Analysing the donor behaviour of a Muslim diaspora in Australia

Diaspora communities are an important source of charitable giving to their original homelands. This study explores a Muslim diaspora's motivations behind donation-giving. A two-year donation dataset of an overseas charity organisation registered in Australia was analysed. Findings show that, overall, donations are significantly related to the prevailing consumer confidence levels (r = 0.4277). However, there was also a strong, inverse correlation (r = - 0.4376) during 2020, suggesting that the plummeting consumer sentiment during COVID-19 did not impact donation revenue. As expected, during periods of religious significance (Ramadan) across both years, donations to the charity increased substantially, with the relative effect of Ramadan calculated as over 800%. This study makes a contribution by providing insights to donor behaviour through the examination of a donation dataset. This study also uses ‘causal impact analysis’ to calculate the effect of Ramadan on donations. Results have implications for the not-for-profit sector in Australia and other countries with Muslim diaspora communities. Limitations and suggestions for future research are also discussed.

Differential regulation of prelimbic and thalamic transmission to the basolateral amygdala by acetylcholine receptors

The amygdalar anterior basolateral nucleus (BLa) plays a vital role in emotional behaviors. This region receives dense cholinergic projections from basal forebrain which are critical in regulating neuronal activity and synaptic transmission. Cholinergic signaling in BLa is thought to occur through both a slow mode of volume transmission as well as a rapid, phasic mode. However, the relative effect of each mode of signaling in BLa is not understood. Here, we used electrophysiology and optogenetics in mouse brain slices to compare regulation of afferent input from cortex and thalamus to the BLa by these two modes of transmission. Phasic ACh release evoked by single pulse stimulation of cholinergic terminals had a biphasic effect on glutamatergic transmission at cortical input, producing rapid nicotinic receptor-mediated facilitation followed by slower muscarinic receptor (mAChR)-mediated depression. In contrast, tonic elevation of ACh through application of the cholinesterase inhibitor physostigmine suppressed glutamatergic transmission at cortical inputs through mAChRs only. This suppression was not observed at thalamic inputs to BLa. In agreement with this pathway-specificity, the mAChR agonist, muscarine more potently suppressed transmission at inputs from prelimbic cortex (PL) than thalamus. Muscarinic inhibition at PL input was dependent on presynaptic M4 mAChRs, while at thalamic input it depended upon M3 mAChR-mediated stimulation of retrograde endocannabinoid signaling. Muscarinic inhibition at both pathways was frequency-dependent, allowing only high frequency activity to pass. These findings demonstrate complex cholinergic regulation of afferent input to BLa that depends upon the mode of ACh release and is both pathway specific and frequency dependent.

Regional Assessment of Carbon Pool Response to Intensive Silvicultural Practices in Loblolly Pine Plantations

Tree plantations represent an important component of the global carbon (C) cycle and are expected to increase in prevalence during the 21st century. We examined how silvicultural approaches that optimize economic returns in loblolly pine (Pinus taeda L.) plantations affected the accumulation of C in pools of vegetation, detritus, and mineral soil up to 100 cm across the loblolly pine’s natural range in the southeastern United States. Comparisons of silvicultural treatments included competing vegetation or ‘weed’ control, fertilization, thinning, and varying intensities of silvicultural treatment for 106 experimental plantations and 322 plots. The average age of the sampled plantations was 17 years, and the C stored in vegetation (pine and understory) averaged 82.1 ± 3.0 (±std. error) Mg C ha−1, and 14.3 ± 0.6 Mg C ha−1 in detrital pools (soil organic layers, coarse-woody debris, and soil detritus). Mineral soil C (0–100 cm) averaged 79.8 ± 4.6 Mg C ha−1 across sites. For management effects, thinning reduced vegetation by 35.5 ± 1.2 Mg C ha−1 for all treatment combinations. Weed control and fertilization increased vegetation between 2.3 and 5.7 Mg C ha−1 across treatment combinations, with high intensity silvicultural applications producing greater vegetation C than low intensity (increase of 21.4 ± 1.7 Mg C ha−1). Detrital C pools were negatively affected by thinning where either fertilization or weed control were also applied, and were increased with management intensity. Mineral soil C did not respond to any silvicultural treatments. From these data, we constructed regression models that summarized the C accumulation in detritus and detritus + vegetation in response to independent variables commonly monitored by plantation managers (site index (SI), trees per hectare (TPH) and plantation age (AGE)). The C stored in detritus and vegetation increased on average with AGE and both models included SI and TPH. The detritus model explained less variance (adj. R2 = 0.29) than the detritus + vegetation model (adj. R2 = 0.87). A general recommendation for managers looking to maximize C storage would be to maintain a high TPH and increase SI, with SI manipulation having a greater relative effect. From the model, we predict that a plantation managed to achieve the average upper third SI (26.8) within our observations, and planted at 1500 TPH, could accumulate ~85 Mg C ha−1 by 12 years of age in detritus and vegetation, an amount greater than the region’s average mineral soil C pool. Notably, SI can be increased using both genetic and silviculture technologies.

