Social Factors Influencing Russian Male Alcohol Use over the Life Course: A Qualitative Study Investigating Age Based Social Norms,Masculinity, and Workplace Context

The massive fluctuations occurring in Russian alcohol-related mortality since the mid-1980s cannot be seen outside of the context of great social and economic change. There is a dearth of qualitative studies about Russian male drinking and especially needed are those that address social processes and individual changes in drinking. Conducted as part of a longitudinal study on men’s alcohol consumption in Izhevsk, this qualitative study uses 25 semi-structured biographical interviews with men aged 33–60 years to explore life course variation in drinking. The dominant pattern was decreasing binge and frequent drinking as men reached middle age which was precipitated by family building, reductions in drinking with work colleagues, and health concerns. A minority of men described chaotic drinking histories with periods of abstinence and heavy drinking. The results highlight the importance of the blue-collar work environment for conditioning male heavy drinking in young adulthood through a variety of social, normative and structural mechanisms. Post-Soviet changes had a structural influence on the propensity for workplace drinking but the important social function of male drinking sessions remained. Bonding with workmates through heavy drinking was seen as an unavoidable and essential part of young men’s social life. With age peer pressure to drink decreased and the need to perform the role of responsible breadwinner put different behavioural demands on men. For some resisting social pressure to drink became an important site of self-determination and a mark of masculine maturity. Over the lifetime the place where masculine identity was asserted shifted from the workplace to the home, which commonly resulted in a reduction in drinking. We contribute to existing theories of Russian male drinking by showing that the performance of age-related social roles influences Russian men’s drinking patterns, drinking contexts and their attitudes. Further research should be conducted investigating drinking trajectories in Russian men.     

HDAC-mediated control of ERK- and PI3K-dependent TGF-β-induced extracellular matrix-regulating genes

Histone deacetylases (HDACs) regulate the acetylation of histones in the control of gene expression. Many non-histone proteins are also targeted for acetylation, including TGF-β signalling pathway components such as Smad2, Smad3 and Smad7. Our studies in mouse C3H10T1/2 fibroblasts suggested that a number of TGF-β-induced genes that regulate matrix turnover are selectively regulated by HDACs. Blockade of HDAC activity with trichostatin A (TSA) abrogated the induction of a disintegrin and metalloproteinase 12 (Adam12) and tissue inhibitor of metalloproteinases-1 (Timp-1) genes by TGF-β, whereas plasminogen activator inhibitor-1 (Pai-1) expression was unaffected. Analysis of the activation of cell signalling pathways demonstrated that TGF-β induced robust ERK and PI3K activation with delayed kinetics compared to the phosphorylation of Smads. The TGF-β induction of Adam12 and Timp-1 was dependent on such non-Smad signalling pathways and, importantly, HDAC inhibitors completely blocked their activation without affecting Smad signalling. Analysis of TGF-β-induced Adam12 and Timp-1 expression and ERK/PI3K signalling in the presence of semi-selective HDAC inhibitors valproic acid, MS-275 and apicidin implicated a role for class I HDACs. Furthermore, depletion of HDAC3 by RNA interference significantly down-regulated TGF-β-induced Adam12 and Timp-1 expression without modulating Pai-1 expression. Correlating with the effect of HDAC inhibitors, depletion of HDAC3 also blocked the activation of ERK and PI3K by TGF-β. Collectively, these data confirm that HDACs, and in particular HDAC3, are required for activation of the ERK and PI3K signalling pathways by TGF-β and for the subsequent gene induction dependent on these signalling pathways.     

