Exploring the variability among smallholder farms in the banana-based farming systems in Bukoba district, Northwest Tanzania

A study was conducted in the high and low rainfall zones in the banana-based farming system in Bukoba district, Tanzania, to explore the variability among household characteristics and farm productivity. Approaches used included a participatory rural appraisal, rapid system characterization, surveys and detailed farm monitoring in two villages, one from each zone in 2005 through 2006. Based on a wealth-ranking, four household resource groups with decreasing wealth were identified: Resource group 1 > Resource group 2 > Resource group 3 > Resource group 4, distinguished by domestic assets, livestock ownership and labour relations. Through principal component analysis using additional variables defined by research team, three Functional Resource Groups from among the four Resource groups at each rainfall zone were identified distinguished by: soil fertility management, food security and farm and off-farm income as important indicators of variability. Further detailed monitoring over 14 months (from March, 2006 through May, 2007) in at least three households from each functional resource group showed that N, P and K balances among land use types and farms were driven by levels of organic inputs used and were also related to wealth and dependence on off-farm activities. However, all households were net food buyers, implying food insecurity. In addition, off-farm activities and off-farm income were important livelihood survival strategie

Connecting in place: older adults' experience of online mindfulness therapy during the COVID-19 pandemic

BACKGROUND: the negative consequences of COVID-19 distancing measures on older adults' mental health and ability to access services have been well documented. Online cognitive behavioural therapy and mindfulness interventions for older adults, carried out during the COVID-19 pandemic, have shown that these interventions are feasible and have potential mental health benefits. However, little research has been carried out on older adults' experiences of engaging with online psychological therapy, and specifically mindfulness therapy. OBJECTIVES: to understand the experience of older adults engaging with online mindfulness therapy during the COVID-19 pandemic. STUDY DESIGN: a qualitative analysis of four community-based focus groups. PARTICIPANTS: thirty-six community dwelling older adults aged between 65 and 85 years were recruited via older adult organisations, charities and the local press. Nineteen percent had long-term physical health conditions, 25% had severe and enduring mental health difficulties and 19% had mild to moderate mental health difficulties. RESULTS: there was a strong sense of group cohesion and community from the participants.Three main themes were identified: reasons for applying, experience of the mindfulness therapy and connecting at home. CONCLUSIONS: the majority of participants were positive about attending a mindfulness group online. This extended to the perceived psychological and social benefits as well as practical considerations. While some participants noted technological hurdles at the beginning of the course, the findings challenge previous studies that suggest older adults are reluctant to engage in online psychological therapies and has important implications for the future provision of psychological therapies to this population

Multidimensional relativistic MHD simulations of Pulsar Wind Nebulae: dynamics and emission

Pulsar Wind Nebulae, and the Crab nebula in particular, are the best cosmic laboratories to investigate the dynamics of magnetized relativistic outflows and particle acceleration up to PeV energies. Multidimensional MHD modeling by means of numerical simulations has been very successful at reproducing, to the very finest details, the innermost structure of these synchrotron emitting nebulae, as observed in the X-rays. Therefore, the comparison between the simulated source and observations can be used as a powerful diagnostic tool to probe the physical conditions in pulsar winds, like their composition, magnetization, and degree of anisotropy. However, in spite of the wealth of observations and of the accuracy of current MHD models, the precise mechanisms for magnetic field dissipation and for the acceleration of the non-thermal emitting particles are mysteries still puzzling theorists to date. Here we review the methodologies of the computational approach to the modeling of Pulsar Wind Nebulae, discussing the most relevant results and the recent progresses achieved in this fascinating field of high-energy astrophysics.Comment: 29 pages review, preliminary version. To appear in the book "Modelling Nebulae" edited by D. Torres for Springer, based on the invited contributions to the workshop held in Sant Cugat (Barcelona), June 14-17, 201

Molecular variability and host distribution of ‘candidatus phytoplasma solani’ strains from different geographic origins