Typology and performance of inter-organizational relationships among Ghanaian farmers

This study explored inter-organizational relationships (IOR) between farmers and agri-food processors in Ghana and their relative effect on participating farmers’ performance. The IOR were organized into three broad types: governance (formal/informal); orientation (price/quality/quantity); and structure (direct-to-buyer/farmer-based organization (FBO)/agent). The study showed that about 44% of farmers participated in IOR, and 72% of them use direct-to-buyer relationships compared to 25% and 5% who use FBO and agent. The total exceeds 100% because some farmers used multiple IOR structures. Likewise, more than half of farmers involved in IOR use multiple orientations, with 29%, 81% and 54% of them using orientations involving quantity, quality, and price specifications, respectively. Formal governance IOR accounted for 31% of IOR by governance. On performance, the average farm income of farmers involved in IOR was GHS 3,947, which was 3.1 times higher than non-IOR farmers, and those with formal arrangements had 6.4 times higher average farm income than farmers in informal relationships. IOR with formal governance and quality-price orientation presented positive and statistically significant effects on marginal benefits while producer demographic and socio-economic characteristics did not. These results provide instruction for policymakers and practitioners in helping inform farmers’ participation in IOR that produce superior outcomes.

Higher-order synchronization on the sphere

We construct a system of $N$ interacting particles on the unit sphere $S^{d-1}$ in $d$-dimensional space, which has $d$-body interactions only. The equations have a gradient formulation derived from a rotationally-invariant potential of a determinantal form summed over all nodes, with antisymmetric coefficients. For $d=3$, for example, all trajectories lie on the $2$-sphere and the potential is constructed from the triple scalar product summed over all oriented $2$-simplices. We investigate the cases $d=3,4,5$ in detail, and find that the system synchronizes from generic initial values, for both positive and negative coupling coefficients, to a static final configuration in which the particles lie equally spaced on $S^{d-1}$. Completely synchronized configurations also exist, but are unstable under the $d$-body interactions. We compare the relative effect of $2$-body and $d$-body forces by adding the well-studied $2$-body interactions to the potential, and find that higher-order interactions enhance the synchronization of the system, specifically, synchronization to a final configuration consisting of equally spaced particles occurs for all $d$-body and $2$-body coupling constants of any sign, unless the attractive $2$-body forces are sufficiently strong relative to the $d$-body forces. In this case the system completely synchronizes as the $2$-body coupling constant increases through a positive critical value, with either a continuous transition for $d=3$, or discontinuously for $d=5$. Synchronization also occurs if the nodes have distributed natural frequencies of oscillation, provided that the frequencies are not too large in amplitude, even in the presence of repulsive 2-body interactions which by themselves would result in asynchronous behaviour.