Self-assembly of rationally designed peptides under two-dimensional confinement

The rational design of interfacially confined biomolecules offers a unique opportunity to explore the cooperative relationship among self-assembly, nucleation, and growth processes. This article highlights the role of electrostatics in the self-assembly of β-sheet-forming peptides at the air-water interface. We characterize the phase behavior of a periodically sequenced sheet-forming peptide by using Langmuir techniques, Brewster angle microscopy, attenuated total reflection Fourier transform infrared spectroscopy, and circular dichroism spectroscopy. We find that peptides with an alternating binary sequence transition at high pressures from discrete circular domains to fibrous domains. The qualitative behavior is independent of surface pressure but dependent on molecular areas. In addition, thermodynamic models are employed to specifically quantify differences in electrostatics by obtaining parameters for the critical aggregation area, the limiting molecular area, and the dimensionless ratio of line tension/dipole density. Using these parameters, we are able to relate localized charge distribution to phase transitions, which will allow us to apply these molecules to examine how the dynamics of self-assembly can be directly coupled to the formation of composite nanostructures in biology.     

Cycloartane glycosides from leaves of Oxyanthus pallidus

From the MeOH extract of leaves of Oxyanthus pallidus, three cycloartane glycosides, named pallidiosides A-C, were isolated together with two known compounds, oleanolic acid and 3-O-β-D-glucopyranosyl-β-sitosterol. The structures of pallidiosides A-C were assigned on the basis of spectral studies and comparison with published literature data. The known compounds were identified by means of Co TLC and confirmed by their physical constants.     

Development of a Novel Aluminum Tolerance Phenotyping Platform Used for Comparisons of Cereal Aluminum Tolerance and Investigations into Rice Aluminum Tolerance Mechanisms

