Developmental and physiological traits associated with high yield and stay-green phenotype in wheat

Water availability is a key limiting factor in wheat production in the northern grain belt of Australia. Varieties with improved adaptation to such conditions are actively sought. The CIMMYT wheat line SeriM82 has shown a significant yield advantage in multi-environment screening trials in this region. The objective of this study was to identify the physiological basis of the adaptive traits underpinning this advantage. Six detailed experiments were conducted to compare the growth, development, and yield of SeriM82 with that of the adapted cultivar, Hartog. The experiments were undertaken in field environments that represented the range of moisture availability conditions commonly encountered by winter crops grown on the deep Vertosol soils of this region. The yield of SeriM82 was 6-28% greater than that of Hartog, and SeriM82 exhibited a stay-green phenotype by maintaining green leaf area longer during the grain-filling period in all environments where yield was significantly greater than Hartog. However, where the availability of deep soil moisture was limited, SeriM82 failed to exhibit significantly greater yield or to express the stay-green phenotype. Thus, the stay-green phenotype was closely associated with the yield advantage of SeriM82. SeriM82 also exhibited higher mean grain mass than Hartog in all environments. It is suggested that small differences in water use before anthesis, or greater water extraction from depth after anthesis, could underlie the stay-green phenotype. The inability of SeriM82 to exhibit stay-green and higher yield where deep soil moisture was depleted indicates that extraction of deep soil moisture is important.

Architectural modelling of maize under water stress

Two field experiments using maize (Pioneer 31H50) and three watering regimes [(i) irrigated for the whole crop cycle, until anthesis, (ii) not at all (experiment 1) and (iii) fully irrigated and rain grown for the whole crop cycle (experiment 2)] were conducted at Gatton, Australia, during the 2003-04 season. Data on crop ontogeny, leaf, sheath and internode lengths and leaf width, and senescence were collected at 1- to 3-day intervals. A glasshouse experiment during 2003 quantified the responses of leaf shape and leaf presentation to various levels of water stress. Data from experiment 1 were used to modify and parameterise an architectural model of maize (ADEL-Maize) to incorporate the impact of water stress on maize canopy characteristics. The modified model produced accurate fitted values for experiment 1 for final leaf area and plant height, but values during development for leaf area were lower than observed data. Crop duration was reasonably well fitted and differences between the fully irrigated and rain-grown crops were accurately predicted. Final representations of maize crop canopies were realistic. Possible explanations for low values of leaf area are provided. The model requires further development using data from the glasshouse study and before being validated using data from experiment 2 and other independent data. It will then be used to extend functionality in architectural models of maize. With further research and development, the model should be particularly useful in examining the response of maize production to water stress including improved prediction of total biomass and grain yield. This will facilitate improved simulation of plant growth and development processes allowing investigation of genotype by environment interactions under conditions of suboptimal water supply.

Stress Analysis of Deep Beams

In a beam whose depth is comparable to its span, the distribution of bending and shear stresses differs appreciably from those given by the ordinary flexural theory. In this paper, a general solution for the analysis of a rectangular, single-scan beam, under symmetrical loading is developed. The Multiple Fourier procedure is employed using four series by which it has been possible to satisfy all boundary and the resulting relation among the co-efficient are derives.

Stress Concentration in Post-Tensioned Prestressed Concrete Beams

The use of the multiple Fourier method to analyses the stress distribution in the and regions of as a post-tensioned prestressed concrete beam had shown. The multiple Fourier method demonstrated have is a relatively new method for solving those problems for which the “Saint Vansant principle” is not applicable, The actual three-dimensional problem and a two-dimensional simplified representation of it are treated. The two-dimensional case is treated first and rather completely to gain further experience with multiple Fourier procedure, the appropriate Galerkin Vector for the three-dimensional case is found and the required relations between the arbitrary functions are stated.

Work Stress and Early Atherosclerosis: Do Genetic Background and Pre-Employment Risk Factors Explain Conflicting Findings?

