model included electrostatic and steric fields and had a moderate Q (2) = 0.503. CoMSIA analysis surpassed the CoMFA results: the best CoMSIA model included only the hydrophobic field and had a Q (2) = 0.661. In addition, this model predicted adequately the peptides contained in the test set. Our model identified that the potency of delta opioid activity of rubiscolin analogues essentially exhibited a significant relationship with local hydrophobic and hydrophilic characteristics of amino acids at positions 3, 4, 5, and 6.     

An urban-rural comparison of the prevalence of the metabolic syndrome in Eastern China

OBJECTIVE: To assess the impact of urbanisation on the prevalence of the metabolic syndrome in Chinese adults. DESIGN: As part of a community-based cross-sectional survey conducted in 2002, a sample from rural and urban populations in East China was obtained. The metabolic syndrome is defined by the National Cholesterol Education Program Adult Treatment Panel III criteria (ATP III) and the modified ATP III, which recommended a lower waist circumference cut-off for Asians.Setting Field sites in Jiangxi and Anhui provinces and the Jing'an District of Shanghai, China. SUBJECTS: A total of 529 non-pregnant, non-lactating urban and rural adults, aged 20-64 years without diagnosed diabetes. RESULTS: Dwelling in urban areas was associated with higher dietary fat intake and slightly lower total energy intake, and with significantly lower occupational physical activity. Using the ATP III criteria, the prevalence of the metabolic syndrome was significantly higher for urban than rural men (12.7 vs. 1.7%, P < 0.001), and was similar between urban and rural women (10.1 vs. 9.7%, P = 0.17). These urban-rural differences were greatly enhanced when the modified ATP III criteria for the syndrome were used, for men (34.3 vs. 2.7%, P < 0.01) and women (24.1 vs. 11.4%, P = 0.07). The Asian waist circumference cut-offs (90 and 80 cm for men and women, respectively) had a better combination of sensitivity and specificity in identifying other metabolic disorders, which included high glucose, high blood pressure, high triglycerides and low high-density lipoprotein cholesterol, for this population.Conclusion For the Chinese population, urban dwelling was associated with higher prevalence of the metabolic syndrome, especially in men.     

Lifetime traits comparison between annual and accelerated lambing systems for dairy ewes

Two sets of data with a sum of 6318 lactations for 1391 Spanish Churra ewes, belonging to 10 flocks were used to study phenotypic, genetic and system efficiency parameters of lifetime traits in annual and accelerated lambing systems. The study included four life span traits, three productive traits and two reproductive traits. Trait averages for both milk yield and revenues from sold milk and weaned lambs were calculated per-day of lifetime, productive life and useful life. The animal model included flock and ewe birth year as fixed effects. Both effects contributed significantly to variation in most traits in the annual system while birth year was non-significant for most variables of the accelerated system. Milk production level was included in the model to analyze life span traits. It contributed significantly to variation in all life span traits in both systems. Means for productive and life span traits were significantly higher in the accelerated system compared with the annual system. The average interval between successive lambings was significantly shorter in the accelerated system, while age at first lambing was significantly lower in the annual system. Except for age at first lambing, heritability estimates were clearly lower in the case of the accelerated system (0.02 to 0.20) than in the annual system (0.08 to 0.45). Genetic correlations among traits were also lower in the case of the accelerated system. Failure to lamb three times in two consecutive years and the varying reproductive management among flocks in the accelerated system may be responsible for the differences in genetic results between the two systems. Improving reproductive performance is necessary, especially for the young high yielding ewes in the accelerated system. Management to ensure high fertility, especially among young ewes, would be of more importance than removing non-lambing ewes.     