The genetic and physiological mechanisms of aluminum (Al) tolerance have been well studied in certain cereal crops, and Al tolerance genes have been identified in sorghum (Sorghum bicolor) and wheat (Triticum aestivum). Rice (Oryza sativa) has been reported to be highly Al tolerant; however, a direct comparison of rice and other cereals has not been reported, and the mechanisms of rice Al tolerance are poorly understood. To facilitate Al tolerance phenotyping in rice, a high-throughput imaging system and root quantification computer program was developed, permitting quantification of the entire root system, rather than just the longest root. Additionally, a novel hydroponic solution was developed and optimized for Al tolerance screening in rice and compared with the Yoshida''s rice solution commonly used for rice Al tolerance studies. To gain a better understanding of Al tolerance in cereals, comparisons of Al tolerance across cereal species were conducted at four Al concentrations using seven to nine genetically diverse genotypes of wheat, maize (Zea mays), sorghum, and rice. Rice was significantly more tolerant than maize, wheat, and sorghum at all Al concentrations, with the mean Al tolerance level for rice found to be 2- to 6-fold greater than that in maize, wheat, and sorghum. Physiological experiments were conducted on a genetically diverse panel of more than 20 rice genotypes spanning the range of rice Al tolerance and compared with two maize genotypes to determine if rice utilizes the well-described Al tolerance mechanism of root tip Al exclusion mediated by organic acid exudation. These results clearly demonstrate that the extremely high levels of rice Al tolerance are mediated by a novel mechanism, which is independent of root tip Al exclusion.Aluminum (Al) is the most abundant metal in the earth''s crust, constituting approximately 7% of the soil (Wolt, 1994). Al is predominately found as a key component of soil clays; however, under highly acidic soil conditions (pH < 5.0), Al³⁺ is solubilized into the soil solution and is highly phytotoxic. Al³⁺ causes a rapid inhibition of root growth that leads to a reduced and stunted root system, thus having a direct effect on the ability of a plant to acquire both water and nutrients. Approximately 30% of the world''s total land area and over 50% of potentially arable lands are acidic, with the majority (60%) found in the tropics and subtropics (von Uexkull and Mutert, 1995). Thus, acidic soils are a major limitation to crop production, particularly in the developing world.As a whole, cereal crops (Poaceae) provide an excellent model for studying Al tolerance because of their abundant genetic resources, large, active research communities, and importance to agriculture. In addition, work in one cereal species can rapidly translate into impact throughout the family. Previous research has focused on understanding the genetic and physiological mechanisms of Al tolerance in maize (Zea mays), sorghum (Sorghum bicolor), and wheat (Triticum aestivum). The most recognized physiological mechanism conferring Al tolerance in plants involves exclusion of Al from the root tip (Miyasaka et al., 1991; Delhaize and Ryan, 1995; Kochian, 1995; Kochian et al., 2004a, 2004b). The exclusion mechanism is primarily mediated by Al-activated exudation of organic acids such as malate, citrate, or oxalate from the root apex, the site of Al toxicity (Ryan et al., 1993, 2001; Ma et al., 2001). These organic acids chelate Al in the rhizosphere, reducing the concentration and toxicity of Al at the growing root tip (Ma et al., 2001). Phosphate has also been identified as a class of root exudates involved in cation chelation and therefore can be considered a potential exudate involved in Al exclusion from the root tip (Pellet et al., 1996).Al-activated malate and citrate anion efflux transporters have been cloned from wheat (ALMT1; Sasaki et al., 2004) and sorghum (SbMATE; Magalhaes et al., 2007), and root citrate efflux transporters have been implicated in Al tolerance in maize (Piñeros and Kochian, 2001; Zhang et al., 2001). Recently, a maize homolog of sorghum SbMATE was shown to be the root citrate efflux transporter that plays a role in maize Al tolerance (Maron et al., 2010). Although organic acids have been shown to play a major role in Al tolerance in these species, another exclusion mechanism has been identified in an Arabidopsis (Arabidopsis thaliana) mutant, where a root-mediated increase in rhizosphere pH lowers the Al³⁺ activity and thus participates in Al exclusion from the root apex (Degenhardt et al., 1998). Furthermore, there is clear evidence that tolerance in maize cannot be fully explained by organic acid release (Piñeros et al., 2005). These types of findings strongly suggest that multiple Al tolerance mechanisms exist in plants.Rice (Oryza sativa) has been reported to be the most Al-tolerant cereal crop under field conditions, capable of withstanding significantly higher concentrations of Al than other major cereals (Foy, 1988). Despite this fact, very little is known about the physiological mechanisms of Al tolerance in rice. Two independent studies have identified increased Al accumulation in the root apex in susceptible compared with Al-tolerant rice varieties, but no differences were observed in organic acid exudation or rhizosphere pH (Ma et al., 2002; Yang et al., 2008). These studies suggest that rice may contain novel physiological and/or genetic mechanisms that confer significantly higher levels of Al tolerance than those found in other cereals. A more thorough analysis is required to clarify the mechanism of Al tolerance in rice.Cultivated rice is characterized by deep genetic divergence between the two major varietal groups: Indica and Japonica (Dally and Second, 1990; Garris et al., 2005; Hu et al., 2006; Londo et al., 2006). Extensive selection pressure over the last 10,000 years has resulted in the formation of five genetically distinct subpopulations: indica and aus within the Indica varietal group, and temperate japonica, tropical japonica, and aromatic/groupV within the Japonica varietal group (Garris et al., 2005; Caicedo et al., 2007; K. Zhao and S. McCouch, personal communication). (Note: When referring to varietal groups, the first letter will be capitalized, while lowercase letters will be used to refer to the subpopulation groups.) Subpopulation differences in trait performance are often significant, particularly with respect to biotic and abiotic stress (Champoux et al., 1995; Lilley et al., 1996; Garris et al. 2003; Xu et al., 2009). This can lead to confusion because trait or performance differences may be confounded with subpopulation structure, leading to false positives (type 1 error; Devlin and Roeder, 1999; Pritchard and Donnelly, 2001; Yu et al., 2006; Zhao et al., 2007). Therefore, it is important to consider the subpopulation origin of genotypes being compared when studying the genetics and physiology of Al tolerance in rice.Al tolerance screening is typically conducted by comparing root growth of seedlings grown in hydroponic solutions, with and without Al (Piñeros and Kochian, 2001; Magalhaes et al., 2004; Sasaki et al., 2004). Sorghum and maize are often screened for Al tolerance in Magnavaca''s nutrient solution (Piñeros and Kochian, 2001; Magalhaes et al., 2004; Piñeros et al., 2005), while rice seedlings are typically grown in Yoshida''s solution (Yoshida et al., 1976). Furthermore, Al concentrations used to screen for Al tolerance in maize (222 μm), sorghum (148 μm), and wheat (100 μm) are significantly lower than those used for screening Al tolerance in rice (1,112–1,482 μm; Wu et al., 2000; Nguyen et al., 2001, 2002, 2003). These differences in chemical composition of the nutrient solutions make it difficult to directly compare plant response to Al across these cereals. In rice, the high Al concentrations required to observe significant differences in root growth between susceptible and resistant varieties also complicate Al tolerance screening due to the precipitation of Al along with other elements. The result is that control (−Al) and treatment (+Al) solutions may differ with regard to essential mineral nutrients that react with Al, leading to differences in growth not directly attributable to Al. Additionally, because the active form of Al that is toxic to root growth is Al³⁺, any Al that precipitates out of solution has no effect on root growth (Kochian et al., 2004a). In a hydroponic solution, Al may be found in one of four forms: (1) as free Al³⁺, where it actively inhibits root growth; (2) precipitated with other elements and essentially unavailable to inhibit plant growth; (3) different hydroxyl monomers of Al, which are not believed to be toxic to roots (Parker et al., 1988); or (4) complexed with other elements in an equilibrium between its active and inactive states. The degree to which Al inhibits root growth is primarily dependent upon the activity of free Al³⁺ in solution (Kochian et al., 2004a).The objectives of this study were to (1) develop and optimize a suitable nutrient solution and high-throughput Al tolerance screening method for rice; (2) quantify and compare differences in Al tolerance between maize, sorghum, wheat, and rice; and (3) use the developed screening methods to determine if rice utilizes the organic acid-mediated Al exclusion mechanism that is observed in maize, sorghum, and wheat.     

