Inter-patch movement in an experimental system: the effects of life history and the environment

An important process for the persistence of populations subjected to habitat loss and fragmentation is the dispersal of individuals between habitat patches. Dispersal involves emigration from a habitat patch, movement between patches through the surrounding landscape, and immigration into a new suitable habitat patch. Both landscape and physical condition of the disperser are known to influence dispersal ability, although disentangling these effects can often be difficult in the wild. In one of the first studies of its kind, we used an invertebrate model system to investigate how dispersal success is affected by the interaction between the habitat condition, as determined by food availability, and life history characteristics (which are also influenced by food availability). Dispersal of juvenile and adult mites (male and female) from either high food or low food natal patches were tested separately in connected three patch systems where the intervening habitat patches were suitable (food supplied) or unsuitable (no food supplied). We found that dispersal success was reduced when low food habitat patches were coupled to colonising patches via unsuitable intervening patches. Larger body size was shown to be a good predictor of dispersal success, particularly when the intervening landscape is unsuitable. Our results suggest that there is an interaction between habitat fragmentation and habitat suitability in determining dispersal success: if patches degrade in suitability and this affects the ability to disperse successfully then the effective connectance across landscapes may be lowered. Understanding these consequences will be important in informing our understanding of how species, and the communities in which they are embedded, may potentially respond to habitat fragmentation

The ratio of soluble fms–like tyrosine kinase 1 to placental growth factor predicts time to delivery and mode of birth in patients with suspected preeclampsia- a secondary analysis of the INSPIRE trial

Background: The ratio of soluble fms–like tyrosine kinase 1 to placental growth factor (sFLT1/PLGF) is a useful biomarker for preeclampsia. Since it is a measure of placental dysfunction, it could also be a predictor of clinical deterioration and fetal tolerance to intrapartum stress. Objectives: We tested the hypothesis that sFLT1/PLGF ratio predicts time to delivery. Secondary objectives were to examine associations between the sFLT1/PLGF ratio and mode of birth, fetal distress, need for labor induction and birthweight z-score. Study design: Secondary analysis of the INSPIRE trial, a randomized interventional study on prediction of preeclampsia/eclampsia in which women with suspected preeclampsia were recruited and their blood sFLT1/PLGF ratio was assessed. We stratified participants into three groups according to the ratio result: category 1 (sFLT1/PLGF≤38); category 2 (sFLT1/PLGF>38 and <85); and category 3 (sFLT1/PLGF≥85). We modelled time from sFLT1/PLGF determination to delivery using Kaplan-Meier curves and compared the three ratio categories adjusting for gestational age at sFLT1/PLGF determination and trial arm with Cox Regression. The association between ratio category and mode of delivery, induction of labour and fetal distress was assessed using a multivariable logistic regression adjusting for gestational age at sampling and trial arm. The association between birthweight z-score and sFLT1/PLGF ratio was evaluated using multiple linear regression. Subgroup analysis was conducted in women with no preeclampsia and spontaneous onset of labor; women with preeclampsia; and participants in the non-reveal arm. Results: Higher ratio categories were associated with a shorter latency from sFLT1/PLGF determination to delivery (37 vs 13 vs 10 days for ratios categories 1-3 respectively), hazards ratio for category 3 ratio of 5.64 (95%CI 4.06-7.84, p<0.001). A sFLT/PlGF ratio≥85 had specificity of 92.7%(95%CI 89.0-95.1%) and sensitivity of 54.72% (95% CI, 41.3-69.5) for prediction of preeclampsia indicated delivery within 2 weeks. A ratio category 3 was also associated with decreased odds of spontaneous vaginal delivery (OR 0.47, 95%CI 0.25-0.89); an almost six fold increased risk of emergency cesarean section (OR 5.89, 95%CI 3.05-11.21); and a three-fold increased risk for intrapartum fetal distress requiring operative delivery or cesarean section (OR 3.04, 95%CI 1.53-6.05) when compared to patients with ratios≤38. Higher ratio categories were also associated with higher odds of induction of labor when compared to ratios category 1 (category 2, OR 2.20, 95%CI 1.02-4.76; category 3, OR 6.0, 95%CI 2.01-17.93); and lower median birthweight z-score. Within subgroups of women a)without preeclampsia and with spontaneous onset of labor and b)women with preeclampsia, the log ratio was significantly higher in patients requiring intervention for fetal distress or failure to progress compared to those who delivered vaginaly without intervention. In the subset of women with no preeclampsia and spontaneous onset of labour, those who required intervention for fetal distress or failure to progress had a significantly higher log ratio than those who delivered vaginaly without needing intervention. Conclusion: The sFLT1/PLGF ratio might be helpful in risk-stratification of patients who present with suspected preeclampsia regarding clinical deterioration, intrapartum fetal distress and mode of birth (including the need for intervention in labour)

An Investigation of Sources of Randomness Within Discrete Gaussian Sampling

This paper presents a performance and statistical analysis of random number generators and discrete Gaussian samplers implemented in software. Most Lattice-based cryptographic schemes utilise discrete Gaussian sampling and will require a quality random source. We examine a range of candidates for this purpose, including NIST DRBGs, stream ciphers and well-known PRNGs. The performance of these random sources is analysed within 64-bit implementations of Bernoulli, CDT and Ziggurat sampling. In addition we perform initial statistical testing of these samplers and include an investigation into improper seeding issues and their effect on the Gaussian samplers. Of the NIST approved Deterministic Random Bit Generators (DRBG), the AES based CTR-DRBG produced the best balanced performance in our tests

