Current and emerging screening methods to identify post-head-emergence frost adaptation in wheat and barley

Cereal crops can suffer substantial damage if frosts occur at heading. Identification of post-head-emergence frost (PHEF) resistance in cereals poses a number of unique and difficult challenges. Many decades of research have failed to identify genotypes with PHEF resistance that could offer economically significant benefit to growers. Research and breeding gains have been limited by the available screening systems. Using traditional frost screening systems, genotypes that escape frost injury in trials due to spatial temperature differences and/or small differences in phenology can be misidentified as resistant. We believe that by improving techniques to minimize frost escapes, such ofalse-positive' results can be confidently identified and eliminated. Artificial freezing chambers or manipulated natural frost treatments offer many potential advantages but are not yet at the stage where they can be reliably used for frost screening in breeding programmes. Here we describe the development of a novel photoperiod gradient method (PGM) that facilitates screening of genotypes of different phenology under natural field frosts at matched developmental stages. By identifying frost escapes and increasing the efficiency of field screening, the PGM ensures that research effort can be focused on finding genotypes with improved PHEF resistance. To maximize the likelihood of identifying PHEF resistance, we propose that the PGM form part of an integrated strategy to (i) source germplasm;(ii) facilitate high throughput screening; and (iii) permit detailed validation. PGM may also be useful in other studies where either a range of developmental stages and/or synchronized development are desired.

Portrait of Ya'akov Meir [Jacob Meyer], Head of the Rabbinical Court and President of the Consistorium of the Community of Strasbourg; France.

Caption: J. Meyer, Grand-Rabbin et President du Consistoire Israelite du Department du Bas-Rhin a Strasbourg; also translated in Hebrew

Fusarium graminearum and Fusarium pseudograminearum caused the 2010 head blight epidemics in Australia

Wheat crops in southeast Queensland (Qld) and northern New South Wales (NSW) were infected with fusarium head blight (FHB)-like symptoms during the 201011 wheat growing season. Wheat crops in this region were surveyed at soft dough or early maturity stage to determine the distribution, severity, aetiology and toxigenicity of FHB. FHB was widespread on bread wheat and durum, and Fusarium graminearum and/or F.pseudograminearum were diagnosed from 42 of the 44 sites using species-specific PCR primers directly on spikelets or from monoconidial cultures obtained from spikelets. Stem base browning due to crown rot (CR) was also evident in some samples from both states. The overall FHB and CR severity was higher for NSW than Qld. Deoxynivalenol (DON) concentration of immature grains was more than 1 mg kg-1 in samples from 11 Qld and 14 NSW sites, but only 13 of 498 mature grain samples sourced from the affected areas had more than 1 mg kg-1 DON. DON concentration in straw also exceeded 1 mg kg-1 in eight Qld and all but one NSW sites but this was not linked to DON concentration of immature grains. The proportion of spikelets with positive diagnosis for F.graminearum and/or F.pseudograminearum and weather-related factors influenced DON levels in immature grains. The average monthly rainfall for AugustNovember during crop anthesis and maturation exceeded the long-term monthly average by 10150%. Weather played a critical role in FHB epidemics for Qld sites but this was not apparent for the NSW sites, as weather was generally favourable at all sites.

Quantifying northward movement rates of eastern king prawns along eastern Australia

Movement rates of eastern king prawns, Melicertus plebejus (Hess), were estimated from historical and recent conventional tag-recapture information collected across eastern Australia. Data from three studies and 2,656 tag recaptures were used. Recaptured males and females both moved east-north-east in central Queensland and north-north-east in southern Queensland and New South Wales. Over a period of one year, the estimated transition matrix reflected the species strong northerly movement and the more complex longitudinal movement, showing a very high probability of eastern movement in central Queensland and almost negligible eastern or western movement in northern New South Wales. The high exchange probability between New South Wales and Queensland waters indicated that spatial assessment models with movement rates between state jurisdictions would improve the management of this single-unit stock.

