Vector activity and propagule size affect dispersal potential by vertebrates

Many small organisms in various life stages can be transported in the digestive system of larger vertebrates, a process known as endozoochory. Potential dispersal distances of these &ldquo;propagules&rdquo; are generally calculated after monitoring retrieval in experiments with resting vector animals. We argue that vectors in natural situations will be actively moving during effective transport rather than resting. We here test for the first time how physical activity of a vector animal might affect its dispersal efficiency. We compared digestive characteristics between swimming, wading (i.e. resting in water) and isolation (i.e. resting in a cage) mallards (Anas platyrhynchos). We fed plastic markers and aquatic gastropods, and monitored retrieval and survival of these propagules in the droppings over 24 h. Over a period of 5 h of swimming, mallards excreted 1.5 times more markers than when wading and 2.3 times more markers than isolation birds, the pattern being reversed over the subsequent period of monitoring where all birds were resting. Retention times of markers were shortened for approximately 1 h for swimming, and 0.5 h for wading birds. Shorter retention times imply higher survival of propagules at increased vector activity. However, digestive intensity measured directly by retrieval of snail shells was not a straightforward function of level of activity. Increased marker size had a negative effect on discharge rate. Our experiment indicates that previous estimates of propagule dispersal distances based on resting animals are overestimated, while propagule survival seems underestimated. These findings have implications for the dispersal of invasive species, meta-population structures and long distance colonization events.<br />

Wear of permanent incisors with age on commercial Australian Angora goat farms

OBJECTIVE: To quantify if, and to what extent, permanent incisor wear differed with age of goat and farm of origin on commercial Australian Angora goat farms. DESIGN: Observations were made on three Angora goat farms in the wheat-sheep zone of Victoria, each managed according to the farmer's practices. Farmers provided a representative flock of does. METHODS: The proportion and pattern of wear of permanent incisors were recorded and percentage wear calculated. After log(y + 10) transformation, a parsimonious general linear model was developed to relate wear to farm and age, with age considered as a continuous variate. RESULTS: The range in wear of the permanent incisors was 0-100%. For each farm, the most parsimonious model for permanent first incisor wear and average wear of all permanent incisors was a separate straight line relating the transformed incisor wear to the age of doe. The models accounted for 66-73% of variance. On each farm the incisor wear was similar and low for ages up to approximately 4 years. On all farms, the amount of incisor wear increased dramatically with age, although the rate of increase differed with each farm. CONCLUSIONS: Permanent incisor wear increased with age of goat and differed with farm of origin. Angora goat farmers need to be aware of the potential for incisor wear to affect doe production and health.

Sex differences in in-hospital mortality following a first acute myocardial infarction: symptomatology, delayed presentation, and hospital setting

BACKGROUND: Women generally wait longer than men prior to seeking treatment for acute myocardial infarction (AMI). They are more likely to present with atypical symptoms, and are less likely to be admitted to coronary or intensive care units (CCU or ICU) compared to similarly-aged males. Women are more likely to die during hospital admission. Sex differences in the associations of delayed arrival, admitting ward, and mortality have not been thoroughly investigated. <br /><br />METHODS: Focusing on presenting symptoms and time of presentation since symptom onset, we evaluated sex differences in in-hospital mortality following a first AMI in 4859 men and women presenting to three emergency departments (ED) from December 2008 to February 2014. Sex-specific risk of mortality associated with admission to either CCU/ICU or medical wards was calculated after adjusting for age, socioeconomic status, triage-assigned urgency of presentation, blood pressure, heart rate, presenting symptoms, timing of presentation since symptom onset, and treatment in the ED. Sex-specific age-adjusted attributable risks were calculated. <br /><br />RESULTS: Compared to males, females waited longer before seeking treatment, presented more often with atypical symptoms, and were less likely to be admitted to CCU or ICU. Age-adjusted mortality in CCU/ICU or medical wards was higher among females (3.1 and 4.9&nbsp;% respectively in CCU/ICU and medical wards in females compared to 2.6 and 3.2&nbsp;% in males). However, after adjusting for variation in presenting symptoms, delayed arrival and other risk factors, risk of death was similar between males and females if they were admitted to CCU or ICU. This was in contrast to those admitted to medical wards. Females admitted to medical wards were 89&nbsp;% more likely to die than their male counterparts. Arriving in the ED within 60&nbsp;min of onset of symptoms was not associated with in-hospital mortality. Among males, 2.2&nbsp;% of in-hospital mortality was attributed to being admitted to medical wards rather than CCU or ICU, while for females this age-adjusted attributable risk was 4.1&nbsp;%. <br /><br />CONCLUSIONS: Our study stresses the need to reappraise decision making in patient selection for admission to specialised care units, whilst raising awareness of possible sex-related bias in management of patients diagnosed with an AMI.

