Postgerminative growth and lipid catabolism in oilseeds lacking the glyoxylate cycle

The glyoxylate cycle is regarded as essential for postgerminative growth and seedling establishment in oilseed plants. We have identified two allelic Arabidopsis mutants, icl-1 and icl-2, which lack the glyoxylate cycle because of the absence of the key enzyme isocitrate lyase. These mutants demonstrate that the glyoxylate cycle is not essential for germination. Furthermore, photosynthesis can compensate for the absence of the glyoxylate cycle during postgerminative growth, and only when light intensity or day length is decreased does seedling establishment become compromised. The provision of exogenous sugars can overcome this growth deficiency. The icl mutants also demonstrate that the glyoxylate cycle is important for seedling survival and recovery after prolonged dark conditions that approximate growth in nature. Surprisingly, despite their inability to catalyze the net conversion of acetate to carbohydrate, mutant seedlings are able to break down storage lipids. Results suggest that lipids can be used as a source of carbon for respiration in germinating oilseeds and that products of fatty acid catabolism can pass from the peroxisome to the mitochondrion independently of the glyoxylate cycle. However, an additional anaplerotic source of carbon is required for lipid breakdown and seedling establishment. This source can be provided by the glyoxylate cycle or, in its absence, by exogenous sucrose or photosynthesis

Detection of Salmonella in Poultry Using Conventional Culture Methods and Polymerase Chain Reaction Technique

A study was carried out to evaluate three culture media and PCR for the detection of Salmonella spp. to improve Salmonella monitoring program. A total of 109 samples were collected from two farms. Sixty four samples were collected from farm A. These included 16 cloacal swabs collected from broilers before slaughtering, 18 intestinal swabs and 20 caecal swabs collected from broilers after evisceration, and 10 cloacal swabs collected from village chickens. Forty five samples were collected from farm B, which included 15 cloacal swabs from each of village chickens, turkeys, and guinea fowls. Samples were pre-enriched in BPW and investigated by plating them on XLT4 agar after enrichment in selenite cystine broth, BPLS agar after enrichment in Rappaport-Vasilliadis broth, and DIASALM directly after pre-enric hment in BPW. Suspected positive colonies were confirmed biochemically and serologically. DIASALM and BPLS agar were comparatively evaluated against XLT4 agar as the "gold standard" using Kappa statistic to determine the level of agreement between them. A total of 27 (24.77%) Salmonella were detected from the 109 samples. Isolation rates for XLT4, DIASALM, and BPLS were 20.20% (22 out of 109), 17.43% (19 out of 109), and 13.8% (15 out of 109), respectively. The sensitivity and agreement (Kappa statistic) with the "gold standard" for each evaluated detection method were: 70.4% and 0.69 (substantial) for DIASALM and 55.56% and 0.58 (mode rate) for BPLS. For the detection of Salmonella spp. by PCR, bacterial chromosomal DNA was extracted by boiling. Amplicons (429 bp) and (284 bp) derived from primers to the genomic random fragment (primers ST11 and ST15) and invA genes (primers 139 and 141) respectively, were confirmed as Salmonella specific on ethidium bromide-stained agarose gels. Using PCR assay Salmonella was detected 24% (13 out of 54) and 13% (7 out of 54) in broilers in farm A using primers ST11-ST15 and 139-141, respectively. Poultry species in farm B were negative for Salmonella by PCR. A specific primer was used for the detection of Salmonella enteritidis. None of Salmonella detected was Salmonella enteritidis. This study concluded that XLT4 agar is the most sensitive medium and is very specific for the isolation of Salmonella from chicken feces. DIASALM is a good medium for the isolation of Salmonella. The inability of PCR to successfully detect Salmonella specific products from all the samples that were positive for isolation is not clear. However, this would be partly explained by the presence of inhibitor factors in the DNA preparations. In addition, the primer set ST11-ST15 used in this study has not before been tested on cloacal swabs and fecal samples from poultry. Perhaps, with improved DNA extraction method may overcome the inhibitory problem and also low yield of DNA. PCR should be used together with cultivation for the detection of Salmonella especially when the serovar is to be determined

Attitudes and beliefs of Australian chiropractors' about managing back pain: A cross-sectional study