GEOCHEM-EZ: a chemical speciation program with greater power and flexibility

GEOCHEM-EZ is a multi-functional chemical speciation program, designed to replace GEOCHEM-PC, which can only be used on DOS consoles. Chemical speciation programs, such as GEOCHEM and GEOCHEM-PC, have been excellent tools for scientists designing appropriate solutions for their experiments. GEOCHEM-PC is widely used in plant nutrition and soil and environmental chemistry research to perform equilibrium speciation computations, allowing the user to estimate solution ion activities and to consider simple complexes and solid phases. As helpful as GEOCHEM-PC has been to scientists, the consensus was that the program was not very user friendly, was difficult to learn and to troubleshoot, and suffered from several functional weaknesses. To enhance the usability and to address the problems found in GEOCHEM-PC, we upgraded the program with a Java graphical interface, added Help files, and improved its power and function, allowing it to run on any computer that supports Windows XP, Vista or Windows 7.     

Tigers eating tigers: evidence of intraguild predation operating in an assemblage of tiger beetles

1. Co‐occurrence of closely related predators in a prey‐limited habitat appears to contradict the principle of competitive exclusion, however it may be explained through indirect effects, niche shifts, and intraguild predation. 2. The interactions between sympatric tiger beetle Cicindela species were examined. Cicindela circumpicta is the largest of three species (C. circumpicta, C. togata, C. fulgida) found in saline habitats throughout central North America. The temporal occurrence of these species overlaps, as does their spatial occurrence on exposed salt flats of saline marshes. During field observations, exoskeletal remains of C. togata were found at the study site in Nebraska, U.S.A. 3. In laboratory trials, male C. circumpicta ate C. togata in 38% of trials and female C. circumpicta ate C. togata in 50% of trials (n = 24). 4. In the field, potential prey, consisting mainly of small flies, was found mostly in shaded conditions but tiger beetles differed significantly in shade use, with C. circumpicta spending 70% of the time in the shade compared with ≈ 20% for C. togata. Differential habitat use was not explained by maximum temperature tolerances, which did not differ between the species. 5. Laboratory trials established that both tiger beetle species consumed small prey (apterous Drosophila) but C. togata was more efficient at capturing winged Drosophila. 6. Foraging efficiency, as measured by the time taken for a C. togata to capture three prey items, decreased significantly in the presence of other tiger beetles, especially C. circumpicta. 7. These results are an indication that intraguild predation and induced changes in foraging behaviour operate in the ecology of adult tiger beetles.     