According to the models conceptualizing work stress, increased risk of health problems arise when high job demands co-occur with low job control (the demand-control model) or the efforts invested by the employee are disproportionately high compared to the rewards received (effort-reward imbalance model). This study examined the association between work stress and early atherosclerosis with particular attention to the role of pre-employment risk factors and genetic background in this association. The subjects were young healthy adults aged 24-39 who were participating in the 21-year follow-up of the ongoing prospective "Cardiovascular Risk in Young Finns" study in 2001-2002. Work stress was evaluated with questionnaires on demand-control model and on effort-reward model. Atherosclerosis was assessed with ultrasound of carotid artery intima-media thickness (IMT). In addition, risk for enhanced atherosclerotic process was assessed by measuring with heart rate variability and heart rate. Pre-employment risk factors, measured at age 12 to 18, included such as body mass index, blood lipids, family history of coronary heart disease, and parental socioeconomic position. Variants of the neuregulin-1 were determined using genomic DNA. The results showed that higher work stress was associated with higher IMT in men. This association was not attenuated by traditional risk factors of atherosclerosis and coronary heart disease or by pre-employment risk factors measured in adolescence. Neuregulin-1 gene moderated the association between work stress and IMT in men. A significant association between work stress and IMT was found only for the T/T genotype of the neuregulin-1 gene but not for other genotypes. Among women an association was found between higher work stress and lower heart rate variability, suggesting higher risk for developing atherosclerosis. These associations could not be explained by demographic characteristics or coronary risk factors. The present findings provide evidence for an association between work stress and atherosclerosis in relatively young population. This association seems to be modified by genetic influences but it does not appear to be confounded by pre-employment adolescent risk factors.

Childhood and adolescent antecedents of work stress and early atherosclerosis

Work stress is after musculoskeletal disorders the second most common work-related health problem in the European Union, affecting 28% of EU employees. Furthermore, a 50% excessive cardiovascular disease risk among employees with work stress is reported. High job demands combined with low job control according to the Job Demands-Job Control model, or high effort combined with low rewards according to Effort-Reward Imbalance model, are likely to produce work stress in the majority of employees. Atherosclerotic wall thickening is a validated marker of an increased risk of cardiovascular disease. This study examined the role of childhood and adolescent factors as antecedents of work stress and early atherosclerosis, and in the relationship between them. The Cardiovascular Risk in Young Finns Study, (the CRYF project) started in 1980 when the participants were at the age of three to 18 years. Follow-ups have been conducted every three years until 1992, after that in 1997 and 2001, and the latest is ongoing in 2008. The participants parents reported their socioeconomic position in 1980 and 1983, and their life satisfaction in 1983. Biological risk factors were measured in 1980 and 2001. Type A behaviour was reported in 1986, 1989 and 2001. In the 2001 follow-up when the participants were aged 24 to 39, work stress was assessed from responses to questionnaires on job demands-job control and effort-reward imbalance, and education. Ultrasound measurement of the carotid intima-media thickness (CIMT) was used to assess atherosclerosis. There were 755, 746, 1014 and 494 participants in studies I-IV, respectively. The results showed that low parental socioeconomic position and parental life dissatisfaction during childhood and adolescence predicted higher levels of job strain 18 years later, and that education mediated the relationship between parental socioeconomic position and job strain. Childhood and adolescent family factors were not related to the effort-reward imbalance. Parental life satisfaction was associated with high rewards at work among the men, and high parental socioeconomic position was associated with high reward among the women. Among the men, the eagerness-energy component of Type A behaviour across different developmental periods predicted increased CIMT. Among the women, hard-driving component of Type A behaviour predicted decreased CIMT. Low leadership characteristic in adolescence and early adulthood was associated with both high job strain and increased CIMT, and attenuated the relationship between job strain and CIMT to non-significance in men. The current findings add to the literature on the relationship between job strain and health literature in adopting a developmental perspective. The results imply that work stress does not completely originate from work. There are childhood and adolescent environmental and dispositional effects on work stress and CIMT several years later, and these partly seem to operate through educational attainment.

