Climate change and maize production in the Vaal catchment of South Africa : assessment of farmers’ awareness, perceptions and adaptation strategies

In recent years, maize production in South Africa has faced challenges related to climate change which have prompted farmers to adapt their production activities. We assessed factors informing the adaptive decision-making of maize farmers in the Vaal catchment by examining linkages between farmers’ experiences, their perceptions of climate change and the adaptation strategies they use. Data were collected through semi-structured household-level interviews, key informant interviews and focus group discussions. Catchment climate data were also collected to determine key 30 yr trends (1989-2018) and the farmers’ level of awareness about these trends. Data were analysed using descriptive statistics, Mann-Kendall (MK) test, Sen’s slope test, climate anomalies and multinomial logit modelling. Results suggest that maize farmers in the catchment are aware of climate change (95%), with many of them referring to it as ‘a shift in climate’. This perceived ‘shift’ is supported by meteorological data, as the MK test confirmed a decreasing inter-annual precipitation trend (-0.149) and a decreasing trend at the onset of the maize planting season (-0.167), with temperature showing an increasing trend (0.470). These trends have inspired the adoption of a range of timing-related responses and other farming and off-farm adaptations. Modelling results revealed farmer perception, farmer typology and the nature of maize production (rainfed) as some of the variables with a deciding influence on the nature of the adaptation employed. The study confirms the importance of understanding intersections between qualitative and quantitative variables in triggering adaptive responses. Current strategies need to be expanded and supplemented to improve resilience and prevent maladaptation.The Department of Science and Technology National Research Foundation Innovation Doctoral Scholarshiphttp://www.int-res.com/journals/cr/cr-home2022-01-28hj2021Geography, Geoinformatics and Meteorolog

Safety and Efficacy of Everolimus in Adult Patients with Neuroendocrine Tumors

Neuroendocrine tumors (NETs) consist of a diverse family of tumors which are derived from the neuroendocrine system. Most NETs are well or moderately differentiated tumors with a relatively indolent growth pattern. However, these tumors can cause significant clinical disease due to release of functional products that mediate the carcinoid syndrome and other diverse sequela. They also can grow progressively and cause symptoms from local invasion or distant metastasis. NETs are optimally treated with surgery and somatosatin analogs (SSA’s) to control symptoms but are relatively insensitive to systemic chemotherapy. As a result, patients with advanced unresectable NETs have a poor prognosis. In 2011, two targeted therapies, sunitinib and everolimus were approved in the subset of progressive pancreatic NETs (pNETs). Everolimus is an oral inhibitor of the growth stimulatory mTOR pathway. In Phase 2 trials in NETs and pNETs, everolimus was well tolerated and associated with some response and widespread disease stabilization. In follow-up, randomized Phase 3 trials, everolimus was compared to placebo. In the RADIANT-2 trial, everolimus and a somatostatin analog were used in patients with functional NETs and treatment was associated with an an improvement in progression-free survival (PFS). In the RADIANT-3 trial, patients with pNET were randomized to receive everolimus or placebo along with best supportive care. Everolimus was again associated with improvement in PFS compared to placebo and it has been approved by the FDA for patients with progressive pNET. Everolimus is associated with frequent low grade toxicity but is also notable for increased rates of infection as well as non-infectious pneumonitis. mTOR inhibition with everolimus represents a significant advance in the treatment of advanced neuroendocrine tumors

Integrated assessment of the influence of climate change on current and future intra-annual water availability in the Vaal River catchment

