Characterization of Plant Alcohol Dehydrogenase

The final activity of the alcohol dehydrogenase (E.C.1.1.1.1, abbreviated ADH) from germinating pea, isolated by fractionating with ammonium sulphate, chromatography on DEAE cellulose and gel filtration, was 80,000, from bean 25,000 and from lentil 13,500 units per mg protein. Molecular weights of the ADHs are close to each other: pea and bean ADH 60,000, lentil ADH 70,000. The K_m values are mutually similar with three enzymes, i.e. of the order of 10⁻⁴M for NAD and 10⁻²M for ethanol. The pH optima lie in the alkaline region. These enzymes catalyse oxidation of a number of monovalent alcohols. At temperatures above 60°C the enzymes are thermally unstable. Stability is enhanced slowly by ethanol but not by NAD. Pyrazol, imidazol and pyridine inhibit plant ADH similarly to the enzyme from horse liver. There is a similarity between plant alcohol dehydrogenases and animal and yeast enzymes.     

METHODS OF ASSESSING THE SPORICIDAL EFFICIENCY OF AN ULTRA-HIGH-TEMPERATURE MILK STERILIZING PLANT I. EXPERIMENTS WITH SUSPENSIONS OF SPORES IN WATER

SUMMARY: A method of assessing the sporicidal efficiency of a UHT milk sterilizing plant operating on water is described. Water heavily contaminated with spores of a strain of Bacillus subtilis was filtered, after treatment in the plant, through membrane filters and the surviving spores estimated by incubation of the membranes in nutrient agar. With this plant a temperature of c . 135° caused a 99·99999% kill of B. subtilis spores. Confirmation of the lethal effects of temperatures above 135° was obtained by passing treated water into 10 gal churns containing sterile concentrated nutrient broth and incubating the churns.     

The Influence of Leaf Position and Defoliation on the Assimilation and Translocation of Carbon in White Clover (Trifolium repens L.) 1. Carbon Distribution Patterns

The assimilation of carbon (C) by, and distribution of ¹⁴C from,leaves at each end of an unbroken sequence of ten mature leaveson the main stolon of clonal plants of white clover (Trifoliumrepens L.) were measured to identify intra-plant factors determiningthe direction of C movement from leaves. Leaves at two intermediatepositions were also measured. Localized movement of ¹⁴C to sinks at the same node as, or atthe one to two nodes immediately behind, the fed leaf accountedfor 40–50% of the total ¹⁴C exported by all measured leaves.A further 50–60% of exported ¹⁴C was therefore availablefor more-distant sinks, and the direction of translocation ofthis C was determined by the relative total strength or demand(number x size x rate of activity or growth) of sinks forwardof, or behind, the leaf in question. Thus 85% of the ¹⁴C exportedfrom the youngest measured leaf moved toward the base of thestolon, while about 60% of the ¹⁴C exported from the oldestleaf moved acropetally. Defoliating plants to leave just one mature leaf on the mainstolon (at any one of the same four positions studied in undefoliatedplants), and no leaves on branches, resulted in: (1) increasednet photosynthetic rate in all residual leaves: (2) increased%export of fixed C from one of the four leaves; (3) increasedexport to the main stolon apex from all except the eldest leaf;(4) increased export to branches from three of the four leaves;and (5) decreased export to stolon tissue and roots from allleaves, within 3 d of defoliation. These responses would seemto ensure the fastest possible replacement of lost leaf areaand, thus, restoration of homeostatic growth. The observed patternsof C assimilation and distribution in both undefoliated anddefoliated white clover plants are consistent with the generalrules of source-sink theory; the distance between sources andcompeting sinks, and relative sink strength, emerge as the mostimportant intra-plant factors governing C movement. These resultsemphasize the need to consider plant morphology, and the modularnature of plant growth, when interpreting patterns of resourceallocation in clonal plants, or plant responses to stressessuch as partial defoliation. Trifolium repens L, white clover, photosynthesis, assimilate translocation, defoliation     

GLOBALIZATION, HUMAN RIGHTS, AND THE SOCIAL DETERMINANTS OF HEALTH

Globalization, a process characterized by the growing interdependence of the world's people, impacts health systems and the social determinants of health in ways that are detrimental to health equity. In a world in which there are few countervailing normative and policy approaches to the dominant neoliberal regime underpinning globalization, the human rights paradigm constitutes a widely shared foundation for challenging globalization's effects. The substantive rights enumerated in human rights instruments include the right to the highest attainable level of physical and mental health and others that are relevant to the determinants of health. The rights stipulated in these documents impose extensive legal obligations on states that have ratified these documents and confer health entitlements on their residents. Human rights norms have also inspired civil society efforts to improve access to essential medicines and medical services, particularly for HIV/AIDS. Nevertheless, many factors reduce the potential counterweight human rights might exert, including and specifically the nature of the human rights approach, weak political commitments to promoting and protecting health rights on the part of some states and their lack of institutional and economic resources to do so. Global economic markets and the relative power of global economic institutions are also shrinking national policy space. This article reviews the potential contributions and limitations of human rights to achieving greater equity in shaping the social determinants of health.     