Growth and physiological response of six Australian rainforest tree species to a light gradient

An understanding of growth and photosynthetic potential of subtropical rainforest species to variations in light environment can be useful for determining the sequence of species introductions in rainforest restoration projects and mixed species plantations. We examined the growth and physiology of six Australian subtropical rainforest tree species in a greenhouse consisting of three artificial light environments (10%, 30%, and 60% full sunlight). Morphological responses followed the typical sun-shade dichotomy, with early and late secondary species (Elaeocarpus grandis, Flindersia brayleyana, Flindersia schottiana, and Gmelina leichhardtii) displaying higher relative growth rate (RGR) compared to mature stage species (Cryptocarya erythroxyion and Heritiera trifoliolatum). Growth and photosynthetic performance of most species reached a maximum in 30-60% full sunlight. Physiological responses provided limited evidence of a distinct dichotomy between early and late successional species. E. grandis and F brayleyana, provided a clear representation of early successional species, with marked increase in Am in high light and an ability to down regulate photosynthetic machinery in low light conditions. The remaining species (F. schottiana, G. leichhardtii, and H. trifoliolatum) were better represented as failing along a shade-tolerant continuum, with limited ability to adjust physiologically to an increase or decrease in light, maintaining similar A(max) across all light environments. Results show that most species belong to a shade-tolerant constituency, with an ability to grow and persist across a wide range of light environments. The species offer a wide range of potential planting scenarios and silvicultural options, with ample potential to achieve rapid canopy closure and rainforest restoration goals.

Regrouping unfamiliar animals in the weeks prior to slaughter has few effects on physiology and meat quality in Bos taurus feedlot steers

The response of cattle to alterations in social groupings can lead to physiological changes that affect meat quality. Feedlot practices frequently lead to a proportion of cattle in a pen being drafted for slaughter with the balance retained for a further period until they meet market specifications. An ability to regroup such retained cattle for short periods without consequences for meat quality would facilitate efficient use of feedlot pen space. The current experiment examined the impact on physiological variables and meat quality of regrouped British breed steers 4, 2 or 1 week before dispatch for slaughter. There was little effect of regrouping cattle on physiological variables associated with stress responses. Physical assessment of meat quality indicated that regrouping steers 1 week before slaughter led to higher compression and a tendency for higher peak force values in animals from one genotype than in their respective controls (1.89 v. 1.71 ± 0.05 kg, P = 0.017); however, these assessments were not matched by changes in sensory perception of meat quality. Average daily gain during feedlot finishing was negatively related to the temperament measure and flight time. It was also associated with breed, white cell count, plasma cortisol and haemoglobin at the midpoint of the 70-day finishing period. The results confirm the impact of flight time on growth rate during feedlot finishing and that regrouping cattle less than 2 weeks before slaughter may reduce meat quality.

Structural and functional characterization of dendritic arbors and GABAergic synaptic inputs on interneurons and principal cells in the rat basolateral amygdala

The basolateral amygdala (BLA) is a complex brain region associated with processing emotional states, such as fear, anxiety, and stress. Some aspects of these emotional states are driven by the network activity of synaptic connections, derived from both local circuitry and projections to the BLA from other regions. Although the synaptic physiology and general morphological characteristics are known for many individual cell types within the BLA, the combination of morphological, electrophysiological, and distribution of neurochemical GABAergic synapses in a three-dimensional neuronal arbor has not been reported for single neurons from this region. The aim of this study was to assess differences in morphological characteristics of BLA principal cells and interneurons, quantify the distribution of GABAergic neurochemical synapses within the entire neuronal arbor of each cell type, and determine whether GABAergic synaptic density correlates with electrophysiological recordings of inhibitory postsynaptic currents. We show that BLA principal neurons form complex dendritic arborizations, with proximal dendrites having fewer spines but higher densities of neurochemical GABAergic synapses compared with distal dendrites. Furthermore, we found that BLA interneurons exhibited reduced dendritic arbor lengths and spine densities but had significantly higher densities of putative GABAergic synapses compared with principal cells, which was correlated with an increased frequency of spontaneous inhibitory postsynaptic currents. The quantification of GABAergic connectivity, in combination with morphological and electrophysiological measurements of the BLA cell types, is the first step toward a greater understanding of how fear and stress lead to changes in morphology, local connectivity, and/or synaptic reorganization of the BLA.