Net changes of main ions in the soil profile of irrigated field plots in central Spain

Implementation of improved irrigation schedules in some semiarid zones improve water efficiency and can be recommended where occasional periods of heavy rainfall may remove some of the accumulated salts. We hypothesized, however, that the leaching pattern of the main ions may differ regarding their potential contribution to the total salt discharge. The experiment was conducted near Madrid in Spain on a typical Xerofluvent soil with sandy-loam texture in the first 0.5 m. For 4 years, a traditional crop rotation of corn–wheat–corn–oat (Zea mays L.–Triticum aestivum L.–Zea mays L.–Avena sativa L.) was planted and two irrigation treatments (traditional and improved) were applied only to the corn. In an experimental set-up of 24 plots, samples of the soil solutions were extracted 61 times during the experiment at soil depths of 0.4, 0.9 and 1.4 m. During the experiment, drainage volume was estimated in plots under the two irrigation schedules. Main ions in the soil solution were SO₄²⁻, Cl⁻, Ca²⁺, Na⁺ and HCO₃⁻. These solutes accounted for 88% of total salt discharge under the two irrigation treatments. Two main patterns of salt leaching were observed. For most main ions, except HCO₃⁻, the input to discharge ratio was lower than one. Also for HCO₃⁻ , the irrigation treatment did not affect the leaching pattern (higher input than discharge under the two irrigation treatments). Improved irrigation schedules can be implemented without increasing the total salt load, but attention should be paid to specific leaching patterns of individual ions.     

Silver-catalyzed C-C bond formation between methane and ethyl diazoacetate in supercritical CO₂

Even in the context of hydrocarbons' general resistance to selective functionalization, methane's volatility and strong bonds pose a particular challenge. We report here that silver complexes bearing perfluorinated indazolylborate ligands catalyze the reaction of methane (CH(4)) with ethyl diazoacetate (N(2)CHCO(2)Et) to yield ethyl propionate (CH(3)CH(2)CO(2)Et). The use of supercritical carbon dioxide (scCO(2)) as the solvent is key to the reaction's success. Although the catalyst is only sparingly soluble in CH(4)/CO(2) mixtures, optimized conditions presently result in a 19% yield of ethyl propionate (based on starting quantity of the diazoester) at 40°C over 14 hours.     

Policy schemes and targeted technologies in an extensive cereal–sheep farming system

Many commentators and experts arguethat extensive agricultural systems across theEuropean Union (EU) should be supported toreach the two main functions of the EuropeanModel of Agriculture (EMA): lively economicsystems and environmental awareness. We arguethat the main current policy instrument of theEMA, the CAP (Common Agricultural Policy),should be targeted to take advantage ofexisting regional diversity in social realitiesand agricultural structures. Community-basedresearch work has been carried out throughoutthe 1990s in the cereal–sheep farming system ofCastile-La Mancha (south-central Spain), wherea system of land-use operates in which cerealcropping and sheep farming are carried out onthe same land. Local agricultural staff andfarmers acted as collaborators in rating themain constraints and devising proposals forstructural, social, and institutional reforms.Results showed that the two social groupsinvolved (cultivators and pastoralists) haddivergent interests and unbalanced numbers forcollective action to be effective. Governmentintervention is required, but current EUagricultural policy is not accomplishing therestructuring objectives. Results of theopinion survey also support switching the EUsubsidy scheme to sheep from a per-head basisto a per-hectare basis and making grazing landmore accessible to landless shepherds. Regionalpolicy schemes should be devised that aretailored to meet the circumstances ofparticular land areas, but sensible policyschemes can only be devised after properknowledge of the structure and institutionalframework of EU agricultural systems.     

Atlantic salmon living on the edge: Smolt behaviour and survival during seaward migration in River Minho