Portfolio Management of Copula-Dependent Assets Based on P(Y < X) Reliability Models: Revisiting Frank Copula and Dagum Distributions

Modern portfolio theory indicates that portfolio optimization can be carried out based on the mean-variance model, where returns and risk are represented as the average and variance of the historical data of the stock’s returns, respectively. Several studies have been carried out to find better risk proxies, as variance was not that accurate. On the other hand, fewer papers are devoted to better model/characterize returns. In the present paper, we explore the use of the reliability measure P(Y<X) to choose between portfolios with returns given by the distributions X and Y. Thus, instead of comparing the expected values of X and Y, we will explore the metric P(Y<X) as a proxy parameter for return. The dependence between such distributions shall be modelled by copulas. At first, we derive some general results which allows us to split the value of P(Y<X) as the sum of independent and dependent parts, in general, for copula-dependent assets. Then, to further develop our mathematical framework, we chose Frank copula to model the dependency between assets. In the process, we derive a new polynomial representation for Frank copulas. To perform a study case, we considered assets whose returns’ distributions follow Dagum distributions or their transformations. We carried out a parametric analysis, indicating the relative effect of the dependency of return distributions over the reliability index P(Y<X). Finally, we illustrate our methodology by performing a comparison between stock returns, which could be used to build portfolios based on the value of the the reliability index P(Y<X).

COVID-19 and self-initiated expatriate health workers: Spanish nurses in Germany

PurposeGiven that the incidence of coronavirus disease 2019 (COVID-19) varies greatly between countries, it becomes relevant to explore self-initiated expatriate (SIE) health workers' perceptions of home vs host country safety during a global pandemic. Thus, the paper aims to study the effects of COVID-19 on the expatriation experience of Spanish SIE nurses in Germany, focussing on perceptions of home and host country safety as push/pull forces on their intentions to repatriate or stay.Design/methodology/approachSemi-structured interviews (n = 10) were conducted with Spanish SIE nurses in Germany between April/June 2020 followed by instant messaging interactions with the same participants in October/November 2020. Data analysis was assisted by NVivo software.FindingsOverloaded by information from social networks about the impact of COVID-19 in Spain compared with the situation in Germany, Spanish SIE nurses had exacerbated feelings of stress, and some reported having experienced guilt for not being in their home country. Nevertheless, the contrasting impact and management of the crisis and its relative effect on health workers and the larger society in Spain and Germany reinforced the nurses' intention to stay in Germany.Research limitations/implicationsThe research offers insights to organisations and public authorities involved with providing support to SIEs during crises, highlighting the implications of SIEs' social networks and dual allegiance to home and host countries during a global health emergency.Originality/valueThe study contributes to the growing literature on SIEs, whilst adding to the research on expatriates' well-being and safety during crises.

Comparative effectiveness and safety of pharmaceuticals assessed in observational studies compared with randomized controlled trials

Background There have been ongoing efforts to understand when and how data from observational studies can be applied to clinical and regulatory decision making. The objective of this review was to assess the comparability of relative treatment effects of pharmaceuticals from observational studies and randomized controlled trials (RCTs). Methods We searched PubMed and Embase for systematic literature reviews published between January 1, 1990, and January 31, 2020, that reported relative treatment effects of pharmaceuticals from both observational studies and RCTs. We extracted pooled relative effect estimates from observational studies and RCTs for each outcome, intervention-comparator, or indication assessed in the reviews. We calculated the ratio of the relative effect estimate from observational studies over that from RCTs, along with the corresponding 95% confidence interval (CI) for each pair of pooled RCT and observational study estimates, and we evaluated the consistency in relative treatment effects. Results Thirty systematic reviews across 7 therapeutic areas were identified from the literature. We analyzed 74 pairs of pooled relative effect estimates from RCTs and observational studies from 29 reviews. There was no statistically significant difference (based on the 95% CI) in relative effect estimates between RCTs and observational studies in 79.7% of pairs. There was an extreme difference (ratio < 0.7 or > 1.43) in 43.2% of pairs, and, in 17.6% of pairs, there was a significant difference and the estimates pointed in opposite directions. Conclusions Overall, our review shows that while there is no significant difference in the relative risk ratios between the majority of RCTs and observational studies compared, there is significant variation in about 20% of comparisons. The source of this variation should be the subject of further inquiry to elucidate how much of the variation is due to differences in patient populations versus biased estimates arising from issues with study design or analytical/statistical methods.