Production of dehydroamino acid-containing peptides by Lactococcus lactis

Nisin is a pentacyclic peptide antibiotic produced by some Lactococcus lactis strains. Nisin contains dehydroresidues and thioether rings that are posttranslationally introduced by a membrane-associated enzyme complex, composed of a serine and threonine dehydratase NisB and the cyclase NisC. In addition, the transporter NisT is necessary for export of the modified peptide. We studied the potential of L. lactis expressing NisB and NisT to produce peptides whose serines and threonines are dehydrated. L. lactis containing the nisBT genes and a plasmid coding for a specific leader peptide fusion construct efficiently produced peptides with a series of non-naturally occurring multiple flanking dehydrobutyrines. We demonstrated NisB-mediated dehydration of serines and threonines in a C-terminal nisin(1-14) extension of nisin, which implies that also residues more distant from the leader peptide than those occurring in prenisin or any other lantibiotic can be modified. Furthermore, the feasibility and efficiency of generating a library of peptides containing dehydroresidues were demonstrated. In view of the particular shape and reactivity of dehydroamino acids, such a library provides a novel source for screening for peptides with desired biological and physicochemical properties.     

Preharvest application of exogenous abscisic acid (ABA) or an ABA analogue does not affect endogenous ABA concentration of onion bulbs

Bulb abscisic acid (ABA) concentration has been shown to decrease in stored onions, and onset of sprouting to occur at minimal ABA concentration. It was postulated that increasing prestorage bulb ABA concentration could increase storage life. Analogues of ABA that enhance biological activity and resist degradation are available and are becoming commercially viable. Exogenous ABA and an ABA analogue (8′-methylene ABA methyl ester; PBI-365) were applied separately as preharvest foliar sprays to six onion cultivars with varying storage potential. Quality indicators including pyruvate, total soluble solids and firmness were determined at regular intervals during storage. Neither ABA treatment increased endogenous bulb ABA concentration. Bulb ABA concentration decreased during storage and the onset of sprouting occurred at a minimal ABA concentration (ca. 50–120 ng g⁻¹ DW). This was followed by an increase in ABA concentration as sprout growth continued. No straightforward relationship between ABA and carbohydrate metabolism could be determined.     

Response of nitrogen dynamics in semi-natural and agricultural grassland soils to experimental variation in tide and salinity

In the framework of rehabilitation efforts to enhance the ecological value of closed-off estuaries, we studied the effects of restoring a tidal movement and seawater incursion on soil nitrogen conversion rates and vegetation response of semi-natural and agricultural grasslands in an outdoor mesocosm experiment. Intact soil monoliths including vegetation were collected in June 2004 on two locations on the shores of the Haringvliet lagoon in the south-western part of the Netherlands, which used to be a well-developed estuary before closure in 1970. For more than 1 year, soil monoliths were continuously subjected to a full-factorial combination of tidal treatment [stagnant/tidal (0.20 m amplitude)] and water type [(freshwater, oligohaline (salinity = 3)]. Soil, soil moisture and water nitrogen concentrations were monitored for a year, as well as vegetation response and nitrogen conversion rates in the soil. As expected, nitrogen mineralization rates were enhanced by the tidal treatment in comparison with the stagnant treatment. Denitrification rates however, were much less affected by tide and were even lower in the tidal treatments after 3 months in the agricultural grassland soils, implying that in general, soils were more oxic in the tidal treatments. Oligohaline treatments had virtually no effect on soil nitrogen conversion rates compared to freshwater treatments. Vegetation performance, however, was lower under saline conditions, especially in the semi-natural grassland. No further significant differences in response to the tidal and oligohaline treatments were found between the two soils although they differed strongly in soil characteristics. We conclude that if the rehabilitation measures in the former Haringvliet estuary are carried out as planned, drastic changes in soil nitrogen processes and vegetation composition will not occur.