Mortality and blood loss by blue swimmer crabs (Portunus pelagicus) after simulated capture and discarding from gillnets

Two laboratory experiments were carried out to quantify the mortality and physiological responses of juvenile blue swimmer crabs (Portunus pelagicus) after simulated gillnet entanglement, air exposure, disentanglement, and discarding. In both experiments, all but control blue swimmer crabs were entangled in 1-m(2) gillnet panels for 1 h, exposed to air for 2 min, subjected to various treatments of disentanglement ranging between the forceful removal of none, one, two, and four appendages, then "discarded" into individual experimental tanks and monitored for 10 d. In Experiment 1, mortalities were associated with the number of appendages removed and the occurrence of unsealed wounds. In Experiment 2, live blue swimmer crabs were sampled for blood at 2 min and 6, 24, and 72 h post-discarding to test for the effects of disentanglement and appendage removal on total haemocyte counts, clotting times, protein levels (by refractive index), and blood ion concentrations. Compared with blue swimmer crabs that had sealed or no wounds, those with unsealed wounds had lower total haemocyte counts, protein, and calcium concentrations and increased clotting ties and magnesium and sodium levels. Induced autotomy, as opposed to the arbitrary, forceful removal of a appendages has the potential to minimize the mortality and stress of discarded, juvenile blue swimmer crabs.

Posttraumatic stress symptoms among school personnel after the Jokela school shooting : A longitudial study of exposure, interventions, and symptom changes

Objectives. School personnel who are exposed to school violence are at risk in developing post traumatic stress disorder (PTSD). In Finland there have been two such events in recent years, Jokela school shooting on 7.11.2007 and Kauhajoki school shooting about a year later. The aim of the present study was to examine the presence and change in PTSD symptoms during the first year after the Jokela school shooting. A second aim was to study how the initial exposure and treatment affects the symptom levels of PTSD. There were four hypotheses: 1) The PTSD symptoms are higher for the people who were exposed to the school shooting than for the people who did not face the stressor. 2) The PTSD symptoms increase in the follow up for the people at the school which was not attacked because of the second incident brought up the memories from the Jokela school shooting. 3) Those who have greater exposure to the shooting will have higher level of PTSD symptoms at both 4 and 11 months after the shooting than those who were not directly exposed to the shooting. 4) The PTSD symptoms are reduced more in the group that starts treatment right after the traumatic event than in other groups. Methods. A sample of 24 members of Jokela school personnel were examined four months after the incident and 16 were reassessed 11 month after the incident. To study the change and level of symptoms in other schools during the same period, a group with no exposure to the shooting was used as a control group (n=22). The assessment included Post Traumatic Stress Disorder Checklist Specific (PCL-S) and a social and professional support questionnaire. In addition questions about timing of support and experiences of psychological debriefing were asked. Results and conclusions. Most participants in the study group experienced some symptoms of PTSD at both 4 and 11 months. In both measures three participants from the study group fulfilled the diagnostic criteria for PTSD. The study group and control group differed significantly in overall symptom levels. The study group had more PTSD symptoms in the first measure but in the follow-up the study group’s PTSD symptoms decreased and the control group’s increased. There was a significant change in the study groups PTSD symptom level for those who started treatment right after the traumatic event. The results from this study showed that an exposure to school shooting has long-term effects on school personnel. The findings suggest that it is crucial to plan a comprehensive and long-term treatment for school personnel in the aftermath of school shooting.

Row spacing and planting density effects on the growth and yield of sugarcane. 2. Strategies for the adoption of controlled traffic.

