Sexual Transmission of Somatic Embryogenesis in Dactylis glomerate*

A Dactylis glomerata L. genotype that produces somatic embryos in vitro was tested for the ability to sexually transmit the embryogenic trait. Reciprocal crosses were performed between the embryogenic and two non-embryogenic genotypes. Leaf segments from 69 F₁ plants were cultured on Schenk and Hildebrandt medium amended with 30 μM 3,6-dichloro-o-anisic acid (dicamba). Somatic embryogenesis was expressed in 39 of the F₁ plants. The embryogenic parent was female for 18 of these plants and male for the other 21. The 39:30 ratio of embryogenic: non-embryogenic fits an expected 1:1 for tetrasomic inheritance of a dominant nuclear gene.     

Are review articles a reliable source of evidence to support conservation and environmental management? A comparison with medicine

Review articles are important sources of information and often the only source of evidence used by decision makers in conservation and environmental management to assess effectiveness and impact of interventions and other actions. Recent developments in the field of medicine and public health have established ‘systematic review’ guidelines to minimise bias and explicitly document methodology, allowing replication and updating in light of further advances. The aim of this article was to assess the methodological and reporting rigour of reviews from the disciplines of conservation, ecology and environmental management (referred to as “ecological reviews”). This was achieved by comparing them to medical systematic reviews, using 27 detailed criteria well established in medicine. When compared with medical systematic reviews, ecological reviews were more likely to be prone to bias, lacking details in the methods used to search for studies, and were less likely to assess the relevance of studies, quality of the original experiments and to quantitatively synthesise the evidence. Overall, ecological reviews show lower quality and greater variation in reporting style and review methods. To address this, reviewers could use a systematic review approach and journals could provide more explicit guidelines for the preparation and production of review articles.     

Water-soluble insulin receptors from human lymphocytes

Specific insulin receptors from human lymphocytes in culture have been prepared in aqueous solution without use of detergents or related compounds. Receptors prepared in this fashion exhibit characteristics identical to those reported in intact cells.     

Aryldiones incorporating a [1,4,5]oxadiazepane ring. Part 2: chemistry and biology of the cereal herbicide pinoxaden

BACKGROUND: Pinoxaden is a new cereal herbicide that provides outstanding levels of post‐emergence activity against a broad spectrum of grass weed species for worldwide selective use in both wheat and barley. RESULTS: Factors influencing activity and tolerance to pinoxaden were in part linked to distinct structural parts of the active ingredient. Three complementary contributions that decisively impact upon the herbicidal potency against grasses were identified: a preferred 2,6‐diethyl‐4‐methyl aromatic substitution pattern, a dione area suitable for proherbicide formation and beneficial adjuvant effects. The uptake and translocation pattern of pinoxaden when coapplied with its tailored adjuvant were analysed by autoradiography, indicating extensive and rapid penetration, followed by effective distribution throughout the plant. Crop injury reduction on incorporation of the [1,4,5]oxadiazepane ring into the aryldione template was reinforced with safener technology. Comparative studies on the behaviour of pinoxaden applied either alone or in combination with the safener cloquintocet‐mexyl demonstrated that addition of the safener resulted in significant enhancement of metabolic degradation in wheat and barley, providing excellent crop tolerance and a substantial selectivity margin without adverse effects on weed control. CONCLUSION: The biological potential of pinoxaden and its active principle pinoxaden dione in terms of grass weed control and tolerance in cereals was fully exploited by inclusion of the safener cloquintocet‐mexyl in the formulation in combination with a specific and tailor‐made tank‐mix adjuvant based on methylated rape seed oil. Copyright © 2011 Society of Chemical Industry     

The 10 Australian ecosystems most vulnerable to tipping points

We identify the 10 major terrestrial and marine ecosystems in Australia most vulnerable to tipping points, in which modest environmental changes can cause disproportionately large changes in ecosystem properties. To accomplish this we independently surveyed the coauthors of this paper to produce a list of candidate ecosystems, and then refined this list during a 2-day workshop. The list includes (1) elevationally restricted mountain ecosystems, (2) tropical savannas, (3) coastal floodplains and wetlands, (4) coral reefs, (5) drier rainforests, (6) wetlands and floodplains in the Murray-Darling Basin, (7) the Mediterranean ecosystems of southwestern Australia, (8) offshore islands, (9) temperate eucalypt forests, and (10) salt marshes and mangroves. Some of these ecosystems are vulnerable to widespread phase-changes that could fundamentally alter ecosystem properties such as habitat structure, species composition, fire regimes, or carbon storage. Others appear susceptible to major changes across only part of their geographic range, whereas yet others are susceptible to a large-scale decline of key biotic components, such as small mammals or stream-dwelling amphibians. For each ecosystem we consider the intrinsic features and external drivers that render it susceptible to tipping points, and identify subtypes of the ecosystem that we deem to be especially vulnerable.     

A major Archean,gold- and crust-forming event in the Kaapvaal craton,South Africa

The 2.89- to 2.76-gigayear-old conglomerates of the Central Rand Group of South Africa host an immense concentration of gold. The gold and rounded pyrites from the conglomerates yield a rhenium-osmium isochron age of 3.03 +/- 0.02 gigayears and an initial 187Os/188Os ratio of 0.1079 +/- 0.0001. This age is older than that of the conglomerates. Thus, the gold is detrital and was not deposited by later hydrothermal fluids. This Middle Archean gold mineralization event corresponds to a period of rapid crustal growth in which much of the Kaapvaal craton was formed and is evidence for a significant noble metal flux from the mantle.     

Connected to death: the (unexpurgated) mitochondrial pathway of apoptosis

The mitochondrial pathway of apoptosis in vertebrates is dependent on the process of mitochondrial outer membrane permeabilization (MOMP), which leads to the release of proteins from the mitochondrial intermembrane space into the cytosol. "Upstairs" of this event are the Bcl-2 family proteins that regulate and mediate MOMP; "downstairs" is the activation of caspases that orchestrate the dismantling of the cell. In the Connections Map database at Science's Signal Transduction Knowledge Environment (STKE), the pathways that define the mitochondrial pathway of apotosis are illustrated, with the bulk of control occurring "upstairs" of MOMP.