The knowledge of phytoplasma genetic variability is a tool to study their epidemiology and to implement an effective monitoring and management of their associated diseases. ‘Candidatus Phytoplasma solani’ is associated with “bois noir” disease in grapevines, and yellowing and decline symptoms in many plant species, causing serious damages during the epidemic outbreaks. The epidemiology of the diseases associated with this phytoplasma is complex and related to numerous factors, such as interactions of the host plant and insect vectors and spreading through infected plant propagation material. The genetic variability of ‘Ca. P. solani’ strains in different host species and in different geographic areas during the last two decades was studied by RFLP analyses coupled with sequencing on vmp1, stamp, and tuf genes. A total of 119 strains were examined, 25 molecular variants were identified, and the variability of the studied genes was linked to both geographic distribution and year of infection. The crucial question in ‘Ca. P. solani’ epidemiology is to trace back the epidemic cycle of the infections. This study presents some relevant features about differential strain distribution useful for disease monitoring and forecasting, illustrating and comparing the phytoplasma molecular variants identified in various regions, host species, and time periods

Pulsating magneto-dipole radiation of a quaking neutron star powered by energy of Alfven seismic vibrations

We compute the characteristic parameters of magnetic dipole radiation of a neutron star undergoing torsional seismic vibrations under the action of Lorentz restoring force about axis of a dipolar magnetic field experiencing decay. After brief outline of general theoretical background of the model of vibration powered neutron star, we present numerical estimates of basic vibration and radiation characteristics, such as the oscillation frequency, lifetime, luminosity of radiation, and investigate their time dependence upon magnetic field decay. The presented analysis suggests that gradual decrease in frequencies of pulsating high-energy emission detected from a handful of currently monitored AXP/SGR-like X-ray sources can be explained as being produced by vibration powered magneto-dipole radiation of quaking magnetars. \keywords{neutron stars, torsion Alfv\'en vibrations, vibration powered radiation, magnetic field decay, magnetars}Comment: Preprint of article accepted for publication in "Research in Astronomy and Astrophysics" [RAA-Vol.11-No9-(2011)-p.1074

Integrated analysis of Xist upregulation and gene silencing at the onset of random X-chromosome inactivation at high temporal and allelic resolution

To ensure dosage compensation between the sexes, one randomly chosen X chromosome is silenced in each female cell in the process of X-chromosome inactivation (XCI). XCI is initiated during early development through upregulation of the long non-coding RNA Xist, which mediateschromosome-wide gene silencing. Cell differentiation, Xist upregulation and silencing are thought tobe coupled at multiple levels to ensure inactivation of exactly one out of two X chromosomes. Here we perform an integrated analysis of all three processes through allele-specific single-cellRNA-sequencing. Specifically, we assess the onset of random XCI with high temporal resolution indifferentiating mouse embryonic stem cells, and develop dedicated analysis approaches. By exploitingthe inter-cellular heterogeneity of XCI onset, we identify Nanog downregulation as its main trigger and discover additional putative Xist regulators. Moreover, we confirm several predictions of thestochastic model of XCI where monoallelic silencing is thought to be ensured through negativefeedback regulation. Finally, we show that genetic variation modulates the XCI process at multiplelevels, providing a potential explanation for the long-known Xce effect, which leads to preferentialinactivation of a specific X chromosome in inter-strain crosses. We thus draw a detailed picture of thedifferent levels of regulation that govern the initiation of XCI. The experimental and computationalstrategies we have developed here will allow us to profile random XCI in more physiological contexts,including primary human cells in vivo