Controlled traffic (matching wheel and row spacing) is being promoted as a means to manage soil compaction in the Australian sugar industry. However, machinery limitations dictate that wider row spacings than the standard 1.5-m single row will need to be adopted to incorporate controlled traffic and many growers are reluctant to widen row spacing for fear of yield penalties. To address these concerns, contrasting row configuration and planting density combinations were investigated for their effect on cane and sugar yield in large-scale experiments in the Gordonvale, Tully, Ingham, Mackay, and Bingera (near Bundaberg) sugarcane-growing regions of Queensland, Australia. The results showed that sugarcane possesses a capacity to compensate for different row configurations and planting densities through variation in stalk number and individual stalk weight. Row configurations ranging from 1.5-m single rows (the current industry standard) to 1.8-m dual rows (50 cm between duals), 2.1-m dual (80 cm between duals) and triple ( 65 cm between triples) rows, and 2.3-m triple rows (65 cm between triples) produced similar yields. Four rows (50 cm apart) on a 2.1-m configuration (quad rows) produced lower yields largely due to crop lodging, while a 1.8-m single row configuration produced lower yields in the plant crop, probably due to inadequate resource availability (water stress/limited radiation interception). The results suggest that controlled traffic can be adopted in the Australian sugar industry by changing from a 1.5-m single row to 1.8-m dual row configuration without yield penalty. Further, the similar yields obtained with wider row configurations (2 m or greater with multiple rows) in these experiments emphasise the physiological and environmental plasticity that exists in sugarcane. Controlled traffic can be implemented with these wider row configurations (>2 m), although it will be necessary to carry out expensive modifications to the current harvester and haul-out equipment. There were indications from this research that not all cultivars were suited to configurations involving multiple rows. The results suggest that consideration be given to assessing clones with different growth habits under a range of row configurations to find the most suitable plant types for controlled traffic cropping systems.

Sovelletun rentoutuksen vaikutus psyykkiseen työhyvinvointiin ja sykevaihteluun

Research reveals that more than every fourth Finn experiences work-related exhaustion to some degree. Stress and exhaustion have psychological and physical expressions. The main physical factor in stress is the overloading of the autonomic nervous system, which can be measured for instance by variations of heart rate. Studies show that the work field, management and authority of the work, skill developmental possibilities, and social support inhibit stress overload. The practising of self-relaxation techniques possible inhibits working stress and exhaustion. In this study of preventive rehabilitation, the focus was on the effects of the training of applied relaxation on psychological and physiological variables of stress and empowerment of resources. Participants (n=73) were basically healthy and capable of working, 25-40 of age, workers from the field of mental work. They practised applied relaxation under group conduction for seven weeks. The aim was to learn to relax easily even in everyday occasions. The subjects were tested thirdly. After the first measurement, they were grouped into two groups, of which the first group started the relaxation training. The second group began practising half a year after the second measurement. The third measurement was done one year after the beginning of the study. It was hypothesised that the training of applied relaxation would significantly reduce stress on both psychological and physiological variables and that these variables would correlate positively. Results revealed that the training of applied relaxation reduced psychological stress symptoms rather modestly. The changes were more significant in women, who experienced a slight increase in self-directivity. Physical changes were slight decreases of the sympathetic activation. The correlations of psychological and physiological variables were modest. Some changes were reduced after the active training. There was a positive interrelation between experienced work-related demands of efficiency, insufficient social support and exhaustion. There was a tendency to significance between skill developmental possibilities and psychological stress symptoms. Further implications of the results were discussed.

Stress-induced phase transformation and pseudo-elastic/pseudo-plastic recovery in intermetallic Ni-Al nanowires

Extensive molecular dynamics (MD) simulations have been performed in a B2-NiAl nanowire using an embedded atom method (EAM) potential. We show a stress induced B2 -> body-centered-tetragonal (BCT) phase transformation and a novel temperature and cross-section dependent pseudo-elastic/pseudo-plastic recovery from such an unstable BCT phase with a recoverable strain of similar to 30% as compared to 5-8% in polycrystalline materials. Such a temperature and cross-section dependent pseudo-elastic/pseudo-plastic strain recovery can be useful in various interesting applications of shape memory and strain sensing in nanoscale devices. Effects of size, temperature, and strain rate on the structural and mechanical properties have also been analyzed in detail. For a given size of the nanowire the yield stress of both the B2 and the BCT phases is found to decrease with increasing temperature, whereas for a given temperature and strain rate the yield stress of both the B2 and the BCT phase is found to increase with increase in the cross-sectional dimensions of the nanowire. A constant elastic modulus of similar to 80 GPa of the B2 phase is observed in the temperature range of 200-500 K for nanowires of cross-sectional dimensions in the range of 17.22-28.712 angstrom, whereas the elastic modulus of the BCT phase shows a decreasing trend with an increase in the temperature.