Background Chiropractors are frequent providers of care for patients with lower back pain. Biopsychosocial approaches to managing patients are regarded as best practice and are gaining wider acceptance. Recent evidence suggests that practitioners' attitudes and beliefs may also have an important effect on patients' recovery from back pain. Past studies have pooled manual therapists from differing professions. Dissonant findings have been hypothesised as being a result of the chiropractic subpopulation within multi-practitioner participant pools who are hypothesised to focus on biomedical aspects of treatment and minimize biopsychosocial dimensions. The aim of this study is to determine whether a study population of only chiropractors would demonstrate similar attitudes and beliefs to other manual therapists' biopsychosocial or biomedical approach to the management of their patients. Methods A survey of chiropractors in Victoria Australia in September 2010 was undertaken utilising the Pain Attitude and Belief Scale (PABS.PT), a tool which has been developed to determine the orientation (biopsychosocial or biomedical approach) of practitioners to the management of people with low back pain. The survey also obtained demographic data from respondents to determine whether variables such as education, gender or practice related factors influenced their orientation. Results The overall response rate was 29% (n = 218). The majority of the sample was male (68%), with a mean age of 44 years. The 6 point Likert scale scores were 34.5 (6.3) for the biomedical factor scale and 31.4 (4.1) for the biopsychosocial scale. Internal consistency of the psychosocial subscale was poor. None of the demographic variables were found to influence the biomedical or psychosocial scales. Conclusions Chiropractors in the state of Victoria were found to have similar biomedical and psychosocial orientations in their attitudes and beliefs when compared to other manual therapists' levels of previous studies from differing cultural and educational backgrounds. This study was unable to replicate any of the relationships from past studies with any of the demographic variables. The psychosocial scale internal consistency may be a significant factor in this non-finding. Future research should address the identification of more robust items of the biopsychosocial attitudes of Victorian chiropractors toward treating lower back pain

Low-threshold organic laser based on an oligofluorene truxene with low optical losses

A blue-emitting distributed feedback laser based on a star-shaped oligofluorene truxene molecule is presented. The gain, loss, refractive index, and (lack of) anisotropy are measured by amplified spontaneous emission and variable-angle ellipsometry. The waveguide losses are very low for an organic semiconductor gain medium, particularly for a neat film. The results suggest that truxenes are promising for reducing loss, a key parameter in the operation of organic semiconductor lasers. Distributed feedback lasers fabricated from solution by spin-coating show a low lasing threshold of 270 W/cm(2) and broad tunability across 25 nm in the blue part of the spectrum

Soil quality: to regulate or to manage?

The concept of soil quality was conceived in the early 1990s as a parallel to those of air and water quality in response to concerns about soil 'health,' sustainability and environmentally `friendly' crop production. The concept has the potential to be used by researchers to link soil research issues to broader environmental issues when applying for funds. However, unlike air and water, soils have no defined 'pure' state against which measures can be taken and comparisons made. The physical, chemical and biological composition of soils varies widely and no single attribute or soil type can be established as a standard. The choice of appropriate soil properties and their standards depends on the use to which the soil is put. We suggest concentrating on quality management of the soil, rather than managing generically-chosen soil properties, collectively called soil 'quality'. Quality management puts the onus on managers to use the technical tools that are readily available to manage soils and landscapes, and on scientists to develop new tools

Mechanism, localization and cure of atrial arrhythmias occurring after a new intraoperative endocardial radiofrequency ablation procedure for atrial fibrillation