Economic evaluation alongside a phase II, multi-centre, randomised controlled trial of very early rehabilitation after stroke (AVERT)

<b>BACKGROUND/PURPOSE</b><b>:</b> The effectiveness and costs of very early rehabilitation after stroke are unknown. This study assessed the cost effectiveness of very early mobilisation in addition to standard care (VEM) compared with standard care alone (SC). <b>METHODS:</b> Cost-effectiveness analysis alongside a phase II, multi-centre, randomised controlled trial (RCT) with blinded outcome assessments. Less than 24 h after stroke, patients were recruited from two stroke units and randomised to receive VEM or SC. The intervention continued until discharge or 14 days, whichever was sooner. The efficacy measure was a dichotomised modified Rankin Scale (mRS) at 3 months with mRS &lt; or =2 representing good outcome. Costs were determined from medical records and patient interviews at 3, 6 and 12 months. National average (where available) or local costs were applied for the reference year 2004. Differences in mean total costs at 3 and 12 months were tested using t test assuming unequal variances. An incremental cost-effectiveness ratio was calculated and probabilistic uncertainty analysis was undertaken. <b>RESULTS:</b> The sample consisted of 38 VEM and 33 SC patients. A trend for good outcome with VEM compared to SC was found (adjusted OR 4.10, 95% CI 0.99-16.88, p = 0.051). Patients receiving VEM incurred significantly less costs at 3 months (AUD 13,559) compared with SC (AUD 21,860; p = 0.02). This difference in mean per patient total cost persisted at the 12-month assessment (VEM: AUD 17,564; SC: AUD 29,750; p = 0.03). VEM was found to be a 'dominant' (more effective, less cost) intervention when compared to SC at 3 months. <b>CONCLUSION:</b> These findings provide preliminary evidence that VEM is likely to be cost-effective. A large RCT is currently underway to confirm the cost effectiveness of VEM.<br />

The cost-effectiveness of Australia's active after-school communities program

The objective of this study was to assess from a societal perspective the cost-effectiveness of the Active After-school Communities (AASC) program, a key plank of the former Australian Government's obesity prevention program. The intervention was modeled for a 1-year time horizon for Australian primary school children as part of the Assessing Cost-Effectiveness in Obesity (ACE-Obesity) project. Disability-adjusted life year (DALY) benefits (based on calculated effects on BMI post-intervention) and cost-offsets (consequent savings from reductions in obesity-related diseases) were tracked until the cohort reached the age of 100 years or death. The reference year was 2001, and a 3% discount rate was applied. Simulation-modeling techniques were used to present a 95% uncertainty interval around the cost-effectiveness ratio. An assessment of second-stage filter criteria (&quot;equity,&quot; &quot;strength of evidence,&quot; &quot;acceptability to stakeholders,&quot; &quot;feasibility of implementation,&quot; &quot;sustainability,&quot; and &quot;side-effects&quot;) was undertaken by a stakeholder Working Group to incorporate additional factors that impact on resource allocation decisions. The estimated number of children new to physical activity after-school and therefore receiving the intervention benefit was 69,300. For 1 year, the intervention cost is Australian dollars (AUD) 40.3 million (95% uncertainty interval AUD 28.6 million; AUD 56.2 million), and resulted in an incremental saving of 450 (250; 770) DALYs. The resultant cost-offsets were AUD 3.7 million, producing a net cost per DALY saved of AUD 82,000 (95% uncertainty interval AUD 40,000; AUD 165,000). Although the program has intuitive appeal, it was not cost-effective under base-case modeling assumptions. To improve its cost-effectiveness credentials as an obesity prevention measure, a reduction in costs needs to be coupled with increases in the number of participating children and the amount of physical activity undertaken.<br />