Really Trying or Merely Trying

We enjoy first-person authority with respect to a certain class of actions: for these actions, we know what we are doing just because we are doing it. This paper first formulates an epistemological principle that captures this authority in terms of trying to act in a way that one has the capacity to act. It then considers a case of effortful action – running a middle distance race – that threatens this principle. And proposes the solution of changing the metaphysics of action: one can keep hold of the idea that we have first-person authority over what we are doing by adopting a disjunctive account of action

A multicriteria decision analysis comparing pharmacotherapy for chronic neuropathic pain, including cannabinoids and cannabis-based medical products

Background: Pharmacological management of chronic neuropathic pain (CNP) still represents a major clinical challenge. Collective harnessing of both the scientific evidence base and clinical experience (of clinicians and patients) can play a key role in informing treatment pathways and contribute to the debate on specific treatments (e.g., cannabinoids). A group of expert clinicians (pain specialists and psychiatrists), scientists, and patient representatives convened to assess the relative benefit–safety balance of 12 pharmacological treatments, including orally administered cannabinoids/cannabis-based medicinal products, for the treatment of CNP in adults. Methods: A decision conference provided the process of creating a multicriteria decision analysis (MCDA) model, in which the group collectively scored the drugs on 17 effect criteria relevant to benefits and safety and then weighted the criteria for their clinical relevance. Findings: Cannabis-based medicinal products consisting of tetrahydrocannabinol/cannabidiol (THC/CBD), in a 1:1 ratio, achieved the highest overall score, 79 (out of 100), followed by CBD dominant at 75, then THC dominant at 72. Duloxetine and the gabapentinoids scored in the 60s, amitriptyline, tramadol, and ibuprofen in the 50s, methadone and oxycodone in the 40s, and morphine and fentanyl in the 30s. Sensitivity analyses showed that even if the pain reduction and quality-of-life scores for THC/CBD and THC are halved, their benefit–safety balances remain better than those of the noncannabinoid drugs. Interpretation: The benefit–safety profiles for cannabinoids were higher than for other commonly used medications for CNP largely because they contribute more to quality of life and have a more favorable side effect profile. The results also reflect the shortcomings of alternative pharmacological treatments with respect to safety and mitigation of neuropathic pain symptoms. Further high-quality clinical trials and systematic comprehensive capture of clinical experience with cannabinoids is warranted. These results demonstrate once again the complexity and multimodal mechanisms underlying the clinical experience and impact of chronic pain

Brief biopsychosocially informed education can improve insurance workers' back pain beliefs: Implications for improving claims management behaviours

Background: Biopsychosocially informed education is associated with improved back pain beliefs and positive changes in health care practitioners’ practice behaviours. Objective: Assess the effect of this type of education for insurance workers who are important non-clinical stakeholders in the rehabilitation of injured workers. Methods: Insurance workers operating in the Western Australian workers’ compensation system underwent two, 1.5 hour sessions of biopsychosocially informed education focusing on understanding and identifying barriers to recovery of injured workers with musculoskeletal conditions. Back pain beliefs were assessed pre-education, immediately post-education and at three-month follow-up (n = 32). Self-reported and Injury Management Advisor-reported assessment of change in claims management behaviours were collected at the three-month follow-up. Results: There were positive changes in the Health Care Providers’ Pain and Impairment Relationship Scale (p = 0.009) and Back Beliefs Questionnaire (p = 0.049) immediately following the education that were sustained at three-month follow-up. Positive changes in claims management behaviours were supported by self-reported and Injury Management Advisor-reported data. Conclusion: This study provides preliminary support that a brief biopsychosocially informed education program can positively influence insurance workers’ beliefs regarding back pain, with concurrent positive changes in claims management behaviours. Further research is required to ascertain if these changes result in improved claims management outcomes

A pilot of the feasibility and usefulness of an aged obese model for use in stroke research

Background: Animal models of stroke have been criticised as having poor predictive validity, lacking risk factors prevalent in an aging population. This pilot study examined the development of comorbidities in a combined aged and high-fat diet model, and then examined the feasibility of modelling stroke in such rats. Methods: Twelve-month old male Wistar-Han rats (n=15) were fed a 60% fat diet for 8 months during which monthly serial blood samples were taken to assess the development of metabolic syndrome and pro-inflammatory markers. Following this, to pilot the suitability of these rats for undergoing surgical models of stroke, they underwent 30min of middle cerebral artery occlusion (MCAO) alongside younger controls fed a standard diet (n=10). Survival, weight and functional outcome were monitored, and blood vessels and tissues collected for analysis. Results: A high fat diet in aged rats led to substantial obesity. These rats did not develop type 2 diabetes or hypertension. There was thickening of the thoracic arterial wall and vacuole formation in the liver; but of the cytokines examined changes were not seen. MCAO surgery and behavioural assessment was possible in this model (with some caveats discussed in manuscript). Conclusions: This study shows MCAO is possible in aged, obese rats. However, this model is not ideal for recapitulating the complex comorbidities commonly seen in stroke patients

International Construction Measurement Standards: Global Consistency in Presenting Construction Costs

This publication presents an international cost classification system for infrastructure projects. It aims to provide global consistency in classifying, defining, measuring, analysing and presenting the cost of infrastructure projects