Identification of 16-hydroxyoxohexadecanoic acid monomers in plant cutins

The structure of a new hydroxyketo fatty acid which occurs as a major monomer of Citrus limon fruit cutin has been determined by IR, NMR and MS. The monomer was shown to be a mixture of positional isomers of 16-hydroxyoxohexadecanoic acid with the 10-oxo isomer predominating. Substantial amounts of the 9-oxo isomer were present together with smaller quantities of the 8- and 7-isomers. The same compounds were also found to be important constituents of the fruit cutins of Physalis peruviana and Ribes nigrum.     

Stable isotopes in leaf water of terrestrial plants

Leaf water contains naturally occurring stable isotopes of oxygen and hydrogen in abundances that vary spatially and temporally. When sufficiently understood, these can be harnessed for a wide range of applications. Here, we review the current state of knowledge of stable isotope enrichment of leaf water, and its relevance for isotopic signals incorporated into plant organic matter and atmospheric gases. Models describing evaporative enrichment of leaf water have become increasingly complex over time, reflecting enhanced spatial and temporal resolution. We recommend that practitioners choose a model with a level of complexity suited to their application, and provide guidance. At the same time, there exists some lingering uncertainty about the biophysical processes relevant to patterns of isotopic enrichment in leaf water. An important goal for future research is to link observed variations in isotopic composition to specific anatomical and physiological features of leaves that reflect differences in hydraulic design. New measurement techniques are developing rapidly, enabling determinations of both transpired and leaf water δ¹⁸O and δ²H to be made more easily and at higher temporal resolution than previously possible. We expect these technological advances to spur new developments in our understanding of patterns of stable isotope fractionation in leaf water.     

A locus for isolated cleft palate, located on human chromosome 2q32.

We present evidence for the existence of a novel chromosome 2q32 locus involved in the pathogenesis of isolated cleft palate. We have studied two unrelated patients with strikingly similar clinical features, in whom there are apparently balanced, de novo cytogenetic rearrangements involving the same region of chromosome 2q. Both children have cleft palate, facial dysmorphism, and mild learning disability. Their karyotypes were originally reported as 46, XX, t(2;7)(q33;p21) and 46, XX, t(2;11)(q33;p14). However, our molecular cytogenetic analyses localize both translocation breakpoints to a small region between markers D2S311 and D2S116. This suggests that the true location of these breakpoints is 2q32 rather than 2q33. To obtain independent support for the existence of a cleft-palate locus in 2q32, we performed a detailed statistical analysis for all cases in the human cytogenetics database of nonmosaic, single, contiguous autosomal deletions associated with orofacial clefting. This revealed 2q32 to be one of only three chromosomal regions in which haploinsufficiency is significantly associated with isolated cleft palate. In combination, our data provide strong evidence for the location at 2q32 of a gene that is critical to the development of the secondary palate. The close proximity of these two translocation breakpoints should also allow rapid progress toward the positional cloning of this cleft-palate gene.     

The trilobite generaEocryphops andPlagiolaria (Phacopidae)

Eocryphops andPlagiolaria are revised and a new species,E. albertii, is described from the Eifelian of Morocco.“Trimerocephalus” cyclophthalmus Walther, 1907, a species long assigned toEocryphops, is regarded as a junior subjective synonym of the type species ofPlagiolaria, Pl, plagiophthalma. Eocryphops originated in the evolutionary lineage leading toPhacops (s.str.), whereasPlagiolaria was probably derived fromLochkovella. Although they have been linked with the Late Devonian group of small-eyed and blind phacopids includingCryphops and its relatives. neitherEocryphops norPlagiolaria is ancestral to these forms. Confirmed occurrences ofEocryphops andPlagiolaria are from regions that were situated on the North Gondwana margin or on plates associated with this margin.     