The Atlantic salmon (Salmo salar) population of the River Minho represents the southern natural distribution edge of the species. In line with the general trend for Atlantic salmon, this population has been declining over the years and is now at a critically low level. With river connectivity compromised by a large dam just 80 km upstream the River Minho's outlet, and an expected deterioration of climatic conditions, it is urgent to increase our knowledge of this population and identify survival bottlenecks that can be addressed. In this study, we used radio and acoustic telemetry to track Atlantic salmon smolts during their migration towards the sea and record both survival rates and possible causes of mortality. The recorded survival for the tagged migrating Atlantic salmon remained below 55% in the three studied years, indicating that the in‐river loss of smolts is likely a strong constraint to this population. From the smolts to which a likely cause of mortality could be attributed (34%), most appear to have been removed from the river (25%), with two confirmed events of bird predation and one of mammal predation. Interestingly, eight tags were recorded moving back upstream, likely indicating predation by larger fish. Increasing predator populations (e.g. cormorants, Phalacrocorax carbo) and invasive predators (e.g. American mink, Neovison vison) lead to elevated predation pressure on this already strained Atlantic salmon population, and further studies quantifying their impact in more detail could prove crucial for future management considerations.     

Development of a tandem repeat-based multilocus typing system distinguishing Babesia bovis geographic isolates

Mini- and microsatellite sequences have proven to be excellent tools for the differentiation of strains and populations in several protozoan parasites due to their high variability. In the present work we have searched the genome of the tick-transmitted bovine hemoprotozoon Babesia bovis for tandem repeats (TRs) that could be useful for a multilocus typing system. Hundred and nineteen sequences were shortlisted and tested in five common B. bovis reference isolates originating from distinct geographic locations of North and South America: Texas, USA (T2Bo), Mexico (RAD and Mo7), and Santa Fe and Salta, Argentina (R1A and S2P, respectively). Satellite sequences were PCR-amplified using specific primers, separated by polyacrylamide gel electrophoresis, visualized by silver staining and sized. Fourteen TR sequences could be reliably amplified in all isolates and displayed length polymorphism. All primers used were specific for B. bovis and did not amplify genomic DNA from the bovine host or from Babesia bigemina, the principal co-infecting bovine parasite in the Americas, allowing their future use in field surveys. The 14 satellite markers identified are distributed throughout the four chromosomes of B. bovis as follows: chromosome 1 (n = 3), chromosome 2 (n = 2), chromosome 3 (n = 5), and chromosome 4 (n = 4). Within the five B. bovis isolates we identified nine satellite marker loci with two alleles, three with three alleles, one with four and another with five alleles. In comparison to Theileria parva, a bovine hemoprotozoan that pertains to the same piroplasmida order and owns a genome of similar size, the number of polymorphic TRs and the average number of alleles per TR locus seem to be significantly reduced in the B. bovis genome. Furthermore, the ratio of micro- to minisatellites in both B. bovis and T. parva is considerably lower than in other eukaryotes, as confirmed by bioinformatic analysis. The multilocus genotype of the five B. bovis isolates was assessed and the genetic distance between each other determined followed by cluster analysis based on neighbor joining. The resulting phenogram showed that B. bovis isolates segregated into three clusters according to their geographic origin. The presented marker system is suitable to explore various parameters of B. bovis populations such as genetic diversity, infection dynamics and their structure under different epidemiological situations, which are of crucial importance for improved control strategies.     

Staling of frozen partly and fully baked breads. Study of the combined effect of amylopectin recrystallization and water content on bread firmness

Partly baked (PB) and fully baked (FB) breads were frozen at −18 °C for 7, 21, 63, 92, 126 and 188 d and were analysed after its thawing (FB) or thawing and final baking (PB). The starch retrogradation, the moisture content and the firmness were measured as properties closely related to the aging of bread. The temperature of glass transition of the maximally freeze-concentrated state, T_g′, was also measured and established in (−18 ± 0.8) °C. This value cannot ensure molecular immobility in both types of bread during its frozen storage at (−18 ± 2) °C. Consequently, the rearrangements of starch component molecules, needed for its recrystallization and for the diffusion of water during frozen storage, could take place and could justify the changes observed in the bread. PB bread showed a significant decrease in firmness with frozen storage, while the firmness of the FB bread did not change significantly, although an increase when compared with the control, not frozen bread, was detected. A regression study led to the conclusion that the combined effect of starch component crystallization and water loss could explain the firming evolution and that both variables exerted an effect of similar intensity on crumb firmness.