Movement-associated proteins of Potato virus A: attachment to virus particles and phosphorylation

The particles of Potato virus A (PVA; genus Potyvirus) are helically constructed filaments that contain multiple copies of a single type of coat-protein (CP) subunit and a single copy of genome-linked protein (VPg), attached to one end of the virion. Examination of negatively-stained virions by electron microscopy revealed flexuous, rod-shaped particles with no obvious terminal structures. It is known that particles of several filamentous plant viruses incorporate additional minor protein components, forming stable complexes that mediate particle disassembly, movement or transmission by insect vectors. The first objective of this work was to study the interaction of PVA movement-associated proteins with virus particles and how these interactions contribute to the morphology and function of the virus particles. Purified particles of PVA were examined by atomic force microscopy (AFM) and immuno-gold electron microscopy. A protrusion was found at one end of some of the potyvirus particles, associated with the 5' end of the viral RNA. The tip contained two virus-encoded proteins, the genome-linked protein (VPg) and the helper-component proteinase (HC-Pro). Both are required for cell-to-cell movement of the virus. Biochemical and electron microscopy studies of purified PVA samples also revealed the presence of another protein required for cell-to-cell movement the cylindrical inclusion protein (CI), which is also an RNA helicase/ATPase. Centrifugation through a 5-40% sucrose gradient separated virus particles with no detectable CI to a fraction that remained in the gradient, from the CI-associated particles that went to the pellet. Both types of particles were infectious. AFM and translation experiments demonstrated that when the viral CI was not present in the sample, PVA virions had a beads-on-a-string phenotype, and RNA within the virus particles was more accessible to translation. The second objective of this work was to study phosphorylation of PVA movement-associated and structural proteins (CP and VPg) in vitro and, if possible, in vivo. PVA virion structural protein CP is necessary for virus cell-to-cell movement. The tobacco protein kinase CK2 was identified as a kinase phosphorylating PVA CP. A major site of CK2 phosphorylation in PVA CP was identified as a single threonine within a CK2 consensus sequence. Amino acid substitutions affecting the CK2 consensus sequence in CP resulted in viruses that were defective in cell-to-cell and long-distance movement. The CK2 regulation of virion assembly and cell-to-cell movement by phosphorylation of CP was possibly due to the inhibition of CP binding to viral RNA. Four putative phosphorylation sites were identified from an in vitro phosphorylated recombinant VPg. All four were mutated and the spread of mutant viruses in two different host plants was studied. Two putative phosphorylation site mutants (Thr45 and Thr49) had phenotypes identical to that of a wild type (WT) virus infection in both Nicotiana benthamiana and N. tabacum plants. The other two mutant viruses (Thr132/Ser133 and Thr168) showed different phenotypes with increased or decreased accumulation rates, respectively, in inoculated and the first two systemically infected leaves of N. benthamiana. The same mutants were occasionally restricted to single cells in N. tabacum plants, suggesting the importance of these amino acids in the PVA infection cycle in N. tabacum.

Crinkles in connectivity: combining genetics and other types of biological data to estimate movement and interbreeding between populations

Marine species generally have large population sizes, continuous distributions and high dispersal capacity. Despite this, they are often subdivided into separate populations, which are the basic units of fisheries management. For example, populations of some fisheries species across the deep water of the Timor Trench are genetically different, inferring minimal movement and interbreeding. When connectivity is higher than the Timor Trench example, but not so high that the populations become one, connectivity between populations is crinkled. Crinkled connectivity occurs when migration is above the threshold required to link populations genetically, but below the threshold for demographic links. In future, genetic estimates of connectivity over crinkled links could be uniquely combined with other data, such as estimates of population size and tagging and tracking data, to quantify demographic connectedness between these types of populations. Elasmobranch species may be ideal targets for this research because connectivity between populations is more likely to be crinkled than for finfish species. Fisheries stock-assessment models could be strengthened with estimates of connectivity to improve the strategic and sustainable harvesting of biological resources.

Liquid bubble manometer for low differential heads

The development of a highly sensitive liquid bubble manometer which can measure low differential heads to an accuracy of 0.01 mm of water is reported in this paper. The liquid bubble consists of two miscible liquids,benzaldehyde and normal hexane (each of which is immiscible in water) in such a proportion that the bubble density is within ±2 % of the density of water. The movement of the liquid bubble, which occupies the full cross-sectional area of the glass tube containing water in the manometer, is indicative of the applied differential head to a magnified scale. The manometer is found to give excellent results in open channel flow and is recommended for use for differential heads up to 2 cm of water. The manometer is economical, simple in fabrication and with simple modifications the sensitivity of the manometer can be increased to more than 0.01 mm of water.

Do Phosphine Resistance Genes Influence Movement and Dispersal Under Starvation?

