Effect of heat wave on N2 fixation and N remobilisation of lentil (Lens culinaris MEDIK) grown under free air CO2 enrichment in a mediterranean-type environment.

The stimulatory effect of elevated [CO2 ] (e[CO2 ]) on crop production in future climates is likely to be cancelled out by predicted increases in average temperatures. This effect may become stronger through more frequent and severe heat waves, which are predicted to increase in most climate change scenarios. Whilst the growth and yield response of some legumes grown under the interactive effect of e[CO2 ] and heat waves has been studied, little is known about how N2 fixation and overall N metabolism is affected by this combination. To address these knowledge gaps, two lentil genotypes were grown under ambient [CO2 ] (a[CO2 ], ~400 µmol·mol-1 ) and e[CO2 ] (~550 µmol·mol-1 ) in the Australian Grains Free Air CO2 Enrichment facility and exposed to a simulated heat wave (3-day periods of high temperatures ~40 °C) at flat pod stage. Nodulation and concentrations of water-soluble carbohydrates (WSC), total free amino acids, N and N2 fixation were assessed following the imposition of the heat wave until crop maturity. Elevated [CO2 ] stimulated N2 fixation so that total N2 fixation in e[CO2 ]-grown plants was always higher than in a[CO2 ], non-stressed control plants. Heat wave triggered a significant decrease in active nodules and WSC concentrations, but e[CO2 ] had the opposite effect. Leaf N remobilization and grain N improved under interaction of e[CO2 ] and heat wave. These results suggested that larger WSC pools and nodulation under e[CO2 ] can support post-heat wave recovery of N2 fixation. Elevated [CO2 ]-induced accelerated leaf N remobilisation might contribute to restore grain N concentration following a heat wave.

Predictors of demand for emergency prehospital care: an Australian study.

INTRODUCTION: Determining the predictors of demand for emergency prehospital care can assist ambulance services in undertaking policy and planning activities. HYPOTHESIS: Demand for prehospital care can be explained by demographic, health status, and economic determinants. METHODS: The study used a cross-sectional design to investigate the association of demographic, health status, and insurance factors with the use of prehospital, ambulance care. Core data items including age, gender, marital status, country of origin, triage score, diagnosis, time of presentation, method of arrival, and patient disposition were collected for every patient who presented at the Emergency Department of the study hospital over a four-month period. Ambulance usage was analysed using Poisson regression. RESULTS: For the 10,229 patients surveyed, only a small number were triaged as having the highest level of urgent medical need (0.8%), but the majority of these used prehospital emergency medical care (90.2%). Predictors of ambulance use included age > 65 years (Prevalence Ratio [PR] = 2.92; 95% confidence interval [CI]: 2.35-3.63), being married or in a de-facto relationship (PR = 0.69; 95% CI: 0.60-0.79) or divorced, separated, or widowed (PR = 0.83; 95% CI: 0.70-0.98), triage score level 1 or 2 (PR = 1.95; 95% CI: 1.68-2.28), or triage score level 3 (PR = 1.54; 95% CI: 1.38-1.72), diagnosis involving either mental (PR = 4.29; 95% CI: 1.84-10.01), nervous (PR = 2.74; 95% CI: 1.19-6.31) or trauma (PR = 2.33; 95% CI: 1.03-5.27) conditions, and insurance status (PR = 1.54; 95% CI: 1.40-1.71). Ethnicity, gender, and time of day were not associated with usage. CONCLUSION: Demand for ambulance services can be predicted by a number of demographic, medical status, and insurance variables. Age and triage levels are key influences on demand for ambulance services. Ambulance insurance status provides an economic incentive to use ambulance services regardless of the urgency of the medical condition.

Early defibrillation in out-of-hospital sudden cardiac death: an Australian experience.

All patients with primary cardiac disease presenting with out-of-hospital sudden cardiac death (OH-SCD) to a provincial hospital were reviewed retrospectively over a 5-year period from 1985 to 1989. This coincided with the introduction of out-of-hospital defibrillation (OH-DEFIB) by ambulance officers. Of 215 patients, 17 (9%) survived to leave hospital alive, 15 of whom underwent OH-DEFIB. There was an increase in survivors from 4%, prior to OH-DEFIB, to 9% of all cardiac arrests, but this was not statistically significant (P = 0.3). However, long term survival amongst immediate survivors was associated with a statistically significant improvement following the introduction of OH-DEFIB (15 of 30 (50%) vs. 2 of 19 (10.5%), P < 0.01). Mean call-out, at-scene and transfer times did not significantly vary between survivors and non-survivors. A total of 155 (72%) had a known cardiac history, with the majority (74%) of arrests occurring at home. Of 134 witnessed arrests, only 46 (34%) underwent bystander-initiated cardiopulmonary resuscitation (CPR). A programme in CPR aimed at relatives of known cardiac patients, and the adoption of a paramedic protocol which improves oxygenation at the time of arrest are recommended.