Signal of Quark Deconfinement in the Timing Structure of Pulsar Spin-Down

The conversion of nuclear matter to quark matter in the core of a rotating neutron star alters its moment of inertia. Hence the epoch over which conversion takes place will be signaled in the spin-down "signal_prl.tex" 581 lines, 22203 characters characteristics of pulsars. We find that an observable called the braking index should be easily measurable during the transition epoch and can have a value far removed (by orders of magnitude) from the canonical value of three expected for magnetic dipole radiation, and may have either sign. The duration of the transition epoch is governed by the slow loss of angular momentum to radiation and is further prolonged by the reduction in the moment of inertia caused by the phase change which can even introduce an era of spin-up. We estimate that about one in a hundred pulsars may be passing through this phase. The phenomenon is analogous to ``bachbending'' observed in the moment of inertia of rotating nuclei observed in the 1970's, which also signaled a change in internal structure with changing spin.Comment: 5 pages, 4 figures, Revtex. (May 12, 1997, submitted to PRL

Subacute pericardial abscess after aortic valve replacement: a case report

BACKGROUND: Purulent pericarditis is an infectious disease, frequently caused by gram-positive bacteria, that is rarely observed in healthy individuals, and is often associated with predisposing conditions. CASE PRESENTATION: Here, we present the case of an Escherichia coli post-surgical localized purulent pericarditis complicated by transient constrictive pericarditis and its diagnostic and therapeutic management. CONCLUSIONS: Our case report focuses on the importance of imaging-guided treatment of purulent pericardial diseases, in particular on the emerging role of 18\u2009F-labelled 2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in pericardial diseases and on the management of transient constrictive pericarditis, often seen after thoracic surgery

Interactions between carnivore species: limited spatiotemporal partitioning between apex predator and smaller carnivores in a Mediterranean protected area

Background: There is need of information on ecological interactions that keystone species such as apex predators establish in ecosystems recently recolonised. Interactions among carnivore species have the potential to influence community-level processes, with consequences for ecosystem dynamics. Although avoidance of apex predators by smaller carnivores has been reported, there is increasing evidence that the potential for competitive-to-facilitative interactions is context-dependent. In a protected area recently recolonised by the wolf Canis lupus and hosting abundant wild prey (3 ungulate species, 20–30 individuals/km2, together), we used 5-year food habit analyses and 3-year camera trapping to (i) investigate the role of mesocarnivores (4 species) in the wolf diet; (ii) test for temporal, spatial, and fine-scale spatiotemporal association between mesocarnivores and the wolf. Results: Wolf diet was dominated by large herbivores (86% occurrences, N = 2201 scats), with mesocarnivores occurring in 2% scats. We collected 12,808 carnivore detections over > 19,000 camera trapping days. We found substantial (i.e., generally ≥ 0.75, 0–1 scale) temporal overlap between mesocarnivores—in particular red fox—and the wolf, with no support for negative temporal or spatial associations between mesocarnivore and wolf detection rates. All the species were nocturnal/crepuscular and results suggested a minor role of human activity in modifying interspecific spatiotemporal partitioning. Conclusions: Results suggest that the local great availability of large prey to wolves limited negative interactions towards smaller carnivores, thus reducing the potential for spatiotemporal avoidance. Our study emphasises that avoidance patterns leading to substantial spatiotemporal partitioning are not ubiquitous in carnivore guilds

Spherically symmetric relativistic MHD simulations of pulsar wind nebulae in supernova remnants

Pulsars, formed during supernova explosions, are known to be sources of relativistic magnetized winds whose interaction with the expanding supernova remnants (SNRs) gives rise to a pulsar wind nebula (PWN). We present spherically symmetric relativistic magnetohydrodynamics (RMHD) simulations of the interaction of a pulsar wind with the surrounding SNR, both in particle and magnetically dominated regimes. As shown by previous simulations, the evolution can be divided in three phases: free expansion, a transient phase characterized by the compression and reverberation of the reverse shock, and a final Sedov expansion. The evolution of the contact discontinuity between the PWN and the SNR (and consequently of the SNR itself) is almost independent of the magnetization of the nebula as long as the total (magnetic plus particle) energy is the same. However, a different behaviour of the PWN internal structure is observable during the compression-reverberation phase, depending on the degree of magnetization=2E The simulations were performed using the third order conservative scheme by Del Zanna et al. (2003).Comment: 11 pages, Latex, 22 Encapsulated PostScript figures, accepted f or publication on A&