Phosphine resistance alleles might be expected to negatively affect energy demanding activities such as walking and flying, because of the inverse relationship between phosphine resistance and respiration. We used an activity monitoring system to quantify walking of Rhyzopertha dominica (F.) and a flight chamber to estimate their propensity for flight initiation. No significant difference in the duration of walking was observed between the strongly resistant, weakly resistant, and susceptible strains of R. dominica we tested, and females walked significantly more than males regardless of genotype. The walking activity monitor revealed no pattern of movement across the day and no particular time of peak activity despite reports of peak activity of R. dominica and Tribolium castaneum (Herbst) under field conditions during dawn and dusk. Flight initiation was significantly higher for all strains at 28 degrees C and 55% relative humidity than at 25, 30, 32, and 35 degrees C in the first 24 h of placing beetles in the flight chamber. Food deprivation and genotype had no significant effect on flight initiation. Our results suggest that known resistance alleles in R. dominica do not affect insect mobility and should therefore not inhibit the dispersal of resistant insects in the field.

Taste over waste: Ugly food movement winning friends

Consumer driven food trends are nothing new. “Organics”, gluten-free, and more recently buying “local” have all captured consumers, encouraging supermarkets around the globe and in Australia to respond. But the next emerging European food trend that may have the biggest impact on what we buy each week is “ugly food”.

The relationship between forward head posture and cervical muscle performance in healthy individuals

Background Forward head postures (FHP) are proposed to adversely load cervical spine structures. Neck muscles provide support for the neck, and thus an imbalance in neck muscle performance could potentially contribute to the development of FHP. Previous studies have not considered the interaction of multiple muscle groups with regard to postural orientation. Given the interdependence of muscles along the cervical spine for optimal orientation and physical support of the vertebral column, the performance of a single muscle group may not accurately reflect the coordinated ability of the muscles to maintain a neutral neck posture. Purpose The purpose of this study was to investigate the relationship between FHP and the balance between the cervical extensor and flexor muscle groups in healthy individuals. We hypothesised that the magnitude of FHP would be associated with the strength and endurance performance ratios between the cervical extensor and flexor muscle groups. Methods Twenty male and 24 female volunteers were photographed in the sagittal plane wearing surface markers. The FHP of each participant was measured via the tragus-sternum marker distance over two conditions: (1)in relaxed standing and (2)during a sustained sitting task. Maximal strength (Nm) and endurance (s) performance of the extensor and flexor muscle groups were recorded at the upper (craniocervical flexion/extension (CCF/CCE)) and lower (cervicothoracic flexion/extension (CTF/CTE)) cervical regions. Muscle performance measures were expressed as extension:flexion ratios and their relation to FHP evaluated. A stepwise multiple regression analysis using backward elimination was utilised to examine the relationship between the postural measures and the muscle performance ratio measures. Separate models were used for the two different postural conditions (standing, sustained sitting). Gender was included as a constant correction factor in all regression models. Where gender was a significant variable in the model, analyses were repeated separately for males and females. Results Greater FHP in standing was significantly associated with reduced proportional CTE to CCF strength in females (R2 = 0.21, P = 0.03) and greater proportional CTE to CTF strength in males (R2 = 0.23, P = 0.03). A greater drift into FHP during sustained sitting was associated with a relative reduction in CCE endurance proportional to CTF endurance in females only (R2 = 0.27, P = 0.017). Conclusion(s) This initial study indicates that the balance in performance between the cervical flexor and extensor muscle groups may impact FHP in healthy individuals. However, the findings were inconsistent across different muscle performance ratios and gender. Larger scale studies are therefore now needed to further clarify the relationship between FHP and muscle performance. Implications The findings suggest that relative performance of the various cervical muscle groups needs to be accounted for when considering postural correction strategies in the clinical setting, as is often recommended.

Early-season movement dynamics of phytophagous pest and natural enemies across a native vegetation-crop ecotone

There is limited understanding about how insect movement patterns are influenced by landscape features, and how landscapes can be managed to suppress pest phytophage populations in crops. Theory suggests that the relative timing of pest and natural enemy arrival in crops may influence pest suppression. However, there is a lack of data to substantiate this claim. We investigate the movement patterns of insects from native vegetation (NV) and discuss the implications of these patterns for pest control services. Using bi-directional interception traps we quantified the number of insects crossing an NV/crop ecotone relative to a control crop/crop interface in two agricultural regions early in the growing season. We used these data to infer patterns of movement and net flux. At the community-level, insect movement patterns were influenced by ecotone in two out of three years by region combinations. At the functional-group level, pests and parasitoids showed similar movement patterns from NV very soon after crop emergence. However, movement across the control interface increased towards the end of the early-season sampling period. Predators consistently moved more often from NV into crops than vice versa, even after crop emergence. Not all species showed a significant response to ecotone, however when a response was detected, these species showed similar patterns between the two regions. Our results highlight the importance of NV for the recruitment of natural enemies for early season crop immigration that may be potentially important for pest suppression. However, NV was also associated with crop immigration by some pest species. Hence, NV offers both opportunities and risks for pest management. The development of targeted NV management may reduce the risk of crop immigration by pests, but not of natural enemies.