Filial cannibalism in fishes: Why do parents eat their offspring?

Filial cannibalism (the eating of one's own offspring) occurs in a variety of taxa, but is especially prevalent in fishes with parental care. Recent research supports a central tenet of parental-investment theory; that is, parents consume their offspring when it maximizes their lifetime reproductive success. This review outlines the theoretical framework used to explain the adaptive significance of filial cannibalism, evaluates experimental studies to test some predictions of this theory and discusses how the occurrence of filial cannibalism affects other aspects of a species' reproductive ecology.

Hidden reproductive costs in the three-spined stickleback (Gasterosteus aculeatus).

The costs of parental behaviour (fanning) were examined in male 1+ and 2+ three-spined sticklebacks (Gasterosteus aculeatus) by comparing the loss of wet mass incurred by starved parental males during the egg care period to those incurred by starved non-parental males during this same period. To evaluate which tissues were most affected, we compared the wet and dry masses of the tissues in our starved fish with those of an additional group of fed non-parental fish. While parental and non-parentals did not differ in their absolute loss of wet mass (two age classes combined), parentals had a significantly lower total dry mass than both fed and starved non-parentals (two age classes combined). These data suggest that the parental behaviour of males imposes an energetic cost which these males hide by increasing their water content. The difference in dry mass of the tissues of parental and non-parental males was most pronounced in the tissues remaining after removal of the muscles from the carcass, i.e. the skin, the vertebral column and the head. While age 1+ fish lose significantly less wet mass over the breeding cycle than age 2+ fish, this loss of mass represented a greater proportion of the body mass of 1+ than of 2+ fish. This may explain why fewer age 1+ fish than age 2+ successfully breed at our field site.

The urgency distribution of an accident and emergency department's workload.

The perceived urgency of 2000 consecutive patients attending the Accident and Emergency Department of the Royal Infirmary, Edinburgh, was assessed using a Linear Analogue Scale. Each patient was assessed by the receptionist, the receiving nurse and the treating doctor. The distribution of urgency rating produced for this patient group was shown to be comparable for each status of assessor, and to correlate with other outcome criteria such as admission and referral rates. The linear scale was also shown to correlate with retrospective assessment using a time-guided category scale. The accident and emergency department workload is predominantly of low urgency (90% less than 5 on a 0-10 scale). Older patients tend to have higher urgency ratings than younger patients and those referred by ambulance, either via general practitioner or 999 calls, have similarly higher urgency distributions. This study provides a basis for the development of a guided category scale for functional triage of accident and emergency departments. Other scoring systems have attempted to similarly quantify the medical component of the workload (Coira & Rothstein, 1983; Peel et al., 1962). However, the complexity of many of these scales, together with the difficulty in usage of so many different scales, begs a reappraisal of the overall triage of patients attending the emergency department. The aim of this study was to look at the perceived urgency distribution of patients presenting to the emergency department. We wished to compare the relative assessment of urgency by various levels of treating staff and to compare those assessments with the referral and outcome of these patients to provide the basis for the development of a comparative Triage Scale.

Photoperiod effects on plasma cortisol levels in Gasterosteus aculeatus.

No diel variations of plasma cortisol levels were found in Gasterosteus aculeatus acclimated to two different photoperiod conditions: 14L:10D and 9L:15D. However, under long photoperiods, G. aculeatus exhibited higher plasma cortisol levels than under short photoperiods, suggesting that elevated plasma cortisol levels are associated with the spring migration and/or reproductive activities. This decrease of plasma cortisol levels is particularly marked in male G. aculeatus. Under the 9L:15D photoperiod, males had lower plasma cortisol levels than females, in contrast to 14L:10D, where no significant sex differences were found.

Evidence for a relationship between geotaxis and seasonal movements in the toad Bufo americanus.

When activity data (i.e. crossings on a strip of fine sand) were compared with data acquired using an inclined plane, a relation of geotaxis to vertical movements was evident. We conclude that Bufo americanus has the ability to use geotaxis in its orientation in areas where topography is abrupt and breeding pools are in the bottom of valleys.