Increasing water demand due to population growth, economic expansion and the need for development puts a strain on the supply capacity of the Vaal River catchment in South Africa. Climate change presents additional challenges in the catchment which supports the country's economic hub, more than 30% of its population and over 70% of its maize production. This study evaluates the influence of climate change on current and future intra-annual water availability and demand using a multi-tiered approach where climate scenarios, hydrological modelling and socio-economic considerations were applied. Results shows exacerbated water supply challenges for the future. Temperature increases of between 0.07 and 5 °C and precipitation reductions ranging from 0.4 to 30% for Representative Concentration Pathways (RCPs) 4.5 and 8.5, respectively, are also predicted by the end of the century. The highest monthly average streamflow reductions (8–10%) are predicted for the summer months beyond 2040. Water Evaluation and Planning (WEAP) simulations project an increase in future water requirements, gaps in future water assurance and highlight limitations in existing management strategies. The study recommends a combination of adaptation plans, climatic/non-climatic stressor monitoring, wastewater-reuse, conservation, demand management and inter-basin transfers to reduce future uncertainty in monthly water sustainability.https://iwaponline.com/jwcchj2021Geography, Geoinformatics and Meteorolog

Signatures of chaotic tunnelling

Recent experiments with cold atoms provide a significant step toward a better understanding of tunnelling when irregular dynamics is present at the classical level. In this paper, we lay out numerical studies which shed light on the previous experiments, help to clarify the underlying physics and have the ambition to be guidelines for future experiments.Comment: 11 pages, 9 figures, submitted to Phys. Rev. E. Figures of better quality can be found at http://www.phys.univ-tours.fr/~mouchet

Instability of vortex array and transitions to turbulent states in rotating helium II

We consider superfluid helium inside a container which rotates at constant angular velocity and investigate numerically the stability of the array of quantized vortices in the presence of an imposed axial counterflow. This problem was studied experimentally by Swanson {\it et al.}, who reported evidence of instabilities at increasing axial flow but were not able to explain their nature. We find that Kelvin waves on individual vortices become unstable and grow in amplitude, until the amplitude of the waves becomes large enough that vortex reconnections take place and the vortex array is destabilized. The eventual nonlinear saturation of the instability consists of a turbulent tangle of quantized vortices which is strongly polarized. The computed results compare well with the experiments. Finally we suggest a theoretical explanation for the second instability which was observed at higher values of the axial flow

How do ecological perspectives help understand schools as sites for teacher learning?

Schools are sites of teachers’ professional learning for both new entrants and experienced practitioners. In this paper, schools are conceptualised as complex, multidimensional ecologies that are constituted by the relations that exist between school leaders, teachers, mentors and all members of the school community. As relational environments, the conditions affecting professional learning – both formal and informal – are constantly dynamic, with multiple and simultaneous interactions taking place between these stakeholders. Interactions are also multi-layered – between the school system, individuals, classrooms, the community and the policy environment. School leaders are a major influence on these dynamics and affect how schools act as sites of professional formation, mediating external policy as well as affecting micro-dynamics within individual school systems. The challenge of realising professional learning within these relational contexts can be viewed as a ‘wicked problem’, a feature of complex systems that resists simplified solutions. In conceptualising a complex ecology at work, we illuminate the relational dynamics with a focus, for all stakeholders within schools, including leaders, on the need to recognise and value the importance of ‘emergence’ in professional learning. This means embracing inevitable uncertainty as a feature of schools as complex systems

Chaos assisted tunnelling with cold atoms

In the context of quantum chaos, both theory and numerical analysis predict large fluctuations of the tunnelling transition probabilities when irregular dynamics is present at the classical level. We consider here the non-dissipative quantum evolution of cold atoms trapped in a time-dependent modulated periodic potential generated by two laser beams. We give some precise guidelines for the observation of chaos assisted tunnelling between invariant phase space structures paired by time-reversal symmetry.Comment: submitted to Phys. Rev. E ; 16 pages, 13 figures; figures of better quality can be found at http://www.phys.univ-tours.fr/~mouchet

SETD2 haploinsufficiency for microtubule methylation is an early driver of genomic instability in renal cell carcinoma