Does flexibility of the cervical and thoracic spine influence forward head posture in healthy individuals?

Background: Forward head posture (FHP) is a commonly reported deviation from a neutral neck posture, usually implying a protracted head position in the sagittal plane. Habitual FHP has been associated with a higher incidence of painful neck disorders, changes in joint mobility and muscle behaviour within the cervicothoracic regions. One factor that has received attention in the literature with regards to FHP is flexibility of the neck. A number of previous studies have previously investigated the relationship between neck flexibility and neck posture under different conditions, but at present this relationship is unclear.

National Council of Jewish Women, New York Section records, undated, 1895-2004.

These records document New York Section’s early history to the present, representing a significant portion of its work in community programming and advocacy, as well as its supporting administrative, fundraising, membership, and public relations activities. As a section of the National Council, its records also include a substantial amount of material regarding the National Organization’s programs, events, publications, and reports, dating from 1896 through 1999.

A Framework for Detecting Glaucomatous Progression in the Optic Nerve Head of an Eye Using Proper Orthogonal Decomposition

Glaucoma is the second leading cause of blindness worldwide. Often, the optic nerve head (ONH) glaucomatous damage and ONH changes occur prior to visual field loss and are observable in vivo. Thus, digital image analysis is a promising choice for detecting the onset and/or progression of glaucoma. In this paper, we present a new framework for detecting glaucomatous changes in the ONH of an eye using the method of proper orthogonal decomposition (POD). A baseline topograph subspace was constructed for each eye to describe the structure of the ONH of the eye at a reference/baseline condition using POD. Any glaucomatous changes in the ONH of the eye present during a follow-up exam were estimated by comparing the follow-up ONH topography with its baseline topograph subspace representation. Image correspondence measures of L-1-norm and L-2-norm, correlation, and image Euclidean distance (IMED) were used to quantify the ONH changes. An ONH topographic library built from the Louisiana State University Experimental Glaucoma study was used to evaluate the performance of the proposed method. The area under the receiver operating characteristic curves (AUCs) was used to compare the diagnostic performance of the POD-induced parameters with the parameters of the topographic change analysis (TCA) method. The IMED and L-2-norm parameters in the POD framework provided the highest AUC of 0.94 at 10 degrees. field of imaging and 0.91 at 15 degrees. field of imaging compared to the TCA parameters with an AUC of 0.86 and 0.88, respectively. The proposed POD framework captures the instrument measurement variability and inherent structure variability and shows promise for improving our ability to detect glaucomatous change over time in glaucoma management.

Post-head-emergence frost in wheat and barley: defining the problem, assessing the damage, and identifying resistance

Radiant frost is a significant production constraint to wheat (Triticum aestivum) and barley (Hordeum vulgare), particularly in regions where spring-habit cereals are grown through winter, maturing in spring. However, damage to winter-habit cereals in reproductive stages is also reported. Crops are particularly susceptible to frost once awns or spikes emerge from the protection of the flag leaf sheath. Post-head-emergence frost (PHEF) is a problem distinct from other cold-mediated production constraints. To date, useful increased PHEF resistance in cereals has not been identified. Given the renewed interest in reproductive frost damage in cereals, it is timely to review the problem. Here we update the extent and impacts of PHEF and document current management options to combat this challenge. We clarify terminology useful for discussing PHEF in relation to chilling and other freezing stresses. We discuss problems characterizing radiant frost, the environmental conditions leading to PHEF damage, and the effects of frost at different growth stages. PHEF resistant cultivars would be highly desirable, to both reduce the incidence of direct frost damage and to allow the timing of crop maturity to be managed to maximize yield potential. A framework of potential adaptation mechanisms is outlined. Clarification of these critical issues will sharpen research focus, improving opportunities to identify genetic sources for improved PHEF resistance.