The benefits of male ejaculate sex peptide transfer in Drosophila melanogaster

The accessory gland protein (Acp) ejaculate molecules of male Drosophila melanogaster mediate sexual selection and sexual conflict at the molecular level. However, to date no studies have comprehensively measured the timing and magnitude of fitness benefits to males of transferring specific Acps. This is an important omission because without this information it is not possible to fully understand the strength and form of selection acting on adaptations such as Acps. Here, we measured the fitness benefits to males of ejaculate sex peptide (SP) transfer. SP is of interest because it is a candidate for mediating sexual conflict: its frequent receipt reduces female fitness. In single matings with virgin females SP is known to increase egg laying and decrease receptivity. Hence, we predicted that SP could: (i) boost a male’s absolute paternity by increasing offspring production and delaying female remating and/or (ii) boost relative paternity share. We tested these predictions using two different lines of SP‐lacking males, in both two‐mating and free‐mating assay conditions. SP transfer conferred higher absolute, but not relative, male reproductive success. In matings with virgin females, SP transfer increased mating productivity and delayed remating and hence the onset of sperm competition. In already mated females, SP transfer did not elevate absolute progeny production, but did increase intermating intervals and hence the period over which a male could gain paternity. Consistent with this, under free‐mating conditions over an extended period, we detected a ‘per‐mating’ fitness benefit for males transferring SP. These benefits are consistent with a role for SP in mediating conflict, with SP acting to maximize short‐term fitness benefits for males.     

Evolutionary transitions among dioecy,androdioecy and hermaphroditism in limnadiid clam shrimp (Branchiopoda: Spinicaudata)

Examinations of breeding system transitions have primarily concentrated on the transition from hermaphroditism to dioecy, likely because of the preponderance of this transition within flowering plants. Fewer studies have considered the reverse transition: dioecy to hermaphroditism. A fruitful approach to studying this latter transition can be sought by studying clades in which transitions between dioecy and hermaphroditism have occurred multiple times. Freshwater crustaceans in the family Limnadiidae comprise dioecious, hermaphroditic and androdioecious (males + hermaphrodites) species, and thus this family represents an excellent model system for the assessment of the evolutionary transitions between these related breeding systems. Herein we report a phylogenetic assessment of breeding system transitions within the family using a total evidence comparative approach. We find that dioecy is the ancestral breeding system for the Limnadiidae and that a minimum of two independent transitions from dioecy to hermaphroditism occurred within this family, leading to (1) a Holarctic, all‐hermaphrodite species, Limnadia lenticularis and (2) mixtures of hermaphrodites and males in the genus Eulimnadia. Both hermaphroditic derivatives are essentially females with only a small amount of energy allocated to male function. Within Eulimnadia, we find several all‐hermaphrodite populations/species that have been independently derived at least twice from androdioecious progenitors within this genus. We discuss two adaptive (based on the notion of ‘reproductive assurance’) and one nonadaptive explanations for the derivation of all‐hermaphroditism from androdioecy. We propose that L. lenticularis likely represents an all‐hermaphrodite species that was derived from an androdioecious ancestor, much like the all‐hermaphrodite populations derived from androdioecy currently observed within the Eulimnadia. Finally, we note that the proposed hypotheses for the dioecy to hermaphroditism transition are unable to explain the derivation of a fully functional, outcrossing hermaphroditic species from a dioecious progenitor.     

Identification and functional characterization of effectors in expressed sequence tags from various life cycle stages of the potato cyst nematode Globodera pallida

In this article, we describe the analysis of over 9000 expressed sequence tags (ESTs) from cDNA libraries obtained from various life cycle stages of Globodera pallida . We have identified over 50 G. pallida effectors from this dataset using bioinformatics analysis, by screening clones in order to identify secreted proteins up-regulated after the onset of parasitism and using in situ hybridization to confirm the expression in pharyngeal gland cells. A substantial gene family encoding G. pallida SPRYSEC proteins has been identified. The expression of these genes is restricted to the dorsal pharyngeal gland cell. Different members of the SPRYSEC family of proteins from G. pallida show different subcellular localization patterns in plants, with some localized to the cytoplasm and others to the nucleus and nucleolus. Differences in subcellular localization may reflect diverse functional roles for each individual protein or, more likely, variety in the compartmentalization of plant proteins targeted by the nematode. Our data are therefore consistent with the suggestion that the SPRYSEC proteins suppress host defences, as suggested previously, and that they achieve this through interaction with a range of host targets.