Loss of the short arm of chromosome 3 (3p) occurs early in >95% of clear cell renal cell carcinoma (ccRCC). Nearly ubiquitous 3p loss in ccRCC suggests haploinsufficiency for 3p tumor suppressors as early drivers of tumorigenesis. We previously reported methyltransferase SETD2, which trimethylates H3 histones on lysine 36 (H3K36me3) and is located in the 3p deletion, to also trimethylate microtubules on lysine 40 (aTubK40me3) during mitosis, with aTubK40me3 required for genomic stability. We now show that monoallelic, Setd2-deficient cells retaining H3K36me3, but not aTubK40me3, exhibit a dramatic increase in mitotic defects and micronuclei count, with increased viability compared with biallelic loss. In SETD2-inactivated human kidney cells, rescue with a pathogenic SETD2 mutant deficient for microtubule (aTubK40me3), but not histone (H3K36me3) methylation, replicated this phenotype. Genomic instability (micronuclei) was also a hallmark of patient-derived cells from ccRCC. These data show that the SETD2 tumor suppressor displays a haploinsufficiency phenotype disproportionately impacting microtubule methylation and serves as an early driver of genomic instability. Significance: Loss of a single allele of a chromatin modifier plays a role in promoting oncogenesis, underscoring the growing relevance of tumor suppressor haploinsufficiency in tumorigenesis

Low Complexity Regularization of Linear Inverse Problems

Inverse problems and regularization theory is a central theme in contemporary signal processing, where the goal is to reconstruct an unknown signal from partial indirect, and possibly noisy, measurements of it. A now standard method for recovering the unknown signal is to solve a convex optimization problem that enforces some prior knowledge about its structure. This has proved efficient in many problems routinely encountered in imaging sciences, statistics and machine learning. This chapter delivers a review of recent advances in the field where the regularization prior promotes solutions conforming to some notion of simplicity/low-complexity. These priors encompass as popular examples sparsity and group sparsity (to capture the compressibility of natural signals and images), total variation and analysis sparsity (to promote piecewise regularity), and low-rank (as natural extension of sparsity to matrix-valued data). Our aim is to provide a unified treatment of all these regularizations under a single umbrella, namely the theory of partial smoothness. This framework is very general and accommodates all low-complexity regularizers just mentioned, as well as many others. Partial smoothness turns out to be the canonical way to encode low-dimensional models that can be linear spaces or more general smooth manifolds. This review is intended to serve as a one stop shop toward the understanding of the theoretical properties of the so-regularized solutions. It covers a large spectrum including: (i) recovery guarantees and stability to noise, both in terms of $\ell^2$-stability and model (manifold) identification; (ii) sensitivity analysis to perturbations of the parameters involved (in particular the observations), with applications to unbiased risk estimation ; (iii) convergence properties of the forward-backward proximal splitting scheme, that is particularly well suited to solve the corresponding large-scale regularized optimization problem

Planck 2015 results. XXVII. The Second Planck Catalogue of Sunyaev-Zeldovich Sources

We present the all-sky Planck catalogue of Sunyaev-Zeldovich (SZ) sources detected from the 29 month full-mission data. The catalogue (PSZ2) is the largest SZ-selected sample of galaxy clusters yet produced and the deepest all-sky catalogue of galaxy clusters. It contains 1653 detections, of which 1203 are confirmed clusters with identified counterparts in external data-sets, and is the first SZ-selected cluster survey containing > $10^3$ confirmed clusters. We present a detailed analysis of the survey selection function in terms of its completeness and statistical reliability, placing a lower limit of 83% on the purity. Using simulations, we find that the Y5R500 estimates are robust to pressure-profile variation and beam systematics, but accurate conversion to Y500 requires. the use of prior information on the cluster extent. We describe the multi-wavelength search for counterparts in ancillary data, which makes use of radio, microwave, infra-red, optical and X-ray data-sets, and which places emphasis on the robustness of the counterpart match. We discuss the physical properties of the new sample and identify a population of low-redshift X-ray under- luminous clusters revealed by SZ selection. These objects appear in optical and SZ surveys with consistent properties for their mass, but are almost absent from ROSAT X-ray selected samples