AbstractOBJECTIVESThe purpose of this study was to test a new pattern of radiofrequency ablation for atrial fibrillation (AFib) intended to optimize atrial activation, and to demonstrate the usefulness of catheter techniques for mapping and ablation of postoperative atrial arrhythmias.BACKGROUNDLinear radiofrequency lesions have been used to cure AFib, but the optimal pattern of lesions is unknown and postoperative tachyarrhythmias are common.METHODSA radial pattern of linear radiofrequency lesions (Star) was made using an endocardial open surgical approach in 25 patients. Postoperative arrhythmias were induced and characterized during electrophysiological studies in 15 patients.RESULTSThe AFib was abolished in most patients (91%), but atrial flutter (AFlut) occurred in 96% of patients postoperatively. At postoperative electrophysiological studies, 37 flutter morphologies were studied in 15 patients (46% spontaneous, cycle length [CL] 223 ± 25 ms). Seven mechanisms (lesions discontinuity, n = 6; focal mechanism, n = 1) of AFlut were characterized in six patients. In these cases, flutter was abolished using further catheter radiofrequency ablation. In the remaining cases, flutter was usually localized to an area involving the interatrial septum, but no critical isthmus was identified for ablation. After 16 ± 10 months, 15 patients (65%) were asymptomatic with (n = 3) or without (n = 12) antiarrhythmic medications. Eight (35%) patients had persistent arrhythmias. Postoperative atrial electrical activation was near physiological.CONCLUSIONSThe AFib may be abolished using a radial pattern of linear endocardial radiofrequency lesions, but postoperative AFlut is common even when lesions are made under optimal conditions. Endocardial mapping techniques can be used to characterize the flutter mechanisms, thus enabling subsequent successful catheter ablation

Breakdown of correspondence in chaotic systems: Ehrenfest versus localization times

Breakdown of quantum-classical correspondence is studied on an experimentally realizable example of one-dimensional periodically driven system. Two relevant time scales are identified in this system: the short Ehrenfest time t_h and the typically much longer localization time scale T_L. It is shown that surprisingly weak modification of the Hamiltonian may eliminate the more dramatic symptoms of localization without effecting the more subtle but ubiquitous and rapid loss of correspondence at t_h.Comment: 4 pages, 5 figures, replaced with a version submitted to PR

Pre-existing virus-specific CD8+ T-cells provide protection against pneumovirus-induced disease in mice

Pneumoviruses such as pneumonia virus of mice (PVM), bovine respiratory syncytial virus (bRSV) or human (h)RSV are closely related pneumoviruses that cause severe respiratory disease in their respective hosts. It is well-known that T-cell responses are essential in pneumovirus clearance, but pneumovirus-specific T-cell responses also are important mediators of severe immunopathology. In this study we determined whether memory- or pre-existing, transferred virus-specific CD8 + T-cells provide protection against PVM-induced disease. We show that during infection with a sublethal dose of PVM, both natural killer (NK) cells and CD8 + T-cells expand relatively late. Induction of CD8 + T-cell memory against a single CD8 + T-cell epitope, by dendritic cell (DC)-peptide immunization, leads to partial protection against PVM challenge and prevents Th2 differentiation of PVM-induced CD4 T-cells. In addition, adoptively transferred PVM-specific CD8 + T-cells, covering the entire PVM-specific CD8 + T-cell repertoire, provide partial protection from PVM-induced disease. From these data we infer that antigen-specific memory CD8 + T-cells offer significant protection to PVM-induced disease. Thus, CD8 + T-cells, despite being a major cause of PVM-associated pathology during primary infection, may offer promising targets of a protective pneumovirus vaccine

Side-chain influence on the mass density and refractive index of polyfluorenes and star-shaped oligofluorene truxenes

This work is part of the TIRAMISU project, funded by the European Commission’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n◦284747 and the Engineering and Physical Sciences Research Council (EPSRC) grants EP/J009016/1 and EP/F059922/1. I.D.W.S. and P.J.S. are Royal Society Wolfson Research Merit Award holders.The density of organic semiconductor films is an important quantity because it is related to intermolecular spacing which in turn determines the electronic and photophysical properties. We report thin film density and refractive index measurements of polyfluorenes and star-shaped oligofluorene truxene molecules. An ellipsometer and a procedure using a spectrophotometer were used to determine film thickness and mass of spin-coated films, respectively. We present a study of the effect of alkyl side-chain length on the volumetric mass density and refractive index of the materials studied. The density measured for poly(9,9-di-n-octylfluorene) (PF8) was 0.88 ± 0.04 g/cm3 and decreased with longer alkyl side chains. For the truxene molecule with butyl side chains (T3 butyl), we measured a density of 0.90 ± 0.04 g/cm3, which also decreased with increasing side-chain length.PostprintPeer reviewe

Ancient Gondwana break-up explains the distribution of the mycoheterotrophic family Corsiaceae (Liliales)

Plant science