Evaluation of an FRDA–EGFP genomic reporter assay in transgenic mice

Friedreich ataxia is an autosomal recessive neurodegenerative disorder caused by a GAA trinucleotide expansion in the first intron of the Friedreich ataxia gene (FRDA) that causes reduced synthesis of frataxin, a mitochondrial protein likely to be involved in biosynthesis of iron–sulfur clusters. This leads to increased oxidative stress, progressive loss of large sensory neurons, and hypertrophic cardiomyopathy. To elucidate the mechanisms regulating FRDA expression and to develop an in vivo assay for agents that might upregulate FRDA expression in a therapeutically relevant manner, we have generated transgenic mice with a BAC genomic reporter construct consisting of an in-frame fusion between FRDA and the gene coding for enhanced green fluorescent protein (EGFP). Production of full-length frataxin–EGFP fusion protein was demonstrated by immunoblotting. EGFP expression was observed as early as day E3.5 of development. Most tissues of adult transgenic mice were fluorescent. The level of FRDA–EGFP expression in peripheral blood, bone marrow, and cells obtained from enzymatically disaggregated tissues was quantitated by flow cytometry. There was a twofold increase in EGFP expression in mice homozygous for the transgene when compared to hemizygous mice. These transgenic mice are a valuable tool for the examination of spatial and temporal aspects of FRDA gene expression and for the preclinical evaluation of pharmacological inducers of FRDA expression in a whole-animal model. In addition, tissues from these mice should also be valuable for stem cell transplantation studies.     

Host specificity, establishment and dispersal of the gorse thrips, Sericothrips staphylinus Haliday (Thysanoptera: Thripidae), a biological control agent for gorse, Ulex europaeus L. (Fabaceae), in Australia

Sericothrips staphylinus was released as a biological control agent for Ulex europaeus in New Zealand and Hawaii following tests on ca. 80 plant species which showed it was narrowly oligophagous. To determine the suitability of S. staphylinus for release in Australia, further host specificity tests were conducted on 38 species and cultivars of Australian plants. These tests confirmed that S. staphylinus would feed only on U. europaeus in Australia and, following formal approval, was released in Tasmania during January 2001. To develop an optimal release strategy for S. staphylinus under Australian conditions, a field trial based on an earlier New Zealand study was conducted by replicating releases of 10, 30, 90, 270 and 810 adults. Results showed that population growth, reproduction rate and the number of S. staphylinus recovered 14 months after release can be non-linear functions of release size and establishment could be achieved with as few as 10 thrips. As S. staphylinus is easily cultured ca. 250 thrips were chosen as the minimum number for release because, based on a negative binomial model, this release size produced close to the maximum population growth. Surveys in early 2007 recovered S. staphylinus from 80% of 30 sites in Tasmania, the post release period ranging from 1 to 6 years. However, densities were low (<1 thrips/cm of tip growth) with no evidence of visible plant damage. The maximum dispersal range was 180–250 m after 38 months. At all the other sites, dispersal was estimated at less than 120 m. It is possible that S. staphylinus populations are still in the lag phase of their establishment before starting to increase rapidly and disperse. However, the survey results support a recent Tasmanian study which indicated that S. staphylinus is a sedentary, latent species characterised by steady densities and low levels of damage to its host plant. Its efficacy as a biological control agent on gorse may be restricted primarily by ‘bottom up’ effects of plant quality limiting its rate of natural increase and an inability of the thrips to reach large, damaging populations under field conditions.     

The triple-120 meter shuttle test: a sport-specific test for assessing anaerobic endurance fitness in rugby league players

The aim of this study was to design a simple field test to measure the anaerobic endurance fitness of rugby league players, which is an important fitness quality in the game of rugby league. Twelve amateur football players with a mean (+/-SD) age of 21.5 years (+/-2.2) volunteered to participate in the study. The subjects completed 1 trial of the Wingate 60-second (W60) cycle test and 2 trials of the new Triple-120 meter shuttle (T120S) test. All trials were completed 4 days apart. The validity of the T120S was determined by comparing physiological responses (heart rate and blood lactate) and rating of perceived exertion to the all-out W60 cycle test. The results indicate there is a significant relationship between maximum heart rate (r = 0.63 and 0.71) for the 2 trials of the T120S and the W60 cycle test. There was no significant relationship between the 2 trials and the W60 cycle test for post 3 minute lactate (r = 0.112 and 0.101) and rating of perceived exertion (r = 0.94 and 0.161). However, the T120S test elicited greater mean values for these measures than the W60 cycle test. The results indicate that the T120S is a valid test of anaerobic endurance and represents a sports specific test of this quality that may provide useful information for players and coaches involved in the sport of rugby league.